Solid oxide hydrogen energy technology and chemical high-low energy coupling system

Abstract

The invention discloses a solid oxide hydrogen energy technology and chemical high-low energy coupling system. Steam generated by a chemical user is input into a solid oxide electrolytic tank to be electrolyzed to generate hydrogen and oxygen; hydrogen enters the tube bundle gas-liquid-gas generation and conversion device for heat exchange and then is cooled and supplied to a hydrogen user; saturated steam in the high-pressure gas-liquid separation device rises and enters the steam / gas heat exchange device; oxygen enters the steam / gas heat exchange device to exchange heat with saturated steam, and is supplied to an oxygen user after being cooled; the heated steam in the steam / gas heat exchange device enters the solid oxide electrolytic tank to enter the next cycle or enters the steam double-effect lithium bromide unit; cooling water generated by the steam double-effect lithium bromide unit enters a chemical user or is used for cooling oxygen and hydrogen for a hydrogen user and an oxygen user; the system has the advantages that energy gradient utilization and material flow closed circulation are achieved, energy is saved, and the energy utilization efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the field of solid oxide electrolysis hydrogen production, and in particular to a solid oxide hydrogen energy technology and chemical high and low energy coupling system. Background Art

[0002] Under the urgent situation of vigorously promoting energy transformation and actively responding to climate change around the world, it is urgent to find sustainable and clean energy solutions. Hydrogen energy has become the core energy source for building a low-carbon society in the future due to its high energy density and the fact that its only combustion product is water. Traditional hydrogen production by reforming fossil fuels, although mature in technology and low in cost, has large carbon emissions, which is contrary to emission reduction targets and difficult to meet the needs of sustainable development. In contrast, hydrogen production by electrolysis of water, especially the use of renewable energy to produce "green hydrogen" by electrolysis, has become a research focus in the energy field. For example, Chinese Patent Publication No. CN113137783A discloses a system and method for recovering waste heat from hydrogen production by electrolysis of water using a heat pump.

[0003] Solid oxide electrolyzer (SOEC) hydrogen production technology holds enormous potential and has attracted significant attention from research institutions and new energy companies. Derived from solid oxide fuel cells (SOFCs), SOECs share a similar stack structure and raw material system, with a single cell consisting of an anode, cathode, and electrolyte. The operating principle is the opposite of SOFCs. At high temperatures of 600-1000°C, a hydrogen electrode decomposes H2O, providing electrons to reduce oxygen ions, transforming the solid phase into a gas phase. At these high temperatures, the enthalpy of water vapor is high, allowing the electrolysis voltage to drop as low as 1.3V, significantly reducing power consumption compared to alkaline or proton exchange membrane (PEM) electrolysis, which typically requires voltages above 1.8V. At this minimum power consumption, 3kWh of electricity can produce one standard cubic meter of hydrogen. SOECs can efficiently convert waste heat into hydrogen production energy, particularly in high-temperature heat sources such as nuclear power plant waste heat and high-temperature industrial waste heat. This theoretically enables energy cascade utilization and improves energy efficiency.

[0004] In terms of energy cascade utilization, although SOEC hydrogen production technology has theoretical advantages, it faces many problems in practical application. At present, the precise matching of high-temperature heat sources and efficient conversion technology are still imperfect. Industrial production scenarios are complex and diverse, and heat source parameters fluctuate frequently. The existing SOEC system is difficult to respond quickly and adapt to changes in heat sources, resulting in a large amount of high-quality waste heat being lost in vain and unable to be fully converted into the energy required for hydrogen production, resulting in serious energy waste. At the same time, the system integration lacks a mature coordination mechanism. The SOEC hydrogen production system, heat source supply, and subsequent hydrogen energy application system are independent of each other, energy interaction is not smooth, information communication is hindered, and it is impossible to form an interlocking energy cascade utilization chain, which seriously restricts the improvement of overall energy utilization efficiency.

