Direct cooling type heat management system, control method and energy storage system applying direct cooling type heat management system

Abstract

The invention discloses a direct-cooling type heat management system, a control method and an energy storage system applying the direct-cooling type heat management system, and relates to the technical field of heat management systems. A compressor, a condenser, a first evaporation heat exchanger, a second sub-throttling device and a second evaporation heat exchanger of the direct-cooling type heat management system are sequentially and circularly communicated to form a refrigerant circulation loop; a main throttling device is arranged behind the refrigerant output end of the condenser, and / or a first sub throttling device is arranged in front of the refrigerant input end of the first evaporation heat exchanger; the main throttling device is used for throttling refrigerants output by the condenser, the first sub-throttling device is used for throttling refrigerants entering the first evaporation heat exchanger, and the second sub-throttling device is used for throttling refrigerants entering the second evaporation heat exchanger. Accurate temperature control can be carried out on the battery pack and the power conversion device in the energy storage system, different thermal management requirements of the battery pack and the power conversion device are met, and the system has the advantages of being simple in scheme, high in energy efficiency value and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of thermal management systems, and in particular to a direct cooling thermal management system, a control method and an energy storage system using the same. Background Art

[0002] In the context of power system transformation and upgrading, the controllability and storability of electric energy has become one of the core of development. In this context, energy storage systems will also play the role of backup power supply and power supply to enhance the reliability of power systems and prevent accidental power outages. Energy storage systems based on lithium-ion batteries have the characteristics of flexible site selection, short construction period, and good regulation performance. At the same time, lithium-ion batteries themselves have high safety performance. The above characteristics make energy storage systems based on lithium-ion batteries widely used.

[0003] The power consumption of the auxiliary system is one of the important factors affecting the electricity-to-electricity conversion efficiency of the energy storage system. Experimental verification shows that the auxiliary system power consumption rate of the energy storage system based on lithium iron phosphate batteries is as high as more than 10%. The power consumption of the above-mentioned auxiliary system is mainly the cooling power consumption generated by the thermal management system. Therefore, the cooling power consumption generated by the thermal management system will reduce the overall electricity-to-electricity conversion efficiency of the energy storage system by about 5%.

[0004] The direct cooling thermal management system can directly exchange heat with the heat generating body of the energy storage system (especially the battery pack and the electric energy conversion device, etc.) through the evaporative heat exchanger. Compared with the thermal management system equipped with a liquid cooling unit (also known as "liquid-cooled air conditioner"), it can reduce the heat exchange efficiency loss of the liquid cooling medium, thereby improving the energy-saving effect of the thermal management system and the energy storage system, and reducing the cost of the thermal management system. In addition, the direct cooling thermal management system also has many advantages such as no need for regular maintenance of the liquid cooling medium, no need to recycle and process the liquid cooling medium, and no need to consider the leakage of the liquid cooling medium. Therefore, the direct cooling thermal management system has received widespread attention.

[0005] The direct cooling thermal management system in the prior art still has the following technical problems:

[0006] The power conversion devices in the energy storage system, such as the high-voltage circuit control unit (i.e., high-voltage box), converter (i.e., PCS) and inverter, will also generate heat during operation and also have thermal management requirements. For the thermal management system equipped with a liquid cooling unit, it can establish a liquid cooling medium branch to achieve thermal management of the power conversion device; however, the battery pack and the power conversion device in the energy storage system have different heating values ​​and temperature control requirements. If a direct cooling thermal management system is used directly and thermal management is performed on the battery pack and the power conversion device in the energy storage system at the same time, it is impossible to balance the different requirements between the battery pack and the power conversion device.

[0007] In summary, how to provide a reasonable direct cooling thermal management system and control method for the battery pack and power conversion device in the energy storage system has become one of the problems to be solved urgently. Summary of the invention

[0008] The object of the present invention is to provide a direct cooling thermal management system, a control method and an energy storage system using the same, which can provide a reasonable direct cooling thermal management system and a control method thereof for a battery pack and a power conversion device in the energy storage system.

