Condensate water recovery and exhaust integrated device and liquid flow battery energy storage system

Abstract

A condensate water recovery and exhaust integrated device and a liquid flow battery energy storage system, the condensate water recovery and exhaust integrated device comprising a first pipeline, a condensate water recovery device and a water seal device, the first pipeline being connected with the inlet of the condensate water recovery device, the outlet of the condensate water recovery device being connected with the inlet of a three-way joint, two outlets of the three-way joint being connected with a second pipeline and a third pipeline respectively, the second pipeline being connected with the inlet of the water seal device, an exhaust valve being installed on the third pipeline, a check valve being installed on the second pipeline, and a pressure sensor for monitoring the pressure in the water seal device being arranged in the water seal device; the battery energy storage system comprising a nitrogen making unit, an electrolyte storage tank and the condensate water recovery and exhaust integrated device. The device can effectively prevent the crystallization phenomenon of the electrolyte caused by water evaporation, avoid the blockage of the battery stack, reduce the maintenance cost, prolong the service life of the equipment, improve the overall operation efficiency of the system, and help optimize the space layout of the storage tank.

Description

Technical Field

[0001] This utility model relates to the field of flow battery energy storage technology, and in particular to an integrated device for condensate recovery and exhaust, and a flow battery energy storage system. Background Technology

[0002] Flow battery energy storage systems are a novel electrochemical energy storage technology, primarily composed of core components such as a battery stack, electrolyte tank, circulating pump, piping system, thermal management system, electronic control system, power conversion unit, and safety and auxiliary systems. During charging, the circulating pump propels the positive and negative electrolytes through the battery stack. The positive electrolyte undergoes oxidation at the positive electrode, while the negative electrolyte undergoes reduction at the negative electrode, converting electrical energy into chemical energy and storing it in the electrolyte. During discharging, the electrolyte continues to flow; the positive electrolyte undergoes reduction at the positive electrode, and the negative electrolyte undergoes oxidation at the negative electrode, releasing chemical energy and converting it into electrical energy output.

[0003] Currently, flow battery energy storage systems typically employ independent water-sealing and nitrogen-sealing systems for gas management, resulting in complex system structures, large space requirements, and high maintenance costs. For batteries such as vanadium redox flow batteries, due to their weak environmental adaptability, the system is usually equipped with a cooling device to promptly cool the electrolyte when temperatures rise, ensuring electrolyte stability and safe system operation. However, for flow battery systems with strong environmental adaptability and a wide operating temperature range, such as iron-sulfur redox flow batteries and iron-chromium redox flow batteries, a cooling system is not necessary; in fact, high temperatures help increase the redox reaction rate and improve charge-discharge efficiency. These systems operate stably at high temperatures and are less prone to precipitation or hydrolysis. However, if an independent water-sealing and nitrogen-sealing system is used, it can easily lead to significant evaporation of electrolyte water, increased salt concentration, and ultimately electrolyte crystallization, clogging the stack and severely affecting the system's charge-discharge performance and lifespan.

[0004] With the widespread application of flow battery energy storage technology in large-scale energy storage and renewable energy grid connection, higher requirements are placed on the reliability and operating efficiency of the system. Especially in high temperature or complex environments, the management of electrolyte moisture and gas emission have become key factors affecting the stable operation of the system. Therefore, it is urgent to develop a device to solve the above-mentioned technical problems. Utility Model Content

[0005] This utility model addresses the shortcomings of existing technologies by providing an integrated condensate recovery and exhaust device that can effectively reduce electrolyte moisture loss and lower the risk of crystallization, as well as a flow battery energy storage system equipped with the aforementioned integrated condensate recovery and exhaust device, thereby optimizing the tank structure and improving the overall operating efficiency, safety, and economy of the flow battery energy storage system.

[0006] To achieve the first objective mentioned above, this utility model proposes an integrated condensate recovery and exhaust device, comprising a first pipeline, a condensate recovery device, and a water seal device. The first pipeline is connected to the inlet of the condensate recovery device, the outlet of the condensate recovery device is connected to the inlet of a tee connector, the two outlets of the tee connector are respectively connected to a second pipeline and a third pipeline, the second pipeline is connected to the inlet of the water seal device, an exhaust valve is installed on the third pipeline, a check valve is installed on the second pipeline, and a pressure sensor for monitoring the pressure inside the water seal device is provided.

[0007] In this embodiment, the condensate recovery device includes a spiral condenser tube and an external cooling source. The outlet end of the first pipeline is connected to the inlet at the bottom of the spiral condenser tube, and the outlet of the spiral condenser tube is connected to the inlet of the tee joint. The external cooling source is used to cool the spiral condenser tube.

