Energy storage heat management system

Abstract

The utility model provides an energy storage heat management system which comprises a compressor, a mode switching unit, a first heat exchanger, a second heat exchanger, a third heat exchanger, a fourth heat exchanger and a battery unit. The working modes of the energy storage heat management system comprise a refrigeration mode and a heating mode; in the heating mode, a refrigerant passes through the mode switching unit through the compressor, then sequentially flows through the second heat exchanger, the battery unit, the fourth heat exchanger, the third heat exchanger and the mode switching unit and then returns to the compressor to complete primary circulation, and secondary circulation heating is conducted through the compressor. In the refrigeration mode, a refrigerant passes through the mode switching unit through the compressor, then sequentially flows through the first heat exchanger, the fourth heat exchanger, the battery unit, the fourth heat exchanger and the mode switching unit and then returns to the compressor to complete primary circulation, and secondary circulation refrigeration is conducted through the compressor. An electric heating evaporator is adopted in the third heat exchanger, the temperature of a refrigerant is directly increased through electric heating, dependence on the environment temperature is not needed, the defrosting requirement is avoided, and stable heating can be achieved at the environment temperature of minus 40 DEG C; the four heat exchangers are cooperatively controlled, seamless switching of refrigerating / heating modes is achieved through combined configuration of the first to fourth heat exchangers, and it is ensured that the liquid supply temperature fluctuation is smaller than + / -1 DEG C.

Description

TECHNICAL FIELD

[0001] The utility model relates to battery heat management technical field especially a kind of energy storage heat management system. BACKGROUND

[0002] With the high-speed development of new energy technology, container type energy storage system is widely used in new energy grid connection, photovoltaic power station and intelligent microgrid and other fields due to its modular design, flexible deployment and high-efficiency integration advantages. Its standardized box structure not only significantly reduces the floor area, but also simplifies the transportation and installation process, becoming the mainstream choice of new energy industry. At the same time, the special heat management system for energy storage battery pack is rapidly evolving towards high stability and intelligence. If the heat management fails, the abnormal temperature fluctuation inside the battery pack will exacerbate the risk of thermal runaway, which may cause local short circuit, cell bulging and other faults, and even threaten the safe operation of surrounding equipment.

[0003] Currently, battery direct cooling technology as a new heat management scheme is becoming a research and development hotspot in the industry. Its core idea is to achieve efficient cooling by making refrigerant flow directly through the battery cold plate. However, this technology cancels the cooling liquid circuit in the traditional liquid cooling system, making it difficult to use the PTC heating scheme that relies on liquid cooling medium, forcing the system to integrate a heat pump function to meet the battery heating needs in low temperature environments. However, due to the limitations of refrigerant circulation characteristics and heat pump system energy efficiency, such direct cooling systems have inherent technical bottlenecks in low temperature heating conditions. Currently, the minimum effective operating environment temperature can only cover to about -15℃. In ultra-low temperature environments (-25℃ to -40℃), the traditional heat pump heating efficiency decreases significantly, and even cannot be started. This defect is particularly prominent in extremely cold regions, which is one of the key factors limiting its large-scale promotion. At the same time, the existing energy storage heat management systems generally have limited overall energy efficiency, complex system structure, high cost, poor battery cold plate uniformity and other shortcomings.

[0004] Therefore, it is necessary to provide an energy storage heat management system to overcome the deficiencies in the prior art. UTILITY MODEL CONTENTS

[0005] The utility model aims at providing an energy storage heat management system.

[0006] According to one aspect of the utility model, an energy storage heat management system is provided, comprising a compressor, a mode switching unit, a first heat exchanger, a second heat exchanger, a third heat exchanger, a fourth heat exchanger and a battery unit.

[0007] The outlet of the compressor is connected with the mode switching unit, the mode switching unit is also connected with the inlet of the compressor, the first heat exchanger, the second heat exchanger, the third heat exchanger and the fourth heat exchanger respectively, and a gas-liquid separator is arranged between the mode switching unit and the inlet of the compressor.

[0008] The working mode of the energy storage thermal management system includes a refrigeration mode and a heating mode;

[0009] In the heating mode, the refrigerant flows through the second heat exchanger, the battery unit, the fourth heat exchanger, the third heat exchanger, the mode switching unit and back to the compressor to complete a cycle, and is circulated by the compressor to complete a secondary cycle for heating.

