Waste heat cascade utilization pipeline system of electric heating hydrogen multi-energy system

Abstract

This application belongs to the field of hydrogen energy utilization technology, specifically disclosing a waste heat cascade utilization pipeline system for an electrothermal hydrogen multi-energy system, including: an electrothermal hydrogen multi-energy system, a chiller, and a hot water storage tank; during the electrolysis of water to produce hydrogen, the outlet of the chiller is connected to the inlet of the metal hydrogen storage unit and the gas purification unit of the electrolyzer; the outlet of the metal hydrogen storage unit is connected to the inlet of the power electronic conversion unit; the first outlet of the room temperature tap water or the hot water storage tank is connected to the inlet of the alkaline cooling unit of the electrolyzer; the inlet of the hot water storage tank is connected to the outlet of the alkaline cooling unit of the electrolyzer; during the fuel cell power generation process, the outlet of the chiller is connected to the inlet of the power electronic conversion unit; the second outlet of the hot water storage tank is connected to the inlet of the heat exchanger, and the outlet of the heat exchanger is connected to the inlet of the metal hydrogen storage unit; the outlet of the metal hydrogen storage unit is directly connected to the inlet of the heat exchanger or connected to the inlet of the heat exchanger through the hot water storage tank; the outlet of the chiller is connected to the inlet of the power electronic conversion unit.

Description

Technical Field

[0001] This application belongs to the field of hydrogen energy utilization technology, and more specifically, relates to a waste heat cascade utilization pipeline system of an electrothermal hydrogen multi-energy system. Background Technology

[0002] Hydrogen energy is an important carrier for the large-scale and efficient utilization of renewable energy, possessing advantages such as large-scale and long-term energy storage. Renewable energy-power-hydrogen cogeneration technology uses hydrogen as an energy carrier, integrating electrolysis for hydrogen production, hydrogen storage, and fuel cell modules. This enables the stable absorption of renewable energy and has broad application prospects in distributed energy supply solenoid valves. However, in renewable energy-based electro-thermal-hydrogen multi-energy systems, the operation of water electrolysis for hydrogen production, hydrogen storage alloy for hydrogen absorption and desorption, fuel cell power generation, and power conversion devices only considers the energy supply and demand relationship between different devices, neglecting the issue of different energy grades of multi-source heat flow. This results in low system energy utilization and low waste heat recovery grade. Summary of the Invention

[0003] To address the shortcomings of related technologies, this application provides a waste heat cascade utilization pipeline system for an electrothermal hydrogen multi-energy system, aiming to solve the problems of low energy utilization rate and low waste heat recovery grade in the electrothermal hydrogen multi-energy system.

[0004] This application provides a waste heat cascade utilization pipeline system for an electrothermal hydrogen multi-energy system, including: an electrothermal hydrogen multi-energy system, a chiller, and a hot water storage tank;

[0005] The electrothermal multi-energy system includes: an electrolyzer gas purification unit, an electrolyzer alkaline solution cooling unit, a power electronic conversion unit, a fuel cell unit, a heat exchanger, and a metal hydrogen storage unit;

[0006] In the electrolysis of water to produce hydrogen in the electrothermal hydrogen multi-energy system, the outlet of the chiller is connected to the inlet of the metal hydrogen storage unit and the gas purification unit of the electrolyzer through pipelines, providing cooling water to the metal hydrogen storage unit and the gas purification unit of the electrolyzer; the outlet of the metal hydrogen storage unit is connected to the inlet of the power electronic conversion unit through pipelines, providing cooling water to the power electronic conversion unit; the first outlet of the room temperature tap water or the hot water storage tank is connected to the inlet of the alkaline solution cooling unit of the electrolyzer through pipelines, providing cooling water to the alkaline solution cooling unit of the electrolyzer; the inlet of the hot water storage tank is connected to the outlet of the alkaline solution cooling unit of the electrolyzer through pipelines for waste heat storage.

