A thermal management system for a container energy storage device

Abstract

The present application discloses a thermal management system for a container energy storage device, which includes a battery cluster, which includes multiple PACKs. The thermal management system includes a first liquid storage tank, a second liquid storage tank, and a flow distribution valve. The first liquid storage tank is used to store refrigerant. The first liquid storage tank and the second liquid storage tank are connected by a first pipeline. The second pipeline has a main pipe and multiple branches connected to the main pipe. The end of the main pipe away from the branch pipe is connected to the second liquid storage tank, and the end of the branch pipe away from the main pipe is used to connect to the multiple PACKs of the battery cluster respectively. The flow distribution valve is arranged on the branch pipe of the second pipeline. The refrigerant is first diverted to the second liquid storage tank and then distributed to each PACK of the battery cluster through the flow distribution valve, and the refrigerant undergoes phase change in the PACK to exchange heat. The refrigerant undergoes phase change and heat exchange directly in the cold plate of the PACK, which greatly improves the heat exchange efficiency and energy utilization, and also improves the thermal management efficiency of the container energy storage device.

Description

Technical Field

[0001] The present invention relates to a battery refrigerant thermal management system, and in particular to a thermal management system for a container energy storage device. Background Art

[0002] A containerized battery system consists of multiple battery cells (battery clusters) stored and managed within a container. This type of battery system is commonly used in energy storage, for grid load balancing, addressing peak and valley power demand, providing backup power, and storing renewable energy. Containerized battery systems typically offer high capacity and flexibility.

[0003] Each battery cell (battery cluster) of a containerized battery system includes multiple PACK packages, each of which is equipped with a cold plate, and a water-cooling pipe is installed in the cold plate. The thermal management of existing containerized battery systems is mainly achieved by using water-cooling pipes and the cooling water in the water-cooling pipes. The cooling water first exchanges heat through the heat exchanger of the chiller and then flows through the water-cooling pipes to participate in the thermal management of the PACK package (cooling the PACK package). This thermal management system that uses cooling water for heat exchange has low heat exchange efficiency and low energy utilization. Summary of the Invention

[0004] In response to the above problems, the present invention proposes a thermal management system for a container energy storage device.

[0005] The technical solution adopted by the present invention is as follows:

[0006] The present application provides a thermal management system for a container energy storage device, wherein the container energy storage device includes a battery cluster, and the battery cluster includes a plurality of PACKs;

[0007] The thermal management system includes a first liquid storage tank, a second liquid storage tank, a flow distribution valve, a first pipeline and a second pipeline;

[0008] The first liquid storage tank is used to store refrigerant;

[0009] The first liquid storage tank and the second liquid storage tank are connected via a first pipeline. The second pipeline includes a main pipe and a plurality of branch pipes connected to the main pipe. An end of the main pipe away from the branch pipe is connected to the second liquid storage tank. An end of the branch pipe away from the main pipe is used to be connected to the plurality of PACKs of the battery cluster respectively.

[0010] The flow distribution valve is provided on the branch pipe of the second pipeline, and is used to control the refrigerant flow of the branch pipe so that the flow is evenly distributed in each PACK;

[0011] The thermal management system includes a battery management controller;

[0012] The control logic of the thermal management system includes:

[0013] The battery management controller collects NTC temperature measurement information inside the PACK package, numbers and analyzes the collected NTC temperature measurement information; each PACK package has multiple NTC temperature measurement points, and the NTC temperature measurement information includes temperature values ​​at multiple different locations within each PACK package; when numbering the NTC temperature measurement information, it is numbered in sequence according to the hierarchy of battery clusters and PACK packages. The temperature difference within the cluster refers to the difference between the maximum and minimum temperature values ​​in all NTC temperature measurement data of all PACK packages in the same battery cluster.

