Thermal management system and energy storage system

Abstract

The utility model relates to a thermal management system and an energy storage system, the energy storage system comprises a battery pack and an energy storage converter, the thermal management system comprises a first water cooling loop, a second water cooling loop and a refrigerant loop, and a water-water heat exchanger is arranged between the first water cooling loop and the second water cooling loop; a plate heat exchanger is arranged between the first water cooling loop and the refrigerant loop; the first water cooling loop comprises a first water cooling device, and the first water cooling device is arranged on the battery pack; the second water cooling loop comprises a second water cooling device and a three-way proportional valve, the second water cooling device is arranged on the energy storage converter, the first end of the three-way proportional valve is connected with the first end of the water-water heat exchanger, the second end of the three-way proportional valve is connected with the first end of the second water cooling device, and the third end of the three-way proportional valve is connected with the second end of the water-water heat exchanger; the second end of the second water cooling device is connected with the second end of the water-water heat exchanger. According to the invention, the temperature control precision of the energy storage converter can be improved, and the temperature fluctuation of the energy storage converter is within 1 DEG C.

Description

Technical Field

[0001] The present disclosure relates to the field of thermal management technology, and in particular to a thermal management system and an energy storage system. Background Art

[0002] With the update of battery technology and the development of the energy storage industry, the energy density of energy storage systems is higher and the demand for temperature control is also greater. In order to ensure the safety performance of energy storage systems, energy storage thermal management systems are a feasible solution.

[0003] In the energy storage system, the parts that need to be temperature controlled are the battery and the energy storage inverter, and the temperature ranges of the battery and the energy storage inverter are not completely consistent. In the related technology, the energy storage thermal management system adopts a combination of battery liquid cooling and energy storage inverter air cooling. However, the heat dissipation efficiency of the energy storage inverter through air cooling is low, and the temperature controllability is poor, which affects the safety and stability of the energy storage system. Summary of the invention

[0004] In order to solve at least one of the above-mentioned technical problems, the present disclosure proposes a thermal management system and an energy storage system.

[0005] According to some embodiments of the present disclosure, a thermal management system is provided, which is applied to an energy storage system, wherein the energy storage system includes a battery pack and an energy storage inverter, and the thermal management system includes a first water cooling circuit, a second water cooling circuit and a refrigerant circuit, a water-to-water heat exchanger is provided between the first water cooling circuit and the second water cooling circuit, and a plate heat exchanger is provided between the first water cooling circuit and the refrigerant circuit; the first water cooling circuit includes a first water cooling device, which is provided on the battery pack, and a first water pump is provided in the first water cooling circuit; the second water cooling circuit includes a second water cooling device and a three-way proportional valve, which is provided on the energy storage inverter, a first end of the three-way proportional valve is connected to a first end of the water-to-water heat exchanger, a second end of the three-way proportional valve is connected to a first end of the second water cooling device, a third end of the three-way proportional valve is connected to a second end of the water-to-water heat exchanger, a second end of the second water cooling device is connected to a second end of the water-to-water heat exchanger, and a second water pump is provided in the second water cooling circuit.

[0006] Based on the above scheme, the battery pack and the energy storage inverter are both temperature controlled by liquid cooling. The refrigerant circuit directly exchanges heat with the first water cooling circuit to achieve temperature control of the battery pack. The refrigerant circuit indirectly exchanges heat with the second water cooling circuit through the first water cooling circuit to achieve temperature control of the energy storage inverter. The second water cooling circuit can adjust the flow rate of low-temperature coolant flowing into the second water cooling device by setting a three-way proportional valve, thereby improving the temperature control accuracy of the energy storage inverter.

[0007] In some possible embodiments, the refrigerant circuit includes a compressor, a condenser and an electronic expansion valve, and refrigerant is stored in the refrigerant circuit. The first outlet of the plate heat exchanger is connected to the inlet of the compressor, and the refrigerant flows along the compressor, the condenser and the electronic expansion valve in sequence to the first inlet of the plate heat exchanger.

[0008] Based on the above scheme, the refrigerant circuit can reduce the temperature fluctuation level of the refrigerant circuit by setting an electronic expansion valve, so that the refrigeration effect of the refrigerant circuit is stable, thereby helping to improve the temperature control accuracy of the thermal management system.