[0008] In this embodiment, the external cooling source is a fan, and the fan is in close contact with the spiral condenser tube.

[0009] In this embodiment, the spiral condenser is made of 316L stainless steel, titanium alloy, polytetrafluoroethylene, or a polymer composite material. This gives the spiral condenser corrosion resistance and high-temperature resistance, thus adapting to the corrosiveness and temperature requirements of different electrolyte systems.

[0010] In this embodiment, the condensate recovery device is configured with multiple stages, and the multiple stages of condensate recovery devices are connected in series.

[0011] To achieve the second objective mentioned above, this utility model proposes a flow battery energy storage system, including a nitrogen generator, an electrolyte storage tank, and the aforementioned integrated condensate recovery and exhaust device. The electrolyte storage tank is provided with an inlet, an outlet, an air inlet, and an exhaust port. The nitrogen outlet of the nitrogen generator is connected to the air inlet of the electrolyte storage tank through a nitrogen delivery pipeline. A gas replenishment valve is installed on the nitrogen delivery pipeline. The inlet of the electrolyte storage tank is connected to a return pipeline, the outlet of the electrolyte storage tank is connected to an outlet pipeline, and the exhaust port of the electrolyte storage tank is connected to the first pipeline of the integrated condensate recovery and exhaust device.

[0012] In this embodiment, a control module is also included, which is connected to the exhaust valve, the replenishment valve, and the pressure sensor.

[0013] With the above structure, this utility model has the following advantages:

[0014] 1. The integrated condensate recovery and exhaust device of this utility model has a condensate recovery device installed at the inlet of the water seal device. During the operation of the flow battery energy storage system, when exhaust is required, the high-temperature gas (containing water vapor) in the electrolyte storage tank first enters the condensate recovery device for condensate recovery. The condensate recovery device of this application adopts a spiral condenser tube. When the gas flows in the spiral condenser tube, a large temperature difference is formed with the external cooling source, and the water vapor is rapidly condensed into liquid water. Under the action of gravity, the condensate flows back to the electrolyte storage tank along the tube wall of the spiral condenser tube, effectively replenishing the water lost due to evaporation, maintaining the stability of the electrolyte concentration, and preventing crystal precipitation and stack blockage.

[0015] 2. The water seal device of the integrated condensate recovery and venting device of this utility model is equipped with a pressure sensor. By monitoring the pressure inside the water seal device, the pressure inside the electrolyte storage tank can be obtained accordingly. When the pressure reaches the set value, the venting valve is opened to release the gas. The water seal device also serves as a mechanical safety device. In the event of equipment failure and excessive pressure inside the electrolyte storage tank, the gas is released to ensure the safe operation of the entire device.

[0016] 3. The condensate recovery device of this utility model adopts a spiral condenser tube, which achieves a high-efficiency condensation effect while reducing the floor space; moreover, the pipe length and diameter of the spiral condenser tube can be flexibly designed according to the scale of the equipment, thereby ensuring the efficiency of condensate recovery for different models of devices.

[0017] 4. The flow battery energy storage system of this utility model adopts an integrated device for condensate recovery and venting, which solves the practical problems of insufficient water management in the storage tank system, easy electrolyte crystallization, and complex system structure in existing flow battery energy storage systems under high temperature or wide temperature operating environments. This device can not only effectively reduce the evaporation of water inside the system and reduce the risk of electrolyte crystal precipitation due to water loss, but also achieve the integration of gas replenishment and venting functions by organically combining the water sealing device with the nitrogen sealing system, which greatly simplifies the top structure of the storage tank, reduces the number of flanges, and improves the safety and reliability of the system.

[0018] 5. The flow battery energy storage system of this utility model can automatically replenish and vent gas while recovering condensate through the control system. When the venting pressure is less than the water seal pressure, the venting gas is preferentially discharged through the venting valve to ensure system pressure balance. When the system needs to replenish gas again, the control system controls the venting valve to open and complete the automatic venting. When the pressure sensor detects that the pressure in the electrolyte storage tank is too high, the venting valve is opened to achieve automatic venting.

[0019] In summary, this device effectively prevents electrolyte crystallization caused by water evaporation, avoids stack blockage, improves system safety and reliability, reduces maintenance costs, extends equipment lifespan, and enhances overall system operating efficiency. Furthermore, its compact structure helps optimize tank space layout, providing a solid guarantee for the efficient and stable operation of flow battery energy storage systems and promoting the development of flow battery energy storage technology in large-scale energy storage and complex environment applications. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the integrated condensate recovery and exhaust device of this utility model.

[0021] Figure 2 This is a flowchart of the flow battery energy storage system of this utility model.

