Natural cooling and vapor compression combined refrigerating system

Abstract

The utility model relates to a natural cooling and vapor compression combined refrigerating system which comprises a compressor, a condenser, a throttling element, an evaporator, a first liquid cooling loop and a second liquid cooling loop. The first cooling piece is connected to the first cooling liquid pipeline in series and used for cooling the first equipment, and the first cooling liquid pipeline exchanges heat with the evaporator. The second liquid cooling loop comprises a second circulating pump, a second cooling liquid pipeline, a second cooling piece and a dry cooler, the second cooling liquid pipeline is connected with the first cooling liquid pipeline through a flow dividing pipeline, and a first valve is arranged on the flow dividing pipeline. The system is provided with relatively independent cooling loops, and the dry cooler of one liquid cooling loop can dissipate heat by using air, so that the refrigeration load of a compressor is reduced, and the system efficiency is improved. Under the condition that the first liquid cooling loop breaks down, the first valve is opened, and cooling liquid in the second liquid cooling loop can be used for supplying cold temporarily.

Description

Technical Field

[0001] The utility model relates to the field of energy storage liquid cooling temperature control, and particularly relates to a natural cooling and vapor compression composite refrigeration system. Background Art

[0002] Most of the existing energy storage liquid cooling systems are vapor compression refrigeration systems, which provide a low-temperature cold source for the liquid cooling system through a vapor compression refrigeration cycle. Reference can be made to Figure 1 , which mainly includes a refrigeration system composed of a compressor 11, a condenser 12, an expansion valve 13, and an evaporator 14, and a first coolant circulation pipeline and a second coolant circulation pipeline that exchange heat with the evaporator 14. The first coolant circulation pipeline is connected to the liquid cooling plate of the battery (PCAK), which is denoted as the first liquid cooling plate 21. The second coolant circulation pipeline is connected to the liquid cooling plate of the converter (PCS), which is denoted as the second liquid cooling plate 22. The branch pipelines where the liquid cooling plates of the two are located are in a parallel relationship, and the coolant circulates under the action of the same circulation pump 5. An expansion tank 4 is also connected to the circulation pipeline through an expansion tank connecting pipe. This system still needs to start the compressor for refrigeration in low-temperature seasons, cannot make full use of natural cold sources, and has low energy utilization efficiency; the converter (PCS) of the energy storage system can withstand a relatively high working temperature, and supplying coolant at 40 - 50 °C can ensure normal operation. However, the existing energy storage liquid cooling system does not distinguish between cooling the converter (PCS) and the battery (PCAK), and uniformly supplies cooling at the lower temperature (about 18 - 20 °C) required for battery cooling, further reducing the system energy efficiency. Summary of the Utility Model

[0003] The purpose of the utility model is to provide a natural cooling and vapor compression composite refrigeration system to solve the problem of low energy efficiency existing in the existing refrigeration system.

[0004] To achieve the above purpose, the utility model adopts the following technical solutions:

[0005] A natural cooling and vapor compression composite refrigeration system includes a refrigeration circuit. The refrigeration circuit includes a compressor, a condenser, a throttling element, and an evaporator. The natural cooling and vapor compression composite refrigeration system also includes a first liquid cooling circuit and a second liquid cooling circuit. The first liquid cooling circuit includes a first circulation pump, a first coolant pipeline, and a first cooling member. The first cooling member is connected in series on the first coolant pipeline and is used to cool the first device. A section of the first coolant pipeline passes through the evaporator and exchanges heat with it;

[0006] The second liquid cooling circuit includes a second circulation pump, a second coolant pipeline, a second cooling component, and an air-cooled condenser. The second cooling component is connected in series to the second coolant pipeline and is used to cool the second device; the second coolant pipeline is connected to the first coolant pipeline through a shunt pipeline, and a first valve is provided on the shunt pipeline to control the on / off of the shunt pipeline.

[0007] Further, a first one-way valve is provided on the pipe section of the first coolant pipeline between the evaporator and the shunt pipeline.