[0009] In some possible embodiments, in the first water cooling circuit, the second outlet of the plate heat exchanger is connected to the inlet of the first water pump, the outlet of the first water pump is connected to the first inlet of the water-to-water heat exchanger, the first outlet of the water-to-water heat exchanger is connected to the inlet of the first water cooling device, and the outlet of the first water cooling device is connected to the second inlet of the plate heat exchanger.

[0010] Based on the above scheme, the low-temperature coolant flowing out from the second outlet of the plate heat exchanger first flows into the water-to-water heat exchanger for heat exchange with the second water cooling circuit, and then flows to the first water cooling device to dissipate heat for the battery pack. Finally, the high-temperature coolant returns to the plate heat exchanger for heat exchange with the refrigerant circuit. Based on one refrigerant circuit, the temperature of the battery pack and the energy storage inverter can be controlled at the same time, and the heat dissipation control of the energy storage inverter is given priority to ensure the temperature control accuracy of the energy storage inverter.

[0011] In some possible embodiments, in the second water cooling circuit, the second outlet of the water-to-water heat exchanger is connected to the inlet of the second water pump, the outlet of the second water pump is connected to the first end of the three-way proportional valve, and the second inlet of the water-to-water heat exchanger is respectively connected to the third end of the three-way proportional valve and the second end of the second water cooling device.

[0012] Based on the above scheme, the low-temperature coolant flowing out from the second outlet of the water-to-water heat exchanger flows into the second water cooling device through the three-way proportional valve to dissipate heat for the energy storage inverter. The flow rate of the low-temperature coolant flowing into the second water cooling device can be changed by adjusting the opening and closing ratio of the three-way proportional valve. The excess low-temperature coolant flows back to the second inlet of the water-to-water heat exchanger from the bypass. While achieving precise control of the temperature of the energy storage inverter, the cold capacity can also be recovered to reduce the power consumption of the refrigerant circuit.

[0013] In some possible implementations, the thermal management system further includes a control module, and the control module is respectively connected to the compressor, the electronic expansion valve, the first water pump, the second water pump, and the three-way proportional valve via electrical signals.

[0014] Based on the above solution, the control module automatically generates control signals, which can achieve automatic control of the thermal management system and further improve the accuracy of temperature control.

[0015] In some possible implementations, the thermal management system further includes a temperature monitoring module, which is electrically connected to the control module and is used to monitor the temperature of the battery pack and the energy storage inverter and send the temperature to the control module.

[0016] Based on the above scheme, negative feedback control is implemented by monitoring the actual temperature of the battery pack and the energy storage inverter through the temperature monitoring module, which facilitates the control module to adjust the control signal in time, improve the stability of the thermal management system, and improve the temperature fluctuation of the battery pack and the energy storage inverter.

[0017] In some possible implementations, a heat dissipation device is further provided on the first water cooling circuit, and the heat dissipation device includes a heat dissipation water tank and a fan provided on the heat dissipation water tank.

[0018] Based on the above solution, the heat dissipation efficiency of the first water cooling circuit can be improved by additionally providing a heat dissipation device, thereby reducing the load pressure of the refrigerant circuit.

[0019] In some possible implementations, the thermal management system further includes a temperature reduction module, and the temperature reduction module is used to cool the second water cooling device and the energy storage converter.

[0020] Based on the above solution, by adding a cooling module, the condensation phenomenon caused by excessive temperature drop of the energy storage inverter can be improved, and the electrical components can be protected to avoid corrosion damage or short circuit failure.

[0021] In some possible implementations, the cooling module includes a humidity sensor and a cooling component, the control module is electrically connected to the humidity sensor and the cooling component respectively, and the control module receives the humidity signal monitored by the humidity sensor and sends a control signal to the cooling component.

[0022] Based on the above solution, the actual humidity value is monitored by a humidity sensor to achieve an automatic cooling effect and prevent condensation from affecting the temperature control efficiency.

