Verification of performance comparison test method for liquid-cooled units

Abstract

This invention discloses a method for verifying the performance comparison test of liquid-cooled units, belonging to the field of new energy technology. The method includes ensuring that a first energy storage container system equipped with a first liquid-cooled unit and a second energy storage container system equipped with a second liquid-cooled unit meet the test conditions; under first, second, and third charge-discharge test conditions, each energy storage container system is tested, and during the tests, each liquid-cooled unit executes the first, second, and third liquid-cooling strategies respectively, obtaining a reactor-level cell temperature dataset and a liquid-cooled unit outlet water temperature dataset; the cooling performance of the liquid-cooled units is compared based on the two datasets to determine the optimal liquid-cooled unit; the charge-discharge rate in the first charge-discharge test condition is lower than that in the third charge-discharge test condition; the highest single-cell temperature required to activate the first liquid-cooling strategy is higher than that of the second liquid-cooling strategy. This scheme can verify the performance of liquid-cooled units and is beneficial for optimizing the configuration of liquid-cooled units in energy storage container systems.

Description

Technical Field

[0001] This invention belongs to the field of new energy technology, and specifically relates to a comparative test method for verifying the performance of liquid-cooled units. Background Technology

[0002] Currently, with the rise of the new energy industry, the development of containerized energy storage systems has become a top priority. Conventional containerized energy storage systems mainly integrate a pack, electrical cabinet, battery management system, thermal management system, and fire suppression system, featuring short integration cycles, high integration levels, and wide applicability. However, with the rapid development and application of the energy storage industry, fires in containerized energy storage systems frequently occur. This is because the energy storage system involves electrical energy conversion and chemical processes during operation, generating a large amount of heat. If this heat cannot be dissipated effectively and promptly, high temperatures accelerate internal chemical reactions within the battery, creating a vicious cycle that leads to thermal runaway and fires. Investigations into the causes of these fires reveal that many originate from battery thermal management failure, and the liquid cooling unit under the thermal management system plays a crucial role in cooling the entire containerized energy storage system and its cells. Therefore, the performance of the liquid cooling unit is a key indicator in the initial stages of containerized energy storage system integration. Determining the appropriate liquid cooling unit is a pressing technical problem that needs to be solved. Summary of the Invention

[0003] To address the aforementioned problems, this invention provides a method for verifying the performance comparison test of a liquid-cooled unit. The liquid-cooled unit is applied to a containerized energy storage system. The liquid-cooled unit includes: a first liquid-cooled unit and a second liquid-cooled unit. The method includes:

[0004] The first containerized energy storage system equipped with the first liquid-cooled unit and the second containerized energy storage system equipped with the second liquid-cooled unit are respectively tested to meet the test conditions. Under the first charge-discharge test condition, the second charge-discharge test condition, and the third charge-discharge test condition, each containerized energy storage system is tested. During the test, the first liquid-cooled unit and the second liquid-cooled unit respectively execute the first liquid-cooling strategy, the second liquid-cooling strategy, and the third liquid-cooling strategy, respectively, to obtain the stack-level cell temperature dataset and the liquid-cooled unit outlet water temperature dataset. Based on the stack-level cell temperature dataset and the liquid-cooled unit outlet water temperature dataset, the cooling performance of the first liquid-cooled unit and the second liquid-cooled unit is compared to determine the optimal liquid-cooled unit. The first charge-discharge test condition is the same as the second charge-discharge test condition, the charge-discharge rate in the first charge-discharge test condition is lower than the charge-discharge rate in the third charge-discharge test condition, the highest cell temperature required to start the first liquid-cooling strategy is higher than that of the second liquid-cooling strategy, and the first liquid-cooling strategy is the same as the third liquid-cooling strategy.

[0005] Optionally, in the method described above, the test conditions are as follows: discharging at a first charge / discharge rate until the voltage of any single cell in the first containerized energy storage system and the second containerized energy storage system reaches a first discharge cutoff voltage; the temperature of any single cell in the first containerized energy storage system and the second containerized energy storage system is within a first temperature range, and the temperature difference between any two single cells is not greater than a second temperature threshold.

[0006] In the method described above, optionally, the first charge-discharge test condition, the second charge-discharge test condition, and the third charge-discharge test condition all include: multiple charge-discharge cycles, each of which sequentially includes: a charging step, a resting step, a discharging step, and the resting step; the charging step is: charging at the charge-discharge rate corresponding to each charge-discharge test condition until the voltage of any single cell in the first containerized energy storage system and the second containerized energy storage system reaches a first charging cutoff voltage and stops; the resting step is: resting for a first duration; the discharging step is: discharging at the charge-discharge rate corresponding to each charge-discharge test condition until the voltage of any single cell in the first containerized energy storage system and the second containerized energy storage system reaches a first discharging cutoff voltage and stops.

[0007] In the method described above, optionally, the charge / discharge rate corresponding to the first charge / discharge test condition is 0.5P, and the charge / discharge rate corresponding to the third charge / discharge test condition is greater than 0.5P and less than 0.58P.

