Flow battery waste heat recovery and energy storage system

Abstract

The utility model discloses a redox flow battery waste heat recovery and energy storage system, which belongs to the technical field of redox flow batteries and comprises a redox flow battery energy storage module and an air pressure nitrogen production waste heat recovery module, and the air pressure nitrogen production waste heat recovery module comprises a nitrogen production unit, an air compressor unit and an air pressure waste heat recovery hot water unit which are sequentially connected. The air compressor unit is used for providing compressed air for the nitrogen making unit, the nitrogen making unit is used for making the compressed air into nitrogen and conveying the nitrogen into the flow battery energy storage module to achieve gas purging and nitrogen sealing of the flow battery energy storage module, and the air compression waste heat recovery hot water unit is used for recovering waste heat generated by the air compressor unit. Therefore, the electrolyte temperature of the flow battery energy storage module is increased. The flow battery energy storage module and the air pressure nitrogen production waste heat recovery module are reasonably arranged, and waste heat generated by high-temperature oil gas of an air compressor is used as an internal heat source to adjust the temperature of electrolyte, so that the heat cycle efficiency is improved, and the charge and discharge efficiency of the flow battery energy storage system is improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of flow batteries, and particularly relates to a flow battery waste heat recovery energy storage system. Background Technique

[0002] As a new energy storage technology with advantages of large-scale energy storage, long life and high safety, flow batteries are gradually showing great potential for commercial applications globally. The temperature of the flow battery electrolyte has a significant impact on the charge and discharge performance of the battery. Within an appropriate temperature range, the conductivity and ion migration speed of the electrolyte are relatively high, which is beneficial to the efficient charge and discharge process of the battery. If the temperature is too high or too low, it may lead to a decline in the performance of the electrolyte, thus affecting the charge and discharge efficiency of the battery. Therefore, maintaining an appropriate electrolyte temperature can slow down the capacity decay of the battery and improve the economy of the system.

[0003] As a temperature regulation method, the thermal management system generally introduces high-temperature external heat sources such as steam and hot water, and adjusts the temperature of the electrolyte through the heat exchange amount of the heat exchanger. However, the introduction of external heat sources will further increase the energy consumption of the auxiliary system of the energy storage system, reducing the efficiency of the flow battery charge and discharge system. In the flow battery energy storage system, an air compressor nitrogen generator is used to generate nitrogen as a protective gas to prevent the oxidation of the electrolyte, and nitrogen purging is used to maintain the nitrogen seal state of the system and tail gas absorption, improving the stability and safety of the system. However, a large amount of heat is generated when the air compressor nitrogen generator unit produces nitrogen, and this part of heat will be directly discharged into the environment, resulting in great heat loss. Therefore, in order to achieve the purpose of waste heat recovery, energy conservation and emission reduction, and saving floor space, the utility model proposes a flow battery waste heat recovery energy storage system, which recovers the waste heat generated by the air compressor nitrogen generator through this system and utilizes this part of heat for temperature regulation of the electrolyte, improving the thermal cycle efficiency and increasing the charge and discharge efficiency of the flow battery energy storage system. Summary of the Utility Model

[0004] The main purpose of the utility model is to provide a flow battery waste heat recovery energy storage system, which greatly reduces heat dissipation loss, improves the thermal cycle efficiency, and increases the charge and discharge efficiency of the flow energy storage system by reasonably arranging the flow battery energy storage module and the air compressor waste heat recovery module, and using the waste heat generated by the high-temperature oil and gas of the air compressor as an internal heat source to adjust the temperature of the electrolyte.

[0005] To achieve the above purpose, the utility model provides a flow battery waste heat recovery energy storage system, which includes a flow battery energy storage module and an air compressor waste heat recovery module. The air compressor waste heat recovery module includes a nitrogen generator unit, an air compressor unit and an air compressor waste heat recovery hot water unit connected in sequence;

[0006] The air compressor unit is used to supply compressed air to the nitrogen generation unit. The nitrogen generation unit is used to produce nitrogen from the compressed air and to transport the nitrogen to the flow battery energy storage module to achieve gas purging and nitrogen sealing of the flow battery energy storage module. The air compressor waste heat recovery hot water unit is used to recover the waste heat generated by the air compressor unit to maintain the electrolyte temperature of the flow battery energy storage module.

