DE102008011255A1 - Air conditioning system i.e. compression refrigerator, for automobile, has accumulator with super saturation device, and circulation medium present at nozzle outlet in single-phase aggregate condition when medium enters into passage - Google Patents

Abstract

The system (100) has an accumulator (6) with an accumulator inlet (6a) and an accumulator outlet (6b). An ejector pump main inlet (4a) is connected upstream to a heat exchanger passage (3.1). The accumulator outlet is connected downstream to a heat exchanger passage (3.2). The accumulator has a super saturation device (7) for cooling a circulation medium in the passage (3.1), such that the circulation medium is present in a nozzle outlet (4e) of a nozzle (4d) of an ejector pump (4) in a single-phase aggregate condition when the circulation medium enters into the passage (3.2). An independent claim is also included for a method for operating an air conditioning system for a motor vehicle.

Description

BACKGROUND OF THE INVENTION

Field of the invention

The The present invention relates to an air conditioning circuit having a internal heat exchanger, an accumulator and an ejector, as he, for example is used in a motor vehicle. The refrigeration cycle of the air conditioner is in terms of efficiency and mode of operation improved, since it designed according to the invention is and is driven or operated, that at the outlet of the nozzle of the ejector the circulating refrigerant always in single-phase state, d. H. that the propulsion jet the circulation medium in the ejector is always liquid.

at Air conditioning circuits, in which the circulating circulation medium undergoes state changes, which at the ideal running, rechtsläufigen Carnot process (cold vapor compression method) are ajar, is coming from a condenser or gas cooler, under high Compressed circulating medium expands in a throttle (Isentrope Relaxation at the left-hander Carnot cycle). The throttling process takes place under increasing the exergy of the circulation medium. The increase in exergy in the Circulation medium is not used efficiently here.

In the case, after which the effluent from the condenser circuit medium at a corresponding air conditioning is expanded in an ejector, may increase the exergy in the circulating medium during the throttling process used, the enthalpy of the circulation medium at the end of the Reduce throttling process.

consequently when entering an evaporator downstream of the ejector is, a circulating medium whose enthalpy is reduced or is reduced. At constant exit conditions at the exit of the Evaporator is therefore the enthalpy difference of the circulating medium larger when passing through the evaporator. This has the consequence that the heat absorption is increased from a refrigerated goods.

State of the art

however is at conventional Such air conditioning systems of the prior art in the ejector entering circulating medium with respect to the operation of the ejector unfavorable due to the present states of aggregation of the circulation medium, because the throttling process is a throttling or expansion of the Circulation medium in the mixed or wet steam area instead. With others Words is thus at the entrance to the ejector, the circulation medium partly in liquid and partly in gaseous form Condition before. The throttling of the circulation medium in the two-phase range As a consequence, there is no solid or stable jet of the circulating medium in the nozzle the ejector pump comes about. Consequently, the suction effect is on Side entrance of the ejector pump and thus the efficiency of the ejector pump due to an evaporation process of the circulating medium flowing in the ejector significantly reduced, as with a purely liquid jet of the circulation medium the case would be.

Various air conditioning systems with ejector pumps are known from the prior art. For example, US Patent Application No. US 2007 002 8630 (Denso Corp.) describes an ejector air conditioning circuit in which efficiency losses of the ejector due to a two-phase pumping of the circulating fluid are avoided by having a pre-throttle downstream of the condenser is, the pressure of the circulating medium is reduced and then the circulating medium flows in a Trockengrad-adjusting mechanism. The dryness adjustment mechanism has two outputs. One output is connected downstream to the main input of an ejector and the other output is connected via a throttle to the side input of the ejector. Further, downstream of the ejector and upstream of the throttle to the side of the ejector, an evaporator is provided to exchange heat with the climatic air, ie the external fluid. The dryness adjustment mechanism serves to separate or distribute the circulating medium in terms of its states of gaseous and liquid. In this air conditioning circuit, the ejector, ie the main inlet with the nozzle, mainly supplied with circulating medium in the gaseous state and at the throttle in the secondary circuit circulation medium is in the liquid state. Deficits in the operation of this air conditioner result from the fact that on the one hand by the throttling process in the pre-throttle, the increase in exergy in the circulation medium is not used. In other words, a large proportion of this pre-throttling energy is lost, resulting in a reduced efficiency of the ejector result. Further, at the main entrance of the ejector pump, there is circulation medium in a gaseous state, provided that the separation of the phases in the dryness adjustment mechanism works correspondingly well. This is achieved in that the dry-degree adjustment mechanism must be made correspondingly large. During operation of the ejector, that is, during the throttling process, however, liquid droplets are formed, which disturb the jet of the circulation medium in the ejector adversely.

Around the known from the prior art deficiencies in air conditioning systems with ejector pump to avoid and the efficiency of an air conditioner with an ejector pump, the following is described Invention proposed. An air conditioning circuit with ejector pump is disclosed. in which by the inventive design and arrangement ensures the components is that the jet of the circulation medium in the ejector in all operating states of the Air conditioning cycle a stable, single-phase beam with improved suction properties.