[0023] According to some other embodiments of the present disclosure, there is also provided an energy storage system, including a battery pack and an energy storage inverter, and also including a thermal management system according to any one of the above embodiments, wherein a first water cooling device of the thermal management system is arranged on the battery pack, and a second water cooling device of the thermal management system is arranged on the energy storage inverter.

[0024] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure.

[0025] Further features and aspects of the present disclosure will become apparent from the following detailed description of exemplary embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions and advantages in the embodiments of this specification or the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of this specification. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0027] Figure 1 A system block diagram of a thermal management system according to an embodiment of the present disclosure is shown;

[0028] Figure 2 A system structure diagram of a thermal management system according to an embodiment of the present disclosure is shown;

[0029] Figure 3 shows a flow diagram of a refrigerant circuit according to an embodiment of the present disclosure;

[0030] Figure 4 shows a flow diagram of a first water cooling circuit according to an embodiment of the present disclosure;

[0031] Figure 5 A flow diagram of a second water cooling circuit according to an embodiment of the present disclosure is shown.

[0032] In the figure,

[0033] 100, refrigerant circuit; 101, compressor; 102, condenser; 103, electronic expansion valve; 200, first water cooling circuit; 201, first water pump; 202, first water cooling device; 300, second water cooling circuit; 301, second water pump; 302, three-way proportional valve; 303, second water cooling device; 400, plate heat exchanger; 500, water-to-water heat exchanger. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of this specification to clearly and completely describe the technical solutions in the embodiments of this specification. Obviously, the described embodiments are only part of the embodiments of this specification, not all of the embodiments. Based on the embodiments in this specification, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product, or server that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products, or devices.

[0036] Various exemplary embodiments, features and aspects of the present disclosure will be described in detail below with reference to the accompanying drawings. The same reference numerals in the accompanying drawings represent elements with the same or similar functions. Although various aspects of the embodiments are shown in the accompanying drawings, the drawings are not necessarily drawn to scale unless otherwise specified.

[0037] The word “exemplary” is used exclusively herein to mean “serving as an example, example, or illustration.” Any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments.

[0038] The term "and / or" herein is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the term "at least one" herein represents any combination of at least two of any one or more of a plurality of. For example, including at least one of A, B, and C can represent including any one or more elements selected from the set consisting of A, B, and C.

[0039] In addition, in order to better illustrate the present disclosure, numerous specific details are given in the following specific embodiments. It should be understood by those skilled in the art that the present disclosure can also be implemented without certain specific details. In some examples, methods, means, components and circuits well known to those skilled in the art are not described in detail in order to highlight the subject matter of the present disclosure.

[0040] To facilitate understanding of the present disclosure, some technical terms appearing in the present disclosure are explained or defined below:

[0041] EXV: Electronic Expansion Valve, electronic expansion valve, is a throttling control element with preset program, belonging to the electronic adjustment mode. It uses the electrical signal generated by the adjusted parameter to control the voltage or current applied to the expansion valve, thereby achieving the purpose of adjusting the liquid supply. Compared with traditional throttling elements (capillary tube, thermal expansion valve), the electronic expansion valve has a larger adjustment range, quick and sensitive action, precise adjustment, and stable and reliable.

[0042] PCS: Power Conversion System, energy storage converter, can control the charging and discharging process of the battery, perform AC / DC conversion, and directly supply power to AC loads when there is no power grid. PCS consists of DC / AC bidirectional converter, control unit, etc.

[0043] Energy storage system refers to a device or system that can convert electrical energy into other forms and convert it back to electrical energy when needed. Energy storage system generally includes batteries, battery management system (BMS) and power storage converter (PCS). Batteries and power storage converters need to work in a specific temperature range. Too high or too low temperature will cause the system to malfunction, so temperature control is required. With the update of battery technology and the development of energy storage industry, energy storage system has higher energy density and greater demand for temperature control, including the accuracy and stability of temperature control.