[0007] Further, the flow battery energy storage module includes a positive electrolyte storage tank, a negative electrolyte storage tank, a positive pump, a negative pump, and a battery stack. The electrolytes in the positive electrolyte storage tank and the negative electrolyte storage tank enter the positive and negative electrodes of the battery stack via the positive pump and the negative pump, and then flow out from the positive and negative electrodes of the battery stack and return to the positive electrolyte storage tank and the negative electrolyte storage tank to form an electrolyte circulation.

[0008] Further, the air compressor waste heat recovery hot water unit includes a return water preheater, a heat preservation water tank, a hot water heater, a positive and negative heat exchanger, and a hot water circulation pump.

[0009] One end of the return water preheater and the hot water heater is connected to the air compressor unit, respectively, for recovering the waste heat of the compressed air and the high-temperature lubricating oil in the air compressor unit.

[0010] One end of the return water preheater and the hot water heater is connected to the heat preservation water tank, for storing the waste heat recovered from the air compressor unit in the heat preservation water tank.

[0011] The inlet end of the positive and negative heat exchanger is connected to the heat preservation water tank through a hot water supply pipeline, and the outlet end of the positive and negative heat exchanger is connected to the hot water return pipeline of the return water preheater. The positive and negative heat exchanger is arranged on the pipeline between the positive and negative pumps and the battery stack for adjusting the temperature of the electrolyte. The hot water circulation pump is arranged on the hot water supply pipeline between the heat preservation water tank and the positive and negative heat exchanger.

[0012] Further, the air compressor unit includes a compressor, an oil and gas separator, an oil cooler, and an air cooler.

[0013] The input end of the oil and gas separator is connected to the compressor, for separating the compressed air and the lost lubricating oil generated by the compressor. The gas output end and the oil output end of the oil and gas separator are respectively connected to the return water preheater and the hot water heater.

[0014] The input end of the oil cooler is connected to the hot water heater, and the output end of the oil cooler is connected to the compressor.

[0015] The input end of the air cooler is communicated with the return water preheater, and the output end of the air cooler is communicated with the nitrogen generation unit.

[0016] Further, on the hot water supply pipeline and at the rear end of the hot water circulation pump, a water supply temperature control regulating valve is provided;

[0017] A branch pipeline is provided on the pipeline between the hot water circulation pump and the water supply temperature control regulating valve. One end of the branch pipeline is connected to the heat preservation water tank, and the other end of the branch pipeline is connected to the hot water supply pipeline. And a water tank temperature control regulating valve is provided on the branch pipeline.

[0018] Further, the opening degrees of the water supply temperature control regulating valve and the water tank temperature control regulating valve are automatically controlled by interlocking protection with the electrolyte temperature.

[0019] Further, the nitrogen outlet of the nitrogen generation unit is communicated with the positive electrode liquid storage tank, and an air communication pipeline is provided between the positive electrode liquid storage tank and the negative electrode liquid storage tank for transporting nitrogen.

[0020] Further, the liquid flow battery waste heat recovery energy storage system further includes an alkali absorption tower. Breather valves are installed on the tops of the positive electrode liquid storage tank and the negative electrode liquid storage tank, and the breather valves are communicated with the alkali absorption tower through pipelines.

[0021] Further, the outside of the heat preservation water tank adopts double-layer heat preservation. The inner layer adopts a vacuum interlayer, and the outer layer is arranged with heat-insulating and heat-preserving materials.

[0022] Further, the body of the heat preservation water tank is provided with a solar heat collection system.

