Multi-loop liquid cooling system for liquid cooling unit

Abstract

The invention provides a multi-loop liquid cooling system for a liquid cooling unit. The multi-loop liquid cooling system comprises a refrigerating device, a first water pump, an electric valve and a three-way regulating valve, the battery and the converter are arranged in parallel, the first heat exchanger is connected with a cold plate pipeline of the battery through a first circulating pipeline, and the first heat exchanger is connected with a cold plate pipeline of the converter through a second circulating pipeline; the first water pump is connected in series between the cold plate of the battery and the first heat exchanger; the output end of the first water pump is also connected with one end of the electric valve; the first input end and the output end of the three-way regulating valve are connected in series between the cold plate of the converter and the first heat exchanger, and the second input end of the three-way regulating valve is also connected with the other end of the electric valve. When the environment temperature is larger than a first temperature threshold value, the first water pump operates, and the refrigerating device provides different refrigerating fluid temperatures for the battery and the converter through the first circulating pipeline and the second circulating pipeline so as to conduct graded refrigerating heat exchange. The comprehensive energy efficiency of the liquid cooling unit can be improved, and the energy consumption is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of liquid cooling units, and more specifically, to a multi-circuit liquid cooling system for a liquid cooling unit. Background Art

[0002] Energy storage has been widely used in the power supply side, grid side, user side, centralized renewable energy grid connection, ancillary services and other fields. It has important practical significance for energy conservation and emission reduction, reliability improvement, power quality improvement, renewable energy penetration rate increase and revenue appreciation.

[0003] At present, the cooling of batteries is mainly air-cooled, but air-cooled heat dissipation has problems such as low heat dissipation efficiency of battery packs, high system noise, and poor environmental adaptability of products, which brings challenges to the promotion and application of energy storage systems. The liquid cooling system has the advantages of high heat transfer coefficient, large specific heat capacity, and fast cooling speed. Liquid cooling has become the mainstream of battery thermal management; secondly, with the advancement of technology, the air-cooled power conversion system (PCS) currently used has also been upgraded to liquid cooling to improve efficiency and service life. The existing outdoor cabinet liquid cooling system generally provides cooling for the converter PCS and batteries in series, but the operating temperature range of the battery and the operating temperature range of the PCS are quite different. The series connection method is prone to high energy consumption, which puts higher requirements on the liquid cooling unit. Therefore, it is of great significance to efficiently cool and heat the battery and PCS with multiple circuits to improve the comprehensive energy efficiency of the liquid cooling unit. Summary of the invention

[0004] The present invention provides a multi-circuit liquid cooling system for a liquid cooling unit, which solves the problem that the existing liquid cooling unit has no classification for cooling batteries and converters, has high energy consumption and is not energy-saving, and can improve the comprehensive energy efficiency of the liquid cooling unit throughout the year and reduce energy consumption.

[0005] To achieve the above objectives, the present invention provides the following technical solutions:

[0006] A multi-circuit liquid cooling system for a liquid cooling unit, comprising: a refrigeration device, a first water pump, an electric valve and a three-way regulating valve;

[0007] The battery and the converter are arranged in parallel at two ends of the first heat exchanger in the refrigeration device;

[0008] The first heat exchanger of the refrigeration device is connected to the cold plate pipeline of the battery through a first circulation pipeline, and the first heat exchanger is connected to the cold plate pipeline of the converter through a second circulation pipeline;

[0009] The first water pump is connected in series between the cold plate of the battery and the first heat exchanger, and the output end of the first water pump is also connected to one end of the electric valve;

[0010] The first input end and the output end of the three-way regulating valve are connected in series between the cold plate of the converter and the first heat exchanger, and the second input end of the three-way regulating valve is also connected to the other end of the electric valve;

[0011] The three-way regulating valve is used to adjust the flow ratio of the refrigerant liquid at its inlet to adjust the refrigerant temperature of the converter cold plate;

[0012] When the ambient temperature is greater than a first temperature threshold, the first water pump operates, and the refrigeration device provides different refrigerant liquid temperatures to the battery and the converter through the first circulation pipeline and the second circulation pipeline, respectively, to perform graded refrigeration and heat exchange.

[0013] Preferably, it also includes: an air-cooled radiator;

[0014] One end of the air-cooled radiator is connected to the output end of the first water pump, and the other end of the air-cooled radiator is respectively connected to the first input end of the three-way regulating valve and the cold plate of the battery;

[0015] When the ambient temperature is lower than a second temperature threshold, the refrigeration device is not started, and the first water pump is operated to perform graded cooling and heat exchange on the battery and the converter through the air-cooled radiator, wherein the second temperature threshold is lower than the first temperature threshold.