SUMMARY OF THE INVENTION

To proviso the invention is therefore an air conditioner, d. H. an air conditioning circuit with circulating medium circulating during operation of the air conditioning system intended. The inventive air conditioning comes in particular in a motor vehicle, such as a Automobile, used. The air conditioning system includes an ejector pump with an ejector main entrance, an ejector side entrance and an ejector output. Furthermore, the air conditioning system includes a respect the circulation medium inner heat exchanger with a first heat exchanger passage and a second heat exchanger passage. Furthermore, the air conditioner comprises an accumulator with a Akkumulatoreingang and a first, d. H. at least one, accumulator output. Of the Ejector main entrance is upstream, d. H. opposite to the flow direction of circulating circulating medium, with the first heat exchanger passage of the internal heat exchanger connected. The ejector output is downstream, i. H. in the direction of flowing circulating medium, with the accumulator input. connected. The first accumulator output is downstream with the second heat exchanger passage of internal heat exchanger connected. The accumulator comprises downstream of the circulating medium Accumulator a supersaturation device, it the circulating medium on entering the second heat exchanger passage allows the circulation medium in the first heat exchanger passage of the internal heat exchanger to cool like that that the circulation medium at least at the nozzle outlet of a nozzle of the ejector is present essentially in the single-phase state of aggregation.

Of the Refrigeration circuit the air conditioning system of the invention is therefore controlled, inter alia, by means of the supersaturation device, that the circulation medium downstream of the inner heat exchanger after exiting the first heat exchanger passage in a single-phase, d. H. purely liquid state of aggregation lower Temperature is present. Since the propulsion jet of the passing through the ejector Circulating medium liquid is, is an improved operation of the ejector and thus reached the entire air conditioning cycle. Opposite one conventional regarding the Circulatory medium two-phase working ejector can through the supersaturating device of internal heat exchanger in the second heat exchanger passage, d. H. on the low pressure side with a supersaturated circulation medium of higher liquid level be supplied or operated, so that the circulation medium in the first Heat exchange passage d. H. can be further cooled on the high pressure side of the inner heat exchanger. This has the consequence that the inlet temperature of the subsequently in the ejector pump entering circulating medium further reduced is and the circulation medium at the outlet of the propulsion jet in a purely liquid Aggregate state is present. The throttling process thus finds only in a single-phase state of aggregation. The one in the ejector Resulting motive or suction jet of the circulating medium thus remains while of flowing through the ejector liquid and stable. An expansion of circulation medium in the propellant jet of Ejector pump due to evaporation effects is avoided. moreover can due to the single-phase, purely liquid jet of the circulation medium the nozzle the ejector be designed so that the circulation medium with a high speed, for example greater than the speed of sound, flows, what another additional Pressure increase in the ejector, d. H. in the diffuser area of the ejector pump, leads.

According to one Another aspect of the present invention may be the supersaturation device inside the accumulator (liquid container, collector) be arranged. As a result, for example, a smaller footprint the air conditioning system of the invention reached.

Regarding one In another aspect of the present invention, the supersaturating means a main line, the inside of the accumulator at least partially U-shaped and / or is formed straight. The main line can be used to remove Circulatory medium in gaseous and / or liquid Aggregate state serve to an inventive operation of the air conditioner to ensure. Furthermore, such an improved and compact design of the accumulator or the supersaturation device reached.

According to a further aspect of the present invention, the vertex or the base of the at least partially U-tubular can main line in close proximity to an inner bottom surface of the accumulator.

According to one Another idea of the invention, the at least partially U-shaped main line at the apex or the base an opening exhibit. The opening can with appropriate arrangement or orientation of the accumulator in circulation medium liquid Aggregate state are located. about the opening can oil and / or circulating medium in liquid Flow the aggregate state into the main line.

In another embodiment the air conditioning system of the invention can the relationship of cross-sectional area the main to the cross-sectional area of the opening in the range of 0.5% up to 10%. By an enlarged cross-sectional area of the opening becomes For example, achieved that an increased demand of the internal heat exchanger, d. H. the second heat exchanger passage after circulation medium liquid Aggregate state can be covered. The increase in liquid circulation medium, which over sucked in the enlarged opening Among other things, the temperature of the environment can also be outside the air conditioning, with which the air conditioning exchanges heat. Due to high ambient temperatures, which require increased fluid for the internal heat exchanger on the low pressure side, takes the throughput, d. H. the mass flow or the speed the circulation medium such that the static pressure in the Main line due to the Bernoulli effect decreases and sucked more liquid circulation medium through the opening can be.

Corresponding In another aspect of the present invention, the supersaturating means in addition to the main line include a bypass line inside the accumulator and / or at least partially rectilinear and / or L-shaped is trained. The oil recirculation in The air conditioning circuit usually takes place via the opening in the main line. By means of the bypass line can an additionally required amount of liquid Circulation medium for oversaturating the low-pressure region the internal heat exchanger to disposal be placed to the circulation medium in the high pressure area of the internal heat exchanger continue to cool or liquefy and so the single-phase operation of the ejector as described above to ensure.

In Another example of the present invention may be the bypass line be connected to the main line. The supersaturating device can do so accomplished be that the bypass line is liquid Circulation medium leads and the main saturated, gaseous Circulation medium leads. The merger of both lines, especially at the output of the Accumulator and / or the supersaturation device, leads to one in oversaturated State present circulation medium, which then the internal heat exchanger supplied will and for further cooling the circulation medium on the high pressure side of the inner heat exchanger can be used.

To In another aspect of the present invention, a bypass line exit may be provided the bypass line curved and / or be formed angled and / or the / a bypass line output the bypass line at least partially in the cross-sectional area of the Main tower. Thus, for example, cheap or low-loss flow conditions for the circulating circulation medium created.

According to one Another aspect of the air conditioning system according to the invention can in the field of the bypass line exit the cross-sectional area of the main line steadily be diminished, d. H. to rejuvenate to a minimum. This creates an extra Suction effect in the bypass line of the supersaturation device, which liquid Circulating medium, d. H. Circulating medium in a liquid state.