[0014] The battery management controller calculates and determines the temperature difference within the cluster:

[0015] When the temperature difference within the cluster is less than or equal to a first value, the battery management controller controls each flow distribution valve to operate according to a default opening number, and the first value range is between 0°C and 5°C. At this time, the thermal management system works normally, that is, the battery management controller continues to collect and judge the NTC temperature measurement information. At the same time, when the flow distribution valve on one branch pipe is opened, the flow distribution valves on the other branches are closed;

[0016] When the temperature difference within the cluster is greater than the first value, the thermal management system performs response control: the battery management controller determines the battery cluster position, the position of the corresponding high-temperature PACK package within the cluster, and the position of the corresponding flow distribution valve, and recalculates and determines the difference between the temperature difference within the cluster and the first value:

[0017] When the difference is less than or equal to 1°C, the battery management controller controls to extend the opening time of the flow distribution valve corresponding to the high-temperature PACK package or continuously increase the opening times;

[0018] When the difference is greater than 1°C and less than the first value, the battery management controller controls to extend the opening time of the flow distribution valve corresponding to the high-temperature PACK package or continuously increase the number of openings, and the extended opening time or the continuously increased number of openings at this time are respectively greater than the extended opening time or the continuously increased number of openings when the difference is less than or equal to 1°C;

[0019] When the difference is greater than the first value, the battery management controller reports a fault and the system shuts down. At this time, the battery is not allowed to charge or discharge, while the refrigeration system continues to work. The battery management controller collects and judges the NTC temperature measurement information inside the PACK package until the temperature difference at the NTC temperature measurement point is less than the first value temperature.

[0020] In actual use, the PACK is equipped with multiple temperature sensors, each containing a negative temperature coefficient thermistor (NTC). The battery management controller is electrically connected to the temperature sensors. As the number of openings increases or the corresponding flow distribution valve remains open for a longer period, the refrigerant's heat exchange efficiency within the PACK improves until the internal temperature difference within the PACK reaches a normal range. The corresponding flow distribution valve maintains the default opening number.

[0021] The thermal management system provided by the present application sets a first liquid storage tank as the main liquid storage tank, and first diverts the refrigerant in the main liquid storage tank to the second liquid storage tank for buffering, and then distributes the refrigerant in the second liquid storage tank to each PACK package of the battery cluster through the flow distribution valve, and causes the refrigerant to undergo phase change in the PACK package for heat exchange, so as to achieve thermal management of the PACK package and the container energy storage device. Compared with the existing water-cooled thermal management system, under the same conditions, the present application reduces the heat exchange between the water channel and the refrigerant, and allows the refrigerant to directly undergo phase change heat exchange in the cold plate of the PACK package, thereby improving the energy utilization rate of the refrigerant or refrigerant, and greatly improving the heat exchange efficiency. The control method combined with the flow distribution valve can also improve the thermal management efficiency of the container energy storage device.

[0022] In actual use, the default opening times are set as needed according to the size of the container energy storage device and the usage of the internal PACK package.

[0023] During normal operation, the flow distribution valves on each branch pipe open and close sequentially, and each valve is open for the same length of time. That is, after the previous flow distribution valve opens for a period of time and then closes, the next flow distribution valve opens and closes for the same period of time, and so on, in a cycle that ensures even flow distribution within each pack.

[0024] Furthermore, the battery clusters include a plurality of battery clusters, the second liquid storage tanks include a plurality of second liquid storage tanks, and the plurality of second liquid storage tanks are respectively provided corresponding to the plurality of battery clusters.

[0025] When a single battery cluster requires thermal management, the second liquid storage tank corresponding to this battery cluster is independently mobilized, and the other second liquid storage tanks are not affected.

[0026] Furthermore, it also includes a flow control valve and a pressure sensor, wherein the flow control valve is arranged on the first pipeline, and the pressure sensor is arranged inside the second liquid storage tank;

[0027] The flow control valve is electrically connected to the pressure sensor. When the pressure sensor senses that the internal pressure of the second liquid storage tank is less than the saturated vapor pressure of the refrigerant, the flow control valve opens.

[0028] When the pressure sensor senses that the pressure inside the second liquid storage tank is less than the saturated vapor pressure of the refrigerant, the flow control valve opens, injecting refrigerant into the second liquid storage tank, increasing the pressure inside the second liquid storage tank to ensure that the pressure inside the second liquid storage tank is greater than or equal to the saturated vapor pressure of the refrigerant, thereby ensuring that the refrigerant in the second liquid storage tank is always in a liquid state. When the pressure sensor senses that the pressure inside the second liquid storage tank reaches the set value, the flow control valve closes.