[0016] Preferably, the refrigeration device further comprises: a compressor, an expansion valve, a second heat exchanger and a liquid storage device;

[0017] The first heat exchanger, the compressor, the second heat exchanger, the liquid storage device and the expansion valve are sequentially arranged on the refrigerant circulation pipeline. The first heat exchanger serves as an evaporator and the second heat exchanger serves as a condenser. When the compressor is running, the refrigerant absorbs heat and cools through the first heat exchanger, and liquefies and releases heat through the second heat exchanger.

[0018] Preferably, the refrigerant liquid side of the second heat exchanger is connected to the air-cooled radiator pipeline through a third circulation pipeline, so that the second heat exchanger exchanges heat with the outside through the air-cooled radiator.

[0019] Preferably, it also includes: a second water pump;

[0020] The second water pump is arranged on the third circulation pipeline, and the second water pump is connected in series between the air-cooled radiator and the second heat exchanger. When the second water pump is running, the refrigerant in the third circulation pipeline is driven to circulate, so that the air-cooled radiator takes away the heat discharged by the second heat exchanger.

[0021] Preferably, it also includes: a pipeline heater;

[0022] The pipeline heater is arranged on the first circulation pipeline and is connected in series between the refrigerant output end of the first heat exchanger and the input end of the cold plate of the battery;

[0023] When the battery cell temperature is lower than a third temperature threshold, the pipe heater is used to heat the refrigerant in the first circulation pipeline to raise the temperature so that the refrigerant temperature of the cold plate of the battery is within a set range, wherein the third temperature threshold is lower than 14°C.

[0024] Preferably, the first heat exchanger and the second heat exchanger are both plate heat exchangers.

[0025] Preferably, it further comprises: a first solenoid valve, a second solenoid valve, a third solenoid valve and a fourth solenoid valve;

[0026] The first solenoid valve is connected in series between the output end of the first water pump and the refrigerant input end of the first heat exchanger;

[0027] The second solenoid valve is connected in series between the output end of the first water pump and the air-cooled radiator;

[0028] The third solenoid valve is connected in series between the refrigerant output end of the second heat exchanger and the air-cooled radiator;

[0029] The fourth solenoid valve is connected in series between the refrigerant liquid output end of the first heat exchanger and the refrigerant liquid output end of the second heat exchanger;

[0030] When the ambient temperature is greater than the first temperature threshold and the refrigeration device starts refrigeration, the second solenoid valve and the fourth solenoid valve are both closed, so that the first water pump drives the refrigerant in the first circulation pipeline and the second circulation pipeline to circulate, and the second water pump drives the refrigerant in the third circulation pipeline to circulate;

[0031] When the ambient temperature is lower than the second temperature threshold and the refrigeration device is not started, the first solenoid valve and the third solenoid valve are both turned off, and the second solenoid valve and the fourth solenoid valve are turned on, so that the air-cooled radiator cools and exchanges heat for the battery and the converter.

[0032] Preferably, it further comprises: a first electric three-way valve, a second electric three-way valve, a third electric three-way valve and a fourth electric three-way valve;

[0033] The first end of the first electric three-way valve is connected to the output end of the first water pump, the second end of the first electric three-way valve is connected to the refrigerant input end of the first heat exchanger, and the third end of the first electric three-way valve is connected to the first port of the second electric three-way valve;

[0034] The second port of the second electric three-way valve is connected to the refrigerant output end of the second heat exchanger, and the third port of the second electric three-way valve is connected to one end of the air-cooled radiator;

[0035] The first port of the third electric three-way valve is connected to one end of the pipeline heater, the second port of the third electric three-way valve is respectively connected to the refrigerant output end of the first heat exchanger and the first input end of the three-way regulating valve, and the third port of the third electric three-way valve is connected to the first port of the fourth electric three-way valve;

[0036] The second port of the fourth electric three-way valve is connected to the input end of the second water pump, and the third port of the fourth electric three-way valve is connected to the other end of the air-cooled radiator;

[0037] When the ambient temperature is greater than the first temperature threshold and the refrigeration device starts refrigeration, the pipeline flow between the first electric three-way valve and the second electric three-way valve is shut off, and the pipeline flow between the third electric three-way valve and the fourth electric three-way valve is shut off, so that the first heat exchanger cools and exchanges heat with the battery and the converter through the first circulation pipeline and the second circulation pipeline, and the second heat exchanger exchanges heat with the air-cooled radiator through the third circulation pipeline;

[0038] When the ambient temperature is lower than the second temperature threshold and the refrigeration device is not started, the pipeline flow between the first electric three-way valve and the third electric three-way valve is shut off, and the pipeline flow between the second electric three-way valve and the fourth electric three-way valve is shut off, so that the air-cooled radiator performs heat exchange and cooling on the battery and the inverter.

