Ultra-low temperature direct cooling temperature control system and battery testing equipment

Abstract

The present invention relates to the field of battery detection technology, and specifically discloses an ultra-low temperature direct cooling temperature control system and a battery detection device. The ultra-low temperature direct cooling temperature control system includes a primary refrigeration system and a secondary refrigeration system. The primary refrigeration system includes a first compressor, a first four-way valve, a first heat exchanger, a one-way valve assembly, a first electronic expansion valve, a second heat exchanger and a first gas-liquid separator. The secondary refrigeration system includes a second compressor, a second four-way valve, a second electronic expansion valve, a first solenoid valve, a circulation tank, a second solenoid valve, a circulation pump, a third solenoid valve and a second gas-liquid separator. By controlling the opening and closing of the first electronic expansion valve, the second electronic expansion valve, the first solenoid valve, the second solenoid valve and the third solenoid valve, it is possible to switch between direct cooling mode and direct heating mode. The ultra-low temperature direct cooling temperature control system has a wide range of applications, high heat exchange uniformity, and can overcome the problem of large pressure drop of the battery heat exchanger, thereby reducing the loss of cooling capacity.

Description

Technical Field

[0001] The present invention relates to the technical field of battery detection, and in particular to an ultra-low temperature direct cooling temperature control system and a battery detection device. Background Art

[0002] Refrigeration type ultra-low temperature equipment is mainly used in fields such as new energy battery testing. The low-temperature refrigerant is passed into the battery testing heat exchange plate through the refrigeration system to maintain a stable evaporation temperature to ensure a stable testing temperature environment.

[0003] Traditional refrigeration-type ultra-low temperature equipment uses a single-stage refrigeration system, which cannot achieve ultra-low temperature cooling at -45°C and has a limited scope of application. In addition, traditional refrigeration-type ultra-low temperature equipment directly passes the gas-liquid two-phase refrigerant after throttling by the throttle valve into the battery heat exchange plate for heat exchange with the battery heat exchange plate, which is prone to problems such as uneven battery heat exchange and difficulty in controlling overheating.

[0004] Therefore, it is urgent to propose an ultra-low temperature direct cooling temperature control system and a battery testing device to solve the above technical problems. Summary of the invention

[0005] According to one aspect of the present invention, the present invention provides an ultra-low temperature direct cooling temperature control system, which can provide a variety of detection temperature environments and has a wide range of applications. In addition, by pumping and pressurizing the battery heat exchanger to deliver pure liquid refrigerant, the heat exchange uniformity of the battery pack can be improved, and the problem of large pressure drop of the battery heat exchanger can be overcome, thereby reducing the loss of cooling capacity.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] The ultra-low temperature direct cooling temperature control system is used to provide a detection temperature environment for the battery pack, the battery pack includes a battery heat exchanger, and the ultra-low temperature direct cooling temperature control system includes:

[0008] A primary refrigeration system, comprising a first compressor, a first four-way valve, a first heat exchanger, a one-way valve assembly, a first electronic expansion valve, a second heat exchanger and a first gas-liquid separator; the outlet of the first compressor is communicated with the first port of the first four-way valve, the second port of the first four-way valve is communicated with the first port of the first heat exchanger, the second port of the first heat exchanger is communicated with the first interface of the one-way valve assembly, the second interface of the one-way valve assembly is communicated with one end of the first electronic expansion valve, the other end of the first electronic expansion valve is communicated with the fourth interface of the one-way valve assembly, the third interface of the one-way valve assembly is communicated with the first port of the second heat exchanger, the second port of the second heat exchanger is communicated with the fourth port of the first four-way valve, the third port of the first four-way valve is communicated with the inlet of the first gas-liquid separator, and the outlet of the first gas-liquid separator is communicated with the inlet of the first compressor; wherein the first port of the first heat exchanger is communicated with the second port, and the first port of the second heat exchanger is communicated with the second port;