[0029] Furthermore, the first pipeline includes multiple first pipelines, and the multiple first pipelines are respectively used to connect the multiple second liquid storage tanks to the first liquid storage tank respectively, and the flow control valves on each first pipeline are respectively connected to the electrical signals of the pressure sensors in the corresponding second liquid storage tanks.

[0030] In actual use, the multiple first pipelines can also be configured as a structure in which the first pipeline has multiple branch pipelines.

[0031] Furthermore, the flow control valve is an electrically controlled valve.

[0032] Furthermore, the flow distribution valve is a solenoid valve.

[0033] Furthermore, the flow distribution valve is a high-frequency electromagnetic valve, and the opening time of the high-frequency electromagnetic valve is a millisecond-level response.

[0034] The high-frequency solenoid valve is also used to separate the refrigerant from gas and liquid, filtering out some of the gaseous refrigerant that has undergone phase change, so that the refrigerant flowing into the PACK cold plate is liquid.

[0035] The high-frequency solenoid valve has a fast response speed and a short response time, so as to improve the management and control efficiency of the thermal management system.

[0036] Furthermore, it also includes a pressure buffer device, which is arranged on the branch pipe of the second pipeline and is located between the flow distribution valve and the PACK package.

[0037] Furthermore, the pressure buffer device is an expansion joint, a shock-absorbing pipe or a post-valve buffer tank.

[0038] In actual use, after the high-frequency solenoid valve is set, pressure fluctuations will be generated in the refrigerant fluid in the pipeline behind the valve, and vibration will be generated when the high-frequency solenoid valve works at a high frequency. The pressure buffer device is used to alleviate this adverse effect.

[0039] Expansion joints are made of metal and have a certain degree of elasticity and flexibility. They can move relatively in the piping system, thereby reducing the pressure or stress generated in the piping system.

[0040] Shock absorbers reduce the impact and stress on piping systems when they are subjected to external shock or vibration. They are made of a flexible metal braid with an internal shock-absorbing layer to absorb shock and vibration, and have a certain degree of elasticity and flexibility to relieve twisting or displacement of the piping system.

[0041] A post-valve buffer tank is a gas-liquid separation tank used to buffer liquid pressure fluctuations in a pipeline system, especially when gas is present. This tank's function is to store capacity to mitigate pressure fluctuations when liquid flows into or out of the pipeline, thereby maintaining a stable pressure in the system.

[0042] Furthermore, it also includes a refrigeration system, the outlet of the refrigeration system is connected to the inlet of the first liquid storage tank.

[0043] Furthermore, a third pipeline is included, one end of which is connected to the outlet of the PACK package, and the other end is connected to the inlet of the refrigeration system.

[0044] After being compressed and condensed in the refrigeration system, the refrigerant continues to participate in the heat exchange of the next PACK. During the condensation process, the refrigerant exchanges heat with the air through the refrigeration system.

[0045] Furthermore, one end of the third pipeline connected to the outlet of the container energy storage device has multiple branch pipelines, and the multiple branch pipelines are respectively used to connect to the corresponding outlets of multiple battery clusters in the container energy storage device.

[0046] After the refrigerant passes through the PACK for heat exchange, it flows back to the refrigeration system through the third pipe and circulates again after being cooled. In actual use, the refrigerant can be ammonia, Freon or carbon dioxide.

[0047] The beneficial effects of the present invention are:

[0048] (1) The thermal management system provided by the present application sets a first liquid storage tank as the main liquid storage tank, and first diverts the refrigerant in the main liquid storage tank to the second liquid storage tank for buffering, and then distributes the refrigerant in the second liquid storage tank to each PACK package of the battery cluster through the flow distribution valve, and causes the refrigerant to undergo phase change in the PACK package for heat exchange, thereby achieving thermal management of the PACK package and the container energy storage device. Compared with the existing water-cooled thermal management system, under the same conditions, the present application reduces the heat exchange between the water channel and the refrigerant, and allows the refrigerant to directly undergo phase change heat exchange in the cold plate of the PACK package, thereby improving the energy utilization rate of the refrigerant or refrigerant, and greatly improving the heat exchange efficiency, and can also improve the thermal management efficiency of the container energy storage device.

