Energy storage system and energy storage cooling method

Abstract

The invention discloses an energy storage system and an energy storage cooling method. According to the energy storage system, a battery rack is provided with a plurality of laminates, battery clusters are arranged on the laminates, a cooling device comprises refrigeration equipment, a top-layer cooling air duct, a connecting air duct and a plurality of bottom-layer cooling air ducts, and the bottom-layer cooling air ducts and the top-layer cooling air duct are connected to the refrigeration equipment; the top-layer cooling air duct and the bottom-layer cooling air duct are in one-to-one correspondence with the battery clusters and are arranged above the battery clusters, a plurality of cooling fans are arranged on the top-layer cooling air duct and the bottom-layer cooling air duct at intervals, the cooling fans at least correspond to two battery units in the battery clusters, and the refrigeration equipment, the battery clusters and the cooling fans are all connected with the control device; the refrigeration equipment is used for providing cooling air; the cooling fan is used for controlling the amount of cooling air flowing to the battery unit; the control device is used for controlling the rotating speed of the cooling fan according to the temperature of the battery unit corresponding to the cooling fan. By adopting the scheme, the temperature uniformity of the battery cluster is ensured, and the service life of the energy storage system is prolonged.

Description

Technical Field

[0001] The present invention relates to the field of energy storage technology, and in particular to an energy storage system and an energy storage cooling method. Background Art

[0002] The containerized battery energy storage system integrates battery clusters, battery management systems, AC / DC conversion devices, thermal management systems and fire protection systems in a standard container. It has the advantages of high integration, small footprint, large storage capacity, convenient transportation and easy installation. It is one of the most widely used energy storage technologies at present.

[0003] In the prior art, containerized energy storage systems mostly use forced air cooling for heat dissipation. The batteries in containerized energy storage systems are closely arranged and the container environment is relatively closed. The heat dissipation airflow in the containerized energy storage system is difficult to distribute evenly, which also causes the battery cluster in the containerized energy storage system to be prone to uneven temperature, affecting the service life of the containerized energy storage system. Summary of the invention

[0004] The present invention provides an energy storage system and an energy storage cooling method to ensure the temperature uniformity of a battery cluster and to increase the service life of the energy storage system.

[0005] According to one aspect of the present invention, there is provided an energy storage system, the energy storage system comprising: at least one battery rack, at least one cooling device, a plurality of battery clusters and a control device;

[0006] The battery rack has a plurality of layer plates, the battery cluster is arranged on the layer plates along the length direction of the battery rack, the cooling device comprises a refrigeration device, a top layer cooling air duct, a connecting air duct and a plurality of bottom layer cooling air ducts, the bottom layer cooling air duct is connected to the top layer cooling air duct through the connecting air duct, the top layer cooling air duct is connected to the refrigeration device, the top layer cooling air duct and the bottom layer cooling air duct correspond to the battery cluster one by one and are arranged above the battery cluster along the length direction of the battery rack, the top layer cooling air duct and the bottom layer cooling air duct are both provided with a plurality of cooling fans at intervals, the cooling fans correspond to at least two battery cells in the battery cluster, the refrigeration device, the battery cluster and the cooling fans are all connected to the control device;

[0007] The refrigeration equipment is used to provide cooling air; the cooling fan is used to control the amount of cooling air flowing to the battery unit; the control device is used to control the speed of the cooling fan according to the temperature of the battery unit corresponding to the cooling fan to cool the battery unit.

[0008] Optionally, the connecting air duct is connected to the top cooling air duct through the opening of the top cooling air duct, and the bottom cooling air duct is connected to the connecting air duct through the opening of the connecting air duct, and air guide plates are provided at the opening positions of the top cooling air duct and the connecting air duct.

[0009] Optionally, a sealing rubber ring is provided at the connection between the top-layer cooling air duct and the refrigeration device, a sealing rubber ring is provided at the opening of the top-layer cooling air duct, and a sealing rubber ring is provided at the opening of the connecting air duct.

[0010] Optionally, the cooling fan corresponds to four battery units.

[0011] Optionally, the battery cluster includes a plurality of the battery cells and a plurality of temperature sensors, the temperature sensors correspond to the battery cells one by one and are arranged on the battery cells, and the temperature sensors are connected to the control device.

[0012] Optionally, adjacent battery cells in the battery cluster are spaced apart from each other.