[0009] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a direct cooling type thermal management system, used for thermal management of a first thermal management object and a second thermal management object in an energy storage system; the direct cooling type thermal management system comprises a compressor, a condenser with a fan, a first evaporative heat exchanger, a second sub-throttling device and a second evaporative heat exchanger; the compressor, the condenser, the first evaporative heat exchanger, the second sub-throttling device and the second evaporative heat exchanger are cyclically connected in sequence to form a refrigerant circulation loop; and a total throttling device is provided after the refrigerant output end of the condenser, and / or a first sub-throttling device is provided before the refrigerant input end of the first evaporative heat exchanger; the first evaporative heat exchanger can perform heat exchange with the first thermal management object, and the second evaporative heat exchanger can perform heat exchange with the second thermal management object; the total throttling device is used to throttle the refrigerant output from the condenser, the first sub-throttling device is used to throttle the refrigerant entering the first evaporative heat exchanger, and the second sub-throttling device is used to throttle the refrigerant entering the second evaporative heat exchanger.

[0010] In the above technical scheme, the direct cooling type thermal management system of the present invention also includes a refrigerant diverter; the first sub-throttling device and the first evaporative heat exchanger are configured in several groups; the total throttling device is connected to the refrigerant input end of the refrigerant diverter, and the several refrigerant output ends of the refrigerant diverter are respectively connected to each of the first sub-throttling devices, so as to distribute the refrigerant to each group of the first sub-throttling devices and the first evaporative heat exchanger to form several refrigerant branches; the refrigerant output ends of the first evaporative heat exchangers in each of the refrigerant branches are connected to the second sub-throttling device after merging.

[0011] In the above technical solution, after the refrigerant output end of the first evaporative heat exchanger, a refrigerant bypass return branch directly connected to the compressor is arranged.

[0012] In the above technical scheme, the direct cooling type thermal management system of the present invention also includes a refrigerant heat regenerator; after the refrigerant output end of the condenser, a refrigerant bypass heat recovery branch connected to one side of the refrigerant heat regenerator is further configured; the other side of the refrigerant heat regenerator is connected before the refrigerant input end of the compressor.

[0013] In the above technical solution, each of the refrigerant branches is connected to another refrigerant branch through at least one flow-sharing branch.

[0014] In the above technical solution, the first thermal management object in the energy storage system is a battery pack, and the second thermal management object in the energy storage system is a power conversion device.

[0015] In the above technical solution, the direct cooling thermal management system of the present invention further includes:

[0016] The pressure sensor P1 is connected after the refrigerant output end of the condenser;

[0017] A pressure sensor P2, which is connected to the refrigerant flow channel after the refrigerant output ends of the first evaporative heat exchangers in each of the refrigerant branches converge;

[0018] A pressure sensor P3 connected before the refrigerant input end of the compressor;

[0019] A temperature sensor T1 connected before the refrigerant input end of the refrigerant splitter;

[0020] A plurality of temperature sensors T2 are respectively connected after the refrigerant output end of the first evaporative heat exchanger in each of the refrigerant branches;

[0021] a temperature sensor Tout connected after the refrigerant output end of the second evaporative heat exchanger;

[0022] a temperature sensor Tcom connected before the refrigerant input end of the compressor;

[0023] And, an ambient temperature sensor Ta is used to detect the ambient temperature.

[0024] A control method for a direct cooling type thermal management system, which is applied to the above-mentioned direct cooling type thermal management system;

[0025] The control method includes:

[0026] The compressor runs, driving the refrigerant to sequentially pass through the compressor, the condenser, the total throttling device, the first sub-throttling device, the first evaporative heat exchanger, the second sub-throttling device and the second evaporative heat exchanger to complete the refrigerant circulation process;

[0027] During the refrigerant circulation process: the refrigerant output from the condenser is throttled by the total throttling device, the refrigerant entering the first evaporative heat exchanger is throttled by the first sub-throttling device, and the refrigerant entering the second evaporative heat exchanger is throttled by the second sub-throttling device.