[0023] Compared with the prior art, the utility model has the following beneficial effects:

[0024] 1. Based on the high-temperature lubricating oil and high-temperature compressed air generated by the air compressor unit as heat sources, through the air compressor waste heat recovery hot water unit, the heat is exchanged twice by entering the return water preheater and the hot water heater to become hot water. The hot water enters the positive and negative heat exchangers, and the hot water flow is automatically adjusted by the temperature control regulating valve to maintain the temperature range of the electrolyte. At the same time, considering the intermittent operation strategy of the air compressor unit and the nitrogen generation unit, the heat preservation water tank is used as a temporary heat storage heat source. To extend the heat storage and heat preservation duration, the body of the heat preservation tank is also provided with a solar heat collection system to ensure a relatively stable hot water circulation after the air compressor unit and the nitrogen generation unit are temporarily shut down. In addition, the air compressor unit provides compressed air for the nitrogen generation unit to produce nitrogen for purging and nitrogen sealing of the liquid flow battery energy storage system, and a set of efficient waste heat recovery automatic thermal management system suitable for the liquid flow battery energy storage module is successfully constructed.

[0025] 2. The utility model utilizes the high-temperature oil and gas inside the compressor as a heat source, reduces the cancellation of heat and cold, improves the thermal cycle efficiency, realizes the reuse of the thermal cycle, and improves the overall utilization efficiency of the liquid flow battery energy storage system.

[0026] 3. By introducing an air compressor unit, a nitrogen generation unit and an air compressor waste heat recovery hot water unit into the liquid flow battery energy storage module, the utility model realizes the dual functions of preventing the oxidation of the electrolyte and maintaining the temperature of the electrolyte, achieves the effect of energy conservation and emission reduction, and forms a highly modular liquid flow battery waste heat recovery energy storage system. The integrated layout of this system saves floor space, lays a foundation for the subsequent large-capacity multi-megawatt liquid flow battery energy storage system, and has significant popularization and application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The schematic diagrams in the specification, which form a part of this application, are used to provide a further understanding of the utility model. The schematic embodiments and descriptions of the utility model are used to explain the utility model and do not constitute an improper limitation to the utility model. In the drawings:

[0028] Figure 1 The structural schematic diagram of the liquid flow battery waste heat recovery energy storage system in an embodiment of the utility model is shown;

[0029] Figure 2 The structural schematic diagram of the air compression and nitrogen generation waste heat recovery module in an embodiment of the utility model is shown.

[0030] Among them, the above-mentioned drawings include the following reference numerals: 1. Positive electrode liquid storage tank, 2. Negative electrode liquid storage tank, 3. Positive electrode pump, 4. Negative electrode pump, 5. Battery stack, 6. Breather valve, 10. Nitrogen generation unit, 20. Air compressor unit, 30. Air compressor waste heat recovery hot water unit, 21. Compressor, 22. Oil-gas separator, 23. Oil cooler, 24. Gas cooler, 31. Return water preheater, 32. Heat preservation water tank, 33. Hot water heater, 34. Positive and negative electrode heat exchanger, 35. Hot water circulation pump, 36. Water supply temperature control regulating valve, 37. Water tank temperature control regulating valve, 38. Solar heat collection system. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0031] In order to make the objectives, technical solutions and advantages of the embodiments of the utility model clearer, the technical solutions in the embodiments of the utility model will be clearly and completely described below with reference to the drawings in the embodiments of the utility model. Obviously, the described embodiments are some but not all of the embodiments of the utility model. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the utility model without creative efforts shall fall within the protection scope of the utility model.

[0032] To achieve the above object, an embodiment of the present utility model provides a waste heat recovery energy storage system for a flow battery, as Figure 1 shown, which includes a flow battery energy storage module and an air compression nitrogen production waste heat recovery module. The air compression nitrogen production waste heat recovery module includes a nitrogen production unit 10, an air compression unit 20, and an air compression waste heat recovery hot water unit 30 that are connected in sequence;

[0033] The air compression unit 20 is used to provide compressed air to the nitrogen production unit 10. The nitrogen production unit 10 is used to make nitrogen from the compressed air and is used to transport the nitrogen to the flow battery energy storage module to realize gas purging and nitrogen sealing of the flow battery energy storage module. The air compression waste heat recovery hot water unit 30 is used to recover the waste heat generated by the air compression unit 20 to heat the electrolyte temperature of the flow battery energy storage module.