[0008] In the method described above, optionally, the first liquid cooling strategy, the second liquid cooling strategy, and the third liquid cooling strategy all include: a cooling mode, a shutdown mode, and a self-circulation mode. The maximum temperature of a single cell required to start the cooling mode and the shutdown mode of the first liquid cooling strategy is higher than that of the second liquid cooling strategy. The first liquid cooling strategy is the same as the third liquid cooling strategy.

[0009] In the method described above, optionally, the activation condition for the cooling mode of the first liquid cooling strategy is: the highest temperature of a single cell in the first containerized energy storage system and the second containerized energy storage system is not less than a third temperature threshold; the activation condition for the shutdown mode of the first liquid cooling strategy is: the highest temperature of a single cell in the first containerized energy storage system and the second containerized energy storage system is not greater than a fourth temperature threshold and the temperature difference between the single cells is not greater than a fifth temperature threshold; the activation condition for the self-circulation mode of the first liquid cooling strategy is: the highest temperature of a single cell in the first containerized energy storage system and the second containerized energy storage system is not greater than a fifth temperature threshold. The fourth temperature threshold and the temperature difference between individual cells are greater than the fifth temperature threshold; in self-circulation mode, when the temperature difference between individual cells is not greater than the second temperature threshold, the liquid cooling unit shuts down; the starting condition for the cooling mode of the second liquid cooling strategy is: the highest temperature of individual cells in the first containerized energy storage system and the second containerized energy storage system is not less than the sixth temperature threshold, and the sixth temperature threshold is greater than the third temperature threshold; the starting condition for the shutdown mode of the second liquid cooling strategy is: the highest temperature of individual cells in the first containerized energy storage system and the second containerized energy storage system is not greater than the seventh temperature threshold and the temperature difference between individual cells is not greater than the fifth temperature threshold.

[0010] In the method described above, optionally, the third temperature threshold is within the first temperature range, the fourth temperature threshold is less than the third temperature threshold and not within the first temperature range, the fifth temperature threshold is greater than the second temperature threshold, and the seventh temperature threshold is less than the sixth temperature threshold and greater than the third temperature threshold.

[0011] In the method described above, optionally, the first temperature threshold range is 25℃±2℃, the second temperature threshold is 2℃, the third temperature threshold is 25℃, the fourth temperature threshold is 20℃, the fifth temperature threshold is 5℃, the sixth temperature threshold is 32℃, and the seventh temperature threshold is 28℃.

[0012] In the method described above, optionally, the first liquid-cooled unit and the second liquid-cooled unit are of different brands but have the same or similar specifications; the first containerized energy storage system and the second containerized energy storage system are the same containerized energy storage system.

[0013] In the method described above, optionally, the step of comparing the cooling performance of the first liquid cooler and the second liquid cooler based on the reactor cell temperature dataset and the liquid cooler outlet water temperature dataset to determine the optimal liquid cooler includes:

[0014] The reactor-level cell temperature dataset includes: a first set of reactor-level cell temperature data corresponding to the first charge-discharge test condition, a second set of reactor-level cell temperature data corresponding to the second charge-discharge test condition, and a third set of reactor-level cell temperature data corresponding to the third charge-discharge test condition. Each set of reactor-level cell temperature data has: the highest temperature of a single reactor cell and the maximum temperature difference of the reactor-level cells. The liquid cooler unit outlet water temperature dataset includes: a first set of liquid cooler unit outlet water temperatures corresponding to the first charge-discharge test condition, a second set of liquid cooler unit outlet water temperatures corresponding to the second charge-discharge test condition, and a third set of liquid cooler unit outlet water temperatures corresponding to the third charge-discharge test condition. Under the first charge-discharge test condition, the second charge-discharge test condition, and the third charge-discharge test condition, the optimal liquid cooler unit among the first liquid cooler unit and the second liquid cooler unit has the lowest highest temperature of a single reactor cell, the maximum temperature difference of the reactor-level cells, and the lowest liquid cooler unit outlet water temperature.

[0015] The beneficial effects of the technical solution provided by the embodiments of the present invention are as follows:

[0016] By ensuring that the first containerized energy storage system equipped with the first liquid-cooled unit and the second containerized energy storage system equipped with the second liquid-cooled unit meet the test conditions respectively, and by testing each containerized energy storage system under the first charge-discharge test condition, the second charge-discharge test condition, and the third charge-discharge test condition respectively, and by executing the first liquid-cooling strategy, the second liquid-cooling strategy, and the third liquid-cooling strategy respectively for the first and second liquid-cooled units respectively, the reactor-level cell temperature dataset and the liquid-cooled unit outlet water temperature dataset are obtained; based on the reactor-level cell temperature dataset and the liquid-cooled unit... The water outlet temperature dataset is used to compare the cooling performance of the first and second liquid-cooled units to determine the optimal liquid-cooled unit. The first charge-discharge test condition is the same as the second charge-discharge test condition, but the charge-discharge rate in the first charge-discharge test condition is lower than that in the third charge-discharge test condition. The highest temperature of the individual cells required to start the first liquid-cooling strategy is higher than that of the second liquid-cooling strategy. The first liquid-cooling strategy is the same as the third liquid-cooling strategy. This can verify the performance of the two liquid-cooled units, determine the optimal liquid-cooled unit, and facilitate the optimization of the configuration of liquid-cooled units in the energy storage container system. Attached Figure Description