[0007] In the fuel cell power generation process of the electrothermal hydrogen multi-energy system, the outlet of the chiller is connected to the inlet of the power electronic conversion unit through a pipeline, providing cooling water to the power electronic conversion unit; the second outlet of the hot water storage tank is connected to the inlet of the heat exchanger through a pipeline, exchanging heat with the heat exchanger; the outlet of the heat exchanger is connected to the inlet of the metal hydrogen storage unit through a pipeline, providing heat to the metal hydrogen storage unit; the outlet of the metal hydrogen storage unit is directly connected to the inlet of the heat exchanger through a pipeline, exchanging heat with the heat exchanger, or the outlet of the metal hydrogen storage unit is connected to the inlet of the heat exchanger through the hot water storage tank through a pipeline, exchanging heat in the hot water storage tank; the outlet of the chiller is connected to the inlet of the power electronic conversion unit through a pipeline, providing cooling water to the power electronic conversion unit.

[0008] In some embodiments, the waste heat cascade utilization pipeline system also includes multiple solenoid valves during the water electrolysis hydrogen production process:

[0009] The outlet of the chiller is connected to the inlet of the first solenoid valve through a pipe, and the inlet of the chiller is connected to the outlet of the second solenoid valve through a pipe.

[0010] The first outlet of the first solenoid valve is connected to the inlet of the gas purification unit of the electrolytic cell through a pipe, and the outlet of the gas purification unit of the electrolytic cell is connected to the first inlet of the second solenoid valve through a pipe.

[0011] The second outlet of the first solenoid valve is connected to the inlet of the third solenoid valve via a pipe. The first outlet of the third solenoid valve is connected to the first inlet of the fourth solenoid valve via a pipe. The outlet of the fourth solenoid valve is connected to the inlet of the metal hydrogen storage unit via a pipe. The outlet of the metal hydrogen storage unit is connected to the inlet of the fifth solenoid valve via a pipe. The first outlet of the fifth solenoid valve is connected to the first inlet of the sixth solenoid valve via a pipe. The outlet of the sixth solenoid valve is connected to the inlet of the power electronic conversion unit via a pipe. The outlet of the power electronic conversion unit is connected to the second inlet of the second solenoid valve via a pipe.

[0012] In some embodiments, the chiller preferentially supplies cooling water to the electrolyzer gas purification unit.

[0013] In some embodiments, the outlet of the room temperature tap water or the hot water storage tank is connected to the inlet of the alkali cooling unit of the electrolytic cell via a pipe, including:

[0014] When the water level in the hot water storage tank has not reached the maximum water level, room temperature tap water is connected to the inlet of the electrolytic cell's alkali cooling unit through a pipe; or,

[0015] When the water level in the hot water storage tank reaches its maximum value, the outlet of the hot water storage tank is connected to the inlet of the alkaline solution cooling unit of the electrolytic cell through a pipe.

[0016] In some embodiments, the waste heat cascade utilization pipeline system also includes multiple solenoid valves;

[0017] When the water level in the hot water storage tank has not reached the maximum water level, the first inlet of the seventh solenoid valve receives room temperature tap water, and the outlet is connected to the inlet of the alkaline cooling unit of the electrolytic cell through a pipe; or, when the water level in the hot water storage tank reaches the maximum water level, the first inlet of the seventh solenoid valve is closed, the first outlet of the hot water storage tank is connected to the second inlet of the seventh solenoid valve through a pipe, and the outlet of the seventh solenoid valve is connected to the inlet of the alkaline cooling unit of the electrolytic cell through a pipe.

[0018] The outlet of the alkali cooling unit of the electrolytic cell is connected to the inlet of the eighth solenoid valve through a pipe, and the outlet of the eighth solenoid valve is connected to the first inlet of the hot water storage tank through a pipe.

[0019] In some embodiments, the waste heat cascade utilization pipeline system also includes multiple solenoid valves during the fuel cell power generation process:

[0020] The second outlet of the hot water storage tank is connected to the first inlet of the ninth solenoid valve through a pipe, and the outlet of the ninth solenoid valve is connected to the inlet of the heat exchanger through a pipe; the outlet of the heat exchanger is connected to the second inlet of the fourth solenoid valve through a pipe, and the outlet of the fourth solenoid valve is connected to the inlet of the metal hydrogen storage unit through a pipe.

[0021] In some embodiments, the outlet of the metal hydrogen storage unit is directly connected to the inlet of the heat exchanger via a pipeline, including:

[0022] When the water temperature at the outlet of the metal hydrogen storage unit does not reach the set temperature of the hot water storage tank, the outlet of the metal hydrogen storage unit is connected to the inlet of the fifth solenoid valve through a pipe, and the second outlet of the fifth solenoid valve is connected to the inlet of the tenth solenoid valve through a pipe.