[0034] In a specific embodiment of the present utility model, the flow battery energy storage module includes a positive electrode liquid storage tank 1, a negative electrode liquid storage tank 2, a positive electrode pump 3, a negative electrode pump 4, and a battery stack 5. The electrolytes in the positive electrode liquid storage tank 1 and the negative electrode liquid storage tank 2 enter the positive electrode and the negative electrode of the battery stack 5 through the positive electrode pump 3 and the negative electrode pump 4, and then flow out from the positive electrode and the negative electrode of the battery stack 5 and return to the positive electrode liquid storage tank 1 and the negative electrode liquid storage tank 2 to form an electrolyte circulation.

[0035] In a specific embodiment of the present utility model, as Figure 2 shown, the air compression waste heat recovery hot water unit 30 includes a return water preheater 31, a heat preservation water tank 32, a hot water heater 33, a positive and negative heat exchanger 34, and a hot water circulation pump 35. One ends of the return water preheater 31 and the hot water heater 33 are connected to the air compression unit 20, and are respectively used to recover the compressed air waste heat and the high-temperature lubricating oil waste heat in the air compression unit 20. One ends of the return water preheater 31 and the hot water heater 33 are connected to the heat preservation water tank 32, and are used to store the waste heat recovered from the air compression unit 20 in the heat preservation water tank 32. The inlet end of the positive and negative heat exchanger 34 is connected to the heat preservation water tank 32 through a hot water supply pipeline, and the outlet end of the positive and negative heat exchanger 34 is connected to the return water preheater 31 through a hot water return pipeline. The positive and negative heat exchanger 34 is arranged on the pipeline between the positive and negative pumps and the battery stack 5 and is used to adjust the temperature of the electrolyte. The hot water circulation pump 35 is arranged on the hot water supply pipeline between the heat preservation water tank 32 and the positive and negative heat exchanger 34.

[0036] In a specific embodiment of the present utility model, as Figure 2As shown, the air compressor unit 20 includes a compressor 21, an oil-gas separator 22, an oil cooler 23, and an air cooler 24; the input end of the oil-gas separator 22 is connected to the compressor 21, and is used for separating the compressed air generated by the compressor 21 and the lost high-temperature lubricating oil; the gas output end and the oil output end of the oil-gas separator 22 are respectively communicated with the return water preheater 31 and the hot water heater 33; the input end of the oil cooler 23 is communicated with the hot water heater 33, and the output end of the oil cooler 23 is communicated with the compressor 21; the input end of the air cooler 24 is communicated with the return water preheater 31, and the output end of the air cooler 24 is communicated with the nitrogen generation unit 10.

[0037] During the long-term continuous operation of the compressed air system, high-temperature and high-pressure gases and additional frictional heat generated by the high-speed rotation of the screw are mixed with the lubricating oil of the air compressor to form a high-temperature oil-gas mixture and discharged. The heat of the high-temperature oil-gas mixture is about 25% of the input power of the air compressor. Finally, through the cooling system inside the air compressor, it is directly dissipated and discharged, causing great heat dissipation loss. In order to utilize this part of the heat, after the high-temperature oil-gas mixture passes through the oil-gas separator 22, compressed air and high-temperature oil are obtained. Among them, the compressed air enters the return water preheater 31 through the air inlet pipeline. The heat in the compressed air can be used to heat the low-temperature return water (i.e., the return water output by the positive and negative heat exchangers 34) entering the return water preheater 31, and then the heated return water is transported to the heat preservation water tank 32 for heat preservation storage. The compressed air is then discharged from the return water preheater 31, enters the nitrogen generation unit 10 through the air cooler 24, and nitrogen is produced. The lost high-temperature lubricating oil (80 - 120 °C) enters the hot water heater 33 of the air compressor waste heat recovery hot water unit 30 through the oil supply pipeline. The hot water heater 33 heats the temperature of the heat preservation water tank 32 to keep the hot water in the heat preservation water tank 32 at a certain temperature. The hot water in the heat preservation water tank 32 enters the positive and negative heat exchangers 34 by the hot water circulation pump 35 to adjust the electrolyte temperature.