[0028] In the above technical solution, the control method further comprises, during the refrigerant circulation process:

[0029] According to the pressure value fed back by the pressure sensor P1, the fan speed of the condenser is adjusted to maintain the outlet pressure of the condenser within a preset range;

[0030] According to the temperature value fed back by the temperature sensor Tcom and / or the pressure value fed back by the pressure sensor P3, the opening of the total throttling device is adjusted to maintain the return air temperature and / or return air pressure of the compressor within a preset range;

[0031] According to the pressure value fed back by the pressure sensor P2, the temperature value fed back by the ambient temperature sensor Ta, and the temperature values ​​fed back by each of the temperature sensors T2, the speed of the compressor is adjusted, and the opening of the corresponding first sub-throttling device is adjusted, so as to maintain the evaporation temperature and the outlet superheat of each of the first sub-throttling devices within a preset range;

[0032] According to the temperature value fed back by the temperature sensor Tout, the opening degree of the second sub-throttling device is adjusted to maintain the temperature of the second thermal management object within a preset range.

[0033] An energy storage system comprises the above-mentioned direct cooling thermal management system.

[0034] Compared with the prior art, the beneficial effects of the present invention are as follows: the direct cooling type thermal management system, control method and energy storage system using the same of the present invention, the first evaporative heat exchanger can exchange heat with the first thermal management object, the second evaporative heat exchanger can exchange heat with the second thermal management object, the total throttling device is used to throttle the refrigerant output by the condenser, the first sub-throttling device is used to throttle the refrigerant entering the first evaporative heat exchanger, and the second sub-throttling device is used to throttle the refrigerant entering the second evaporative heat exchanger; through a set of direct cooling type thermal management system, thermal management can be provided for the battery pack and the power conversion device in the energy storage system at the same time. Compared with the thermal management system equipped with a liquid cooling unit, the direct cooling type thermal management system of the present invention has the advantages of no need for regular maintenance of liquid cooling medium, no It has many advantages such as no need to recycle and process the liquid cooling medium and no need to consider the leakage of the liquid cooling medium, and it saves the cost of the liquid cooling unit. In the direct cooling type thermal management system of the present invention, the total throttling device is used to throttle the refrigerant output by the condenser, the first sub-throttling device is used to throttle the refrigerant entering the first evaporative heat exchanger, and the second sub-throttling device is used to throttle the refrigerant entering the second evaporative heat exchanger. In this way, the battery pack and the power conversion device in the energy storage system can be accurately controlled in temperature respectively to meet the different thermal management requirements of the battery pack and the power conversion device. In addition, the direct cooling type thermal management system, the control method and the energy storage system using the same of the present invention also have the characteristics of simple system solution and high energy efficiency value, which can effectively improve the reliability and service life of the energy storage system. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a system structure diagram of the direct cooling thermal management system in the present invention.

[0036] The accompanying drawings are marked as follows: 1. compressor; 2. condenser; 21. fan; 3. total throttling device; 4. refrigerant diverter; 5. first sub-throttling device; 6. first evaporative heat exchanger; 7. second sub-throttling device; 8. second evaporative heat exchanger; 9. refrigerant heat regenerator; 100. first thermal management object; 200. second thermal management object; 300. refrigerant branch; 400. equalizing branch; 500. refrigerant bypass return branch; 600. refrigerant bypass heat recovery branch. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] This embodiment provides a direct cooling thermal management system for performing thermal management on a first thermal management object and a second thermal management object in an energy storage system.

[0039] See also Figure 1 In this embodiment, the first thermal management object 100 in the energy storage system is a battery pack; the second thermal management object 200 in the energy storage system is a power conversion device, which includes a high-voltage circuit control unit (i.e., a high-voltage box) and a converter (i.e., a PCS).

[0040] See also Figure 1 The direct cooling thermal management system of this embodiment includes a compressor 1, a condenser 2 with a fan 21, a first evaporative heat exchanger 6, a second sub-throttling device 7 and a second evaporative heat exchanger 8.

[0041] The compressor 1, the condenser 2, the first evaporative heat exchanger 6, the second sub-throttling device 7 and the second evaporative heat exchanger 8 are circulated and connected in sequence to form a refrigerant circulation loop.

[0042] In addition, a total throttling device 3 is provided after the refrigerant output end of the condenser 2, and / or a first sub-throttling device 5 is provided before the refrigerant input end of the first evaporative heat exchanger 6; specifically, in a direct cooling type thermal management system, the total throttling device 3 can be provided separately, the first sub-throttling device 5 can be provided separately, or the total throttling device 3 and the first sub-throttling device 5 can be provided at the same time.

[0043] It should be noted that the connections between the above-mentioned components are all achieved through dedicated refrigerant pipelines.