[0010] In the refrigeration mode, the refrigerant flows through the first heat exchanger, the fourth heat exchanger, the battery unit, the fourth heat exchanger, the mode switching unit and back to the compressor to complete a cycle, and is circulated by the compressor to complete a secondary cycle for refrigeration.

[0011] Preferably, the third heat exchanger is an electric heating evaporator.

[0012] Preferably, the fourth heat exchanger includes a first passage and a second passage which are independent of each other and can exchange heat with each other.

[0013] The first port of the first heat exchanger is in communication with the mode switching unit through a pipeline, the second port of the first heat exchanger is in communication with the first passage through a pipeline, the first passage is in communication with the first port of the battery unit through a pipeline, the second port of the battery unit is in communication with the second passage through a pipeline, and the second passage is in communication with the mode switching unit through a pipeline.

[0014] The first port of the second heat exchanger is connected to the pipeline between the mode switching unit and the second passage through a pipeline, the second port of the second heat exchanger is connected to the pipeline between the second passage and the second port of the battery unit through a pipeline, the inlet of the third heat exchanger is connected to the pipeline between the first heat exchanger and the first passage through a pipeline, and the second port of the third heat exchanger is connected to the pipeline between the first heat exchanger and the mode switching unit through a pipeline.

[0015] Preferably, an electromagnetic valve is arranged at the first port of the first heat exchanger, a first one-way valve is arranged at the second port of the first heat exchanger to allow the refrigerant to flow to the first passage in one direction only, a second one-way valve is arranged at the second port of the second heat exchanger to allow the refrigerant to flow to the battery unit in one direction only, a third one-way valve is arranged at the second port of the third heat exchanger to allow the refrigerant to flow to the mode switching unit in one direction only, and a fourth one-way valve is arranged on the pipeline between the second passage and the mode switching unit to allow the refrigerant to flow to the mode switching unit in one direction only.

[0016] Preferably, an expansion valve and a liquid accumulator are arranged on the pipeline between the first passage and the battery unit, and the expansion valve is located between the first passage and the liquid accumulator.

[0017] Preferably, a first shut-off valve is arranged on the pipeline between the first port of the battery cell and the liquid accumulator, and a second shut-off valve is arranged on the pipeline between the connection of the second heat exchanger and the second passage and the second port of the battery cell.

[0018] Preferably, the mode switching unit comprises a four-way valve, and the four-way valve comprises a first valve port, a second valve port, a third valve port and a fourth valve port.

[0019] The outlet of the compressor is communicated with the first valve port, the inlet of the compressor is communicated with the third valve port, the first port of the first heat exchanger is communicated with the second valve port, the outlet of the third heat exchanger is communicated with the second valve port, the second passage is communicated with the fourth valve port, and the first port of the second heat exchanger is communicated with the fourth valve port.

[0020] In the heating mode, the first valve port is communicated with the fourth valve port, and the second valve port is communicated with the third valve port.

[0021] In the cooling mode, the first valve port is communicated with the second valve port, and the fourth valve port is communicated with the third valve port.

[0022] Preferably, the detection control unit comprises a controller, a pressure sensor and a temperature sensor which are arranged on the pipeline in the energy storage thermal management system and are electrically or signal connected with the controller.

[0023] Preferably, the pressure sensor comprises a first pressure sensor arranged at the outlet of the compressor, a second pressure sensor arranged at the inlet of the gas-liquid separator, a third pressure sensor arranged between the connection of the second heat exchanger and the second passage and the second shut-off valve, and a fourth pressure sensor arranged between the liquid accumulator and the first shut-off valve.

[0024] Preferably, the temperature sensor comprises a first temperature sensor arranged at the outlet of the compressor, a second temperature sensor arranged at the inlet of the gas-liquid separator, a third temperature sensor arranged between the connection of the second heat exchanger and the second passage and the second shut-off valve, and a fourth temperature sensor arranged between the liquid accumulator and the first shut-off valve.

