Heat recovery system in water electrolysis hydrogen production process

Abstract

The utility model discloses a heat recovery system in a water electrolysis hydrogen production process, which relates to the technical field of heat recovery and comprises a water electrolysis hydrogen production system, a multi-stage heat exchange series system and a heat storage and utilization system, and a circulating heat exchange channel is arranged between the water electrolysis hydrogen production system and the multi-stage heat exchange series system. A circulating heat exchange channel is arranged between the multi-stage heat exchange series system and the heat storage and utilization system, and an internal circulating heat compensation mechanism is arranged in the heat storage and utilization system. Through the multi-stage heat exchange series connection and heat storage and utilization mechanism, the waste heat recovery efficiency and utilization range of the electrolytic bath are effectively improved, the comprehensive utilization efficiency of energy is enhanced, a stable and reliable heat source is provided for a plurality of links such as office work, power supply and heat tracing of the electrolytic bath, and the service life of the electrolytic bath is prolonged. The obvious energy-saving and emission-reducing benefits and the wide application prospect are shown.

Description

Technical Field

[0001] This utility model belongs to the field of heat recovery technology, specifically relating to a heat recovery system in the process of producing hydrogen through water electrolysis. Background Technology

[0002] Hydrogen energy, as an important component of clean energy, is receiving increasing attention for its efficient and sustainable production technologies. However, in some regions with cold climates, energy efficiency and cost control have become key factors restricting the development of the hydrogen energy industry. In the process of producing hydrogen through water electrolysis, the electrolyzer, as the core equipment, generates a large amount of waste heat during operation. If this heat cannot be effectively recovered and utilized, it will not only lead to energy waste but may also have negative environmental impacts.

[0003] Traditional water electrolysis hydrogen production systems often overlook the potential value of waste heat from the electrolyzer, resulting in this heat energy being directly lost to the environment. Especially during cold seasons, waste heat recovery from the electrolyzer is crucial for improving overall energy efficiency and reducing operating costs. Furthermore, after the electrolyzer is shut down for hydrogen filtration, the temperature drops, requiring additional energy to reach a suitable operating temperature upon restarting, further increasing energy consumption.

[0004] Therefore, developing a system capable of efficiently recovering and rationally utilizing waste heat from electrolyzers is of paramount importance. Consequently, this invention proposes a heat energy recovery and utilization system for large-scale water electrolysis hydrogen production processes. Utility Model Content

[0005] The purpose of this invention is to address the shortcomings of existing technologies that involve energy waste, and to propose a heat recovery system for the water electrolysis hydrogen production process. This heat recovery system can significantly improve energy utilization efficiency, reduce operating costs, enhance system stability and reliability, promote energy conservation and emission reduction, and also drive the development of the hydrogen energy industry.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] Design a heat recovery system for hydrogen production through water electrolysis, comprising a water electrolysis hydrogen production system, a multi-stage heat exchange series system, and a heat storage and utilization system. A circulating heat exchange channel is provided between the water electrolysis hydrogen production system and the multi-stage heat exchange series system to transfer the heat generated in the water electrolysis hydrogen production system to the multi-stage heat exchange series system. A circulating heat exchange channel is also provided between the multi-stage heat exchange series system and the heat storage and utilization system to store the heat energy in the multi-stage heat exchange series system within the heat storage and utilization system. The heat storage and utilization system is equipped with an internal circulation heat compensation mechanism.

[0008] Furthermore, the water electrolysis hydrogen production system includes an electrolyzer, an oxygen separator and a hydrogen separator connected to the electrolyzer, and heat exchange channels formed between the layers inside the electrolyzer. The heat exchange channels constitute the heat exchange channels within the water electrolysis hydrogen production system. The cooling medium enters the multi-stage heat exchange series system through the heat exchange channels to form a circulation. The heat exchange channels are provided with a cooling medium inlet and a cooling medium outlet for the passage of the cooling medium.

[0009] Furthermore, the inner layer of the electrolytic cell has opposing protrusions and grooves on one side, and the heat exchange channel is formed between the protrusions and the grooves.

