CN118974493A - Heat Pump - Google Patents

Abstract

A heat pump (100) is described, the heat pump comprising: an evaporator (50) for evaporating a fluid to obtain evaporated fluid, wherein the evaporator (50) has an evaporator sump (52); a compressor having a first compressor stage (10) and a second compressor stage (20), wherein the compressor is arranged between the evaporator (50) and a condenser (60) along the flow direction of the evaporated fluid during operation of the heat pump (100) and is configured to compress the evaporated fluid to obtain compressed fluid; and a condenser (60) for condensing the compressed fluid; and An intercooler (40) is connected to an intercooling fluid supply line (3) and has an active element (42), wherein the active element (42) is arranged between the first compressor stage (10) and the second compressor stage (20) and is designed to cause an interaction between an intercooling fluid that can be conveyed through the intercooling fluid supply line (3) and a heated vapor-like fluid that can be output by the first compressor stage (10), and wherein the intercooling fluid supply line (3) extends from the evaporator sump (52) to the active element (42). In addition, a method for operating and manufacturing the heat pump is described.

Description

Heat Pump

Technical Field

The present invention relates to the field of heat pumps and in particular to solutions for improving the efficiency of heat pumps.

Background Art

EP 3203164 describes a heat pump. FIG. 20 shows the prior art from EP 3203164. The heat pump of EP 3203164 operates with water as a refrigerant. Water is led from the sump of the condenser 6′ to the sump of the intercooler via an inlet line 71′. The inlet line 71′ extends from the sump of the intercooler to the sump of the evaporator 2′, thereby obtaining a refrigerant return scheme. Another inlet line 72′ extends from the sump 4a′ of the intercooler 4′ to the sump of the evaporator 2′, thereby obtaining a refrigerant return scheme to the evaporator. The cooling water for showering is led to the upper side of the container 41′ of the intercooler by a pump 4c′ in order to cool the overheated water vapor leaving the compressor 3′. EP 3203164 discloses a direct cooling scheme implemented by direct showering. In direct showering, the overheated steam flowing out of the first compressor is cooled to the saturated steam temperature by showering with water from the sump of the intercooler. Here, droplets can be formed by showering, which are further carried away by the steam in the direction of the second compressor 5 ', and the droplets may damage the second compressor due to pitting at the vane pump. In addition, the overheated steam is cooled in the intercooler. The water collected in the sump of the intercooler therefore almost corresponds to the saturated steam temperature. In order to dissipate the heat of the overheated steam to the saturated steam temperature level, a relatively large surface or a long contact time is required between the water and the steam. Usually, refrigeration equipment is only limited to a limited range of power output. In order to be able to respond to higher and lower refrigeration powers at the same time, it is often necessary to turn on/off the compressor. In EP 3203164B, for example, a flap between different compressors is provided.

Summary of the invention

In the open text "Novel Turbo Compressor for Heat Pump Using Water as Refrigerant and Lubricant" published by T. Shoyama et al. in 2019 (IOP Conf.: Mater. Sci. Eng. 604011010), a compressor for a heat pump with a steam bypass V0 is described, which intercepts steam directly after the compressor (see Figure 21). The steam guide structure extends from the outlet of C2 of the second compressor to the inlet of the first compressor C1.

Usually the power consumption of the first compressor stage is used as a guide variable for the second compressor stage. This causes the two compressor stages (first and second compressor stage) to produce a similar pressure ratio relative to the total pressure ratio, because both rotate almost at the same speed. As a result, the second compressor is not optimally flowed through. This is particularly problematic in the case of high pressure ratios, because differences in the steam volume flow occur due to the ambient temperature and the regulation of the second compressor by the power consumption of the first compressor. Liquefaction and re-evaporation in the intermediate circuit lead to thermodynamic losses, so that the pressure ratio of the compressor stage does not fully contribute to the total compression ratio. This is a problem especially for the second compressor.

The object of the present invention is to provide an improved heat pump which has, in particular, an improved concept for the heat exchange of a fluid, such as a coolant, which circulates in the heat pump.

This object is achieved by a heat pump according to claim 1 .

The heat pump according to the invention comprises: an evaporator for evaporating a fluid to obtain an evaporated fluid, wherein the evaporator has an evaporator sump; a compressor having a first compressor stage and a second compressor stage, wherein the compressor is arranged between the evaporator and the condenser along the flow direction of the evaporated fluid during operation of the heat pump and is configured to compress the evaporated fluid to obtain a compressed fluid; and a condenser for condensing the compressed fluid. In addition, the heat pump comprises an intercooler, which is connected to an intercooling fluid supply line and has an active element, wherein the active element is arranged between the first compressor stage and the second compressor stage and is configured to cause an interaction between the intercooling fluid that can be conveyed through the intercooling fluid supply line and the heated vaporous fluid that can be output by the first compressor stage, and wherein the intercooling fluid supply line extends from the evaporator sump to the active element.

It goes without saying that aspects described with respect to the heat pump can also be implemented as method steps and vice versa. Further details are discussed within the framework of the following description of the figures.

BRIEF DESCRIPTION OF THE DRAWINGS

The preferred embodiments of the present invention are explained in detail below with reference to the accompanying drawings.

FIG1 shows a hydraulic diagram of a heat pump according to the invention;

FIG. 2 shows an enlarged detail of the hydraulic diagram according to FIG. 1 , wherein the steam flap (upper branch line) and the steam bypass flap (lower branch line) are marked;

FIG3 shows a schematic test bench for testing the functionality of a compressor of a heat pump under actual operating conditions;

FIG4 shows a schematic structure of an N-stage compression structure, wherein N=3 in the illustrated case;

FIG5 shows a hydraulic diagram of an N-stage compression structure;

FIG6 shows a three-dimensional view of a heat pump according to the present invention;

FIG. 7 shows a top view ( FIG. 7 a ) and a side view ( FIG. 7 b ) of a cross-section reducing element and a joint of the cross-section reducing element ( FIG. 7 c );

FIG8 shows a hydraulic diagram in which the circuit of the indirect intercooling section is marked;

FIG9 shows a hydraulic diagram of an indirect intercooler together with an indirect heat transfer device;

FIG10 shows a simplified diagram of a side view of a heat transfer tube;

FIG11 shows a diametrical perspective view of a heat exchanger;

FIG. 12 shows a hydraulic diagram from which a feeding scheme for an intercooler is derived, wherein the intercooler is fed from the evaporator sump;

FIG. 13 shows a hydraulic diagram from which the feeding scheme for the intercooler is derived, with a heat exchanger shown, wherein the intercooler is fed from the evaporator sump;

FIG. 14 shows a hydraulic diagram from which a feeding concept for an intercooler is derived with additional filling bodies and/or additional intercoolers, wherein the intercooler is fed from the evaporator sump;

FIG15 shows a family of compressor characteristic curves;

FIG16 shows a three-dimensional envelope surface for the corrected mass flow;

FIG. 17 shows a three-dimensional diagram for determining the volume flow for ascertaining the corrected mass flow;

FIG18 shows a hydraulic diagram highlighting the temperature sensor for piloting the second compressor;

FIG19 shows a diagram for illustrating a regulation scheme for a compressor stage of a heat pump;

FIG. 20 shows a hydraulic diagram of a heat pump known from the prior art; and

FIG. 21 shows a hydraulic diagram of a heat pump known from the prior art with a steam bypass.

DETAILED DESCRIPTION

Various aspects of the invention described here are described below in Figures 1 to 15. In the present application, the same reference numerals refer to the same or identically acting elements, wherein not all reference numerals necessarily have to be shown again in all figures if they occur repeatedly.

The heat pump 100 according to the invention is described in the overview of the attached FIGS. 1 to 19 , wherein various aspects of the heat pump according to the invention are viewed from different sides in the various FIGS. 1 to 19 in order to present various aspects of the embodiment of the heat pump according to the invention in an overview. The various aspects of the embodiment can be interchanged with respect to one another as desired.

FIG. 1 shows a hydraulic diagram of a heat pump 100 according to the invention. In the hydraulic diagram according to FIG. 1 , a first compressor stage 10 and a second compressor stage 20 can be seen. The first compressor stage 10 and the second compressor stage 20 are connected to each other via a steam channel 30. The steam channel preferably has a curved shape with a groove 32. Mathematically, the steam channel has at least one inflection point in the groove 32, wherein the curvature is zero in at least one inflection point. According to the hydraulic diagram according to FIG. 1 , an intercooler 40 is arranged in the groove 32. The intercooler 40 comprises an active element 42 and an intercooler sump 44. The intercooler sump 44 for collecting fluid and the active element 42 of the intercooler 40 are coupled to each other via a first intercooler line 46, wherein the fluid can be guided from the intercooler sump 44 to the active element 42 via the first intercooler line 46, so as to shower the compressed fluid from the first compressor stage 10 for cooling purposes, which is guided to the second compressor stage 20 in particular in the steam channel 30. Furthermore, a second intercooler line 48 is provided starting from the intercooler sump 44 . The second intercooler line 48 leads from the intercooler sump 44 to a ball bearing adapter 49 for cooling the ball bearing adapter 49 .

The hydraulic diagram according to FIG. 1 further shows an evaporator 50 assigned to the first compressor stage 10. The evaporator 50 comprises an evaporator sump 52. The evaporator 50 comprises an upper evaporator part 54 above the evaporator sump 52, in which the first compressor stage 10 is arranged. In the evaporator 50, a pipeline 56 is arranged above the evaporator sump 52, which is arranged in a matrix shape above the evaporator sump 52 according to the cross-sectional view shown in the hydraulic diagram according to FIG. 1. The pipeline 56 above the evaporator sump 52 can be flowed through by the fluid to be cooled. A wetting device 58 is arranged above the pipeline to sprinkle the pipeline 56 with the fluid from the evaporator sump 52. A first evaporator line 59 is provided from the evaporator sump 52 to the wetting device 58, which first evaporator line guides the fluid from the evaporator sump 52 to the wetting device 58. After the shower line 56 , the fluid discharged via the shower device 58 can be collected in the evaporator sump 52 and fed back to the circuit of the heat pump 100 .

The hydraulic diagram according to FIG. 1 also shows a bridging channel 62 for bridging the second compressor stage 20 between the first compressor stage 10 and the condensing machine 60. Through the bridging channel 62, the compressed fluid can be directly guided to the condensing machine 60 after exiting the first compressor stage 10. The condensing machine 60 includes a condensing machine sump 64 for collecting the fluid. A pipe 56 is arranged above the condensing machine sump 64. However, the pipe 56 assigned to the condensing machine does not have a wetting device. The pipe 56 assigned to the condensing machine 60 is flowed through by the fluid to be heated.

Further features of the hydraulic diagram according to FIG. 1 are described below in conjunction with further advantageous embodiments of the heat pump 100 .

2 shows an enlarged detail of the hydraulic diagram according to FIG. 1 , wherein the cross-sectional reducing element 70 (upper branch) and the steam transfer flap 90 (lower branch) are marked. In the open state of the steam transfer flap 90, the steam-like fluid can be conducted from the condenser 60 to the evaporator 50 via the steam-conducting line 92. In the open state of the cross-sectional reducing element 70, the steam-like fluid can be conducted directly to the condenser 60 via the bridging channel 62.

According to a preferred embodiment, the heat pump 100 includes an evaporator 50 for evaporating a fluid so as to obtain an evaporated fluid, wherein the evaporator 50 has an evaporator sump 52. In addition, the heat pump 100 includes a condenser 60 for condensing the evaporated fluid compressed by the N-stage compressors 10, 80, 20, wherein the condenser 60 has a condenser sump 64, a condensation area 66 and a holding area 67, which is used to hold the vapor-like fluid remaining after the condensation area 66. The N-stage compressors 10, 20, 80 include N compressors, wherein N is a natural number greater than or equal to one, wherein the N-stage compressors 10, 20, 80 are arranged between the evaporator 50 and the condenser 60. In addition, the heat pump 100 includes a steam channel 30, which couples at least two compressors of the N-stage compressors 10, 20, 80 between the evaporator 50 and the condenser 60. FIG4 shows, for example, N compressor stages, 10, 20, 80, where N = 3. The heat pump 100 also includes a steam-conducting line 92, which is arranged between the condenser 60 and the evaporator 50 in order to conduct the steam-like fluid from the holding area 67 of the condenser 60 into the evaporator 50. FIG2 and FIG4 show, for example, a single steam-conducting line 92, in which a steam transfer flap 90 is arranged.