[0009] A two-stage refrigeration system comprises a second compressor, a second four-way valve, a second electronic expansion valve, a first solenoid valve, a circulation tank, a second solenoid valve, a circulation pump, a third solenoid valve and a second gas-liquid separator; the outlet of the second compressor is communicated with the first port of the second four-way valve, the fourth port of the second four-way valve is communicated with the third port of the second heat exchanger, the fourth port of the second heat exchanger is communicated with one end of the second electronic expansion valve, the other end of the second electronic expansion valve is communicated with the inlet of the first solenoid valve, the outlet of the first solenoid valve is communicated with the inlet of the circulation tank, the gas outlet of the circulation tank is communicated with the inlet of the second solenoid valve, the outlet of the second solenoid valve is communicated with the The second port of the second four-way valve is connected, the third port of the second four-way valve is connected to the inlet of the second gas-liquid separator, and the outlet of the second gas-liquid separator is connected to the inlet of the second compressor; the liquid outlet of the circulation tank is connected to the inlet of the circulation pump, the outlet of the circulation pump is connected to the first port of the battery heat exchanger, and the second port of the battery heat exchanger is connected to the second port of the second four-way valve; the inlet of the third solenoid valve is connected to the first port of the battery heat exchanger, and the outlet of the third solenoid valve is connected to the other end of the second electronic expansion valve; wherein the third port of the second heat exchanger is connected to the fourth port, and the first port of the battery heat exchanger is connected to the second port.

[0010] Optionally, in the direct cooling mode, the first electronic expansion valve, the second electronic expansion valve, the first solenoid valve and the second solenoid valve are all opened, and the third solenoid valve is closed;

[0011] In the primary refrigeration system, the refrigerant discharged from the outlet of the first compressor enters the first heat exchanger through the first port and the second port of the first four-way valve to be condensed, the condensed refrigerant passes through the one-way valve assembly, the first electronic expansion valve and the one-way valve assembly in sequence and enters the second heat exchanger to absorb heat, the refrigerant after absorbing heat enters the first gas-liquid separator through the fourth port and the third port of the first four-way valve, and the gaseous refrigerant after gas-liquid separation returns to the first compressor;

[0012] In the two-stage refrigeration system, the refrigerant discharged from the outlet of the second compressor enters the second heat exchanger for heat exchange through the first port and the fourth port of the second four-way valve, the cooled refrigerant enters the circulation tank through the second electronic expansion valve and the first solenoid valve, the gaseous refrigerant in the circulation tank enters the second gas-liquid separator after passing through the second solenoid valve and the second port and the third port of the second four-way valve, the gaseous refrigerant after gas-liquid separation returns to the second compressor, the liquid refrigerant in the circulation tank enters the battery heat exchanger for heat exchange with the battery pack after being pressurized by the circulation pump, the refrigerant after heat exchange enters the second gas-liquid separator through the second port and the third port of the second four-way valve, and the gaseous refrigerant after gas-liquid separation returns to the second compressor.

[0013] Optionally, in direct heating mode, the first electronic expansion valve, the second electronic expansion valve and the third solenoid valve are all opened, and the first solenoid valve and the second solenoid valve are both closed;

[0014] In the primary refrigeration system, the refrigerant discharged from the outlet of the first compressor enters the second heat exchanger through the first port and the fourth port of the first four-way valve for condensation, the condensed refrigerant enters the first electronic expansion valve through the one-way valve assembly for throttling and then returns to the one-way valve assembly, and then enters the first heat exchanger through the one-way valve assembly for heat exchange, the heated refrigerant enters the first gas-liquid separator through the second port and the third port of the first four-way valve, and the gaseous refrigerant after gas-liquid separation returns to the first compressor;

[0015] In the two-stage refrigeration system, the refrigerant discharged from the outlet of the second compressor enters the battery heat exchanger through the first port and the second port of the second four-way valve for heat exchange, the cooled refrigerant passes through the third solenoid valve and enters the second electronic expansion valve for throttling, the throttled low-temperature refrigerant enters the second heat exchanger for heat exchange, the heated refrigerant enters the second gas-liquid separator through the fourth port and the third port of the second four-way valve, and the gaseous refrigerant after gas-liquid separation returns to the second compressor.

[0016] Optionally, the one-way valve assembly includes a first one-way valve group and a second one-way valve group arranged in parallel, the first one-way valve group includes a first one-way valve and a second one-way valve arranged in series, and the second one-way valve group includes a third one-way valve and a fourth one-way valve arranged in series; the second port of the first heat exchanger is connected to the inlet of the first one-way valve and the outlet of the second one-way valve, the first port of the second heat exchanger is connected to the inlet of the third one-way valve and the outlet of the fourth one-way valve, the outlet of the first one-way valve and the outlet of the third one-way valve are connected to the first port of the first electronic expansion valve, and the inlet of the second one-way valve and the inlet of the fourth one-way valve are connected to the second port of the first electronic expansion valve.