[0044] The first evaporative heat exchanger 6 can exchange heat with the first thermal management object 100. Specifically, the first evaporative heat exchanger 6 is attached to the surface of the first thermal management object 100 or buried in the first thermal management object 100, so that it can directly absorb heat from the first thermal management object 100; the second evaporative heat exchanger 8 can exchange heat with the second thermal management object 200. Specifically, the second evaporative heat exchanger 8 is attached to the surface of the second thermal management object 200 or buried in the second thermal management object 200, so that it can directly absorb heat from the second thermal management object 200.

[0045] The total throttling device 3 is used to throttle the refrigerant output from the condenser 2 , the first sub-throttling device 5 is used to throttle the refrigerant entering the first evaporative heat exchanger 6 , and the second sub-throttling device 7 is used to throttle the refrigerant entering the second evaporative heat exchanger 8 .

[0046] Among them, the compressor 1 is a compressor used to compress refrigerant in a refrigeration system, preferably a variable frequency compressor; the condenser 2 is a condenser in the refrigeration system, which dissipates heat through its own fan 21, and the fan 21 is preferably an electronic fan that can accurately adjust the speed; the total throttling device 3, the first sub-throttling device 5 and the second sub-throttling device 7 are all throttling devices in the refrigeration system, preferably electronic expansion valves; the first evaporative heat exchanger 6 and the second evaporative heat exchanger 8 are both metal heat exchangers, which are provided with a refrigerant evaporation structure and are used as evaporators in the refrigeration system, and the first evaporative heat exchanger 6 and the second evaporative heat exchanger 8 can both realize heat exchange between low-temperature refrigerant and the heat management object. Specifically, the first evaporative heat exchanger 6 and the second evaporative heat exchanger 8 are both attached to the surface of the heat management object or buried in the heat management object, so that heat can be directly absorbed from the heat management object.

[0047] It can be understood that the direct cooling thermal management system of this embodiment also includes a host computer (such as a dedicated controller for the thermal management system, an energy storage system controller, an industrial control computer and a programmable controller, etc.), which is at least respectively connected to the compressor 1, the fan 21 of the condenser 2, the total throttling device 3, the first sub-throttling device 5 and the second sub-throttling device 7 by signal to adjust and control the above-mentioned components.

[0048] Furthermore, the direct cooling type thermal management system of the present embodiment further includes a refrigerant diverter 4, which has a refrigerant input end and a plurality of refrigerant output ends, and is used to distribute the refrigerant input to its refrigerant input end to the branches through each refrigerant output end; the first sub-throttling device 5 and the first evaporative heat exchanger 6 are configured in a plurality of groups, that is, a first sub-throttling device 5 cooperates with a first evaporative heat exchanger 6 to form a group; the total throttling device 3 is connected to the refrigerant input end of the refrigerant diverter 4 , several refrigerant output ends of the refrigerant diverter 4 are respectively connected to each first sub-throttling device 5, so as to distribute the refrigerant to each group of first sub-throttling devices 5 and the first evaporative heat exchanger 6, forming several refrigerant branches 300; the refrigerant output ends of the first evaporative heat exchangers 6 in each refrigerant branch 300 are converged and connected to the second sub-throttling device 7; it can be understood that, in each refrigerant branch 300, the first sub-throttling device 5 is used to throttle the refrigerant entering the first evaporative heat exchanger 6.

[0049] Furthermore, after the refrigerant output end of the first evaporative heat exchanger 6, a refrigerant bypass return branch 500 directly connected to the compressor 1 is provided; in the present embodiment, the refrigerant bypass return branch 500 is connected to the refrigerant flow path after the refrigerant output ends of the first evaporative heat exchanger 6 in each refrigerant branch 300 converge; the refrigerant bypass return branch 500 is provided to supply refrigerant to flow back to the refrigerant input end of the compressor 1 when the second sub-throttling device 7 is fully closed.

[0050] Furthermore, the direct cooling thermal management system of this embodiment also includes a refrigerant heat regenerator 9, wherein the refrigerant heat regenerator 9 (also called a "subcooler") is a metal component having at least two refrigerant channels, and heat exchange can occur between the two refrigerant channels of the refrigerant heat regenerator 9; after the refrigerant output end of the condenser 2, a refrigerant bypass heat recovery branch 600 connected to one side of the refrigerant heat regenerator 9 is further configured; the other side of the refrigerant heat regenerator 9 is connected before the refrigerant input end of the compressor 1.