[0013] Optionally, the energy storage system further comprises: a fire-fighting device;

[0014] The fire-fighting device includes a fire-fighting device, a plurality of fire-fighting pipelines and a plurality of nozzles, the fire-fighting pipeline is connected to the fire-fighting device, the fire-fighting device and the fire-fighting pipeline are also connected to the control device, the fire-fighting pipeline is arranged on the side of the top cooling air duct and the side of the bottom cooling air duct, and is arranged along the length direction of the battery rack, and the nozzles are arranged on the fire-fighting pipeline at intervals;

[0015] The control device is also used to control the start and stop of the fire extinguishing equipment, and control the conduction of the corresponding fire protection pipeline according to the location of the battery unit that has caught fire.

[0016] Optionally, the energy storage system further comprises: a box;

[0017] The battery rack, the cooling device, the battery cluster and the control device are all arranged in the box.

[0018] According to another aspect of the present invention, there is further provided an energy storage cooling method, which is performed by the energy storage system provided by any of the above embodiments, wherein the energy storage system includes a cooling fan and a refrigeration device; the energy storage cooling method includes:

[0019] Acquire the temperature of the battery cell with the highest temperature and the temperature of the battery cell with the lowest temperature among the multiple battery cells corresponding to the cooling fan;

[0020] Calculating a battery cell temperature difference according to the temperature of the battery cell with the highest temperature and the temperature of the battery cell with the lowest temperature;

[0021] If the battery cell temperature difference is greater than or equal to a preset temperature difference and / or the temperature of the battery cell with the highest temperature is greater than or equal to a preset battery cell temperature, determining whether the speed of the cooling fan reaches a maximum speed;

[0022] If the speed of the cooling fan reaches the maximum speed, the refrigeration device is controlled to reduce the temperature of the cooling air generated by the refrigeration device, and the temperature of the battery cell with the highest temperature and the temperature of the battery cell with the lowest temperature are re-obtained after a preset delay;

[0023] If the speed of the cooling fan does not reach the maximum speed, the cooling fan is controlled to increase the speed, and the temperature of the battery cell with the highest temperature and the temperature of the battery cell with the lowest temperature are re-obtained after a preset delay;

[0024] If the battery cell temperature difference is less than the preset temperature difference and the temperature of the battery cell with the highest temperature is less than the preset battery cell temperature, the cooling fan is controlled to rotate at an initial speed and the temperature of the battery cell with the highest temperature and the temperature of the battery cell with the lowest temperature are re-obtained.

[0025] Optionally, before obtaining the temperature of the battery cell with the highest temperature and the temperature of the battery cell with the lowest temperature among the multiple battery cells corresponding to the cooling fan, the method further includes:

[0026] Acquire the current state of the energy storage system and the temperature of the environment in which the energy storage system is located;

[0027] If the current state of the energy storage system is running, determining whether the temperature of the environment in which the energy storage system is located reaches a preset ambient temperature;

[0028] If the temperature of the environment in which the energy storage system is located reaches a preset ambient temperature, the cooling fan and the refrigeration device are started, and the temperature of the battery cell with the highest temperature and the temperature of the battery cell with the lowest temperature among the multiple battery cells corresponding to the cooling fan are obtained;

[0029] If the temperature of the environment in which the energy storage system is located does not reach the preset ambient temperature, re-obtaining the temperature of the environment in which the energy storage system is located;

[0030] If the current state of the energy storage system is standby, the current state of the energy storage system is re-acquired.

[0031] Each layer of the battery rack of the energy storage system of the embodiment of the present invention is provided with a battery cluster, and a cooling air duct is provided above the battery cluster on each layer of the battery rack to cool the battery cluster. Compared with the prior art, the present embodiment adopts a layered cooling method to cool each battery cluster, which is conducive to ensuring the temperature uniformity of the battery cluster and prolonging the service life of the energy storage system.

[0032] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. 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 creative work.

[0034] Figure 1 is a control connection schematic diagram of an energy storage system provided by an embodiment of the present invention;

[0035] Figure 2 is a structural schematic diagram of an energy storage system provided by an embodiment of the present invention;

[0036] Figure 3 is a heat dissipation schematic diagram of a cooling fan provided by an embodiment of the present invention;

[0037] Figure 4 is a structural schematic diagram of another energy storage system provided by an embodiment of the present invention;

[0038] Figure 5 is a partial enlarged view of an energy storage system provided by an embodiment of the present invention;

[0039] Figure 6 is a partial enlarged view of another energy storage system provided by an embodiment of the present invention;

[0040] Figure 7 is a structural schematic diagram of another energy storage system provided by an embodiment of the present invention;

[0041] Figure 8 is a control connection schematic diagram of an energy storage system provided by an embodiment of the present invention;

[0042] Fig. 9 is a top view of an energy storage system provided by an embodiment of the present invention;

[0043] Fig.10 is a flow chart of an energy storage cooling method provided by an embodiment of the present invention;

