Immersed energy storage temperature control method and energy storage cabinet

Abstract

The invention relates to the field of energy storage, and particularly discloses an immersed energy storage temperature control method and an energy storage cabinet, and the method comprises the steps: detecting the cell temperature of an upper-layer battery pack and a lower-layer battery pack in real time; when the cell temperatures of all the battery packs are smaller than the basic temperature threshold value, if the difference between the cell temperatures of the two adjacent layers of battery packs exceeds a first temperature threshold value, a first temperature control strategy is adopted for temperature regulation and control; and if the temperature difference of the battery cells of the top-layer battery pack and the bottom-layer battery pack exceeds a second temperature threshold value, carrying out temperature regulation and control by adopting a second temperature control strategy. Temperature control is carried out according to the temperature difference between the battery packs, energy is saved, the temperature adjusting effect is improved, temperature equalization is achieved, and the battery efficiency and safety are improved.

Description

Technical Field

[0001] The present invention relates to the field of energy storage, and in particular to an immersion energy storage temperature control method and an energy storage cabinet. Background Art

[0002] In energy storage systems, battery packs are the core components of energy storage. Their performance stability and safety are directly related to the operating efficiency and reliability of the entire energy storage system. However, in the actual operation of battery packs, due to the complexity of the chemical reactions inside the battery and the influence of external environmental factors, the temperature of the battery cells often varies unevenly, that is, the temperature of the battery packs at different locations varies greatly. This temperature difference not only affects the performance and life of the battery, but may also cause safety issues such as thermal runaway.

[0003] Traditional energy storage system temperature control methods mostly use air cooling or natural heat dissipation, but these methods are often difficult to effectively achieve uniform temperature control when facing large-scale, high-density battery pack arrays. In immersion energy storage systems, battery packs are directly immersed in insulating coolant, which improves heat dissipation efficiency, but traditional liquid cooling temperature control strategies are relatively simple, generally only detecting and controlling the temperature of each individual battery pack, resulting in unsatisfactory temperature control effects and difficulty in ensuring temperature balance, which in turn affects battery efficiency and safety. Summary of the invention

[0004] To solve the above problems, the present invention provides an immersion energy storage temperature control method and an energy storage cabinet, which perform temperature control according to the temperature difference between battery packs, save energy, improve temperature regulation effect, achieve temperature balance, and improve battery efficiency and safety.

[0005] In a first aspect, the technical solution of the present invention provides an immersion energy storage temperature control method, comprising the following steps: Real-time detection of the battery cell temperature of each layer of the upper and lower battery packs; Determine whether the temperature of the battery cell of the battery pack exceeds the basic temperature threshold; If present, increase the liquid cooling flow of the battery pack whose cell temperature exceeds the basic temperature threshold until its cell temperature is lower than the basic temperature threshold; If not present, detect the difference between the cell temperatures of two adjacent battery packs, and the difference between the cell temperatures of the top and bottom battery packs; If the temperature difference between the cells of two adjacent battery packs exceeds a first temperature threshold, the first temperature control strategy is used for temperature control; if the temperature difference between the cells of the top and bottom battery packs exceeds a second temperature threshold, the second temperature control strategy is used for temperature control.

[0006] In an optional implementation, the first temperature control strategy is used to control the temperature, specifically including: Detect the difference level of the temperature difference between the cells of two adjacent battery packs; Retrieving a mapping relationship between a difference level and a flow adjustment step length, which is recorded as a first mapping relationship; According to the retrieved first mapping relationship, a flow adjustment step length adapted to the difference level is obtained; Increase the liquid cooling flow rate of the layer with higher cell temperature according to the flow adjustment step length, and reduce the liquid cooling flow rate of the layer with lower cell temperature according to the flow adjustment step length; After adjusting the liquid cooling flow for a preset time, if the difference in battery cell temperature between two adjacent battery pack layers is still not lower than the first temperature threshold, the liquid cooling flow of the layer with higher battery cell temperature will continue to be increased according to the flow adjustment step. At the same time, the liquid cooling flow of the layer with lower battery cell temperature will be reduced according to the flow adjustment step, and the radiator power of the liquid cooling component will be increased until the difference in battery cell temperature is lower than the first temperature threshold.

