CN110486943A - The not exclusively cooling moderate and high temperature heat system of throttling among the more condensers of multi-stage compression - Google Patents

Abstract

The invention discloses a multi-stage compression multi-condenser intermediate throttling incomplete cooling multi-stage medium-high temperature heat pump system. The invention consists of evaporators, compressors of all levels, condensers of all levels, throttling valves of all levels, bypass throttling valves of all levels and regenerators of all levels. Heating is used to produce ordinary domestic hot water, medium-high temperature hot water and high-pressure steam for industrial use. Through the multi-stage compression and multi-stage condensation process of the refrigerant, the room temperature water is heated multiple times continuously, which can significantly reduce the irreversible loss of heat exchange with the refrigerant during the heating process of the room temperature water, and the compression ratio of the compressors at each stage is small, and The exhaust temperature of the compressor is reduced by throttling and reducing the pressure through the bypass throttle valve. The heating hot water heating pipeline connected in parallel between the condenser and the regenerator can be used for room heating to realize cascade utilization of heat.

Description

Medium and high temperature heat pump system with multi-stage compression and multi-condenser intermediate throttling incomplete cooling

technical field

The invention relates to the technical field of heat pumps, in particular to a medium-high temperature heat pump system for incomplete cooling with intermediate throttling in the middle of multi-stage compression and multiple condensers.

Background technique

There is a wide demand for medium-high temperature hot water and steam in life and industry. However, the production of medium-high temperature hot water often consumes a lot of power and fuel resources. Heat pump products have been widely used as a clean, efficient and stable heating equipment. Further improving the energy efficiency of heat pump equipment has important practical significance and social value for promoting energy conservation and emission reduction and improving economic benefits.

The condensing temperature of the conventional medium-high temperature heat pump system is constant, and the normal temperature water is directly heated in the condenser, and the temperature difference between the inlet and outlet of the normal temperature water is relatively large, which is limited by the heat transfer temperature difference between the refrigerant in the condenser and the normal temperature water, and the heat transfer of the fluids on both sides of the condenser The temperature difference distribution is seriously uneven, resulting in a large average heat transfer temperature difference in the condenser, large irreversible losses during the heat transfer process, and low energy efficiency of the system. Conventional single-stage compression heat pump systems using non-azeotropic working fluids have similar temperature glides in the evaporation and condensation processes, and are suitable for working conditions where the temperature changes of heat exchange fluids on the heat source and heat sink sides are close, but for medium and high temperature heat pump systems, the heat source The temperature change on the side of the heat sink is generally small, and the temperature rise of the water or steam on the heat sink side is relatively large or very large, which is much greater than the temperature drop of the fluid on the heat source side. And for the working conditions with large temperature span of heat source and heat sink, the compression ratio of the conventional compressor is large, and the efficiency of the compressor is low.

Contents of the invention

The invention provides a medium-high temperature heat pump system adopting multi-stage compression and multi-stage condensation to solve the problems of large irreversible loss in the heat exchange process, large compression ratio and low energy efficiency of the system.

The technical scheme adopted by the high-temperature heat pump system in the middle throttling incomplete cooling of the multi-stage compression multi-condenser of the present invention is: 3≤i≤n-1 in the system, n≥4;

The outlet of the first-stage compressor 3 is connected to the inlet of the working medium side of the first-stage condenser 4, the outlet of the working medium side of the first-stage compressor 3 is connected to the inlet of the superheated gas side of the second-stage regenerator 6, and the second-stage regenerator 6 The outlet of the superheated gas side is connected to the second-stage compressor 8, the outlet of the first-stage condenser 4 is connected to the inlet of the first-stage throttle valve 5, and the outlet of the second-stage throttle valve 11 is connected to the first-stage throttle valve 5 inlets are connected, the two-phase fluid side outlet of the second-stage regenerator 6 is connected with the inlet of the first-stage throttle valve 5, the outlet of the first-stage throttle valve 5 is connected with the working medium side inlet of the evaporator 1, and the working medium of the evaporator 1 The side outlet is connected to the inlet of the first-stage compressor 3; the working medium side outlet of the second-stage condenser 9 is connected to the second-stage regenerator 6 through the pipeline provided with the second-stage bypass throttle valve 7;

