Energy storage battery liquid cooling temperature control system combining natural cooling and compressor refrigeration

Abstract

The utility model discloses an energy storage battery liquid cooling temperature control system combining natural cooling and compressor refrigeration, and relates to the technical field of energy storage equipment temperature control. The system comprises a compression cooling loop, a natural cooling loop, an environment temperature sensor and a controller, the compression cooling loop adopts a compressor refrigeration technology, the natural cooling loop is connected with the compression cooling loop in parallel, and the compression cooling loop comprises a compressor, a condensation pipe, an expansion valve and a first heat exchange plate which are sequentially and circularly communicated. The natural cooling loop comprises a liquid storage tank, a circulating pump, a natural cooling coil and a second heat exchange plate which are sequentially and circularly communicated, the two heat exchange plates are integrated in the evaporator and used for exchanging heat with the energy storage battery, and a compression cooling mode and a natural cooling mode can be switched at different environment temperatures through the hardware structure relation of the two heat exchange plates; therefore, the system energy efficiency can be improved by avoiding long-term operation of the compressor, and the phenomena of poor oil return and insufficient lubrication are avoided by avoiding long-term low rotating speed of the compressor, so that the reliability is improved and the service life is prolonged.

Description

A liquid-cooled temperature control system for energy storage batteries that combines natural cooling and compressor refrigeration. Technical Field

[0001] This utility model belongs to the field of temperature control technology for energy storage equipment, specifically relating to a liquid cooling temperature control system for energy storage batteries that combines natural cooling and compressor refrigeration. Background Technology

[0002] Liquid cooling systems for energy storage are cooling systems that reduce the internal temperature of energy storage devices through liquid circulation. Compared to traditional air-cooled systems, liquid cooling systems offer higher heat dissipation efficiency and better temperature control, making them particularly suitable for energy storage scenarios with high energy density and rapid charge / discharge.

[0003] Currently, traditional energy storage liquid cooling systems generally face the problem of low energy efficiency, especially when operating at low ambient temperatures. Existing energy storage liquid cooling systems typically employ compressor refrigeration technology, but in low ambient temperatures such as winter or nighttime, the compressor operates at low speeds for extended periods, leading not only to increased energy consumption but also potentially affecting the reliability and lifespan of the unit due to poor oil return and insufficient lubrication. Furthermore, energy storage systems have heat dissipation characteristics during battery charging and discharging, but existing temperature control systems often fail to fully utilize this characteristic, resulting in overall low energy efficiency. Summary of the Invention

[0004] The purpose of this invention is to provide a liquid cooling temperature control system for energy storage batteries that combines natural cooling and compressor refrigeration, in order to solve the problems of low energy efficiency, poor unit reliability and short lifespan caused by existing liquid cooling systems that rely solely on compressor refrigeration cycles for heat dissipation.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] This utility model provides a liquid cooling temperature control system for energy storage batteries that combines natural cooling and compressor refrigeration. It includes a compression cooling circuit using compressor refrigeration technology, a natural cooling circuit connected in parallel with the compression cooling circuit, an ambient temperature sensor, and a controller. The compression cooling circuit includes a compressor, a condenser, an expansion valve, and a first heat exchange plate that are connected in sequence. The natural cooling circuit includes a liquid storage tank, a circulating pump, a natural cooling coil, and a second heat exchange plate that are connected in sequence. The first heat exchange plate and the second heat exchange plate are respectively integrated in an evaporator and used for heat exchange with the energy storage battery.

[0007] The output of the ambient temperature sensor is communicatively connected to the input of the controller, and the output of the controller is communicatively connected to the controlled end of the compressor and the controlled end of the circulating pump, so as to switch between compression cooling and natural cooling under different ambient temperatures.