[0039] Preferably, it also includes: an expansion tank and a liquid replenishment tank;

[0040] The expansion tank and the liquid replenishing water tank are both arranged on the pipeline corresponding to the input end side of the first water pump to replenish and exhaust the refrigerant in the first circulation pipeline.

[0041] The present invention provides a multi-circuit liquid cooling system for a liquid cooling unit, in which a battery and a converter are arranged in parallel at both ends of a first heat exchanger of a refrigeration device, and the first heat exchanger of the refrigeration device exchanges heat with the battery and the converter through a first circulation pipeline and a second circulation pipeline respectively, and distributes the flow through an electric valve and a three-way regulating valve to provide different refrigerant liquid temperatures. When the ambient temperature is low, the refrigeration unit is turned off, and the air-cooled radiator cools the battery and the converter through a fourth circulation pipeline and a fifth circulation pipeline using a natural cold source, which greatly improves the energy efficiency of the system. When the battery is not running and the battery core temperature is too low, the pipeline heater is turned on to heat the battery, and the battery and the converter are heated through the first circulation pipeline and the second circulation pipeline. The problem that the existing liquid cooling unit has no graded cooling of the battery and the converter, has large energy consumption, and is not energy-saving is solved, and the comprehensive energy efficiency of the liquid cooling unit throughout the year can be improved, and energy consumption can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the specific embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below.

[0043] Figure 1 It is a schematic diagram of a multi-circuit liquid cooling system for a liquid cooling unit provided by the present invention.

[0044] Figure 2 It is a schematic diagram of another multi-circuit liquid cooling system for a liquid cooling unit provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0045] In order to enable persons skilled in the art to better understand the solutions of the embodiments of the present invention, the embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings and implementation modes.

[0046] In view of the problem that the current liquid cooling unit has high energy consumption and is not energy-saving in cooling and heating batteries and converters, the present invention provides a multi-circuit liquid cooling system for the liquid cooling unit, which solves the problem that the existing liquid cooling unit has no classification in cooling batteries and converters, has high energy consumption and is not energy-saving, and can improve the comprehensive energy efficiency of the liquid cooling unit throughout the year and reduce energy consumption.

[0047] like Figure 1 and Figure 2As shown, a multi-circuit liquid cooling system for a liquid cooling unit includes: a refrigeration device, a first water pump P1, an electric valve V5 and a three-way regulating valve V6. The battery and the converter PCS are arranged in parallel at both ends of the first heat exchanger in the refrigeration device; the first heat exchanger of the refrigeration device is connected to the cold plate pipeline of the battery through the first circulation pipeline S1, and the first heat exchanger is connected to the cold plate pipeline of the converter through the second circulation pipeline S2; the first water pump P1 is connected in series between the cold plate of the battery and the first heat exchanger 1, and the output end of the first water pump P1 is also connected to one end of the electric valve V5; the first input end and the output end of the three-way regulating valve V6 are connected in series between the cold plate of the converter and the first heat exchanger 1, and the second input end of the three-way regulating valve V6 is also connected to the other end of the electric valve V5; the three-way regulating valve V6 is used to adjust the inlet refrigerant flow ratio to adjust the refrigerant temperature of the converter cold plate. When the ambient temperature is greater than the first temperature threshold, the first water pump P1 is operated, and the refrigeration device provides different refrigerant liquid temperatures to the battery and the converter through the first circulation pipe S1 and the second circulation pipe S2, respectively, to perform graded refrigeration and heat exchange.

[0048] Specifically, the refrigeration device can be divided into a fluorine system and a refrigerant system according to the circulating medium. A first heat exchanger is provided in the refrigeration device. The refrigerant of the fluorine system exchanges heat with the refrigerant system through the first heat exchanger. The first heat exchanger is provided with a refrigerant side and a refrigerant side. The refrigerant side of the first heat exchanger is connected to the cold plate pipeline of the battery through the first circulation pipeline, and is connected to the cold plate pipeline of the converter through the second circulation pipeline. The refrigerant side of the first heat exchanger is arranged on the refrigerant circulation pipeline of the refrigeration device. The refrigerant on the refrigerant side exchanges heat with the refrigerant on the refrigerant side, so that the refrigerant passing through the refrigerant side is cooled. The refrigerant in the first circulation pipeline returns to the first water pump P1 through the first water pump P1, the refrigerant side of the first heat exchanger 1, and the cold plate of the battery, so that the first heat exchanger 1 forms a refrigeration circulation loop for the cold plate of the battery. The refrigerant in the second circulation pipeline is divided into two paths after passing through the first water pump P1. One path enters the second input end of the three-way regulating valve V6 through the electric valve V5, and the other path enters the first input end of the three-way regulating valve V6 after cooling the refrigerant side of the first heat exchanger. The three-way regulating valve V6 adjusts the opening of the first input end and the second input end to adjust the ratio of the refrigerant flow rate at its inlet, so that the refrigerant after heat exchange with the battery is mixed with the refrigerant side of the first heat exchanger after cooling through the electric valve V5, and then enters the PCS cold plate from the output end of the three-way regulating valve V6, and finally returns to the first water pump P1 after mixing with the coolant from the battery cold plate. The electric valve V5 can also adjust the flow rate of the refrigerant flowing through, and together with the three-way regulating valve V6, realize the temperature adjustment of the refrigerant, so that the temperature of the refrigerant for the battery is 15-22℃, and the temperature of the refrigerant for the PCS is 40-50℃, realizing graded refrigeration.