The outlet of the i-1th stage compressor is connected to the inlet of the superheated gas side of the i-stage regenerator 12, the outlet of the i-th stage regenerator 12 is connected to the inlet of the i-stage compressor 13, and the outlet of the i-stage compressor 13 It is connected to the inlet of the superheated gas side of the i+1 stage regenerator, the outlet of the i-stage compressor 13 is connected to the inlet of the i-stage condenser 15 on the working medium side, and the outlet of the i-stage condenser 15 on the working medium side is connected to the i-stage section The inlet of the flow valve 16 is connected, the outlet of the i+1th stage throttle valve is connected to the inlet of the i-th stage throttle valve 16, the outlet of the two-phase fluid side of the i+1th stage regenerator is connected to the inlet of the i-th stage throttle valve 16, The outlet of the i-th stage throttle valve 16 is connected to the i-1th stage throttle valve inlet; the i-stage condenser 15 working fluid side outlet is connected to the i-stage bypass throttle valve 14 inlet, The outlet of the valve 14 is connected to the two-phase fluid side inlet of the i-th stage regenerator 12, and the two-phase fluid side outlet of the i-th stage regenerator 12 is connected to the i-1th stage throttle valve inlet;

The outlet of the n-1th stage compressor is connected to the inlet of the superheated gas side of the nth stage regenerator 18, the outlet of the superheated gas side of the nth stage regenerator 18 is connected to the inlet of the nth stage compressor 19, and the outlet of the nth stage compressor 19 It is connected to the inlet of the working medium side of the nth stage condenser 17, the outlet of the working medium side of the nth stage condenser 17 is connected to the inlet of the nth stage throttle valve 10, and the outlet of the nth stage throttle valve 10 is connected to the n-1th stage throttling valve The inlet of the valve is connected; the working medium side outlet of the nth stage condenser 17 is connected with the nth stage bypass throttle valve 20 inlet, and the nth stage bypass throttle valve 20 outlet is connected with the nth stage regenerator 18 two-phase fluid side inlet The two-phase fluid side outlet of the nth stage regenerator 18 is connected with the n-1th stage throttle valve inlet;

The normal temperature water outlet is connected to the heat exchange fluid side inlet of the first stage condenser 4, the heat exchange fluid side outlet of the first stage condenser 4 is connected to the heat exchange fluid side inlet of the second stage condenser 9, and the second stage condenser 9 is heat exchanged The fluid side outlet is connected to the heat exchange fluid side inlet of the third-stage condenser, the heat exchange fluid side outlet of the i-th stage condenser 15 is connected to the heat-exchange fluid side inlet of the i+1-th stage condenser, and the n-1-th stage condenser The hot fluid side inlet is connected to the heat exchange fluid side inlet of the nth stage condenser 17, and the heat exchange fluid side outlet of the nth stage condenser 17 is connected to the medium-high temperature hot water or high temperature steam inlet.

The working fluid used is pure refrigerant, or CO ₂ /R1234ze(E), CO ₂ /R1234ze(Z), CO ₂ /R1234yf, R41/R1234ze(E), R41/R1234ze(Z), R41/R1234yf, R32/R1234ze(E), R32/R1234ze(Z), R32/R1234yf and other non-azeotropic working fluids. For non-azeotropic mixed working fluids, choose a refrigerant whose temperature glide is equivalent to the temperature difference between the inlet and outlet of the heat exchange fluid in the evaporator.

Multi-stage compression multi-condenser intermediate throttling incomplete cooling medium and high temperature heat pump system can be set to multi-stage (referred to as n-stage) according to process requirements. The higher the temperature rise, the more stages are set.