Corresponding In another aspect of the present invention may be a bypass line input the bypass line in close proximity to the inner bottom surface of the Accumulator are located. For an application, according to which the accumulator substantially corresponding is arranged vertically, so that the bypass line entrance of liquid Circulation medium is surrounded, it can always, d. H. even at relative low liquid circulating medium level in the accumulator, liquid circulation medium in the bypass line for the inner heat exchanger to be provided.

According to one Another aspect of the present invention may be the ratio of flow capacity of the bypass line to the flow capacity of the main line range between 0.05 to 0.3.

To another embodiment the air conditioning system of the invention At least a portion of the supersaturation device may be Prandt1 tube-like be educated. As a result, as elsewhere called, favorable flow conditions for the Created circulation medium.

According to a further aspect of the invention may be located between the ejector and the accumulator, a preheater. The preheat exchanger can be used who the, further heat from a refrigerated goods, such as the environment of the air conditioning record.

To In another aspect of the present invention, the Accumulator include a second accumulator output, with the Ejektorpumpenseingangingang is connected and / or by means of an external line to the first Accumulator output is connected.

According to one Another aspect of the present invention may vary between the second accumulator output and the ejector side input a Throttle device and / or a low pressure heat exchanger are located.

Corresponding another embodiment the air conditioning system of the invention may be the second heat exchanger passage downstream with a compressor device and / or a high-pressure heat exchanger be connected and the compressor device and / or the high-pressure heat exchanger can downstream with the first heat exchanger passage be connected.

To In another aspect of the present invention, the High pressure heat exchanger in heat exchanging Relationship with a first closed circuit connected to the high pressure heat exchanger is coupled, stand.

In another embodiment the air conditioning system of the invention can the low pressure heat exchanger and / or the preheat exchanger in heat exchanging Relationship with a second closed circuit, which the low pressure heat exchanger and / or the preheat exchanger is coupled, stand.

According to one Another aspect of the present invention may be at least a portion the nozzle be similar to at least a portion of a Laval nozzle. This can be achieved be that liquid Circulation medium in the ejector, for example, on the speed of sound is accelerated.

Corresponding In another aspect, the accumulator may take the form of a be similar to cylindrical container. this leads to For example, to a compact and easy-to-manufacture structure.

To In another aspect of the present invention, a main line input the main line be positioned so that the circulation medium through the main line input substantially in the single-phase state of aggregation passes.

Intended is also a method for operating an air conditioner, in particular for a motor vehicle, the air conditioner having the above-described features and wherein the circulation medium is passed through the supersaturation device and the supersaturation device it the circulating medium when entering the second heat exchanger passage allows the circulation medium in the first heat exchanger passage to cool like that that the circulation medium at least at the nozzle outlet of the nozzle of the ejector Essentially emerges in the single-phase state of aggregation. By the inventive method is thus an efficient operation of the air conditioning system according to the invention, as described above.

It is, of course, that the above-mentioned disclosed features to achieve further versions the air conditioning system of the invention can be combined with each other as desired.

Further Features and features of the invention will become apparent by reference on the attached Figures from the following detailed description of an example the invention. This is purely exemplary and in no way restricting or limiting to understand. The detailed description is only intended to to provide the skilled person a teaching for reworking the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

1 Fig. 12 is a schematic diagram of an example of the air conditioning circuit according to the present invention;

2 is an enthalpy pressure state diagram for the circulating medium during operation of an example of the air conditioner according to the invention at an ambient temperature of 40 ° C .;

3 is another enthalpy pressure state diagram for the circulating medium during operation of an example of the air conditioner according to the invention at an ambient temperature of 30 ° C;

4 is another enthalpy pressure state diagram for the circulating medium during operation of an example of the air conditioner according to the invention at an ambient temperature of 20 ° C .;

5 FIG. 10 is an enthalpy pressure state diagram for the circulation medium during operation of an ejector-type air conditioner according to the related art; FIG.

6 is an overview of the liquid keitsanteil when entering the circulation medium in the low pressure region of the inner heat exchanger;

7 Fig. 12 is a cross-sectional view of an example of the connection of the main line of the supersaturation device to the bypass line of the supersaturation device;

8th is a cross-sectional view of an example of a battery of the air conditioner according to the invention.

DETAILED DESCRIPTION

In the following, the mode of operation and the structure of an example of the air conditioning system according to the invention will now be described 100 described.

The in 1 schematically illustrated, air conditioning circuit according to the invention 100 is designed as a compression refrigeration machine, which has an ejector cycle 100 includes. The operation of the ejector cycle 100 is based on the left-handed Carnot process.

A compressor 1 (Compressor) sucks at the compressor input 1a evaporated (vaporous), ie in gaseous state and under low pressure (about 40 bar to 50 bar) and low temperature (about 5 ° C to 8 ° C) standing circulating medium and compresses it. The circulation medium then leaves the compressor 1 at the compressor outlet 1b in a vapor state A (see Enthalpy-pressure-state diagrams of 2 to 4 ) of high temperature (about 130 ° C to 140 ° C) and high pressure (about 110 bar to 130 bar, preferably about 120 bar).