[0008] Further, the natural cooling and vapor compression combined refrigeration system further includes an expansion tank. The expansion tank is connected to the first coolant pipeline through a first connecting pipe, and the expansion tank is connected to the second coolant pipeline through a second connecting pipe.

[0009] Further, a first filter and a second filter are respectively connected in series to the first coolant pipeline and the second coolant pipeline.

[0010] Further, a bypass pipe is connected in parallel to the pipe section where the air-cooled condenser is located, and a second valve is provided on the bypass pipe to adjust the magnitude of the bypass flow rate.

[0011] Further, the air-cooled condenser is arranged at the position of the condenser and shares a cooling fan with the condenser.

[0012] Further, the connection point of the shunt pipe to the second coolant pipeline is between the air-cooled condenser and the second cooling component, and a second one-way valve is provided on the second coolant pipeline between the air-cooled condenser and the connection point.

[0013] Further, an electric heater is also provided on the first coolant pipeline.

[0014] Further, the first cooling component is a first liquid cooling plate for a battery, and the second cooling component is a second liquid cooling plate for a converter.

[0015] Further, the refrigeration circuit further includes a liquid storage tank and a fluorine pump. The liquid storage tank and the fluorine pump are connected in series to the pipeline between the throttling component and the condenser. A third one-way valve is connected in parallel to the fluorine pump, and a fourth one-way valve is connected in parallel to the compressor.

[0016] Advantages of the present utility model:

[0017] (1) The utility model is a natural cooling and vapor compression composite refrigeration system, which sets relatively independent cooling circuits for two products that require liquid cooling, such as batteries and inverters. One of the liquid cooling circuits can use air heat dissipation all year round through a dry cooler, reducing the load of compressor refrigeration and improving system efficiency. For products such as inverters that do not require high coolant temperature, when the outdoor temperature is not very high, close the first valve connecting the two liquid cooling circuits, and only use natural air cooling. When the outdoor temperature is high, open the first valve to use the refrigeration system for auxiliary cooling. When the first liquid cooling circuit fails and cannot provide cooling, open the first valve, and the cooling problem can be temporarily solved by using the coolant in the second coolant pipeline, thereby improving the stability of the system.

[0018] (2) By installing an electric heater, the coolant can be heated and heated under necessary working conditions.

[0019] (3) In the conventional refrigeration circuit, adding components such as a liquid storage tank, a fluorine pump, and a one-way valve allows the compressor to be kept from turning on under low-temperature conditions. The natural cold source can be used for refrigeration through the fluorine pump circulation, shortening the compressor operation time and improving the system energy efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of a refrigeration system in the prior art;

[0021] Figure 2 This is the principle diagram of the natural cooling and steam compression compound refrigeration system of the utility model;

[0022] Figure 3 This is the operating principle diagram of the utility model natural cooling and steam compression composite refrigeration system under normal working conditions;

[0023] Figure 4 This is the operating principle diagram of the utility model natural cooling and vapor compression composite refrigeration system under outdoor high temperature conditions;

[0024] Figure 5 This is an operating principle diagram of the utility model natural cooling and vapor compression compound refrigeration system under partial circuit failure conditions;

[0025] Figure 6 This is the operating principle diagram of the utility model natural cooling and steam compression composite refrigeration system under heating conditions;

[0026] Figure 7 It is an operating principle diagram of the utility model natural cooling and steam compression composite refrigeration system under outdoor low temperature conditions.

[0027] 11. Compressor; 12. Condenser; 13. Expansion valve; 14. Evaporator; 15. Liquid storage tank; 16. Fluorine pump; 17. Third one-way valve; 18. Fourth one-way valve; 20. First coolant pipeline; 21. First liquid cooling plate; 22. First one-way valve; 23. First filter; 24. First circulation pump; 25. Electric heater; 30. Second coolant pipeline; 31. Second liquid cooling plate; 32. Second filter; 33. Second circulation pump; 34. Dry cooler; 35. Second valve; 36. Second one-way valve; 4. Expansion tank; 5. Circulation pump; 6. First valve. Detailed implementation manners

[0028] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art belong to the scope of protection of the present invention.