[0044] In order to ensure the safety performance of the energy storage system, the energy storage thermal management system is a feasible solution. In the related technology, the energy storage thermal management system adopts a combination of battery liquid cooling and energy storage inverter air cooling. However, the heat dissipation efficiency of the energy storage inverter through air cooling is low, and the temperature controllability is poor. There are also some solutions that use liquid cooling devices to dissipate heat from the energy storage inverter, but due to the good heat dissipation effect of liquid cooling, the temperature of the energy storage inverter is prone to be too low, resulting in condensation on the energy storage inverter, causing electrical components to become damp and posing a short circuit risk. Therefore, the energy storage thermal management system of the related technology cannot achieve high-precision temperature control, which in turn affects the safety and stability of the energy storage system.

[0045] In order to solve the above technical problems, an embodiment of the present disclosure provides a thermal management system, which is applied to an energy storage system. The thermal management system can achieve precise temperature control of an energy storage inverter in the energy storage system, so that the temperature control accuracy of the energy storage inverter is within 1°C.

[0046] In the disclosed embodiment, please refer to Figure 1The energy storage system includes a battery pack and an energy storage inverter. The thermal management system includes a first water cooling circuit 200, a second water cooling circuit 300 and a refrigerant circuit 100. The first water cooling circuit 200 is used to control the temperature of the battery pack, the second water cooling circuit 300 is used to control the temperature of the energy storage inverter, and the refrigerant circuit 100 is used to provide cooling for the first water cooling circuit 200 and the second water cooling circuit 300. Among them, a three-way proportional valve 302 is provided in the second water cooling circuit 300. The three-way proportional valve 302 includes a main circuit and a branch circuit. The main circuit flows through the energy storage inverter, and the branch circuit does not flow through the energy storage inverter. By adjusting the opening and closing ratio of the three-way proportional valve 302, the flow in the main circuit and the branch circuit can be controlled, thereby adjusting the main circuit flow through the energy storage inverter, so that the cooling capacity of the main circuit matches the heating value of the energy storage inverter. Specifically, when the heat generation of the energy storage inverter increases, the flow rate of the main circuit is increased and the flow rate of the branch circuit is reduced, thereby increasing the cooling capacity of the main circuit. When the heat generation of the energy storage inverter decreases, the flow rate of the main circuit is reduced and the flow rate of the branch circuit is increased, thereby reducing the cooling capacity of the main circuit. Based on the above operation, the temperature control accuracy of the energy storage inverter can be improved, and the temperature fluctuation of the energy storage inverter can be controlled within 1°C.

[0047] In the disclosed embodiment, the number of refrigerant circuits 100 is not limited, and the refrigerant circuit 100 may be a single compressor 101 refrigeration circuit, or a combination of multiple compressor 101 refrigeration circuits. In addition, the present embodiment also does not limit the form of heat exchange between the refrigerant circuit 100 and the first water cooling circuit 200 and the second water cooling circuit 300, that is, the refrigerant circuit 100 may directly exchange heat with the first water cooling circuit 200 and the second water cooling circuit 300, respectively, and the refrigerant circuit 100 may also exchange heat with the first water cooling circuit 200 and / or the second water cooling circuit 300 through an intermediate medium (such as other water cooling circuits, other heat exchangers, etc.).

[0048] It is worth noting that in the energy storage system, the battery pack and the energy storage inverter have different heat generation, and their operating temperature ranges are also different. Generally speaking, the operating temperature range of the battery pack is 20-35°C, and the operating temperature range of the energy storage inverter is 35-45°C. The operating temperature range of the energy storage inverter is higher than the operating temperature range of the battery pack. Therefore, the cooling capacity required by the two is different.

[0049] In order to achieve accurate temperature control of the energy storage converter and avoid excessive cooling capacity of the second water cooling circuit 300 causing condensation of the energy storage converter, please refer to Figure 2In the disclosed embodiment, the refrigerant circuit 100 performs direct heat exchange with the first water cooling circuit 200, while the first water cooling circuit 200 performs heat exchange with the second water cooling circuit 300. Specifically, a plate heat exchanger 400 is provided between the first water cooling circuit 200 and the refrigerant circuit 100, and the plate heat exchanger 400 includes two flow channels, and the two flow channels are respectively connected to the first water cooling circuit 200 and the refrigerant circuit 100; a water-to-water heat exchanger 500 is provided between the second water cooling circuit 300 and the first water cooling circuit 200, and the water-to-water heat exchanger 500 also includes two flow channels, and the two flow channels are respectively connected to the second water cooling circuit 300 and the first water cooling circuit 200. The cold energy generated by the refrigerant circuit 100 is directly transmitted to the first water cooling circuit 200 through the plate heat exchanger 400, and then indirectly transmitted to the second water cooling circuit 300 through the water-to-water heat exchanger 500. After two heat exchanges, the cold energy obtained by the second water cooling circuit 300 is less than the cold energy obtained by the first water cooling circuit 200, so that the temperature of the energy storage inverter is higher than the temperature of the battery pack, and the energy storage inverter and the battery pack can operate in their respective operating temperature ranges.

