A hydrogen production system using water electrolysis

Abstract

The utility model provides a kind of water electrolysis hydrogen production waste heat utilization system, it is related to waste heat utilization device technical field. Including heat exchanger, heat exchanger has first heat exchange passage and second heat exchange passage, first heat exchange passage is connected with process water pipeline, still include radiator, hot water storage tank and heat exchange water pipeline, the import of second heat exchange passage's outlet, radiator, hot water storage tank, the outlet of hot water storage tank, the import of second heat exchange passage sequentially pass through heat exchange water pipeline and be connected to form closed structure.Using the utility model, the excess heat energy generated by electrolytic hydrogen production system can be effectively collected and utilized, a large amount of heat energy and domestic hot water can be collected and stored using the hot water storage tank, which can be used as a system heat preservation and domestic heat source when the hydrogen production system is shut down, and can be used as a heating source for system rapid start during system cold start process, improving the energy conversion and utilization efficiency of water electrolysis hydrogen production system, effectively solving the problem of wasting energy on one side and needing additional energy supply on the other side.

Description

Technical Field

[0001] This utility model relates to the field of waste heat utilization devices, and more specifically, to a waste heat utilization system for hydrogen production by water electrolysis. Background Technology

[0002] Hydrogen, due to its cleanliness, pollution-free nature, and high calorific value, is hailed as the most promising clean energy source of the 21st century. Hydrogen production through water electrolysis refers to the process where water molecules are decomposed into oxygen and hydrogen in an electrolyzer under the influence of direct current. It is currently one of the most important methods for producing green hydrogen, characterized by its environmental friendliness, flexible production, and high product purity, and is of great significance in addressing the fluctuations in renewable energy consumption. However, current water electrolysis hydrogen production devices have an electrolysis efficiency of approximately 60%-70%, and the unused electrical energy is converted into heat. A significant portion of this heat, besides maintaining the temperature of the electrolyzer (40-80℃), is carried away from the electrolyzer outlet by hydrogen, oxygen, and electrolyte, ultimately being released into the environment and wasted, resulting in substantial energy waste.

[0003] Furthermore, in cold regions during winter, the auxiliary rooms and process rooms of the water electrolysis hydrogen production system require additional heating after the system is shut down to maintain the ambient temperature above 0°C and prevent water tanks and pipes from freezing. Large-scale water electrolysis hydrogen production systems require staff to take turns on duty and maintain the system. In cold regions, additional energy is needed to heat the living and working areas of the staff and provide hot water for daily life. The electrolysis system takes a long time to reach the appropriate water electrolysis temperature from cold start, especially in high-altitude and cold regions where large-scale hydrogen production systems can take 2-3 hours to reach the rated operating state, which seriously affects the electrolysis efficiency.

[0004] Therefore, in the existing technology, a large amount of heat energy is wasted after water electrolysis, but additional energy is needed in places such as auxiliary rooms, process rooms, living and office areas, and cold start of the electrolysis system, resulting in a large amount of heat energy after water electrolysis not being well recovered and utilized. Utility Model Content

[0005] The purpose of this invention is to provide a waste heat utilization system for hydrogen production via water electrolysis. This system can effectively collect and rationally utilize the excess heat energy generated by the hydrogen electrolysis system. It cleverly utilizes a hot water storage tank to collect and store a large amount of heat energy and domestic hot water. This tank can be used as a system insulation and domestic heat source when the hydrogen production system is shut down, and as a heating source for rapid system startup during cold starts. This improves the energy conversion and utilization efficiency of the water electrolysis hydrogen production system and effectively solves the problem of wasting energy while requiring additional energy supply.

[0006] The technical solution adopted in this utility model is as follows:

[0007] This application provides a waste heat utilization system for hydrogen production via water electrolysis, including a heat exchanger with a first heat exchange channel and a second heat exchange channel. The first heat exchange channel is connected in series with a process water pipeline. The system also includes a radiator, a hot water storage tank, and a hot water exchange pipeline. The hot water storage tank has an inlet and an outlet. The outlet of the second heat exchange channel, the radiator, the inlet of the hot water storage tank, the outlet of the hot water storage tank, and the inlet of the second heat exchange channel are connected in series via the hot water exchange pipeline to form a closed structure.