[0007] In an optional implementation, the second temperature control strategy is used to control the temperature, specifically including: Detect the difference level between the top and bottom battery pack cell temperatures; Retrieving a mapping relationship between a difference level and a flow adjustment step length, which is recorded as a second mapping relationship; According to the retrieved second mapping relationship, a flow adjustment step length adapted to the difference level is obtained; Divide the battery packs into upper battery packs and lower battery packs according to the labels; If the cell temperature of the top battery pack is greater than that of the bottom battery pack, the liquid cooling flow rate of the upper battery pack is increased according to the flow adjustment step length, and the liquid cooling flow rate of the lower battery pack is reduced according to the flow adjustment step length; If the cell temperature of the top battery pack is lower than that of the bottom battery pack, the liquid cooling flow rate of the upper battery pack is reduced according to the flow adjustment step length, and the liquid cooling flow rate of the lower battery pack is increased according to the flow adjustment step length; After adjusting the liquid cooling flow for a preset time, if the difference in battery cell temperature between the top and bottom battery packs is still not lower than the second temperature threshold, continue to adjust the flow according to the flow adjustment step and increase the radiator power of the liquid cooling component until the difference in battery cell temperature is lower than the first temperature threshold.

[0008] In a second aspect, the technical solution of the present invention provides an immersion energy storage cabinet, comprising a cabinet body and a cabinet door, wherein a first space, a second space and a third space are sequentially arranged in the cabinet body from top to bottom; The first space is provided with a multi-layer battery pack arranged up and down; the second space is provided with an energy storage converter and an energy storage control system; the third space is provided with a liquid cooling component; Among them, the energy storage control system executes any of the above-mentioned immersion energy storage temperature control methods.

[0009] In an optional embodiment, the energy storage control system includes a battery management subsystem and an energy management subsystem; wherein the battery management subsystem executes any of the above-mentioned immersion energy storage temperature control methods.

[0010] In an optional embodiment, a dehumidifier is also provided in the cabinet.

[0011] In an optional embodiment, an emergency stop button is provided on the cabinet door.

[0012] In an optional embodiment, an indicator light panel is provided on the cabinet door.

[0013] The immersion energy storage temperature control method and energy storage cabinet provided by the present invention have the following beneficial effects compared with the prior art: first, the temperature of the battery cells of each battery panel is detected, and temperature control strategies are formulated according to the temperature difference between two adjacent layers and the temperature difference between the top and bottom layers, so as to achieve the balance of the battery cell temperature of each layer of the battery pack. The present invention performs temperature control according to the temperature difference between battery packs, saves energy, improves the temperature regulation effect, achieves temperature balance, and improves battery efficiency and safety. BRIEF DESCRIPTION OF THE DRAWINGS In order to more clearly illustrate the embodiments of the present invention or the technical solutions of the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0014] Figure 1 It is a schematic flow chart of an immersion energy storage temperature control method provided in an embodiment of the present invention.

[0015] Figure 2 It is a schematic diagram of the structure of an immersion energy storage cabinet provided by an embodiment of the present invention.

[0016] In the figure, 1-liquid cooling component, 2-energy storage inverter, 3-energy storage control system, 4-battery pack, 5-emergency stop button, 6-indicator panel, 7-dehumidifier. DETAILED DESCRIPTION

[0017] In order to enable those skilled in the art to better understand the scheme of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0018] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0019] Figure 1 is a schematic flow chart of an immersion energy storage temperature control method provided by an embodiment of the present invention, such as Figure 1 As shown, the method includes the following steps.

[0020] S1, real-time detection of the cell temperatures of the upper and lower layers of the battery pack 4.

[0021] The purpose of this step is to detect the temperature of the cells of each battery pack 4 respectively.

[0022] S2, determining whether the temperature of any battery cell of the battery pack 4 exceeds the basic temperature threshold.

[0023] First, it is determined whether the cell temperature of each battery pack 4 exceeds the basic temperature threshold, so as to ensure that the cell temperature of each battery pack 4 is within the basic temperature threshold range.

[0024] S3, if present, increase the liquid cooling flow of the battery pack 4 whose battery cell temperature exceeds the basic temperature threshold until its battery cell temperature is lower than the basic temperature threshold.

[0025] The purpose of this step is to ensure that the cell temperature of each battery pack 4 is controlled within the basic temperature threshold. If it exceeds the threshold, the liquid cooling flow rate is increased to reduce the cell temperature to ensure that the battery pack 4 can operate normally and efficiently.