[0029] Embodiments of the present invention:

[0030] As Figure 2 shown, a natural cooling and vapor compression composite refrigeration system includes a refrigeration circuit. The refrigeration circuit includes a compressor 11, a condenser 12, a throttling element, and an evaporator 14. The outlet of the compressor 11 is connected to the condenser 12, and the expansion valve 13 is located between the condenser 12 and the evaporator 14. The throttling element used is the expansion valve 13, or a throttle valve. In other embodiments, a capillary tube may also be used. The principle of the above refrigeration circuit is prior art.

[0031] The refrigeration system further includes a first liquid cooling circuit and a second liquid cooling circuit. The first liquid cooling circuit includes a first circulation pump 24, a first coolant pipeline 20, and a first cooling element. The first circulation pump 24 is connected in series on the first coolant pipeline, and the first cooling element is connected in series on the first coolant pipeline and is used to cool a first device. In this embodiment, the first cooling element is the first liquid cooling plate 21 for a battery to dissipate heat from the battery. In other embodiments, this design concept can also be applied to the heat dissipation of other devices, and the cooling element may also be a liquid cooling pipe, and the liquid cooling pipe is distributed in a serpentine shape. One section of the first coolant pipeline passes through the evaporator 14 and exchanges heat with it to achieve the effect of cooling the coolant.

[0032] The second liquid cooling circuit includes a second circulation pump 33, a second coolant pipeline 30, a second cooling element, and a dry cooler 34. The second cooling element is connected in series on the second coolant pipeline 30 and is used to cool a second device. In this embodiment, the second cooling element is the second liquid cooling plate 31 for a converter to dissipate heat from the converter.

[0033] The second coolant pipeline 30 is connected to the first coolant pipeline through a shunt pipeline. A first valve 6 is provided on the shunt pipeline to control the on / off of the shunt pipeline, thereby controlling whether the coolant in the two pipelines circulates separately or is mixed; the first valve 6 is an electric ball valve.

[0034] A first one-way valve 22 is provided on the pipe section of the first coolant pipeline 20 between the evaporator 14 and the shunt pipeline.

[0035] The connection point of the shunt pipe with the second coolant pipeline is between the dry cooler 34 and the second liquid cooling plate 31. A second one-way valve 36 is provided on the second coolant pipeline 30 between the dry cooler 34 and this connection point to control the flow direction of the coolant.

[0036] The dry cooler 34 is arranged at the position of the condenser 12 and shares a cooling fan with the condenser 12.

[0037] A bypass pipe is connected in parallel to the pipe section where the dry cooler 34 is located. A second valve 35 is provided on the bypass pipe. The second valve 35 is used to adjust the bypass flow rate, thereby adjusting the coolant temperature. The second valve 35 is an electric ball valve.

[0038] An electric heater 25 is also provided on the first coolant pipeline 20, which is used in a low-temperature environment to heat the coolant in the pipeline.

[0039] The refrigeration system further includes an expansion tank 4. The expansion tank 4 is connected to the first coolant pipeline through a first connecting pipe, and the expansion tank 4 is connected to the second coolant pipeline 30 through a second connecting pipe. Under normal circumstances, the expansion tank 4 can play a role in stabilizing the pressure. In this embodiment, it can also adjust the distribution of the coolant and switch between the first coolant pipeline and the second coolant pipeline 30.

[0040] A first filter 23 and a second filter 32 are respectively connected in series on the first coolant pipeline 20 and the second coolant pipeline 30 to play a filtering role. The filters are not the improved part and are prior art.

[0041] The above is the basic composition and connection relationship of the natural cooling and vapor compression composite refrigeration system. The working principle will be described below, which is divided into several different working conditions.