[0017] Optionally, the primary refrigeration system further includes a first filter, and the one-way valve assembly is connected to the first electronic expansion valve through the first filter.

[0018] Optionally, the two-stage refrigeration system further includes a second filter, and the second heat exchanger and the second electronic expansion valve are connected through the second filter.

[0019] Optionally, the two-stage refrigeration system further includes a third filter, and the second electronic expansion valve is connected to the third solenoid valve through the third filter.

[0020] Optionally, the secondary refrigeration system further includes a fifth one-way valve, the outlet of the circulation pump is connected to the inlet of the fifth one-way valve, and the outlet of the fifth one-way valve is connected to the first port of the battery heat exchanger.

[0021] Optionally, the gas outlet is arranged at the top of the circulation tank, and the liquid outlet is arranged at the bottom of the circulation tank.

[0022] According to another aspect of the present invention, the present invention further provides a battery testing device, comprising the ultra-low temperature direct cooling temperature control system described in any of the above technical solutions.

[0023] The beneficial effects of the present invention are:

[0024] The present invention provides an ultra-low temperature direct cooling temperature control system, including a primary refrigeration system and a secondary refrigeration system. The primary refrigeration system includes a first compressor, a first four-way valve, a first heat exchanger, a one-way valve assembly, a first electronic expansion valve, a second heat exchanger and a first gas-liquid separator; the secondary refrigeration system includes a second compressor, a second four-way valve, a second electronic expansion valve, a first solenoid valve, a circulation tank, a second solenoid valve, a circulation pump, a third solenoid valve and a second gas-liquid separator. By controlling the opening and closing of the first electronic expansion valve, the second electronic expansion valve, the first solenoid valve, the second solenoid valve and the third solenoid valve, cooling and heating at different temperatures can be achieved to meet the requirements of battery detection equipment for different detection temperatures, and the system has wide universality.

[0025] By setting up a circulation tank, the refrigerant delivered to the battery heat exchanger by the circulation pump is a pure liquid refrigerant. The liquid refrigerant can better exchange heat with the battery pack. Compared with the prior art of using a gas-liquid mixed refrigerant to exchange heat with the battery pack, the heat exchange rate in the same time is greater, the heat exchange efficiency is improved, and the heat exchange uniformity is improved. In addition, by delivering liquid refrigerant through a circulation pump, the problem of large pressure drop of the battery heat exchanger can be overcome, the loss of cold capacity can be reduced, and the energy utilization efficiency can be improved.

[0026] The present invention also provides a battery testing device, comprising the ultra-low temperature direct cooling temperature control system. Since the battery testing device adopts the ultra-low temperature direct cooling temperature control system, the accuracy of the test result is relatively high. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A schematic diagram of an ultra-low temperature direct cooling temperature control system provided in an embodiment of the present invention.

[0028] In the figure:

[0029] 100. Battery heat exchanger;

[0030] 11. first compressor; 12. first four-way valve; 13. first heat exchanger; 14. one-way valve assembly; 141. first one-way valve; 142. second one-way valve; 143. third one-way valve; 144. fourth one-way valve; 15. first electronic expansion valve; 16. second heat exchanger; 17. first gas-liquid separator; 18. first filter;

[0031] 21. Second compressor; 201. Second filter; 202. Third filter; 203. Fifth one-way valve; 22. Second four-way valve; 23. Second electronic expansion valve; 24. First solenoid valve; 25. Circulation tank; 26. Second solenoid valve; 27. Circulation pump; 28. Third solenoid valve; 29. ​​Second gas-liquid separator. DETAILED DESCRIPTION

[0032] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] In the description of the present invention, it should be noted that the orientations or positional relationships indicated by the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. Among them, the terms "first position" and "second position" are two different positions, and the first feature "above", "above" and "above" the second feature include the first feature being directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. The first feature "below", "below" and "below" the second feature include the first feature being directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0034] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0035] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0036] This embodiment provides an ultra-low temperature direct cooling temperature control system, which can provide a variety of detection temperature environments and has a wide range of applications. In addition, by pumping the battery heat exchanger to deliver pure liquid refrigerant, the heat exchange uniformity of the battery pack can be improved, and the problem of large pressure drop of the battery heat exchanger can be overcome, thereby reducing the loss of cooling capacity.