[0050] The first water cooling circuit 200 includes a first water cooling device 202, which is disposed on the battery pack and is used to absorb the heat generated by the battery pack. The first water cooling circuit 200 is provided with a first water pump 201, which is used to make the coolant in the first water cooling circuit 200 flow. The coolant absorbs the heat of the first water cooling device 202 and becomes a high-temperature coolant. The high-temperature coolant flows into the plate heat exchanger 400 to dissipate heat and becomes a low-temperature coolant again.

[0051] The second water cooling circuit 300 includes a second water cooling device 303 and a three-way proportional valve 302. The second water cooling device 303 is arranged on the energy storage converter and is used to absorb the heat generated by the energy storage converter. The first end of the three-way proportional valve 302 is connected to the first end of the water-to-water heat exchanger 500, the second end of the three-way proportional valve 302 is connected to the second end of the second water cooling device 303, the third end of the three-way proportional valve 302 is connected to the second end of the water-to-water heat exchanger 500, and the second end of the second water cooling device 303 is connected to the second end of the water-to-water heat exchanger 500, wherein the first end and the second end of the three-way proportional valve 302 are the main roads, and the third end of the three-way proportional valve 302 is the branch road. A second water pump 301 is provided in the second water cooling circuit 300. The second water pump 301 is used to make the coolant in the second water cooling circuit 300 flow. The coolant absorbs the heat of the second water cooling device 303 and becomes high-temperature coolant. The high-temperature coolant flows into the water-to-water heat exchanger 500 to dissipate heat and becomes low-temperature coolant again. The three-way proportional valve 302 can control the flow rate of the coolant flowing through the second water cooling device 303.

[0052] The above embodiments have briefly introduced the principles and functions of the thermal management system of the embodiments of the present disclosure. In order to more clearly illustrate the operation process of the thermal management system, the structures of each circuit are introduced in detail below.

[0053] In the embodiments of the present disclosure, please refer to Figure 3 The refrigerant circuit 100 includes a compressor 101, a condenser 102 and an electronic expansion valve 103. Refrigerant is stored in the refrigerant circuit 100. The first outlet of the plate heat exchanger 400 is connected to the inlet of the compressor 101. The refrigerant flows to the first inlet of the plate heat exchanger 400 along the compressor 101, the condenser 102 and the electronic expansion valve 103 in sequence. The first outlet and the first inlet are located at two end ports of the same flow channel in the plate heat exchanger 400. The plate heat exchanger 400 is a type of evaporator. The two flow channels of the plate heat exchanger 400 flow refrigerant and coolant respectively. The low-temperature and low-pressure refrigerant liquid absorbs the heat of the high-temperature coolant to reduce the temperature of the coolant, and the refrigerant liquid absorbs heat and evaporates to become a high-temperature and low-pressure refrigerant gas. The high-temperature and low-pressure refrigerant gas then enters the compressor 101 and is compressed by the compressor 101 into a high-temperature and high-pressure refrigerant gas. The high-temperature and high-pressure refrigerant gas enters the condenser 102 and exchanges heat with the ambient cooling medium and is condensed into a normal-temperature and high-pressure refrigerant liquid. The normal-temperature and high-pressure refrigerant liquid passes through the electronic expansion valve 103 and becomes a low-temperature and low-pressure refrigerant liquid again. The low-temperature and low-pressure refrigerant liquid finally flows into the plate heat exchanger 400 to complete the refrigeration cycle.