[0008] Furthermore, in some embodiments of this utility model, a radiator is connected in series between the outlet of the hot water storage tank and the inlet of the second heat exchange channel.

[0009] Furthermore, in some embodiments of this utility model, the radiator is connected in series with a radiator control valve, and also includes a radiator parallel pipeline, which is equipped with a radiator parallel control valve; the series structure formed by the radiator and the radiator control valve is connected in parallel with the radiator parallel pipeline.

[0010] Furthermore, in some embodiments of this utility model, there are multiple radiators connected in series.

[0011] Furthermore, in some embodiments of this utility model, the radiator is connected in series with a radiator control valve, and also includes a radiator parallel pipeline, which is equipped with a radiator parallel control valve; the series structure formed by the radiator and the radiator control valve is connected in parallel with the radiator parallel pipeline.

[0012] Furthermore, in some embodiments of this utility model, the hot water storage tank is connected to a tap water inlet pipe and a hot water supply outlet pipe. The tap water inlet pipe is equipped with a tap water control valve, and the hot water supply outlet pipe is equipped with a hot water supply outlet control valve.

[0013] Furthermore, in some embodiments of this utility model, a hydrogen production feedstock water pump is connected in series in the process water pipeline, and a variable frequency pump is connected in series in the heat exchange water pipeline.

[0014] Furthermore, in some embodiments of this utility model, a flow transmitter and a temperature transmitter are provided at the outlet end of the process water pipeline located in the first heat exchange channel.

[0015] Furthermore, in some embodiments of this utility model, a flow transmitter and a temperature transmitter are provided at the outlet end of the hot water storage tank.

[0016] Compared with the prior art, the present invention has at least the following advantages or beneficial effects:

[0017] The waste heat recovery system for water electrolysis hydrogen production provided in this application achieves effective utilization and management of waste heat from the water electrolysis hydrogen production system through heat energy recovery and reuse, thereby improving the energy conversion and utilization efficiency of the system. A hot water storage tank is installed to achieve efficient collection and utilization of the heat energy generated by the system. This tank has high heat storage density, is pollution-free, and provides stable output temperature and heat output, effectively solving the problems of heating for staff and insulation during system shutdowns. By reusing waste heat, the system addresses the slow cold start issue of the water electrolysis hydrogen production system, improving its overall efficiency. This effectively solves the problem of simultaneously wasting energy and requiring additional energy supply, achieving a "double saving" effect. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 A schematic diagram of the waste heat utilization system for hydrogen production by water electrolysis provided in this embodiment of the utility model.

[0020] Icons: 1-Process room; 2-Process water pipeline; 3-Hot water exchange pipeline; 4-Heat exchanger; 5-Auxiliary room; 6-Living and office area; 7-Hot water storage tank; 8-Variable frequency pump; 9-Radiator; 91-Radiator control valve; 92-Radiator parallel pipeline; 93-Radiator parallel control valve; 10-Hydrogen production feedstock water pump; 11-Heating radiator; 111-Radiator control valve; 112-Radiator parallel pipeline; 113-Radiator parallel control valve; 12-Tap water inlet pipe; 121-Tap water control valve; 13-Hot water supply outlet pipe; 131-Hot water supply outlet control valve; 14-Flow transmitter; 15-Temperature transmitter; 16-On / off valve. Detailed Implementation

[0021] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0022] Example

[0023] Please refer to Figure 1 This embodiment provides a waste heat utilization system for water electrolysis hydrogen production, including a heat exchanger 4. The heat exchanger 4 has a first heat exchange channel and a second heat exchange channel. A process water pipeline 2 is connected in series in the first heat exchange channel. In this embodiment, the process water pipeline 2 is mainly used to supply raw water for electrolysis and to remove excess heat from the electrolyzer. Both ends of the process water pipeline 2 are connected to the electrolyzer. The water electrolysis hydrogen production process system and the electrolyzer equipment are placed in a... Figure 1 The process room 1 shown is the core area for hydrogen production via water electrolysis and also the area where waste heat is generated. Hydrogen production via water electrolysis can employ alkaline water electrolysis, proton exchange membrane (PEM) water electrolysis, or anion exchange membrane (EEM) water electrolysis. It can be directly connected to renewable energy sources such as wind power, photovoltaic (PV), and solar thermal power, or connected to the power grid, as needed. The electrolyzed water, carrying heat, is fed into the first heat exchange channel of heat exchanger 4 through process water pipeline 2. After heat exchange in heat exchanger 4, it is output through the first heat exchange channel and then returned to the electrolyzer for reuse in the electrolysis process.