[0025] Preferably, a first distributor arranged between the first shut-off valve and the battery cell and a second distributor arranged between the second shut-off valve and the battery cell are further arranged, the battery cell comprises a plurality of battery packs, and the distributors are used for uniformly distributing the refrigerant into each battery pack.

[0026] Compared with the prior art, the energy storage thermal management system has the following beneficial effects:

[0027] With the above technical scheme, the utility model discloses simple structure, clever design, low -cost advantage, third heat exchanger adopts electric heating evaporimeter, directly promotes refrigerant temperature through electric heating, need not rely on ambient temperature, avoid defrosting demand, can be at -40 ℃ Ambient temperature under stable heating, four heat exchangers are controlled in coordination, through the combination configuration of first to fourth heat exchanger, realize refrigeration / heating mode seamless switching, ensure that the liquid supply temperature fluctuation is less than ± 1 ℃, combine temperature sensor and pressure sensor detection's data, real -time regulation expansion valve opening degree and compressor speed, control the temperature difference between the battery cell in the battery unit within 1 within ℃, effectively control system temperature uniformity, and the energy efficiency is higher, the cost is lower, and the safety is stronger. BRIEF DESCRIPTION OF DRAWINGS

[0028] The utility model will be further explained in detail below in combination with the drawings and specific embodiment:

[0029] Figure 1 It is the structure schematic view of the energy storage thermal management system of the utility model embodiment;

[0030] Figure 2 It is the structure schematic view of the energy storage thermal management system of the utility model embodiment under refrigeration mode;

[0031] Figure 3 It is the structure schematic view of the energy storage thermal management system of the utility model embodiment under heating mode.

[0032] Among them, 10, compressor;11, gas-liquid separator;20, mode switching unit;201, four-way valve;a, first valve port;B, second valve port;C, third valve port;D, fourth valve port;301, first heat exchanger;302, second heat exchanger;303, third heat exchanger;304, fourth heat exchanger;3041, first passage;3042, second passage;40, battery unit;401, battery pack;50, electromagnetic valve;601, first check valve;602, second check valve;603, third check valve;604, fourth check valve;70, expansion valve;80, liquid accumulator;901, first stop valve;902, second stop valve;D1, first distributor;D2, second distributor;F1, first filter;F2, second filter;P1, first pressure sensor;P2, second pressure sensor;P3, third pressure sensor;P4, fourth pressure sensor;T1, first temperature sensor;T2, second temperature sensor;T3, third temperature sensor;T4, fourth temperature sensor;T5, fifth temperature sensor;T6, sixth temperature sensor. DETAILED DESCRIPTION

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description only represent some of the embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from these drawings without creative labor.

[0034] In order to make the drawing simple, only the parts related to the present application are shown in each drawing, which does not represent the actual structure of the product. In addition, in order to make the drawing simple and easy to understand, in some drawings, only one of the components with the same structure or function is shown, or only one of them is marked. In this paper, "one" not only means "only one", but also means "more than one".

[0035] It should be further understood that the term "and / or" used in the specification and claims of the present application means any combination of one or more of the associated listed items and all possible combinations, and includes these combinations.

[0036] In this paper, it should be noted that unless otherwise specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral connection; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through intermediate medium, or the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0037] In addition, in the description of the present application, the terms "first", "second" and the like are only used for differentiation and description, and cannot be understood as indicating or implying relative importance.

[0038] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will describe the specific embodiments of the present application with reference to the drawings. Obviously, the drawings in the following description only represent some of the embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from these drawings without creative labor, and other embodiments can also be obtained.

[0039] Referring to Figure 1 A kind of energy storage thermal management system, including compressor 10, mode switching unit 20, gas-liquid separator 11, first heat exchanger 301, second heat exchanger 302, third heat exchanger 303, fourth heat exchanger 304, battery unit 40, expansion valve 70 and reservoir 80.The working mode of energy storage thermal management system includes heating mode and refrigeration mode.

[0040] The compressor 10, the mode switching unit 20, the second heat exchanger 302, the battery unit 40, the liquid accumulator 80, the expansion valve 70, the fourth heat exchanger 304, the third heat exchanger 303, the mode switching unit 20 and the compressor 10 are sequentially connected by pipelines to form a heating circuit. The heating circuit is opened in the heating mode.