[0023] The first outlet of the tenth solenoid valve is connected to the second inlet of the ninth solenoid valve through a pipe, and the outlet of the ninth solenoid valve is connected to the inlet of the heat exchanger through a pipe.

[0024] In some embodiments, the outlet of the metal hydrogen storage unit is connected to the inlet of the heat exchanger via a pipeline through a hot water storage tank, including:

[0025] When the water temperature at the outlet of the metal hydrogen storage unit reaches the set temperature of the hot water storage tank, the outlet of the metal hydrogen storage unit is connected to the inlet of the fifth solenoid valve through a pipe, and the second outlet of the fifth solenoid valve is connected to the inlet of the tenth solenoid valve through a pipe.

[0026] The second outlet of the tenth solenoid valve is connected to the second inlet of the hot water storage tank via a pipe;

[0027] The second outlet of the hot water storage tank is connected to the first inlet of the ninth solenoid valve through a pipe, and the outlet of the ninth solenoid valve is connected to the inlet of the heat exchanger through a pipe.

[0028] In some embodiments, the heat stored in the hot water storage tank during the hydrogen production process via water electrolysis is used in the fuel cell power generation process.

[0029] In some embodiments, during the electrolysis of water to produce hydrogen, the water in the hot water storage tank is used for the circulating cooling of the alkaline solution cooling unit of the electrolyzer; during the fuel cell power generation process, the water in the hot water storage tank serves as the heat exchange medium for the metal hydrogen storage unit, and circulates with the fuel cell unit in the heat exchanger.

[0030] The waste heat cascade utilization pipeline system of the electrothermal hydrogen multi-energy system provided in this application embodiment, during the water electrolysis hydrogen production process, considers the temperature difference between the power electronic conversion unit and the metal hydrogen storage unit. After the chiller provides cooling water to the metal hydrogen storage unit, the metal hydrogen storage unit provides cooling water to the power electronic conversion unit, thereby realizing the cascade utilization of energy. During the water electrolysis hydrogen production process, the waste heat of the alkaline solution cooling unit of the electrolyzer is stored in the hot water storage tank and used in the fuel cell power generation process, realizing the utilization of energy across time scales. During the fuel cell power generation process, the water in the hot water storage tank serves as the heat exchange medium for the metal hydrogen storage unit, and circulates with the fuel cell unit in the heat exchanger, realizing the cascade utilization of energy between the fuel cell unit and the metal hydrogen storage unit, and improving the energy quality of the heat source of the hot water storage tank, thereby greatly improving the energy utilization efficiency and waste heat recovery quality of the system. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in this application or related technologies, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a schematic diagram of the waste heat cascade utilization pipeline system of the electrothermal hydrogen multi-energy system provided in the embodiments of this application;

[0033] Figure 2 This is a schematic diagram illustrating the principle of the electrolytic hydrogen production process of the electrothermal hydrogen multi-energy system provided in the embodiments of this application;

[0034] Figure 3 This is a schematic diagram illustrating the principle of the fuel cell power generation process of the electrothermal hydrogen multi-energy system provided in this application embodiment. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0036] Figure 1 This is a schematic diagram of the waste heat cascade utilization pipeline system of the electrothermal hydrogen multi-energy system provided in the embodiments of this application, as shown below. Figure 1 As shown, the waste heat cascade utilization pipeline system includes at least: an electric-thermal hydrogen multi-energy system, a chiller, and a hot water storage tank. The electric-thermal hydrogen multi-energy system includes at least: an electrolyzer gas purification unit, an electrolyzer alkaline solution cooling unit, a power electronic conversion unit, a fuel cell unit, a heat exchanger, and a metal hydrogen storage unit.

[0037] The electric heater multi-energy system includes a water electrolysis hydrogen production process and a fuel cell power generation process, which correspond to the hydrogen storage process and hydrogen release process of the metal hydrogen storage unit, respectively.

[0038] In the hydrogen production process via water electrolysis, the metal hydrogen storage unit, the electrolyzer gas purification unit, the power electronics conversion unit, and the electrolyzer alkaline solution cooling unit all release heat. The chiller's outlet is connected via pipes to the inlets of both the metal hydrogen storage unit and the electrolyzer gas purification unit, allowing the chiller to directly supply cooling water to both units. Optionally, the chiller may preferentially supply cooling water to the electrolyzer gas purification unit. Here, "connected" means linked and interconnected.