[0017] Figure 1 A flowchart illustrating a performance comparison test method for verifying liquid-cooled units provided in an embodiment of the present invention;

[0018] Figure 2 A schematic diagram of the highest temperature of a single cell in the first group of cell temperature data corresponding to the first liquid cooling unit, provided in an embodiment of the present invention;

[0019] Figure 3A schematic diagram of the highest temperature of a single cell in the first group of cell temperature data corresponding to the second liquid cooling unit, provided in an embodiment of the present invention;

[0020] Figure 4 A schematic diagram of the highest temperature of a single cell in the second set of cell temperature data corresponding to the first liquid cooling unit, provided in an embodiment of the present invention;

[0021] Figure 5 A schematic diagram of the highest temperature of a single cell in the second set of cell temperature data corresponding to the second liquid cooling unit, provided in an embodiment of the present invention;

[0022] Figure 6 A schematic diagram of the highest temperature of a single cell in the third group of cell temperature data corresponding to the first liquid cooling unit, provided in an embodiment of the present invention;

[0023] Figure 7 A schematic diagram of the highest temperature of a single cell in the third group of cell temperature data corresponding to the second liquid cooling unit, provided in an embodiment of the present invention;

[0024] Figure 8 A schematic diagram of the maximum temperature difference of the stack-level cells in the first set of stack-level cell temperature data corresponding to the first liquid cooling unit and the second liquid cooling unit, provided for an embodiment of the present invention;

[0025] Figure 9 A schematic diagram of the maximum temperature difference of the stack-level cells in the second set of stack-level cell temperature data corresponding to the first liquid cooling unit and the second liquid cooling unit, provided for an embodiment of the present invention;

[0026] Figure 10 A schematic diagram of the maximum temperature difference of the stack-level cells in the third set of stack-level cell temperature data corresponding to the first liquid cooling unit and the second liquid cooling unit, provided for an embodiment of the present invention;

[0027] Figure 11 This is a schematic diagram of the outlet water temperature data of a first group of liquid coolers corresponding to a first liquid cooler unit, provided in an embodiment of the present invention.

[0028] Figure 12 This is a schematic diagram of the outlet water temperature data of the first group of liquid chillers corresponding to the second liquid chiller unit, provided in an embodiment of the present invention.

[0029] Figure 13 This is a schematic diagram of the outlet water temperature data of a second group of liquid chillers corresponding to a first liquid chiller unit, provided in an embodiment of the present invention.

[0030] Figure 14 A schematic diagram of the outlet water temperature data of the second group of liquid chillers corresponding to the second liquid chiller unit provided in an embodiment of the present invention;

[0031] Figure 15 A schematic diagram of the outlet water temperature data of a third group of liquid coolers corresponding to the first liquid cooler unit provided in an embodiment of the present invention;

[0032] Figure 16 This is a schematic diagram of the outlet water temperature data of a third group of liquid chillers corresponding to the second liquid chiller unit, provided as an embodiment of the present invention. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] The terminology used in the embodiments of this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention. The singular forms “a,” “the,” and “the” as used in the embodiments of this invention and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0035] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0036] Depending on the context, the word "if" as used here can be interpreted as "when," "when," "in response to determination," or "in response to detection." Similarly, depending on the context, the phrase "if determination" or "if monitoring (the stated condition or event)" can be interpreted as "when determination," "in response to determination," "when monitoring (the stated condition or event)," or "in response to monitoring (the stated condition or event)."

[0037] It should be noted that the terms "first" and "second" used in the embodiments of the present invention do not have limitations in terms of size, order, or quantity, but are only used to distinguish them by name. For example, "first preset voltage threshold" and "second preset voltage threshold" are used to distinguish two different preset voltage thresholds, and "first preset time", "second preset time" and "third preset time" are used to distinguish three different preset time values.

[0038] See Figure 1 This invention provides a method for verifying the performance comparison test of a liquid-cooled chiller unit. The liquid-cooled chiller unit is applied to a containerized energy storage system and includes a first liquid-cooled chiller unit and a second liquid-cooled chiller unit. The first and second liquid-cooled chiller units are of different brands but have the same or similar specifications. When the specifications are similar, that is, the difference in specification parameters is within a preset requirement range, the specification parameters can be cooling capacity, or in other embodiments, dimensions. The brand corresponding to the first liquid-cooled chiller unit can be referred to as Brand 1, and the brand corresponding to the second liquid-cooled chiller unit can be referred to as Brand 2.

[0039] The method includes the following steps:

[0040] Step 101: Ensure that the first containerized energy storage system equipped with the first liquid-cooled unit and the second containerized energy storage system equipped with the second liquid-cooled unit meet the test conditions respectively.