[0026] S4, if not present, detect the difference between the battery cell temperatures of two adjacent layers of battery packs 4, and the difference between the battery cell temperatures of the top layer and the bottom layer of battery packs 4.

[0027] On the basis of ensuring that the temperature of the battery cells of each battery pack 4 does not exceed the basic temperature threshold, the difference between the battery cell temperatures of two adjacent layers of battery packs 4 and the difference between the battery cell temperatures of the top and bottom layers of battery packs 4 are detected to ensure that the battery cell temperatures of the battery packs 4 remain balanced, thereby further improving battery efficiency.

[0028] S5, if the difference in temperature between the cells of two adjacent battery packs 4 exceeds the first temperature threshold, the first temperature control strategy is used for temperature control; if the difference in temperature between the cells of the top and bottom battery packs 4 exceeds the second temperature threshold, the second temperature control strategy is used for temperature control.

[0029] If the temperature difference between the cells of two adjacent layers of battery packs 4 exceeds the first temperature threshold, the first temperature control strategy is used for temperature control. In this embodiment, a temperature control strategy is formulated according to the temperature of the cells of the battery packs 4 between the upper and lower adjacent layers to achieve balanced temperature of the cells between the battery packs 4. Exemplarily, the temperature difference between the upper and lower layers of cells is less than 1.5°C, otherwise the first temperature control strategy is executed. Specifically, the following steps are included.

[0030] S5.1.1, detecting the difference level between the battery cell temperatures of two adjacent layers of battery packs 4.

[0031] S5.1.2, retrieve the mapping relationship between the difference level and the flow adjustment step length, which is recorded as the first mapping relationship.

[0032] The mapping relationship between different difference levels and flow adjustment steps is pre-configured. The higher the difference level, the larger the flow adjustment step. It should be noted that different temperature differences are configured with different difference levels. The larger the temperature difference, the higher the difference level.

[0033] S5.1.3, according to the retrieved first mapping relationship, obtain a flow adjustment step size adapted to the difference level.

[0034] S5.1.4, increase the liquid cooling flow rate of the layer with higher cell temperature according to the flow adjustment step, and reduce the liquid cooling flow rate of the layer with lower cell temperature according to the flow adjustment step.

[0035] S5.1.5, after adjusting the liquid cooling flow for a preset period of time, if the difference in battery cell temperature between two adjacent layers of battery packs 4 is still not lower than the first temperature threshold, continue to increase the liquid cooling flow of the layer with higher battery cell temperature according to the flow adjustment step, and at the same time reduce the liquid cooling flow of the layer with lower battery cell temperature according to the flow adjustment step, and increase the radiator power of the liquid cooling component until the difference in battery cell temperature is lower than the first temperature threshold.

[0036] This embodiment first adjusts the liquid cooling flow rate according to the flow adjustment step length, and pre-configures the adjustment time. If the temperature difference is adjusted to the low-pressure first temperature threshold after the adjustment time, the adjustment is terminated. Otherwise, the liquid cooling flow rate is further adjusted according to the flow adjustment step length. It should be noted that the liquid cooling flow rate is adjusted again according to the flow adjustment step length on the basis of the initial adjustment, and the radiator power is increased at the same time to quickly adjust the temperature difference to meet the requirements and ensure the battery temperature balance.

[0037] When the temperature difference between the top and bottom battery packs 4 exceeds the second temperature threshold, the second temperature control strategy is used for temperature control. In addition to formulating a temperature control strategy based on the temperature difference between two adjacent layers, this embodiment also formulates a temperature control strategy based on the temperature difference between the top and bottom layers to achieve overall temperature balance and improve heat dissipation. Exemplarily, the temperature difference between the top and bottom of the battery cell is less than 2.5°C, otherwise the second temperature control strategy is executed. Specifically, the following steps are included.

[0038] S5.2.1, detecting the difference level between the battery cell temperatures of the top layer and the bottom layer battery pack 4.

[0039] S5.2.2, retrieve the mapping relationship between the difference level and the flow adjustment step length, recorded as the second mapping relationship.

[0040] S5.2.3. Obtain a flow adjustment step size that matches the difference level according to the retrieved second mapping relationship.

[0041] The mapping relationship between different difference levels and flow adjustment steps is pre-configured. The higher the difference level, the larger the flow adjustment step. It should be noted that different temperature differences are configured with different difference levels. The larger the temperature difference, the higher the difference level.