[0010] Furthermore, the multi-stage heat exchange series system is a multi-stage heat exchange system consisting of two tubular primary heat exchangers and a secondary heat exchanger connected in series. The primary heat exchanger connected in series is connected to the heat exchange channel in the water electrolysis hydrogen production system through its tube side. The tube side of the multi-stage heat exchange series system is equipped with a centrifugal pump for transporting the heat medium.

[0011] Furthermore, the heat storage and utilization system includes a water storage tank and a second centrifugal pump. The water storage tank is connected to the heat exchange tubes of the first-stage heat exchanger via a tube side, the second centrifugal pump is installed on the tube side of the heat storage and utilization system, and the heat compensation mechanism is connected to the water storage tank.

[0012] Furthermore, the heat compensation mechanism includes a heat compensation heat exchanger and a third centrifugal pump. The heat compensation heat exchanger is connected to the water storage tank through its tube side and is used to heat the water storage tank. The third centrifugal pump is installed on the tube side of the heat compensation mechanism.

[0013] Furthermore, steam flows through the shell side of the heat exchanger, and valves are installed for heat compensation regulation.

[0014] Furthermore, a fourth centrifugal pump is connected to the water storage tank, and the outlet of the fourth centrifugal pump is connected to a multi-channel heat output pipeline.

[0015] This invention proposes a heat recovery system for hydrogen production through water electrolysis. The beneficial effects are as follows: This invention, through a multi-stage heat exchange series connection and heat storage and utilization mechanism, effectively improves the recovery efficiency and utilization range of waste heat from the electrolyzer. It not only enhances the overall energy utilization efficiency but also provides a stable and reliable heat source for multiple aspects such as office work, power supply, and heat tracing of the electrolyzer itself. This demonstrates significant energy-saving and emission-reduction benefits and broad application prospects. It can significantly improve energy utilization efficiency, reduce operating costs, enhance system stability and reliability, promote energy conservation and emission reduction, expand the application range of thermal energy, enhance corporate image and competitiveness, and drive the development of the hydrogen energy industry. Specifically:

[0016] (1) This utility model can significantly improve energy utilization efficiency: Through a finely designed multi-stage heat exchange series system, the waste heat generated during the electrolysis of water to produce hydrogen can be efficiently recovered and converted into reusable thermal energy. This not only reduces energy waste but also significantly improves overall energy utilization efficiency.

[0017] (2) This utility model can reduce operating costs: Because it can recover and utilize waste heat, it reduces dependence on traditional energy sources, thereby reducing the company's operating costs. Especially in cold regions, using the recovered heat for heating, heat tracing, etc., can significantly reduce energy consumption and expenses.

[0018] (3) This utility model can enhance the stability and reliability of the system: the recovered heat is used for the heating system of the electrolyzer, which helps to quickly start the electrolyzer after the hydrogen filtration shutdown, reduces the start-up time and energy consumption, and enhances the stability and reliability of the system.

[0019] (4) This utility model can promote energy conservation and emission reduction: The implementation of this technology helps reduce greenhouse gas emissions and other pollutant emissions. By improving energy utilization efficiency, it provides strong support for the green development of the hydrogen energy industry.

[0020] (5) This utility model can expand the application scope of thermal energy: the recovered thermal energy is widely used in multiple aspects such as office area heating and lithium bromide refrigeration units, which not only improves the comprehensive utilization efficiency of energy, but also expands the application scope of thermal energy, bringing more economic and social benefits to enterprises.

[0021] (6) This utility model can enhance corporate image and competitiveness: By adopting advanced heat energy recovery and utilization technology, it helps to improve the company's environmental image and competitiveness. In today's society, environmental protection has become one of the important considerations for corporate development, and the implementation of this technology will help the company win more market recognition and customer trust.

[0022] (7) This utility model can promote the development of the hydrogen energy industry: The implementation of this technology provides strong support for energy conservation, emission reduction and sustainable development of the hydrogen energy industry. By improving energy utilization efficiency and reducing operating costs, this patent helps to promote the rapid development and widespread application of the hydrogen energy industry. Attached Figure Description

[0023] The accompanying drawings are provided to further illustrate the present invention and form part of the specification. They are used together with the embodiments of the present invention to explain the present invention, but do not constitute a limitation thereof. In the drawings:

[0024] Figure 1 This is a schematic diagram of the system structure of this utility model;

[0025] Figure 2This is a partial structural diagram of the electrolytic cell in this utility model.