[0054] In this embodiment, the use of the electronic expansion valve 103 can improve the accuracy of cooling control. Compared with the capillary tube or other throttling components, the electronic expansion valve 103 can reduce the level of cooling fluctuation, thereby helping to improve the temperature control accuracy of the energy storage inverter and / or battery pack. It should be understood that the embodiments of the present disclosure do not limit the specific selection of the refrigerant circuit 100. The above-mentioned refrigerant circuit 100 structure is only a preferred exemplary structure. According to the actual temperature control needs of the energy storage system, the user can flexibly adjust the structure and component selection of the refrigerant circuit 100.

[0055] In the first water cooling circuit 200, please refer to Figure 4, the second outlet of the plate heat exchanger 400 is connected to the inlet of the first water pump 201, the outlet of the first water pump 201 is connected to the first inlet of the water-to-water heat exchanger 500, the first outlet of the water-to-water heat exchanger 500 is connected to the inlet of the first water cooling device 202, the outlet of the first water cooling device 202 is connected to the second inlet of the plate heat exchanger 400, and the first inlet and the first outlet of the water-to-water heat exchanger 500 are located at both ends of the first flow channel of the water-to-water heat exchanger 500. Based on the above structure, the low-temperature coolant flowing out of the plate heat exchanger 400 is sent to the water-to-water heat exchanger 500 by the first water pump 201, and the water-to-water heat exchanger 500 absorbs the heat of the second water cooling circuit 300, so that the low-temperature coolant is partially heated, and then the low-temperature coolant flows into the first water cooling device 202 to absorb the heat of the battery pack, and the high-temperature coolant after absorbing heat flows back to the plate heat exchanger 400 to complete the cycle.

[0056] In this embodiment, the purpose of arranging the water-to-water heat exchanger 500 upstream of the first cooling device is to ensure that the low-temperature coolant flowing out of the plate heat exchanger 400 needs to first enter the water-to-water heat exchanger 500 and then enter the first cooling device. If the low-temperature coolant enters the first cooling device first, since the cooling required by the battery pack is greater than the cooling required by the energy storage inverter, the coolant will heat up sharply after absorbing the heat of the battery pack, and then the heat exchange with the second water cooling circuit 300 cannot achieve a good heat absorption effect. Therefore, the low-temperature coolant needs to first enter the water-to-water heat exchanger 500 to absorb the heat of the energy storage inverter. The coolant flowing out of the water-to-water heat exchanger 500 has a lesser temperature rise and can continue to provide heat dissipation for the battery pack, which can not only reduce the load pressure of the refrigerant circuit 100, but also ensure the temperature control effect of the energy storage inverter and the battery pack.

[0057] In the second water cooling circuit 300, please refer to Figure 5, the second outlet of the water-to-water heat exchanger 500 is connected to the inlet of the second water pump 301, the outlet of the second water pump 301 is connected to the first end of the three-way proportional valve 302, the second inlet of the water-to-water heat exchanger 500 is respectively connected to the third end of the three-way proportional valve 302 and the second end of the second water cooling device 303, and the second outlet and the second inlet of the water-to-water heat exchanger 500 are located at both ends of the second flow channel of the water-to-water heat exchanger 500. Based on the above structure, the low-temperature coolant flowing out of the second flow channel of the water-to-water heat exchanger 500 first flows to the three-way proportional valve 302, and the three-way proportional valve 302 controls the flow of coolant flowing through the energy storage inverter by adjusting the opening and closing ratio of the second end and the third end, thereby achieving the purpose of precise temperature control, and the excess low-temperature coolant flows back to the water-to-water heat exchanger 500 from the branch at the third end, achieving the effect of cold recovery. It can be understood that when the energy storage inverter requires less cooling capacity, more low-temperature coolant flows through the branch circuit, the temperature of the coolant decreases after the branch circuit intersects with the main circuit, the cooling capacity demand of the water-to-water heat exchanger 500 decreases, and when the cooling capacity of the refrigerant circuit 100 remains unchanged, the cooling capacity reserved for the battery pack increases, achieving an energy-saving effect.