[0042] (1) Conventional operating condition:

[0043] As Figure 3 shown, the refrigerant is pressurized and heated by the compressor 11, sent to the condenser 12 to exchange heat with the outdoor air, condensed and cooled to become a medium-temperature and high-pressure liquid refrigerant, enters the expansion valve 13, throttled and depressurized to become a low-temperature and low-pressure gas-liquid two-phase refrigerant, sent to the evaporator 14 to exchange heat with the coolant sent by the first circulation pump 24, becomes a low-temperature and low-pressure refrigerant vapor, and returns to the compressor 11 for the next cycle.

[0044] The coolant in the first liquid cooling circuit is cooled by the evaporator 14, passes through the electric heater 25 (not powered) and the first one-way valve 22, enters the first liquid cooling plate 21, heats up after exchanging heat with the battery, and returns to the first circulation pump 24 through the first filter 23 for the next cycle.

[0045] The coolant in the second liquid cooling circuit is sent to the dry cooler 34 by the second circulation pump 33, directly exchanges heat with the outdoor air, and after cooling, enters the second liquid cooling plate 31 through the second one-way valve 36, heats up after exchanging heat with the inverter, and returns to the second circulation pump 33 through the second filter for the next cycle.

[0046] Cooling loops are set for the battery and the inverter respectively. The second liquid cooling loop can use air to dissipate heat all year round through the dry cooler 34, reducing the load of compressor refrigeration and improving system efficiency. When the outdoor temperature is not very high, natural cooling by air is sufficient.

[0047] (2) Outdoor high temperature conditions:

[0048] like Figure 4 As shown, the refrigerant is pressurized and heated by the compressor 11, and is sent to the condenser 12 to exchange heat with the outdoor air, condensed and cooled to become medium-temperature and high-pressure liquid refrigerant, enters the expansion valve 13, throttled and reduced in pressure to become low-temperature and low-pressure gas-liquid two-phase refrigerant, sent to the evaporator 14 to exchange heat with the coolant sent by the first circulation pump 24, become low-temperature and low-pressure refrigerant vapor, and return to the compressor 11 for the next cycle.

[0049] The coolant in the first liquid cooling circuit is cooled by the evaporator 14, passes through the electric heater 25 (not powered) and the first one-way valve 22, and then is divided into two paths. One path enters the first liquid cooling plate 21, heats up after heat exchange with the battery, and returns to the first circulation pump 24 through the first filter 23 for the next cycle. The other path enters the second coolant pipeline 30 through the first valve 6, mixes with the coolant from the dry cooler 34, and solves the problem of high liquid supply temperature in the second coolant pipeline 30 under high outdoor temperature. The mixed coolant enters the second liquid cooling plate 31, heats up after heat exchange with the inverter, and returns to the second circulation pump 33 after passing through the second filter 32 for the next cycle, and the other part returns to the first coolant pipeline through the expansion tank 4 connecting pipe (first connecting pipe, second connecting pipe).

[0050] When the outdoor temperature is high, the dry cooler 34 is used to dissipate heat, and the compressor 11 refrigeration system is used to assist the second coolant pipe 30 in cooling, thereby meeting the cooling demand of the inverter.

[0051] (3) Failure condition of the second liquid cooling circuit:

[0052] like Figure 4As shown, the operating state of the refrigeration circuit of the compressor 11 is the same as that under normal operating conditions. The coolant in the first coolant pipeline is cooled by the evaporator 14, and then passes through the electric heater 25 (not powered on) and the first check valve 22, and is divided into two paths. One path enters the first liquid cooling plate 21, exchanges heat with the battery and then warms up, returns to the first circulation pump 24 through the first filter 23, and proceeds to the next cycle. The other path passes through the first valve 6 and enters the second coolant pipeline 30 to solve the problem of suspended cooling in case of a failure in the second coolant pipeline 30. The entering coolant can enter the second liquid cooling plate 31 and exchange heat with the converter, and then after warming up, returns to the first coolant pipeline through the second filter 32 and the expansion tank 4 connecting pipe, and enters the next cycle.