[0041] When applying this method, a single containerized energy storage system can be deployed, where the first and second liquid-cooled units share the same system. After the containerized energy storage system with the first liquid-cooled unit is tested, it is disassembled, the second liquid-cooled unit is installed, and then the system is tested again. To better distinguish and describe this method, the containerized energy storage system with the first liquid-cooled unit is referred to as the first containerized energy storage system or the first energy storage container system; the containerized energy storage system with the second liquid-cooled unit is referred to as the second containerized energy storage system or the second energy storage container system. The purpose of this step is to ensure that each containerized energy storage system meets the test conditions, allowing testing to begin. In other embodiments, two identical containerized energy storage systems can be deployed, one with an independently configured first liquid-cooled unit and the other with an independently configured second liquid-cooled unit. It should be noted that, to improve the consistency of the tests, it is preferable to deploy only one containerized energy storage system. The configuration of the containerized energy storage system should be such that it can complete the test method described herein. Its configuration can be the same as that of a conventional containerized energy storage system, such as including a fire protection system. In other embodiments, the fire protection system may not be included. This embodiment does not limit this.

[0042] First, discharge operations are performed on each containerized energy storage system. Specifically, discharge is carried out at a first charge / discharge rate until the voltage of any single cell in the first containerized energy storage system reaches the first discharge cutoff voltage; discharge is then carried out at the same first charge / discharge rate until the voltage of any single cell in the second containerized energy storage system reaches the first discharge cutoff voltage. The first charge / discharge rate is preferably 0.5P, and the first discharge cutoff voltage is preferably 2.5V. This embodiment does not limit these values, and they can be adjusted according to specific requirements.

[0043] Then, a temperature equalization operation is performed to ensure that the temperature of any single cell in each containerized energy storage system is within a first temperature range, and the temperature difference between any two cells does not exceed a second temperature threshold. Specifically, in the first containerized energy storage system, the temperature of any single cell is within the first temperature range, and the temperature difference between any two cells is not greater than the second temperature threshold; similarly, in the second containerized energy storage system, the temperature of any single cell is within the first temperature range, and the temperature difference between any two cells is not greater than the second temperature threshold. The temperature difference between any two cells refers to the temperature difference between any two cells in the containerized energy storage system. The first temperature range is preferably 25℃ ± 2℃, and the second temperature threshold is preferably 2℃. This embodiment does not limit these values, and they can be adjusted according to specific requirements. The temperature equalization operation can be achieved by manually controlling the liquid cooling unit. Unlike the first, second, and third liquid cooling strategies described below, which are achieved by automatically controlling the liquid cooling unit, this operation is performed manually.

[0044] Step 102: Under the first charge-discharge test condition, the second charge-discharge test condition, and the third charge-discharge test condition, each containerized energy storage system is tested. During the test, the first liquid-cooled unit and the second liquid-cooled unit respectively execute the first liquid-cooling strategy, the second liquid-cooling strategy, and the third liquid-cooling strategy to obtain the stack-level cell temperature dataset and the liquid-cooled unit outlet water temperature dataset.

[0045] Three charge-discharge test conditions were set up: the first charge-discharge test condition, the second charge-discharge test condition, and the third charge-discharge test condition. Each charge-discharge test condition includes multiple charge-discharge cycles, which can be 3-5 times, such as 3, 4, or 5 times. In other embodiments, other numbers may also be used, but this embodiment does not limit this. Each charge-discharge cycle includes, in sequence: a charging step, a resting step, a discharging step, and a resting step.

[0046] Specifically: Charging step: Charging at the charge / discharge rate corresponding to the charge / discharge test conditions until the voltage of any single cell in the first containerized energy storage system and the second containerized energy storage system reaches the first charging cutoff voltage. The first charging cutoff voltage is preferably 3.65V, but this embodiment does not specifically limit it and other values ​​are also possible. Resting step: Resting for a first time, preferably 1 hour. Discharging step: Discharging at the charge / discharge rate corresponding to the charge / discharge test conditions until the voltage of any single cell in the first containerized energy storage system and the second containerized energy storage system reaches the first discharging cutoff voltage.

[0047] The first charge / discharge test condition is the same as the second charge / discharge test condition, but the charge / discharge rate in the first charge / discharge test condition is lower than the charge / discharge rate in the third charge / discharge test condition. Specifically, when the charge / discharge test condition is the first or second charge / discharge test condition, the charge / discharge rate corresponding to both conditions is the same: the first charge / discharge rate. When the charge / discharge test condition is the third charge / discharge test condition, the charge / discharge rate corresponding to this condition is higher than the first charge / discharge rate, and its value can be greater than 0.5P and less than 0.58P, such as 0.51P, 0.52P, 0.53P, 0.54P, 0.55P, 0.56P, and 0.57P.