[0051] Furthermore, in order to make the refrigerant state in each refrigerant branch 300 tend to be balanced, each refrigerant branch 300 is connected to another refrigerant branch 300 through at least one flow-sharing branch 400; Figure 1 As shown, in this embodiment, each refrigerant branch 300 is connected to another adjacent refrigerant branch 300 through a single flow-sharing branch 400 .

[0052] Furthermore, the direct cooling thermal management system of this embodiment also includes:

[0053] The pressure sensor P1 is connected after the refrigerant output end of the condenser 2;

[0054] A pressure sensor P2 connected to the refrigerant flow path after the refrigerant output ends of the first evaporative heat exchanger 6 in each refrigerant branch 300 converge;

[0055] A pressure sensor P3, which is connected before the refrigerant input end of the compressor 1;

[0056] The temperature sensor T1 is connected before the refrigerant input end of the refrigerant splitter 4;

[0057] A plurality of temperature sensors T2 are respectively connected after the refrigerant output end of the first evaporative heat exchanger 6 in each refrigerant branch 300;

[0058] A temperature sensor Tout connected after the refrigerant output end of the second evaporative heat exchanger 8;

[0059] A temperature sensor Tcom is connected before the refrigerant input end of the compressor 1;

[0060] And, an ambient temperature sensor Ta is used to detect the ambient temperature.

[0061] It can be understood that each of the above-mentioned sensors is connected to the host computer signal of the direct cooling type thermal management system; after setting the above-mentioned sensors, the host computer of the direct cooling type thermal management system can perform closed-loop control on the compressor 1, the fan 21 of the condenser 2, the total throttling device 3, the first sub-throttling device 5 and the second sub-throttling device 7 according to the pressure values ​​and temperature values ​​fed back by the above-mentioned sensors.

[0062] This embodiment also provides a control method of a direct cooling type thermal management system, which is applied to the above-mentioned direct cooling type thermal management system.

[0063] The control method includes:

[0064] The compressor 1 runs, driving the refrigerant to pass through the compressor 1, the condenser 2, the total throttling device 3, the first sub-throttling device 5, the first evaporative heat exchanger 6, the second sub-throttling device 7 and the second evaporative heat exchanger 8 in sequence to complete the refrigerant circulation process.

[0065] During the refrigerant circulation process: the refrigerant output from the condenser 2 is throttled by the total throttling device 3, the refrigerant entering the first evaporative heat exchanger 6 is throttled by the first sub-throttling device 5, and the refrigerant entering the second evaporative heat exchanger 8 is throttled by the second sub-throttling device 7.

[0066] Furthermore, in order to realize the closed-loop control of the direct cooling thermal management system, the control method further includes:

[0067] During the refrigerant circulation process:

[0068] According to the pressure value fed back by the pressure sensor P1, the speed of the fan 21 of the condenser 2 is adjusted to maintain the outlet pressure of the condenser 2 (directly measured by the pressure sensor P1) within a preset range;

[0069] According to the temperature value fed back by the temperature sensor Tcom and / or the pressure value fed back by the pressure sensor P3, the opening degree of the total throttling device 3 is adjusted to maintain the return air temperature (directly measured by the temperature sensor Tcom) and / or the return air pressure (directly measured by the pressure sensor P3) of the compressor 1 within a preset range;

[0070] According to the pressure value fed back by the pressure sensor P2, the temperature value fed back by the ambient temperature sensor Ta, and the temperature value fed back by each temperature sensor T2, the speed of the compressor 1 is adjusted, and the opening degree of the corresponding first sub-throttling device 5 is adjusted, so that the evaporation temperature and the outlet superheat (the evaporation temperature and the outlet superheat are obtained by calculation according to the pressure value fed back by the pressure sensor P2 and the temperature value fed back by the temperature sensor T2) of each first sub-throttling device 5 are maintained within a preset range;

[0071] According to the temperature value fed back by the temperature sensor Tout, the opening of the second sub-throttling device 7 is adjusted to maintain the temperature of the second thermal management object 200 (directly measured by the built-in temperature sensor of the second thermal management object 200) within a preset range.