[0044] Fig.11 It is a flow chart of another energy storage cooling method provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0045] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0046] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0047] An embodiment of the present invention provides an energy storage system. Each layer of the battery rack of the energy storage system provided by this embodiment is provided with a battery cluster, and a cooling air duct is provided above the battery cluster on each layer of the battery rack to cool the battery cluster. Compared with the prior art, this embodiment is conducive to ensuring the temperature uniformity of the battery cluster and improving the service life of the energy storage system. Figure 1 It is a control connection diagram of an energy storage system provided by an embodiment of the present invention. Figure 2 Schematic diagram of the structure of an energy storage system provided by an embodiment of the present invention. Figure 1 and Figure 2 The energy storage system includes: a box body and at least one battery rack 110 arranged in the box body, at least one cooling device 120, a plurality of battery clusters 130 and a control device 140.

[0048] The battery rack 110 has a plurality of layers, and the battery cluster 130 is arranged on the layers along the length direction of the battery rack 110. The cooling device 120 includes a refrigeration device 121, a top cooling air duct 122, a connecting air duct 123, and a plurality of bottom cooling air ducts 124. The bottom cooling air duct 124 is connected to the top cooling air duct 122 through the connecting air duct 123. The top cooling air duct 122 is connected to the refrigeration device 121. The top cooling air duct 122 and the bottom cooling air duct 124 correspond to the battery cluster 130 one by one and are arranged on the battery cluster 110 along the length direction of the battery rack 110. Above the top cooling duct 122 and the bottom cooling duct 124, multiple cooling fans 125 are arranged at intervals. The cooling fans 125 correspond to at least two battery cells in the battery cluster 130. The refrigeration device 121, the battery cluster 130 and the cooling fans 125 are all connected to the control device 140; the refrigeration device 121 is used to provide cooling air; the cooling fan 125 is used to control the amount of cooling air flowing to the battery cell; the control device 140 is used to control the speed of the cooling fan 125 according to the temperature of the battery cell corresponding to the cooling fan 125 to cool the battery cell. Among them, the battery cell can be a single cell or a battery module composed of multiple cells. For example, the cell in the battery cell can be a lead-acid cell or a lithium-ion cell, which is not limited in this embodiment.

[0049] Specifically, a battery cluster 130 is arranged on each layer of the battery rack 110, and the battery clusters 130 on each layer of the battery rack 110 are arranged in a single layer. That is to say, the battery clusters 130 are laid flat on the layers of the battery rack 110. A cooling air duct is arranged above the battery clusters 130 on each layer of the battery rack 110, and the cooling air duct is also arranged along the length direction of the battery rack 110. Among them, the cooling air duct includes a top cooling air duct 122 and a bottom cooling air duct 124. The top cooling air duct 122 corresponds to the battery cluster 130 on the uppermost layer of the battery rack 110, and is arranged above the battery cluster 130 on the uppermost layer of the battery rack 110; each bottom cooling air duct 124 corresponds one by one to the remaining battery clusters 130 in the battery rack 110, and is arranged above the corresponding battery cluster 130. Cooling fans 125 are provided on both the top cooling air duct 122 and the bottom cooling air duct 124. The exhaust direction of the cooling fan 125 is toward the outside of the cooling air duct, that is, toward the battery cluster 130. When the cooling fan 125 is started, the cooling fan 125 blows the cooling air in the cooling air duct toward the corresponding battery cell, thereby cooling the battery cluster 130. Each cooling fan 125 corresponds to at least two battery cells, and each battery cell in the battery cluster 130 has a corresponding cooling fan 125.

[0050] When the energy storage system is running, the control device 140 detects the temperature of the environment in which the energy storage system is located. When the temperature of the environment in which the energy storage system is located is greater than the preset ambient temperature, the control device 140 controls the refrigeration equipment 121 and the cooling fan 125 to start, so as to deliver cooling air to the top cooling air duct 122 and the bottom cooling air duct 124. Exemplarily, the temperature of the environment in which the energy storage system is located can be obtained by a temperature sensor in the environment in which the energy storage system is located, and this embodiment does not limit this. Among them, the refrigeration equipment 121 can be an air conditioner. When the energy storage system is running, the temperature of the environment in which the energy storage system is located is mainly determined by the temperature of each battery cluster 130 in the energy storage system. When the temperature of the battery cluster 130 increases, the temperature of the environment in which the energy storage system is located also increases accordingly. Therefore, the temperature of the environment in which the energy storage system is located also represents the temperature of the battery cluster 130. In addition, the control device 140 also monitors the temperature of each battery cell in the battery cluster. When the battery cell temperature difference between the battery cell with the highest temperature and the battery cell with the lowest temperature among at least two battery cells corresponding to a cooling fan 125 is greater than or equal to the preset temperature difference and / or the temperature of the battery cell with the highest temperature among at least two battery cells corresponding to the cooling fan 125 is greater than the preset battery cell temperature, the control device 140 executes different cooling strategies according to the rotation speed of the cooling fan 125. When the rotation speed of the cooling fan 125 reaches the maximum rotation speed, the control device 140 controls the refrigeration device 121 to reduce the temperature of the generated cooling air; when the rotation speed of the cooling fan 125 does not reach the maximum rotation speed, the control device 140 controls the cooling fan 125 to increase the rotation speed. Among them, since the difference in ambient temperature between adjacent battery cells in the battery cluster 130 is not large, in practical application, multiple battery cells can be cooled by one cooling fan 125. Figure 3 is a heat dissipation schematic diagram of a cooling fan provided by an embodiment of the present invention. Figure 3 , one cooling fan 125 can correspond to four battery units.