[0039] During the hydrogen production process by water electrolysis, the operating temperature of the power electronic conversion unit is higher than that of the hydrogen storage unit. Therefore, the cooling water outlet of the metal hydrogen storage unit is connected to the cooling water inlet of the power electronic conversion unit through a pipeline, so that the metal hydrogen storage unit provides cooling water to the power electronic conversion unit, instead of the chiller directly providing cooling water to the power electronic conversion unit, thereby realizing the cascade utilization of energy.

[0040] In the hydrogen production process via water electrolysis, the inlet of the alkaline solution cooling unit of the electrolyzer is connected to room temperature tap water for cooling. The outlet is connected to the inlet of a hot water storage tank via a pipe, where waste heat is stored. When the water level in the hot water storage tank reaches its maximum value, the water in the tank is used to circulate and cool the alkaline solution cooling unit of the electrolyzer.

[0041] During fuel cell power generation, the fuel cell unit and power electronic conversion unit release heat, while the metal hydrogen storage unit absorbs heat. A chiller directly supplies cooling water to the power electronic conversion unit and only to it. A heat exchanger facilitates heat exchange between the hot water storage tank and the fuel cell unit. The water after heat exchange flows into the metal hydrogen storage unit, and its outlet is re-entered into the heat exchanger. As heat exchange continues, the temperature at the heat exchanger inlet gradually increases, leading to a decrease in heat exchange capacity. When the temperature rises to a set threshold, it can no longer meet the heat dissipation requirements of the fuel cell unit, and the circulating water is injected into the hot water storage tank for a new heat exchange cycle. The hot water circulation during the hydrogen release process of the metal hydrogen storage unit and the cooling water circulation inside the fuel cell unit exchange heat through the heat exchanger, thus achieving cascaded energy utilization.

[0042] Optionally, the waste heat cascade utilization pipeline system also includes multiple solenoid valves. These solenoid valves are multi-way valves, such as three-way valves or four-way valves, and the specific type can be selected according to actual needs. Multiple solenoid valves are used to connect various units or equipment via pipelines. By controlling the opening and closing of each valve in the multi-way system, the flow direction of the medium in the pipeline can be controlled. By detecting the temperature of each unit, the opening degree of each valve can be controlled to achieve control of the flow rate of the medium in the pipeline.

[0043] Generally, in an electrothermal hydrogen multi-energy system, the operating temperature of the alkaline cooling unit in the electrolyzer is 80-90℃, the operating temperature of the gas purification unit in the electrolyzer is 10-15℃, the operating temperature of the power electronic conversion unit is 30-40℃, the operating temperature of the fuel cell unit is 70-75℃, the operating temperature of the hydrogen storage unit during the hydrogen storage process is 15-20℃, and the operating temperature of the hydrogen release process is 50-60℃.

[0044] Figure 2 This is a schematic diagram of the principle of the electrothermal hydrogen multi-energy system for producing hydrogen by electrolysis of water provided in the embodiments of this application. In the process of producing hydrogen by electrolysis of water in the electrothermal hydrogen multi-energy system, the metal hydrogen storage unit, the electrolyzer gas purification unit, the power electronic conversion unit and the electrolyzer alkaline solution cooling unit all release heat.

[0045] Reference Figure 2The blue line in the diagram indicates that the cooling signal of the electrolytic cell gas purification unit is activated, the chiller starts, and the inlet on the right side and the first outlet on the top side of the first solenoid valve V1 open. The system monitors the temperature of the electrolytic cell gas purification unit to control the opening of the first outlet on the top side of the first solenoid valve V1. The inlet and outlet of the chiller are connected to the inlet of the first solenoid valve V1 through pipes, and the first outlet of the first solenoid valve V1 is connected to the inlet of the electrolytic cell gas purification unit through pipes, thus enabling the chiller to supply cooling water to the electrolytic cell gas purification unit. The first inlet on the left side and the outlet on the bottom side of the second solenoid valve V2 open, and the outlet of the electrolytic cell gas purification unit is connected to the first inlet of the second solenoid valve V2 through pipes, and the outlet of the second solenoid valve V2 is connected to the inlet of the chiller through pipes, thus completing the cooling water circulation of the electrolytic purification unit.