[0048] Three liquid cooling strategies were set up: a first liquid cooling strategy, a second liquid cooling strategy, and a third liquid cooling strategy, corresponding to three charge-discharge test conditions. Specifically, the first charge-discharge test condition corresponds to the first liquid cooling strategy; under this condition, each containerized energy storage system was tested, and the first and second liquid cooling units respectively implemented the first liquid cooling strategy. The second charge-discharge test condition corresponds to the second liquid cooling strategy; under this condition, each containerized energy storage system was tested, and the first and second liquid cooling units respectively implemented the second liquid cooling strategy. The third charge-discharge test condition corresponds to the third liquid cooling strategy; under this condition, each containerized energy storage system was tested, and the first and second liquid cooling units respectively implemented the third liquid cooling strategy. The first liquid cooling strategy requires a higher maximum cell temperature than the second liquid cooling strategy to activate. Specifically, the first liquid cooling strategy activates when the highest temperature of any single cell in the containerized energy storage system reaches a certain value. The second liquid cooling strategy activates when the highest temperature of any single cell in the containerized energy storage system reaches another certain value. The highest temperature of the single cell at the activation of the first liquid cooling strategy is higher than that at the activation of the second liquid cooling strategy. The first liquid cooling strategy is the same as the third liquid cooling strategy. It should be noted that when the three liquid cooling strategies are executed separately, the outlet temperature of the liquid cooling unit (i.e., the target temperature or cooling setpoint temperature) needs to be set, preferably to 18°C.

[0049] Each of the three liquid cooling strategies includes: cooling mode, shutdown mode, and self-circulation mode. The highest cell temperature required to start the cooling and shutdown modes of the first liquid cooling strategy is higher than that of the second liquid cooling strategy. Cooling mode refers to the liquid cooling unit being turned on and in cooling operation; shutdown mode refers to the liquid cooling unit being turned on but not in operation; self-circulation mode refers to the liquid cooling unit entering a self-circulation state of the coolant in the liquid cooling pipeline, i.e., neither heating nor cooling, and not considered a shutdown state.

[0050] The activation conditions for the cooling mode of the first liquid cooling strategy are as follows: When the highest temperature of a single cell in the containerized energy storage system is not lower than the third temperature threshold, the cooling mode is activated, i.e., the liquid cooling unit starts cooling. The third temperature threshold falls within the first temperature range, preferably 25℃. The activation conditions for the shutdown mode of the first liquid cooling strategy are as follows: When the highest temperature of a single cell in the containerized energy storage system is not higher than the fourth temperature threshold and the temperature difference between cells is not higher than the fifth temperature threshold, the shutdown mode is activated, i.e., the liquid cooling unit shuts down. The fourth temperature threshold is lower than the third temperature threshold, preferably 20℃; the fifth temperature threshold is higher than the second temperature threshold, preferably 5℃. The activation conditions for the self-circulation mode of the first liquid cooling strategy are as follows: When the highest temperature of a single cell in the containerized energy storage system is not higher than the fourth temperature threshold and the temperature difference between cells is greater than the fifth temperature threshold, the self-circulation mode is activated, i.e., the liquid cooling unit starts self-circulation. In this mode, the liquid cooling unit shuts down when the temperature difference between cells is not greater than the second temperature threshold. In other words, preferably, under the first liquid cooling strategy, when the highest temperature is ≥25℃, cooling is turned on and the outlet water temperature (or outlet temperature) of the liquid cooling unit is 18℃; when the highest temperature is ≤20℃ and the temperature difference is ≤5℃, the liquid cooling unit is shut down; when the highest temperature is ≤20℃ and the temperature difference is >5℃, cooling is stopped and self-circulation is turned on, and the liquid cooling unit is shut down when the temperature difference is ≤2℃.

[0051] The activation conditions for the cooling mode of the second liquid cooling strategy are as follows: When the highest temperature of a single cell in the containerized energy storage system is not less than the sixth temperature threshold, the cooling mode is activated, i.e., the liquid cooling unit starts cooling. The sixth temperature threshold is greater than the third temperature threshold. Preferably, the sixth temperature threshold is greater than the third temperature threshold but not within the first temperature range, preferably 32℃. The activation conditions for the shutdown mode of the second liquid cooling strategy are as follows: When the highest temperature of a single cell in the containerized energy storage system is not greater than the seventh temperature threshold and the temperature difference between the cells is not greater than the fifth temperature threshold, the shutdown mode is activated, i.e., the liquid cooling unit shuts down. The seventh temperature threshold is less than the sixth temperature threshold but greater than the third temperature threshold, preferably 28℃. The activation conditions for the self-circulation mode of the second liquid cooling strategy are the same as those for the self-circulation mode of the first liquid cooling strategy. In other words, preferably, under the second liquid cooling strategy, when the highest temperature is ≥32℃, the cooling is turned on and the water temperature at the outlet of the liquid cooling unit is 18℃; when the highest temperature is ≤28℃ and the temperature difference is ≤5℃, the liquid cooling unit is shut down; when the highest temperature is ≤20℃ and the temperature difference is >5℃, the cooling is stopped and the self-circulation is turned on, and the liquid cooling unit is shut down when the temperature difference is ≤2℃.

[0052] When this method is applied, the power consumption of the first liquid cooling unit and the second liquid cooling unit during the test can also be recorded separately. The first charge-discharge test condition can be called: the normal charge-discharge condition, the second charge-discharge test condition can be called: the condition of raising the cell temperature, and the third charge-discharge test condition can be called: the condition of raising the charge-discharge rate.