[0051] It should be noted that the preset ambient temperature is a preset temperature threshold value at which the energy storage system needs to be cooled down, the preset temperature difference is the maximum battery cell temperature difference between the battery cell with the highest temperature and the battery cell with the lowest temperature, and the preset battery cell temperature is the maximum battery cell temperature allowed by the preset energy storage system. In actual application, the preset ambient temperature, preset temperature difference and preset battery cell temperature can be set according to actual needs, and this embodiment does not impose any restrictions on this.

[0052] Each layer of the battery rack 110 of the energy storage system of the embodiment of the present invention is provided with a battery cluster 130, and a cooling air duct is provided above the battery cluster 130 on each layer of the battery rack 110 to cool the battery cluster 130. Compared with the prior art, the present embodiment adopts a layered cooling method to cool each battery cluster 130, which is conducive to ensuring the temperature uniformity of the battery cluster 130 and improving the service life of the energy storage system.

[0053] Figure 4 is a schematic diagram of another energy storage system provided by an embodiment of the present invention. Based on the above embodiment, optionally, refer to Figure 4 The connecting air duct 123 is connected to the top cooling air duct 122 through the opening of the top cooling air duct 122, and the bottom cooling air duct 124 is connected to the connecting air duct 123 through the opening of the connecting air duct 123. Wind guide plates 126 are provided at the opening positions of the top cooling air duct 122 and the connecting air duct 123.

[0054] Specifically, when the cooling air generated by the refrigeration equipment 121 enters the top-layer cooling air duct 122, the air guide plate 126 in the top-layer cooling air duct 122 divides the cooling air so that the cooling air is divided into two parts, one part flows into the top-layer cooling air duct 122, and the other part flows into the connecting air duct 123. When the cooling air enters the connecting air duct 123, the air guide plate 126 in the connecting air duct 123 divides the cooling air entering the connecting air duct 123 so that the cooling air flows into each bottom-layer cooling air duct 124.

[0055] Figure 5 It is a partially enlarged view of an energy storage system provided by an embodiment of the present invention. Figure 6 is a partial enlarged diagram of another energy storage system provided by an embodiment of the present invention. Based on the above embodiments, optionally, refer to Figure 5 and Figure 6 A sealing rubber ring 127 is provided at the connection between the top cooling air duct 122 and the refrigeration device 121 , a sealing rubber ring 127 is provided at the opening of the top cooling air duct 122 , and a sealing rubber ring 127 is provided at the opening of the connecting air duct 123 .

[0056] Among them, the sealing rubber ring 127 seals the connection between the top cooling air duct 122 and the refrigeration equipment 121, the connection between the top cooling air duct 122 and the connecting air duct 123, and the connection between the connecting air duct 123 and the bottom cooling air duct 124 to ensure the air tightness of the cooling device 120, which is beneficial to avoid the outflow of cooling air and improve the cooling efficiency of the energy storage system.

[0057] On the basis of the above embodiments, optionally, the battery cluster 130 includes a plurality of battery cells and a plurality of temperature sensors, the temperature sensors correspond to the battery cells one by one and are arranged on the battery cells, and the temperature sensors are connected to the control device 140 .

[0058] Specifically, the temperature sensor detects the temperature of each battery cell in the battery cluster 130. The control device 140 obtains the temperature of the battery cells detected by each temperature sensor in the battery cluster 130, and controls the rotation speed of the cooling fan 125 according to the temperature of each battery cell, thereby cooling the battery cells in the battery cluster 130. Exemplarily, the temperature sensor may include an NTC resistor (Negative Temperature Coefficient thermistor) or a PTC resistor (Positive Temperature Coefficient thermistor).