The principle of determining the number of series is: in order to ensure that the heat exchange process of the evaporator and the condenser matches at the same time, according to the process requirements, the temperature rise of the normal temperature water heating and the temperature drop of the heat source heat exchange fluid are calculated (temperature rise of the normal temperature water heating / heat source heat exchange fluid Cooling temperature drop), rounded up as the series of the system.

The system of the present invention can also connect each temperature-level condenser and each temperature-level regenerator in parallel to heat the hot water heating pipeline, and apply it as a multi-stage compression multi-condenser intermediate throttling incomplete cooling heat pump dual-supply system. The heat supply end can be equipped with fan coils, floor pipes, radiators and other devices, and the condensers and regenerators at all levels can directly provide heat for room heating to realize heat cascade utilization.

Compared with prior art, the advantages and positive effects that the present invention has are:

(1) Compared with the conventional pure single-stage compression heat pump system, in the present invention, the normal temperature water is continuously heated in the multi-stage condenser, the temperature rise of the water in the condensers of each stage is lower, and the condensation process of each temperature position of the refrigerant is the same as The normal temperature water heating process forms a good temperature match, which can significantly reduce the heat exchange temperature difference between the heat exchange fluid and the working fluid, and reduce the irreversible loss of heat exchange between the heat exchange fluid and the refrigerant. Improve efficiency and effectively improve the COP of the cycle;

(2) For a conventional single-stage compression heat pump system using a non-azeotropic working fluid, it is difficult for the working fluid in the evaporator and condenser to match the temperature of the heat exchange fluid at the same time. Compared with the conventional non-azeotropic working medium single-stage compression heat pump system, the heating process of the normal temperature water in the present invention goes through two or more continuous temperature rises, and the temperature rise in each heating process is not high, and evaporates with the non-azeotropic refrigerant The process and the condensation process at each temperature level form a good temperature match. Through the present invention, the simultaneous matching of the fluids on both sides of the evaporator and the condenser can be realized, the irreversible heat exchange loss is greatly reduced, and the system is further improved. Efficiency and energy efficiency, improve economic benefits;

(3) The air delivery capacity of the second-stage compressor is less, and the air intake capacity of the compressor is reduced. Compared with the single-stage heat pump system under the same normal temperature water temperature rise condition, the power consumption of the compressor of the present invention is significantly reduced;

(4) Compared with the traditional single-stage compression, the pressure ratio of the multi-stage compression process is reduced, and the isentropic efficiency of the compressor is improved. In addition, the device of the present invention is provided with an intermediate throttling process to cool the superheated gas at the outlet of the compressor, thereby reducing the exhaust temperature and prolonging the service life of the compressor;

(5) This device can be used for heating, domestic hot water production, medium-high temperature hot water and high-pressure steam for industrial use at the same time. It has a wide range of uses and has a good development prospect.

Description of drawings

Figure 1 is a diagram of a medium and high temperature heat pump system with two-stage compression and two condensers with intermediate throttling and incomplete cooling;

Fig. 2 is a temperature-enthalpy diagram of a medium-high temperature heat pump system with two-stage pure-compression double-condenser intermediate throttling incomplete cooling;

Fig. 3 is a temperature-enthalpy diagram of a medium-high temperature heat pump system with two-stage non-azeotropic working fluid compression and double-condenser intermediate throttling incomplete cooling;

Figure 4 is a diagram of a two-stage compression double condenser intermediate throttling incomplete cooling heat pump dual supply system diagram;

Fig. 5 is a diagram of a medium-high temperature heat pump system for incomplete cooling of a multi-stage compression multi-stage condenser with intermediate throttling.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings.

Example 1: Medium- and high-temperature heat pump system with two-stage compression and two-condenser intermediate throttling incomplete cooling

The system consists of the first-stage heat pump cycle, the second-stage heat pump cycle and the continuous heating process of normal temperature water. The system is shown in Figure 1.