[0053] Under the first charge-discharge test condition and the first liquid cooling strategy, the first and second liquid cooling units were tested separately, obtaining the first set of reactor-level cell temperature data and the first set of liquid cooling unit outlet water temperature data. Under the second test charge-discharge test condition and the second liquid cooling strategy, the first and second liquid cooling units were tested separately, obtaining the second set of reactor-level cell temperature data and the second set of liquid cooling unit outlet water temperature data. Under the third test charge-discharge test condition and the third liquid cooling strategy, the first and second liquid cooling units were tested separately, obtaining the third set of reactor-level cell temperature data and the third set of liquid cooling unit outlet water temperature data. The first, second, and third sets of reactor-level cell temperature data were collected to form a reactor-level cell temperature dataset; the first, second, and third sets of liquid cooling unit outlet water temperature data were collected to form a liquid cooling unit outlet water temperature dataset. It should be noted that: Stack-level cell temperature data refers to the temperature data of all individual cells in a containerized energy storage system, including: the highest temperature of each individual cell and the maximum temperature difference among all cells in the stack-level system. The highest temperature of each individual cell refers to the highest temperature among all individual cells in the containerized energy storage system, encompassing both the highest temperature during charging and discharging. The maximum temperature difference among all cells in the stack-level system refers to the maximum temperature difference between any two individual cells in the containerized energy storage system during charging and discharging. Stack-level cell temperature data can be obtained through measurements by the BMS (Battery Management System) of the containerized energy storage system. Liquid cooler unit outlet water temperature data refers to the average temperature of the water at the liquid cooler unit outlet, i.e., the average outlet water temperature. The outlet water temperature data of the liquid chiller unit can be obtained by measuring the liquid chiller unit itself.

[0054] Step 103: Based on the reactor-level cell temperature dataset and the liquid cooler outlet water temperature dataset, compare the cooling performance of the first liquid cooler and the second liquid cooler to determine the optimal liquid cooler.

[0055] Among the first and second liquid-cooled units, the optimal liquid-cooled unit has the lowest maximum reactor cell temperature, maximum reactor-level cell temperature difference, and liquid-cooled unit outlet water temperature. That is, under the first, second, and third liquid-cooling strategies, the optimal liquid-cooled unit's maximum reactor cell temperature, maximum reactor-level cell temperature difference, and liquid-cooled unit outlet water temperature are all no higher than those of the other liquid-cooled unit.

[0056] Specifically, by executing step 102, the highest temperature of a single cell in the first set of cell temperature data can be obtained:

[0057] Brand 1: The maximum temperature of a single stack cell during charging is 35℃, and the maximum temperature of a single stack cell during discharging is 35℃. Figure 2 As shown by the yellow line; Brand 2: The highest temperature of a single stack cell during charging is 34℃, and the highest temperature of a single stack cell during discharging is 34℃, as shown in the yellow line; Figure 3 As shown by the red line. Conclusion: Brand 2 has better cooling performance than Brand 1.

[0058] The highest temperature of a single cell in the second set of cell temperature data can also be obtained:

[0059] Brand 1: The highest temperature of a single stack cell during charging is 38℃, and the highest temperature of a single stack cell during discharging is 37℃. Figure 4 As shown by the red line; Brand 2: The highest temperature of a single stack cell during charging is 37℃, and the highest temperature of a single stack cell during discharging is 36℃, as shown in the red line; Figure 5 As shown by the red line in the figure; Conclusion: Brand 2 has better cooling performance than Brand 1.

[0060] We can also obtain: the highest temperature of a single cell in the third set of cell temperature data:

[0061] Brand 1: The highest temperature of a single stack cell during charging is 37℃, and the highest temperature of a single stack cell during discharging is 38℃. Figure 6 As shown by the red line; Brand 2: The highest temperature of a single stack cell during charging is 36℃, and the highest temperature of a single stack cell during discharging is 37℃, as shown in the red line; Figure 7 As shown by the red line in the figure; Conclusion: Brand 2 has better cooling performance than Brand 1.

[0062] We can also obtain: the maximum temperature difference between the stack-level cells in the first set of stack-level cell temperature data:

[0063] Brand 1: The maximum temperature difference between the stack-level cells during charging and discharging is 6℃, such as... Figure 8 As shown by the blue line; Brand 2: The maximum temperature difference between the stack-level cells during charging and discharging is 5℃, as shown by the blue line; Figure 8 As shown by the orange line in the figure; Conclusion: Brand 2 has better cooling performance than Brand 1.

[0064] We can also obtain: the maximum temperature difference between the stack-level cells in the second set of stack-level cell temperature data:

[0065] Brand 1: The maximum temperature difference between the stack-level cells during charging and discharging is 6℃, such as... Figure 9 As shown by the blue line; Brand 2: The maximum temperature difference between the stack-level cells during charging and discharging is 5℃, as shown by the blue line; Figure 9 As shown by the orange line in the figure; Conclusion: Brand 2 has better cooling performance than Brand 1.