The compressor 1 For example, it can be designed as an externally controlled, oil-lubricated swash plate compressor with variable delivery capacity. According to an alternative aspect of the invention, the compressor is compressor 1 a variable power compressor which is electrically driven. This allows the flow of the circulating medium of the closed ejector cycle 100 as required, ie ambient conditions, adjust without affecting the speed of the drive unit of the motor vehicle. Constant air conditioning conditions can thus be realized easily. The compressor 1 can also be designed in terms of performance and controlled so that when idling the drive unit of the motor vehicle, a sufficient cooling capacity of the ejector cycle 100 is guaranteed.

As circulation medium (refrigerant) for the operation of the closed ejector cycle 100 For example, the chlorine-free and therefore environmentally compatible tetrafluoroethane (R134a) or the non-toxic carbon dioxide (R744) used in supercritical air conditioning systems can be used. In addition, the use of other other refrigerants is possible or conceivable.

That of the compressor 1 sucked and compressed circulation medium is in a condenser 2 (Condenser) acting heat exchanger liquefied by heat exchange. The capacitor 2 is located downstream of the compressor 1 , The property "downstream" means in the direction of the flowing circulating medium, ie in the direction of flow. <br/><br/> The property "upstream", which is still used below, correspondingly means in the opposite direction to the direction of the flowing circulating medium.

That in the condenser 2 at the capacitor input 2a entering, heated circulation medium in the gaseous state A is, for example, cooled by air (to about 50 ° C to 20 ° C). The air flows through cooling fins of the condenser 2 , whereby a heat release from the heated circulation medium takes place to the environment. The high pressure gaseous cycle medium begins during the cooling process in the condenser 2 gradually liquefy. At the capacitor output 2 B of the capacitor 2 the circulation medium is essentially in the liquid state B (see 2 to 4 ), but still contains a small proportion in the gaseous state.

Alternatively, the capacitor 2 also in heat exchanging relationship with another, self-contained cycle 51 which are connected to the capacitor 2 is coupled accordingly.

Alternative to the capacitor 2 during operation of the ejector cycle 100 with a circulating medium (eg, R134a) only in a subcritical state could be downstream of the compressor 1 to the compressor 1 immediately afterwards as a gas cooler 2 functioning heat exchanger are located. In this case, the operation of the ejector cycle 100 with a circulating medium which is present on the high-pressure side substantially in a supercritical state (eg carbon dioxide) and must be cooled accordingly be guaranteed. The further description is limited to a subcritically operated refrigeration cycle.

That from the condenser 2 at the capacitor output 2 B exiting, high pressure liquid / gaseous cycle medium (state B) then flows downstream into one ren heat exchanger 3 , The inner heat exchanger 3 includes a first heat exchanger passage 3.1 and a second heat exchanger passage 3.2 , The first heat exchanger passage 3.1 lies with regard to the circulation medium on the high pressure side (high pressure area) and the second heat exchanger passage 3.2 lies on the low pressure side (low pressure area).

The inner heat exchanger 3 serves to the liquid circulation medium on the high pressure side in the first heat exchanger passage 3.1 continue to liquefy or continue to cool (state C). This, withdrawn on the high pressure side of the circulating medium heat is in the inner heat exchanger 3 to the circulation medium in the intake of the compressor 1 transferred and used to transfer any existing or required circulation medium liquid state in the gaseous state L. This will prevent the compressor 1 sucking in liquid circulating medium and causing damage. The cooling of the circuit medium located on the high pressure side in the inner heat exchanger 3 takes place up to a certain temperature or enthalpy level, so that the circulation medium on the high pressure side in the liquid state C (see Enthalpy-pressure-state diagrams of 2 to 4 ) the inner heat exchanger 3 leaves.

The high pressure circulating medium now becomes in the inner heat exchanger 3 cooled down so that when it is on the high pressure side of the downstream ejector 4 is supplied, in a purely single-phase and saturated liquid state of aggregation (state D) at least at the nozzle exit 4e the nozzle 4d the ejector pump 4 escapes. The ejector pump 4 serves as a throttling device for the Kreislaufmedi order and thus to reduce the high-pressure circulating medium to a lower pressure.

The ejector pump 4 includes next to the nozzle 4d an ejector main entrance 4a , an ejector side entrance 4b and an ejector output 4c , In the ejector main entrance 4a the ejector pump 4 is located downstream, ie in the flow direction of the nozzle 4d , Following the nozzle 4d is located further downstream in the ejector 4 a diffuser structure 4f , The nozzle 4d For example, it may have the shape of a Laval nozzle or be at least partially similar to it.

That through the ejector main entrance 4a or through the nozzle 4d flowing liquid circulating medium expands in a single-phase state in the diffuser structure 4f , The one out of the nozzle 4d ie at the nozzle exit 4e Exiting liquid jet to circulation medium leads to an optimal suction effect for the circulation medium, which via the Ejektorpumpenseingangingang 4b into the ejector pump 4 flows.

The ejector pump 4 has on the circulating medium located in the high pressure area such an effect that during the passage of the circulating medium through the ejector 4 the liquid circulation medium by admixture of suction gas from the ejector side entrance 4b in a mist (gas phase and liquid phase) at a corresponding pressure (about 1.0 bar to 2.0 bar) and low temperature (about -5 ° C to -10 ° C) transformed.

The ejector pump 4 Downstream downstream is a respect to the circulation medium as a pre-heat exchanger or pre-evaporator 5 functioning heat exchanger. The pre-evaporator 5 now serves that at the pre-evaporator input 5a entering, two-phase present circulation medium (state E) evaporates, in which it absorbs heat from the refrigerated goods, for example, from the passenger compartment.