[0038] In some alternative embodiments, the positive and negative heat exchangers 34 are not limited to spiral plate heat exchangers, plate heat exchangers, shell-and-tube heat exchangers, and heat pipe heat exchangers, and need to be comprehensively considered and selected according to specific working conditions, heat transfer efficiency, and economy.

[0039] In a specific embodiment of the present invention, on the hot water supply pipeline, and at the rear end of the hot water circulation pump 35, a water supply temperature control regulating valve 36 is provided; on the pipeline between the hot water circulation pump 35 and the water supply temperature control regulating valve 36, a branch pipeline is provided. One end of the branch pipeline is connected to the heat preservation water tank 32, the other end of the branch pipeline is connected to the hot water supply pipeline, and a water tank temperature control regulating valve 37 is provided on the branch pipeline.

[0040] When the nitrogen generation unit 10 and the air compressor unit 20 are operating and the electrolyte temperature is relatively low, the hot water in the heat preservation water tank 32 can reduce the opening degree of the water tank temperature control regulating valve 37, and at the same time increase the opening degree of the water supply temperature control regulating valve 36. A small amount of hot water in the heat preservation water tank 32 directly returns to the heat preservation water tank 32 through the hot water circulation pump 35 and the water tank temperature control regulating valve 37 to realize the self-circulation of the hot water in the heat preservation water tank 32. Most of the hot water enters the positive and negative electrode heat exchangers 34 through the hot water circulation pump 35 to quickly increase the temperature of the electrolyte. On the contrary, when the temperature of the electrolyte is relatively high, it is necessary to increase the opening degree of the water tank temperature control regulating valve 37 and reduce the opening degree of the water supply temperature control regulating valve 36, thereby reducing the heat supplied to the water, so as to maintain the electrolyte within a reasonable operating temperature range.

[0041] Further, the opening degrees of the water supply temperature control regulating valve 36 and the water tank temperature control regulating valve 37 are automatically controlled in interlock protection with the electrolyte temperature. Through the temperature limit value of the electrolyte, the automatic adjustment of the water supply temperature control regulating valve 36 and the water tank temperature control regulating valve 37 is realized, forming an efficient waste heat recovery automatic thermal management system.

[0042] In a specific embodiment of the present invention, the nitrogen outlet of the nitrogen generation unit 10 is communicated with the positive electrode liquid storage tank 1, and an air communication pipeline is provided between the positive electrode liquid storage tank 1 and the negative electrode liquid storage tank 2 for transporting nitrogen.

[0043] The nitrogen generation unit 10 of the present invention utilizes the PSA pressure swing adsorption principle. Based on the large difference in the diffusion rates of oxygen and nitrogen on the carbon molecular sieve, a large amount of oxygen molecules are adsorbed by the carbon molecular sieve in a short time to achieve oxygen-nitrogen separation. Since hydrogen is generated at the negative electrode during the charging process of the flow battery stack, nitrogen is introduced into the positive and negative electrode electrolyte storage tanks, and the hydrogen and the acidic gas (hydrochloric acid) generated by the electrolyte can be discharged to the tail gas treatment system in a timely manner by means of nitrogen purging. In addition, as a protective gas, nitrogen can effectively prevent the oxidation of the electrolyte in the positive and negative electrode electrolyte storage tanks.

[0044] In a specific embodiment of the present invention, the flow battery waste heat recovery energy storage system further includes an alkali absorption tower. A breathing valve 6 is installed on the tops of the positive electrode liquid storage tank 1 and the negative electrode liquid storage tank 2, and the breathing valve 6 is communicated with the alkali absorption tower through a pipeline. In order to prevent the internal pressure of the positive and negative electrode liquid storage tanks from being too high, a breathing valve 6 is installed on their tops. When the pressure exceeds the design value, the breathing valve 6 opens, and the gas in the positive and negative electrode liquid storage tanks automatically discharges into the alkali absorption tower.