[0059] On the basis of the above embodiments, optionally, adjacent battery cells in the battery cluster 130 are spaced apart from each other. Specifically, the spacing between adjacent battery cells forms a cooling air flow channel, and when the cooling air blows toward the battery cells, the cooling air can flow through the cooling air flow channel between adjacent battery cells, thereby increasing the contact area and contact time between the cooling air and the battery cells, which is beneficial to improving the heat dissipation effect of each battery cell in the battery cluster 130.

[0060] Figure 7 It is a structural schematic diagram of another energy storage system provided by an embodiment of the present invention. Figure 8 It is a control connection diagram of an energy storage system provided by an embodiment of the present invention. Fig. 9 FIG. 1 is a top view of an energy storage system provided by an embodiment of the present invention. Based on the above embodiments, optionally, Figure 7 , Figure 8 and Fig. 9 The energy storage system also includes: a fire-fighting device 150.

[0061] The fire-fighting device 150 includes a fire-fighting device 151, a plurality of fire-fighting pipes 152 and a plurality of nozzles 153. The fire-fighting pipes 152 are connected to the fire-fighting device 151. The fire-fighting device 151 and the fire-fighting pipes 152 are also connected to the control device 140. The fire-fighting pipes 152 are arranged on the sides of the top-layer cooling air duct 122 and the sides of the bottom-layer cooling air duct 124, and are arranged along the length direction of the battery rack 110. The nozzles 153 are arranged at intervals on the fire-fighting pipes 152. The control device 140 is also used to control the start and stop of the fire-fighting device 151, and to control the conduction of the corresponding fire-fighting pipes 152 according to the location of the battery unit that has caught fire.

[0062] Specifically, the control device 140 obtains the temperature of each battery cell in the battery cluster 130. When the temperature of a battery cell in the battery cluster 130 is greater than the fire threshold, the control device 140 considers that the battery cell is on fire. At this time, the control device 140 controls the fire extinguishing device 150 to start, and controls the fire fighting pipeline 152 above the position of the battery cell to be turned on, so as to extinguish the fire of the battery cell. Among them, a switch control is provided in the fire fighting pipeline 152, and the control device 140 realizes the conduction control of the fire fighting pipeline 152 by controlling the conduction of the switch control. When the fire fighting pipeline 152 is turned on, the fire extinguishing medium in the fire fighting device 151 enters the fire fighting pipeline 152, and is sprayed to the battery cluster 130 through the nozzle 153 provided on the fire fighting pipeline 152. Exemplarily, the fire extinguishing medium in the fire fighting device 151 can be perfluorohexanone. It should be noted that the control device 140 can determine the battery cluster 130 where the battery cell is located according to the communication position of the battery cell, and determine the fire protection pipeline 152 that needs to be connected according to the position of the battery cluster 130 in the battery rack 110. Among them, the fire threshold is a preset threshold value for determining whether the battery cell is on fire. In actual application, the fire threshold can be set according to actual needs, and this embodiment does not limit this.

[0063] Based on the above embodiments, optionally, refer to Fig. 9 The energy storage system further includes a box 160. The battery rack 110, the cooling device 120, the battery cluster 130 and the control device 140 are all arranged in the box 160. Exemplarily, the box 160 may be a container.

[0064] An embodiment of the present invention also provides an energy storage cooling method. Fig.10 This is a flow chart of an energy storage cooling method provided by an embodiment of the present invention. The energy storage cooling method is executed by the energy storage system provided by any of the above embodiments, and the energy storage system includes a cooling fan and a refrigeration device; the energy storage cooling method includes:

[0065] S110 , obtaining the temperature of the battery cell with the highest temperature and the temperature of the battery cell with the lowest temperature among the plurality of battery cells corresponding to the cooling fan.

[0066] Specifically, one cooling fan corresponds to at least two battery cells. The temperature of the battery cell corresponding to the cooling fan can be obtained by a temperature sensor. For example, the battery cell with the highest temperature and the battery cell with the lowest temperature can be obtained by comparing the temperatures of the battery cells corresponding to the cooling fan.

[0067] S120 , calculating a battery cell temperature difference according to the temperature of the battery cell with the highest temperature and the temperature of the battery cell with the lowest temperature.

[0068] Specifically, the difference between the temperature of the battery cell with the highest temperature and the temperature of the battery cell with the lowest temperature is the battery cell temperature difference. The battery cell temperature difference represents the maximum temperature difference between the battery cells corresponding to the cooling fan.

[0069] S130, determining whether the battery cell temperature difference is less than a preset temperature difference and whether the temperature of the battery cell with the highest temperature is less than a preset battery cell temperature; if not, executing S140; if yes, executing S170.

[0070] Specifically, the preset battery cell temperature is a preset maximum battery cell temperature allowed by the energy storage system. The preset temperature difference is a preset maximum battery cell temperature difference between a battery cell with the highest temperature and a battery cell with the lowest temperature.