[0041] The compressor 10, the mode switching unit 20, the first heat exchanger 301, the fourth heat exchanger 304, the expansion valve 70, the liquid accumulator 80, the battery unit 40, the fourth heat exchanger 304, the mode switching unit 20 and the compressor 10 are sequentially connected by pipelines to form a cooling circuit. The cooling circuit is opened in the cooling mode.

[0042] The fourth heat exchanger 304 includes a first passage 3041 and a second passage 3042 which are independent of each other and can exchange heat with each other. The mode switching unit 20 selects a four-way valve 201. The four-way valve 201 includes a first valve port a, a second valve port b, a third valve port c and a fourth valve port d. In the heating mode, the first valve port a is in communication with the fourth valve port d, and the second valve port b is in communication with the third valve port c; in the cooling mode, the first valve port a is in communication with the second valve port b, and the fourth valve port d is in communication with the third valve port c.

[0043] Specifically, the four-way valve 201 changes the flow direction of the refrigerant, thereby realizing convenient switching between the cooling function and the heating function of the energy storage thermal management system.

[0044] The outlet of the compressor 10 is in communication with the first valve port a; the inlet of the compressor 10 is in communication with the third valve port c; the inlet of the first heat exchanger 301 is in communication with the second valve port b; the outlet of the third heat exchanger 303 is in communication with the second valve port b; the second passage 3042 is in communication with the fourth valve port d; and the inlet of the second heat exchanger 302 is in communication with the fourth valve port d.

[0045] A gas-liquid separator 11 is arranged between the third valve port c and the inlet of the compressor 10. The compressor 10 is used to pressurize the refrigerant and discharge the refrigerant in a high-temperature and high-pressure gaseous state. The gas-liquid separator 11 is used to separate the gas and the liquid.

[0046] In the cooling circuit, the inlet of the first heat exchanger 301 is in communication with the second valve port b of the mode switching unit 20 through a pipeline; the outlet of the first heat exchanger 301 is in communication with the first passage 3041 of the fourth heat exchanger 304 through a pipeline; the first passage 3041 is in communication with the first port of the battery unit 40 through a pipeline; the second port of the battery unit 40 is in communication with the second passage 3042 of the fourth heat exchanger 304 through a pipeline; and the second passage 3042 of the fourth heat exchanger 304 is in communication with the fourth valve port d of the mode switching unit 20 through a pipeline.

[0047] In the heating circuit, the inlet of the second heat exchanger 302 is connected by a pipe between the mode switching unit 20 and the second passage 3042, and the outlet of the second heat exchanger 302 is connected by a pipe between the second passage 3042 and the second port of the battery unit 40, that is, the second heat exchanger 302 is connected in parallel across the second passage 3042. The inlet of the third heat exchanger 303 is connected by a pipe between the first heat exchanger 301 and the first passage 3041, and the outlet of the third heat exchanger 303 is connected by a pipe between the first heat exchanger 301 and the mode switching unit 20, that is, the third heat exchanger 303 is connected in parallel across the first heat exchanger 301. The parallel connection can reduce the system resistance and thus reduce the power consumption of the entire machine.

[0048] The first port of the first heat exchanger 301 is provided with an electromagnetic valve 50. The second port of the first heat exchanger 301 is provided with a first one-way valve 601 for allowing the refrigerant to flow only in one direction to the first passage 3041; the second port of the second heat exchanger 302 is provided with a second one-way valve 602 for allowing the refrigerant to flow only in one direction to the battery unit 40; the second port of the third heat exchanger 303 is provided with a third one-way valve 603 for allowing the refrigerant to flow only in one direction to the mode switching unit 20; and the pipe between the second passage 3042 and the mode switching unit 20 is provided with a fourth one-way valve 604 for allowing the refrigerant to flow only in one direction to the mode switching unit 20. The provision of the one-way valves can ensure that the refrigerant does not accumulate in the heat exchangers that do not participate in the circulation during refrigeration or heating.