[0045] In a specific embodiment of the present invention, the body of the heat preservation water tank 32 is provided with a solar heat collection system 38 for circulating and heating the hot water in the heat preservation water tank 32.

[0046] To maintain the pressure range of the liquid flow battery storage tank, the nitrogen generation unit 10 and the air compressor unit 20 implement an intermittent operation strategy. When the nitrogen generation unit 10 and the air compressor unit 20 are shut down, the waste heat of the high-temperature oil and gas cannot be utilized. To solve the above problems, on the one hand, the present utility model uses the hot water in the heat preservation water tank 32 as a temporary high-temperature heat storage heat source, and the hot water capacity in the heat preservation water tank 32 needs to be reasonably designed according to the shutdown duration. In addition, a solar heat collection system 38 is arranged on the body of the heat preservation water tank 32. During sufficient sunlight hours, the hot water in the heat preservation water tank 32 is heated repeatedly through multiple cycles of the solar heat collection system 38, so that the hot water in the heat preservation water tank 32 is quickly heated. Further, the outside of the heat preservation water tank 32 adopts double-layer heat preservation, with a vacuum interlayer on the inner layer and adiabatic heat preservation materials arranged on the outer layer, reducing heat dissipation loss, prolonging the heat preservation time, and ensuring that the temperature of the electrolyte of the liquid flow battery energy storage module can be maintained after the nitrogen generation unit 10 and the air compressor unit 20 are temporarily shut down.

[0047] Embodiment

[0048] A liquid flow battery waste heat recovery energy storage system, as Figure 1 and Figure 2 shown, includes a liquid flow battery energy storage module and an air compression and nitrogen generation waste heat recovery module. The air compression and nitrogen generation waste heat recovery module includes a nitrogen generation unit 10, an air compressor unit 20, and an air compression waste heat recovery hot water unit 30 that are connected in sequence. The air compressor unit 20 is used to provide compressed air to the nitrogen generation unit 10. The nitrogen generation unit 10 is used to make nitrogen from the compressed air and is used to transport the nitrogen to the liquid flow battery energy storage module to realize gas purging and nitrogen sealing of the liquid flow battery energy storage module. The air compression waste heat recovery hot water unit 30 is used to recover the waste heat generated by the air compressor unit 20 to heat the electrolyte temperature of the liquid flow battery energy storage module.

[0049] Among them, the liquid flow battery energy storage module includes a positive electrode storage tank 1, a negative electrode storage tank 2, a positive electrode pump 3, a negative electrode pump 4, a battery stack 5, a breathing valve 6, and an alkali absorption tower. The electrolytes in the positive electrode storage tank 1 and the negative electrode storage tank 2 enter the positive electrode and the negative electrode of the battery stack 5 through the positive electrode pump 3 and the negative electrode pump 4, and then flow out from the positive electrode and the negative electrode of the battery stack 5 and return to the positive electrode storage tank 1 and the negative electrode storage tank 2 to form an electrolyte circulation. Breathing valves 6 are installed on the tops of the positive electrode storage tank 1 and the negative electrode storage tank 2, and the breathing valves 6 are connected to the alkali absorption tower through pipelines.

[0050] Among them, the nitrogen outlet of the nitrogen generation unit 10 is connected to the positive electrode storage tank 1, and a gas connection pipeline is provided between the positive electrode storage tank 1 and the negative electrode storage tank 2 for transporting nitrogen.

[0051] Among them, the air compressor unit 20 includes a compressor 21, an oil-gas separator 22, an oil cooler 23 and an air cooler 24; the air compressor waste heat recovery hot water unit includes a return water preheater 31, a heat preservation water tank 32, a hot water heater 33, a positive and negative heat exchanger 34, and a hot water circulation pump 35.