FIG. 3 shows a schematic test bench, which is used to test the functionality of a single compressor of a heat pump 100 under actual operating conditions. According to the test bench 300 of FIG. 3 , N=1. The test bench 300 includes a compressor 301 to be tested and at least one pressure sensor 302 for measuring the compression pressure of a compressed fluid. In addition, the test bench 300 includes at least one temperature sensor 303 for measuring the temperature of the compressed fluid. At least one pressure sensor 302 and at least one temperature sensor 303 are arranged near the compressor 301 to be tested. A fluid line 15 is led into the test bench 303 and a fluid line 15 is led out of it to guide the fluid, especially the cooling water, to the pipeline 56 or to be discharged from it. The flow in the fluid line 15 is adjusted according to the liquefaction pressure. Preferably, the fluid line 15 of the test bench 300 is connected to a cold water ring line (at a water temperature of approximately 17°). The test bench 300 includes a Jacob pipe, which includes a K4-liquefier. Preferably, the Jacob tube has a height of up to 650 mm, especially 600 mm, and a diameter of up to 600 mm, especially 500 mm or 550 mm. In addition, the test bench includes another Jacob tube, which has a height of up to 300 mm, especially 240 mm, and a diameter of up to 600 mm, especially 500 mm or 550 mm. The Jacob tube is arranged on a container 45, in which the fluid occupies a fluid level 51. A temperature sensor 303 for measuring the bottom tank temperature in the container 45 is arranged in the container 45. At least one filling body 7 is arranged above the fluid level 51. The filling body 7 preferably includes a plurality of individual filling bodies, which are arranged to make steam flow through at a larger surface, so that the steam is particularly advantageously condensed. The fluid level 51 is set in the container 45 so that a spacing is formed between the liquid fluid and the tube wall in the pipeline 306 that delivers the fluid to the container 45. This spacing forms a steam flow-through structure 304 between the water level and the tube wall. The pipe 306 establishes a connection between the outlet of the compressor 301 to be tested and the inlet relative to the container 45 in order to return the evaporated fluid from the compressor 301 to be tested to the container 45. The pipe 306 is particularly implemented in two parts, wherein a throttle valve 307 is arranged between the two pipe sections in order to set the resistance of the evaporated fluid. In addition, the evaporation temperature is set by means of the throttle valve 307. The connection 311 of the pipe 306 for the compressor 301 to be tested is configured so that different cross sections of different compressors 301 can be connected to the pipe 306. The test bench 300 also has a geometric structure, which serves as a return 308 for the condensed fluid from the compressor 301 to be tested. In addition, an active element 43 for showering the evaporated fluid is arranged in the pipe 306. The fluid is pumped from the container 45 into the active element 42 of the test bench 300 by means of a pump 310 and an associated line. The test bench also includes a sensor 309, which is in particular a volume flow sensor, in order to measure the volume flow of the evaporated fluid. A connected control device receives the measurement signal of the volume flow sensor and primarily determines a control signal from it in order to predetermine a target speed for the compressor.

Preferably, a holding area 67 with condensed working fluid is arranged in the condenser 60 between the condensation area 66 and the condenser sump 64. The opening 65 of the steam-conducting line 92 is arranged in the holding area 67 above the filling state 68 of the working fluid in the condenser sump 64, in particular the fluid level (51). The opening 65 of the steam-conducting line 92 comprises a channel section which projects through the condenser sump 64 into the holding area 67 in order to conduct the evaporated, i.e. non-condensed, fluid through the steam-conducting line 92 to the evaporator 50.

A condenser sump 64 with condensed working fluid is preferably arranged in the condenser 60. A steam-conducting line 92 extends from the holding area 67 through the condenser sump 64 and is guided out of the condenser through a wall, preferably the bottom, of the condenser 60. FIGS. 2 and 4 show, for example, how the steam-conducting line 92 extends through the bottom of the condenser sump 64. It is conceivable that the steam-conducting line 92 extends through the condenser sump 64 through a wall, in particular a side wall.

The condenser 60 preferably has a tube bundle 56a or a spiral pipe arrangement 56b, through which the liquid to be heated can flow, wherein the tube bundle 56a or the spiral pipe arrangement 56b is arranged laterally with respect to the opening 65 of the steam-conducting line 92, and wherein the intake pipe 12 of a compressor of the N-stage compressor 10, 20, 80 is arranged above the tube bundle 56a or the spiral pipe arrangement 56b. The tube bundle 56a or the spiral pipe arrangement 56b is also referred to as a pipe 56 in the present case.

Preferably, the steam-conducting line 92 has an opening 55 into the evaporator 50, wherein the opening 65 is arranged in the evaporator 50 above the evaporator sump 52. The steam-conducting line 92 therefore has two openings 55, 65, wherein one opening leads through the condenser sump 64 and the other opening 55 opens into the evaporator 50 above the evaporator sump 52. This can be seen, for example, from FIGS. 2 and 4.

Preferably, a tube bundle 56a for the liquid to be cooled and a wetting device 58 for wetting the tube bundle 56a are arranged in the evaporator 50, wherein the opening 55 of the steam-conducting line is arranged in the evaporator 50 in such a way that the steam-like fluid entering the evaporator 50 through the opening 55 impinges laterally on the tube bundle 56a and/or that the steam-like fluid exiting from the steam-conducting line 92 enters a wetting region 57 which is at least partially wetted by the wetting device 58. As can be seen, for example, from FIG. 1 , FIG. 2 or FIG. 4 , the fluid is supplied from the evaporator sump 52 to the wetting device 58 via a first evaporator line 59 between the evaporator sump 52 and the wetting device 58. After wetting the tube bundle 56a in the evaporator 50, the fluid used for wetting can be collected again via the evaporator sump 52 and supplied again to the circuit of the heat pump 100.

Preferably, each compressor of the N-stage compressor 10, 20, 80 has its own shaft, on which the corresponding compressor of the N-stage compressor 10, 20, 80 can be operated during operation and can be controlled individually. As can be seen, for example, from FIG. 1, FIG. 2 or FIG. 4, each compressor has its own motor M. The compressors of the N-stage compressor 10, 20, 80 can therefore be operated independently of each other or individually just not operated.

Preferably, the N-stage compressor 10, 20, 80 comprises N compressors connected in series, wherein the steam guide line 92 is configured as a single steam guide line 92 and guides the steam-like fluid that has been brought from the last stage to the condenser 60 from the condenser 60 to the evaporator 50 (see FIGS. 2, 4 and 5). FIG. 5 shows a hydraulic diagram of the N-stage compression structure. FIG. 5 shows, for example, that the cross-sectional reducing element 70 is configured as a valve. The N-stage compressor 10, 20, 80 is shown as N compressors connected in series, which are connected between the evaporator 50 and the condenser 60.

Preferably, at least two compressors of the N-stage compressors 10, 20, 80 are connected by a steam channel 30 and an intercooler 40 is arranged between the two compressors to cool the steam-like fluid (see Figure 4). Each intercooler 40 includes an active element 42 and an intercooler sump 44 (see Figure 4). The intercooler sump 44 is respectively for collecting fluid, and the active elements 42 of the corresponding intercooler 40 are coupled to each other through the first intercooler line 46, wherein the fluid can be guided from the intercooler sump 44 to the active element 42 through the first intercooler line 46. After passing through the corresponding active element 42, the fluid can be captured by the intercooler sump 44. The fluid can then be resupplied to the circuit of the heat pump 100. In Figure 5, for reasons of clarity, the intercoolers 40 are respectively shown between the compressors of the N-stage compressors 10, 20, 80.

Preferably, the intercooler 40 is arranged in the recess 32 of the steam channel 32 and has an intercooler sump 44 and an active element 42, wherein the active element 42 is designed to cause an interaction between an intercooler fluid (which can flow from the intercooler sump 44 or from the evaporator sump 52 or from the condenser sump 64 into the active element 42 via a supply line, in particular a first intercooler line 46) and a heated vaporous fluid that can be discharged by the compressor, wherein the interaction causes in particular cooling of the vaporous fluid discharged by the compressor by the intercooler fluid (see FIGS. 2 and 4). The vaporous fluid is cooled by the intercooler 40 before it is sucked in by the second compressor stage 20 in the steam channel 30.

Preferably, each intercooler 40 has an intercooling sump 44 and an active element 42 and is arranged in its own recess 32 in the steam channel 30, in particular each intercooler 40 has its own first intercooler line 46 for the active element 42. The first intercooler line 46 can also be referred to as a transfer line. In particular, the transfer lines, i.e., the first intercooler lines 46, can also be connected to one another in a plurality of intercooling sumps 44 (not shown in the figure), so that the transfer lines then form only one transfer line in total.

Preferably, the steam channel 30 between the two compressors has a curved shape with grooves 32, so that the fluid flows through the steam channel 30 at the intermediate cooling sump 44. Condensed fluid can be collected in the intermediate cooling sump 44.

Preferably, the steam guiding line 92 and the steam channel 30 are separated from each other in terms of fluid. Separated from each other in terms of fluid currently means that the steam guiding line 92 and the steam channel 30 are not guided into each other, which will achieve sufficient mixing of the fluid. Therefore, the steam guiding line 92 and the steam channel 30 are drawn with dotted lines in Figures 2 and 4, for example, to show that the steam guiding line 92 and the steam channel 30 are separated from each other. Note that the steam guiding line 92 and the steam channel 30 form a loop in which the fluid circulates in the heat pump 100. One steam channel 30 or a plurality of steam channels 30 are arranged in the upper branch line between the evaporator 50 and the condenser 60. The steam guiding line 92 is arranged in the lower branch line between the evaporator 50 and the condenser 60.

Preferably, the further N compressors are arranged in such a way that another compressor of the N compressors is connected in series with the first compressor of the N-stage compressor 10, 20, 80 by switching the switch to the open state. In FIG. 5 , the n+1 compressor is schematically drawn relative to the first compressor 10. The n+1 compressor is drawn with a dotted line, which should indicate the individual compressors that follow the N-stage compressors 10, 20, 80. The present first compressor stage 10 comprises a first compressor. The second compressor stage comprises a second compressor. The n-th compressor stage comprises an n-th compressor, wherein n is a natural number.

Preferably, a bridging flap 90 is arranged in the steam conducting line 92, which can be switched to an open position, an intermediate position for conducting a steam-like fluid from the condenser 60 to the evaporator 50, or can be switched to a closed position for preventing the steam-like fluid from being conducted into the evaporator. Similar to the cross-sectional reducing element 70, the bridging flap 90 can be designed as a partition or a wing door or a non-return valve or as a valve, as shown, for example, in FIG. 5. The heat pump 100 also includes a control unit for controlling the bridging flap 90 into an open position, an intermediate position or a closed position.

The bridging flap 90 is preferably designed as a controlled bridging valve, which can be acted upon by means of a control unit in order to operate near the boundary line of the compressor characteristic diagram 170 of the compressor 10, 20, 80 assigned to the N-stage. For example, the embodiment of the bridging flap 90 as a controlled bridging valve is shown in FIG5. The bridging flap 90 can also be referred to as a steam transfer flap 90 in the present case.

The compressor characteristic curve group 170 assigned to the compressor 10, 20, 80 of the N-stage specifies the relationship between the pressure ratio and the mass flow. For example, such a compressor characteristic curve group 170 is shown in FIG. The compressor characteristic curve group 170 should be understood as a three-dimensional diagram, in which the third dimension is reflected by the shading in the two-dimensional coordinate system, which is expanded by the pressure ratio PiC and the especially corrected mass flow WcCorr. The pressure ratio PiC describes the ratio of the pressure between the evaporator 50 and the condenser 60, that is, between the compressor stages 10, 20, 80. In the compressor characteristic curve group 170, there is a pump limit 171, which shows a monotonically increasing function between the mass flow and the pressure ratio. The bridging flap 90 is controlled to ensure that the pressure ratio is less than the limit pressure ratio for a certain mass flow, which is assigned to the determined mass flow according to the function. In FIG. 15, the dotted line 172 shows the line of the same speed under the measured evaporation temperature of 18°.