[0049] (2) The flow distribution valves on each branch pipe open and close in sequence, and at the same time, the length of time each flow distribution valve is open is the same. That is, after the previous flow distribution valve opens for a period of time and then closes, the next flow distribution valve opens and closes for the same period of time, and the cycle continues in sequence, so that the flow in each PACK is evenly distributed. Combined with the high frequency of the high-speed solenoid valve, the uniformity of the fluid in the flow channel after the valve can also be guaranteed to a large extent.

[0050] (3) A flow control valve is provided on the first pipeline, and a pressure sensor is provided in the second liquid storage tank. The flow control valve and the pressure sensor cooperate to ensure that the refrigerant in the second liquid storage tank is always in a liquid state. A high-frequency solenoid valve is provided on the second pipeline to separate the refrigerant from gas and liquid, so that the refrigerant flowing into the PACK cold plate is in a liquid state. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 This is a schematic diagram of the structure of a thermal management system of a multi-container energy storage device according to an embodiment of the present invention;

[0052] Figure 2 is a control logic diagram of a thermal management system according to an embodiment of the present invention;

[0053] Figure 3 Schematic diagram of the working conditions of each flow distribution valve in an embodiment of the present invention (normal operation);

[0054] Figure 4 Schematic diagram of the working conditions of each flow distribution valve in an embodiment of the present invention (response control work);

[0055] Figure 5 Schematic diagram of the working conditions of each flow distribution valve in an embodiment of the present invention (response control work).

[0056] The reference numerals in the figures are:

[0057] 10. First liquid storage tank; 20. Battery cluster; 210. PACK package; 211. First PACK package; 212. Second PACK package; 213. Third PACK package; 214. Fourth PACK package; 30. Second liquid storage tank; 310. Pressure sensor; 40. First pipeline; 410. Flow control valve; 50. Second pipeline; 501. Main pipe; 502. Branch pipe; 510. Flow distribution valve; 511. Valve A; 512. Valve B; 513. Valve C; 514. Valve D; 60. Refrigeration system; 70. Third pipeline. DETAILED DESCRIPTION

[0058] The present invention will be described in detail below with reference to the accompanying drawings.

[0059] Example 1

[0060] like Figure 1 As shown, the present application provides a thermal management system for a container energy storage device, wherein the container energy storage device includes two battery clusters 20, each of which includes four PACK packages 210.

[0061] The thermal management system includes a first liquid storage tank 10, a second liquid storage tank 30, a flow distribution valve 510, a first pipeline 40 and a second pipeline 50;

[0062] The first liquid storage tank 10 is used to store refrigerant;

[0063] The first liquid storage tank 10 and the second liquid storage tank 30 are connected via a first pipe 40. The second pipe 50 includes a main pipe 501 and four branch pipes 502 connected to the main pipe 501. The end of the main pipe 501 away from the branch pipe 502 is connected to the second liquid storage tank 30. The end of the branch pipe 502 away from the main pipe 501 is used to connect to the four PACKs 210 of the battery cluster 20 respectively.

[0064] The flow distribution valve 510 is provided on the branch pipe 502 of the second pipeline 50;

[0065] The thermal management system includes a battery management controller (not shown);

[0066] like Figure 2 As shown, the control logic of the thermal management system includes:

[0067] The battery management controller collects NTC temperature measurement information inside the PACK package, numbers and analyzes the collected NTC temperature measurement information; each PACK package has multiple NTC temperature measurement points, and the NTC temperature measurement information includes temperature values ​​at multiple different locations within each PACK package; when numbering the NTC temperature measurement information, it is numbered in sequence according to the hierarchy of battery clusters and PACK packages. The temperature difference within the cluster refers to the difference between the maximum and minimum temperature values ​​in all NTC temperature measurement data of all PACK packages in the same battery cluster.

