Device and method for recycling waste heat of battery energy storage system

Abstract

The invention relates to a waste heat recycling device and method for a battery energy storage system, and belongs to the technical field of waste heat utilization. The recycling device comprises a battery energy storage system and a lithium bromide refrigerating device, and the lithium bromide refrigerating device and the battery energy storage system conduct heat convection through a flow blocking structure. A large amount of waste heat generated in the electrochemical reaction process in the battery energy storage system forms a cold source through the lithium bromide refrigeration system, the cold source can be used for cooling the battery energy storage system at the same time, the cooling power requirement of an existing battery energy storage system is lowered, the utilization rate of the electrochemical reaction waste heat in the battery energy storage system is increased, and the energy consumption of the battery energy storage system is reduced. And the energy efficiency of the battery energy storage system is improved. In addition, compared with air cooling, the device can be installed in a container, equipment faults are reduced, and the later operation and maintenance workload is relatively small.

Description

Technical Field

[0001] This invention belongs to the field of waste heat utilization technology, and specifically relates to a device and method for reusing waste heat from a battery energy storage system. Background Technology

[0002] With the continuous development of lithium-ion battery energy storage technology and its integration, more and more new lithium-ion battery energy storage power stations are being built. Lithium-ion battery energy storage units have advantages over traditional power generation, such as fast response speed and short start-up and shutdown time. However, they generate a certain amount of heat during charging and discharging, which causes the battery temperature to rise. The increased temperature affects many of the battery's operating characteristics, such as internal resistance, charging and discharging efficiency, and battery life. The battery thermal effect also affects the overall performance and cycle life of the energy storage system.

[0003] To ensure stable operation of lithium-ion batteries at suitable temperatures, current lithium-ion battery energy storage systems are equipped with auxiliary cooling devices such as air cooling or liquid cooling. These auxiliary devices themselves consume significant energy during operation, and the heat generated during the charging and discharging of lithium batteries is not effectively utilized, reducing the system's energy efficiency. Air cooling uses low-temperature air as a medium, utilizing natural wind or a fan to generate heat convection between the air and the battery cells, thereby lowering the battery temperature. While air cooling has a simple structure, it generates substantial self-consumption of electricity, resulting in low system energy conversion efficiency. Furthermore, the rotating fan components of air-cooled products are more prone to failure, leading to a greater workload for subsequent maintenance. Summary of the Invention

[0004] To address the aforementioned problems, this invention provides a device and method for utilizing waste heat from a battery energy storage system. This device can utilize the heat generated during the charging and discharging process of the battery energy storage system to cool the system, thereby improving the system's energy utilization efficiency, reducing the system's operating temperature, and ensuring the system's safety and lifespan.

[0005] The first objective of this invention is to provide a waste heat recovery device for a battery energy storage system, comprising: a battery energy storage system and a lithium bromide refrigeration device, wherein the lithium bromide refrigeration device and the battery energy storage system exchange heat through a flow-blocking structure.

[0006] Furthermore, the flow-blocking structure is a rib or a filter screen.

[0007] Furthermore, the lithium bromide refrigeration device includes a generator, a condenser, a throttling valve, an evaporator, a solution pump, and a generator;

[0008] One end of the generator is connected to a solution pump, and the other end of the generator is connected to a condenser. The end of the condenser away from the generator is connected to a throttling valve. The end of the throttling valve away from the condenser is connected to an evaporator. The end of the evaporator away from the throttling valve is connected to the absorber. The end of the absorber away from the evaporator is connected to the solution pump. The generator and the absorber are connected by a pipeline.

[0009] Furthermore, the battery energy storage system is heated by convective heat exchange with the generator through a flow-blocking structure.

[0010] Furthermore, the battery energy storage system uses a flow-blocking structure to exchange heat and provide cooling via convective heat exchange with the evaporator.

[0011] Furthermore, the battery energy storage system includes a lithium-ion battery energy storage system, a flow battery energy storage system, and a sodium-ion battery energy storage system.

[0012] The second objective of this invention is to provide a method for reusing waste heat from a battery energy storage system, implemented by the aforementioned waste heat reuse device for a battery energy storage system, comprising:

[0013] The battery energy storage system and the lithium bromide refrigeration device are heated by convective heat exchange through a flow-blocking structure. The heat generated by the battery energy storage system provides energy for the concentration of the lithium bromide solution in the lithium bromide refrigeration device.