The control unit is preferably configured to switch the bridging flap 90 into a closed position, an open position, or an intermediate position in order to keep the load of the N-stage compressor 10, 20, 80 at least at a load target value during operation. The pump limit 171 can in particular describe the load target value, which can in particular also be a function that depends on the mass flow WcCorr. In particular, the control unit is configured to control the bridging flap 90 so that the operation of the heat pump 100 is carried out essentially along the pump limit 171 or in a range that is slightly shifted towards a larger mass flow WcCorr, so that the operation of the compressor below its absorption limit is prevented in an advantageous manner.

The control unit is preferably configured to open the bridging flap 90 when the load of the N-stage compressor 10, 20, 80 is below the load target value; or to close the bridging flap 90 when the load of the N-stage compressor 10, 20, 80 exceeds the load target value to generate an additional load; or to control the intermediate position of the bridging flap 90 according to the load target value being below. It can be achieved that the heat pump is basically operated along the pump limit 171. For example, when the load of the N-stage compressor 10, 20, 80 deviates from the load target value by up to 5%, the bridging flap 90 can be switched to the intermediate position. This can be achieved starting from the open or closed position of the bridging flap 90. The load target value describes the load of the heat pump 100 during operation, which is achieved at least by the N-stage compressor 10, 20, 80.

Preferably, in a two-stage compressor 10, 20, as shown, for example, in FIG. 2, when the bridging flap 90 is open, the second compressor is switched off, or in a multi-stage compressor (as shown, for example, in FIG. 4 or FIG. 5), when the bridging flap 90 is open, all stages except the first stage 10 are switched off. As soon as all compressor stages except one compressor stage are switched off, the bridging flap 90 is opened. As soon as at least one further compressor stage is switched on in addition to the already operating compressor stage, the bridging flap 90 is closed or, if necessary, switched to an intermediate position. For example, the first compressor 10 can be controlled as a function of the rotational speed of the compressor drive in order to adapt the rotational speed of the first compressor stage 10 to the required power of the first compressor 10.

FIG. 6 shows a three-dimensional view of a heat pump 100 according to the invention. The heat pump 100 comprises a first compressor stage 10 and a second compressor stage 20. The first compressor stage 10 and the second compressor stage 20 are connected to each other via a curved steam channel 30, wherein the steam channel 30 has an intercooler 40. In addition, it can be seen from the view of FIG. 6 that the first compressor stage 10 is connected to the condenser 60 via a crossover channel 62, wherein a cross-sectional reduction element 70 is arranged in the crossover channel 62. The heat pump 100 has also been described with reference to FIG. 1. The view according to FIG. 6 does not allow all specific details to be obtained, which are disclosed, for example, according to the hydraulic diagram of FIG. 1. However, the heat pump 100 shown in FIG. 6 can be derived from the size ratio, so that, for example, the steam channel 30 has an average diameter, which corresponds approximately to half the width of the condenser. In this regard, for the explanation of FIG. 6, reference is also made to the description of FIG. 1 or other views showing the hydraulic diagram of the heat pump 100 according to the invention.

A preferred embodiment of the heat pump 100 comprises an evaporator 50 for evaporating a fluid in order to obtain an evaporated fluid. In addition, the heat pump 100 comprises a condenser 60 for condensing a compressed fluid. In addition, the heat pump 100 comprises a compressor having a first compressor stage 10 and a second compressor stage 20, wherein the compressor is arranged between the evaporator 50 and the condenser 60 along the flow direction of the evaporated fluid in the operation of the heat pump 100 and is configured to compress the evaporated fluid in order to obtain a compressed fluid. According to the suggestion, a cross-over passage 62 is arranged between the first compressor stage 10 and the condenser 60 in order to cross-over the second compressor stage 20, wherein a cross-sectional reduction element 70 is arranged in the cross-over passage 62 in order to set the cross-sectional area of the cross-over passage 62 in order to adjust the flow of the compressed fluid from the first compressor stage 10 to the condenser 60. After exiting the first compressor stage 100, the compressed fluid can therefore be directed directly to the condenser 60 as long as the cross-sectional reduction element 70 occupies an open position. In particular, the cross-section reducing element 70 is in the open position when the second compressor stage 20 is not in operation, ie, is in the switched-off state.

Preferably, the first compressor stage 10 and the second compressor stage 20 are connected via a steam channel 30 (see also the description with respect to FIG. 1 ). The steam channel 30 is designed to be curved, in particular banana-shaped, that is to say arched. The steam channel 30 can have a recess 32 in which a container 45 or intercooler sump 44 is arranged in order to collect the fluid passing through the steam channel 30 as soon as condensation occurs in the gaseous fluid passing through the steam channel 30. By arranging the container 45 in the recess 32, the condensed fluid can be automatically guided into the container 45 by utilizing gravitational forces, in particular without further technical measures.

Preferably, the crossover channel 62 has an opening into the first compressor stage 10, wherein the first compressor stage 10 has an intake sleeve 12 for taking in the evaporated fluid and a guide chamber 14 in order to guide the vaporous compressed fluid into the crossover channel 62. The intake sleeve 12 can be designed conically, wherein a first diameter is arranged in the intake region of the intake sleeve 12 for taking in the fluid and a second diameter of the intake sleeve 12 is subsequently connected to the guide chamber 14. In particular, the first diameter is designed to be larger than the second diameter. In the present case, the first diameter is the largest diameter 16 and the second diameter is the smallest diameter 17. The guide chamber 14 is arranged transversely, in particular substantially orthogonally, to the second diameter of the intake sleeve 12.

Preferably, the condenser 60 has a line 56. The line 56 is preferably designed as a tube bundle 56a or a spiral line arrangement 56b, through which the liquid to be heated can flow, wherein the tube bundle 56a or the spiral line arrangement 56b is arranged laterally with respect to the other opening of the bridging channel 62, and wherein the suction casing 12 of the compressor of the second compressor stage 20 is arranged above the tube bundle 56a or the spiral line arrangement 56b.

The other opening of the jumper channel 62 is preferably arranged in such a way that the vaporous fluid entering the condenser 60 through the other opening hits the tube bundle 56 laterally. By arranging the pipe 56, that is, the tube bundle 56a or the spiral pipe arrangement 56b laterally in the condenser 60 with respect to the other opening of the jumper channel 62, the evaporated compressed fluid directly comes out and hits the pipe 56 after passing through the jumper channel 62, where the evaporated and compressed fluid can be cooled. By being able to flow through the pipe 56 with the fluid to be heated, heat transfer from the evaporated and compressed fluid that hits the pipe 56 laterally through the jumper channel 62 to the fluid to be heated that flows through the pipe is achieved. When the evaporated and compressed fluid hits the pipe 56, the evaporated and compressed fluid is cooled, so that condensation can occur. The fluid condensed at the pipe 56 can drip into the condenser sump 64, especially due to gravity.

Preferably, the cross-section reducing element 70 is designed to adopt a closed position or an open position depending on the operation of the second compressor stage 20, wherein the cross-section reducing element 70 is designed to adopt the closed position when the second compressor stage 20 is switched on or to adopt the open position when the second compressor stage 20 is switched off. Depending on the operation of the second compressor stage 20, the cross-section reducing element 70 can be switched into the closed position or the open position. It is also conceivable that the cross-section reducing element 70 is switched into an intermediate position, i.e. a position between the open position and the closed position, in particular when the second compressor stage 20 is switched off (switched off) or opened (switched on).

The cross-sectional reducing element 70 is preferably prestressed in the closed position by means of a spring element (not shown). As soon as the second compressor stage 20 is disconnected, the prestressed spring element can relax, in particular due to the lack of suction of compressed fluid from the first compressor stage 10 through the steam channel 30, so that the cross-sectional reducing element 70 transitions into the open position. The compressed fluid from the first compressor stage 10 can then pass through the bridging channel 62, thereby bridging the second compressor stage 20.

Preferably, the cross-sectional reduction element 70 is a flap or a partition or a wing door or a check valve. FIG. 7 shows a top view of the cross-sectional reduction element 70 in FIG. 7a, and a side view of the cross-sectional reduction element 70 in FIG. 7b. The cross-sectional reduction element 70 is arranged between the outlet of the first compressor stage 10 and the condensing machine 60 in the cross-sectional passage 62 (see, for example, FIG. 1, FIG. 2 or FIG. 4). The diameter 72 of the cross-sectional reduction element 70 (as shown in FIG. 7a) can correspond to the diameter of the cross-sectional passage 62 or be smaller than the diameter of the cross-sectional passage 62. The diameter of the cross-sectional passage 62 can have, for example, 10 mm. It goes without saying that the diameter of the cross-sectional passage 62 can also have other diameters. In the side view of the cross-sectional reduction element 70 (as shown in FIG. 7b), the diameter 72 of the cross-sectional reduction element 70 is configured to be smaller than the diameter of the cross-sectional passage 62. FIG. 7c shows a partial view of the joint of the cross-sectional reduction element 70 of FIG. 7b, which is used to control the cross-sectional reduction element 70 to an open position or a closed position. Further requirements for the cross-section reducing element 70 can be derived from DIN EN ISO 5211, for example.

The heat pump 100 preferably has a control unit for controlling the cross-section reducing element 70 into an open position or a closed position. Depending on the design of the cross-section reducing element 70 as a flap or a partition or a wing door or a non-return valve, the control unit is designed to actuate the flap or the partition or the wing door or the non-return valve. In the design as a partition, for example, the control unit is designed to increase or reduce the diameter of the partition.

Preferably, the first compressor stage 10 is configured to build up a maximum tolerable pressure, and the cross-sectional reducing element 70 is configured to assume an open position when the pressure ratio between the condenser pressure _T12 and the evaporator pressure _T11 is less than the maximum tolerable pressure of the first compressor stage, so as to guide the compressed fluid from the first compressor stage 10 to the condenser 60 through the crossover channel 62. The pressure ratio between the condenser pressure _T12 and the evaporator pressure _T11 can be calculated, for example, by measuring the temperature. In particular, the temperature _T11 in the evaporator sump 52 and the temperature _T12 in the condenser sump 64 can be measured respectively, so as to determine the pressure ratio between the condenser pressure ( _T12 ) and the evaporator pressure _T11 . The measured temperature _T11 in the evaporator sump 52 is currently correlated with the evaporator pressure _T11 . In addition, the measured temperature _T12 in the condenser sump 64 is currently correlated with the condenser pressure _T12 . The corresponding measured temperature reference symbols _T11 and _T12 are therefore used as reference symbols for the respective pressures in the condenser sump 64 or in the evaporator sump 52. FIG. 18 shows, for example, where the temperatures _T11 , _T12 are measured.

The cross-sectional reducing element 70 is preferably designed to assume the closed position when the pressure ratio between the condenser pressure _T12 and the evaporator pressure _T11 is greater than the maximum tolerable pressure of the first compressor stage 10, so as to guide the compressed fluid from the first compressor stage 10 through the steam channel 30 to the second compressor stage 20. When entering the second compressor stage 20, the compressed fluid is further compressed before it is supplied to the condenser 60 through the guide chamber 14. The guide chamber 14 assigned to the condenser 60 is designed similarly to the guide chamber 14 assigned to the evaporator 50 in the upper evaporator upper part 54.

Preferably, the first compressor stage 10 can be operated together with N further compressor stages, wherein N is a natural number greater than or equal to two. In FIG. 4 , three compressor stages 10 , 20 , 80 are shown, for example. According to the diagram in FIG. 4 , N is equal to three here. It is conceivable that any number of compressor stages are provided between the evaporator 50 and the condenser 60 . Preferably, the first compressor stage 10 and the N further compressor stages 80 , 30 are arranged in a series circuit, wherein two adjacent compressor stages in the N compressor stages are respectively connected via a steam channel 30 (see FIG. 4 , in which N=3 is shown, or see FIG. 5 ).