[0024] It also includes radiators 11, a hot water storage tank 7, and a hot water exchange pipe 3. The hot water storage tank 7 has an inlet and an outlet. In this embodiment, two radiators 11 are preferably used and connected in series. Figure 1 As shown, a radiator 11 is installed in the auxiliary room 5, which mainly houses the electrolysis hydrogen production auxiliary system, such as a pure water machine, water tank, and water pump. This radiator 11 is used to heat the auxiliary room 5. Another radiator 11 is installed in the living and office area 6, which is mainly a rest or workspace for staff. This radiator 11 is used to heat the living and office area 6. The outlet of the second heat exchange channel, the radiator 11, the inlet of the hot water storage tank 7, the outlet of the hot water storage tank 7, and the inlet of the second heat exchange channel are connected in series through the hot water exchange pipeline 3 to form a closed structure. In this embodiment, the hot water exchange pipeline 3 is mainly used to remove the waste heat generated by electrolysis from the electrolysis system and supply it to the downstream for recycling and conversion. The heat exchanger 4 is the main equipment for heat exchange between the process water pipeline 2 and the hot water exchange pipeline 3. It can be a plate heat exchanger, a shell-and-tube heat exchanger, or other suitable heat exchange equipment. The hot water storage tank 7 in this embodiment is the main heat storage system of this solution. It can be made by connecting multiple modular, insulated water tanks in parallel. The total heat storage capacity is redundantly designed according to the scale of the hydrogen production system and is directly connected to the hot water exchange pipeline 3.

[0025] A radiator 9 is connected in series between the outlet of the hot water storage tank 7 and the inlet of the second heat exchange channel. The radiator 9 is connected in series with a radiator control valve 91, and also includes a radiator parallel pipe 92. The radiator parallel pipe 92 is equipped with a radiator parallel control valve 93. The series structure formed by the radiator 9 and the radiator control valve 91 is connected in parallel with the radiator parallel pipe 92. By setting the radiator 9, the hot water flowing in the hot water exchange pipe 3 can be cooled. In this embodiment, the radiator 9 is used to dissipate heat that the entire system cannot contain in a timely manner, ensuring that the hydrogen production system does not exceed the design temperature. It is mainly used for long-term operation of the hydrogen production system, or in the warm summer season when there is no heating demand or a reduction in domestic hot water, as well as other temporary emergency situations.

[0026] like Figure 1As shown, in some embodiments, the radiator 11 is connected in series with a radiator control valve 111, and also includes a radiator parallel pipe 112, which is equipped with a radiator parallel control valve 113; the series structure formed by the radiator 11 and the radiator control valve 111 is connected in parallel with the radiator parallel pipe 112. The hot water storage tank 7 is connected to a tap water inlet pipe 12 and a hot water supply outlet pipe 13. The tap water inlet pipe 12 is equipped with a tap water control valve 121, and the hot water supply outlet pipe 13 is equipped with a hot water supply outlet control valve 131. In this embodiment, the outlet end of the hot water storage tank 7 and the outlet end of the radiator 11 corresponding to the living and office area 6 are both equipped with a switch valve 16. The switch valve 16, the tap water control valve 121, and the hot water supply outlet control valve 131 are used for shutting off the equipment during emergencies, repairs, and maintenance. In this embodiment, the tap water inlet pipe 12 is used to replenish the water consumed by the hot water storage tank 7 in a timely manner, and the hot water supply outlet pipe 13 is used to supply hot water for domestic use to the living and office areas 6.

[0027] In this embodiment, the process water pipeline 2 is connected in series with a hydrogen production feedstock water pump 10, and the hot water exchange pipeline 3 is connected in series with a variable frequency pump 8. The variable frequency pump 8 is the power source for the hot water exchange pipeline 3. The variable frequency design helps control the flow rate of the hot water exchange pipeline 3, keeping the temperature of the entire hydrogen production system within a stable range. The hydrogen production feedstock water pump 10 is the power source for the process water pipeline 2.