At the pre-evaporator outlet 5b the circulation medium exits in a two-phase state (state F), but with a higher gaseous content than when entering the pre-evaporator inlet 5a (Conditions). The pre-evaporator outlet 5b is downstream with the accumulator input 6a of the accumulator 6 (Liquid container, collector) connected. In another embodiment of the air conditioner according to the invention 100 can the pre-evaporator 5 also be omitted. Then the ejector output is 4c directly, without the interposition of a thermodynamic component influencing the state of aggregation of the circulating medium, with the accumulator inlet 6a connected.

The accumulator 6 is located on the suction side of the compressor 1 , Once the two-phase circulating medium in the accumulator 6 via the accumulator input 6a occurred, there is a separation of the circulation medium with respect to its two states of aggregation. In other words, there is in the accumulator 6 a reservoir with circulating medium in saturated gaseous state (saturated gas) (state H) and a reservoir with circulating medium in a saturated liquid state (saturated liquid) (state G).

In the event that the accumulator 6 is a conventional accumulator of the prior art and no supersaturation device 7 includes, lies at the first accumulator output 6b the circulation medium in saturated gaseous stood (state H).

In the in 1 schematically illustrated example of the air conditioner according to the invention 100 , ie the ejector cycle 100 includes the accumulator 6 another, second accumulator output 6c , The second accumulator output 6c is among other things to form a secondary circuit with the Ejektorpumpenseingangingang 4b , with a throttle device 8th and a throttle between 8th and the ejector side entrance 4b located low pressure heat exchanger 9 connected. The throttle device 8th is there to that at the ejector output 4c or in the accumulator 6 and thus also at the second accumulator output 6c present increased pressure level of the circulation medium according to the heat exchange process in the low-pressure heat exchanger 9 herabzusenken. The low pressure heat exchanger 9 serves to deprive a refrigerated goods, such as the air in a vehicle interior, the heat that is absorbed by the circulating medium.

In 1 includes the accumulator 6 but a supersaturation device 7 , The schematically represented supersaturation device 7 consists of a main line 7.1 (For example, a pipe made of plastic or metal), which is inside the accumulator 6 at least partially U-shaped tubular. Alternatively, the main line could 7.1 be formed substantially rectilinear and its input to the circulation medium be positioned so that circulation medium in always saturated gaseous state through the main line 7.1 flows. Furthermore, the supersaturation device comprises 7 a bypass line 7.2 which are also inside the accumulator 6 is trained. The bypass line 7.2 may be at least partially formed I-shaped, ie rectilinear and / or L-shaped. Based on 7 and 8th becomes an example of the supersaturating means 7 or the accumulator 6 with supersaturation device 7 explained in more detail.

The supersaturation device 7 As an alternative to the embodiment described above, it can also be realized that a conventional accumulator 6 of the prior art with a Akkumulatoreingang 6a , a first accumulator output 6b and a second accumulator output 6c is equipped, wherein the first accumulator output 6b and the second accumulator output 6c by means of an external line 7.3 outside the accumulator 6 are connected. The main line 7.1 then needs to be carried out only substantially rectilinear, with the entrance or entry of the main line 7.1 for the circulation medium in the reservoir with gaseous circulation medium. The main line 7.1 is always with the first accumulator output 6b connected. With such an arrangement, the liquid circulating medium is allowed through the external pipe 7.3 that from the first accumulator output 6b exiting gaseous cycle medium entering the second heat exchanger passage 3.2 of the internal heat exchanger 3 to oversaturate. The cross-section of the external line through which the circulating medium flows 7.3 is dimensioned correspondingly large in such an embodiment. The first accumulator output 6b and, if executed appropriately, the external line as well 7.3 is / are downstream with the second heat exchanger passage 3.2 of the internal heat exchanger 3 connected accordingly. About the external line 7.3 can also be oil, which is located in the bottom area of the accumulator 6 located, from the accumulator 6 stream. In the case of what essentially in the accumulator 6 accumulated oil from the accumulator 6 is to flow, the cross-section is the cross-section of the external line 7.3 correspondingly small dimensions. The external line 7.3 however, it does not need to be mandatory if the bypass line 7.2 trained accordingly and in the accumulator 6 is arranged. 8th shows a corresponding embodiment of the accumulator 6 or the supersaturation device 7 ,

The integration of the supersaturation device 7 now causes the saturated gaseous circulating medium from the accumulator 6 , which from the compressor 1 is sucked in, a certain amount of circulation medium in the liquid state is added by means of the bypass line 7.2 and / or the external line 7.3 , The inner heat exchanger 3 is thus on its low pressure side, ie in the second heat exchanger passage 3.2 supplied with supersaturated circulating medium. The supersaturated circulating medium is now capable of that on the high pressure side, ie in the first heat exchanger passage 3.1 the circulating medium located or circulating the inner heat exchanger so cool that the circulation medium in the high pressure region during the throttling process at least at the nozzle exit 4e in the ejector pump 4 is present as a saturated liquid. The inner heat exchanger 3 is dimensioned to increase its cooling capacity in this case, because the circulation medium enters with a high liquid content in the inner heat exchanger.

Due to the low temperature of the circulation medium at the ejector inlet 4a It is possible, during the entire throttling process a single-phase state of aggregation of the motive jet of the circulating medium in the ejector 4 to have and to receive. The efficiency of the ejector pump 4 is thus significantly improved.

The heat exchange of the pre-evaporator 5 and / or the low pressure heat exchanger 9 (Never derdruckverdampfer), as already described, can be done with the ambient air in a vehicle interior. Alternatively and / or additionally, however, the pre-evaporator 5 and / or the low pressure heat exchanger 9 in heat exchanging relationship with another external closed circuit 52 occur.