[0052] Specifically, the return water preheater 31 is provided with an air inlet, an air outlet, a hot water return port and a water outlet. The air inlet of the return water preheater 31 is communicated with the air outlet of the oil-gas separator 22, the air outlet of the return water preheater 31 is communicated with the air inlet of the air cooler 24, and the hot water return port of the return water preheater 31 is communicated with the outlet of the positive and negative heat exchanger 34; the water outlet of the return water preheater 31 is communicated with the heat preservation water tank 32, and is used for storing the compressed air waste heat in the air compressor unit 20 recovered in the heat preservation water tank 32.

[0053] The hot water heater 33 is provided with an oil supply port and an oil return port. The oil supply port and the oil return port of the hot water heater 33 are respectively communicated with the oil outlet of the oil-gas separator 32 and the inlet of the oil cooler 23; and the hot water heater 33 is arranged in the heat preservation water tank 32, and is used for heating the temperature of the heat preservation water tank 32, and is used for storing the high-temperature lubricating oil waste heat in the air compressor unit 20 recovered in the heat preservation water tank 32. Among them, the main body of the heat preservation water tank 32 is provided with a solar heat collection system 38 for circulating and heating the hot water in the heat preservation water tank 32, and the outside of the heat preservation water tank 32 adopts double-layer heat preservation, with a vacuum interlayer on the inner layer and heat insulation materials arranged on the outer layer.

[0054] The positive and negative heat exchanger 34 is arranged on the pipeline between the positive and negative pumps and the battery stack 5, and is used for regulating the temperature of the electrolyte; the hot water circulation pump 35 is arranged on the hot water supply pipeline between the heat preservation water tank 32 and the positive and negative heat exchanger 34. A water supply temperature control regulating valve 36 is arranged on the hot water supply pipeline and at the rear end of the hot water circulation pump 35. A branch pipeline is arranged on the pipeline between the hot water circulation pump 35 and the water supply temperature control regulating valve 36. One end of the branch pipeline is connected to the heat preservation water tank 32, the other end of the branch pipeline is connected to the hot water supply pipeline, and a water tank temperature control regulating valve 37 is arranged on the branch pipeline. The opening degrees of the water supply temperature control regulating valve 36 and the water tank temperature control regulating valve 37 are automatically controlled by interlocking protection with the electrolyte temperature.

[0055] The above embodiments only represent the implementation manners of the present invention, and the description thereof is relatively specific and detailed, but it should not be understood as a limitation to the scope of the patent of the present invention. The present invention can also be implemented in other specific manners or other specific forms without departing from the gist or essential features of the present invention. Therefore, the described implementation manners should be regarded as illustrative rather than restrictive in any aspect. The scope of the present invention should be defined by the appended claims, and any equivalent changes to the intention and scope of the claims should also be included within the scope of the present invention.

Claims

1. A liquid flow battery waste heat recovery energy storage system, characterized in that, It includes a flow battery energy storage module and an air compression nitrogen production waste heat recovery module. The air compression nitrogen production waste heat recovery module includes a nitrogen production unit (10), an air compressor unit (20), and an air compression waste heat recovery hot water unit (30) connected in sequence. The air compressor unit (20) is used to provide compressed air to the nitrogen production unit (10). The nitrogen production unit (10) is used to produce nitrogen from the compressed air and to transport the nitrogen to the flow battery energy storage module to achieve gas purging and nitrogen sealing of the flow battery energy storage module. The air compression waste heat recovery hot water unit (30) is used to recover the waste heat generated by the air compressor unit (20) to heat the electrolyte temperature of the flow battery energy storage module.

2. The flow battery waste heat recovery energy storage system according to claim 1, characterized in that The flow battery energy storage module includes a positive electrode liquid storage tank (1), a negative electrode liquid storage tank (2), a positive electrode pump (3), a negative electrode pump (4), and a battery stack (5). The electrolytes in the positive electrode liquid storage tank (1) and the negative electrode liquid storage tank (2) enter the positive electrode and the negative electrode of the battery stack (5) through the positive electrode pump (3) and the negative electrode pump (4), and then flow out from the positive electrode and the negative electrode of the battery stack (5) and return to the positive electrode liquid storage tank (1) and the negative electrode liquid storage tank (2) to form an electrolyte circulation.