[0028] like Figure 1 As shown, in some embodiments, the process water pipeline 2 is equipped with a flow transmitter 14 and a temperature transmitter 15 at the outlet end of the first heat exchange channel. The hot water storage tank 7 is also equipped with a flow transmitter 14 and a temperature transmitter 15 at its outlet end. In this embodiment, both the auxiliary room 5 and the living and office area 6 can be equipped with temperature transmitters 15. Each temperature transmitter 15 is mainly used to monitor the temperature of the auxiliary room 5, the living and office area 6, the hot water exchange pipeline 3, and the process water pipeline 2 in real time, so that staff can control the opening and closing of relevant valves based on the relevant temperature information. The flow transmitter 14 corresponding to the hot water exchange pipeline 3 is used to monitor the flow rate of the hot water exchange pipeline 3 in real time, which staff can use to control the operating frequency of the variable frequency pump 8. The flow transmitter 14 corresponding to the process water pipeline 2 is used to monitor the flow rate of the process water pipeline 2 in real time, which staff can use to adjust the flow rate of the hydrogen production feedstock pump 10.

[0029] The specific working principle is as follows:

[0030] When the system operates smoothly during the cold winter, the process water pipeline 2 carries away the waste heat generated during the electrolysis hydrogen production process. The hot water exchange pipeline 3 exchanges heat with the process water pipeline 2 through the heat exchanger 4. The parallel control valve 113 of the two radiators is closed, and the control valve 111 of the two radiators is open. The waste heat carried away by the hot water exchange pipeline 3 is used to supply heat to the auxiliary rooms 5 and the living and office areas 6. The remaining heat is carried in by the hot water and stored in the hot water storage tank 7. The hot water storage tank 7 supplies domestic hot water to the living and office areas 6 through the hot water supply and output pipeline 13.

[0031] When the system shuts down during cold winter months, the parallel control valves 113 for the two radiators close, the radiator control valve 91 closes, the two radiator control valves 111 open, and the parallel control valve 93 opens. The variable frequency pump 8 starts, driving the water circulation in the hot water exchange pipeline 3. The hot water stored in the hot water storage tank 7 serves as a heat source to heat the auxiliary rooms 5 and the living and office areas 6, maintaining the ambient temperature of these areas within a suitable range. Simultaneously, the hydrogen production feedstock water pump 10 starts, and the process water pipeline 2 maintains a certain flow rate. The heat stored in the hot water storage tank 7 is transferred to the process water pipeline 2 through the hot water exchange pipeline 3 and the heat exchanger 4 to maintain the process water pipeline 2 at a suitable temperature and prevent the risk of freezing and blockage.

[0032] When the hydrogen production system is cold-started, the radiator control valve 91 is closed and the radiator parallel control valve 93 is opened, increasing the operating frequency of the variable frequency pump 8. The heat stored in the hot water storage tank 7 is transferred to the process water pipeline 2 through the hot water exchange pipeline 3 and the heat exchanger 4, which quickly heats the raw water for hydrogen production by electrolysis, improves the cold start speed of the hydrogen production system, and allows the system to reach its rated operating conditions in a shorter time, thereby improving the overall efficiency of the hydrogen production system.

[0033] When the water electrolysis hydrogen production unit operates at high load for a long time, and the temperature of the auxiliary room 5 and the living and office area 6 reaches the upper limit and the hot water storage tank 7 is saturated, or during the warm summer season when there is no heating demand in the auxiliary room 5 and the living and office area 6 or the domestic hot water demand is reduced, and the entire system cannot accommodate and utilize more waste heat, the two radiator parallel control valves 113 and radiator control valve 91 open, the two radiator control valves 111 close, the radiator parallel control valve 93 closes, and the radiator 9 opens, so as to dissipate the heat that the entire system cannot accommodate in time, ensure that the hydrogen production system does not exceed the design temperature, and maintain the stable operation of the hydrogen production system.

[0034] The waste heat recovery system for water electrolysis hydrogen production provided in this application effectively utilizes and manages the waste heat from the water electrolysis hydrogen production system through heat energy recovery and reuse, thereby improving the energy conversion and utilization efficiency of the system. A hot water storage tank is installed to efficiently collect and utilize the heat energy generated by the system, offering high heat storage density, no pollution, and stable output temperature and heat output, effectively solving the problems of heating for staff and insulation during system shutdowns. By reusing waste heat, the system addresses the slow cold start issue of the water electrolysis hydrogen production system, improving its overall efficiency. This effectively solves the problem of simultaneously wasting energy and requiring additional energy supply, achieving a "double saving" effect.