[0072] This embodiment also provides an energy storage system, which includes the above-mentioned direct cooling thermal management system.

[0073] In the direct cooling type thermal management system, control method and energy storage system using the same in this embodiment, the first evaporative heat exchanger 6 can perform heat exchange with the first thermal management object 100, the second evaporative heat exchanger 8 can perform heat exchange with the second thermal management object 200, the total throttling device 3 is used to throttle the refrigerant output by the condenser 2, the first sub-throttling device 5 is used to throttle the refrigerant entering the first evaporative heat exchanger 6, and the second sub-throttling device 7 is used to throttle the refrigerant entering the second evaporative heat exchanger 8; through a set of direct cooling type thermal management system, thermal management can be provided for the battery pack and the power conversion device in the energy storage system at the same time. Compared with the thermal management system equipped with a liquid cooling unit, the direct cooling type thermal management system in this embodiment has the advantages of not requiring regular maintenance of the liquid cooling medium and not requiring recovery and processing Liquid cooling medium, no need to consider the leakage of liquid cooling medium and many other advantages, and saves the cost of liquid cooling unit; in the direct cooling type thermal management system of this embodiment, the total throttling device 3 is used to throttle the refrigerant output by the condenser 2, the first sub-throttling device 5 is used to throttle the refrigerant entering the first evaporative heat exchanger 6, and the second sub-throttling device 7 is used to throttle the refrigerant entering the second evaporative heat exchanger 8. In this way, the battery pack and the power conversion device in the energy storage system can be accurately controlled in temperature respectively to meet the different thermal management requirements of the battery pack and the power conversion device; in addition, the direct cooling type thermal management system, the control method and the energy storage system using the same of this embodiment also have the characteristics of simple system solution and high energy efficiency value, which can effectively improve the reliability and service life of the energy storage system.

[0074] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A direct cooling thermal management system, used for thermal management of a first thermal management object and a second thermal management object in an energy storage system; It is characterized in that It includes a compressor, a condenser with a fan, a first evaporative heat exchanger, a second sub-throttling device and a second evaporative heat exchanger; The compressor, the condenser, the first evaporative heat exchanger, the second sub-throttling device and the second evaporative heat exchanger are cyclically connected in sequence to form a refrigerant circulation loop; Furthermore, a total throttling device is provided after the refrigerant output end of the condenser, and / or a first sub-throttling device is provided before the refrigerant input end of the first evaporative heat exchanger; The first evaporative heat exchanger is capable of performing heat exchange with the first heat management object, and the second evaporative heat exchanger is capable of performing heat exchange with the second heat management object; The total throttling device is used to throttle the refrigerant output from the condenser, the first sub-throttling device is used to throttle the refrigerant entering the first evaporative heat exchanger, and the second sub-throttling device is used to throttle the refrigerant entering the second evaporative heat exchanger.

2. The direct cooling thermal management system according to claim 1, characterized in that: Also included is a refrigerant diverter; The first sub-throttling device and the first evaporative heat exchanger are configured in a plurality of groups; The main throttling device is connected to the refrigerant input end of the refrigerant splitter, and the refrigerant output ends of the refrigerant splitter are respectively connected to each of the first sub-throttling devices, so as to distribute the refrigerant to each group of the first sub-throttling devices and the first evaporative heat exchanger to form a plurality of refrigerant branches; The refrigerant output ends of the first evaporative heat exchangers in each of the refrigerant branches are connected to the second sub-throttling device after merging.

3. The direct cooling thermal management system according to claim 1 or 2, characterized in that: After the refrigerant output end of the first evaporative heat exchanger, a refrigerant bypass return branch directly connected to the compressor is arranged.

4. The direct cooling thermal management system according to claim 1 or 2, characterized in that: It also includes a refrigerant heat regenerator; After the refrigerant output end of the condenser, a refrigerant bypass heat recovery branch connected to one side of the refrigerant heat regenerator is further configured; The other side of the refrigerant heat regenerator is connected before the refrigerant input end of the compressor.

5. The direct cooling thermal management system according to claim 2, characterized in that: Each of the refrigerant branches is connected to another refrigerant branch through at least one flow-sharing branch.