[0008] Based on the above-mentioned utility model, a new liquid cooling temperature control scheme for energy storage batteries is provided, which can switch between two cooling modes by combining natural cooling and compressor refrigeration technology. This scheme includes a compression cooling circuit using compressor refrigeration technology, a natural cooling circuit connected in parallel with the compression cooling circuit, an ambient temperature sensor, and a controller. The compression cooling circuit includes a compressor, a condenser, an expansion valve, and a first heat exchange plate connected in sequence. The natural cooling circuit includes a liquid storage tank, a circulating pump, a natural cooling coil, and a second heat exchange plate connected in sequence. The two heat exchange plates are integrated into the evaporator and used for heat exchange with the energy storage battery. Through their hardware structure, the compression cooling mode and the natural cooling mode can be switched at different ambient temperatures. This improves system energy efficiency by avoiding long-term compressor operation and eliminates poor oil return and insufficient lubrication by avoiding long-term low compressor speeds, thereby improving the reliability and extending the lifespan of the unit, facilitating practical application and promotion.

[0009] In one possible design, a lubricating oil separator and a return capillary tube are also included on the compressor, wherein the lubricating oil separator is used to separate and collect the used lubricating oil of the compressor;

[0010] The lubricating oil output end of the lubricating oil separator is connected to one end of the return oil capillary tube, and the other end of the return oil capillary tube is connected to the internal cavity of the compressor, so as to return the collected lubricating oil to the compressor cavity.

[0011] In one possible design, the controlled end of the lubricating oil separator is communicatively connected to the output end of the controller so that when the compressor speed is lower than a preset speed threshold, it can be periodically started and maintained for a preset duration under the control of the controller.

[0012] In one possible design, when the preset speed threshold is 20% to 40% of the compressor's rated speed, the lubricating oil separator is activated every 20 to 40 minutes and maintained for 5 to 15 seconds under the control of the controller.

[0013] In one possible design, a cooling fan is also included for blowing air toward the condenser tubes and / or the natural cooling coils;

[0014] The controlled end of the cooling fan is communicatively connected to the output end of the controller.

[0015] In one possible design, the natural cooling circuit further includes an electric three-way valve and a one-way valve, wherein the common end of the electric three-way valve is connected to the output end of the circulation pump, the first switching end of the electric three-way valve is connected to one end of the natural cooling coil, the input end of the one-way valve is connected to the other end of the natural cooling coil, and the second switching end of the electric three-way valve and the output end of the one-way valve are respectively connected to the input end of the second heat exchange plate.

[0016] The controlled end of the electric three-way valve is communicatively connected to the output end of the controller so that when the ambient temperature is in the first preset temperature range, the common end and the first switching end are connected and the common end and the second switching end are disconnected under the control of the controller. When the ambient temperature is in the second preset temperature range, the common end and the second switching end are connected and the common end and the first switching end are disconnected under the control of the controller. The first preset temperature range and the second preset temperature range do not overlap, and the first preset temperature range is lower than the second preset temperature range.

[0017] In one possible design, the natural cooling circuit also includes an electric heater and a coolant temperature sensor, wherein the coolant temperature sensor is arranged at the coolant inlet of the reservoir;

[0018] The output of the coolant temperature sensor is communicatively connected to the input of the controller, and the controlled end of the electric heater is communicatively connected to the output of the controller, so that when the coolant temperature on the inlet side is lower than a third preset temperature threshold, the electric heater is activated under the control of the controller.

[0019] In one possible design, a battery temperature sensor and a coolant temperature sensor are also included, wherein the battery temperature sensor is disposed on the module surface of the energy storage battery, and the coolant temperature sensor is disposed in the natural cooling loop;

[0020] The output terminals of the battery temperature sensor and the coolant temperature sensor are respectively communicatively connected to the input terminal of the controller.

[0021] In one possible design, a pressure sensor and a flow meter are also included, wherein the pressure sensor is arranged in the compression cooling circuit and the flow meter is arranged in the natural cooling circuit;

[0022] The output terminals of the pressure sensor and the flow meter are respectively communicatively connected to the input terminal of the controller.

[0023] In one possible design, the energy storage battery includes a lithium battery or a flow battery.

[0024] In one possible design, the controller controls the compressor and the circulating pump according to the following operating mode:

[0025] Natural cooling mode: When the ambient temperature is less than or equal to a first preset temperature threshold, the compressor is turned off and the circulation pump is turned on;

[0026] Hybrid cooling mode: When the ambient temperature is greater than the first preset temperature threshold and less than or equal to the second preset temperature threshold, the compressor and the circulation pump are turned on intermittently, wherein the second preset temperature threshold is greater than the first preset temperature threshold;

[0027] Compression cooling mode: When the ambient temperature is greater than the second preset temperature threshold, the compressor is turned on and the circulation pump is turned off.