[0068] The battery management controller calculates and determines the difference between the temperature difference within the cluster and the first value set, which is set to 4°C:

[0069] When the temperature difference within the cluster is less than or equal to the first value, the battery management controller controls each flow distribution valve to operate according to the default opening times. At this time, the thermal management system operates normally, that is, the battery management controller continues to collect and judge the NTC temperature measurement information. When the flow distribution valve on one branch pipe is opened, the flow distribution valves on the other branches are closed.

[0070] When the temperature difference within the cluster is greater than the first value, the thermal management system performs response control: the battery management controller determines the battery cluster position, the position of the corresponding high-temperature PACK package within the cluster, and the position of the corresponding flow distribution valve, and recalculates and determines the difference between the temperature difference within the cluster and the first value:

[0071] When the difference is less than or equal to 1°C, the battery management controller controls the continuous increase in the number of times the flow distribution valve corresponding to the high-temperature PACK is opened. In this embodiment, it is increased by 1 time. In other embodiments, it can be increased by 2 times or the opening time of the corresponding flow distribution valve can be extended, specifically by 0.1 seconds.

[0072] When the difference is greater than 1°C and less than 4°C, the battery management controller controls the continuous increase in the number of openings of the flow distribution valve corresponding to the high-temperature PACK package. In this embodiment, the increase is 2 times. In other embodiments, the increase is 3 times or the opening time of the corresponding flow distribution valve is extended, specifically by 0.2 seconds.

[0073] When the difference is greater than the first value (i.e., the temperature difference within the cluster is greater than 8°C), the battery management controller reports a fault and the system shuts down. At this time, battery charging and discharging are not allowed, while the refrigeration system continues to work. The battery management controller collects and judges the NTC temperature measurement information inside the PACK package until the temperature difference at the NTC temperature measurement point is less than the first value temperature.

[0074] In other embodiments, the container energy storage device includes three or more battery clusters. In actual use, one battery cluster corresponds to one second liquid storage tank.

[0075] In other embodiments, the first value may be set to 3°C or 5°C.

[0076] In actual use, the PACK is equipped with multiple temperature sensors, each of which is equipped with a negative temperature coefficient thermistor (NTC). The battery management controller is electrically connected to the temperature sensors. As the number of openings increases or the corresponding flow distribution valve opening time is extended, the refrigerant heat exchange efficiency in the PACK improves, until the temperature difference within the PACK reaches a normal value range. The corresponding flow distribution valve maintains the default opening number. In this embodiment, the default opening number is 5, indicating that each flow distribution valve opens and closes five times in sequence within one second, with each opening duration of 0.05 seconds.

[0077] The thermal management system provided by the present application sets a first liquid storage tank 10 as the main liquid storage tank, and first diverts the refrigerant in the main liquid storage tank to the second liquid storage tank 30 for buffering, and then distributes the refrigerant in the second liquid storage tank 30 to each PACK package 210 of the battery cluster 20 through the flow distribution valve 510, and causes the refrigerant to undergo phase change in the PACK package 210 for heat exchange, so as to achieve thermal management of the PACK package 210 and the container energy storage device. Compared with the existing water-cooled thermal management system, under the same conditions, the present application reduces the heat exchange between the water channel and the refrigerant, and allows the refrigerant to directly undergo phase change heat exchange in the cold plate of the PACK package, thereby improving the energy utilization rate of the refrigerant or refrigerant, and greatly improving the heat exchange efficiency, and can also improve the thermal management efficiency of the container energy storage device.

[0078] During normal operation, the flow distribution valves 510 on each branch pipe 502 open and close sequentially, and the duration of each flow distribution valve 510 opening is the same. That is, after the previous flow distribution valve 510 opens and closes for a period of time, the next flow distribution valve 510 opens and closes for the same period of time, and this cycle continues, ensuring uniform flow distribution within each PACK 210.

[0079] In this embodiment, the thermal management system is a refrigerant direct cooling thermal management system.

[0080] In this embodiment, there are two second liquid storage tanks 30 , and the two second liquid storage tanks 30 are respectively disposed corresponding to the two battery clusters 20 .

[0081] When a single battery cluster 20 requires thermal management, the second liquid storage tank 30 corresponding to this battery cluster 20 is independently mobilized, and the other second liquid storage tanks 30 are not affected.