8 shows the hydraulic diagram according to FIG. 1 , in which the circuit of the indirect intercooler 8 is marked. In a preferred embodiment of the heat pump 100 , an indirect intercooler 8 is used.

In a preferred embodiment of the heat pump 100, as shown in FIG8, the heat pump 100 comprises an evaporator 50 for evaporating a fluid in order to obtain an evaporated fluid, wherein the evaporator 50 has an evaporator sump 52. In addition, the heat pump 100 comprises a condenser 60 for condensing a compressed fluid, wherein the condenser 60 has a condenser sump 64. The heat pump 100 further comprises a compressor with a first compressor stage 10 and a second compressor stage 20, wherein the compressor is arranged between the evaporator 50 and the condenser 60 along the flow direction of the evaporated fluid in the operation of the heat pump 100 and is configured to compress the evaporated fluid in order to obtain a compressed fluid. As shown in FIG8, the heat pump further comprises a container 45 for collecting an intermediate cooling fluid. In particular, the container 45 is an intermediate cooling sump 44. The heat pump further comprises a heat exchanger 82 with a pipe 56, which is designed for an intercooling fluid from a container 45 to flow through, wherein the pipe 56 is arranged in the flow region 11 between the first compressor stage 10 and the second compressor stage 20 in order to cool the vaporous fluid in the flow region 11. FIG. 8 shows, for example, that the heat exchanger 82 is arranged around the intake jacket 12 of the first compressor stage 10. In other words, according to the embodiment according to FIG. 8, the pipe 56 is arranged in the region of the first compressor stage 10. As shown in FIG. 14, the heat exchanger 82 for indirect cooling can be arranged between the first compressor stage 10 and the second compressor stage 20, in particular where the intercooler 40 and/or the further intercooler 4 and/or the further intercooler 5 can be arranged.

Preferably, the pipe 56 is metal, preferably the pipe 56 has stainless steel and/or copper. The metal pipe 56 improves the heat transfer between the fluid inside the pipe 56 and the fluid outside the pipe 56.

For example, the pipe 56 of the heat exchanger 82 is shown in Figures 8 to 10. Preferably, the pipe 56 of the heat exchanger 82 has the following area, in which the pipe 56 is extended in a spiral or spring-like manner, wherein the area extending in a spring-like or spiral manner has turns 83 with different turn spacings. In the pipe 56 extending in a spring-like manner, the diameter is constant from one turn to the next. In the pipe 56 extending in a spiral, the diameter of one turn is not the same as the diameter of the next turn. The pipe 56 extending in a spiral can be constructed as a conical spiral structure. The pipe 56 extending in a spring-like manner appears in the central projection of the spiral 101 onto a plane perpendicular to the spiral axis 102, as shown, for example, in Figure 10. Figure 10 schematically shows a heat exchanger 82.

The first compressor stage 10 preferably has an intake manifold 12 for taking in the evaporated fluid and a guide chamber 14 in order to guide the vaporous fluid into the flow region 11. The flow region 11 includes the volume of the upper evaporator part 54, the vapor channel 30 and also the crossover channel 62. The flow region 11 includes the region of the heat pump 100 into which the evaporated and compressed fluid can flow.

As shown, for example, in FIGS. 8 and 9 , the pipe 56 of the heat exchanger 82 is arranged around the intake sleeve 12 of the first compressor stage 10, wherein the turn spacing between two turns 83 in the inflow region of the steam-like fluid of the first compressor stage 10 is greater than in the outflow region of the steam-like fluid into the guide chamber 14. This can be seen, for example, in FIGS. 8 and 9 . By making the turn spacing between the two turns 83 greater in the inflow region, the flow velocity of the steam is less decelerated. In the outflow region of the steam-like fluid into the guide chamber 14, the turn spacing between the two turns 83 is greater in order to improve, in particular increase, the cooling of the steam.

11 shows, for example, a diametric perspective view of a heat exchanger 82. FIG11 shows that it is also conceivable that in the outflow region of the vaporous fluid from the guide chamber 14 the turn spacing between two turns 83 is smaller than in the inflow region.

The steam channel 30 is preferably arranged between the line 56 and the container 45 , wherein the outflow region 11 , in particular also referred to as the flow region 11 , is connected to the steam channel 30 in order to conduct the steam-like fluid through the container 45 via the steam channel 30 .

“Guided through the container 45” is to be understood as “guided over the container 45”. The vaporous fluid is drawn in by the second compressor during operation of the second compressor stage 20. As a result, the vaporous fluid is guided through the vapor channel 30, as can be seen, for example, from FIG. 8 .

Preferably, the fluid circuit channel 15 extends laterally from the outflow region 11 into the steam channel 30 in order to convey the intermediate cooling fluid flowing through the heat exchanger 82 to the container 45 via the steam channel 30 (see FIG. 8 ). The outflow region 11 extends from the outlet of the first compressor stage into the steam channel 30 and into the evaporator part 54. The fluid circuit channel 15 extends through the wall, in particular the bottom, of the upper evaporator part 54. The intermediate cooling fluid flowing through the heat exchanger 82 collects in the bottom region of the upper evaporator part 54 and forms a fluid level 51. If the fluid level 51 of the upper evaporator part 54 is located above the extension of the fluid circuit channel 15 through the wall, the intermediate cooling fluid can flow away through the fluid circuit channel 15 into the steam channel 30, in particular due to gravity.

The intake sleeve 12 preferably has a funnel shape with oppositely disposed maximum diameters 16 and minimum diameters 17, wherein the guide chamber 14 for guiding the compressed vaporous fluid extends axially to the funnel-shaped minimum diameter 17. The maximum diameter 16 can abut against the bottom of the upper evaporator part 54, whereby the intercooling fluid flowing through the heat exchanger 82 is captured outside the intake sleeve 12 of the first compressor stage 10 in the bottom region (see FIG. 8 ).

The guide chamber 14 is preferably designed to be curved at the end that transitions into the upper evaporator part 54 in order to guide the vaporous fluid flowing through the guide chamber 14 in a direction arranged opposite to the gas flow direction in the intake bushing. In particular, the vaporous fluid leaving the guide chamber 14 is guided into the steam channel 30 as long as the second compressor stage is in operation, or into the steam guide line 92 as long as the second compressor stage is not in operation.

The guide chamber 14 preferably has a volume which has a circular or elliptical base surface. The guide chamber 14 is arranged substantially perpendicularly to the smallest diameter 16 of the intake sleeve 12 of the first compressor stage 10. The guide chamber is arranged in particular in the upper evaporator part 54. Furthermore, the second compressor stage 20 also has a guide chamber 14 which is arranged substantially perpendicularly to the smallest diameter 16 of the intake sleeve 12 of the second compressor stage 20. The guide chamber 14 of the first or second compressor stage 10, 20 can also have another base surface which is arbitrarily designed.

Preferably, the further heat exchanger 82 is arranged in the steam channel 30 at a distance from the outflow region 11. Preferably, the further heat exchanger 82 is arranged in the intake bushing 12 of the second compressor stage 20. The first and second compressor stages 10, 20 are connected via the steam channel 30, wherein the steam channel 30 is arranged between the pressure side of the first compressor stage 10 and the intake side of the second compressor stage 20. Preferably, the steam channel 30 has a curved shape with a groove 32. Preferably, the container 45 is arranged in the groove 32 so that the liquid intercooling fluid flows from the steam channel 30 into the container 45. This can be seen, for example, from FIG. 8.

Preferably, the heat exchanger 82 and/or the further heat exchanger 82 has an at least partially contoured outer surface on its outer surface, which is in contact with the vaporous fluid, in order to improve the heat transfer between the heat carrier 82 and the vaporous fluid. Preferably, the heat exchanger 82 and/or the further heat exchanger 82 has an at least partially contoured inner surface on its inner surface, which is in contact with the fluid from the container 45, in order to cause the formation of turbulence at its inner surface. The contoured inner and/or outer surface can have grooves and/or embossed shapes, that is to say recesses/protrusions of any shape.

Preferably, for the self-regulation of the fluid filling state, the condenser sump 64 and/or the evaporator sump 52 and/or the container 45 are connected to each other in a fluid-conducting manner via a fluid line channel 15, so that the fluid level 51 of the individual sump 52, 45, 64 is regulated, in particular only using gravity. In other words, the fluid level 51 of the individual sump 52, 45, 64 is passively set based on the mutual geometrical arrangement and connection scheme of the individual sump 52, 45, 64 (see, for example, Figures 1, 2, 8, or Figures 12 to 14). Self-regulation currently refers to passive regulation, that is, regulation without further technical measures. However, it is conceivable that an active regulation of the fluid filling state of the sump 52, 45, 64 is also provided by a pump, wherein, for example, a control unit and a filling state sensor can be provided, which detects the filling state in the sump 52, 45, 64.

Preferably, the return line 2 is also referred to in particular as a fluid line channel 15, which extends from the condenser sump 64 into the container 45 or the intercooler sump 44 for conducting the fluid from the condenser sump 64. Furthermore, preferably, the fluid line channel 15 for conducting the fluid from the container 45 or the intercooler sump 44 extends from the container 45 or the intercooler sump 44 into the evaporator sump 52, wherein in particular the fluid line channel 15 extends from the bottom of the container 45 or the intercooler sump 44 laterally below the fluid level 51 of the evaporator sump 52 into the evaporator sump 52. Preferably, the container 45 is the intercooler sump 44 of the intercooler 40.

Preferably, the heat pump 100 has an intercooling-circulating pump 22 to deliver the intercooling fluid from the container 45 to the pipe 56. The intercooling fluid supply line 3 can extend from the container 45 to the pipe 56 in this embodiment of the heat pump 100 (see FIG. 8). In the embodiments of FIG. 12, FIG. 13 and FIG. 14, the intercooling-circulating pump 22 can deliver the intercooling fluid from the evaporator sump 52 to the pipe 56.

FIG. 9 shows a hydraulic diagram of an indirect intercooler 8 with an indirect heat transfer device 82. It can be seen from FIG. 9 in a simplified diagram that the steam channel 30 extends from the upper evaporator component 54 to the second compressor stage 20, in particular the first compressor of the first compressor stage 10 is arranged in the upper evaporator component and the heat transfer device 82 can be arranged in the upper evaporator component. The compressed fluid coming out of the first compressor stage 10 can then be guided to the second compressor stage 20 through the steam channel 30. In addition, the fluid circuit channel 15 extends from the arranged heat transfer device 82, and the fluid flowing through the heat transfer device 82 in the fluid circuit channel can be guided to the container 45. In addition, the illustration of FIG. 9 shows that the fluid circuit channel 15 and the intercooling fluid supply line 3 guide the liquid fluid, that is, water at present. In addition, it can be seen that the steam channel 30 between the first and second compressor stages 10, 20 is an activated steam path. The activated steam path currently means that the second compressor stage 20 is in operation, so that the compressed fluid leaving the first compressor stage is sucked through the second compressor stage 20. Conversely, the crossover channel 62 between the first compressor stage and the condenser 60 is an inactive steam path. An inactive steam path currently means that the second compressor stage 20 is not running and the cross-section reducing element 70 is open, so that the compressed fluid leaving the first compressor stage is directed directly into the condenser 60 via the crossover channel 62.