[0028] In one possible design, the energy storage battery liquid cooling temperature control system further includes a battery temperature sensor, wherein the battery temperature sensor is arranged on the module surface of the energy storage battery, and the output of the battery temperature sensor is communicatively connected to the input of the controller.

[0029] Turning on the circulation pump includes: adaptively adjusting the operating frequency of the circulation pump so that the operating frequency is positively correlated with the battery temperature.

[0030] In one possible design, the energy storage battery liquid cooling temperature control system further includes a battery temperature sensor and a coolant temperature sensor, wherein the battery temperature sensor is arranged on the module surface of the energy storage battery, the coolant temperature sensor is arranged in the natural cooling circuit, and the output terminals of the battery temperature sensor and the coolant temperature sensor are respectively communicatively connected to the input terminal of the controller.

[0031] The compressor and the circulating pump are intermittently turned on, including: dynamically adjusting the operating parameters of the compressor and / or the operating parameters of the circulating pump based on the ambient temperature, battery temperature and coolant temperature, combined with a PID algorithm, wherein the operating parameters of the compressor include the intermittent start-up cycle and / or speed of the compressor, and the operating parameters of the circulating pump include the operating frequency of the circulating pump.

[0032] The beneficial effects of the above scheme are:

[0033] (1) This invention provides a new liquid cooling temperature control scheme for energy storage batteries that can switch between natural cooling and compressor refrigeration technologies. It includes a compression cooling circuit using compressor refrigeration technology, a natural cooling circuit connected in parallel with the compression cooling circuit, an ambient temperature sensor and a controller. The compression cooling circuit includes a compressor, a condenser, an expansion valve and a first heat exchange plate connected in sequence. The natural cooling circuit includes a liquid storage tank, a circulating pump, a natural cooling coil and a second heat exchange plate connected in sequence. The two heat exchange plates are integrated in the evaporator and used to exchange heat with the energy storage battery. Through their hardware structure relationship, the compression cooling mode and the natural cooling mode can be switched at different ambient temperatures. This can improve the system energy efficiency by avoiding long-term operation of the compressor, and eliminate poor oil return and insufficient lubrication by avoiding long-term low speed of the compressor, thereby improving the reliability of the unit and extending its life.

[0034] (2) Improves energy efficiency: By using natural cooling at low ambient temperatures, unnecessary energy consumption of the compressor is avoided, thus improving overall energy efficiency;

[0035] (3) Enhanced reliability: This means reducing the compressor's operating time at low speeds, reducing the risk of failure due to poor oil return, and improving the reliability of the unit;

[0036] (4) It can improve the energy efficiency and reliability of energy storage systems under different ambient temperatures, and is particularly suitable for scenarios that require efficient thermal management, such as lithium battery energy storage systems and flow battery energy storage systems, which is convenient for practical application and promotion. Attached Figure Description

[0037] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 is a schematic diagram of the structure of the energy storage battery liquid cooling temperature control system that combines natural cooling and compressor refrigeration according to an embodiment of the present invention. Detailed Implementation

[0039] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the present utility model will be briefly introduced below in conjunction with the accompanying drawings and descriptions of the embodiments or the prior art. Obviously, the following description of the structure of the accompanying drawings is only some embodiments of this utility model. For those skilled in the art, other embodiments can be obtained based on these embodiments without creative effort. It should be noted that the description of these embodiments is used to help understand this utility model, but does not constitute a limitation on this utility model.

[0040] It should be understood that although the terms "first" and "second", etc., may be used herein to describe various objects, these objects should not be limited by these terms. These terms are only used to distinguish one object from another. For example, the first object may be referred to as the second object, and similarly, the second object may be referred to as the first object, without departing from the scope of the exemplary embodiments of this utility model.