[0037] like Figure 1 As shown, the ultra-low temperature direct cooling temperature control system is used to provide a detection temperature environment for a battery pack, and the battery pack includes a battery heat exchanger 100. Specifically, the ultra-low temperature direct cooling temperature control system includes a primary refrigeration system and a secondary refrigeration system.

[0038] The primary refrigeration system includes a first compressor 11 , a first four-way valve 12 , a first heat exchanger 13 , a one-way valve assembly 14 , a first electronic expansion valve 15 , a second heat exchanger 16 and a first gas-liquid separator 17 .

[0039] The connection between the various parts in the primary refrigeration system is as follows:

[0040] The outlet of the first compressor 11 is connected to the first port a of the first four-way valve 12, the second port b of the first four-way valve 12 is connected to the first port a of the first heat exchanger 13, the second port b of the first heat exchanger 13 is connected to the first interface a of the one-way valve assembly 14, the second interface b of the one-way valve assembly 14 is connected to one end of the first electronic expansion valve 15, the other end of the first electronic expansion valve 15 is connected to the fourth interface d of the one-way valve assembly 14, the third interface c of the one-way valve assembly 14 is connected to the first port a of the second heat exchanger 16, the second port b of the second heat exchanger 16 is connected to the fourth port d of the first four-way valve 12, the third port c of the first four-way valve 12 is connected to the inlet of the first gas-liquid separator 17, and the outlet of the first gas-liquid separator 17 is connected to the inlet of the first compressor 11.

[0041] The first port a of the first heat exchanger 13 is connected to the second port b, and the first port a of the second heat exchanger 16 is connected to the second port b.

[0042] The secondary refrigeration system includes a second compressor 21 , a second four-way valve 22 , a second electronic expansion valve 23 , a first solenoid valve 24 , a circulation tank 25 , a second solenoid valve 26 , a circulation pump 27 , a third solenoid valve 28 and a second gas-liquid separator 29 .

[0043] The connections between the various parts in the two-stage refrigeration system are as follows:

[0044] The outlet of the second compressor 21 is connected to the first port a of the second four-way valve 22, the fourth port d of the second four-way valve 22 is connected to the third port c of the second heat exchanger 16, the fourth port d of the second heat exchanger 16 is connected to one end of the second electronic expansion valve 23, the other end of the second electronic expansion valve 23 is connected to the inlet of the first solenoid valve 24, the outlet of the first solenoid valve 24 is connected to the inlet of the circulation tank 25, the gas outlet of the circulation tank 25 is connected to the inlet of the second solenoid valve 26, the outlet of the second solenoid valve 26 is connected to the second port b of the second four-way valve 22, and the gas outlet of the circulation tank 25 is connected to the inlet of the second solenoid valve 26. The third port c of the second four-way valve 22 is connected to the inlet of the second gas-liquid separator 29, and the outlet of the second gas-liquid separator 29 is connected to the inlet of the second compressor 21; the liquid outlet of the circulation tank 25 is connected to the inlet of the circulation pump 27, and the outlet of the circulation pump 27 is connected to the first port a of the battery heat exchanger 100, and the second port b of the battery heat exchanger 100 is connected to the second port b of the second four-way valve 22; the inlet of the third solenoid valve 28 is connected to the first port a of the battery heat exchanger 100, and the outlet of the third solenoid valve 28 is connected to the other end of the second electronic expansion valve 23.

[0045] The third port c of the second heat exchanger 16 is connected to the fourth port d, and the first port a of the battery heat exchanger 100 is connected to the second port b.

[0046] The ultra-low temperature direct cooling temperature control system provided in this embodiment can realize cooling and heating at different temperatures by controlling the opening and closing of the first electronic expansion valve 15, the second electronic expansion valve 23, the first solenoid valve 24, the second solenoid valve 26 and the third solenoid valve 28, so as to meet the requirements of the battery detection equipment for different detection temperatures, and has wide universality. In addition, by setting the circulation tank 25, the refrigerant delivered to the battery heat exchanger 100 by the circulation pump 27 is a pure liquid refrigerant, and the liquid refrigerant can better exchange heat with the battery pack. Compared with the use of gas-liquid mixed refrigerant and battery pack heat exchange in the prior art, the heat exchange rate in the same time is greater, the heat exchange efficiency is improved, and the heat exchange uniformity is improved. In addition, by delivering liquid refrigerant through the circulation pump 27, the problem of large pressure drop of the electromagnetic heat exchanger can be overcome, the loss of cold capacity can be reduced, and the energy utilization efficiency can be improved.