[0066] We can also obtain: the maximum temperature difference between the stack-level cells in the third set of stack-level cell temperature data:

[0067] Brand 1: The maximum temperature difference between the stack-level cells during charging and discharging is 6℃, such as... Figure 10 As shown by the blue line; Brand 2: The maximum temperature difference between the stack-level cells during charging and discharging is 5℃, as shown by the blue line; Figure 10 As shown by the orange line in the figure; Conclusion: Brand 2 has better cooling performance than Brand 1.

[0068] We can also obtain: the outlet water temperature of the first group of liquid chillers:

[0069] Brand 1: The outlet water temperature data shows that the liquid-cooled unit's outlet water temperature remains below 18℃ during both the discharge and charging processes, with an average outlet water temperature of 20℃. Figure 11 The orange line in the image represents the average outlet water temperature; Brand 2: The outlet water temperature data shows that the liquid-cooled unit's outlet water temperature remains below 18℃ during both the discharge and charging processes, with an average outlet water temperature of 17.36℃. Figure 12 The orange line in the figure represents the average outlet water temperature; Conclusion: Brand 2 has better cooling performance than Brand 1.

[0070] We can also obtain: the outlet water temperature of the second group of liquid chillers:

[0071] Brand 1: The outlet water temperature data shows that the liquid-cooled unit maintains an outlet water temperature of ≥18℃ during both the discharge and charging processes, with an average outlet water temperature of 22.4℃. Figure 13 The orange line in the image represents the average outlet water temperature; Brand 2: The outlet water temperature data shows that the liquid-cooled unit maintains an outlet water temperature of ≥18℃ during both the discharge and charging processes, with an average outlet water temperature of 19.2℃. Figure 14 The orange line in the figure represents the average outlet water temperature; Conclusion: Brand 2 has better cooling performance than Brand 1.

[0072] We can also obtain: the outlet water temperature of the third group of liquid chillers:

[0073] Brand 1: The outlet water temperature data shows that the liquid-cooled unit maintains an outlet water temperature of ≥18℃ during both the discharge and charging processes, with an average outlet water temperature of 20℃. Figure 15The gray line in the image represents the average outlet water temperature; Brand 2: The outlet water temperature data shows that the liquid-cooled unit maintains an outlet water temperature of ≥18℃ during both the discharge and charging processes, with an average outlet water temperature of 18.2℃. Figure 16 The orange line in the figure represents the average outlet water temperature; Conclusion: Brand 2 has better cooling performance than Brand 1.

[0074] By conducting comparative tests, test data was obtained. Specifically, the tests compared three aspects: the highest temperature of the reactor unit, the maximum temperature difference between the reactor-level cells, and the outlet water temperature of the liquid cooler unit. This determined which liquid cooler unit had the best performance, i.e., the optimal liquid cooler unit. A lower highest temperature of the reactor unit indicates higher performance; a smaller maximum temperature difference between the reactor-level cells indicates higher performance; and a lower outlet water temperature indicates higher performance. In other embodiments, an additional aspect can be added: the lowest temperature of the reactor unit. Accordingly, a lower lowest temperature of the reactor unit indicates higher performance of the liquid cooler unit.

[0075] As is known from common technical knowledge, this invention can be implemented through other embodiments that do not depart from its spirit or essential characteristics. Therefore, the disclosed embodiments described above are merely illustrative in all respects and are not the only ones. All modifications within the scope of this invention or its equivalents are included in this invention.

Claims

1. A method for verifying the performance comparison test of a liquid-cooled unit, wherein the liquid-cooled unit is applied to a containerized energy storage system, characterized in that, The liquid cooling unit includes: a first liquid cooling unit and a second liquid cooling unit, and the method includes: The first containerized energy storage system equipped with the first liquid-cooled unit and the second containerized energy storage system equipped with the second liquid-cooled unit shall respectively meet the test conditions; Under the first charge-discharge test condition, the second charge-discharge test condition, and the third charge-discharge test condition, each containerized energy storage system was tested. During the test, the first liquid-cooled unit and the second liquid-cooled unit respectively executed the first liquid-cooling strategy, the second liquid-cooling strategy, and the third liquid-cooling strategy, respectively, to obtain the stack-level cell temperature dataset and the liquid-cooled unit outlet water temperature dataset. Based on the reactor cell temperature dataset and the liquid cooler outlet water temperature dataset, the cooling performance of the first liquid cooler and the second liquid cooler is compared to determine the optimal liquid cooler. Wherein, the first charge-discharge test condition is the same as the second charge-discharge test condition, and the charge-discharge rate in the first charge-discharge test condition is less than the charge-discharge rate in the third charge-discharge test condition; The highest temperature of a single cell required to activate the first liquid cooling strategy is higher than that of the second liquid cooling strategy. The first liquid cooling strategy is the same as the third liquid cooling strategy.

2. The method according to claim 1, characterized in that, The test conditions are as follows: discharge at the first charge-discharge rate until the voltage of any single cell in the first containerized energy storage system and the second containerized energy storage system reaches the first discharge cutoff voltage and then stops. In the first containerized energy storage system and the second containerized energy storage system, the temperature of any single cell is within a first temperature range, and the temperature difference between any two single cells is not greater than a second temperature threshold.