[0041] It should be understood that the term "and / or" that may appear in this document is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can mean: A exists alone, B exists alone, or A and B exist simultaneously. Another example is A, B and / or C, which can mean that any one of A, B, and C or any combination thereof exists. The term " / and" that may appear in this document describes another relationship between related objects, indicating that two relationships can exist. For example, A / and B can mean: A exists alone or A and B exist simultaneously. In addition, the character " / " that may appear in this document generally indicates that the related objects before and after it are in an "or" relationship.

[0042] Example

[0043] As shown in Figure 1, the energy storage battery liquid cooling temperature control system provided in this embodiment, which combines natural cooling and compressor refrigeration, includes, but is not limited to, a compression cooling circuit using compressor refrigeration technology, a natural cooling circuit connected in parallel with the compression cooling circuit, an ambient temperature sensor 31, and a controller 4. The compression cooling circuit includes, but is not limited to, a compressor 11, a condenser 12, an expansion valve 13, and a first heat exchange plate 14 connected in sequence. The natural cooling circuit includes, but is not limited to, a liquid storage tank 21, a circulating pump 22, a natural cooling coil 23, and a second heat exchange plate 24 connected in sequence. The first heat exchange plate 14 and the second heat exchange plate 24 are respectively integrated in the evaporator 40 and used for heat exchange with the energy storage battery. The output of the ambient temperature sensor 31 is communicatively connected to the input of the controller 4, and the output of the controller 4 is communicatively connected to the controlled end of the compressor 11 and the controlled end of the circulating pump 22, so as to switch between compression cooling and natural cooling under different ambient temperatures.

[0044] As shown in Figure 1, in the specific structure of the liquid cooling temperature control system for the energy storage battery, the compression cooling circuit is a conventional structure in existing liquid cooling systems for energy storage. Therefore, the specific uses and hardware selection of the compressor 11, the condenser 12, the expansion valve 13, and the first heat exchange plate 14 can be derived conventionally based on existing solutions, and will not be elaborated here. The refrigerant in the compression cooling circuit can be liquid, gas, or a combination of both (when the refrigerant is liquid, another liquid storage tank can also be configured in the compression cooling circuit for temporary storage). The natural cooling loop is used to allow the coolant (e.g., water) in the loop to flow from the storage tank 21 to the natural cooling coil 23 when the circulation pump 22 is turned on (i.e., natural cooling is turned on). The coolant then obtains cooling energy from the low-temperature environment through the natural cooling coil 23 and carries it to the second heat exchange plate 24 for heat exchange and cooling with the energy storage battery. Finally, it flows back to the storage tank 21 for the next cycle. The storage tank 21 can be conventionally implemented using existing tank structures. The circulation pump 22 is preferably implemented using a variable frequency water pump. The natural cooling coil 23 and the second heat exchange plate 24 can both be conventionally implemented using existing corresponding products. The evaporator 40 provides the parallel connection point between the compression cooling loop and the natural cooling loop. The ambient temperature sensor 31 is used to be arranged on the environmental side to collect the ambient temperature in real time and transmit the collected results to the controller 4 in real time. It can be conventionally implemented using existing sensor products. The controller 4 is used to switch between compression cooling and natural cooling by routinely turning the compressor 1 and the circulating pump 22 on and off under different ambient temperatures. (For example, at low ambient temperatures, compression cooling is turned off and natural cooling is turned on to cool the energy storage battery; at high ambient temperatures, natural cooling is turned off and compression cooling is turned on to cool the energy storage battery.) This improves system energy efficiency by avoiding prolonged compressor operation and prevents poor oil return and insufficient lubrication by avoiding prolonged low compressor speeds, thereby enhancing unit reliability and extending lifespan. The hardware selection for the controller 4 can be, but is not limited to, conventional implementations using existing microcontroller chips or FPGAs (Field-Programmable Gate Arrays). Furthermore, the energy storage battery specifically includes, but is not limited to, lithium batteries or flow batteries.

[0045] Preferably, in order to combine natural cooling and compressor refrigeration to achieve intelligent and seamless switching between compression cooling and natural cooling, the controller 4 can control the compressor 11 and the circulating pump 22 in the following working modes (A) to (C), but is not limited to.

[0046] (A) Natural cooling mode: When the ambient temperature is less than or equal to a first preset temperature threshold, the compressor 11 is turned off (i.e., compression cooling is turned off), and the circulation pump 22 is turned on. The aforementioned first preset temperature threshold is, for example but not limited to, 15 degrees Celsius.