[0049] In practical applications, when the ambient temperature is high, generally referring to the ambient temperature being greater than 10°C, the refrigeration device is operated for cooling, and the battery cells and PCS are cooled and heat exchanged through the first circulation pipeline and the second circulation pipeline. This method distributes the flow through the electric valve and the three-way regulating valve to provide different refrigerant liquid temperatures, and provides different cooling medium temperatures for battery cooling and converter cooling. This can solve the problem that the existing liquid cooling unit has no graded cooling for batteries and converters, resulting in high energy consumption and no energy saving. It can improve the comprehensive energy efficiency of the liquid cooling unit throughout the year and reduce energy consumption.

[0050] Furthermore, the system also includes: an air-cooled radiator; one end of the air-cooled radiator is connected to the output end of the first water pump, and the other end of the air-cooled radiator is respectively connected to the first input end of the three-way regulating valve and the cold plate of the battery; when the ambient temperature is lower than a second temperature threshold, the refrigeration device is not started, and the first water pump is operated to perform graded cooling and heat exchange on the battery and the inverter through the air-cooled radiator, wherein the second temperature threshold is lower than the first temperature threshold.

[0051] In practical applications, an exhaust fan can be installed on the air-cooled radiator to improve the heat dissipation efficiency. When the ambient temperature is low, generally less than 10°C, the fluorine system of the refrigeration device does not start. In order to cool the battery cells and PCS, natural cooling can be directly used. The air-cooled radiator performs heat exchange and refrigeration on the battery cells and PCS refrigerant. At this time, the external ambient air temperature is relatively low, meeting the refrigeration requirements. The air-cooled radiator can be a cooling tower structure to reduce energy consumption.

[0052] Furthermore, the refrigeration device also includes: a compressor, an expansion valve Z1, a second heat exchanger 2 and a liquid reservoir; the first heat exchanger 1, the compressor, the second heat exchanger 2, the liquid reservoir and the expansion valve Z1 are sequentially arranged on a refrigerant circulation pipeline, the first heat exchanger 1 serves as an evaporator, and the second heat exchanger 2 serves as a condenser. When the compressor is running, the refrigerant absorbs heat and cools through the first heat exchanger 1, and liquefies and releases heat through the second heat exchanger 2.

[0053] Specifically, when the compressor of the refrigeration device is running, the refrigerant is heated and pressurized, and then the heat is released through the condenser and condensed into a high-pressure liquid. Then, the high-pressure liquid is depressurized by the expansion valve and enters the evaporator, where it absorbs heat and evaporates into low-temperature and low-pressure steam, which is sucked into the compressor again to start a new cycle. In this embodiment, the first heat exchanger can be directly used as the evaporator of the refrigeration device, and the refrigeration device cools the outside through the first heat exchanger. When the ambient temperature is high, the compressor is started to operate the fluorine system of the refrigeration device, and the refrigerant circulates through the compressor, the second heat exchanger 2, the liquid storage device, the expansion valve Z1, the first heat exchanger 1 and the compressor in turn. Among them, the first heat exchanger 1 is an evaporator, and the cold generated by the evaporator is transferred to the refrigerant side to exchange heat with the refrigerant flowing through.

[0054] Furthermore, the refrigerant liquid side of the second heat exchanger 2 is connected to the air-cooled radiator pipeline through the third circulation pipeline S3, so that the second heat exchanger 2 exchanges heat with the outside through the air-cooled radiator.

[0055] The system also includes: a second water pump P2; the second water pump P2 is arranged on the third circulation pipeline S3, and the second water pump P2 is connected in series between the air-cooled radiator and the second heat exchanger. When the second water pump P2 is running, the refrigerant in the third circulation pipeline S3 is driven to circulate, so that the air-cooled radiator takes away the heat discharged by the second heat exchanger.