[0049] The expansion valve 70 and the accumulator 80 are both arranged on the pipe between the first passage 3041 and the battery unit 40, and the expansion valve 70 is located between the first passage 3041 and the accumulator 80. The pipe between the first port of the battery unit 40 and the accumulator 80 is provided with a first shut-off valve 901, and the pipe between the second port of the battery unit 40 and the connection between the second heat exchanger 302 and the second passage 3042 is provided with a second shut-off valve 902 (that is, the first shut-off valve 901 and the second shut-off valve 902 are arranged at the two ends of the battery unit 40, respectively). When the two shut-off valves are closed, the connection between the battery unit 40 and the energy storage thermal management system can be cut off. When the two shut-off valves are opened, the battery unit 40 can be connected to the energy storage thermal management system.

[0050] In the heating mode, the heating circuit is turned on, and the refrigerant flows through the compressor 10, the mode switching unit 20, the second heat exchanger 302, the second check valve 602, the second stop valve 902, the battery unit 40, the first stop valve 901, the liquid accumulator 80, the expansion valve 70, the first passage 3041 of the fourth heat exchanger 304, the third heat exchanger 303, the third check valve 603, the mode switching unit 20, the gas-liquid separator 11, and back to the compressor 10 to complete a cycle, and then through the compressor 10 to complete a secondary cycle of heating;

[0051] In the cooling mode, the cooling circuit is turned on, and the refrigerant flows through the compressor 10, the mode switching unit 20, the electromagnetic valve 50, the first heat exchanger 301, the first check valve 601, the first passage 3041 of the fourth heat exchanger 304, the expansion valve 70, the liquid accumulator 80, the first stop valve 901, the battery unit 40, the second passage 3042 of the fourth heat exchanger 304, the fourth check valve 604, the mode switching unit 20, the gas-liquid separator 11, and back to the compressor 10 to complete a cycle, and then through the compressor 10 to complete a secondary cycle of cooling.

[0052] The energy storage thermal management system of the embodiment further includes a detection control unit, which includes a controller, a pressure sensor arranged on a pipeline in the energy storage thermal management system and electrically or signal connected with the controller, and a temperature sensor.

[0053] The pressure sensor includes a first pressure sensor P1 arranged at the outlet of the compressor 10, a second pressure sensor P2 arranged at the inlet of the gas-liquid separator 11, a third pressure sensor P3 arranged between the second heat exchanger 302 and the second stop valve 902, and a fourth pressure sensor P4 arranged between the liquid accumulator 80 and the first stop valve 901.

[0054] The temperature sensor includes a first temperature sensor T1 arranged at the outlet of the compressor 10, a second temperature sensor T2 arranged at the inlet of the gas-liquid separator 11, a third temperature sensor T3 arranged between the second heat exchanger 302 and the second stop valve 902, and a fourth temperature sensor T4 arranged between the liquid accumulator 80 and the first stop valve 901. The system further includes a fifth temperature sensor T5 and a sixth temperature sensor T6, the fifth temperature sensor T5 is arranged near the first heat exchanger 301, and the sixth temperature sensor T6 is arranged on the third heat exchanger 303.

[0055] Referring to Figure 2 and Figure 3The battery unit 40 in the embodiment includes multiple groups of battery packs 401 arranged in parallel, and the battery unit 40 is connected in the energy storage thermal management system through a first distributor D1 and a second distributor D2. The first distributor D1 is arranged between the first stop valve 901 and the first port of the battery unit 40, and the second distributor D2 is arranged between the second stop valve 902 and the second port of the battery unit 40. That is, the collection port of the first distributor D1 is connected with the first stop valve 901, and the multiple distribution ports of the first distributor D1 are respectively connected with the first ports of the battery packs 401 in correspondence; the collection port of the second distributor D2 is connected with the second stop valve 902, and the multiple distribution ports of the second distributor D2 are respectively connected with the second ports of the battery packs 401 in correspondence. The distributor is used to uniformly distribute the refrigerant into the multiple battery packs 401, so that the multiple battery packs 401 can be synchronously heated or cooled, and meanwhile, the branch temperature of the refrigerant flowing into each battery pack 401 is similar, and the heat exchange effect of the multiple battery packs 401 is ensured to be the same.

[0056] The third heat exchanger 303 is an electric heating evaporator, which integrates a refrigerant flow channel, an electric heater and a spoiler. After the refrigerant absorbs the heat of the electric heater, the heat is transferred to the battery, and defrosting is not needed, so that the evaporator frosting phenomenon is avoided when the evaporator is operated under low temperature conditions, the heating capacity is stable, is not affected by the environment temperature, can stably heat under extremely low environment temperature, and the minimum environment temperature can be as low as -40℃.