According to another preferred embodiment, the heat pump 100 includes an evaporator 50 for evaporating a fluid so as to obtain an evaporated fluid, wherein the evaporator 50 has an evaporator sump 52. In addition, the heat pump 100 includes a compressor with a first compressor stage 10 and a second compressor stage 20, wherein the compressor is arranged between the evaporator 50 and the condenser 60 along the flow direction of the evaporated fluid in the operation of the heat pump 100 and is configured to compress the evaporated fluid so as to obtain a compressed fluid. The condenser 60 is used to condense the compressed fluid. In addition, the heat pump 100 includes an intercooler 40, which is connected to the intercooler fluid supply line 3 and has an active element 42, wherein the active element is arranged between the first compressor stage 10 and the second compressor stage 20 and is configured to cause an interaction between the intercooler fluid that can be transported through the intercooler fluid supply line 3 and the heated steam-like fluid that can be output by the first compressor stage 10. The intercooler fluid supply line 3 extends from the evaporator sump 52 to the active element 42. Such a preferred embodiment of the heat pump is shown as a hydraulic diagram, for example, in FIG. 12. 12 further shows a hydraulic diagram from which the feed to the intercooler is derived, wherein the intercooler is fed by the evaporator sump 52. The fluid from the evaporator sump 52 is supplied to the active element 42 via the intercooler fluid supply line 3, so that the fluid from the evaporator sump 52 can be used to shower the evaporated and compressed fluid, which passes through the intercooler 40 arranged in the steam channel 30.

Preferably, the intercooling fluid supply line 3 extends through an opening in the evaporator sump 52, wherein the opening of the intercooling fluid supply line 3 is located below the fluid level 51 of the fluid in the evaporator sump 52. Fluid from the evaporator sump 52 can flow into the intercooling fluid supply line 3, in particular by utilizing gravity. In particular, the intercooling fluid supply line 3 does not require a control for conveying fluid from the evaporator sump 52. However, it is conceivable to provide a control for conveying liquid fluid to the intercooling fluid supply line 3.

12 , the intercooler 40 preferably has an intercooling sump 44, wherein, starting from the bottom of the intercooling sump, a return line 2 or a fluid line channel 15 for returning the fluid from the intercooling sump 44 to the evaporator sump 52 preferably extends laterally into the evaporator sump 52. In particular, heated vaporous fluid and intercooling fluid, which can be discharged by the first compressor stage 10, are respectively obtained from the evaporator sump 52.

Preferably, the further return line 1, which can also be referred to as a fluid line channel 15, extends directly from the condenser sump 64, preferably laterally, into the evaporator sump 52 for returning the fluid from the condenser sump 64 into the evaporator sump 52. In particular, the return line 2 and the further return line 1 are fluidically separated from one another. "Fluidically separated from one another" means that the fluids from the return line 2 and the further return line 1 cannot mix in the lines, but only mix with one another in the evaporator sump 52. With regard to lines 1, 2 and 3, FIGS. 12 and 14 show the same arrangement of lines 1, 2, 3.

FIG14 shows another preferred embodiment of a heat pump 100 as shown in FIG12. FIG14 shows a hydraulic diagram as in FIG12, from which the feed to the intercooler is derived, with an additional filling body 7 and/or additional further intercoolers 4, 5, wherein each intercooler 4, 5 is fed by the evaporator sump 52.

According to a further preferred embodiment of the heat pump, as shown in FIG14 , the intercooling fluid supply line 3 is connected to at least one further intercooler 4, 5. The further intercooler 5 can be arranged in the steam channel 30 between the evaporator 50 and the condenser 60. The further or still further intercooler 4, 5 can be arranged in particular after the outlet of the first compressor stage 10.

As shown in the embodiment according to FIGS. 12 and 14 , the intermediate cooling sump 44 is designed to collect the fluid that can flow through the intermediate cooling fluid supply line 3, wherein the fluid can be conveyed from the intermediate cooling sump 44 via the return line 2 (also referred to as fluid line channel 15) to the evaporator sump 52. In particular, the return line 2 and the further return line 1 each have an opening 55 relative to the evaporator sump 52 at a distanced position of the evaporator sump 52. In particular, the opening 55 of the further return line 1 is arranged into the evaporator sump 52 below the fluid level 51 of the evaporator sump 52. Furthermore, the opening 55 of the return line is arranged in particular into the evaporator sump 52 below the fluid level 51 of the evaporator sump 52.

An intermediate cooling fluid supply line 3 or a motor cooling line 33 from the evaporator sump 52 to the motor cooling part 34 of the first compressor stage 10 is preferably arranged to guide the fluid from the evaporator sump 52 to the motor cooling part 34 for cooling the motor M assigned to the first compressor stage 10. In particular, the intermediate cooling fluid supply line 3 and/or the motor cooling line 33 extend from the evaporator sump 52 through the motor cooling part 34 of the first compressor stage 10 to the active element 42 to guide the fluid from the evaporator sump 52 to the motor cooling part 34 for cooling the motor M assigned to the first compressor stage 10 and to the active element 42 (see Figures 12 and 14).

As can be seen from FIGS. 12 and 14 , a further motor cooling line 35 is arranged from the evaporator sump 52 to the further motor cooling 36 of the second compressor stage 20 in order to conduct fluid from the evaporator sump 52 to the further motor cooling 36 for cooling the motor M assigned to the second compressor stage 20. The motor M assigned to the compressor stage 20, 30, 80 can be cooled with the fluid from the evaporator sump 52. The fluid from the evaporator sump 52 is cooler than the fluid from the intermediate cooling sump 44. The fluid from one of the intermediate cooling sump 44 is in turn cooler than the fluid from the condenser sump 64.

As can be seen, for example, from Figures 1, 2, 8 or 12 to 15, a ball bearing adapter line 74 is preferably arranged from the intermediate cooling sump 44 to a ball bearing adapter 76 assigned to the first compressor stage 10 in order to conduct fluid from the intermediate cooling sump 44 for cooling at least one ball bearing adapter 76. In particular, a compressor cooling channel 77 is arranged from the outlet of the ball bearing adapter 76 to the first compressor stage 10 in order to conduct fluid from the ball bearing adapter 76 to the first compressor stage 10 in order to shower the compressed fluid in the first compressor stage 10 with the fluid from the ball bearing adapter 76.

Furthermore, a ball bearing adapter line 74 is preferably arranged from the condenser sump 64 to a ball bearing adapter 76 assigned to the second compressor stage 20 in order to conduct fluid from the condenser sump 64 for cooling at least one ball bearing adapter 76. In particular, a compressor cooling channel 77 is arranged from the outlet of the ball bearing adapter 76 to the second compressor stage 20 in order to conduct fluid from the ball bearing adapter 76 to the second compressor stage 20 in order to shower the compressed fluid in the second compressor stage 20 with fluid from the ball bearing adapter 76, which is assigned to the second compressor stage 20. In an embodiment not shown, the ball bearing adapter can also receive fluid for cooling from the intercooling fluid supply line 3 and thus be connected in series or in parallel to the same line, to which the motor cooling 36 is also connected.

Preferably, at least one packing body 7 is arranged in the area around the first compressor stage 10 for dissipating heat, in particular for increasing the surface and thus for optimal cooling of the steam. The at least one packing body 7 is arranged in particular around the intake sleeve 12 of the first compressor stage 10 (see FIG. 14 ). In a particularly advantageous embodiment, the at least one packing body comprises a plurality of individual packing bodies, which are distributed around the intake sleeve 12 of the first compressor stage 10.

As can be seen, for example, from FIG. 14, preferably another further intercooler 4 is arranged in the intercooling fluid supply line 3. In particular, by the arrangement of the intercooler 40, the further intercooler 4 and the further intercooler 5, the steam in the intercooling fluid supply line 3, that is to say the evaporated and compressed fluid, first passes through the further intercooler 4 after exiting the first compressor stage 10 and then passes through the further intercooler 5 and/or the intercooler 40. It is conceivable that the heat pump 100 only includes the further intercooler 4 and the further intercooler 5 (see FIG. 14). It is also conceivable that the heat pump 100 only includes the intercooler 40 (see FIG. 12). It is also conceivable that the heat pump 100 only includes the intercooler 40 and the further intercooler 4 or the further intercooler 5. In an embodiment not shown, it is also possible that the intercooler 5 extends over the entire length of the steam channel 30 and thus causes a particularly efficient cooling of the steam flowing through.

The further intercooler 4 is preferably designed as a heat exchanger 82, which is designed as a pipe 56 and/or as a tube bundle 56a and has a pipe volume through which the fluid from the evaporator sump 52 flows, in order to enable an indirect cooling 8 of the steam. FIGS. 8 to 10 show, for example, an indirect cooling 8 achieved by means of a heat exchanger 82. The heat exchanger 82 has already been discussed in detail, to which reference is made here.

Preferably, the second compressor stage 20 is arranged between the evaporator 50 and the condenser 60, and the intercooler 40, the further intercooler 4 and/or the further intercooler 5 are arranged at a distance from the intake region of the second compressor stage 20. As can be seen, for example, in FIG. 14 , the intercooler 40 and/or the further intercooler 4 and/or the further intercooler 5 can be arranged in the upper evaporator part 54 and/or starting from the first compressor stage 10 in the steam channel 30 up to the groove 32.

In order to adjust the fluid filling state, i.e. the fluid level 51, the condenser sump 64 and/or the evaporator sump 52 and/or the intermediate cooling sump 44 can each have a level adjustment. Preferably, the level adjustment can be abandoned as long as the fluid level 51 in each sump 52, 44, 64 is controlled individually by the height of the outflow, that is to say as long as self-regulation (as described) can be achieved. Then there is no need to actively adjust the fluid level 51. The outflow currently refers to, for example, the opening 65 of the steam guide line 92 to the condenser 60, and/or the opening 65 of the return line 2 to the intermediate cooling sump 44, and/or the opening 65 of the intermediate cooling fluid supply line 3 to the evaporator sump 52, as shown, for example, in Figures 12, 13 and 14.

As already explained, FIG. 15 shows a compressor characteristic diagram 170 of an N-stage compressor, wherein the compressor characteristic diagram 170 specifies the relationship between the pressure ratio and the mass flow.

FIG. 16 shows a three-dimensional envelope surface 180 for the corrected mass flow, wherein the dotted line shows the measured speed characteristic curve 181. The speed characteristic curve 181 depends on the corrected mass flow WCcorr and the compression ratio PiC. In FIG. 16, the pump limit 171 according to the corrected mass flow and the compressor ratio is marked, similar to FIG. 15. The envelope surface 180 is shown as a compensation surface (3D-Fit, i.e.: 3D-fit), which is adapted to the measured speed characteristic curve 181. The envelope surface 180 first rises with the rising corrected mass flow and the rising speed, and is reflected by a three-dimensionally monotonically rising function. After reaching a mass flow of approximately 0.8, the envelope surface 180 shows a monotonically decreasing trend.

17 shows a three-dimensional diagram for determining the volume flow for determining the corrected mass flow. The volume flow is given by a function that depends on the electrical power _Pe1 obtained and the rotational speed of the compressor stages 10, 20. Preferably, compressor stages 10, 20 of identical construction are used in the heat pump 100. It is conceivable to use compressor stages 10, 20 that differ from each other.

The volume flow cannot be measured directly. Instead, it is determined indirectly via a stored 3D characteristic diagram 190, which is specific to the compressor drive used. The volume flow is derived from the consumed electrical power _Pe1 and the rotational speed of the compressor drive by means of the 3D characteristic diagram in the 3D characteristic diagram 190 (see dotted curve 191), wherein the measured values 191 are plotted in the 3D characteristic diagram 190. After the volume flow is determined, the mass flow can be corrected, in particular by using knowledge of the molar mass of the fluid at a given pressure and a given temperature.

According to a preferred embodiment, the heat pump 100 includes: an evaporator 50 for evaporating a fluid to obtain an evaporated fluid; a condenser 60 for condensing a compressed fluid; and a compressor having a first compressor stage 10 and a second compressor stage 20, wherein the compressor is arranged between the evaporator 50 and the condenser 60 along the flow direction of the evaporated fluid during operation of the heat pump 100 and is configured to compress the evaporated fluid to obtain a compressed fluid. In addition, the heat pump 100 includes a value detection device 95 for detecting a first value P1, which corresponds to a first pressure ratio between an inlet of the first compressor stage 10 and an outlet of the first compressor stage 10 or depends on the first pressure ratio; and a control unit 96 for controlling a first rotation speed of the first compressor stage 10 and a second rotation speed of the second compressor stage 20, wherein the control unit 96 is configured to control the second rotation speed of the second compressor stage 20 according to the first value P1. The value detection device 95 and the control unit 96 can communicate with each other and can communicate with components of the heat pump 100 respectively, as indicated by arrows in opposite directions in FIG. 18. The outlet of the first compressor stage 10 includes the region immediately after the first compressor stage 10 and also the region between the first compressor stage 10 and the second compressor stage 20 , in particular the region in the steam channel 30 .