[0056] In actual application, when the ambient temperature is high, the refrigeration device is started, the compressor is running, the first heat exchanger 1 exchanges heat with the outside through the first circulation pipeline S1 and the second circulation pipeline S2 for cooling, and the heat generated by the heat exchange of the second heat exchanger 2 is exchanged with the air-cooled radiator through the third circulation pipeline S3. The traditional heat exchange between the refrigerant and the air is converted into the refrigerant first exchanging heat with the refrigerant liquid, and finally the refrigerant liquid exchanges heat with the outside through the radiator, so that the heat exchange efficiency of the system is improved. The second heat exchanger can be arranged outside the liquid cooling unit, such as arranged in the battery cabinet, or the air-cooled radiator and the second heat exchanger can be arranged in an open position such as the top of the box to improve the heat exchange efficiency.

[0057] The system also includes: a pipe heater; the pipe heater is arranged on the first circulation pipeline S1 and is connected in series between the refrigerant output end of the first heat exchanger 1 and the input end of the cold plate of the battery; when the battery core temperature is lower than a third temperature threshold, the refrigerant in the first circulation pipeline S1 is heated by the pipe heater to make the refrigerant temperature of the cold plate of the battery within a set range, wherein the third temperature threshold is lower than 14°C.

[0058] In actual applications, when the battery is not in operation and the cell temperature is lower than the third temperature threshold, the battery cell performance will be reduced. The third temperature threshold is determined by the heating start temperature and can be in the range of -20~14℃. Therefore, it is necessary to heat the battery cell to raise its temperature to the set range. The pipe heater is set to heat the refrigerant in the first circulation pipeline, thereby raising the cold plate temperature of the main battery to achieve cell heating.

[0059] Furthermore, the first heat exchanger 1 and the second heat exchanger 2 are both plate heat exchangers. Specifically, the evaporator and condenser of the fluorine cycle in the refrigeration device are both plate heat exchangers, which can be arranged inside the box, with a more compact structure and convenient modularization. At the same time, the refrigerant side and the refrigerant side of the first heat exchanger and the second heat exchanger can be connected through corresponding pipelines to achieve heat exchange.

[0060] In one embodiment, in order to realize the switching of multi-circuit liquid cooling pipelines, as shown in FIG. Figure 1 As shown, the system further includes: a first solenoid valve K1, a second solenoid valve K2, a third solenoid valve K3 and a fourth solenoid valve K4. The first solenoid valve K1 is connected in series between the output end of the first water pump P1 and the refrigerant input end of the first heat exchanger 1, and the first solenoid valve K1 is used to control the conduction or disconnection of the pipeline between the output end of the first water pump and the first heat exchanger 1.

[0061] The second solenoid valve K2 is connected in series between the output end of the first water pump P1 and the air-cooled radiator. The second solenoid valve K2 is used to control the conduction or disconnection of the pipeline between the first water pump P1 and the air-cooled radiator.

[0062] The third solenoid valve K3 is connected in series between the refrigerant output end of the second heat exchanger 2 and the air-cooled radiator. The third solenoid valve K3 is used to control the conduction or disconnection of the pipeline between the refrigerant output end of the second heat exchanger and the air-cooled radiator.

[0063] The fourth solenoid valve K4 is connected in series between the refrigerant output end of the first heat exchanger 1 and the refrigerant output end of the second heat exchanger, and is used to control the conduction or disconnection of the pipeline between the refrigerant output end of the first heat exchanger and the refrigerant input end of the second heat exchanger.

[0064] When the ambient temperature is greater than the first temperature threshold and the refrigeration device starts refrigeration, the second solenoid valve K2 and the fourth solenoid valve K4 are both closed, so that the first water pump P1 drives the refrigerant in the first circulation pipeline S1 and the second circulation pipeline S2 to circulate, and drives the refrigerant in the third circulation pipeline S3 to circulate through the second water pump P2.

[0065] At this time, the first circulation pipeline S1 is connected to the first water pump P1, the first solenoid valve K1, the first heat exchanger 1, the pipe heater, the battery cold plate, and the water pump P1 in sequence; the second circulation pipeline S2 is connected to the first water pump P1, the electric valve V5, the three-way regulating valve V6, the converter cold plate, and the first water pump P1 in sequence. The coolant is divided into two routes through the first water pump P1. One route is to cool the battery cell, passing through the solenoid valve K1, the first heat exchanger 1, the pipe heater, and the cold plate for cooling the battery, and finally mixed with the refrigerated liquid from the PCS and returned to the first water pump P1. The other route is from the first water pump P1 through the electric valve V5, mixed with the low-temperature coolant from the three-way regulating valve V6, and then enters the PCS cold plate to cool the PCS, and then mixed with the coolant from the battery cell and returned to the first water pump P1, providing different water temperatures for battery cell cooling and PCS cooling. At the same time, since the second solenoid valve K2 and the fourth solenoid valve K4 are closed, the refrigerant in the third circulation loop is not connected to the first circulation loop. The third circulation pipeline S3 is connected to the air-cooled radiator, the second water pump P2, the second heat exchanger 2, the third solenoid valve K3, and the air-cooled radiator in sequence. At this time, the second water pump P2 is running, and the coolant is from the second water pump P2, passes through the second heat exchanger 2, the third solenoid valve K3 and the air-cooled radiator in sequence, and finally returns to the second water pump P2, thereby taking away the exhaust heat of the second heat exchanger 2 through the air-cooled radiator.