[0022] In the attached diagram: 1. Nitrogen generator unit; 11. Gas replenishment valve; 2. Integrated condensate recovery and exhaust device; 21. First pipeline; 22. Condensate recovery device; 221. Spiral condenser tube; 222. Fan; 23. Check valve; 24. Pressure sensor; 25. Water seal device; 26. Second pipeline; 27. Third pipeline; 28. Fourth pipeline; 29. ​​Exhaust valve; 3. Electrolyte storage tank; 4. Return pipeline; 5. Discharge pipeline. Detailed Implementation

[0023] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0024] Furthermore, the technical solutions of the various embodiments of this utility model can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0025] like Figure 1As shown, an integrated condensate recovery and exhaust device includes a first pipeline 21, a condensate recovery device 22, and a water seal device 25. The first pipeline 21 is connected to the inlet of the condensate recovery device 22, and the outlet of the condensate recovery device 22 is connected to the inlet of a three-way connector. The two outlets of the three-way connector are respectively connected to a second pipeline 26 and a third pipeline 27. The second pipeline 26 is connected to the inlet of the water seal device 25. A fourth pipeline 28 is installed on the outlet of the water seal device 25. An exhaust valve 29 is installed on the third pipeline 27, and a check valve 23 is installed on the second pipeline 26. The check valve 23 ensures that gas can only enter the water seal device 25 from the first pipeline 21 through the second pipeline 26. A pressure sensor 24 is provided inside the water seal device 25 to monitor the pressure inside the water seal device 25.

[0026] The condensate recovery device 22 can adopt various structural forms such as spiral tube structure, plate heat exchanger, finned tube, and shell-and-tube heat exchanger. In this embodiment, the condensate recovery device 22 includes a spiral condenser tube 221 and an external cooling source. Both the first pipe 21 and the spiral condenser tube 221 are vertically arranged to facilitate condensate return. The outlet end of the first pipe 21 is connected to the inlet at the bottom of the spiral condenser tube 221, and the outlet of the spiral condenser tube 221 is connected to the inlet of the tee joint. The external cooling source is a fan 222, which is in close contact with the spiral condenser tube 221.

[0027] Furthermore, the condensate recovery device 22 can be designed as a multi-stage structure, that is, multiple condensate recovery devices 22 are connected in series in the gas emission path to further improve the water recovery rate; the spiral condenser tube 221 is made of 316L stainless steel, titanium alloy, polytetrafluoroethylene, or polymer composite material. This gives the spiral condenser tube corrosion resistance and high temperature resistance, thus adapting to the corrosiveness and temperature requirements of different electrolyte systems; the spiral condenser tube 221 is closely attached to the fan 222, using the principle of efficient heat exchange to condense water vapor in the exhaust into liquid water; the spiral condenser tube 221 significantly increases the heat exchange area and condensation efficiency, and the pipe length and diameter of the spiral condenser tube 221 can be flexibly designed according to the system scale; specifically:

[0028] Heat dissipation area A = Q / (h·ΔT) (1-1)

[0029] In the formula: Q is the heat dissipation (W), and h is the heat transfer coefficient (W / m). 2 • K, because the condensate recovery device is very close to the exhaust area, is generally taken as 25-50 W / m. 2 · (between K), ΔT is the temperature difference (unit: K, the temperature difference refers to the temperature of water vapor and the surface temperature of the condensate recovery device), A is the heat dissipation area (m²). 2 ).

[0030] The length of the spiral tube is L = A / π·d (1-2)

[0031] In the formula: A is the heat dissipation area (unit: m²) 2 d is the outer diameter of the helical tube (unit: m). 2 );

[0032] The required heat exchange area and spiral tube length can be calculated using formulas (1-1) and (1-2) to ensure that the condensation efficiency meets the system requirements.

[0033] During the operation of the flow battery energy storage system, the high-temperature gas (containing water vapor) in the electrolyte storage tank 3 enters the condensate recovery device 22 through the first pipe. When the gas flows in the spiral condenser tube 221, it forms a large temperature difference with the external cooling source. The water vapor quickly condenses into liquid water. Under the action of gravity, the condensate flows back to the electrolyte storage tank 3 along the tube wall of the spiral condenser tube 221, effectively replenishing the water lost due to evaporation, maintaining the stability of the electrolyte concentration, and preventing crystal precipitation and stack blockage.

[0034] When the exhaust pressure is less than the pressure of the water seal device 25, the exhaust is discharged first through the exhaust valve 29 to ensure system pressure balance; the water seal device 25 acts as a safety device to ensure the safe operation of the entire device.