[0057] When the temperature of the battery pack 401 collected by the upper computer is higher than the first preset temperature, the system starts the refrigeration mode. The low-temperature refrigerant gas (10℃-30℃) flows through the compressor 10 and is compressed into high-temperature and high-pressure gas (45℃-100℃) to the first valve port a of the four-way valve 201, and then flows out from the second valve port b to enter the first heat exchanger 301 through the electromagnetic valve 50. The outside of the pipeline of the first heat exchanger 301 is provided with a fan, and under the driving of the fan, the low-temperature outdoor air (-30℃-55℃) will flow through the outside of the pipeline of the first heat exchanger 301 and exchange heat with the high-temperature refrigerant in the pipeline. The high-temperature refrigerant in the pipeline is condensed into medium-temperature and high-pressure liquid (30℃-60℃). Then it flows through the first passage 3041 of the fourth heat exchanger 304 through the first check valve 601, and the medium-temperature and high-pressure refrigerant liquid continuously releases heat in the first passage 3041, and the temperature is further reduced to become low-temperature and high-pressure refrigerant liquid (to ensure that no refrigerant gas appears before entering the expansion valve 70). Then the refrigerant liquid enters the expansion valve 70 through the first filter F1, and under the action of the expansion valve 70, the low-temperature and high-pressure refrigerant liquid becomes low-temperature and low-pressure gas-liquid two-phase refrigerant (10℃-25℃) and flows through the second filter F2 to enter the accumulator 80. The accumulator 80 is provided with a first pipeline and a second pipeline, and the first pipeline and the second pipeline both directly extend to the bottom of the accumulator 80. The gas-liquid two-phase refrigerant enters the accumulator 80 through the first pipeline and gathers more refrigerant liquid at the bottom, and then more liquid refrigerant is discharged from the second pipeline of the accumulator 80 (at this time, there is more liquid refrigerant in the gas-liquid two-phase refrigerant, which is beneficial to the subsequent uniform distribution). Then the refrigerant passes through the stop valve and then the first distributor D1, and then uniformly enters the cold plate in each battery pack 401. The gas-liquid two-phase refrigerant evaporates and absorbs heat in the cold plate, becomes a gas with liquid state, and then flows out from the cold plate outlet, and then flows into the second passage 3042 of the fourth heat exchanger 304 through the second distributor D2. In the second passage 3042, the refrigerant exchanges heat with the medium-temperature and high-pressure refrigerant in the first passage 3041, continues to absorb heat, becomes a superheated gas state, and then flows out, and then enters the fourth valve port d of the four-way valve 201 through the fourth check valve 604, and then flows out from the third valve port c to enter the gas-liquid separator 11. The liquid refrigerant in the pipeline is further separated out through the gas-liquid separator 11 to ensure that the refrigerant entering the compressor 10 is in a full gas state. The refrigerant passing through the gas-liquid separator 11 is sucked into the compressor 10 to complete the refrigeration cycle, and then the above process is repeated.