Preferably, the value detection device 95 is designed to detect a second value P2, which corresponds to a second pressure ratio between the outlet of the second compressor stage 20 and the inlet of the first compressor stage 10 or depends on the second pressure ratio, and wherein the control unit 96 is designed to control the second speed in addition as a function of the second value P2. In particular, the region of the inlet of the second compressor stage 20 can be connected to the region of the outlet of the first compressor stage 10. For example, the region of the outlet of the first compressor stage 10 can end in the groove 32 and the region of the inlet of the second compressor stage 20 can begin in the groove 32 of the steam channel 30 (see FIG. 18).

FIG. 18 shows a hydraulic diagram of a heat pump 100, in which a first temperature sensor 91, a second temperature sensor 92 and a third temperature sensor 93 are marked. In addition, FIG. 18 shows a control unit 96 and a numerical detection device 95, which communicate with each component of the heat pump 100 and also communicate with each other. The coolant 97 gives the cold water temperature, and the user of the heat pump 100 uses the cold water temperature as the actual temperature for use. The first temperature sensor 91 measures the first temperature Tl1 in the evaporator sump 52 and therefore before the first compressor stage 10. The second temperature sensor 92 measures the second temperature Tl3 in the intermediate cooling sump 44 and therefore after the first compressor stage 10 and before the second compressor stage 20. The third temperature sensor 93 measures the third temperature Tl2 in the condenser sump 64 and therefore after the second compressor stage. As FIG. 18 points out, the refrigeration power 103 is available to the user, and the refrigeration power is used as power to cool the user water. This relates to the power provided to the user or the user. The derived thermal power 105 is the thermal power derived by the reflux cooler. The motors M of the compressor stages 10, 20 consume electrical power 104, which is the power consumed by the heat pump 100, which is consumed by the two compressor stages 10, 20. For example, the maximum pressure ratio of the first compressor stage 10 can be P1=3.7. For example, the maximum pressure ratio of the second compressor stage 20 can be P2=3.7. In this case, for example, the maximum total pressure ratio P _ges of the heat pump 100 can be P _ges =P1*P2=3.7*3.7=13.7. In addition, it can be concluded in conjunction with Figure 19 that in case 1, the first compressor stage 10 is constantly operated at a pressure ratio of, for example, P1=2.7, and the second compressor stage 20 is operated at a pressure ratio P2 between zero and 2.7. When the first compressor stage 10 and the second compressor stage 20 are respectively operated at a pressure ratio of P1=P2=2.7, the heat pump 100 switches from the situation (first power range 98) to the situation 2 (second power range 99). In the second power range 99 , the compression ratios of the first compressor stage 10 and the second compressor stage 20 are each increased uniformly from P1 = P2 = 2.7 to P1 = P2 = 3.7.

Preferably, the control unit 96 is configured to use the first value P1 as an actual value and the second value P2 as a target value. In addition, the control unit 96 is preferably configured to increase the rotational speed of the second compressor stage 20 when the actual value is greater than the target value, or to reduce the rotational speed of the second compressor stage 20 when the actual value is less than the target value. By comparing the actual value and the target value, the rotational speed of the first and second compressor stages 10, 20 can be set in such a way that the second compressor stage can be used efficiently independently of the first compressor stage 10. Independent setting of the rotational speed of the first and second compressor stages 10, 20 is achieved in that each motor M of the compressor stage 10, 20 has its own motor shaft to be driven. According to P1=Tl3/Tl1, the first value P1 gives the compression ratio of the first compressor stage 10. According to P2=Tl2/Tl3, the second value P2 gives the compression ratio of the second compressor stage 20.

Preferably, the value detection device 95 is further configured to determine the actual temperature of the coolant 97 discharged on the evaporator side, and the control unit 96 is configured to set the rotational speed of the first compressor stage 10 as a function of the actual temperature of the coolant 97 and a predefined target temperature of the coolant 97. During operation of the heat pump 100, the heat pump can increase the actual temperature of the coolant 97 discharged on the evaporator side, because the operation of the heat pump 100 causes the fluid circulating in the heat pump, that is, the coolant 97, to have a higher temperature over time.

The control unit is preferably constructed to operate the first compressor stage 10 at a higher pressure ratio than the second compressor stage 20 in dependence on the power requirement in the first power range 98, wherein the difference in the pressure ratios of the first compressor stage 10 and the second compressor stage 20 decreases relative to the increased power requirement (see case 1 in Figure 19); and in the second power range 99, both the first compressor stage 10 and the second compressor stage 20 are operated in such a way that the pressure ratios of the two compressor stages 10, 20 in the second power range 99 are approximately equal, or in particular equal within a range of plus/minus 20 percent, and/or increase identically in the case of increased power requirement (see case 2 in Figure 19), wherein the second power range 99 includes a power requirement that is greater than the first power range 98, wherein the boundary 94 between the first power range 98 and the second power range 99 is determined by the first compressor stage 10 and/or by the second compressor stage 20. FIG. 19 shows a diagram for illustrating the regulation of the compressor stages 10, 20 of a heat pump 100 according to the rotational speed of the first and second compressor stages 10, 20 in a first power range 98 and in a second power range 99. In case 2, i.e., in the second power range 99, a higher power π is implemented than in the first case, i.e., in the first power range 98 (see FIG. 19). In addition, it can be seen from FIG. 19 that the first compressor stage 10 operates at a constant power value, in particular π=2.7. The constant power value π of the first compressor stage 10 corresponds to the target value in the first power range 98, in which the first compressor stage should be operated. The second compressor stage 20 starts with a lower power π at first, but gradually approaches the target value of the first power stage 10. If the second compressor stage 20 also reaches the target value of the power π, then the two compressor stages 10, 20 are switched to operation corresponding to case two, i.e., in the second power range 99. In the second power range, the pressure ratio of the first compressor stage 10 and the second compressor stage 20 preferably increases uniformly. At the boundary 94, the operation in the first power range 98 is switched to the operation in the second power range 99. In particular, the heat pump 100 switches from the operation in the first power range 98 to the operation in the second power range 99 at a total pressure ratio of (ρ(Tl2)/ρ(Tl1)) ^1/2 , wherein ρ(Tl1) represents the saturated vapor pressure in the evaporator sump 52, which can be measured in particular by the first temperature sensor 91, and wherein ρ(Tl2) represents the saturated vapor pressure in the condenser sump 64, which can be measured in particular by the third temperature sensor 93 (see FIG. 18 ).

Preferably, the first compressor stage 10 and the second compressor stage 20 have radial wheels of different sizes, wherein the control unit 96 is designed to control the first compressor stage 10 to a constant first pressure ratio as a target value in a first power range 98, and to control the second compressor stage 20 to an increased second pressure ratio as a target value in the case of an increased power requirement, and to accommodate the increased power requirement in a second power range 99 not only by the first compressor stage 10 but also by the second compressor stage 20 (see FIG. 19 ). For example, in the compressor stages 10, 20 used, the target value is about 2.7, as already described. When using other compressor stages, the target value can be different. In particular, the target value is specific to the compressor. Preferably, the radial wheel of the first compressor stage 10 is designed to be larger than the radial wheel of the second compressor stage 20. In particular, the two radial wheels are designed so that they both carry out approximately the same mass flow. Since the temperature is higher in front of the second radial wheel, that is, the radial wheel of the second compressor stage 20, than in front of the first radial wheel, that is, the radial wheel of the first compressor stage 10, the second radial wheel must be made smaller.

The control unit 96 is preferably configured to use the maximum value of a function consisting of the second value P2 or a predefined constant value konst. as a target value for controlling the second speed of the second compressor stage 20. The predefined constant value depends on the compressor used and is preferably in the range between 1 and 5, that is, 1≤konst.≤5, and is also preferably in the range between 2 and 4, with the constant value konst=2.7 being particularly advantageous. The constant value is the optimal pressure ratio of the first compressor. Therefore, by:

Maximum value = P2 or konst.

to give a maximum value of the second rotational speed of the second compressor stage 20 .

The maximum value is given by a maximum function which is the maximum value from the second value P2 or a predefined constant value konst.

Preferably, the maximum function is a root function and the predefined constant value is the boundary 94 between the first and second power ranges 98, 99. The maximum function is in particular given by (ρ(Tl2)/ρ(Tl1)) ^1/2 , wherein ρ(Tl1) denotes the saturated vapor pressure in the evaporator sump (52), which can be measured in particular by the first temperature sensor 91, and wherein ρ(Tl2) denotes the saturated vapor pressure in the condenser sump 64, which can be measured in particular by the third temperature sensor 93 (see FIG. 18).

The first value P1 is given by the ratio P1=T13/T11. The second value P2 is given by the ratio P2=T12/T13.

As indicated in FIG19 , the overall compression ratio P _ges is given by the product of the first value P1 and the second value P2, i.e., by P _ges = P1 * P2 = (Tl3 / Tl1) * (Tl2 / Tl3) = Tl2 / Tl1. As can be seen, for example, from FIG19 , the first value P1 and the second value P2 are added geometrically (thus 2 * α / 2 = α) to obtain the overall compression ratio P _ges .

Preferably, the value detection device 95 includes a first temperature sensor for detecting a first temperature Tl1 about the evaporator 50, and a second temperature sensor for detecting a second temperature Tl3 about the outlet of the first compressor stage 10, wherein the value detection device 95 is configured to determine the first value P1 from the first temperature Tl1 and the second temperature Tl3. FIG. 18 shows, for example, where the temperature sensors can be arranged in the hydraulic diagram of the heat pump 100, indicating where which of the temperatures Tl1, Tl2 and Tl3 can be measured.

Preferably, a first temperature sensor is arranged in the evaporator sump 52 of the evaporator 50 to detect a first temperature Tl1 before the first compressor stage 10, and a second temperature sensor is arranged in the intercooling sump 44 to detect a second temperature Tl3 after the outlet of the first compressor 10. Preferably, the outlet of the first compressor 10 includes a groove 32 in the steam channel 30, which fluidly connects the first compressor stage 10 and the second compressor stage 20.

Preferably, a steam channel 30 is provided between the first compressor stage 10 and the second compressor stage 20 in order to conduct the compressed fluid from the first compressor stage 10 to the second compressor stage 20, wherein an intermediate cooling sump 44 or a container 45 is arranged in the steam channel 30. The first compressor stage 10 and the second compressor stage 20 are connected to each other in a fluidic manner via the steam channel 30.

As can be seen from FIG. 18 , the value detection device 95 comprises a third temperature sensor in order to measure the third temperature Tl2, wherein the value detection device 95 is configured to determine the second value P2 from the third temperature Tl2 and the first temperature (T11). Preferably, the third temperature sensor is arranged in the condenser sump 64 in order to detect the third temperature Tl2 after the second compressor stage 20. FIG. 18 shows a hydraulic diagram that highlights the temperature sensor for guiding the second compressor, in particular where the temperature sensor can be arranged in the heat pump 100 in order to measure the corresponding temperature Tl1, Tl2 or Tl3. As shown, for example, in FIG. 8 , as an alternative to being arranged in the intermediate cooling sump 44, the second temperature sensor can also be arranged in the container 45, that is, in the sump 44, 45, which fluidically connects the first compressor stage 10 and the second compressor stage to each other in a fluidic manner.