[0026] The diagram is labeled as follows: 1. Electrolysis water hydrogen production system; 11. Electrolyzer; 12. Heat exchange channel; 121. Protrusion; 122. Groove; 13. Oxygen separator; 14. Hydrogen separator.

[0027] 2. Multi-stage heat exchange series system; 21. Primary heat exchanger; 22. Secondary heat exchanger; 23. Centrifugal pump No. 1; 3. Heat storage and utilization system; 31. Water storage tank; 32. Centrifugal pump No. 2; 33. Heat compensation heat exchanger; 34. Centrifugal pump No. 3; 35. Centrifugal pump No. 4. Detailed Implementation

[0028] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the protection scope of the present utility model.

[0029] In the description of this utility model, it should be noted that the terms "upper," "lower," "inner," "outer," "top / bottom," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "number one," "number two," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0030] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "sleeved / connected," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0031] The structural features of this utility model will now be described in detail with reference to the accompanying drawings.

[0032] See Figures 1-2A heat recovery system for hydrogen production through water electrolysis includes a water electrolysis hydrogen production system 1, a multi-stage heat exchange series system 2, and a heat storage and utilization system 3. A circulating heat exchange channel is provided between the water electrolysis hydrogen production system 1 and the multi-stage heat exchange series system 2 to transfer the heat generated by the reaction in the water electrolysis hydrogen production system 1 to the multi-stage heat exchange series system 2. The water electrolysis hydrogen production system 1 includes an electrolyzer 11, an oxygen separator 13 and a hydrogen separator 14 connected to the electrolyzer 11. The tanks between the layers inside the electrolyzer 11 form heat exchange channels 12. A cooling medium circulates in the heat exchange channels 12 to effectively remove the heat generated during the electrolysis process. The cooling medium is an alkaline solution. The heat exchange channel 12 constitutes the heat exchange channel in the water electrolysis hydrogen production system 1. The cooling medium enters the multi-stage heat exchange series system 2 through the heat exchange channel 12 to form a circulation. The inner layer of the electrolyzer 11 has opposite protrusions 121 and grooves 122 on the opposite side. The protrusions 121 and grooves 122 form the heat exchange channel 12. The heat exchange channel 12 with its convex and concave structure can increase the heat exchange area and improve the heat exchange efficiency. The heat exchange channel 12 is provided with a cooling medium inlet and a cooling medium outlet for the passage of the cooling medium. The multi-stage heat exchange series system 2 is a multi-stage heat exchange system consisting of two shell-and-tube type primary heat exchangers 21 and secondary heat exchangers 22 connected in series. The primary heat exchanger 21, after being connected in series, is connected to the heat exchange channel in the water electrolysis hydrogen production system 1 through the tube side to form an efficient heat transfer link. The primary heat exchanger 21 is mainly used to recover the waste heat generated in the water electrolysis hydrogen production system. The function of the secondary heat exchanger 22 is to stabilize the temperature of the return cooling medium. Steam is introduced into the shell side of the secondary heat exchanger 22 to maintain the temperature of the cooling medium at about 85°C, which is the temperature required for the operation of the electrolyzer 11. The multi-stage heat exchange series system 2 is equipped with a centrifugal pump 23 for transporting heat medium on the tube side. In terms of tube side connection, the inlet of the heat exchange channel 12 is connected to the outlet of the tube side of the secondary heat exchanger 22, realizing the recycling of the cooling medium. The outlet of the heat exchange channel 12 is connected to the inlet of the tube side of the primary heat exchanger 21. The cooling medium enters from the cooling medium inlet at the bottom of the heat exchange channel 12 and exits from the cooling medium outlet at the top. The cooling medium discharged from the cooling medium outlet at the top of the heat exchange channel 12 is connected to the primary heat exchanger 21, ensuring the effective introduction of heat and realizing the comprehensive recovery of heat.