(1) If the system uses pure working fluid, the temperature-enthalpy diagram of the high-temperature heat pump system in the two-stage pure-compression double-condenser intermediate throttling incomplete cooling is shown in Figure 2. The specific implementation is as follows:

Step 1: The first-stage compressor 3 sucks the low-temperature and low-pressure working fluid at the outlet of the working fluid side of the evaporator 2 (as shown in Figure 2, state 1), and compresses it into a medium-temperature and medium-pressure superheated gas (as shown in Figure 2, state 2) , then the superheated gas is divided into two paths. One path of gas flows into the inlet of the working medium side of the first-stage condenser 4, and the working medium in the condenser is condensed to a saturated liquid (as shown in state 10 in Figure 2), and the normal temperature water (as shown in Figure 2 state w1) is heated to a certain temperature (as shown in Figure 2 state w2). Afterwards, the working medium enters the first-stage throttling valve 5 to throttle and reduce pressure to a two-phase fluid state (as shown in state 12 in Figure 2), and the gas-liquid two-phase fluid enters the working medium side inlet of the evaporator 2, and the working medium evaporates and absorbs the heat of normal temperature water It becomes a saturated gas state (as shown in state 1 in Figure 2), and is sucked by the first-stage compressor 3.

Second step: another path of superheated gas flowing out from the first-stage compressor 3 flows into the regenerator 6 and is cooled to state 3 in FIG. Figure 2 state 4), then flow into the second stage condenser 9 working fluid side inlet, working fluid and the heat exchange fluid (hot water or steam) flowing out from the heat exchange fluid side of the first stage condenser (as shown in Figure 2 state w2 and w3, w2 and w3 are in the same state) for heat exchange, the temperature drops to state 6 in Fig. 2, and the heat exchange fluid is further heated to state w4 in Fig. 2 .

Step 3: The working medium flowing out of the second-stage condenser 9 is also divided into two paths, one of which flows through the second-stage bypass throttle valve 7 to throttle and reduce pressure, and becomes a gas-liquid two-phase fluid state (as shown in Figure 2. 7). The gas-liquid two-phase fluid after throttling and decompression exchanges heat with the high-temperature gas flowing out of the first-stage compressor 3 in the regenerator 6, and the discharge temperature of the first-stage compressor drops to state 3 in Figure 2, and the gas-liquid The two-phase fluid absorbs heat and evaporates into a saturated gas state as shown in state 8 in Figure 2. The other working medium flowing out of the second-stage condenser 9 flows through the second-stage throttling valve 10 to reduce the pressure and become a gas-liquid two-phase state (as shown in state 7 in FIG. 2 ). The saturated gas at the outlet of the working fluid side of the regenerator 6 is mixed with the gas-liquid two-phase fluid at the outlet of the throttle valve 10 to state 9 in FIG. 2 , and then mixed with the medium-pressure fluid (such as State 10 in Figure 2) The three fluids are mixed to State 11 in Figure 2, and then flow through the first-stage throttle valve 5 to further throttle to State 12 in Figure 2 and then enter the working medium side inlet of the evaporator 2, and the working medium absorbs heat and becomes a saturated gas state (as shown in state 1 in Figure 2), it is sucked by the first-stage compressor 1 to complete the heat pump cycle.

Step 4: Normal temperature water (as shown in state w1 in Figure 2) first flows into the heat exchange fluid side of the first-stage condenser 4 to be heated to state w2 (w3) in Figure 2, and then flows into the second-stage condenser 9 (as shown in state w3 in Figure 2 ) side inlet of the heat exchange fluid is heated to the temperature required by the process (as shown in Figure 2, state w4), to obtain the required medium-high temperature hot water or high-temperature steam, and complete the continuous heating process of normal temperature water.