3. The liquid flow battery waste heat recovery energy storage system according to claim 2, wherein, The air compression waste heat recovery hot water unit (30) includes a return water preheater (31), a heat preservation water tank (32), a hot water heater (33), a positive and negative heat exchanger (34), and a hot water circulation pump (35). One end of the return water preheater (31) and the hot water heater (33) is connected to the air compressor unit (20), which are respectively used to recover the waste heat of the compressed air and the high-temperature lubricating oil in the air compressor unit (20). One end of the return water preheater (31) and the hot water heater (33) is connected to the heat preservation water tank (32), which is used to store the waste heat recovered from the air compressor unit (20) in the heat preservation water tank (32). The inlet end of the positive and negative heat exchanger (34) is connected to the heat preservation water tank (32) through a hot water supply pipeline, and the outlet end of the positive and negative heat exchanger (34) is connected to the return water preheater (31) through a hot water return pipeline. The positive and negative heat exchanger (34) is arranged on the pipeline between the positive and negative pumps and the battery stack (5) and is used to adjust the temperature of the electrolyte. The hot water circulation pump (35) is arranged on the hot water supply pipeline between the heat preservation water tank (32) and the positive and negative heat exchanger (34).

4. The waste heat recovery energy storage system of the flow battery according to claim 3, wherein, The air compressor unit (20) includes a compressor (21), an oil-gas separator (22), an oil cooler (23), and an air cooler (24). The input end of the oil-gas separator (22) is connected to the compressor (21), which is used to separate the compressed air and the lost high-temperature lubricating oil generated by the compressor (21). The gas output end and the oil output end of the oil-gas separator (22) are respectively connected to the return water preheater (31) and the hot water heater (33). The input end of the oil cooler (23) is communicated with the hot water heater (33), and the output end of the oil cooler (23) is communicated with the compressor (21); The input end of the air cooler (24) is communicated with the return water preheater (31), and the output end of the air cooler (24) is communicated with the nitrogen generation unit (10).

5. The waste heat recovery energy storage system for a flow battery according to claim 3, characterized in that, On the hot water supply pipeline, a water supply temperature control regulating valve (36) is provided at the rear end of the hot water circulation pump (35); A branch pipeline is provided on the pipeline between the hot water circulation pump (35) and the water supply temperature control regulating valve (36). One end of the branch pipeline is connected to the heat preservation water tank (32), and the other end of the branch pipeline is connected to the hot water supply pipeline. A water tank temperature control regulating valve (37) is provided on the branch pipeline.

6. The flow battery waste heat recovery energy storage system according to claim 5, characterized in that, The opening degrees of the water supply temperature control regulating valve (36) and the water tank temperature control regulating valve (37) are automatically controlled by interlocking protection with the electrolyte temperature.

7. The liquid flow battery waste heat recovery energy storage system according to claim 2, wherein The nitrogen outlet of the nitrogen generation unit (10) is communicated with the positive electrode liquid storage tank (1), and an air communication pipeline is provided between the positive electrode liquid storage tank (1) and the negative electrode liquid storage tank (2) for transporting nitrogen.

8. The waste heat recovery energy storage system for a flow battery according to claim 2, wherein The liquid flow battery waste heat recovery energy storage system further includes an alkali absorption tower. A breathing valve (6) is installed on the tops of the positive electrode liquid storage tank (1) and the negative electrode liquid storage tank (2), and the breathing valve (6) is communicated with the alkali absorption tower through a pipeline.

9. The liquid flow battery waste heat recovery energy storage system according to claim 3, wherein, The body of the heat preservation water tank (32) is provided with a solar heat collection system (38) for circulating and heating the hot water in the heat preservation water tank (32).

10. The liquid flow battery waste heat recovery energy storage system according to claim 3, characterized in that, The outside of the heat preservation water tank (32) is double-layer heat-insulated. The inner layer is a vacuum interlayer, and the outer layer is arranged with heat-insulating materials.

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