[0066] When the ambient temperature is lower than the second temperature threshold and the refrigeration device is not started, the first solenoid valve K1 and the third solenoid valve K3 are both closed, and the second solenoid valve K2 and the fourth solenoid valve K4 are turned on, so that the air-cooled radiator cools and exchanges heat for the battery and the converter.

[0067] At this time, the ambient temperature is low, the refrigeration device is shut down, the first solenoid valve K1 and the third solenoid valve K3 are turned off, so that the refrigerant of the first heat exchanger does not enter the first circulation pipeline and the second circulation pipeline, and the air-cooled radiator directly cools the battery cells and PCS naturally. The air-cooled radiator cools the battery cells through the fourth circulation pipeline and cools the converter through the fifth circulation pipeline, wherein the fourth circulation pipeline is connected to the first water pump P1, the second solenoid valve K2, the air-cooled radiator, the fourth solenoid valve K4, the pipeline heater, the battery cold plate, and the first water pump P1 in sequence; the fifth circulation pipeline is connected to the first water pump P1, the second solenoid valve K2, the air-cooled radiator, the fourth solenoid valve K4, the three-way regulating valve V6, the converter cold plate, and the first water pump P1 in sequence. Therefore, through the mutual cooperation of the first solenoid valve, the second solenoid valve, the third solenoid valve and the fourth solenoid valve, the mutual switching of multiple circuits is realized, so as to adjust the refrigerant temperature of the battery and the inverter, shut down the refrigeration device at low ambient temperature, use the natural cold source of the air-cooled radiator, and cool the battery and the inverter through the fourth circulation pipeline and the fifth circulation pipeline, which can greatly improve the energy efficiency of the system.

[0068] In another embodiment, in order to realize the switching of multi-circuit liquid cooling pipelines, as shown in FIG. Figure 2 As shown, the system further includes: a first electric three-way valve V1, a second electric three-way valve V2, a third electric three-way valve V3 and a fourth electric three-way valve V4. The first end of the first electric three-way valve V1 is connected to the output end of the first water pump P1, the second end of the first electric three-way valve V1 is connected to the refrigerant input end of the first heat exchanger 1, and the third end of the first electric three-way valve V1 is connected to the first port of the second electric three-way valve V2.

[0069] The second port of the second electric three-way valve V2 is connected to the refrigerant output end of the second heat exchanger 2, and the third port of the second electric three-way valve V2 is connected to one end of the air-cooled radiator.

[0070] The first port of the third electric three-way valve V3 is connected to one end of the pipe heater, the second port of the third electric three-way valve V3 is respectively connected to the refrigerant output end of the first heat exchanger 1 and the first input end of the three-way regulating valve V6, and the third port of the third electric three-way valve V3 is connected to the first port of the fourth electric three-way valve V4.

[0071] The second port of the fourth electric three-way valve V4 is connected to the input end of the second water pump P2, and the third port of the fourth electric three-way valve V4 is connected to the other end of the air-cooled radiator.

[0072] When the ambient temperature is greater than the first temperature threshold and the refrigeration device starts cooling, the pipeline flow between the first electric three-way valve V1 and the second electric three-way valve V2 is shut off, and the pipeline flow between the third electric three-way valve V3 and the fourth electric three-way valve V4 is shut off, so that the first heat exchanger 1 cools and exchanges heat with the battery and the inverter through the first circulation pipeline S1 and the second circulation pipeline S2, and the second heat exchanger 2 exchanges heat with the air-cooled radiator through the third circulation pipeline S3.

[0073] When the ambient temperature is lower than the second temperature threshold and the refrigeration device is not started, the pipeline flow between the first electric three-way valve V1 and the third electric three-way valve V3 is shut off, and the pipeline flow between the second electric three-way valve V2 and the fourth electric three-way valve V4 is shut off, so that the air-cooled radiator performs heat exchange and cooling on the battery and the inverter.

[0074] In practical applications, the first electric three-way valve, the second electric three-way valve, the third electric three-way valve and the fourth electric three-way valve can be adjusted by controlling the opening of the corresponding ports to achieve automatic control of the on and off of each port.