[0035] like Figure 2 The diagram shows a flow battery energy storage system, including a nitrogen generator 1, an electrolyte storage tank 3, and the aforementioned integrated condensate recovery and exhaust device 2. The electrolyte storage tank 3 is used to store the flow battery electrolyte. The electrolyte storage tank 3 is provided with an inlet, an outlet, an air inlet, and an exhaust outlet. The nitrogen outlet of the nitrogen generator 1 is connected to the air inlet of the electrolyte storage tank 3 through a nitrogen delivery pipeline. A gas replenishment valve 11 is installed on the nitrogen delivery pipeline. The inlet of the electrolyte storage tank 3 is connected to a return pipeline 4, the outlet of the electrolyte storage tank 3 is connected to an outlet pipeline 5, and the exhaust outlet of the electrolyte storage tank 3 is connected to the first pipeline 21 of the integrated condensate recovery and exhaust device 2.

[0036] Furthermore, a control module is also included. This control module is connected to the exhaust valve 29, the replenishment valve 11, and the pressure sensor 24. Through the control module, during the operation of the flow battery energy storage system, the nitrogen generated by the nitrogen generator 1 enters the electrolyte storage tank 3 through the opening of the replenishment valve 11, effectively preventing external air and moisture from flowing back into the electrolyte storage tank 3 and avoiding oxidation and contamination of the electrolyte. When excessive nitrogen is added or the electrolyte temperature rises, causing the gas in the electrolyte storage tank 3 to expand and reach the pressure set by the pressure sensor 24, the control system controls the exhaust valve 29 to open automatically to exhaust the gas, preventing overpressure damage to the equipment. At the same time, when the exhaust valve 29 is opened, trace amounts of gas (such as oxygen and hydrogen) released from the electrolyte during the charging and discharging process are also discharged from the electrolyte storage tank 3, preventing the safety hazards caused by gas accumulation in the electrolyte storage tank 3.

[0037] During the exhaust process, the water vapor carried by the high-temperature gas in the electrolyte storage tank is cooled by the condensate recovery device and condensed into condensate. The condensate flows back into the electrolyte storage tank under the action of gravity, realizing the recycling of water, effectively replenishing the water lost due to evaporation, and maintaining the stability of the electrolyte concentration.

[0038] The above are merely preferred embodiments of this utility model and do not limit the patent scope of this utility model. Any equivalent structural transformations made based on the concept of this utility model and the contents of the specification and drawings of this utility model, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this utility model.

Claims

1. A condensate recovery and exhaust integrated device, characterized in that: It includes a first pipeline, a condensate recovery device, and a water seal device. The first pipeline is connected to the inlet of the condensate recovery device, the outlet of the condensate recovery device is connected to the inlet of a tee joint, the two outlets of the tee joint are connected to a second pipeline and a third pipeline respectively, the second pipeline is connected to the inlet of the water seal device, an exhaust valve is installed on the third pipeline, a check valve is installed on the second pipeline, and a pressure sensor is installed inside the water seal device to monitor the pressure inside the water seal device.

2. The integrated condensate recovery and exhaust device according to claim 1, characterized in that: The condensate recovery device includes a spiral condenser tube and an external cooling source. The outlet end of the first pipeline is connected to the inlet at the bottom of the spiral condenser tube, and the outlet of the spiral condenser tube is connected to the inlet of the tee joint. The external cooling source is used to cool the spiral condenser tube.

3. The integrated condensate recovery and exhaust device according to claim 2, characterized in that: The external cooling source is a fan.

4. The integrated condensate recovery and exhaust device according to claim 2, characterized in that: The spiral condenser is made of 316L stainless steel, titanium alloy, polytetrafluoroethylene, or a polymer composite material.

5. The integrated condensate recovery and exhaust device according to claim 1, characterized in that: The condensate recovery device is configured with multiple stages, and the multiple stages of condensate recovery devices are connected in series.

6. A flow battery energy storage system, comprising a nitrogen generator, an electrolyte storage tank, and an integrated condensate recovery and exhaust device as described in any one of claims 1 to 5, characterized in that: The electrolyte storage tank is equipped with an inlet, an outlet, an air inlet, and an exhaust outlet. The nitrogen outlet of the nitrogen generator is connected to the air inlet of the electrolyte storage tank via a nitrogen delivery pipeline. A gas replenishment valve is installed on the nitrogen delivery pipeline. The inlet of the electrolyte storage tank is connected to a return pipeline, the outlet of the electrolyte storage tank is connected to an outlet pipeline, and the exhaust outlet of the electrolyte storage tank is connected to the first pipeline of the integrated condensate recovery and exhaust device.

7. The flow battery energy storage system according to claim 6, characterized in that: It also includes a control module, which is connected to the exhaust valve, the replenishment valve and the pressure sensor.

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