[0058] In some possible embodiments, in order to avoid insufficient cooling supply to the battery pack, a heat dissipation device is further provided on the first water cooling circuit 200. The heat dissipation device includes a heat dissipation water tank and a fan arranged on the heat dissipation water tank. The heat dissipation device assists the heat dissipation of the battery pack to ensure that the battery pack is maintained within the operating temperature range.

[0059] The above embodiments have explained how to realize temperature control of the energy storage system based on the thermal management system. In order to further improve the accuracy and real-time performance of temperature control, in some embodiments of the present disclosure, the thermal management system further includes a control module, which is respectively connected to the compressor 101, the electronic expansion valve 103, the first water pump 201, the second water pump 301 and the three-way proportional valve 302 by electrical signals. In this embodiment, the control module should have the functions of receiving, processing and sending signals. The control module can be a single-chip microcomputer, a microcomputer, an industrial computer, a host computer or other forms of devices. Based on the control module, the thermal management system can realize automatic temperature control.

[0060] In a specific embodiment, when the temperature of the energy storage inverter is precisely controlled, the refrigeration efficiency of the refrigerant circuit 100 is obtained by monitoring the compressor 101 and the electronic expansion valve 103, and then the rotation speeds of the first water pump 201 and the second water pump 301 are obtained, and the flow rates of the first water cooling circuit 200 and the second water cooling circuit 300 are obtained. Finally, by adjusting the opening and closing ratio of the three-way proportional valve 302, the energy storage inverter is maintained at the target temperature, thereby achieving precise temperature control of the energy storage inverter.

[0061] In another specific embodiment, the temperature of the energy storage inverter and the battery pack can be precisely controlled at the same time. After adjusting the opening and closing ratio of the three-way proportional valve 302, when the temperature of the battery pack is higher and more cooling is required, the speed of the compressor 101 is adjusted, and the three-way proportional valve is adjusted again until the energy storage inverter and the battery pack are maintained at their respective target temperatures.

[0062] In the above-mentioned implementation, the temperature control is adjusted multiple times by the control module alone, which is easy to cause over-control, and the heat generation of the battery pack and the energy storage converter is affected by the load and the ambient temperature and fluctuates. In order to further improve the accuracy and real-time performance of temperature control and reduce the degree of temperature fluctuation, the thermal management system also includes a temperature monitoring module, which is connected to the control module by electrical signals. The temperature monitoring module is used to monitor the temperature of the battery pack and the energy storage converter and send it to the control module. In addition, the temperature monitoring module can also be used to monitor the ambient temperature.

[0063] The thermal management system of the disclosed embodiment is designed around the temperature control of the energy storage inverter and the battery pack, and has high temperature control accuracy for the energy storage inverter, with the purpose of preventing condensation caused by the energy storage inverter being too low in temperature, thereby causing damage to the device. In order to further reduce the risk of device damage, in some embodiments of the disclosed embodiment, the thermal management system also includes a cooling module, which is used to cool the second water cooling device 303 and the energy storage inverter to prevent condensation. This embodiment does not limit the specific selection of the cooling module, and an adapted cooling module can be selected according to the structural model of the actual energy storage inverter.

[0064] In a specific embodiment, the cooling module includes a humidity sensor and a cooling component, the control module is electrically connected to the humidity sensor and the cooling component, the control module receives the humidity signal monitored by the humidity sensor and sends a control signal to the cooling component. Preferably, the humidity sensor can be a temperature and humidity sensor.

[0065] The disclosed embodiment also provides an energy storage system, including a battery pack, an energy storage inverter and a thermal management system described in any one of the above embodiments, wherein the first water cooling device 202 of the thermal management system is arranged on the battery pack, and the second water cooling device 303 of the thermal management system is arranged on the energy storage inverter. It should be understood that the disclosed embodiment does not limit the specific structure and selection of the first water cooling device 202 and the second water cooling device 303. The first water cooling device 202 can be a separate water cooling row, a water cooling heat exchange plate, a water cooling pipe, etc., and the first water cooling device 202 can also be a water cooling outer shell integrated with the battery pack; similarly, the second water cooling device 303 can be a separate water cooling row, a water cooling heat exchange plate, a water cooling pipe, etc., and the second water cooling device 303 can also be a water cooling outer shell integrated with the energy storage inverter.