[0046] Reference Figure 2 The red line in the diagram indicates that the cooling signal for the metal hydrogen storage unit is activated, the chiller starts, and the inlet on the right side and the second outlet on the lower side of the first solenoid valve V1 open. The outlet of the chiller is connected to the inlet of the first solenoid valve V1 via a pipe. Similarly, the inlet on the upper side and the first outlet on the left side of the third solenoid valve V3 open, while the second outlet on the right side closes. The system monitors the temperature of the metal hydrogen storage unit to control the opening of the first outlet on the left side of the third solenoid valve V3. The second outlet of the first solenoid valve V1 is connected to the inlet of the third solenoid valve V3 via a pipe. Finally, the first inlet on the right side and the first outlet on the left side of the fourth solenoid valve V4 open, while the second inlet on the upper side closes. The first outlet of the third solenoid valve V3 is connected to the first inlet of the fourth solenoid valve V4 via a pipe, and the outlet of the fourth solenoid valve V4 is connected to the inlet of the metal hydrogen storage unit via a pipe. This allows the chiller to provide cooling to the metal hydrogen storage unit. Water; the inlet on the left and the first outlet on the right of the fifth solenoid valve V5 are open, and the second outlet on the lower side is closed. The outlet of the metal hydrogen storage unit is connected to the inlet of the fifth solenoid valve V5 through a pipe; the first inlet on the left and the outlet on the right of the sixth solenoid valve V6 are open, and the second inlet on the upper side is closed. The first outlet of the fifth solenoid valve V5 is connected to the first inlet of the sixth solenoid valve V6 through a pipe. The outlet of the sixth solenoid valve V6 is connected to the inlet of the power electronic conversion unit through a pipe, thus enabling the metal hydrogen storage unit to supply cooling water to the power electronic conversion unit; the second inlet on the upper side and the outlet on the lower side of the second solenoid valve V2 are open. The outlet of the power electronic unit is connected to the second inlet of the second solenoid valve V2 through a pipe. The outlet on the lower side of the second solenoid valve V2 is connected to the inlet of the chiller through a pipe, thus completing the cooling water circulation between the metal hydrogen storage unit and the power electronic conversion unit.

[0047] Reference Figure 2In the purple circuit section, the first inlet on the left and the outlet above the seventh solenoid valve V7 are open. The first inlet of the seventh solenoid valve V7 receives room temperature tap water, and the outlet is connected to the inlet of the electrolytic cell's alkali cooling unit via a pipe. Similarly, the left inlet and right outlet of the eighth solenoid valve V8 are open. The outlet of the electrolytic cell's alkali cooling unit is connected to the inlet of the eighth solenoid valve V8 via a pipe, and the outlet of the eighth solenoid valve V8 is connected to the first inlet of the hot water storage tank via a pipe. At this time, the system monitors the water level signal of the hot water storage tank. When the water level reaches the maximum value, the first inlet on the left of the seventh solenoid valve V7 closes, and the second inlet on the right opens. The first outlet of the hot water storage tank is connected to the second inlet of the seventh solenoid valve V7 via a pipe, and the outlet of the seventh solenoid valve V7 is connected to the inlet of the electrolytic cell's alkali cooling unit via a pipe, supplying cooling water from the hot water storage tank to the electrolytic cell's alkali cooling unit. The system monitors the temperature of the electrolytic cell's alkali cooling unit to control the flow rate of the cooling water.

[0048] Figure 3 This is a schematic diagram of the fuel cell power generation process of the electrothermal hydrogen multi-energy system provided in this application embodiment. During the fuel cell power generation process, the power electronic conversion unit and the fuel cell unit release heat, while the metal hydrogen storage unit absorbs heat.

[0049] Reference Figure 3 In the red section, the cooling signal of the power electronic converter unit is activated, the chiller starts, and the inlet on the right side and the second outlet on the lower side of the first solenoid valve V1 open. The outlet of the chiller is connected to the inlet of the first solenoid valve V1 via a pipe. The inlet on the upper side and the second outlet on the right side of the third solenoid valve V3 open, while the first outlet on the left side closes. The system monitors the temperature of the power electronic converter unit to control the opening of the second outlet on the right side of the third solenoid valve V3. The second outlet of the first solenoid valve V1 is connected to the inlet of the third solenoid valve V3 via a pipe. The first inlet on the left side of the sixth solenoid valve V6 closes, while the upper... The second inlet on the side and the outlet on the right are opened. The second outlet of the third solenoid valve V3 is connected to the second inlet of the sixth solenoid valve V6 through a pipe. The outlet is connected to the inlet of the power electronic conversion unit through a pipe, so that the chiller can supply cooling water to the power electronic conversion unit. The first inlet on the left side of the second solenoid valve V2 is closed, and the second inlet on the upper side and the outlet on the lower side are opened. The outlet of the power electronic unit is connected to the second inlet of the second solenoid valve V2 through a pipe. The outlet on the lower side of the second solenoid valve V2 is connected to the inlet of the chiller through a pipe. Thus, the cooling water circulation of the power electronic conversion unit is completed.