[0075] The system also includes: an expansion tank and a liquid replenishment water tank; the expansion tank and the liquid replenishment water tank are both arranged on the pipeline corresponding to the input end side of the first water pump to replenish and exhaust the refrigerant in the first circulation pipeline.

[0076] In practical applications, such as Figure 1 and Figure 2 As shown, a liquid replenishment tank and an expansion tank are required in the circulation pipeline of the liquid cooling unit to replenish and exhaust the refrigerant in the circulation pipeline. The replenishment tank replenishes the refrigerant to the circulation pipeline through the replenishment pipeline. The replenishment pipeline is provided with a replenishment pump P3 and a one-way valve. At the same time, an automatic exhaust valve is provided in the battery's refrigerant pipeline to discharge the gas in the circulation pipeline in real time to increase the cooling effect.

[0077] It can be seen that the present invention provides a multi-circuit liquid cooling system for a liquid cooling unit, in which the battery and the converter are arranged in parallel at both ends of the first heat exchanger of the refrigeration device, and the first heat exchanger of the refrigeration device exchanges heat with the battery and the converter through the first circulation pipeline and the second circulation pipeline respectively, and distributes the flow through the electric valve and the three-way regulating valve to provide different refrigerant liquid temperatures. When the ambient temperature is low, the refrigeration device is turned off, and the air-cooled radiator cools the battery and the converter through the fourth circulation pipeline and the fifth circulation pipeline using a natural cold source, which greatly improves the energy efficiency of the system. When the battery is not running and the battery core temperature is too low, the pipeline heater is turned on to heat the battery, and the battery and the converter are heated through the first circulation pipeline and the second circulation pipeline. The existing liquid cooling unit solves the problem that the cooling of the battery and the converter is not graded, the energy consumption is large, and the energy saving is not energy-saving, and can improve the comprehensive energy efficiency of the liquid cooling unit throughout the year and reduce energy consumption.

[0078] The above describes in detail the structure, features and effects of the present invention based on the embodiments shown in the drawings. The above is only a preferred embodiment of the present invention, but the present invention is not limited to the scope of implementation shown in the drawings. Any changes made in accordance with the concept of the present invention, or modifications to equivalent embodiments with equivalent changes, which still do not exceed the spirit covered by the description and drawings, should be within the protection scope of the present invention.

Claims

1. A multi-circuit liquid cooling system for a liquid cooling unit, characterized in that: include: Refrigeration device, first water pump, electric valve and three-way regulating valve; The battery and the converter are arranged in parallel at two ends of the first heat exchanger in the refrigeration device; The first heat exchanger is connected to the cold plate pipeline of the battery through a first circulation pipeline, and the first heat exchanger is connected to the cold plate pipeline of the converter through a second circulation pipeline; The first water pump is connected in series between the cold plate of the battery and the first heat exchanger, and the output end of the first water pump is also connected to one end of the electric valve; The first input end and the output end of the three-way regulating valve are connected in series between the cold plate of the converter and the first heat exchanger, and the second input end of the three-way regulating valve is also connected to the other end of the electric valve; The three-way regulating valve is used to adjust the flow ratio of the refrigerant liquid at its inlet to adjust the refrigerant temperature of the converter cold plate; When the ambient temperature is greater than a first temperature threshold, the first water pump operates, and the refrigeration device provides different refrigerant liquid temperatures to the battery and the converter through the first circulation pipeline and the second circulation pipeline, respectively, to perform graded refrigeration and heat exchange.

2. The multi-circuit liquid cooling system for a liquid cooling unit according to claim 1, characterized in that: Also includes: Air-cooled radiator; One end of the air-cooled radiator is connected to the output end of the first water pump, and the other end of the air-cooled radiator is respectively connected to the first input end of the three-way regulating valve and the cold plate of the battery; When the ambient temperature is lower than a second temperature threshold, the refrigeration device is not started, and the first water pump is operated to perform graded cooling and heat exchange on the battery and the converter through the air-cooled radiator, wherein the second temperature threshold is lower than the first temperature threshold.

3. The multi-circuit liquid cooling system for a liquid cooling unit according to claim 2, characterized in that: The refrigeration device further comprises: a compressor, an expansion valve, a second heat exchanger and a liquid storage device; The first heat exchanger, the compressor, the second heat exchanger, the liquid storage device and the expansion valve are sequentially arranged on the refrigerant circulation pipeline. The first heat exchanger serves as an evaporator and the second heat exchanger serves as a condenser. When the compressor is running, the refrigerant absorbs heat and cools through the first heat exchanger, and liquefies and releases heat through the second heat exchanger.