Preferably, the fluid circuit channel 15 extends from the condenser sump 64 into the intermediate cooling sump 44 (FIG. 18) or into the container 45 (FIG. 8) in order to conduct the fluid from the condenser sump 64 into the intermediate cooling sump 44 or into the container 45, and further fluid circuit channels 15 extend from the intermediate cooling sump 44 or into the container 45 into the evaporator sump 52 in order to conduct the fluid from the intermediate cooling sump 44 or into the container 45 into the evaporator sump 52. By connecting the sumps 64, 44, 45 and 52 to one another via the fluid circuit 15, the fluid in each of the sumps 64, 44, 45 and 52 is increased during the operation of the heat pump 100. This can already lead to the need to adjust the compressor stages of the heat pump due to the operating time of the operation of the heat pump 100, as shown in FIG. 19.

Preferably, a crossover channel 62 is arranged between the first compressor stage 10 and the condensing machine 60 in order to crossover the second compressor stage 20, wherein a cross-section reducing element 70 is arranged in the crossover channel 62 in order to set the cross-section of the crossover channel 62 in order to adjust the flow of compressed fluid from the first compressor stage 10 to the condensing machine 60, wherein the cross-section reducing element 70 assumes a closed position when the second compressor stage 20 is in operation. The crossover channel 62 and the cross-section reducing element 70 have already been described in detail, to which reference is made.

The speed of compressor stage 10, 20 can be increased for two reasons, because not only the user side but also the reflux cooler side also affects the heat pump. For example, the cold water temperature 97 can rise. The water provided to the user by the user has a higher temperature, that is to say, the user needs a larger refrigeration power. In this case, the speed of the first compressor stage 10 is increased, thereby supplying a larger electrical power 104 to the heat pump 100. The refrigeration power 103 generated by the heat pump is increased. In another case, when the water temperature from the reflux cooler to the liquefier increases, for example, when the external temperature increases and the reflux cooler can only discharge heat energy with a larger energy consumption, the cold water temperature 97 can rise. In this case, for example, the measured temperatures Tl1, Tl3 and Tl2 rise, thereby finally causing the cold water temperature reaching the user to rise. For the operation of compressor stage 10, 20, this means that first the first compressor stage is increased in terms of its speed and in a time-shifted manner (zweitversetzt) and then the second compressor stage is also increased in terms of its speed. In the event of an increase in the cooling water temperature, the consumed electrical power 104 of the heat pump 100 also increases accordingly.

The heat pump described here can utilize the second compressor more efficiently, thereby making it possible to utilize the heat pump itself more efficiently. In addition, it is prevented that the second compressor stage is operated at the pump limit or at the absorption limit.

In particular, the first compressor stage provides the user with the required refrigeration power. The second compressor stage 20 discharges heat from the heat pump 100 to the reflux cooler. When the first compressor stage 10 provides a greater refrigeration power for the user, more heat power is output to the reflux cooler through the compressor stage 20, thereby increasing the electrical power consumed by the heat pump.

Another aspect relates to a method for operating a heat pump 100, which has: an evaporator 50 for evaporating a fluid so as to obtain an evaporated fluid, wherein the evaporator 50 has an evaporator sump 52; a condenser 60 for condensing the evaporated fluid compressed by an N-stage compressor, wherein the condenser 60 has a condenser sump 64, a condensation area 66 and a holding area 67, wherein the holding area is used to hold the vapor-like fluid remaining after the condensation area 66; an N-stage compressor, wherein the N-stage compressor includes N compressors, wherein N is a natural number greater than or equal to one, wherein the N-stage compressor is arranged between the evaporator 50 and the condenser 60; a steam channel 30, which is connected to the N compressors of the N-stage compressor At least two compressors are coupled between the evaporator 50 and the condenser 60; and a steam guiding line 92 is arranged between the condenser 60 and the evaporator 50 so as to guide the vapor-like fluid from the holding area 67 of the condenser 60 to the evaporator 50. The method comprises the following steps: evaporating the fluid through the evaporator 50; conveying the evaporated fluid to the first compressor stage 10 so as to compress the evaporated fluid, guiding the compressed fluid through the steam channel 30 so as to pass through N compressors; so as to finally reach the condenser 60; condensing the compressed fluid in the condensation area 66 and maintaining the uncondensed fluid in the holding area 67; and returning the evaporated fluid from the holding area 67 to the evaporator 50 through the steam guiding line 92.

Another aspect relates to a method for manufacturing a heat pump 100, which has: an evaporator 50 for evaporating a fluid so as to obtain an evaporated fluid, wherein the evaporator 50 has an evaporator sump 52; a condenser 60 for condensing the evaporated fluid compressed by an N-stage compressor, wherein the condenser 60 has a condenser sump 64, a condensation area 66 and a holding area 67, and the holding area is used to hold the vapor-like fluid remaining after the condensation area 66; an N-stage compressor, wherein the N-stage compressor includes N compressors, wherein N is a natural number greater than or equal to one, wherein the N-stage compressor is arranged between the evaporator 50 and the condenser 60. The method comprises the following steps: arranging the evaporator 50, the N-stage compressor and the condenser 60; connecting the evaporator, the N-stage compressor and the condenser 60 through the steam channel 30; and connecting the evaporator and the condenser 60 through the steam guide line 92 so as to establish a loop in which the fluid circulates.

Another aspect relates to a method for operating a heat pump 100, which has: an evaporator 50 for evaporating a fluid in order to obtain an evaporated fluid, wherein the evaporator 50 has an evaporator sump 52; a condenser 60 for condensing a compressed fluid, wherein the condenser 60 has a condenser sump 64; a compressor, which has a first compressor stage 10 and a second compressor stage 20, wherein the compressor is arranged between the evaporator 50 and the condenser 60 along the flow direction of the evaporated fluid during operation of the heat pump 100, and is constructed to compress the evaporated fluid in order to obtain a compressed fluid; wherein the method includes the steps of: collecting an intermediate cooling fluid in a container 45; and flowing the intermediate cooling fluid from the container 45 through a pipe 56 through a heat exchanger 82, wherein the pipe 56 is arranged in a flow region 11 between the first compressor stage 10 and the second compressor stage 20 in order to cool the vaporous fluid in the flow region 11.

Another aspect relates to a method for manufacturing a heat pump 100, which has: an evaporator 50 for evaporating a fluid so as to obtain an evaporated fluid, wherein the evaporator 50 has an evaporator sump 52; a condenser 60 for condensing a compressed fluid, wherein the condenser 60 has a condenser sump 64; a compressor having a first compressor stage 10 and a second compressor stage 20, wherein the method includes: arranging the compressor along the flow direction of the evaporated fluid so that during operation of the heat pump 100, the compressor is arranged between the evaporator 50 and the condenser 60 so as to compress the evaporated fluid so as to obtain a compressed fluid; arranging a container 45 for collecting an intermediate cooling fluid; and arranging a heat exchanger 82, which has a pipe 56 between the first compressor stage 10 and the second compressor stage 20 in the flow area 11, so that during operation of the heat pump, the intermediate cooling fluid from the container 45 flows through the pipe 56 and so as to cool the vaporous fluid in the flow area 11.

Another aspect relates to a method for operating a heat pump 100, which has: an evaporator 50 for evaporating a fluid in order to obtain an evaporated fluid, wherein the evaporator 50 has an evaporator sump 52; a compressor having a first compressor stage 10 and a second compressor stage 20, wherein the compressor is arranged between the evaporator 50 and a condenser 60 along the flow direction of the evaporated fluid during operation of the heat pump 100 and is configured to compress the evaporated fluid in order to obtain a compressed fluid; and a condenser 60 for condensing the compressed fluid; and an intercooler 40, which The intercooler is connected to an intercooling fluid supply line 3 and has an active element 42, wherein the active element 42 is arranged between the first compressor stage 10 and the second compressor stage 20, wherein the method comprises: conveying the intercooling fluid from the evaporator sump 52 to the active element 42 through the intercooling fluid supply line 3; outputting the heated vapor-like fluid through the first compressor stage 10; and enabling the intercooling fluid conveyed through the intercooling fluid supply line 3 to interact with the heated vapor-like fluid output by the first compressor stage 10 so as to cool the vapor-like fluid.

Another aspect relates to a method for manufacturing a heat pump 100, which has: an evaporator 50 for evaporating a fluid so as to obtain an evaporated fluid, wherein the evaporator 50 has an evaporator sump 52; a compressor having a first compressor stage 10 and a second compressor stage 20, wherein the compressor is arranged between the evaporator 50 and a condenser 60 along the flow direction of the evaporated fluid during operation of the heat pump 100 and is constructed to compress the evaporated fluid so as to obtain a compressed fluid; and a condenser 60 for condensing the compressed fluid; wherein the method includes: arranging an intercooler 40 having an active element 42, which is between the first compressor stage 10 and the second compressor stage 20; connecting the intercooler 40 to an intercooling fluid supply line 3, which extends from the evaporator sump 52 to the active element 42, so as to cause an interaction between the intercooling fluid that can be conveyed through the intercooling fluid supply line 3 and the heated vapor-like fluid that can be output by the first compressor stage 10 during operation of the heat pump 100.

Another aspect relates to a method for operating a heat pump 100, which has: an evaporator 50 for evaporating a fluid so as to obtain an evaporated fluid; a condenser 60 for condensing a compressed fluid; a compressor having a first compressor stage 10 and a second compressor stage 20, wherein the compressor is arranged between the evaporator 50 and the condenser 60 along the flow direction of the evaporated fluid during operation of the heat pump 100, and is constructed to compress the evaporated fluid so as to obtain a compressed fluid; and a cross-over channel 62 between the first compressor stage 10 and the condenser 60, wherein the method includes: cross-over the second compressor stage 20 by setting the cross-section of a cross-section reducing element 70 in the cross-over channel 62 so as to adjust the flow rate of the compressed fluid from the first compressor stage 10 to the condenser 60.

Another aspect relates to a method for manufacturing a heat pump 100, which has: an evaporator 50 for evaporating a fluid so as to obtain an evaporated fluid; a condenser 60 for condensing a compressed fluid; a compressor having a first compressor stage 10 and a second compressor stage 20, wherein the compressor is arranged between the evaporator 50 and the condenser 60 along the flow direction of the evaporated fluid during operation of the heat pump 100, and is constructed to compress the evaporated fluid so as to obtain a compressed fluid; wherein the method includes: arranging a cross-over channel 62 between the first compressor stage 10 and the condenser 60 so as to bridge the second compressor stage 20, arranging a cross-section reducing element 70 in the cross-over channel 62 so as to set the cross-section of the cross-over channel 62 so as to adjust the flow rate of the compressed fluid from the first compressor stage 10 to the condenser 60.

Another aspect relates to a method for operating a heat pump 100, which has: an evaporator 50 for evaporating a fluid so as to obtain an evaporated fluid; a condenser 60 for condensing a compressed fluid; and a compressor having a first compressor stage 10 and a second compressor stage 20, wherein the compressor is arranged between the evaporator 50 and the condenser 60 along the flow direction of the evaporated fluid during operation of the heat pump 100, and is constructed to compress the evaporated fluid so as to obtain a compressed fluid, the method having the following steps: detecting a first value P1, which corresponds to a first pressure ratio between an inlet of the first compressor stage and an outlet of the first compressor stage or depends on the first pressure ratio; and controlling a first rotational speed of the first compressor stage 10 and a second rotational speed of the second compressor stage 20, wherein the second rotational speed of the second compressor stage 20 is controlled according to the first value P1.

Another aspect relates to a method for manufacturing a heat pump 100, which has: an evaporator 50 for evaporating a fluid so as to obtain an evaporated fluid; a condenser 60 for condensing a compressed fluid; and a compressor having a first compressor stage 10 and a second compressor stage 20, the method having the following steps: arranging the compressor between the evaporator 50 and the condenser 60 along the flow direction of the evaporated fluid during operation of the heat pump 100 so as to compress the evaporated fluid so as to obtain a compressed fluid; and connecting a numerical detection device to the compressor, the evaporator or the condenser, the numerical detection device being used to detect a first value, which corresponds to a first pressure ratio between an inlet of the first compressor stage and an outlet of the first compressor stage or depends on the first pressure ratio; and connecting a control unit for controlling a first rotational speed of the first compressor stage 10 and a second rotational speed of the second compressor stage 20 to the compressor, wherein the second rotational speed of the second compressor stage 20 is controlled according to the first value.