[0042] S5.2.4, divide the battery pack 4 into an upper battery pack 4 and a lower battery pack 4 according to the numbers.

[0043] It should be noted that the numbers of the battery packs 4 are pre-configured, for example, the battery packs 4 of the top 3 layers are the upper battery packs 4, and the battery packs 4 of the bottom 2 layers are the lower battery packs 4. In this embodiment, when adjusting the temperature difference of the battery cells of the bottom and top battery packs 4, the flow rate of the upper and lower battery packs 4 is adjusted as a whole, so as to improve the temperature adjustment efficiency and ensure the overall temperature balance.

[0044] S5.2.5, if the cell temperature of the top battery pack 4 is greater than that of the bottom battery pack 4, the liquid cooling flow of the upper battery pack 4 is increased according to the flow adjustment step, and at the same time, the liquid cooling flow of the lower battery pack 4 is reduced according to the flow adjustment step.

[0045] S5.2.6, if the cell temperature of the top battery pack 4 is lower than that of the bottom battery pack 4, the liquid cooling flow of the upper battery pack 4 is reduced according to the flow adjustment step, and at the same time, the liquid cooling flow of the lower battery pack 4 is increased according to the flow adjustment step.

[0046] S5.2.7, after adjusting the liquid cooling flow for a preset time, if the difference between the battery cell temperatures of the top and bottom battery packs 4 is still not lower than the second temperature threshold, continue to adjust the flow according to the flow adjustment step and increase the radiator power of the liquid cooling component until the difference in battery cell temperatures is lower than the first temperature threshold.

[0047] This embodiment first adjusts the liquid cooling flow rate according to the flow adjustment step length, and pre-configures the adjustment time. If the temperature difference is adjusted to the low-pressure second temperature threshold after the adjustment time, the adjustment is terminated. Otherwise, the liquid cooling flow rate is further adjusted according to the flow adjustment step length. It should be noted that the liquid cooling flow rate is adjusted again according to the flow adjustment step length on the basis of the initial adjustment, and the radiator power is increased at the same time to quickly adjust the temperature difference to meet the requirements and ensure the battery temperature balance.

[0048] Figure 2 is a schematic diagram of the structure of an immersion energy storage cabinet provided by an embodiment of the present invention, such as Figure 2 As shown, the energy storage cabinet of this embodiment includes a cabinet body and a cabinet door. Three spaces are arranged in sequence from top to bottom in the cabinet body to achieve reasonable planning of the internal space. From top to bottom, they are the first space, the second space and the third space.

[0049] The first space is provided with multiple layers of battery packs 4 arranged up and down; the battery packs 4 are completely immersed in a special static coolant, which effectively isolates the battery packs 4 from direct contact with the external environment, reducing the impact of external factors on battery performance. At the same time, the coolant, as a heat conduction medium, can quickly absorb the heat generated by the battery pack 4. A liquid cooling plate is installed at the bottom of the battery pack 4, which is in direct contact with the static coolant. When the battery pack 4 is working, the heat generated is transferred to the liquid cooling plate through the bottom of the battery pack 4. The liquid cooling plate uses its own thermal conductivity to further transfer the heat to the coolant. The coolant evenly distributes and carries away the heat through heat conduction.

[0050] The second space is provided with an energy storage converter 2 and an energy storage control system 3. The energy storage control system 3 includes a battery management subsystem and an energy management subsystem. The battery management subsystem (BMS) realizes the optimized control and comprehensive management of the battery operation state, and executes the immersion energy storage temperature control method of the above embodiment.

[0051] The third space is provided with a liquid cooling assembly 1. The liquid cooling unit is connected to the liquid cooling plate and is responsible for discharging the heat in the coolant out of the cabinet. The liquid cooling unit drives the coolant to flow through a circulation pump and brings the heat to the radiator in the unit. The radiator dissipates the heat into the air through natural convection or forced convection, thereby realizing external heat exchange. At the same time, the liquid cooling unit also has the function of circulating and filtering the coolant to ensure the cleanliness and heat conduction efficiency of the coolant. A dehumidifier 7 is also provided in the cabinet for dehumidification and condensation prevention. An emergency stop button 5 and an indicator panel 6 are provided on the cabinet door. The emergency stop button 5 is used for external emergency stop, and the indicator panel 6 is used for power supply, operation, and fault indication.