[0071] When the temperature difference of the battery cells is greater than or equal to the preset temperature difference, the temperature difference between the battery cell with the highest temperature and the battery cell with the lowest temperature among the multiple battery cells corresponding to the cooling fan exceeds the maximum temperature difference allowed when the battery cells are working. At this time, the working performance of the battery cells corresponding to the cooling fan is too different, that is, the temperature uniformity of each battery cell in the battery cluster is low. In this case, it is necessary to reduce the temperature difference between the battery cell with the highest temperature and the battery cell with the lowest temperature to ensure that the working performance of the battery cells is close.

[0072] When the temperature of the battery cell with the highest temperature is greater than or equal to the preset battery cell temperature, there is at least one over-temperature battery cell among the multiple battery cells corresponding to the cooling fan. At this time, there is a risk of thermal runaway of the battery cell. In this case, it is necessary to control the temperature of the battery cell, that is, to accelerate the heat dissipation efficiency of the battery cell so that the temperature of the battery cell is maintained below the preset battery cell temperature, thereby avoiding thermal runaway of the battery cell.

[0073] S140, determining whether the speed of the cooling fan reaches the maximum speed; if so, executing S150; if not, executing S160.

[0074] Specifically, when the cooling fan speed reaches the maximum speed, the cooling fan cannot continue to increase the amount of cooling air blown to the battery cell, that is, at this time, the cooling efficiency of the battery cell cannot be improved by increasing the speed of the cooling fan. In this case, it is necessary to control the refrigeration equipment to reduce the temperature of the cooling air it generates, so as to increase the heat exchange efficiency of the cooling air, thereby improving the cooling efficiency of the battery cell. When the cooling fan speed does not reach the maximum speed, the cooling fan speed is controlled to increase, so as to increase the amount of cooling air blown to the battery cell, thereby increasing the heat exchange efficiency of the cooling air blown to the battery cell, so as to improve the cooling efficiency of the battery cell.

[0075] S150, controlling the refrigeration device to lower the temperature of the cooling air generated by the refrigeration device, and re-obtaining the temperature of the battery cell with the highest temperature and the temperature of the battery cell with the lowest temperature after a preset delay.

[0076] Exemplarily, the refrigeration equipment can control the temperature of the cooling air by adjusting the power of the compressor, the opening of the expansion valve and / or the heat dissipation efficiency of the condenser. Specifically, it takes a certain amount of time for the temperature of the battery cell corresponding to the cooling fan to decrease. Therefore, after the temperature of the cooling air of the refrigeration equipment decreases, a delay is performed for a period of time to re-acquire the temperature of the battery cell with the highest temperature and the temperature of the battery cell with the lowest temperature, so as to re-evaluate the battery cell temperature difference of the battery cell corresponding to the cooling fan, so that the battery cell has enough time to cool down. It should be noted that the preset time is the preset cooling time of the battery cell. In actual application, the preset time can be set according to actual needs, and this embodiment does not limit this.

[0077] S160, controlling the cooling fan to increase the rotation speed, and re-obtaining the temperature of the battery cell with the highest temperature and the temperature of the battery cell with the lowest temperature after a preset delay.

[0078] Specifically, the amount of cooling air during battery cell cooling is related to the speed of the cooling fan. When the speed of the cooling fan is higher, the amount of cooling air blown to the battery cell is larger, and the heat dissipation efficiency of the battery cell is higher. Therefore, when the temperature difference of the battery cell is greater than the preset temperature difference, the heat dissipation efficiency of the battery cell can be improved by increasing the speed of the cooling fan. It takes a certain amount of time for the temperature of the battery cell corresponding to the cooling fan to decrease. Therefore, after a period of delay after the speed of the cooling fan is increased, the temperature of the battery cell with the highest temperature and the temperature of the battery cell with the lowest temperature are re-obtained, so as to re-evaluate the battery cell temperature difference of the battery cell corresponding to the cooling fan, so that the battery cell has enough time to cool down. It should be noted that the preset time is the cooling time of the battery cell set in advance. In actual application, the preset time can be set according to actual needs, and this embodiment does not limit this.

[0079] S170: Control the cooling fan to rotate at an initial speed, and re-acquire the temperature of the battery cell with the highest temperature and the temperature of the battery cell with the lowest temperature.