[0047] (B) Hybrid Cooling Mode: When the ambient temperature is greater than the first preset temperature threshold and less than or equal to the second preset temperature threshold, the compressor 11 is intermittently activated (i.e., compression cooling is intermittently activated), and the circulating pump 22 is activated, wherein the second preset temperature threshold is greater than the first preset temperature threshold. In this mode, natural cooling assists compression cooling to exchange heat and lower the temperature of the energy storage battery. Furthermore, the aforementioned second preset temperature threshold is, for example, but not limited to, 25 degrees Celsius.

[0048] (C) Compression Cooling Mode: When the ambient temperature is greater than the second preset temperature threshold, the compressor 11 is turned on and the circulation pump 22 is turned off (i.e., natural cooling is turned off). At this time, the compressor 11 will operate at full power and dissipate heat through the condenser pipe 12.

[0049] Preferably, the compressor 11 also includes, but is not limited to, a lubricating oil separator and a return capillary tube configured on the compressor 11. The lubricating oil separator separates and collects the used lubricating oil from the compressor 11. The lubricating oil output end of the lubricating oil separator is connected to one end of the return capillary tube, and the other end of the return capillary tube is connected to the internal cavity of the compressor 11, so as to return the collected lubricating oil to the compressor cavity. The aforementioned lubricating oil separator (not shown in Figure 1) and return capillary tube (not shown in Figure 1) can both be conventionally implemented using existing products; their installation positions can also be conventionally determined according to the specific structure of the compressor 11. Through the aforementioned combined configuration, poor oil return and insufficient lubrication can be further eliminated when the compressor is running at low speed, promoting improved unit reliability and extending its service life.

[0050] Preferably, the controlled end of the lubricating oil separator is communicatively connected to the output end of the controller 4, so that when the speed of the compressor 11 is lower than a preset speed threshold, it is periodically started and maintained for a preset duration under the control of the controller 4. Through the aforementioned periodic control of the lubricating oil separator, lubricating oil can be periodically collected and returned during low-speed operation of the compressor, further preventing poor oil return and insufficient lubrication. Specifically, when the preset speed threshold is 20% to 40% (for example, 30%) of the rated speed of the compressor 11, the lubricating oil separator is started every 20 to 40 minutes (for example, 30 minutes) and maintained for 5 to 15 seconds (for example, 10 seconds) under the control of the controller 4.

[0051] Preferably, the system also includes, but is not limited to, a cooling fan 6 for blowing air onto the condenser coil 12 and / or the natural cooling coil 23; the controlled end of the cooling fan 6 is communicatively connected to the output end of the controller 4. Through the aforementioned configuration of the cooling fan 6, the heat dissipation efficiency of the condenser coil 12 and / or the natural cooling coil 23 can be improved under the control of the controller 4, further enhancing the system's energy efficiency.

[0052] Preferably, the natural cooling circuit further includes, but is not limited to, an electric three-way valve 25 and a one-way valve 26, wherein the common end of the electric three-way valve 25 is connected to the output end of the circulating pump 22, the first switching end of the electric three-way valve 25 is connected to one end of the natural cooling coil 23, the input end of the one-way valve 26 is connected to the other end of the natural cooling coil 23, and the second switching end of the electric three-way valve 25 and the output end of the one-way valve 26 are respectively connected to the input end of the second heat exchange plate 24; the controlled end of the electric three-way valve 25 is communicatively connected to the output end of the controller 4 so that when the ambient temperature is in the first preset temperature range, the common end and the first switching end are connected and the common end and the second switching end are disconnected under the control of the controller 4; and when the ambient temperature is in the second preset temperature range, the common end and the second switching end are connected and the common end and the first switching end are disconnected under the control of the controller 4. The first preset temperature range and the second preset temperature range do not overlap, and the first preset temperature range is lower than the second preset temperature range. The electrically operated three-way valve 25 is used to switch between a long-range natural cooling circuit (i.e., the circuit including the natural cooling coil 23) and a short-range cooling circuit (i.e., the circuit excluding the natural cooling coil 23), so as to prevent ambient heat from being carried into and transferred to the energy storage battery when the ambient temperature is too high, thus ensuring the temperature control of the energy storage battery. For example, the first preset temperature range is less than or equal to 23 degrees Celsius, and the second preset temperature range is higher than 23 degrees Celsius. Furthermore, the electrically operated three-way valve 25 and the one-way valve 26 can be implemented using existing related products.