[0066] The embodiments of the present disclosure have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or technical improvements in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A thermal management system is applied to an energy storage system, wherein the energy storage system includes a battery pack and an energy storage converter, and is characterized in that: The thermal management system comprises a first water cooling circuit (200), a second water cooling circuit (300) and a refrigerant circuit (100); a water-to-water heat exchanger (500) is provided between the first water cooling circuit (200) and the second water cooling circuit; and a plate heat exchanger (400) is provided between the first water cooling circuit (200) and the refrigerant circuit (100); The first water cooling circuit (200) comprises a first water cooling device (202), the first water cooling device (202) is arranged on the battery pack, and a first water pump (201) is arranged in the first water cooling circuit (200); The second water cooling circuit (300) comprises a second water cooling device (303) and a three-way proportional valve (302); the second water cooling device (303) is arranged on the energy storage inverter; the first end of the three-way proportional valve (302) is connected to the first end of the water-to-water heat exchanger (500); the second end of the three-way proportional valve (302) is connected to the first end of the second water cooling device (303); the third end of the three-way proportional valve (302) is connected to the second end of the water-to-water heat exchanger (500); the second end of the second water cooling device (303) is connected to the second end of the water-to-water heat exchanger (500); and a second water pump (301) is arranged in the second water cooling circuit (300).

2. The thermal management system according to claim 1, characterized in that: The refrigerant circuit (100) comprises a compressor (101), a condenser (102) and an electronic expansion valve (103); a refrigerant is stored in the refrigerant circuit (100); a first outlet of the plate heat exchanger (400) is connected to an inlet of the compressor (101); and the refrigerant flows in sequence along the compressor (101), the condenser (102) and the electronic expansion valve (103) to the first inlet of the plate heat exchanger (400).

3. The thermal management system according to claim 2, characterized in that: In the first water cooling circuit (200), the second outlet of the plate heat exchanger (400) is connected to the inlet of the first water pump (201), the outlet of the first water pump (201) is connected to the first inlet of the water-to-water heat exchanger (500), the first outlet of the water-to-water heat exchanger (500) is connected to the inlet of the first water cooling device (202), and the outlet of the first water cooling device (202) is connected to the second inlet of the plate heat exchanger (400).

4. The thermal management system according to claim 3, characterized in that: In the second water cooling circuit (300), the second outlet of the water-to-water heat exchanger (500) is connected to the inlet of the second water pump (301), the outlet of the second water pump (301) is connected to the first end of the three-way proportional valve (302), and the second inlet of the water-to-water heat exchanger (500) is respectively connected to the third end of the three-way proportional valve (302) and the second end of the second water cooling device (303).

5. The thermal management system according to any one of claims 2 to 4, characterized in that: The thermal management system further comprises a control module, which is respectively connected to the compressor (101), the electronic expansion valve (103), the first water pump (201), the second water pump (301) and the three-way proportional valve (302) via electrical signals.

6. The thermal management system according to claim 5, characterized in that: The thermal management system also includes a temperature monitoring module, which is electrically connected to the control module. The temperature monitoring module is used to monitor the temperature of the battery pack and the energy storage inverter and send the temperature to the control module.

7. The thermal management system according to claim 5, characterized in that: The first water cooling circuit (200) is also provided with a heat dissipation device, which comprises a heat dissipation water tank and a fan arranged on the heat dissipation water tank.

8. The thermal management system according to claim 5, characterized in that: The thermal management system further comprises a cooling module, which is used to cool the second water cooling device (303) and the energy storage converter to prevent condensation.

9. The thermal management system according to claim 8, characterized in that: The cooling module includes a humidity sensor and a cooling component. The control module is electrically connected to the humidity sensor and the cooling component respectively. The control module receives a humidity signal monitored by the humidity sensor and sends a control signal to the cooling component.

10. An energy storage system, comprising a battery pack and an energy storage converter, characterized in that: It also includes a thermal management system according to any one of claims 1 to 9, wherein a first water cooling device (202) of the thermal management system is arranged on the battery pack, and a second water cooling device (303) of the thermal management system is arranged on the energy storage inverter.

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