[0082] In this application, the first pipeline 40 is a primary pipeline, the main pipe 501 of the second pipeline 50 is a secondary pipeline, and the branch pipe 502 of the first pipeline 40 is a tertiary pipeline. The refrigerant flows through the primary pipeline, the secondary pipeline, and the tertiary pipeline in sequence to participate in thermal management.

[0083] In this embodiment, a flow control valve 410 and a pressure sensor 310 are further included. The flow control valve 410 is disposed on the first pipeline 40 , and the pressure sensor 310 is disposed inside the second liquid storage tank 30 .

[0084] The flow control valve 410 is electrically connected to the pressure sensor 310 . When the pressure sensor 310 senses that the internal pressure of the second liquid storage tank 30 is lower than the saturated vapor pressure of the refrigerant, the flow control valve 410 opens.

[0085] When the pressure sensor 310 senses that the pressure inside the second liquid storage tank 30 is less than the saturated vapor pressure of the refrigerant, the flow control valve 410 opens, injecting refrigerant into the second liquid storage tank 30 and increasing the pressure inside the second liquid storage tank 30 to ensure that the pressure inside the second liquid storage tank 30 is greater than or equal to the saturated vapor pressure of the refrigerant, thereby ensuring that the refrigerant in the second liquid storage tank 30 is always in a liquid state. When the pressure sensor 310 senses that the pressure inside the second liquid storage tank 30 reaches the set value, the flow control valve 410 closes.

[0086] In this embodiment, the first pipeline 40 includes two, and the two first pipelines 40 are respectively used to connect the two second liquid storage tanks 30 to the first liquid storage tank 10 respectively, and the flow control valve 410 on each first pipeline 40 is respectively electrically connected to the pressure sensor 310 in the corresponding second liquid storage tank 30.

[0087] In actual use, the two first pipelines 40 may also be configured as a structure in which the first pipeline 40 has two branch pipelines.

[0088] In this embodiment, the flow control valve 410 is an electrically controlled valve.

[0089] In this embodiment, the flow distribution valve 510 is a solenoid valve.

[0090] In this embodiment, the flow distribution valve 510 is a high-frequency solenoid valve, and the opening time of the high-frequency solenoid valve is a millisecond-level response.

[0091] The high-frequency solenoid valve is also used to separate the refrigerant from gas and liquid, filtering out some of the gaseous refrigerant that has undergone phase change, so that the refrigerant flowing into the PACK cold plate is liquid.

[0092] The high-frequency solenoid valve has a fast response speed and a short response time, so as to improve the management and control efficiency of the thermal management system.

[0093] In this embodiment, a pressure buffer device (not shown) is further included. The pressure buffer device is disposed on the branch pipe 502 of the second pipeline 50 and is located between the flow distribution valve 510 and the PACK package 210 .

[0094] In this embodiment, the pressure buffer device is a corrosion-resistant expansion joint, a shock-absorbing pipe, or a post-valve buffer tank.

[0095] In actual use, after the high-frequency solenoid valve is set, pressure fluctuations will be generated in the refrigerant fluid in the pipeline behind the valve, and vibration will be generated when the high-frequency solenoid valve works at a high frequency. The pressure buffer device is used to alleviate this adverse effect.

[0096] Expansion joints are made of metal materials and can move relative to each other in the piping system, thereby reducing the pressure or stress generated in the piping system.

[0097] Shock absorbers reduce the impact and stress on piping systems when they are subjected to external shock or vibration. They are made of a flexible metal braid with an internal shock-absorbing layer to absorb shock and vibration, and have a certain degree of elasticity and flexibility to relieve twisting or displacement of the piping system.

[0098] A post-valve buffer tank is a gas-liquid separation tank used to buffer liquid pressure fluctuations in a pipeline system, especially when gas is present. This tank's function is to store capacity to mitigate pressure fluctuations when liquid flows into or out of the pipeline, thereby maintaining a stable pressure in the system.

[0099] In this embodiment, a refrigeration system 60 is further included, and an outlet of the refrigeration system 60 is connected to the inlet of the first liquid storage tank 10 .

[0100] In this embodiment, a third pipe 70 is further included. One end of the third pipe 70 is connected to the outlet of the PACK package 210 , and the other end of the third pipe 70 is connected to the inlet of the refrigeration system 60 .