[0053] In the case where the first liquid cooling circuit cannot provide cooling, by opening the first valve 6, the coolant in the first coolant pipeline can be used to temporarily solve the cooling problem.

[0054] (4) Fault conditions of the first liquid cooling circuit or the compression refrigeration circuit:

[0055] As Figure 5 shown, the coolant in the second coolant pipeline 30 is cooled by the dry cooler 34, and then passes through the second check valve 36 and is divided into two paths. One path enters the second liquid cooling plate 31, exchanges heat with the converter and then warms up, returns to the second circulation pump 33 through the second filter 32, and proceeds to the next cycle. The other path passes through the first valve 6 and enters the first coolant pipeline 20 to solve the problem of suspended cooling in case of a fault in the first liquid cooling circuit or the compression refrigeration circuit. The coolant entering the first liquid cooling circuit enters the first liquid cooling plate 21, exchanges heat with the battery and then warms up, and returns to the second liquid cooling circuit through the first filter 23 and the expansion tank 4 connecting pipe.

[0056] The first liquid cooling circuit and the second liquid cooling circuit are connected by the first valve 6. In extreme operating conditions or when a device fails, by opening the first valve 6, abnormal conditions can be promptly addressed, improving the stability and reliability of the system.

[0057] (5) Heating condition:

[0058] As Figure 6 shown, the refrigeration circuit where the compressor 11 is located stops operating, and the second liquid cooling circuit stops operating.

[0059] The coolant in the first liquid cooling circuit passes through the evaporator 14, and then is heated and warmed up by the electric heater 25, enters the first liquid cooling plate 21 through the first check valve 22, exchanges heat with the battery and then cools down, passes through the first filter 23, and returns to the first circulation pump 24 to proceed to the next cycle.

[0060] (6) Outdoor low-temperature condition:

[0061] Figure 7As shown, the refrigeration circuit further includes a liquid storage tank 15 and a fluorine pump 16. The liquid storage tank 15 and the fluorine pump 16 are connected in series on the pipeline between the expansion valve 13 and the condenser 12. A third one-way valve 17 is connected in parallel to the fluorine pump 16, and a fourth one-way valve 18 is connected in parallel to the compressor 11. In the above description of this paragraph, for the convenience of understanding, Figures 1 to 5 the components such as the liquid storage tank 15, the fluorine pump 16, the third one-way valve 17, and the fourth one-way valve 18 are not shown. Of course, if the system is designed not to have the function under the (6) outdoor low-temperature working condition, these components may not be provided for the above (1) to (5) working conditions. After setting the liquid storage tank 15, the fluorine pump 16, the third one-way valve 17, and the fourth one-way valve 18, in the above (1) to (4) working conditions, the refrigerant enters the expansion valve 13 after passing through the third one-way valve 17.

[0062] Working principle of the outdoor low-temperature working condition:

[0063] In the refrigeration circuit, the refrigerant is sent into the condenser 12 through the fourth one-way valve 18 to exchange heat with the outdoor air, condenses and cools down to become a low-temperature and low-pressure liquid refrigerant and is stored in the liquid storage tank 15. Then it enters the expansion valve 13 after being pressurized by the fluorine pump 16, throttles and depressurizes to become a low-temperature and low-pressure liquid refrigerant, and is sent into the evaporator 14 to exchange heat with the coolant sent by the first circulation pump 24, becomes a low-temperature and low-pressure refrigerant vapor, and returns to the condenser 12 through the fourth one-way valve 18 for the next cycle.

[0064] Due to the addition of the fluorine pump 16 refrigeration mode, the compressor 11 is not turned on under the low-temperature working condition, and the natural cold source can be used for refrigeration through the circulation of the fluorine pump 16, shortening the running time of the compressor 11 and improving the energy efficiency of the system.