(2) If a non-azeotropic mixed working fluid is used, the matching characteristics of the refrigerant in the high-temperature heat pump system of the two-stage compression double-condenser intermediate throttling incomplete cooling and the heating process of normal temperature water will be more excellent, which can further improve the energy efficiency of the system. Improve economic efficiency. The temperature-enthalpy diagram of the medium-high temperature heat pump system for the two-stage non-azeotropic working medium compression double-condenser intermediate throttling incomplete cooling is shown in Figure 3.

The specific implementation is as follows:

Step 1: The first-stage compressor 3 sucks the low-temperature and low-pressure working fluid at the outlet of the working medium side of the evaporator 2 (as shown in Figure 3, state 1), and compresses it into medium-pressure superheated gas (as shown in Figure 3, state 2), The gas then splits into two paths. All the way flows into the inlet of the working medium side of the first-stage condenser 4, and the working medium in the condenser condenses to a saturated liquid (as shown in state 11 in Figure 3), and heats the normal temperature water on the side of the heat exchange fluid (as shown in state w1 in Figure 3) to a certain temperature (As shown in Figure 3 state w2). Afterwards, the working medium enters the first-stage throttle valve 5 to throttling and depressurizes to a two-phase fluid state (as shown in state 12 in Figure 3), and the gas-liquid two-phase fluid enters the working medium side inlet of the evaporator 2, and the working medium absorbs the heat of normal temperature water and becomes It is in a saturated gas state (as shown in state 1 in Figure 3), and is inhaled by the first-stage compressor 3.

Step 2: Another gas flow out of the first-stage compressor 3 flows into the superheated gas side of the regenerator 6 to cool down to the state 3 in Figure 3, and then enters the second-stage compressor 8, and the working medium is compressed into a high-temperature and high-pressure fluid ( As shown in Figure 3 State 4), it flows into the inlet of the working medium side of the second stage condenser 9, and is the same as the heat exchange fluid flowing out from the heat exchange fluid side of the first stage condenser 4 (as shown in Figure 3 State w2 and w3, w2 and w3 are the same state) for heat exchange, the temperature drops to state 6 in Fig. 3, and the heat exchange fluid is further heated to state w4 in Fig. 3 .

Step 3: The working medium flowing out of the second-stage condenser 9 is also divided into two paths, one of which flows through the second-stage bypass throttle valve 7 to throttle and reduce pressure, and becomes a gas-liquid two-phase fluid state (as shown in Figure 3. 7). The gas-liquid two-phase fluid after throttling and depressurization exchanges heat with the high-temperature working fluid flowing out of the first-stage compressor 1 in the regenerator 6, and the discharge temperature of the first-stage compressor drops to state 3 in Figure 3, The gas-liquid two-phase fluid absorbs heat and evaporates into a saturated gas state (as shown in state 10 in Figure 3). Another path of working fluid flowing out of the second-stage condenser 9 flows through the second-stage throttle valve 10 to throttle and reduce pressure, and becomes a gas-liquid two-phase state (as shown in state 7 in Figure 3). The saturated gas 7 at the working medium side outlet of the regenerator 6 is mixed with the gas-liquid two-phase fluid 10 at the outlet of the throttle valve 10 to the state 9 in FIG. Figure 3 State 11) The three fluids are mixed to Figure 3 State 8, flow through the first-stage throttle valve 5 and further throttle to Figure 3 State 12 and enter the evaporator 2, after absorbing heat and evaporating (as shown in Figure 3 State 1), being The first-stage compressor 3 sucks in and completes the heat pump cycle.

Step 4: Normal temperature water (as shown in state w1 in Figure 3) first flows into the heat exchange fluid side of the first stage condenser 4 to be heated to state w2 (w3) in Figure 3, and then flows into the heat exchange fluid side of the second stage condenser 9 to continue heating (as shown in state w4 in Figure 3), it is continuously heated to a medium-high temperature to obtain medium-high temperature hot water or high-temperature steam required by the process, and complete the continuous heating process of normal temperature water.