[0050] Reference Figure 3In the purple section, the heating signal of the metal hydrogen storage unit is activated, opening the first inlet on the right and the lower outlet of the ninth solenoid valve V9. The second outlet of the hot water storage tank is connected to the first inlet of the ninth solenoid valve V9 via a pipe, and the outlet of the ninth solenoid valve V9 is connected to the inlet of the heat exchanger via a pipe, where heat exchange occurs. The second inlet on the upper side and the outlet on the left side of the fourth solenoid valve V4 are activated, while the first inlet on the right side is closed. The outlet of the heat exchanger is connected to the second inlet of the fourth solenoid valve V4 via a pipe, and the outlet of the fourth solenoid valve V4 is connected to the inlet of the metal hydrogen storage unit via a pipe, thus providing heat to the metal hydrogen storage unit. The first outlet on the right side of the fifth solenoid valve V5 is closed, while the inlet on the left side and the second outlet on the lower side are opened. The outlet of the metal hydrogen storage unit is connected to the inlet of the fifth solenoid valve V5 via a pipe.

[0051] The inlet on the upper side and the first outlet on the lower side of the tenth solenoid valve V10 are open, and the second outlet on the right side is closed. The second outlet of the fifth solenoid valve V5 is connected to the inlet of the tenth solenoid valve V10 through a pipe. The second inlet on the upper side and the outlet on the lower side of the ninth solenoid valve V9 are open. The first outlet of the tenth solenoid valve V10 is connected to the second inlet of the ninth solenoid valve V9 through a pipe. The outlet of the ninth solenoid valve V9 is connected to the inlet of the heat exchanger through a pipe, thereby realizing circulating heat exchange.

[0052] As heat exchange proceeds, the water temperature at the heat exchanger inlet gradually increases, leading to a decrease in heat exchange capacity. When the temperature rises to a certain level, it can no longer meet the heat dissipation requirements of the fuel cell unit. Therefore, it is necessary to inject circulating water into the hot water storage tank to utilize the new water flow for heat exchange. This can be achieved by monitoring the water temperature at the outlet of the metal hydrogen storage unit.

[0053] If the water temperature at the outlet of the metal hydrogen storage unit does not reach the set temperature of the hot water storage tank, the circulation will continue.

[0054] If the water temperature at the outlet of the metal hydrogen storage unit reaches the set temperature of the hot water storage tank, the inlet on the upper side and the second outlet on the right side of the tenth solenoid valve V10 will open, and the first outlet on the lower side will close. The second outlet of the tenth solenoid valve V10 will be connected to the second inlet of the hot water storage tank through a pipe, and heat exchange will take place in the hot water storage tank. The water in the hot water storage tank will flow back into the inlet of the heat exchanger from the second outlet through the ninth solenoid valve V9.

[0055] Thus, the heat released by the fuel cell unit during the fuel cell power generation process is used for the hydrogen release process of the metal hydrogen storage unit, realizing the cascade utilization of energy.

[0056] Furthermore, the water temperature in the hot water storage tank is monitored. If the water temperature in the hot water storage tank exceeds the set value, the second inlet on the lower side and the outlet on the right side of the eighth solenoid valve V8 are opened, while the first inlet on the left side is closed. The first inlet on the left side of the seventh solenoid valve V7 is opened to receive room temperature tap water, and the outlet on the lower side is connected to the second inlet of the eighth solenoid valve through a pipe to cool the hot water storage tank using room temperature tap water. The second inlet on the right side of the seventh solenoid valve V7 is opened and connected to the first outlet of the hot water storage tank through a pipe.

[0057] Combination Figure 2 and Figure 3 It can be seen that the hot water storage tank stores the waste heat of the alkaline cooling unit of the electrolyzer during the hydrogen production process of water electrolysis. The stored waste heat is used for the fuel cell power generation process, realizing the utilization of heat across time scales.