[0053] Preferably, the natural cooling circuit also includes, but is not limited to, an electric heater 27 and a coolant temperature sensor. The coolant temperature sensor is located at the coolant inlet of the storage tank 21. The output of the coolant temperature sensor is communicatively connected to the input of the controller 4, and the controlled end of the electric heater 27 is communicatively connected to the output of the controller 4, so that when the coolant temperature at the inlet is lower than a third preset temperature threshold, the electric heater 27 is activated under the control of the controller 4. The coolant temperature sensor (not shown in Figure 1) is used to collect the coolant temperature at the inlet in real time and transmit the collection result to the controller 4 in real time. It can be conventionally implemented using existing sensor products. Through the aforementioned configuration design, when the coolant temperature in the natural cooling circuit is too low, the electric heater 27 can appropriately heat the coolant to ensure smooth circulation. For example, when the coolant in the natural cooling circuit is water, the third preset temperature threshold is specifically 4 degrees Celsius.

[0054] Preferably, the system also includes, but is not limited to, a battery temperature sensor 32 and a coolant temperature sensor. The battery temperature sensor 32 is disposed on the surface of the energy storage battery module, and the coolant temperature sensor is disposed in the natural cooling loop. The output terminals of the battery temperature sensor and the coolant temperature sensor are respectively communicatively connected to the input terminal of the controller 4. The battery temperature sensor 32 is used to collect the battery temperature in real time and transmit the collection result to the controller 4 in real time; it can be implemented using existing sensor products. The coolant temperature sensor is used to collect the coolant temperature in the natural cooling loop in real time (e.g., the inlet-side coolant temperature and / or the outlet-side coolant temperature) and transmit the collection result to the controller 4 in real time; it can also be implemented using existing sensor products. There can be two coolant temperature sensors, one disposed at the coolant inlet of the storage tank 21 to collect the inlet-side coolant temperature, and the other disposed at the coolant outlet of the storage tank 21 to collect the outlet-side coolant temperature. Through the aforementioned configuration design of the two temperature sensors, richer feedback parameters can be provided for the intelligent operation of the controller 4, further facilitating system intelligence.

[0055] Specifically, when the energy storage battery liquid cooling temperature control system also includes the battery temperature sensor 32, the circulation pump 22 is activated, including but not limited to the following steps: adaptively adjusting the operating frequency of the circulation pump 22 so that the operating frequency is positively correlated with the battery temperature. This utilizes the heat dissipation characteristics during the charging and discharging process of the energy storage battery, allowing the power consumption of the circulation pump 22 to dynamically adapt to the battery temperature, further improving system energy efficiency.

[0056] Specifically, when the energy storage battery liquid cooling temperature control system also includes the battery temperature sensor 32 and the coolant temperature sensor, the compressor 11 is turned on intermittently, and the circulation pump 22 is turned on, including but not limited to the following steps: dynamically adjusting the operating parameters of the compressor 11 and / or the operating parameters of the circulation pump 22 according to the ambient temperature, battery temperature and coolant temperature, combined with a PID algorithm. The operating parameters of the compressor 11 include but are not limited to the intermittent start-up cycle and / or speed of the compressor 11, and the operating parameters of the circulation pump 22 include but are not limited to the operating frequency of the circulation pump 22. The PID algorithm described is a closed-loop control algorithm based on a combination of proportional, integral, and derivative components. It is used to eliminate system errors and achieve stable control. By adjusting the output in real time, it enables the controlled object to quickly and accurately reach the set value. It is widely used in industrial control, robotics, aerospace, and other fields. Therefore, it can be applied to this embodiment to dynamically adjust the intermittent start-up cycle of the compressor 11, the speed of the compressor 11, and / or the operating frequency of the circulating pump 22 based on multiple feedback parameters such as the ambient temperature, the battery temperature, and the coolant temperature (e.g., inlet-side coolant temperature, outlet-side coolant temperature, or their temperature difference). This adapts to specific mixed cooling requirements and further utilizes the heat dissipation characteristics during the charging and discharging process of the energy storage battery to improve system energy efficiency. Furthermore, the first preset temperature threshold and the second preset temperature threshold can be dynamically adjusted based on the ambient temperature, battery temperature, and coolant temperature to further enhance the flexibility and intelligence of switching between natural cooling and compression cooling.