[0101] In this embodiment, one end of the third pipeline 70 connected to the outlet of the container energy storage device has four branch pipelines. The four branch pipelines are respectively used to connect to the outlets of the four PACKs 210 in the battery cluster 20 .

[0102] After the refrigerant passes through the PACK 210 for heat exchange, it flows back to the refrigeration system 60 through the third pipe 70 and circulates again after being cooled.

[0103] In this embodiment, the flow distribution valves 510 include four valves, which are respectively disposed on the branch pipes 502 of the second pipeline 50 .

[0104] The four battery clusters 20 are a first PACK package 211 , a second PACK package 212 , a third PACK package 213 , and a third PACK package 213 ;

[0105] The four flow distribution valves 510 are valve A 511 , valve B 512 , valve C 513 and valve D 514 , and are respectively set corresponding to the first PACK package 211 , the second PACK package 212 , the third PACK package 213 and the third PACK package 213 ; when working normally:

[0106] When valve A 511 is open, valve B 512 , valve C 513 , and valve D 514 are closed;

[0107] When valve B 512 is open, valve A 511 , valve C 513 , and valve D 514 are closed;

[0108] When valve C 513 is open, valve A 511 , valve B 512 , and valve D 514 are closed;

[0109] When valve D 514 is opened, valve A 511 , valve B 512 , and valve C 513 are closed.

[0110] In actual use, the valves in each branch of the second pipeline 50 are opened and closed sequentially in a specific sequence, with each valve open for the same duration to ensure that an equal amount of liquid refrigerant is distributed from each branch to the battery pack 210. The liquid refrigerant undergoes a phase change (vaporization) within the cold plates of the battery packs 20, dissipating heat from the battery cluster 20. In actual operation, the opening and closing cycles of the high-frequency solenoid valves associated with a particular battery pack are primarily determined by the size and number of cold plates within the packs in that battery cluster 20.

[0111] like Figure 3 As shown, in this embodiment, the control logic of the four flow distribution valves 510 when working normally is:

[0112] At time t1, only valve A511 is opened, at time t2, only valve B512 is opened, at time t3, only valve C513 is opened, at time t4, only valve D514 is opened, and so on, the flow distribution of the cluster-level PACK package 210 is finally completed. After one cycle is completed, valve A511 is reopened and the second cycle begins. At each moment, only a stream of fluid flows out of the second liquid storage tank 30, thereby achieving uniform distribution of flow. In addition, the frequency of the high-speed solenoid valve is relatively high, and the uniformity of the fluid in the flow channel after the valve can also be guaranteed to a large extent.

[0113] In other embodiments, the container energy storage device may include more than two battery clusters 20 , and each battery cluster 20 may include more than four PACKs 210 .

[0114] In other embodiments, the second pipeline 50 may also be a plurality of independent single pipes, which sequentially connect the second liquid storage tank 30 and the PACK of the battery cluster 20 .

[0115] like Figure 4 As shown, when the battery management controller determines that the difference between the internal temperature difference of the PACK package 211 and the first value is less than or equal to 1°C, the battery management controller controls the opening of valve A511 to increase by 1 times continuously, while the other flow distribution valves are opened normally.

[0116] like Figure 5 As shown, when the battery management controller determines that the difference between the internal temperature difference of the PACK package 211 and the first value is greater than 1°C and less than the first value (3°C), the battery management controller controls the opening of valve A511 to increase by 2 times in a row, while the remaining flow distribution valves are opened normally.

[0117] Example 2

[0118] The difference between this embodiment and embodiment 1 is that, in this embodiment, the control logic of the thermal management system further includes:

[0119] The battery management controller is used to calculate and determine the internal temperature difference of each PACK package. The internal temperature difference of each PACK package refers to the difference between the highest temperature value and the lowest temperature value among multiple temperature values ​​in each PACK package;

[0120] Its specific judgment logic is the same as the judgment of temperature difference within the cluster.

[0121] The above description is only a preferred embodiment of the present invention and does not limit the scope of patent protection of the present invention. Any equivalent structural transformation made by using the contents of the description and drawings of the present invention, directly or indirectly applied in other related technical fields, is also included in the scope of protection of the present invention.