The proportion of liquid circulation medium is thus downstream of the accumulator 6 increased (state K). Another parameter, which influences the respectively required amount of circulation medium in the liquid state of aggregation, is the already described in detail operation of the air conditioning system according to the invention 100 to achieve is the ambient temperature, ie the load of the pre-evaporator 5 and / or the low pressure heat exchanger 9 (Evaporator). In a selected configuration of the air conditioning system according to the invention 100 For example, it has been found that the percentage of liquid circulating medium for the internal heat exchanger for achieving the above-described operation and characteristics is calculated as follows depending on the ambient temperature: Content of liquid circulation medium [mass%] = 0.0021 (ambient temperature ^ 2.59) +/- 10 %. 6 shows the course of the required mass fraction of liquid circulation medium in percent and the mass flow of the circulation medium as a function of the ambient temperature in kilograms per hour. It turns out 6 in that the required mass flow in the region of the ambient temperature of 20 ° C to 40 ° C increases approximately linearly from 60 kg / h to 180 kg / h.

The difference between the temperature of the circulation medium at the downstream exit of the first heat exchanger passage 3.1 of the internal heat exchanger 3 and the evaporation temperature at the downstream exit of the second heat exchanger passage 3.2 of the internal heat exchanger 3 is in a range of 2 K to 30 K, in particular in a range of 5 K to 10 K. The efficiency of the internal heat exchanger 3 is in the range of 50% to 90% (ratio of reached temperature difference in the high pressure area, ie first heat exchanger passage 3.1 to evaporator temperature in the low pressure range, ie in the second heat exchanger passage 3.2 ).

The 2 to 4 show, they have already been referred to above in corresponding places, enthalpy pressure-state diagrams for the circulation medium during the operation of an example of the air conditioner according to the invention 100 at ambient temperatures of 40 ° C ( 2 ), 30 ° C ( 3 ) and 20 ° C ( 4 ). The ejector cycle 100 (See. 1 ) is operated so that on the high pressure side of the refrigeration cycle, ie between the compressor output 1b and the ejector main entrance 4a a pressure of 120 bar is present. Furthermore, in the low-pressure region (second heat exchanger passage 3.2 ) an evaporator temperature of always 7 ° C before.

In the case where the ambient temperature is 40 ° C ( 2 ) and thus a high load on the low-pressure heat exchanger 9 and / or the pre-evaporator 5 is present, the amount of liquid circulation medium at the entrance or entrance of the second heat exchanger passage 3.2 of the internal heat exchanger 3 , which downstream of the first accumulator output 6b (State H) is greatly increased (state K), so that the high-pressure side located in the first heat exchanger passage 3.1 of the internal heat exchanger 3 by evaporation of the circulation medium in the low-pressure region (second heat exchanger passage 3.2 ) can be cooled (states B to C). Due to the high liquid content on the low pressure side of the inner heat exchanger 3 (Condition K) has the increase in enthalpy of the circulation medium (K state to L) in the inner heat exchanger 3 no effect on the compression end temperature, ie the temperature of the circulation medium after the compressor 1 (Condition A). Thus, also the power requirement of the compressor 1 improved, ie reduced.

3 shows the state changes of the circulation medium at an ambient temperature of 30 ° C. Compared to an ambient temperature of 40 ° C can here due to the reduced ambient temperature, the liquid content of circulation medium for the low pressure range 3.2 of the internal heat exchanger 3 be reduced accordingly (state K). A propulsion jet of the circulation medium in liquid state of aggregation at least at the nozzle outlet 4e in the ejector (state D) is still achieved because that from the condenser or gas cooler 2 emerging circulating medium already has a lower temperature. The same applies to the case where the ambient temperature is 20 ° C (cf. 4 ).

5 shows the state changes of the circulation medium in the operation of a ejector air conditioning system of the prior art. This clearly shows that the ejector pump is operated with a circulating medium which is operated in a two-phase state of aggregation (state D). The circulation medium in a saturated gaseous state at the accumulator output (state H) and receives only a very small proportion of liquid from the bottom region of the accumulator (state G). This proportion of liquid has its cause in that only to be avoided, that accumulates oil in the accumulator. On the low pressure side of the internal heat exchanger increases the enthalpy of the circulating medium (states K to L). With this increase in enthalpy is a cooling of the circulation medium on the high pressure side of the inner heat exchanger connected (states B to C). However, the enthalpy of the circulation medium at the inlet of the ejector (state C) is still so high that during the throttling process, the circulation medium is transferred to the two-phase region and does not come to rest on the liquid saturation line to the left of the critical point with respect to its state of aggregation. Such an ejector cycle thus has deficits in terms of operation and efficiency compared to the ejector cycle according to the invention.

7 shows a section of an example of the supersaturation device 7 , The supersaturation device 7 is located in particular inside the accumulator 6 (not in 7 shown - Cf. 1 and 8th ). The supersaturation device 7 consists of a configuration of conduits for the circulation medium, which Prandt1 tube-like design and will be described in more detail below.

The supersaturation device 7 consists of the main line 7.1 and the bypass line 7.2 , About the main line 7.1 On the one hand circulating medium is sucked in saturated gaseous state of aggregation as well as in liquid state of aggregation. In the bypass line 7.2 Circulating medium flows in saturated liquid state of aggregation from the corresponding reservoir in the accumulator 6 (See. 1 and 8th ). The operation or effects of the supersaturation device for the operation of the ejector cycle 100 have already been presented above and will not be explained at this point.