[0033] A circulating heat exchange channel is provided between the multi-stage heat exchange series system 2 and the heat storage and utilization system 3 to store the heat energy in the multi-stage heat exchange series system 2 in the heat storage and utilization system 3. The heat storage and utilization system 3 is used to store and distribute the recovered heat, and includes a water storage tank 31 and a second centrifugal pump 32. The water storage tank 31 is connected to the heat exchange channel of the multi-stage heat exchange series system 2 via its tube side. The second centrifugal pump 32 is installed on the tube side of the heat storage and utilization system 3. Water from the water storage tank 31 is introduced into the tube side of the first-stage heat exchanger 21 through the second centrifugal pump 32 for heat exchange and control. The water storage tank 31 is also equipped with… Equipped with an electric heater, insulation jacket, and water level control system, it can supplement and maintain heat according to actual needs. The heat storage and utilization system 3 is equipped with an internal circulation heat compensation mechanism, which is connected to the water storage tank 31. The heat compensation mechanism includes a heat compensation heat exchanger 33 and a third centrifugal pump 34. The heat compensation heat exchanger 33 is connected to the water storage tank 31 through its tube side for heating the water storage tank 31. The third centrifugal pump 34 is installed on the tube side of the heat compensation mechanism. The heat compensation heat exchanger 33 is also equipped with an insulation jacket. Steam flows through the shell side of the heat compensation heat exchanger 33 for heat compensation, and a valve is installed so that the steam volume can be flexibly adjusted through the valve. To utilize the recovered heat energy, a fourth centrifugal pump 35 is connected to the water storage tank 31. The fourth centrifugal pump 35 is connected to a multi-channel heat output pipe, with the outlet pipe split into three, leading to the office area, the electrolyzer heating system, and the lithium bromide chiller unit, respectively. To address the instability of the off-grid water electrolysis hydrogen production system, the water storage tank 31 can be heated via a compensating heat exchanger 33. By increasing the temperature of the water storage tank 31, the primary heat exchanger 21 is heated, allowing the electrolyzed water temperature to quickly reach the operating temperature of 85-90℃, thus enabling the electrolyzer 1 to be put into operation quickly. This also protects the electrolyzer 1 from leakage due to thermal expansion and contraction. The electrolyzer heating system utilizes the recovered heat, effectively shortening the restart time after a shutdown. Furthermore, in winter, the office area uses the recovered heat for heating, reducing energy consumption. In summer, the lithium bromide chiller unit uses the recovered heat for cooling, improving overall energy efficiency.

[0034] This invention discloses a heat recovery system for the electrolysis of water to produce hydrogen. Specifically, in use, it achieves efficient electrolysis and heat recovery: the electrolyzer 11 is set to operate at 85℃, but during the actual reaction, the temperature inside the cell reaches 90℃ due to the heat generated by electrolysis. At this time, the cooling medium in the heat exchange channel 12 enters from the bottom inlet of the electrolyzer 11, absorbs excess heat, flows out from the top outlet, and enters a multi-stage heat exchange series system. In the multi-stage heat exchanger, heat is transferred to the water in the storage tank 31 through the first-stage heat exchanger 21, maintaining the water temperature between 75-85℃. Simultaneously, the recovered heat is also used for the electrolyzer's heat tracing system, ensuring that the electrolyzer 11 can be quickly restarted after shutdown, and the heat tracing temperature is stabilized at 85℃. Precise temperature control of water in storage tank 31: By adjusting the flow rate in the multi-stage heat exchange series system and the steam volume of the heat compensation heat exchanger 33, the water temperature in storage tank 31 is maintained at around 80℃, ensuring efficient heat recovery while avoiding energy loss due to excessively high water temperature. In addition, storage tank 31 is equipped with an electric heater and insulation jacket to cope with extreme weather or changes in heat demand. Optimized electrolytic cell heating system: The heating system utilizes the heat recovered from the multi-stage heat exchange series system, delivering hot water to the heating tubes via a shell-and-tube heat exchanger. The heating temperature is set at 85℃, ensuring rapid start-up of electrolytic cell 11 even in cold seasons. Simultaneously, the heating system is equipped with temperature sensors and regulating valves to monitor and adjust the hot water temperature in real time, ensuring the stability and reliability of the heating effect. Integrated application of heat recovery and reuse: In addition to heating the electrolytic cell and storage tank 31, some heat is also introduced into the lithium bromide refrigeration unit, achieving combined cooling and heating. This not only improves energy efficiency but also reduces the company's energy consumption and operating costs. System monitoring and fault early warning: By installing temperature sensors, flow sensors, and other equipment in the water electrolysis hydrogen production system 1, the multi-stage heat exchange series system 2, and the heat storage and utilization system 3, the system's operating status and key parameters are monitored in real time. When the system experiences abnormalities or potential faults, the monitoring system automatically issues early warning signals, reminding operators to take timely measures to address the issues. This measure effectively improves the system's reliability and safety.