[0047] Optionally, in this embodiment, the ultra-low temperature direct cooling temperature control system includes a direct cooling mode and a direct heating mode.

[0048] Specifically, see Figure 1 In the direct cooling mode, the first electronic expansion valve 15, the second electronic expansion valve 23, the first solenoid valve 24 and the second solenoid valve 26 are all opened, and the third solenoid valve 28 is closed.

[0049] At this time, in the primary refrigeration system, the high-temperature and high-pressure gaseous refrigerant discharged from the outlet of the first compressor 11 enters the first heat exchanger 13 through the first port a and the second port b of the first four-way valve 12 for condensation, and the condensed refrigerant enters the first electronic expansion valve 15 for throttling through the one-way valve assembly 14 in turn. The low-temperature and low-pressure refrigerant that is throttled into a gas-liquid two-phase enters the one-way valve assembly 14 again, and enters the second heat exchanger 16 after passing through the one-way valve assembly 14 to absorb heat. The refrigerant after absorbing heat enters the first gas-liquid separator 17 through the fourth port d and the third port c of the first four-way valve 12, and the gaseous refrigerant after gas-liquid separation returns to the first compressor 11, thereby forming a primary refrigeration cycle.

[0050] In the two-stage refrigeration system, the refrigerant discharged from the outlet of the second compressor 21 enters the second heat exchanger 16 through the first port a and the fourth port d of the second four-way valve 22 for heat exchange, and the cooled refrigerant enters the circulation tank 25 through the second electronic expansion valve 23 and the first solenoid valve 24. The gaseous refrigerant in the circulation tank 25 enters the second gas-liquid separator 29 through the second solenoid valve 26 and the second port b and the third port c of the second four-way valve 22, and the gaseous refrigerant after gas-liquid separation returns to the second compressor 21; the liquid refrigerant in the circulation tank 25 enters the battery heat exchanger 100 after being pressurized by the circulation pump 27 to exchange heat with the battery pack, and the refrigerant after heat exchange enters the second gas-liquid separator 29 through the second port b and the third port c of the second four-way valve 22, and the gaseous refrigerant after gas-liquid separation returns to the second compressor 21.

[0051] In direct cooling mode, the primary refrigeration system and the secondary refrigeration system jointly provide cooling for the battery pack, which can achieve ultra-low temperature cooling below -45°C and has a wide range of applications.

[0052] It is worth mentioning that if the cooling temperature requirement is not high, only the secondary refrigeration system can be started.

[0053] Continue to see Figure 1 In the direct heating mode, the first electronic expansion valve 15, the second electronic expansion valve 23 and the third solenoid valve 28 are all opened, and the first solenoid valve 24 and the second solenoid valve 26 are all closed.

[0054] At this time, in the primary refrigeration system, the high-temperature and high-pressure gaseous refrigerant discharged from the outlet of the first compressor 11 enters the second heat exchanger 16 through the first port a and the fourth port d of the first four-way valve 12 for condensation, the condensed refrigerant enters the first electronic expansion valve 15 through the one-way valve assembly 14 for throttling and then returns to the one-way valve assembly 14, and then enters the first heat exchanger 13 through the one-way valve assembly 14 for heat exchange, the heated refrigerant enters the first gas-liquid separator 17 through the second port b and the third port c of the first four-way valve 12, and the gaseous refrigerant after gas-liquid separation returns to the first compressor 11.

[0055] In the two-stage refrigeration system, the refrigerant discharged from the outlet of the second compressor 21 enters the battery heat exchanger 100 for heat exchange through the first port a and the second port b of the second four-way valve 22, the cooled refrigerant passes through the third solenoid valve 28 and enters the second electronic expansion valve 23 for throttling, the throttled low-temperature refrigerant enters the second heat exchanger 16 for heat exchange, the heated refrigerant enters the second gas-liquid separator 29 through the fourth port d and the third port c of the second four-way valve 22, and the gaseous refrigerant after gas-liquid separation returns to the second compressor 21.

[0056] In direct heating mode, the primary refrigeration system and the secondary refrigeration system jointly provide heat for the battery pack, which has a wide range of uses.

[0057] It is worth mentioning that if the heating temperature requirement is not high, only the secondary refrigeration system can be started.