[0065] The coolant of the first liquid cooling circuit is cooled down through the evaporator 14, passes through the electric heater (not powered on) and the first one-way valve 22, enters the first liquid cooling plate 21, exchanges heat with the battery and then warms up, and returns to the first circulation pump 24 through the first filter 23 for the next cycle.

[0066] The coolant of the second liquid cooling circuit is sent into the dry cooler 34 by the second circulation pump 33 to directly exchange heat with the outdoor air. The second valve 35 automatically adjusts the opening according to the outlet water temperature to control the bypass flow rate, thereby controlling the outlet liquid temperature not to be lower than the dew condensation temperature. After cooling down, it enters the second liquid cooling plate 31 through the second one-way valve 36, exchanges heat with the converter and then warms up, and returns to the second circulation pump 33 through the second filter 32 for the next cycle.

[0067] The second valve 35 connected in parallel to the dry cooler 34 can control the supply liquid temperature of the second liquid cooling circuit not to be lower than the dew point temperature, without the need to achieve it by the way of electric heating to raise the temperature, reducing energy waste.

Claims

1. A natural cooling and vapor compression compound refrigeration system, comprising a refrigeration circuit, the refrigeration circuit comprising a compressor, a condenser, a throttling device, and an evaporator, characterized in that: The natural cooling and vapor compression compound refrigeration system also includes a first liquid cooling circuit and a second liquid cooling circuit. The first liquid cooling circuit includes a first circulation pump, a first coolant pipeline, and a first cooling element. The first cooling element is connected in series to the first coolant pipeline and is used to cool the first device. A section of the first coolant pipeline passes through the evaporator and performs heat exchange therewith. The second liquid cooling circuit includes a second circulation pump, a second coolant pipeline, a second cooling element, and a dry cooler. The second cooling element is connected in series to the second coolant pipeline and is used to cool the second equipment. The second coolant pipeline is connected to the first coolant pipeline through a shunt pipeline. The shunt pipeline is provided with a first valve for controlling the on-off of the shunt pipeline.

2. The natural cooling and vapor compression composite refrigeration system according to claim 1 is characterized in that: A first one-way valve is provided on the pipe section of the first coolant pipe between the evaporator and the diversion pipeline.

3. The natural cooling and vapor compression compound refrigeration system according to claim 2 is characterized in that: The natural cooling and vapor compression compound refrigeration system further comprises an expansion tank, which is connected to the first coolant pipeline via a first connecting pipe, and is connected to the second coolant pipeline via a second connecting pipe.

4. The natural cooling and vapor compression composite refrigeration system according to claim 1, characterized in that: The first coolant pipeline and the second coolant pipeline are respectively connected in series with a first filter and a second filter.

5. The natural cooling and vapor compression compound refrigeration system according to claim 1 is characterized in that: A bypass pipe is connected in parallel to the pipe section where the dry cooler is located. A second valve is provided on the bypass pipe. The second valve is used to adjust the bypass flow rate.

6. The natural cooling and vapor compression composite refrigeration system according to claim 1 or 5, characterized in that: The dry cooler is arranged at the position of the condenser and shares a heat dissipation fan with the condenser.

7. The natural cooling and vapor compression compound refrigeration system according to claim 2, characterized in that: The connection point between the shunt pipe and the second coolant pipeline is between the dry cooler and the second cooling element, and a second one-way valve is provided on the second coolant pipeline between the dry cooler and the connection point.

8. The natural cooling and vapor compression compound refrigeration system according to claim 1, characterized in that: The first coolant pipeline is also provided with an electric heater.

9. The natural cooling and vapor compression compound refrigeration system according to claim 1, characterized in that: The first cooling member is a first liquid cooling plate for the battery, and the second cooling member is a second liquid cooling plate for the inverter.

10. The natural cooling and vapor compression compound refrigeration system according to claim 1, characterized in that: The refrigeration circuit also includes a liquid storage tank and a fluorine pump, which are connected in series on the pipeline between the throttling device and the condenser. The fluorine pump is connected in parallel with a third one-way valve, and the compressor is connected in parallel with a fourth one-way valve.

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