The main line 7.1 is with the bypass line 7.2 connected. The bypass line 7.2 owns like the main line 7.1 advantageous for example a circular flow cross-section. The bypass line 7.2 protrudes with its bypass line output 7.2b in the flow cross-section of the main line 7.1 , The bypass line 7.2 is in the area of the main line 7.1 L-shaped, ie angled, formed and in such a way that the bypass line output 7.2b or its cross section downstream of the main line 7.1 to the first accumulator output 6b located.

In the area of the angled bypass line 7.2 is the flow area of the main pipe 7.1 also constantly reduced to a minimum. This leads to an improved suction effect with respect to the circulation medium in liquid state.

8th schematically shows an accumulator 6 , which is a supersaturating device 7 includes. The accumulator 6 is designed such that its housing is substantially similar to a cylindrical container. The accumulator 6 has an accumulator input 6a , a first accumulator output 6b and a second accumulator output 6c , The second accumulator output 6c is to form the secondary circuit (Cf. 1 ) with the throttle device 8th , the low pressure heat exchanger 9 (not in 8th shown) as well as with the ejector side entrance 4b connected.

The accumulator input 6a is tube-like and protrudes to a certain length L6a in the interior of the accumulator 6 , About the accumulator input 6a flows circulating medium, which optionally from a pre-evaporator 5 , but in any case by an ejector output 4c comes, in the interior of the accumulator 6 ,

The in 8th shown accumulator 6 further comprises a supersaturation device 7 in the form of a main line 7.1 and a bypass line 7.2 , The main line 7.1 is with the bypass line 7.2 inside the accumulator 6 just before the first accumulator output 6b connected.

The main line 7.1 is U-shaped tube. To the U-tubular shape of the main pipe 7.1 Adds a section which leads to the first accumulator output 6b is substantially rectilinear. The bypass line 7.2 is im in the 8th shown example formed substantially straight and in the rectilinear region of the main line 7.1 with the main 7.1 connected. The bypass line output 7.2b or the cross section is transverse to the flow of the circulating medium in the main line 7.1 , As already shown 7 shown, the bypass line output 7.2b also angled, for example, be executed at right angles. The bypass line 7.2 is in close proximity to the side wall of the accumulator 6 arranged extends along the height H6 of the accumulator until just before the inner bottom surface 6d of the accumulator 6 so that the bypass line input 7.2a in close proximity to the inner floor surface 6d of the accumulator 6 located. Possibly there enriched oil can thus be sucked through the bypass line.

The base or the vertex 7.1a the U-tubular main 7.1 the supersaturation device 7 is located in the 8th shown accumulator 6 with supersaturation device 7 in close proximity to the inner floor surface 6d of the accumulator 6 , The vertex 7.1a has an opening at its outer end 7.1b on. About the opening 7.1b can oil and / or liquid circulation medium in the main line 7.1 stream. The opening 7.1b is ever but usually dimensioned so in terms of their cross-section that only a very small proportion of liquid circulation medium flows through.

The main entrance 7.1c is located at the end of one leg of the U-shaped tube 7.1 in the range of the gaseous circulating medium. The ratio of the cross-sectional area of the main line input 7.1c to the cross-sectional area of the opening 7.1b is for example in the range of 0.5% to 10%. Furthermore, the ratio of flow capacity of the bypass line is 7.2 at the bypass line entrance 7.2a to the flow capacity of the main line 7.1 for example in the range between 0.05 to 0.3.

Furthermore, the second accumulator output could 6c with the external line 7.3 be connected (not in 8th shown), the external line 7.3 instead of the bypass line 7.2 or additionally the second heat exchanger passage 3.2 (Low pressure area) of the inner heat exchanger 3 (See. 1 ) supplied with circulating medium in a liquid state.

Also conceivable is an enlargement of the opening 7.1b to the liquid content in the main line 7.1 to increase.

With The invention described above is a with respect to the operation and Economy optimally working air conditioning provided.

Claims (23)