Claims

1. A thermal management system for a container energy storage device, wherein the container energy storage device comprises a battery cluster, wherein the battery cluster comprises a plurality of PACKs, characterized in that: The thermal management system includes a first liquid storage tank, a second liquid storage tank, a flow distribution valve, a first pipeline and a second pipeline; The first liquid storage tank is used to store refrigerant. The first liquid storage tank and the second liquid storage tank are connected via a first pipeline. The second pipeline includes a main pipe and multiple branch pipes connected to the main pipe. An end of the main pipe away from the branch pipe is connected to the second liquid storage tank. An end of the branch pipe away from the main pipe is used to be connected to the multiple PACKs of the battery cluster respectively. The flow distribution valve is arranged on the branch pipe of the second pipeline; The thermal management system includes a battery management controller; The control logic of the thermal management system includes: The battery management controller collects the NTC temperature measurement information inside the PACK package, numbers and analyzes the collected NTC temperature measurement information; The battery management controller calculates and determines the temperature difference within the cluster: When the temperature difference within the cluster is less than or equal to a first value, the battery management controller controls each flow distribution valve to operate according to a default opening number. The first value ranges from 0°C to 5°C. At this time, the thermal management system operates normally, that is, when the flow distribution valve on one branch pipe is open, the flow distribution valves on the other branches are closed. When the temperature difference within the cluster is greater than the first value, the thermal management system performs response control: the battery management controller determines the battery cluster position, the position of the corresponding high-temperature PACK package within the cluster, and the position of the corresponding flow distribution valve, and recalculates and determines the difference between the temperature difference within the cluster and the first value: When the difference is less than or equal to 1°C, the battery management controller controls to extend the opening time of the flow distribution valve corresponding to the high-temperature PACK package or continuously increase the opening times; When the difference is greater than 1°C and less than the first value, the battery management controller controls to extend the opening time of the flow distribution valve corresponding to the high-temperature PACK package or continuously increase the number of openings, and the extended opening time or the continuously increased number of openings at this time are respectively greater than the extended opening time or the continuously increased number of openings when the difference is less than or equal to 1°C; When the difference is greater than the first value, the battery management controller reports a fault and performs a processing.

2. A thermal management system for a container energy storage device according to claim 1, characterized in that: The battery clusters include a plurality of battery clusters, the second liquid storage tanks include a plurality of second liquid storage tanks, and the plurality of second liquid storage tanks are respectively arranged corresponding to the plurality of battery clusters.

3. The thermal management system of a container energy storage device according to claim 1, characterized in that: It also includes a flow control valve and a pressure sensor, wherein the flow control valve is arranged on the first pipeline and the pressure sensor is arranged inside the second liquid storage tank; The flow control valve is electrically connected to the pressure sensor. When the pressure sensor senses that the internal pressure of the second liquid storage tank is less than the saturated vapor pressure of the refrigerant, the flow control valve opens.

4. A thermal management system for a container energy storage device according to claim 3, characterized in that: The flow control valve is an electrically controlled valve.

5. The thermal management system of a container energy storage device according to claim 1, characterized in that: The flow distribution valve is a solenoid valve.

6. A thermal management system for a container energy storage device according to claim 5, characterized in that: The flow distribution valve is a high-frequency electromagnetic valve.

7. A thermal management system for a container energy storage device according to claim 6, characterized in that: It also includes a pressure buffer device, which is arranged on the branch pipe of the second pipeline and is located between the flow distribution valve and the PACK package.

8. The thermal management system of a container energy storage device according to claim 7, characterized in that: The pressure buffer device is an expansion joint, a shock-absorbing pipe or a post-valve buffer tank.

9. The thermal management system of a container energy storage device according to claim 1, characterized in that: A refrigeration system is also included, wherein an outlet of the refrigeration system is connected to an inlet of the first liquid storage tank.

10. A thermal management system for a container energy storage device according to claim 9, characterized in that: It also includes a third pipeline, one end of which is connected to the outlet of the PACK package, and the other end is connected to the inlet of the refrigeration system.

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