[0058] When the temperature of the battery pack 401 collected by the host computer is lower than the second preset temperature, the system starts the heating mode. The low-temperature refrigerant gas (-10℃ ~ 20℃) flows to the first valve port a of the four-way valve 201 after being compressed by the compressor 10, and flows out from the fourth valve port d to enter the second heat exchanger 302. The second heat exchanger 302 is a pre-cooling heat exchanger. The outside of the pipeline of the second heat exchanger 302 is provided with a fan. Under the driving of the fan, the low-temperature outdoor air (-40℃ ~ 25℃) flows through the outside of the pipeline of the first heat exchanger 301 and exchanges heat with the high-temperature refrigerant in the pipeline. The high-temperature and high-pressure gaseous refrigerant in the pipeline changes into high-temperature and high-pressure saturated steam (30℃ ~ 45℃) after being cooled. Then, the saturated steam flows through the second check valve 602, the second stop valve 902 and the second distributor D2 module, and then evenly flows into the cold plate in each battery pack 401. The high-temperature and high-pressure saturated refrigerant steam continuously condenses and releases heat in the cold plate, and the temperature of the battery on the cold plate continuously rises after absorbing heat, slowly approaching the optimal working temperature state. The refrigerant changes into medium-temperature liquid (10℃ ~ 40℃) after releasing heat in the cold plate, and then flows through the first stop valve 901 into the liquid reservoir 80 after being converged by the first distributor D1. The refrigerant flowing out of the liquid reservoir 80 is in liquid state through the first pipeline and the second pipeline extending to the bottom of the liquid reservoir 80. Then, the liquid enters the expansion valve 70 through the second filter F2. Under the action of the expansion valve 70, the low-temperature and high-pressure refrigerant liquid changes into low-temperature and low-pressure gas-liquid two-phase refrigerant (-30℃ ~ -10℃) which flows through the first filter F1 and then enters the first passage 3041 of the fourth heat exchanger 304. Since the second passage 3042 of the fourth heat exchanger 304 is restricted by the fourth check valve 604 and no refrigerant flows, the refrigerant has no heat transfer when passing through the first passage 3041, and its state does not change. The refrigerant enters the third heat exchanger 303 after passing through the first passage 3041. The electric heating pipe in the third heat exchanger 303 continuously converts electric energy into heat and transfers it to the refrigerant. The refrigerant changes into superheated steam (-10℃ ~ 20℃) after absorbing the heat released by the electric heating, and then the superheated steam enters the second valve port b of the four-way valve 201 through the third check valve 603, and flows out from the third valve port c to enter the gas-liquid separator 11. After passing through the gas-liquid separator 11, the refrigerant steam is sucked into the compressor 10 to complete the heating cycle of the system. Thereafter, the above process is repeated.

[0059] In the system, the first temperature sensor T1 and the first pressure sensor P1 are used to detect the exhaust temperature and pressure of the compressor 10 respectively; the second temperature sensor T2 and the second pressure sensor P2 are used to detect the intake temperature and pressure of the compressor 10 respectively; the third temperature sensor T3 and the third pressure sensor P3 are used to detect the refrigerant temperature and pressure of the cold plate outlet in the refrigeration mode respectively; the fourth temperature sensor T4 and the fourth pressure sensor P4 are used to detect the refrigerant temperature and pressure of the cold plate inlet in the refrigeration mode respectively; the fifth temperature sensor T5 is used to detect the ambient temperature; and the sixth temperature sensor T6 is used to detect the temperature of the third heat exchanger 303, so as to avoid the thermal runaway of the third heat exchanger 303 due to excessively high temperature.

[0060] The detection parameters of each sensor are used for stable operation of the system.

[0061] It is obvious for those skilled in the art that various modifications and variations can be made to the above exemplary embodiments of the utility model without departing from the spirit and scope of the utility model. Therefore, it is intended to cover the modifications and variations of the utility model falling within the scope of the appended claims and their equivalents.

Claims

1. An energy storage thermal management system, characterized by, The energy storage thermal management system comprises a compressor, a mode switching unit, a first heat exchanger, a second heat exchanger, a third heat exchanger, a fourth heat exchanger and a battery unit. The outlet of the compressor is connected to the mode switching unit, and the mode switching unit is further connected to the inlet of the compressor, the first heat exchanger, the second heat exchanger, the third heat exchanger and the fourth heat exchanger respectively, and a gas-liquid separator is arranged between the mode switching unit and the inlet of the compressor. The working modes of the energy storage thermal management system include a refrigeration mode and a heating mode. In the heating mode, the refrigerant flows through the second heat exchanger, the battery unit, the fourth heat exchanger, the third heat exchanger, the mode switching unit and the compressor in sequence to complete a cycle, and is heated by the compressor for a second cycle. In the refrigeration mode, the refrigerant flows through the first heat exchanger, the fourth heat exchanger, the battery unit, the fourth heat exchanger, the mode switching unit and the compressor in sequence to complete a cycle, and is refrigerated by the compressor for a second cycle. The third heat exchanger is an electric heating evaporator.

2. The energy storage thermal management system of claim 1, wherein, The fourth heat exchanger comprises a first passage and a second passage which are independent of each other and can exchange heat with each other.