[0014] Furthermore, the battery energy storage system and the generator in the lithium bromide refrigeration device exchange heat through a flow-blocking structure, and the battery energy storage system is cooled by the cooling water in the generator.

[0015] The beneficial effects of this invention are:

[0016] This invention provides a waste heat utilization device and method for battery energy storage systems. The device utilizes a lithium bromide refrigeration system to generate a large amount of waste heat during the electrochemical reaction process in the battery energy storage system, forming a cold source. This cold source can also be used to cool the battery energy storage system, reducing the power demand for cooling in existing battery energy storage systems, improving the utilization of waste heat from electrochemical reactions, and increasing the energy efficiency of the battery energy storage system. Furthermore, compared to air cooling, this device can be installed inside a container, reducing equipment failures and minimizing subsequent maintenance workload.

[0017] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures pointed out in the description, claims and drawings. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 A schematic diagram of a waste heat recovery device for a battery energy storage system according to an embodiment of the present invention is shown.

[0020] Figure 2 A schematic diagram of a battery energy storage system according to an embodiment of the present invention is shown;

[0021] In the picture:

[0022] 10. Battery energy storage system; 20. Generator; 21. Condenser; 22. Throttling valve; 23. Evaporator; 24. Solution pump; 25. Absorber; 30. Flow choke structure. Detailed Implementation

[0023] 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.

[0024] like Figure 1 As shown, a battery energy storage system waste heat recycling device according to an embodiment of the present invention includes: a battery energy storage system 10 and a lithium bromide refrigeration device, wherein the lithium bromide refrigeration device and the battery energy storage system 10 exchange heat through a flow-blocking structure 30.

[0025] In some embodiments of the present invention, the flow-blocking structure 30 is a rib. In addition to ribs, the flow-blocking structure 30 may also use other components that can play a blocking role, such as a filter screen.

[0026] In some embodiments of the present invention, the lithium bromide refrigeration device includes a generator 20, a condenser 21, a throttling valve 22, an evaporator 23, a solution pump 24, and an absorber 25;

[0027] One end of the generator 20 is connected to a solution pump 24, and the other end is connected to a condenser 21. The end of the condenser 21 furthest from the generator 20 is connected to a throttling valve 22. The end of the throttling valve 22 furthest from the condenser 21 is connected to an evaporator 23. The end of the evaporator 23 furthest from the throttling valve 22 is connected to an absorber 25. The end of the absorber 25 furthest from the evaporator 23 is connected to the solution pump 24. The generator 20 and the absorber 25 are connected by a pipe equipped with a valve. A dilute lithium bromide solution flows from the generator 20 to the absorber. Figure 1 As shown by the dashed arrow, the refrigerant circulates in a closed loop consisting of generator 20, condenser 21, expansion valve 22, evaporator 23, solution pump 24, and absorber 25. Figure 1 As indicated by the solid arrow in the figure, in this example of the invention, the refrigerant is water.

[0028] In some embodiments of the present invention, the battery energy storage system 10 exchanges heat with the generator 20 via a flow-blocking structure 30.

[0029] In some embodiments of the present invention, the battery energy storage system 10 exchanges heat with the evaporator 23 via a flow-blocking structure 30.

[0030] In some embodiments of the present invention, the battery energy storage system 10 includes a lithium-ion battery energy storage system, a flow battery energy storage system, and a sodium-ion battery energy storage system.

[0031] A method for recycling waste heat from a battery energy storage system according to an embodiment of the present invention is implemented by the waste heat recycling device for a battery energy storage system described in the above embodiment, comprising:

[0032] The battery energy storage system 10 and the lithium bromide refrigeration device exchange heat through convection via the flow-blocking structure 30. The heat generated by the battery energy storage system 10 provides energy for the concentration of the lithium bromide solution in the lithium bromide refrigeration device.

[0033] In some embodiments of the present invention, the battery energy storage system 10 and the generator 20 in the lithium bromide refrigeration device are heated by convective heat exchange through the flow-blocking structure 30, and the heat generated by the battery energy storage system 10 provides energy for the concentration of the lithium bromide solution in the generator 20.

[0034] In some embodiments of the present invention, the battery energy storage system 10 and the evaporator 23 in the lithium bromide refrigeration device exchange heat through a flow-blocking structure 30, and the battery energy storage system 10 is cooled by the cooling water in the evaporator 23.