[0052] The above disclosure is only a preferred embodiment of the present invention, but the present invention is not limited thereto. Any non-creative changes that can be thought of by a person skilled in the art, as well as several improvements and modifications made without departing from the principle of the present invention, should fall within the protection scope of the present invention.

Claims

1. An immersion energy storage temperature control method, characterized in that: The following steps are involved: Real-time detection of the battery cell temperature of each layer of the upper and lower battery packs; Determine whether the temperature of the battery cell of the battery pack exceeds the basic temperature threshold; If present, increase the liquid cooling flow of the battery pack whose cell temperature exceeds the basic temperature threshold until its cell temperature is lower than the basic temperature threshold; If not present, detect the difference between the cell temperatures of two adjacent battery packs, and the difference between the cell temperatures of the top and bottom battery packs; If the temperature difference between the cells of two adjacent battery packs exceeds a first temperature threshold, the first temperature control strategy is used for temperature control; if the temperature difference between the cells of the top and bottom battery packs exceeds a second temperature threshold, the second temperature control strategy is used for temperature control.

2. The immersion energy storage temperature control method according to claim 1, characterized in that: The first temperature control strategy is used for temperature control, which specifically includes: Detect the difference level of the temperature difference between the cells of two adjacent battery packs; Retrieving a mapping relationship between a difference level and a flow adjustment step length, which is recorded as a first mapping relationship; According to the retrieved first mapping relationship, a flow adjustment step length adapted to the difference level is obtained; Increase the liquid cooling flow rate of the layer with higher cell temperature according to the flow adjustment step length, and reduce the liquid cooling flow rate of the layer with lower cell temperature according to the flow adjustment step length; After adjusting the liquid cooling flow for a preset time, if the difference in battery cell temperature between two adjacent battery pack layers is still not lower than the first temperature threshold, the liquid cooling flow of the layer with higher battery cell temperature will continue to be increased according to the flow adjustment step. At the same time, the liquid cooling flow of the layer with lower battery cell temperature will be reduced according to the flow adjustment step, and the radiator power of the liquid cooling component will be increased until the difference in battery cell temperature is lower than the first temperature threshold.

3. The immersion energy storage temperature control method according to claim 1, characterized in that: The second temperature control strategy is used for temperature control, including: Detect the difference level between the top and bottom battery pack cell temperatures; Retrieving a mapping relationship between a difference level and a flow adjustment step length, which is recorded as a second mapping relationship; According to the retrieved second mapping relationship, a flow adjustment step length adapted to the difference level is obtained; Divide the battery packs into upper battery packs and lower battery packs according to the labels; If the cell temperature of the top battery pack is greater than that of the bottom battery pack, the liquid cooling flow rate of the upper battery pack is increased according to the flow adjustment step length, and the liquid cooling flow rate of the lower battery pack is reduced according to the flow adjustment step length; If the cell temperature of the top battery pack is lower than that of the bottom battery pack, the liquid cooling flow rate of the upper battery pack is reduced according to the flow adjustment step length, and the liquid cooling flow rate of the lower battery pack is increased according to the flow adjustment step length; After adjusting the liquid cooling flow for a preset time, if the difference in battery cell temperature between the top and bottom battery packs is still not lower than the second temperature threshold, continue to adjust the flow according to the flow adjustment step and increase the radiator power of the liquid cooling component until the difference in battery cell temperature is lower than the first temperature threshold.

4. An immersion energy storage cabinet, characterized in that: The cabinet comprises a cabinet body and a cabinet door, wherein a first space, a second space and a third space are sequentially arranged in the cabinet body from top to bottom; The first space is provided with a multi-layer battery pack arranged up and down; the second space is provided with an energy storage converter and an energy storage control system; the third space is provided with a liquid cooling component; Among them, the energy storage control system implements the immersion energy storage temperature control method described in any one of claims 1-3.

5. The submersible energy storage cabinet according to claim 4, characterized in that: The energy storage control system includes a battery management subsystem and an energy management subsystem; wherein the battery management subsystem executes the immersion energy storage temperature control method described in any one of claims 1-3.

6. The submersible energy storage cabinet according to claim 5, characterized in that: A dehumidifier is also provided in the cabinet.

7. The submersible energy storage cabinet according to claim 5, characterized in that: An emergency stop button is provided on the cabinet door.

8. The submersible energy storage cabinet according to claim 5, characterized in that: An indicator light panel is arranged on the cabinet door.

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