Embodiment 2: The heating and hot water heating pipelines are connected in parallel between the condenser and the regenerator to form a dual-stage compression dual-condenser intermediate throttling incomplete cooling heat pump dual-supply system. The system is shown in Figure 4.

The heat supply terminal 11 can be equipped with fan coils, floor coils, radiators and other heat supply terminals. The normal temperature heat exchange fluid at the outlet of the heat supply terminal 11 enters the heat exchange fluid side of the first-stage condenser 4 and is heated to a certain level for the first time. temperature, and then flows into the heat exchange fluid side of the regenerator 6, the return water at the heating end exchanges heat with the high-temperature working fluid flowing out of the first-stage compressor 3, the exhaust temperature of the first-stage compressor 3 decreases, and the heat-supply end The returned water is further heated and used for room heating to realize cascaded utilization of heat and reduce heat loss.

Embodiment 3: A medium-high temperature heat pump system with incomplete cooling of multiple condensers with three-stage and above compression and incomplete throttling.

This device can also be designed as a multi-stage compression multi-stage condenser intermediate throttling incomplete cooling medium and high temperature heat pump system according to specific implementation needs, so as to realize multiple heating of normal temperature water to produce higher temperature hot water or steam, so as to Better adapt to the requirements of different processes. Multi-stage compression, multi-stage condenser, middle throttling, incomplete cooling, and medium-high temperature heat pump system are shown in Figure 5.

The specific implementation is as follows:

Step 1: The first-stage compressor 3 sucks the low-temperature and low-pressure working fluid at the outlet of the working medium side of the evaporator 2, compresses it into a superheated gas with intermediate pressure, and then divides it into two paths. One way of overheated gas flows into the working medium side of the first-stage condenser 4, and the working medium in the condenser condenses and heats the normal temperature water to a certain temperature. Afterwards, the working fluid enters the first-stage throttle valve 5 to throttle and reduce pressure, and then enters the working medium side of the evaporator 2. After the working medium absorbs heat and evaporates, it is sucked by the first-stage compressor 3 .

Step 2: Another way of working fluid flowing out of the first-stage compressor 3 first enters the second-stage regenerator 6 for cooling on the working fluid side, and then enters the second-stage compressor 8 to be compressed into superheated gas, and the second-stage compression The fluid flowing out of the machine 8 is divided into two paths, one of which flows into the working fluid side of the second-stage condenser 9, and exchanges heat with the normal-temperature water flowing out of the heat-exchanging fluid side of the first-stage condenser 4, and the normal-temperature water is further heated. The heated normal temperature water enters the heat exchange fluid side of the third-stage condenser. The fluid flowing out from the working medium side of the second-stage condenser 9 is mixed with the gas-liquid two-phase fluid from the third stage, and then divided into two paths. All the way through the second-stage bypass throttle valve 7 throttling and reducing pressure, into a gas-liquid two-phase state. The gas-liquid two-phase fluid after throttling and depressurization exchanges heat with the superheated gas flowing out of the first-stage compressor 3 in the second-stage regenerator 6, the discharge temperature of the first-stage compressor decreases, and the gas-liquid two-phase fluid The phase fluid absorbs heat and evaporates into a saturated gaseous state. The other working medium flowing out from the second-stage condenser 9 flows through the second-stage throttling valve 11 to reduce pressure and become a gas-liquid two-phase state. After the above two paths of fluid are mixed with the fluid flowing out from the working medium side of the first-stage condenser 4, they flow through the first-stage throttling valve 5 to throttle. Another path of fluid flowing out from the second-stage compressor 8 enters the third-stage compressor.