Air conditioning ( 100 ), in particular for a motor vehicle, comprising: an ejector pump ( 4 ) with an ejector main entrance ( 4a ), an ejector side entrance ( 4b ) and an ejector output ( 4c ); a relative to the circulation medium inner heat exchanger ( 3 ) with a first heat exchanger passage ( 3.1 ) and a second heat exchanger passage ( 3.2 ); an accumulator ( 6 ) with an accumulator input ( 6a ) and a first accumulator output ( 6b ); wherein the ejector main entrance ( 4a ) upstream with the first heat exchanger passage ( 3.1 ) connected is; where the ejector output ( 4c ) downstream with the accumulator input ( 6a ) connected is; the first accumulator output ( 6b ) downstream with the second heat exchanger passage ( 3.2 ) connected is; the accumulator ( 6 ) a supersaturating device ( 7 ), which allows the circulating medium to enter the second heat exchanger passage (FIG. 3.2 ) allows the circulating medium in the first heat exchanger passage ( 3.1 ) such that the circulation medium at least at the nozzle exit ( 4e ) of a nozzle ( 4d ) of the ejector pump ( 4 ) is present essentially in the single-phase state of aggregation. Air conditioning ( 100 ) according to claim 1, wherein the supersaturating device ( 7 ) inside the accumulator ( 6 ) is arranged. Air conditioning ( 100 ) according to one of the preceding claims, wherein the supersaturating device ( 7 ) a main line ( 7.1 ) inside the accumulator ( 6 ) is at least partially U-shaped tubular and / or rectilinear. Air conditioning ( 100 ) according to claim 3, wherein the vertex ( 7.1a ) of the main line ( 7.1 ) in close proximity to an inner floor surface ( 6d ) of the accumulator ( 6 ) is located. Air conditioning ( 100 ) according to claim 3 or 4, wherein the main line ( 7.1 ) at the vertex ( 7.1a ) an opening ( 7.1b ) having. Air conditioning ( 100 ) according to claim 5, wherein the ratio of the cross-sectional area of the main line ( 7.1 ) to the cross-sectional area of the opening ( 7.1b ) ranges from 0.5% to 10%. Air conditioning ( 100 ) according to one of the preceding claims, wherein the supersaturating device ( 7 ) a bypass line ( 7.2 ) inside the accumulator ( 6 ) and / or at least partially rectilinear and / or L-shaped. Air conditioning ( 100 ) according to claim 7, wherein the bypass line ( 7.2 ) with the main line ( 7.1 ) connected is. Air conditioning ( 100 ) according to claim 7 or 8, wherein a bypass line exit ( 7.2b ) of the bypass line ( 7.2 ) is curved and / or angled and / or wherein the / a bypass line exit ( 7.2b ) of the bypass line ( 7.2 ) at least partially in the cross-sectional area of the main line ( 7.1 protrudes. Air conditioning ( 100 ) according to claim 9, wherein in the region of the bypass line exit ( 7.2b ) the cross-sectional area of the main line ( 7.1 ) is steadily reduced. Air conditioning ( 100 ) according to one of claims 7 to 10, wherein a bypass line input ( 7.2a ) of the bypass line ( 7.2 ) in close proximity to the inner floor surface ( 6d ) of the accumulator ( 6 ) is located. Air conditioning ( 100 ) according to one of the preceding claims 7 to 11, wherein the ratio of flow capacity of the bypass line ( 7.2 ) to the flow capacity of the main line ( 7.1 ) ranges between 0.05 to 0.3. Air conditioning ( 100 ) according to one of the preceding claims, wherein at least a portion of the supersaturating device ( 7 ) Prandt1 tube-like is formed. Air conditioning ( 100 ) according to one of the preceding claims, wherein between the ejector ( 4 ) and the accumulator ( 6 ) a preheat exchanger ( 5 ) is located. Air conditioning ( 100 ) according to one of the preceding claims, wherein the accumulator ( 6 ) a second accumulator output ( 6c ) connected to the ejector side entrance ( 4b ) and / or by means of an external line ( 7.3 ) with the first accumulator output ( 6b ). Air conditioning ( 100 ) according to claim 15, wherein between the second accumulator output ( 6c ) and the ejector side entrance ( 4b ) a throttle device ( 8th ) and / or a low-pressure heat exchanger ( 9 ) is located. Air conditioning ( 100 ) according to one of the preceding claims, wherein the second heat exchanger passage ( 3.2 ) downstream with a compressor device ( 1 ) and / or a high-pressure heat exchanger ( 2 ) and wherein the compressor device ( 1 ) and / or the high-pressure heat exchanger ( 2 ) downstream with the first heat exchanger passage ( 3.1 ) connected is. Air conditioning ( 100 ) according to claim 17, wherein the high-pressure heat exchanger ( 2 ) in heat exchanging relationship with a first closed circuit ( 51 ), which is connected to the high-pressure heat exchanger ( 2 ) is coupled. Air conditioning ( 100 ) according to claim 16, wherein the low-pressure heat exchanger ( 9 ) and / or the preheat exchanger ( 5 ) in heat exchanging relationship with a second closed circuit ( 52 ), which is connected to the low-pressure heat exchanger ( 9 ) and / or the preheat exchanger ( 5 ) is coupled. Air conditioning ( 100 ) according to one of the preceding claims, wherein at least a portion of the nozzle ( 4d ) is similar to at least a portion of a Laval nozzle. Air conditioning ( 100 ) according to one of the preceding claims, wherein the accumulator ( 6 ) is similar to the shape of a cylindrical container. Air conditioning ( 100 ) according to claim 3 or 4, wherein a main line entrance ( 7.1c ) of the main line ( 7.1 ) is positioned so that the circulation medium passes substantially in the single-phase state of aggregation. Method for operating an air conditioning system ( 100 ), in particular for a motor vehicle, the air conditioning system ( 100 ) an ejector pump ( 4 ) with an ejector main entrance ( 4a ), an ejector side entrance ( 4b ) and an ejector output ( 4c ) and a with respect to the circulating medium internal heat exchanger ( 3 ) with a first heat exchanger passage ( 3.1 ) and a second heat exchanger passage ( 3.2 ) as well as an accumulator ( 6 ) with an accumulator input ( 6a ) and a first accumulator output ( 6b ); wherein the ejector main entrance ( 4a ) upstream with the first heat exchanger passage ( 3.1 ) connected is; where the ejector output ( 4c ) downstream with the accumulator input ( 6a ) connected is; the first accumulator output ( 6b ) downstream with the second heat exchanger passage ( 3.2 ) connected is; the accumulator ( 6 ) a supersaturating device ( 7 ), through which the circulating medium is guided, wherein the supersaturation device ( 7 ) it the circulating medium when entering the second heat exchanger passage ( 3.2 ) allows the circulating medium in the first heat exchanger passage ( 3.1 ) such that the circulation medium at least at the nozzle exit ( 4e ) of a nozzle ( 4d ) of the ejector pump ( 4 ) emerges essentially in the single-phase state of aggregation.