3. The method according to claim 1, characterized in that, The first charge-discharge test condition, the second charge-discharge test condition, and the third charge-discharge test condition all include: multiple charge-discharge cycle processes, and any one of the charge-discharge cycle processes includes, in sequence: a charging step, a resting step, a discharging step, and the resting step; The charging process is as follows: charging at the charge / discharge rate corresponding to each charge / discharge test condition until the voltage of any single cell in the first containerized energy storage system and the second containerized energy storage system reaches the first charging cutoff voltage and then stopping. The settling step is: settling for a first duration; The discharge step is as follows: discharge at the charge / discharge rate corresponding to each charge / discharge test condition until the voltage of any single cell in the first containerized energy storage system and the second containerized energy storage system reaches the first discharge cutoff voltage and then stops.

4. The method according to claim 3, characterized in that, The charge / discharge rate corresponding to the first charge / discharge test condition is 0.5P, and the charge / discharge rate corresponding to the third charge / discharge test condition is greater than 0.5P and less than 0.58P.

5. The method according to claim 2, characterized in that, The first liquid cooling strategy, the second liquid cooling strategy, and the third liquid cooling strategy all include: a cooling mode, a shutdown mode, and a self-circulation mode. The maximum temperature of a single cell required to start the cooling mode and the shutdown mode of the first liquid cooling strategy is higher than that of the second liquid cooling strategy. The first liquid cooling strategy is the same as the third liquid cooling strategy.

6. The method according to claim 5, characterized in that, The activation condition for the cooling mode of the first liquid cooling strategy is: the highest temperature of a single cell in the first containerized energy storage system and the second containerized energy storage system is not less than a third temperature threshold. The start-up conditions for the shutdown mode of the first liquid cooling strategy are: the highest temperature of a single cell in the first containerized energy storage system and the second containerized energy storage system is not greater than the fourth temperature threshold and the temperature difference between the single cells is not greater than the fifth temperature threshold. The activation conditions for the self-circulation mode of the first liquid cooling strategy are: the highest temperature of a single cell in the first containerized energy storage system and the second containerized energy storage system is not greater than the fourth temperature threshold and the temperature difference between the single cells is greater than the fifth temperature threshold; in the self-circulation mode, when the temperature difference between the single cells is not greater than the second temperature threshold, the liquid cooling unit is shut down. The activation condition for the cooling mode of the second liquid cooling strategy is: the highest temperature of a single cell in the first containerized energy storage system and the second containerized energy storage system is not less than the sixth temperature threshold, and the sixth temperature threshold is greater than the third temperature threshold. The start-up conditions for the shutdown mode of the second liquid cooling strategy are: the highest temperature of a single cell in the first containerized energy storage system and the second containerized energy storage system is not greater than the seventh temperature threshold and the temperature difference between the single cells is not greater than the fifth temperature threshold.

7. The method according to claim 6, characterized in that, The third temperature threshold is within the first temperature range, the fourth temperature threshold is less than the third temperature threshold and is not within the first temperature range, the fifth temperature threshold is greater than the second temperature threshold, and the seventh temperature threshold is less than the sixth temperature threshold and greater than the third temperature threshold.

8. The method according to claim 7, characterized in that, The first temperature threshold range is 25℃±2℃, the second temperature threshold is 2℃, the third temperature threshold is 25℃, the fourth temperature threshold is 20℃, the fifth temperature threshold is 5℃, the sixth temperature threshold is 32℃, and the seventh temperature threshold is 28℃.

9. The method according to claim 1, characterized in that, The first liquid cooling unit and the second liquid cooling unit are of different brands but have the same or similar specifications; The first containerized energy storage system and the second containerized energy storage system are the same containerized energy storage system.

10. The method according to claim 1, characterized in that, The step of comparing the cooling performance of the first liquid cooler and the second liquid cooler based on the reactor cell temperature dataset and the liquid cooler outlet water temperature dataset to determine the optimal liquid cooler includes: The stack-level cell temperature dataset includes: a first set of stack-level cell temperature data corresponding to the first charge-discharge test condition, a second set of stack-level cell temperature data corresponding to the second charge-discharge test condition, and a third set of stack-level cell temperature data corresponding to the third charge-discharge test condition. Each set of stack-level cell temperature data has: the highest temperature of a single stack cell and the maximum temperature difference of the stack-level cells. The liquid chiller outlet water temperature dataset includes: a first set of liquid chiller outlet water temperatures corresponding to the first charge-discharge test condition, a second set of liquid chiller outlet water temperatures corresponding to the second charge-discharge test condition, and a third set of liquid chiller outlet water temperatures corresponding to the third charge-discharge test condition. Under the first charge-discharge test condition, the second charge-discharge test condition, and the third charge-discharge test condition, the optimal liquid cooler unit among the first liquid cooler unit and the second liquid cooler unit has the lowest maximum temperature of the individual reactor cell, the maximum temperature difference of the reactor-level cells, and the lowest outlet water temperature of the liquid cooler unit.

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