[0058] The water in the hot water storage tank is used for circulating cooling of the alkaline solution cooling unit in the electrolyzer during the hydrogen production process, thus improving the energy quality of the heat source within the tank. During fuel cell power generation, the water in the tank serves as the heat exchange medium for the metal hydrogen storage unit, circulating and exchanging heat with the fuel cell, further enhancing the energy quality of the heat source within the tank.

[0059] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A waste heat cascade utilization pipeline system for an electrothermal hydrogen multi-energy system, characterized in that, include: Electric hydrogen multi-energy system, chiller and hot water storage tank; The electrothermal hydrogen multi-energy system includes: an electrolyzer gas purification unit, an electrolyzer alkaline cooling unit, a power electronic conversion unit, a fuel cell unit, a heat exchanger, and a metal hydrogen storage unit; In the electrolysis hydrogen production process of the electrothermal hydrogen multi-energy system, the outlet of the chiller is connected to the inlet of the metal hydrogen storage unit and the gas purification unit of the electrolyzer via pipelines, providing cooling water to the metal hydrogen storage unit and the gas purification unit of the electrolyzer; the outlet of the metal hydrogen storage unit is connected to the inlet of the power electronic conversion unit via pipelines, providing cooling water to the power electronic conversion unit; room temperature tap water or the first outlet of the hot water storage tank is connected to the inlet of the alkaline solution cooling unit of the electrolyzer via pipelines, providing cooling water to the alkaline solution cooling unit of the electrolyzer; the first inlet of the hot water storage tank is connected to the outlet of the alkaline solution cooling unit of the electrolyzer via pipelines for waste heat storage; During the fuel cell power generation process of the electrothermal hydrogen multi-energy system, the outlet of the chiller is connected to the inlet of the power electronic conversion unit via a pipeline, providing cooling water to the power electronic conversion unit; the second outlet of the hot water storage tank is connected to the inlet of the heat exchanger via a pipeline, exchanging heat with the heat exchanger; the outlet of the heat exchanger is connected to the inlet of the metal hydrogen storage unit via a pipeline, providing heat to the metal hydrogen storage unit; the outlet of the metal hydrogen storage unit is directly connected to the inlet of the heat exchanger via a pipeline, exchanging heat with the heat exchanger, or the outlet of the metal hydrogen storage unit is connected to the inlet of the heat exchanger via the hot water storage tank via a pipeline, exchanging heat in the hot water storage tank.

2. The waste heat cascade utilization pipeline system of the electrothermal hydrogen multi-energy system according to claim 1, characterized in that, The waste heat cascade utilization pipeline system also includes multiple solenoid valves, which are used in the water electrolysis hydrogen production process: The outlet of the chiller is connected to the inlet of the first solenoid valve via a pipe, and the inlet of the chiller is connected to the outlet of the second solenoid valve via a pipe. The first outlet of the first solenoid valve is connected to the inlet of the gas purification unit of the electrolytic cell through a pipe, and the outlet of the gas purification unit of the electrolytic cell is connected to the first inlet of the second solenoid valve through a pipe. The second outlet of the first solenoid valve is connected to the inlet of the third solenoid valve via a pipe. The first outlet of the third solenoid valve is connected to the first inlet of the fourth solenoid valve via a pipe. The outlet of the fourth solenoid valve is connected to the inlet of the metal hydrogen storage unit via a pipe. The outlet of the metal hydrogen storage unit is connected to the inlet of the fifth solenoid valve via a pipe. The first outlet of the fifth solenoid valve is connected to the first inlet of the sixth solenoid valve via a pipe. The outlet of the sixth solenoid valve is connected to the inlet of the power electronic conversion unit via a pipe. The outlet of the power electronic conversion unit is connected to the second inlet of the second solenoid valve via a pipe.

3. The waste heat cascade utilization pipeline system of the electrothermal hydrogen multi-energy system according to claim 1 or 2, characterized in that, The chiller preferentially supplies cooling water to the gas purification unit of the electrolytic cell.