The third step: the system starts from the 3rd level to the n-1th level and has the same structural form. To simplify the description, the i-th level is used to represent the 3rd level to the n-1th level. Another way of working fluid flowing out of the i-1th stage compressor first enters the i-stage regenerator 12 for cooling on the side of the heat exchange fluid, and then enters the i-stage compressor 13, and is compressed into superheated gas, and is discharged from the i-stage compressor The superheated gas flowing out of 13 is divided into two paths, one of which flows into the working medium side of the i-th stage condenser 15, and exchanges heat with the heat-exchanging fluid flowing out from the heat-exchanging fluid side of the i-1-th stage condenser, and the heat-exchanging fluid is further Heating, the heated normal temperature water enters the heat exchange fluid side of the i+1th stage condenser. The fluid flowing out from the working medium side of the i-th stage condenser 15 is mixed with the gas-liquid two-phase fluid from the i+1-th stage, and then divided into two paths. All the way flows through the i-th stage bypass throttle valve 14 to reduce the pressure and become a gas-liquid two-phase state. The gas-liquid two-phase fluid after throttling and depressurization exchanges heat with the superheated gas flowing out from the i-1th stage compressor in the i-stage regenerator 12, the discharge temperature of the i-1th stage compressor decreases, and the gas The liquid two-phase fluid absorbs heat and evaporates into a saturated gas state. Another path of working fluid flowing out from the working medium side of the i-stage condenser 15 flows through the i-stage throttling valve 16 to reduce pressure and become a gas-liquid two-phase state. After the above two fluids are mixed with the fluid flowing out from the working medium side of the i-1 stage condenser, they flow through the i-1 stage throttle valve to throttle. Another path of fluid flowing out from the i-th stage compressor 13 enters the i+1-th stage compressor to be compressed.

Step 4: Another fluid flowing out of the n-1 stage compressor enters the n-stage regenerator 18 for cooling on the working medium side, and then enters the n-stage compressor 19 to be compressed into superheated gas, and the n-stage compressor 19 flows out The superheated gas flows into the working medium side of the nth stage condenser 17, and exchanges heat with the heat exchange fluid flowing out from the heat exchange fluid side of the n-1th stage condenser, and the heat exchange fluid is heated for the last time.

Step 5: The fluid flowing out from the working medium side of the nth stage condenser 17 is divided into two paths, and one path flows through the nth stage bypass throttle valve 20 to reduce pressure and become a gas-liquid two-phase state. The gas-liquid two-phase fluid after throttling and depressurization exchanges heat with the superheated gas flowing out of the n-1th stage compressor in the n-stage regenerator 18, and the discharge temperature of the n-1st stage compressor decreases, The gas-liquid two-phase fluid absorbs heat and evaporates into a saturated gas state. Another path of working fluid flowing out from the working medium side of the n-th stage condenser 17 flows through the n-th stage throttle valve 10 to reduce the pressure and become a gas-liquid two-phase state. After the above two fluids are mixed, they enter the n-1th stage throttle valve to throttle.

Step 6: Normal temperature water flows into the condensers of each stage in turn, and after being continuously heated to a medium-high temperature, it flows out from the heat exchange fluid side of the n-th stage condenser 17 to obtain medium-high temperature hot water or high-temperature steam required by the process, completing the continuous normal-temperature water Heating process.

Although the preferred embodiments of the present invention have been described above in conjunction with the accompanying drawings, the present invention is not limited to the above-mentioned specific embodiments. The above-mentioned specific embodiments are only illustrative and not restrictive. Those of ordinary skill in the art Under the enlightenment of the present invention, people can also make many forms without departing from the purpose of the present invention and the scope of protection of the claims, and these all belong to the protection scope of the present invention.