[0058] Further, see Figure 1 The one-way valve assembly 14 includes a first one-way valve group and a second one-way valve group arranged in parallel, the first one-way valve group includes a first one-way valve 141 and a second one-way valve 142 arranged in series, and the second one-way valve group includes a third one-way valve 143 and a fourth one-way valve 144 arranged in series. Specifically, the second port b of the first heat exchanger 13 is connected to the inlet of the first one-way valve 141 and the outlet of the second one-way valve 142, the first port a of the second heat exchanger 16 is connected to the inlet of the third one-way valve 143 and the outlet of the fourth one-way valve 144, the outlet of the first one-way valve 141 and the outlet of the third one-way valve 143 are connected to the first port a of the first electronic expansion valve 15, and the inlet of the second one-way valve 142 and the inlet of the fourth one-way valve 144 are connected to the second port b of the first electronic expansion valve 15.

[0059] It is worth noting that, in this embodiment, the first port a of the one-way valve assembly 14 is located at the connection between the inlet of the first one-way valve 141 and the outlet of the second one-way valve 142. The second port b of the one-way valve assembly 14 is located at the connection between the outlet of the first one-way valve 141 and the outlet of the third one-way valve 143. The third port c of the one-way valve assembly 14 is located at the connection between the inlet of the third one-way valve 143 and the outlet of the fourth one-way valve 144. The fourth port d of the one-way valve assembly 14 is located at the connection between the inlet of the second one-way valve 142 and the inlet of the fourth one-way valve 144.

[0060] Optionally, continue to see Figure 1 The primary refrigeration system further includes a first filter 18, and the one-way valve assembly 14 is connected to the first electronic expansion valve 15 through the first filter 18. Specifically, in this embodiment, the second interface b of the one-way valve assembly 14 is connected to the first port a of the first filter 18, and the second port b of the first filter 18 is connected to the first port a of the first electronic expansion valve 15. By providing the first filter 18, the refrigerant can be filtered.

[0061] Optionally, continue to see Figure 1 The two-stage refrigeration system further includes a second filter 201, and the second heat exchanger 16 and the second electronic expansion valve 23 are connected through the second filter 201. Specifically, in this embodiment, the fourth port d of the second heat exchanger 16 is connected to the first port a of the second filter 201, and the second port b of the second filter 201 is connected to the second electronic expansion valve 23. By providing the second filter 201, the refrigerant entering the circulation tank 25 can be filtered during cooling.

[0062] Optionally, continue to see Figure 1 The two-stage refrigeration system further includes a third filter 202, and the second electronic expansion valve 23 is connected to the third solenoid valve 28 through the third filter 202. Specifically, the outlet of the third solenoid valve 28 is connected to the first port a of the third filter 202, and the second port b of the third filter 202 is connected to the second electronic expansion valve 23. By providing the third filter 202, the refrigerant can be filtered during heating.

[0063] Further, see Figure 1 The secondary refrigeration system further includes a fifth one-way valve 203, the outlet of the circulation pump 27 is connected to the inlet of the fifth one-way valve 203, and the outlet of the fifth one-way valve 203 is connected to the first port a of the battery heat exchanger 100. By providing the fifth one-way valve 203, the refrigerant in the battery heat exchanger 100 can be prevented from flowing to the liquid storage tank during heating, thereby improving the reliability of heating.

[0064] Optionally, the gas outlet is arranged at the top of the circulation tank 25, and the liquid outlet is arranged at the bottom of the circulation tank 25. Since the gas is lighter than the liquid, the gas will gather at the upper part and the liquid will gather at the lower part in the circulation tank 25. Therefore, the gas outlet is arranged at the top of the circulation tank 25 and the liquid outlet is arranged at the bottom of the circulation tank 25, so that the gas and liquid can flow out smoothly, the smoothness of the refrigerant flow is improved, and the temperature control reliability of the ultra-low temperature direct cooling temperature control system is improved.

[0065] This embodiment also provides a battery testing device, including the above-mentioned ultra-low temperature direct cooling temperature control system.

[0066] Since the battery testing equipment adopts the above-mentioned ultra-low temperature direct cooling temperature control system, the accuracy of the test results is relatively high.