4. The waste heat cascade utilization pipeline system of the electrothermal hydrogen multi-energy system according to claim 1, characterized in that, The room temperature tap water or the first outlet of the hot water storage tank is connected to the inlet of the alkaline solution cooling unit of the electrolytic cell via a pipe, including: When the water level in the hot water storage tank does not reach the maximum water level, the room temperature tap water is connected to the inlet of the electrolytic cell alkali cooling unit through a pipe; or, When the water level in the hot water storage tank reaches the maximum water level, the outlet of the hot water storage tank is connected to the inlet of the alkaline solution cooling unit of the electrolytic cell through a pipe.

5. The waste heat cascade utilization pipeline system of the electrothermal hydrogen multi-energy system according to claim 4, characterized in that, The waste heat cascade utilization pipeline system also includes multiple solenoid valves; When the water level in the hot water storage tank does not reach the maximum water level, the first inlet of the seventh solenoid valve receives room temperature tap water, and the outlet of the seventh solenoid valve is connected to the inlet of the alkaline cooling unit of the electrolytic cell through a pipe; or, when the water level in the hot water storage tank reaches the maximum water level, the first inlet of the seventh solenoid valve is closed, the first outlet of the hot water storage tank is connected to the second inlet of the seventh solenoid valve through a pipe, and the outlet of the seventh solenoid valve is connected to the inlet of the alkaline cooling unit of the electrolytic cell through a pipe. The outlet of the alkali cooling unit of the electrolytic cell is connected to the inlet of the eighth solenoid valve through a pipe, and the outlet of the eighth solenoid valve is connected to the first inlet of the hot water storage tank through a pipe.

6. The waste heat cascade utilization pipeline system of the electrothermal hydrogen multi-energy system according to claim 1, characterized in that, The waste heat cascade utilization pipeline system also includes multiple solenoid valves, which are used during the fuel cell power generation process: The second outlet of the hot water storage tank is connected to the first inlet of the ninth solenoid valve via a pipe, and the outlet of the ninth solenoid valve is connected to the inlet of the heat exchanger via a pipe; the outlet of the heat exchanger is connected to the second inlet of the fourth solenoid valve via a pipe, and the outlet of the fourth solenoid valve is connected to the inlet of the metal hydrogen storage unit via a pipe.

7. The waste heat cascade utilization pipeline system of the electrothermal hydrogen multi-energy system according to claim 6, characterized in that, The outlet of the metal hydrogen storage unit is directly connected to the inlet of the heat exchanger via a pipeline, including: When the water temperature at the outlet of the metal hydrogen storage unit does not reach the set temperature of the hot water storage tank, the outlet of the metal hydrogen storage unit is connected to the inlet of the fifth solenoid valve through a pipe, and the second outlet of the fifth solenoid valve is connected to the inlet of the tenth solenoid valve through a pipe. The first outlet of the tenth solenoid valve is connected to the second inlet of the ninth solenoid valve via a pipe, and the outlet of the ninth solenoid valve is connected to the inlet of the heat exchanger via a pipe.

8. The waste heat cascade utilization pipeline system of the electrothermal hydrogen multi-energy system according to claim 6, characterized in that, The outlet of the metal hydrogen storage unit is connected to the inlet of the heat exchanger via a pipeline through the hot water storage tank, including: When the water temperature at the outlet of the metal hydrogen storage unit reaches the set temperature of the hot water storage tank, the outlet of the metal hydrogen storage unit is connected to the inlet of the fifth solenoid valve through a pipe, and the second outlet of the fifth solenoid valve is connected to the inlet of the tenth solenoid valve through a pipe. The second outlet of the tenth solenoid valve is connected to the second inlet of the hot water storage tank via a pipe. The second outlet of the hot water storage tank is connected to the first inlet of the ninth solenoid valve via a pipe, and the outlet of the ninth solenoid valve is connected to the inlet of the heat exchanger via a pipe.

9. The waste heat cascade utilization pipeline system of the electrothermal hydrogen multi-energy system according to claim 1, characterized in that, The heat stored in the hot water storage tank during the hydrogen production process via water electrolysis is used in the fuel cell power generation process.

10. The waste heat cascade utilization pipeline system of the electrothermal hydrogen multi-energy system according to claim 1, characterized in that, In the process of producing hydrogen through water electrolysis, the water in the hot water storage tank is used for circulating cooling of the alkaline solution cooling unit of the electrolyzer; in the process of generating electricity from the fuel cell, the water in the hot water storage tank serves as the heat exchange medium for the metal hydrogen storage unit, and circulates with the fuel cell unit in the heat exchanger for heat exchange.

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