[0035] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A heat recovery system for a water electrolysis hydrogen production process, comprising a water electrolysis hydrogen production system (1), a multi-stage heat exchange series system (2), and a heat storage and utilization system (3), characterized in that, A circulating heat exchange channel is provided between the water electrolysis hydrogen production system (1) and the multi-stage heat exchange series system (2) to transfer the heat generated by the reaction in the water electrolysis hydrogen production system (1) to the multi-stage heat exchange series system (2). A circulating heat exchange channel is provided between the multi-stage heat exchange series system (2) and the heat storage and utilization system (3) to store the heat energy in the multi-stage heat exchange series system (2) in the heat storage and utilization system (3). An internal circulation heat compensation mechanism is provided in the heat storage and utilization system (3).

2. The heat recovery system in the water electrolysis hydrogen production process according to claim 1, characterized in that, The water electrolysis hydrogen production system (1) includes an electrolyzer (11), an oxygen separator (13) and a hydrogen separator (14) connected to the electrolyzer (11). The tanks between the layers inside the electrolyzer (11) form heat exchange channels (12). The heat exchange channels (12) constitute the heat exchange channels in the water electrolysis hydrogen production system (1). The cooling medium enters the multi-stage heat exchange series system (2) through the heat exchange channels (12) to form a circulation. The heat exchange channels (12) are provided with a cooling medium inlet and a cooling medium outlet for the cooling medium to pass through.

3. The heat recovery system in the water electrolysis hydrogen production process according to claim 2, characterized in that, The inner layer of the electrolytic cell (11) has a protrusion (121) and a groove (122) on the opposite side of the inner layer, and the heat exchange channel (12) is formed between the protrusion (121) and the groove (122).

4. The heat recovery system in the water electrolysis hydrogen production process according to claim 1, characterized in that, The multi-stage heat exchange series system (2) is a multi-stage heat exchange system consisting of two tubular primary heat exchangers (21) and secondary heat exchangers (22) connected in series. The primary heat exchanger (21) connected in series is connected to the heat exchange channel in the water electrolysis hydrogen production system (1) through the tube side. The multi-stage heat exchange series system (2) is equipped with a centrifugal pump (23) for transporting heat medium on the tube side.

5. A heat recovery system for hydrogen production through water electrolysis according to claim 4, characterized in that, The heat storage and utilization system (3) includes a water storage tank (31) and a second centrifugal pump (32). The water storage tank (31) is connected to the heat exchange tube of the first-stage heat exchanger (21) through a tube. The second centrifugal pump (32) is installed on the tube of the heat storage and utilization system (3). The heat compensation mechanism is connected to the water storage tank (31).

6. The heat recovery system in the water electrolysis hydrogen production process according to claim 5, characterized in that, The heat compensation mechanism includes a heat compensation heat exchanger (33) and a third centrifugal pump (34). The heat compensation heat exchanger (33) is connected to the water storage tank (31) through a tube and is used for heating the water storage tank (31). The third centrifugal pump (34) is installed on the tube of the heat compensation mechanism.

7. A heat recovery system for hydrogen production through water electrolysis according to claim 6, characterized in that, Steam flows through the shell side of the heat exchanger (33), and valves are installed for heat compensation regulation.

8. A heat recovery system for hydrogen production through water electrolysis according to claim 5 or 6, characterized in that, The water storage tank (31) is connected to a fourth centrifugal pump (35), and the outlet end of the fourth centrifugal pump (35) is connected to a multi-channel heat output pipeline.

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