[0080] Specifically, when the cooling fan rotates at the initial speed, the temperature difference between the battery cells corresponding to the cooling fan is not large, that is, the battery cell temperature difference between the battery cell with the highest temperature and the battery cell with the lowest temperature among the battery cells corresponding to the cooling fan is less than the preset temperature difference, and the temperature of the battery cell with the highest temperature among the battery cells corresponding to the cooling fan is less than the preset battery cell temperature. The working performance of each battery cell is similar. The heat dissipation efficiency of the cooling fan at the initial speed can maintain the temperature stability and balance of the battery cells, and the battery cells corresponding to the cooling fan do not need to be further cooled. It should be noted that the initial speed is the preset default speed of the cooling fan. When the cooling device is started, the cooling fan rotates at this speed. In actual application, the initial speed can be set according to actual needs, and this embodiment does not limit this.

[0081] Fig.11 is a flow chart of another energy storage cooling method provided by an embodiment of the present invention. Based on the above embodiment, optionally, refer to Fig.11 , before obtaining the temperature of the battery cell with the highest temperature and the temperature of the battery cell with the lowest temperature among the multiple battery cells corresponding to the cooling fan, it also includes:

[0082] S210: Obtain the current state of the energy storage system and the temperature of the environment in which the energy storage system is located.

[0083] Specifically, the energy storage system includes an operating state and a standby state. When the energy storage system is in the operating state, the energy storage system needs to discharge or charge externally; when the energy storage system is in the standby state, there is no external interaction, that is, the energy storage system does not discharge or charge at this time. Therefore, when applied, the state of the energy storage system can be obtained according to the current of the energy storage system.

[0084] For example, the temperature of the environment in which the energy storage system is located can be obtained by detecting a temperature sensor, or can be obtained by estimating the temperature of each battery cell in the battery cluster, which is not limited in this embodiment.

[0085] S220, determine whether the current state of the energy storage system is running; if so, execute S230; if not, execute S260.

[0086] Specifically, when the energy storage system is in operation, each battery cluster in the energy storage system is charging or discharging, each battery cell in the battery cluster is in working state, and the ambient temperature of the energy storage system is affected by the heat generated by each battery cell in the battery cluster when working, that is, the ambient temperature of the energy storage system at this time mainly depends on the temperature of each battery cell in the battery cluster; when the energy storage system is in standby state, the energy storage system is not working, and the ambient temperature of the energy storage system mainly depends on the temperature of the natural environment.

[0087] S230, determining whether the temperature of the environment in which the energy storage system is located reaches a preset ambient temperature; if so, executing S240; if not, executing S250.

[0088] Specifically, the preset ambient temperature is the threshold value for judging whether the battery cluster needs to be cooled. When the temperature of the environment in which the energy storage system is located reaches the preset ambient temperature, it indicates that the heat exchange between the energy storage system and the natural environment can no longer meet the heat dissipation requirements of the energy storage system. At this time, it is necessary to start the cooling device (cooling fan and refrigeration equipment) for cooling; when the temperature of the environment in which the energy storage system is located does not reach the preset ambient temperature, it indicates that the heat exchange between the energy storage system and the natural environment can meet the heat dissipation requirements of the energy storage system, and the operation of the energy storage system is stable.

[0089] S240: Start a cooling fan and a refrigeration device, and obtain the temperature of the battery cell with the highest temperature and the temperature of the battery cell with the lowest temperature among the multiple battery cells corresponding to the cooling fan.

[0090] Specifically, after the cooling device (cooling fan and refrigeration equipment) is started, the heat dissipation of the energy storage system is mainly undertaken by the cooling device. The refrigeration equipment is used to generate the cooling air required for the heat dissipation of the energy storage system, and the cooling fan is used to control the amount of cooling air blown to the battery cluster in the energy storage system. The speed of the cooling fan is related to the temperature of the battery cell corresponding to the cooling fan.

[0091] S250: Re-obtain the temperature of the environment in which the energy storage system is located.

[0092] S260: Re-obtain the current state of the energy storage system.

[0093] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and this document does not limit this.

[0094] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An energy storage system, characterized in that: include: at least one battery rack, at least one cooling device, a plurality of battery clusters and a control device; The battery rack has a plurality of layer plates, the battery cluster is arranged on the layer plates along the length direction of the battery rack, the cooling device comprises a refrigeration device, a top layer cooling air duct, a connecting air duct and a plurality of bottom layer cooling air ducts, the bottom layer cooling air duct is connected to the top layer cooling air duct through the connecting air duct, the top layer cooling air duct is connected to the refrigeration device, the top layer cooling air duct and the bottom layer cooling air duct correspond to the battery cluster one by one and are arranged above the battery cluster along the length direction of the battery rack, a plurality of cooling fans are arranged at intervals on the top layer cooling air duct and the bottom layer cooling air duct, the cooling fans correspond to at least two battery cells in the battery cluster, and the refrigeration device, the battery cluster and the cooling fans are all connected to the control device; The refrigeration equipment is used to provide cooling air; the cooling fan is used to control the amount of cooling air flowing to the battery unit; the control device is used to control the speed of the cooling fan according to the temperature of the battery unit corresponding to the cooling fan to cool the battery unit.