4. The multi-circuit liquid cooling system for a liquid cooling unit according to claim 3, characterized in that: The refrigerant liquid side of the second heat exchanger is connected to the air-cooled radiator pipeline through a third circulation pipeline, so that the second heat exchanger exchanges heat with the outside through the air-cooled radiator.

5. The multi-circuit liquid cooling system for a liquid cooling unit according to claim 4, characterized in that: Also includes: Second water pump; The second water pump is arranged on the third circulation pipeline, and the second water pump is connected in series between the air-cooled radiator and the second heat exchanger. When the second water pump is running, the refrigerant in the third circulation pipeline is driven to circulate, so that the air-cooled radiator takes away the heat discharged by the second heat exchanger.

6. The multi-circuit liquid cooling system for a liquid cooling unit according to claim 5, characterized in that: Also includes: Duct heaters; The pipeline heater is arranged on the first circulation pipeline and is connected in series between the refrigerant output end of the first heat exchanger and the input end of the cold plate of the battery; When the battery cell temperature is lower than a third temperature threshold, the pipe heater heats the refrigerant in the first circulation pipeline to raise the temperature so that the refrigerant temperature of the cold plate of the battery is within a set range, wherein the third temperature threshold is lower than 14°C.

7. The multi-circuit liquid cooling system for a liquid cooling unit according to claim 6, characterized in that: The first heat exchanger and the second heat exchanger are both plate heat exchangers.

8. The multi-circuit liquid cooling system for a liquid cooling unit according to claim 7, characterized in that: Also includes: a first solenoid valve, a second solenoid valve, a third solenoid valve and a fourth solenoid valve; The first solenoid valve is connected in series between the output end of the first water pump and the refrigerant input end of the first heat exchanger; The second solenoid valve is connected in series between the output end of the first water pump and the air-cooled radiator; The third solenoid valve is connected in series between the refrigerant output end of the second heat exchanger and the air-cooled radiator; The fourth solenoid valve is connected in series between the refrigerant liquid output end of the first heat exchanger and the refrigerant liquid output end of the second heat exchanger; When the ambient temperature is greater than the first temperature threshold and the refrigeration device starts refrigeration, the second solenoid valve and the fourth solenoid valve are both closed, so that the first water pump drives the refrigerant in the first circulation pipeline and the second circulation pipeline to circulate, and the second water pump drives the refrigerant in the third circulation pipeline to circulate; When the ambient temperature is lower than the second temperature threshold and the refrigeration device is not started, the first solenoid valve and the third solenoid valve are both turned off, and the second solenoid valve and the fourth solenoid valve are turned on, so that the air-cooled radiator cools and exchanges heat for the battery and the converter.

9. The multi-circuit liquid cooling system for a liquid cooling unit according to claim 7, characterized in that: Also includes: a first electric three-way valve, a second electric three-way valve, a third electric three-way valve and a fourth electric three-way valve; The first end of the first electric three-way valve is connected to the output end of the first water pump, the second end of the first electric three-way valve is connected to the refrigerant input end of the first heat exchanger, and the third end of the first electric three-way valve is connected to the first port of the second electric three-way valve; The second port of the second electric three-way valve is connected to the refrigerant output end of the second heat exchanger, and the third port of the second electric three-way valve is connected to one end of the air-cooled radiator; The first port of the third electric three-way valve is connected to one end of the pipeline heater, the second port of the third electric three-way valve is respectively connected to the refrigerant output end of the first heat exchanger and the first input end of the three-way regulating valve, and the third port of the third electric three-way valve is connected to the first port of the fourth electric three-way valve; The second port of the fourth electric three-way valve is connected to the input end of the second water pump, and the third port of the fourth electric three-way valve is connected to the other end of the air-cooled radiator; When the ambient temperature is greater than the first temperature threshold and the refrigeration device starts refrigeration, the pipeline flow between the first electric three-way valve and the second electric three-way valve is shut off, and the pipeline flow between the third electric three-way valve and the fourth electric three-way valve is shut off, so that the first heat exchanger cools and exchanges heat with the battery and the converter through the first circulation pipeline and the second circulation pipeline, and the second heat exchanger exchanges heat with the air-cooled radiator through the third circulation pipeline; When the ambient temperature is lower than the second temperature threshold and the refrigeration device is not started, the pipeline flow between the first electric three-way valve and the third electric three-way valve is shut off, and the pipeline flow between the second electric three-way valve and the fourth electric three-way valve is shut off, so that the air-cooled radiator performs heat exchange and cooling on the battery and the inverter.

10. The multi-circuit liquid cooling system for a liquid cooling unit according to claim 8 or 9, characterized in that: Also includes: Expansion tank and make-up water tank; The expansion tank and the liquid replenishing water tank are both arranged on the pipeline corresponding to the input end side of the first water pump to replenish and exhaust the refrigerant in the first circulation pipeline.

Images