Claims (2)

1. the not exclusively cooling moderate and high temperature heat system of throttling among a kind of more condensers of multi-stage compression, which is characterized in that the system 3≤i≤n-1, n >=4 in system；

First order compressor (3) outlet is connected with first order condenser (4) working medium side entrance, first order compressor (3) working medium side Outlet is connected with second level regenerator (6) overheat gas side entrance, and second level regenerator (6) overheats gas side outlet and compresses with the second level Machine (8) is connected, and first order condenser (4) working medium side outlet is connected with first order throttle valve (5) entrance, second level throttle valve (11) Outlet is connected with first order throttle valve (5) entrance, second level regenerator (6) two-phase fluid side outlet and first order throttle valve (5) Entrance is connected, and first order throttle valve (5) outlet is connected with evaporator (1) working medium side entrance, evaporator (1) working medium side outlet and the Stage compressor (3) entrance is connected；Second level condenser (9) working medium side outlet passes through setting second level bypass throttle valve (7) Piping connection second level regenerator (6)；

(i-1)-th stage compressor outlet is connected with i-stage regenerator (12) overheat gas side entrance, and i-stage regenerator (12) crosses hot gas Side outlet is connected with i-stage compressor (13) entrance, and i-stage compressor (13) outlet enters with i+1 grade regenerator overheat gas side Mouth is connected, and i-stage compressor (13) outlet is connected with i-stage condenser (15) working medium side entrance, i-stage condenser (15) working medium Side outlet is connect with i-stage throttle valve (16) entrance, and i+1 grade throttling valve outlet is connected with i-stage throttle valve (16) entrance, the I+1 grades of regenerator two-phase fluid side outlets are connected with i-stage throttle valve (16) entrance, i-stage throttle valve (16) outlet and (i-1)-th Grade throttling valve inlet is connected；I-stage condenser (15) working medium side outlet is connected with i-stage bypass throttle valve (14) entrance, i-stage Bypass throttle valve (14) outlet is connected with i-stage regenerator (12) two-phase fluid side entrance, i-stage regenerator (12) two-phase fluid Side outlet is connected with (i-1)-th grade of throttling valve inlet；

(n-1)th stage compressor outlet is connected with n-th grade of regenerator (18) overheat gas side entrance, and n-th grade of regenerator (18) crosses hot gas Side outlet is connected with n-th grade of compressor (19) entrance, and n-th grade of compressor (19) outlet enters with n-th grade of condenser (17) working medium side Mouth is connected, and n-th grade of condenser (17) working medium side outlet is connect with n-th grade of throttle valve (10) entrance, n-th grade of throttle valve (10) outlet It is connected with (n-1)th grade of throttling valve inlet；N-th grade of condenser (17) working medium side outlet and n-th grade of bypass throttle valve (20) entrance phase Even, n-th grade of bypass throttle valve (20) outlet is connected with n-th grade of regenerator (18) two-phase fluid side entrance, n-th grade of regenerator (18) Two-phase fluid side outlet is connected with (n-1)th grade of throttling valve inlet；

Normal-temperature water outlet is connected with first order condenser (4) heat exchanging fluid side entrance, and first order condenser (4) heat exchanging fluid side goes out Mouth is connected with second level condenser (9) heat exchanging fluid side entrance, and second level condenser (9) heat exchanging fluid side outlet and the third level are cold Condenser heat exchanging fluid side entrance is connected, i-stage condenser (15) heat exchanging fluid side outlet and i+1 grade condenser heat exchanging fluid side Entrance is connected, and (n-1)th grade of condenser heat exchanging fluid side entrance is connected with n-th grade of condenser (17) heat exchanging fluid side entrance, and n-th grade Condenser (17) heat exchanging fluid side outlet is connected with high temperature hot water or high-temperature steam entrance.

2. the not exclusively cooling moderate and high temperature heat system of throttling among the more condensers of multi-stage compression according to claim 1, It is characterized in that, the working medium used uses pure refrigerant, or uses CO₂/R1234zeE、CO₂/R1234zeZ、CO₂/R1234yf、 R41/R1234zeE, R41/R1234zeZ, R41/R1234yf, R32/R1234zeE, R32/R1234zeZ, R32/R1234yf are non- Azeotropic mixed working medium.