[0067] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. An ultra-low temperature direct cooling temperature control system, used for providing a detection temperature environment for a battery pack, wherein the battery pack comprises a battery heat exchanger (100), characterized in that: The ultra-low temperature direct cooling temperature control system comprises: A primary refrigeration system comprises a first compressor (11), a first four-way valve (12), a first heat exchanger (13), a one-way valve assembly (14), a first electronic expansion valve (15), a second heat exchanger (16) and a first gas-liquid separator (17); the outlet of the first compressor (11) is connected to the first port of the first four-way valve (12), the second port of the first four-way valve (12) is connected to the first port of the first heat exchanger (13), the second port of the first heat exchanger (13) is connected to the first interface of the one-way valve assembly (14), the second interface of the one-way valve assembly (14) is connected to one end of the first electronic expansion valve (15), and the The other end of the first electronic expansion valve (15) is in communication with the fourth interface of the one-way valve assembly (14), the third interface of the one-way valve assembly (14) is in communication with the first port of the second heat exchanger (16), the second port of the second heat exchanger (16) is in communication with the fourth port of the first four-way valve (12), the third port of the first four-way valve (12) is in communication with the inlet of the first gas-liquid separator (17), and the outlet of the first gas-liquid separator (17) is in communication with the inlet of the first compressor (11); wherein the first port of the first heat exchanger (13) is in communication with the second port, and the first port of the second heat exchanger (16) is in communication with the second port; A two-stage refrigeration system comprises a second compressor (21), a second four-way valve (22), a second electronic expansion valve (23), a first solenoid valve (24), a circulation tank (25), a second solenoid valve (26), a circulation pump (27), a third solenoid valve (28) and a second gas-liquid separator (29); the outlet of the second compressor (21) is connected to the first port of the second four-way valve (22), the fourth port of the second four-way valve (22) is connected to the third port of the second heat exchanger (16), the fourth port of the second heat exchanger (16) is connected to one end of the second electronic expansion valve (23), the other end of the second electronic expansion valve (23) is connected to the inlet of the first solenoid valve (24), the outlet of the first solenoid valve (24) is connected to the inlet of the circulation tank (25), the gas outlet of the circulation tank (25) is connected to the inlet of the second solenoid valve (26), the second solenoid valve (26) is connected to the third port of the second heat exchanger (16), the fourth port of the second heat exchanger (16) is connected to one end of the second electronic expansion valve (23), the other end of the second electronic expansion valve (23) is connected to the inlet of the first solenoid valve (24), the outlet of the first solenoid valve (24) is connected to the inlet of the circulation tank (25), the gas outlet of the circulation tank (25) is connected to the inlet of the second solenoid valve (26), the gas outlet of the second solenoid valve (26) is connected to the inlet of the second solenoid valve (26), and the gas outlet of the circulation tank (25) is connected to the inlet of the second solenoid valve (26). The outlet of the second solenoid valve (26) is connected to the second port of the second four-way valve (22), the third port of the second four-way valve (22) is connected to the inlet of the second gas-liquid separator (29), and the outlet of the second gas-liquid separator (29) is connected to the inlet of the second compressor (21); the liquid outlet of the circulation tank (25) is connected to the inlet of the circulation pump (27), the outlet of the circulation pump (27) is connected to the first port of the battery heat exchanger (100), and the second port of the battery heat exchanger (100) is connected to the second port of the second four-way valve (22); the inlet of the third solenoid valve (28) is connected to the first port of the battery heat exchanger (100), and the outlet of the third solenoid valve (28) is connected to the other end of the second electronic expansion valve (23); wherein the third port of the second heat exchanger (16) is connected to the fourth port, and the first port of the battery heat exchanger (100) is connected to the second port; In the direct heating mode, the first electronic expansion valve (15), the second electronic expansion valve (23) and the third solenoid valve (28) are all opened, and the first solenoid valve (24) and the second solenoid valve (26) are all closed; In the primary refrigeration system, the refrigerant discharged from the outlet of the first compressor (11) enters the second heat exchanger (16) through the first port and the fourth port of the first four-way valve (12) to be condensed, the condensed refrigerant enters the first electronic expansion valve (15) through the one-way valve assembly (14) to be throttled and then returns to the one-way valve assembly (14), and then enters the first heat exchanger (13) through the one-way valve assembly (14) to exchange heat, the heated refrigerant enters the first gas-liquid separator (17) through the second port and the third port of the first four-way valve (12), and the gaseous refrigerant after gas-liquid separation returns to the first compressor (11); In the two-stage refrigeration system, the refrigerant discharged from the outlet of the second compressor (21) enters the battery heat exchanger (100) through the first port and the second port of the second four-way valve (22) for heat exchange, the cooled refrigerant passes through the third solenoid valve (28) and enters the second electronic expansion valve (23) for throttling, the throttled low-temperature refrigerant enters the second heat exchanger (16) for heat exchange, the heated refrigerant enters the second gas-liquid separator (29) through the fourth port and the third port of the second four-way valve (22), and the gaseous refrigerant after gas-liquid separation returns to the second compressor (21).