As already mentioned in the general part, the various aspects described with respect to the heat pump can also be implemented as method steps.

Preferably, as described above, by matching the individual features and combining the individual features into one of the heat pumps 100 described above, a method for manufacturing a heat pump 100 can be provided. The individual features will not be discussed again in conjunction with the method for manufacturing a heat pump at this time. Rather, reference is made here to the above description of the individual features, which description can also be understood as method steps for manufacturing.

In addition, the method for operating the heat pump 100 preferably first includes providing the heat pump 100, as described above. In order to operate the heat pump, at least one compressor stage, especially the first compressor stage 10, is operated. During the operation of the first compressor stage 10, the fluid is evaporated by the evaporator 50 and then supplied to the first compressor stage. At the same time, the liquid fluid is supplied to the active element 42 and/or the heat transfer device 82 through the intermediate cooling fluid supply line 3. As described above, the evaporated and compressed fluid leaving the first compressor stage 10 is cooled. In addition, the method for operating the heat pump 100 includes: setting the cross-sectional reduction element 70 to an open position, a closed position or to an intermediate position, as described above. Depending on the position of the cross-sectional reduction element 70, the evaporated and compressed fluid leaving the first compressor stage 10 is either directly guided to the condenser 60 (unactivated steam path) through the crossover channel 62 and/or guided to the second compressor stage 20 (activated steam path) through the steam channel 30. In the intermediate position of the cross-section reducing element 70, the inactive steam path and the active steam path can be used in particular for guiding the evaporated and compressed fluid. The description of the circulation of the fluid is already obtained from the above description, which will not be repeated in conjunction with the method for operating a heat pump in order to avoid redundancy. Rather, reference is also made here to the above description, which can also be understood as method steps for operating a heat pump.

The different described features can be combined with one another or replaced with one another in particular. In particular, fluid and cooling water are used synonymously with respect to one another. In particular, when the word "steam" is used, it refers to the evaporated fluid.

List of reference numerals:

1 Additional return line

3Intermediate cooling fluid supply lines

2-circuit lead line

4 Additional intercoolers

5Another intercooler

7 Filling body

8Indirect intercooling

10First compressor stage

11Flow Area

12 suction sleeve

14 Orientation Room

15 fluid line channels

16 Maximum diameter

17Minimum diameter

20 Second compressor stage

22 Circulation pump

30 Steam channel (banana structure)

32 grooves

33 Motor cooling circuit

34 Motor cooling unit

35 Additional motor cooling circuit

36 Additional motor cooling unit

40 Intercooler

42 Action elements

44 Intermediate cooling tank

45 containers

46 First intercooler line

48 Second intercooler circuit

49 ball bearing adapter

50 Evaporator

51 Fluid Level

52 Evaporator sump

54 Evaporator components above

55 towards the opening in the evaporator

56 Pipeline

56a Tube

56b Spiral pipe arrangement structure

57 Wet Area

58 Wet Equipment

59 first evaporator line

60 condensing machine

62 Crossover Channels

64 Condenser tank

65 Opening of the line towards the pot

66 Condensation Area

67 Keep Area

68 Filling Status

70 Cross-section reducing element

72 Cross-sectional reduction element diameter

74 Ball Bearing Adapter Line

76 ball bearing adapter

77 Compressor cooling channel

80Nth compressor stage

82 heat transfer device

83 turns

90 Steam transfer flap/bridge flap

92 Steam guide line

91 First Temperature Sensor

92 Second temperature sensor

93 Third temperature sensor

94 Border

95 numerical detection device

96 Control Department

97 Actual temperature of the coolant output on the evaporator side

98 First Power Range

99 second power range

Tl1 first temperature

Tl3 Second temperature

Tl2 third temperature

100 heat pumps

101 spiral

102 spiral axis

103 Refrigeration power

104 Electric power

105 Power Discharge

170 Compressor characteristic curve family/boundary line

171 Pump Limit

172 dotted line

180 Envelope Surface

181 Speed characteristic curve

P1 first value/actual value

P2 second value/target value

M Motor

300 test bench

301 Compressors to be tested

302 Pressure Sensor

303 Temperature Sensor

304 steam flow structure

306 pipeline

307 throttle valve

308 Reflux Department

309 Sensor

310 Pump

311 connector

2′ evaporator

3′ First compressor

4′ Intermediate cooling section

4a′ Intermediate cooling tank

4c′ pump

5′ Second compressor

6′ condenser

41′ container

71′ input line

72′ input line

V0 Steam Bypass

50′ evaporator

60' condensing unit.

Claims (14)

1. A heat pump (100) having the following features:

an evaporator (50) for evaporating a fluid in order to obtain an evaporated fluid, wherein the evaporator (50) has an evaporator bottom sump (52);

-a compressor having a first compressor stage (10) and a second compressor stage (20), wherein the compressor is arranged between the evaporator (50) and a condenser (60) along a flow direction of the evaporated fluid in operation of the heat pump (100) and is configured for compressing the evaporated fluid in order to obtain a compressed fluid; and

A condenser (60) for condensing the compressed fluid; and

-An intercooler (40) connected to an intercooler fluid supply line (3) and having an active element (42), wherein the active element (42) is arranged between the first compressor stage (10) and the second compressor stage (20) and is configured for causing an interaction between an intercooler fluid that can be conveyed via the intercooler fluid supply line (3) and a heated vaporous fluid that can be output by the first compressor stage (10), and wherein the intercooler fluid supply line (3) extends from the evaporator sump (52) to the active element (42).

2. The heat pump (100) according to claim 1, wherein the intermediate cooling fluid supply line (3) extends through an opening (55) in the evaporator bottom sump (52), and wherein the opening (55) of the intermediate cooling fluid supply line (3) is located below a fluid level (51) of the fluid in the evaporator bottom sump (52).

3. Heat pump (100) according to claim 1 or 2, wherein the intercooler (40) has an intermediate cooling bottom sump (44), wherein, starting from the bottom of the intermediate cooling bottom sump (44), a return line (2) for returning fluid from the intermediate cooling bottom sump (44) into an evaporator bottom sump (52) extends preferably laterally into the evaporator bottom sump (52), in particular wherein a heated vaporous fluid which can be output by the first compressor stage (10) and the intermediate cooling fluid are each taken out of the evaporator bottom sump (52).

4. A heat pump (100) according to any one of claims 1 to 3, wherein a further return line (1) for returning fluid from the condenser bottom sump (64) into the evaporator bottom sump (52) extends from the condenser bottom sump (64) directly, preferably laterally, into the evaporator bottom sump (52), in particular wherein the return line (2) and the further return line (1) are fluidly separated from each other.

5. The heat pump (100) according to any one of claims 1 to 4, wherein the inter-cooling fluid supply line (3) is furthermore connected with at least one further inter-cooler (4), wherein the further inter-cooler (4) is arranged in a steam channel (30) between the evaporator (50) and the condenser (60), in particular wherein the further inter-cooler (4) is arranged after the outlet of the first compressor stage (10).

6. The heat pump (100) according to any one of claims 3 to 5, wherein the intermediate cooling bottom tank (44) is configured for collecting fluid flowable through the intermediate cooling fluid supply line (3), wherein the fluid can be conveyed from the intermediate cooling bottom tank (44) to an evaporator bottom tank (52) by the return line (2), in particular wherein the return line (2) and the further return line (1) each have openings (55) at spaced apart positions relative to the evaporator bottom tank (52) with respect to the evaporator bottom tank (52).

7. The heat pump (100) according to any one of the preceding claims, wherein the intermediate cooling fluid supply line (3) or a motor cooling line (33) from the evaporator sump (52) to the motor cooling (34) of the first compressor stage (10) is arranged for guiding fluid from the evaporator sump (52) to the motor cooling (34) for cooling the motor (M) associated with the first compressor stage (10), in particular wherein the intermediate cooling fluid supply line (3) or the motor cooling line (34) extends from the evaporator sump (52) through the motor cooling (34) of the first compressor stage (10) to the active element (42) for guiding fluid from the evaporator sump (52) to the motor cooling (34) for cooling the motor (M) associated with the first compressor stage (10) and to the active element (42).

8. The heat pump (100) according to any of the preceding claims, wherein a further motor cooling circuit (35) is arranged from the evaporator bottom sump (52) to a further motor cooling (36) of the second compressor stage (20) for guiding fluid from the evaporator bottom sump (52) to the further motor cooling (36) for cooling the motor (M) associated with the second compressor stage (20).

9. The heat pump (100) according to any of the preceding claims, wherein a ball bearing adapter line (74) is arranged from the intermediate cooling bottom pool (44) to a ball bearing adapter (74) assigned to a first compressor stage (10) for guiding fluid from the intermediate cooling bottom pool (44) for cooling at least one ball bearing adapter (74), in particular wherein a compressor cooling channel (77) is arranged from an outlet of the ball bearing adapter (74) to the first compressor stage (10) for guiding fluid from the ball bearing adapter (74) to the first compressor stage (10) for showering compressed fluid in the first compressor stage (10) with fluid from the ball bearing adapter (74).

10. The heat pump (100) according to any of the preceding claims, wherein at least one filling body (7) for discharging heat is arranged in a region surrounding the first compressor stage (10).

11. The heat pump (100) according to any one of the preceding claims, wherein a further intercooler (5) is arranged in the intercooler fluid supply line (3), in particular wherein by arranging the intercooler (40), the further intercooler (4) and the further intercooler (5) the steam in the intercooler fluid supply line (3) after exiting the first compressor stage (10) passes first through the further intercooler (4) and then through the further intercooler (5) and/or the intercooler (40).

12. The heat pump (100) according to any one of the preceding claims 5 or 11, wherein the further intercooler (4) is configured as a heat exchanger (82) configured as a tube (56) and/or tube bundle (56 a) and having a tube volume through which the fluid from the evaporator bottom sump (52) flows in order to enable indirect cooling of the steam.

13. Method for operating a heat pump (100), the heat pump having:

an evaporator (50) for evaporating a fluid in order to obtain an evaporated fluid, wherein the evaporator (50) has an evaporator bottom sump (52);

-a compressor having a first compressor stage (10) and a second compressor stage (20), wherein the compressor is arranged between the evaporator (50) and a condenser (60) along a flow direction of the evaporated fluid in operation of the heat pump (100) and is configured for compressing the evaporated fluid in order to obtain a compressed fluid; and

A condenser (60) for condensing the compressed fluid; and

-An intercooler (40) connected to the intercooler fluid supply line (3) and having an active element (42), wherein the active element (42) is arranged between the first compressor stage (10) and the second compressor stage (20),

Wherein the method comprises the following steps:

-delivering an intermediate cooling fluid from the evaporator bottom sump (52) into the active element (42) through the intermediate cooling fluid supply line (3);

Outputting a heated vaporous fluid through the first compressor stage (10);

The intermediate cooling fluid, which can be fed via the intermediate cooling fluid supply line (3), interacts with the heated vaporous fluid output by the first compressor stage (10) in order to cool the vaporous fluid.

14. Method for manufacturing a heat pump (100), the heat pump having:

an evaporator (50) for evaporating a fluid in order to obtain an evaporated fluid, wherein the evaporator (50) has an evaporator bottom sump (52);

-a compressor having a first compressor stage (10) and a second compressor stage (20), wherein the compressor is arranged between the evaporator (50) and a condenser (60) along a flow direction of the evaporated fluid in operation of the heat pump (100) and is configured for compressing the evaporated fluid in order to obtain a compressed fluid; and

A condenser (60) for condensing the compressed fluid;

Wherein the method comprises the following steps:

-arranging an intercooler (40) with an active element (42) between the first compressor stage (10) and the second compressor stage (20);

-connecting the intercooler (40) with an intercooler fluid supply line (3) extending from the evaporator sump (52) to the active element (42) so as to cause an interaction between the intercooler fluid, which can be delivered by the intercooler fluid supply line (3), and the heated vaporous fluid, which can be output by the first compressor stage (10), in operation of the heat pump (100).