[0057] Preferably, the system also includes, but is not limited to, pressure sensors and flow meters. The pressure sensor is arranged in the compression cooling circuit, and the flow meter is arranged in the natural cooling circuit. The output terminals of the pressure sensor and the flow meter are respectively communicatively connected to the input terminal of the controller 4. The aforementioned pressure sensor is used to collect the fluid pressure (which can be gas pressure or hydraulic pressure) of the refrigerant in the compression cooling circuit in real time and transmit the collected results to the controller 4 in real time. This can be conventionally implemented using existing sensor products. The aforementioned flow meter is used to collect the flow rate of the coolant in the natural cooling circuit in real time and transmit the collected results to the controller 4 in real time. This can also be conventionally implemented using existing sensor products. Through the configuration design of the aforementioned pressure sensor and flow meter, richer feedback parameters can be provided for the intelligent operation of the controller 4, further facilitating system intelligence.

[0058] In summary, the liquid-cooled temperature control system for energy storage batteries that combines natural cooling and compressor refrigeration, as provided in this embodiment, has the following technical advantages:

[0059] (1) This embodiment provides a new liquid cooling temperature control scheme for energy storage batteries that can switch between dual cooling modes by combining natural cooling and compressor refrigeration technology. It includes a compression cooling circuit using compressor refrigeration technology, a natural cooling circuit connected in parallel with the compression cooling circuit, an ambient temperature sensor and a controller. The compression cooling circuit includes a compressor, a condenser, an expansion valve and a first heat exchange plate connected in sequence. The natural cooling circuit includes a liquid storage tank, a circulating pump, a natural cooling coil and a second heat exchange plate connected in sequence. The two heat exchange plates are integrated in the evaporator and used to exchange heat with the energy storage battery. Through their hardware structure relationship, the compression cooling mode and the natural cooling mode can be switched at different ambient temperatures. This can improve the system energy efficiency by avoiding long-term operation of the compressor, and eliminate poor oil return and insufficient lubrication by avoiding long-term low speed of the compressor, thereby improving the reliability of the unit and extending its life.

[0060] (2) Improves energy efficiency: By using natural cooling at low ambient temperatures, unnecessary energy consumption of the compressor is avoided, thus improving overall energy efficiency;

[0061] (3) Enhanced reliability: This means reducing the compressor's operating time at low speeds, reducing the risk of failure due to poor oil return, and improving the reliability of the unit;

[0062] (4) It can improve the energy efficiency and reliability of energy storage systems under different ambient temperatures, and is particularly suitable for scenarios that require efficient thermal management, such as lithium battery energy storage systems and flow battery energy storage systems, which is convenient for practical application and promotion.

[0063] Finally, it should be noted that the above description is merely a preferred embodiment of this utility model and is not intended to limit the scope of protection of this utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.

Claims

1. A liquid-cooled temperature control system for energy storage batteries that combines natural cooling and compressor refrigeration, characterized in that, The system includes a compression cooling circuit using compressor refrigeration technology, a natural cooling circuit connected in parallel with the compression cooling circuit, an ambient temperature sensor (31), and a controller (4). The compression cooling circuit includes a compressor (11), a condenser (12), an expansion valve (13), and a first heat exchange plate (14) connected in sequence. The natural cooling circuit includes a liquid storage tank (21), a circulation pump (22), a natural cooling coil (23), and a second heat exchange plate (24) connected in sequence. The first heat exchange plate (14) and the second heat exchange plate (24) are integrated in an evaporator (40) and used for heat exchange with the energy storage battery. The output of the ambient temperature sensor (31) is communicatively connected to the input of the controller (4). The output of the controller (4) is communicatively connected to the controlled end of the compressor (11) and the controlled end of the circulation pump (22) to switch between compression cooling and natural cooling under different ambient temperatures.