6. The direct cooling thermal management system according to claim 1 or 2, characterized in that: The first thermal management object in the energy storage system is a battery pack, and the second thermal management object in the energy storage system is a power conversion device.

7. The direct cooling thermal management system according to claim 2, characterized in that: Also includes: The pressure sensor P1 is connected after the refrigerant output end of the condenser; A pressure sensor P2, which is connected to the refrigerant flow channel after the refrigerant output ends of the first evaporative heat exchangers in each of the refrigerant branches converge; A pressure sensor P3 connected before the refrigerant input end of the compressor; A temperature sensor T1 connected before the refrigerant input end of the refrigerant splitter; A plurality of temperature sensors T2 are respectively connected after the refrigerant output end of the first evaporative heat exchanger in each of the refrigerant branches; a temperature sensor Tout connected after the refrigerant output end of the second evaporative heat exchanger; a temperature sensor Tcom connected before the refrigerant input end of the compressor; And, an ambient temperature sensor Ta is used to detect the ambient temperature.

8. A control method for a direct cooling thermal management system, characterized in that: Applicable to the direct cooling thermal management system described in any one of claims 1 to 7; The control method includes: The compressor runs, driving the refrigerant to sequentially pass through the compressor, the condenser, the total throttling device, the first sub-throttling device, the first evaporative heat exchanger, the second sub-throttling device and the second evaporative heat exchanger to complete the refrigerant circulation process; During the refrigerant circulation process: the refrigerant output from the condenser is throttled by the total throttling device, the refrigerant entering the first evaporative heat exchanger is throttled by the first sub-throttling device, and the refrigerant entering the second evaporative heat exchanger is throttled by the second sub-throttling device.

9. The control method of the direct cooling type thermal management system according to claim 8, characterized in that: The direct cooling type thermal management system further includes a refrigerant diverter; The first sub-throttling device and the first evaporative heat exchanger are configured in a plurality of groups; The main throttling device is connected to the refrigerant input end of the refrigerant splitter, and the refrigerant output ends of the refrigerant splitter are respectively connected to each of the first sub-throttling devices, so as to distribute the refrigerant to each group of the first sub-throttling devices and the first evaporative heat exchanger to form a plurality of refrigerant branches; The refrigerant output ends of the first evaporative heat exchangers in each of the refrigerant branches are connected to the second sub-throttling device after merging; The direct cooling type thermal management system further comprises: The pressure sensor P1 is connected after the refrigerant output end of the condenser; A pressure sensor P2, which is connected to the refrigerant flow channel after the refrigerant output ends of the first evaporative heat exchangers in each of the refrigerant branches converge; A pressure sensor P3 connected before the refrigerant input end of the compressor; A temperature sensor T1 connected before the refrigerant input end of the refrigerant splitter; A plurality of temperature sensors T2 are respectively connected after the refrigerant output end of the first evaporative heat exchanger in each of the refrigerant branches; a temperature sensor Tout connected after the refrigerant output end of the second evaporative heat exchanger; a temperature sensor Tcom connected before the refrigerant input end of the compressor; and, an ambient temperature sensor Ta, for detecting ambient temperature; The control method also includes, During the refrigerant circulation process: According to the pressure value fed back by the pressure sensor P1, the fan speed of the condenser is adjusted to maintain the outlet pressure of the condenser within a preset range; According to the temperature value fed back by the temperature sensor Tcom and / or the pressure value fed back by the pressure sensor P3, the opening of the total throttling device is adjusted to maintain the return air temperature and / or return air pressure of the compressor within a preset range; According to the pressure value fed back by the pressure sensor P2, the temperature value fed back by the ambient temperature sensor Ta, and the temperature values ​​fed back by each of the temperature sensors T2, the speed of the compressor is adjusted, and the opening of the corresponding first sub-throttling device is adjusted, so as to maintain the evaporation temperature and the outlet superheat of each of the first sub-throttling devices within a preset range; According to the temperature value fed back by the temperature sensor Tout, the opening degree of the second sub-throttling device is adjusted to maintain the temperature of the second thermal management object within a preset range.

10. An energy storage system, characterized in that: It includes the direct cooling thermal management system described in any one of claims 1-7.

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