[0035] In some embodiments of the present invention, such as Figure 2A schematic diagram of the battery energy storage system is provided. The battery energy storage system 10 consists of several battery modules, a water medium, and a waterproof insulating box. It also includes an inlet and an outlet for the water medium, which are positioned opposite each other on the periphery of the waterproof insulating box. Each battery module is encased in a waterproof and thermally conductive film, immersing each module in a water-based liquid environment. All battery modules and the water medium are encapsulated within the waterproof insulating box. During operation, the heat dissipated by each battery module is transferred to the water medium through the waterproof and thermally conductive film. The water medium is circulated by a circulation pump to ensure uniform temperature. The heat from the water medium inside the waterproof insulating box diffuses to the surface of the box and undergoes convective heat exchange with the generator 20 in the lithium bromide refrigeration device, causing the temperature of the dilute lithium bromide solution inside the generator 20 to rise and generate water vapor. At this time, the dilute lithium bromide solution becomes a concentrated lithium bromide solution due to water evaporation and enters the absorber 25 for storage. The generated water vapor passes through the condenser 21, where its temperature decreases and it becomes condensate (here, the condenser 21 also achieves the effect of internal water vapor condensation through convection heat exchange with the external natural environment). At this time, the condensate is in a low temperature and high pressure state. Then, it passes through the throttling valve 22 (the function of the throttling valve 22 is to reduce the fluid pressure) and becomes low temperature and low pressure cooling water (also called refrigerant water). At this time, the cooling water enters the evaporator 23 to exchange heat and cool the object being cooled (i.e., the battery energy storage system 10), thereby reducing the temperature of the object being cooled (i.e., the battery energy storage system 10).

[0036] In the evaporator 23, the cooling water temperature rises continuously after heat exchange. The heated cooling water flows into the absorber 25 and is absorbed by the concentrated lithium bromide solution. The concentrated lithium bromide solution then becomes a dilute lithium bromide solution and is then pumped by the solution pump 24 to the generator 20 to continue the next refrigeration cycle.

[0037] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A battery energy storage system waste heat reutilization device, characterized in that, The application relates to a battery energy storage system (10) and a lithium bromide refrigerating device, wherein the lithium bromide refrigerating device and the battery energy storage system (10) are in counterflow heat exchange through a flow resistance structure (30). The flow resistance structure (30) is a rib or a filter screen.

2. The battery energy storage system waste heat reutilization device of claim 1, wherein, The lithium bromide refrigerating device comprises a generator (20), a condenser (21), a throttle valve (22), an evaporator (23), a solution pump (24) and an absorber (25).

3. The battery energy storage system waste heat reutilization device of claim 1, wherein, One end of the generator (20) is connected with the solution pump (24), the other end is connected with the condenser (21), one end of the condenser (21) away from the generator (20) is connected with the throttle valve (22), one end of the throttle valve (22) away from the condenser (21) is connected with the evaporator (23), one end of the evaporator (23) away from the throttle valve (22) is connected with the absorber (25), one end of the absorber (25) away from the evaporator (23) is connected with the solution pump (24), and the generator (20) and the absorber (25) are communicated through a pipeline. The battery energy storage system (10) is in counterflow heat exchange with the generator (20) through the flow resistance structure (30) to be heated.

4. The battery energy storage system waste heat reutilization device of claim 3, wherein, The battery energy storage system (10) is in counterflow heat exchange with the evaporator (23) through the flow resistance structure (30) to be refrigerated.

5. The battery energy storage system waste heat reutilization device of claim 3, wherein, The battery energy storage system (10) comprises a lithium ion battery energy storage system, a flow battery energy storage system and a sodium ion battery energy storage system.

6. The battery energy storage system waste heat reutilization device of any one of claims 1-5, wherein, The application is realized by the battery energy storage system waste heat recycling device in any one of claims 1-6, and comprises:

7. A method for reusing waste heat of a battery energy storage system, characterized in that, The battery energy storage system (10) and the lithium bromide refrigerating device are in counterflow heat exchange through the flow resistance structure (30), and heat generated by the battery energy storage system (10) provides energy for concentration of lithium bromide solution in the lithium bromide refrigerating device. The battery energy storage system (10) and the generator (20) in the lithium bromide refrigerating device are in counterflow heat exchange through the flow resistance structure (30) to be refrigerated, and the battery energy storage system (20) is cooled by cooling water in the generator (20).

8. The method of claim 7, wherein the battery energy storage system is a lithium-ion battery energy storage system. ​

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