2. The energy storage battery liquid cooling temperature control system as described in claim 1, characterized in that, It also includes a lubricating oil separator and a return capillary tube configured on the compressor (11), wherein the lubricating oil separator is used to separate and collect the used lubricating oil of the compressor (11); the lubricating oil output end of the lubricating oil separator is connected to one end of the return capillary tube, and the other end of the return capillary tube is connected to the internal cavity of the compressor (11) so as to return the collected lubricating oil to the compressor cavity.

3. The energy storage battery liquid cooling temperature control system as described in claim 2, characterized in that, The controlled end of the lubricating oil separator is communicatively connected to the output end of the controller (4) so ​​that when the speed of the compressor (11) is lower than the preset speed threshold, it can be periodically started and maintained for a preset duration under the control of the controller (4).

4. The energy storage battery liquid cooling temperature control system as described in claim 3, characterized in that, When the preset speed threshold is 20% to 40% of the rated speed of the compressor (11), the lubricating oil separator starts once every 20 to 40 minutes and maintains it for 5 to 15 seconds under the control of the controller (4).

5. The energy storage battery liquid cooling temperature control system as described in claim 1, characterized in that, It also includes a cooling fan (6) for blowing air toward the condenser (12) and / or the natural cooling coil (23); the controlled end of the cooling fan (6) is communicatively connected to the output end of the controller (4).

6. The energy storage battery liquid cooling temperature control system as described in claim 1, characterized in that, The natural cooling circuit also includes an electric three-way valve (25) and a one-way valve (26). The common end of the electric three-way valve (25) is connected to the output end of the circulating pump (22). The first switching end of the electric three-way valve (25) is connected to one end of the natural cooling coil (23). The input end of the one-way valve (26) is connected to the other end of the natural cooling coil (23). The second switching end of the electric three-way valve (25) and the output end of the one-way valve (26) are respectively connected to the input end of the second heat exchange plate (24). The controlled end of the electric three-way valve (25) is connected to... The common terminal is connected to the output terminal of the controller (4) so ​​that when the ambient temperature is in the first preset temperature range, the common terminal and the first switching terminal are turned on and the common terminal and the second switching terminal are turned off under the control of the controller (4), and when the ambient temperature is in the second preset temperature range, the common terminal and the second switching terminal are turned on and the common terminal and the first switching terminal are turned off under the control of the controller (4). The first preset temperature range and the second preset temperature range have no intersection, and the first preset temperature range is lower than the second preset temperature range.

7. The energy storage battery liquid cooling temperature control system as described in claim 1, characterized in that, The natural cooling circuit also includes an electric heater (27) and a coolant temperature sensor, wherein the coolant temperature sensor is arranged at the coolant inlet of the storage tank (21); the output end of the coolant temperature sensor is communicatively connected to the input end of the controller (4), and the controlled end of the electric heater (27) is communicatively connected to the output end of the controller (4), so that when the coolant temperature on the inlet side is lower than the third preset temperature threshold, the electric heater (27) is activated under the control of the controller (4).

8. The energy storage battery liquid cooling temperature control system as described in claim 1, characterized in that, It also includes a battery temperature sensor (32) and a coolant temperature sensor, wherein the battery temperature sensor (32) is arranged on the module surface of the energy storage battery, and the coolant temperature sensor is arranged in the natural cooling circuit; the output terminal of the battery temperature sensor (32) and the output terminal of the coolant temperature sensor are respectively communicatively connected to the input terminal of the controller (4).

9. The energy storage battery liquid cooling temperature control system as described in claim 1, characterized in that, It also includes a pressure sensor and a flow meter, wherein the pressure sensor is arranged in the compression cooling circuit and the flow meter is arranged in the natural cooling circuit; the output end of the pressure sensor and the output end of the flow meter are respectively communicatively connected to the input end of the controller (4).

10. The energy storage battery liquid cooling temperature control system as described in claim 1, characterized in that, The energy storage battery includes a lithium battery or a flow battery.

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