2. The ultra-low temperature direct cooling temperature control system according to claim 1, characterized in that: In the direct cooling mode, the first electronic expansion valve (15), the second electronic expansion valve (23), the first solenoid valve (24) and the second solenoid valve (26) are all opened, and the third solenoid valve (28) is closed; In the primary refrigeration system, the refrigerant discharged from the outlet of the first compressor (11) enters the first heat exchanger (13) through the first port and the second port of the first four-way valve (12) to be condensed, the condensed refrigerant passes through the one-way valve assembly (14), the first electronic expansion valve (15) and the one-way valve assembly (14) in sequence and then enters the second heat exchanger (16) to absorb heat, the refrigerant after absorbing heat enters the first gas-liquid separator (17) through the fourth port and the third port of the first four-way valve (12), and the gaseous refrigerant after gas-liquid separation returns to the first compressor (11); In the two-stage refrigeration system, the refrigerant discharged from the outlet of the second compressor (21) enters the second heat exchanger (16) through the first port and the fourth port of the second four-way valve (22) for heat exchange. The cooled refrigerant enters the circulation tank (25) through the second electronic expansion valve (23) and the first solenoid valve (24). The gaseous refrigerant in the circulation tank (25) enters the second gas-liquid separator (29) after passing through the second solenoid valve (26) and the second port and the third port of the second four-way valve (22). The gaseous refrigerant after gas-liquid separation returns to the second compressor (21). The liquid refrigerant in the circulation tank (25) enters the battery heat exchanger (100) after being pressurized by the circulation pump (27) to exchange heat with the battery pack. The refrigerant after heat exchange enters the second gas-liquid separator (29) through the second port and the third port of the second four-way valve (22). The gaseous refrigerant after gas-liquid separation returns to the second compressor (21).

3. The ultra-low temperature direct cooling temperature control system according to claim 1, characterized in that: The one-way valve assembly (14) comprises a first one-way valve group and a second one-way valve group arranged in parallel, the first one-way valve group comprises a first one-way valve (141) and a second one-way valve (142) arranged in series, and the second one-way valve group comprises a third one-way valve (143) and a fourth one-way valve (144) arranged in series; the second port of the first heat exchanger (13) is connected to the inlet of the first one-way valve (141) and the outlet of the second one-way valve (142), the first port of the second heat exchanger (16) is connected to the inlet of the third one-way valve (143) and the outlet of the fourth one-way valve (144), the outlet of the first one-way valve (141) and the outlet of the third one-way valve (143) are connected to the first port of the first electronic expansion valve (15), and the inlet of the second one-way valve (142) and the inlet of the fourth one-way valve (144) are connected to the second port of the first electronic expansion valve (15).

4. The ultra-low temperature direct cooling temperature control system according to claim 1, characterized in that: The primary refrigeration system further comprises a first filter (18), and the one-way valve assembly (14) is connected to the first electronic expansion valve (15) via the first filter (18).

5. The ultra-low temperature direct cooling temperature control system according to any one of claims 1 to 4, characterized in that: The two-stage refrigeration system further comprises a second filter (201), and the second heat exchanger (16) and the second electronic expansion valve (23) are connected via the second filter (201).

6. The ultra-low temperature direct cooling temperature control system according to claim 5, characterized in that: The two-stage refrigeration system further comprises a third filter (202), and the second electronic expansion valve (23) is connected to the third solenoid valve (28) through the third filter (202).

7. The ultra-low temperature direct cooling temperature control system according to any one of claims 1 to 4, characterized in that: The secondary refrigeration system further includes a fifth one-way valve (203), the outlet of the circulation pump (27) is connected to the inlet of the fifth one-way valve (203), and the outlet of the fifth one-way valve (203) is connected to the first port of the battery heat exchanger (100).

8. The ultra-low temperature direct cooling temperature control system according to any one of claims 1 to 4, characterized in that: The gas outlet is arranged at the top of the circulation tank (25), and the liquid outlet is arranged at the bottom of the circulation tank (25).

9. Battery testing equipment, characterized in that, An ultra-low temperature direct cooling temperature control system comprising any one of claims 1-8.

Images