3. The energy storage thermal management system of claim 2, wherein, The first port of the first heat exchanger is connected to the mode switching unit through a pipeline, the second port of the first heat exchanger is connected to the first passage through a pipeline, the first passage is connected to the first port of the battery unit through a pipeline, the second port of the battery unit is connected to the second passage through a pipeline, and the second passage is connected to the mode switching unit through a pipeline. The first port of the second heat exchanger is connected to the pipeline between the mode switching unit and the second passage through a pipeline, the second port of the second heat exchanger is connected to the pipeline between the second passage and the second port of the battery unit through a pipeline, the inlet of the third heat exchanger is connected to the pipeline between the first heat exchanger and the first passage through a pipeline, and the second port of the third heat exchanger is connected to the pipeline between the first heat exchanger and the mode switching unit through a pipeline. An electromagnetic valve is arranged at the first port of the first heat exchanger, a first one-way valve is arranged at the second port of the first heat exchanger to allow the refrigerant to flow to the first passage in one direction only, a second one-way valve is arranged at the second port of the second heat exchanger to allow the refrigerant to flow to the battery unit in one direction only, a third one-way valve is arranged at the second port of the third heat exchanger to allow the refrigerant to flow to the mode switching unit in one direction only, and a fourth one-way valve is arranged on the pipeline between the second passage and the mode switching unit to allow the refrigerant to flow to the mode switching unit in one direction only.

4. The energy storage thermal management system of claim 3, wherein, An expansion valve and a liquid accumulator are arranged on the pipeline between the first passage and the battery unit, and the expansion valve is located between the first passage and the liquid accumulator.

5. The energy storage thermal management system of claim 4, wherein, A first stop valve is arranged on the pipeline between the first port of the battery unit and the liquid accumulator, and a second stop valve is arranged on the pipeline between the second port of the battery unit and the second passage of the second heat exchanger.

6. The energy storage thermal management system of claim 5, wherein, ​ 7. The energy storage thermal management system of claim 6, wherein, The mode switching unit comprises a four-way valve, the four-way valve comprises a first valve port, a second valve port, a third valve port and a fourth valve port; the outlet of the compressor is communicated with the first valve port, the inlet of the compressor is communicated with the third valve port, the first port of the first heat exchanger is communicated with the second valve port, the outlet of the third heat exchanger is communicated with the second valve port, the second passage is communicated with the fourth valve port, the first port of the second heat exchanger is communicated with the fourth valve port; In the heating mode, the first valve port is communicated with the fourth valve port, and the second valve port is communicated with the third valve port; In the cooling mode, the first valve port is communicated with the second valve port, and the fourth valve port is communicated with the third valve port.

8. The energy storage thermal management system of claim 7, wherein, Further comprising a detection control unit, the detection control unit comprises a controller, a pressure sensor and a temperature sensor which are arranged on the pipeline in the energy storage thermal management system and are electrically or signal connected with the controller.

9. The energy storage thermal management system of claim 8, wherein, The pressure sensor comprises a first pressure sensor arranged at the outlet of the compressor, a second pressure sensor arranged at the inlet of the gas-liquid separator, a third pressure sensor arranged between the connection of the second heat exchanger and the second passage and the second stop valve, and a fourth pressure sensor arranged between the liquid accumulator and the first stop valve.

10. The energy storage thermal management system of claim 9, wherein, The temperature sensor comprises a first temperature sensor arranged at the outlet of the compressor, a second temperature sensor arranged at the inlet of the gas-liquid separator, a third temperature sensor arranged between the connection of the second heat exchanger and the fourth heat exchanger and the second stop valve, and a fourth temperature sensor arranged between the liquid accumulator and the first stop valve.

11. The energy storage thermal management system of claim 10, wherein, Further comprising a first distributor arranged between the first stop valve and the battery unit and a second distributor arranged between the second stop valve and the battery unit, the battery unit comprises a plurality of battery packs, and the distributor is used for uniformly distributing the refrigerant into each battery pack. Further comprising a first distributor arranged between the first stop valve and the battery unit and a second distributor arranged between the second stop valve and the battery unit, the battery unit comprises a plurality of battery packs, and the distributor is used for uniformly distributing the refrigerant into each battery pack.

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