2. The energy storage system according to claim 1, characterized in that: The connecting air duct is connected to the top cooling air duct through the opening of the top cooling air duct, and the bottom cooling air duct is connected to the connecting air duct through the opening of the connecting air duct. Wind guide plates are provided at the opening positions of the top cooling air duct and the connecting air duct.

3. The energy storage system according to claim 2, characterized in that: A sealing rubber ring is provided at the connection between the top cooling air duct and the refrigeration device, a sealing rubber ring is provided at the opening of the top cooling air duct, and a sealing rubber ring is provided at the opening of the connecting air duct.

4. The energy storage system according to claim 1, characterized in that: The cooling fans correspond to four battery units.

5. The energy storage system according to claim 1, characterized in that: The battery cluster includes a plurality of the battery cells and a plurality of temperature sensors. The temperature sensors correspond to the battery cells one by one and are arranged on the battery cells. The temperature sensors are connected to the control device.

6. The energy storage system according to claim 1, characterized in that: Adjacent battery cells in the battery cluster are arranged at intervals.

7. The energy storage system according to claim 1, characterized in that: The energy storage system further comprises: a fire-fighting device; The fire-fighting device includes a fire-fighting device, a plurality of fire-fighting pipelines and a plurality of nozzles, the fire-fighting pipeline is connected to the fire-fighting device, the fire-fighting device and the fire-fighting pipeline are also connected to the control device, the fire-fighting pipeline is arranged on the side of the top cooling air duct and the side of the bottom cooling air duct, and is arranged along the length direction of the battery rack, and the nozzles are arranged on the fire-fighting pipeline at intervals; The control device is also used to control the start and stop of the fire extinguishing equipment, and control the conduction of the corresponding fire protection pipeline according to the location of the battery unit that has caught fire.

8. The energy storage system according to any one of claims 1 to 7, characterized in that: The energy storage system further includes: a box; The battery rack, the cooling device, the battery cluster and the control device are all arranged in the box.

9. An energy storage cooling method, characterized in that: The method is performed by the energy storage system according to any one of claims 1 to 8, wherein the energy storage system comprises a cooling fan and a refrigeration device; and the energy storage cooling method comprises: Acquire the temperature of the battery cell with the highest temperature and the temperature of the battery cell with the lowest temperature among the multiple battery cells corresponding to the cooling fan; Calculating a battery cell temperature difference according to the temperature of the battery cell with the highest temperature and the temperature of the battery cell with the lowest temperature; If the battery cell temperature difference is greater than or equal to a preset temperature difference and / or the temperature of the battery cell with the highest temperature is greater than or equal to a preset battery cell temperature, determining whether the speed of the cooling fan reaches a maximum speed; If the speed of the cooling fan reaches the maximum speed, the refrigeration device is controlled to reduce the temperature of the cooling air generated by the refrigeration device, and the temperature of the battery cell with the highest temperature and the temperature of the battery cell with the lowest temperature are re-obtained after a preset delay; If the speed of the cooling fan does not reach the maximum speed, the cooling fan is controlled to increase the speed, and the temperature of the battery cell with the highest temperature and the temperature of the battery cell with the lowest temperature are re-obtained after a preset delay; If the battery cell temperature difference is less than the preset temperature difference and the temperature of the battery cell with the highest temperature is less than the preset battery cell temperature, the cooling fan is controlled to rotate at an initial speed and the temperature of the battery cell with the highest temperature and the temperature of the battery cell with the lowest temperature are re-obtained.

10. The energy storage cooling method according to claim 9, characterized in that: Before obtaining the temperature of the battery cell with the highest temperature and the temperature of the battery cell with the lowest temperature among the plurality of battery cells corresponding to the cooling fan, the method further includes: Acquire the current state of the energy storage system and the temperature of the environment in which the energy storage system is located; If the current state of the energy storage system is running, determining whether the temperature of the environment in which the energy storage system is located reaches a preset ambient temperature; If the temperature of the environment in which the energy storage system is located reaches a preset ambient temperature, the cooling fan and the refrigeration device are started, and the temperature of the battery cell with the highest temperature and the temperature of the battery cell with the lowest temperature among the multiple battery cells corresponding to the cooling fan are obtained; If the temperature of the environment in which the energy storage system is located does not reach the preset ambient temperature, re-obtaining the temperature of the environment in which the energy storage system is located; If the current state of the energy storage system is standby, the current state of the energy storage system is re-acquired.

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