[0035] Furthermore, unless otherwise explicitly specified or limited, the terms "installation" and "connection" in this application embodiment should be interpreted broadly. For example, "connection" can be a detachable connection or a non-detachable connection; it can be a direct connection or an indirect connection through an intermediate medium. The terms "upper," "lower," "left," "right," "inner," "outer," and "side," etc., are merely for reference to the direction in the accompanying drawings or the usual placement of the product during use. They are only for clearly describing this application and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. They should not be construed as limitations on this application. The terms "first," "second," etc., are only used for distinguishing descriptions and should not be construed as indicating or implying relative importance; "multiple" refers to at least two. In this application embodiment, the limitations on relative positional relationships such as parallel, perpendicular, and aligned are all relative to the current technological level and are not absolutely strict limitations. Slight deviations are allowed; approximations of parallel, perpendicular, and aligned are all acceptable. For example, "A and B are parallel" means that A and B are parallel or approximately parallel, and the angle between A and B can be between 0 degrees and 10 degrees.

[0036] The above are only some embodiments and implementation methods of this application. The protection scope of this application is not limited thereto. In the absence of conflict, the embodiments and features in the embodiments of this application can be combined with each other. Any combination of features in different embodiments is also within the protection scope of this application. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the protection scope of this application.

Claims

1. A waste heat utilization system for hydrogen production via water electrolysis, comprising a heat exchanger (4), wherein the heat exchanger (4) has a first heat exchange channel and a second heat exchange channel, characterized in that, The first heat exchange channel is connected in series with a process water pipeline (2), and also includes a radiator (11), a hot water storage tank (7) and a hot water exchange pipeline (3). The hot water storage tank (7) has an inlet and an outlet. The outlet of the second heat exchange channel, the radiator (11), the inlet of the hot water storage tank (7), the outlet of the hot water storage tank (7), and the inlet of the second heat exchange channel are connected in series through the hot water exchange pipeline (3) to form a closed structure.

2. The waste heat utilization system for hydrogen production by water electrolysis according to claim 1, characterized in that, A radiator (9) is connected in series between the outlet of the hot water storage tank (7) and the inlet of the second heat exchange channel.

3. The waste heat utilization system for hydrogen production by water electrolysis according to claim 2, characterized in that, The radiator (9) is connected in series with a radiator control valve (91) and also includes a radiator parallel pipeline (92). The radiator parallel pipeline (92) is equipped with a radiator parallel control valve (93). The series structure formed by the radiator (9) and the radiator control valve (91) is connected in parallel with the radiator parallel pipeline (92).

4. The waste heat utilization system for hydrogen production by water electrolysis according to claim 1, characterized in that, The number of radiators (11) is multiple and each radiator (11) is connected in series.

5. A waste heat utilization system for hydrogen production via water electrolysis according to claim 1, characterized in that, The radiator (11) is connected in series with a radiator control valve (111) and also includes a radiator parallel pipe (112). The radiator parallel pipe (112) is equipped with a radiator parallel control valve (113). The series structure formed by the radiator (11) and the radiator control valve (111) is connected in parallel with the radiator parallel pipe (112).

6. The waste heat utilization system for hydrogen production by water electrolysis according to claim 1, characterized in that, The hot water storage tank (7) is connected to a tap water inlet pipe (12) and a hot water supply outlet pipe (13). The tap water inlet pipe (12) is equipped with a tap water control valve (121), and the hot water supply outlet pipe (13) is equipped with a hot water supply outlet control valve (131).

7. A waste heat recovery system for hydrogen production via water electrolysis according to claim 1, characterized in that, The process water pipeline (2) is connected in series with a hydrogen production raw material water pump (10), and the heat exchange water pipeline (3) is connected in series with a variable frequency pump (8).

8. A waste heat recovery system for hydrogen production via water electrolysis according to claim 1, characterized in that, The process water pipeline (2) is equipped with a flow transmitter (14) and a temperature transmitter (15) at the outlet end of the first heat exchange channel.

9. A waste heat recovery system for hydrogen production via water electrolysis according to claim 1, characterized in that, The outlet end of the hot water storage tank (7) is equipped with a flow transmitter (14) and a temperature transmitter (15).

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