[0005] Closed-loop material flow and cascaded energy utilization are closely linked and are key to the large-scale commercialization of SOEC hydrogen production technology. During the hydrogen production process, material transformation and energy flow occur simultaneously. For example, when water vapor is produced by electrolysis, it is consumed as a raw material. However, if the unreacted water vapor can be properly recovered, it will not only reduce water waste but also achieve energy recovery through heat exchange. When this water vapor cools and condenses in the heat exchange equipment, the heat released can be used to preheat the feed gas entering the SOEC system or other processes requiring a low-temperature heat source, achieving cascaded energy utilization.

[0006] In summary, energy cascade utilization and closed-loop material flow are key issues that urgently need to be broken through in SOEC hydrogen production technology. Only by solving these problems can it be promoted from the demonstration and verification stage to large-scale commercial application, contributing to global energy transformation and sustainable development. Summary of the Invention

[0007] The technical problem to be solved by the present invention is how to realize energy cascade utilization and closed material flow circulation in the solid oxide hydrogen process, save energy and improve energy utilization efficiency.

[0008] The present invention solves the above-mentioned technical problems through the following technical means: a solid oxide hydrogen energy technology and chemical high and low energy coupling system, including a cooling water tank, a solid oxide electrolytic cell, a tube bundle gas-liquid gas conversion device, a high-pressure gas-liquid separation device, a steam / gas heat exchange device, a steam double-effect lithium bromide unit and a buffer water tank; steam generated by chemical users is input into the solid oxide electrolytic cell to generate hydrogen and oxygen through electrolysis; hydrogen enters the tube bundle gas-liquid gas conversion device for heat exchange, is cooled and supplied to hydrogen users; water in the cooling tank is transported to the tube bundle gas-liquid gas conversion device, is heated to become a gas-liquid mixture, and rises to the high-pressure gas-liquid separation device, and the saturated gas in the high-pressure gas-liquid separation device rises and enters the steam / gas heat exchange device; oxygen enters the steam / gas heat exchange device to exchange heat with saturated gas, and is supplied to oxygen users after being cooled; the gas heated in the steam / gas heat exchange device either enters the solid oxide electrolysis cell to enter the next cycle, or enters the steam double-effect lithium bromide unit to provide a heat source; the gas passing through the steam double-effect lithium bromide unit is converted into high-temperature condensed liquid and returned to the cooling water tank; the cooling water generated by the steam double-effect lithium bromide unit either enters chemical users, or cools oxygen and hydrogen for hydrogen users and oxygen users; the cooling water refluxed from the pipelines of hydrogen users and oxygen users is input into the buffer water tank, which sends the refluxed cooling water to the steam double-effect lithium bromide unit and then recycles it into the cooling water tank to enter the next cycle.

[0009] Furthermore, steam generated by chemical users is input into a solid oxide electrolysis cell to produce hydrogen and oxygen through electrolysis, including:

[0010] It is determined whether the temperature and flow rate of the steam generated by the chemical user meet the preset index requirements. If so, the steam is input into the solid oxide electrolysis cell through the first three-way regulating valve, and the solid oxide electrolysis cell produces oxygen and hydrogen through electrolysis.

[0011] Furthermore, the solid oxide hydrogen energy technology and chemical high and low energy coupling system also includes a steam temperature and flow detection unit, which detects the temperature and flow of steam generated by chemical users.

[0012] Furthermore, the hydrogen enters the tube bundle gas-liquid gas conversion device for heat exchange and is cooled and supplied to hydrogen users, including:

[0013] The hydrogen generated by the solid oxide electrolysis cell first enters the tube bundle gas-liquid gas conversion device to exchange heat with the water delivered by the high-pressure water pump. The hydrogen is cooled and enters the second cooler. After entering the second cooler, the hydrogen is cooled and supplied to hydrogen users.

[0014] Furthermore, the water from the cooling box is transported to the tube bundle gas-liquid gas conversion device, where it is heated to become a gas-liquid mixture, which rises to the high-pressure gas-liquid separation device. The saturated gas in the high-pressure gas-liquid separation device rises and enters the steam / gas heat exchange device, including:

[0015] The high-pressure water pump pumps water from the cooling box. The water input by the high-pressure water pump to the tube bundle gas-liquid gas conversion device is heated to become a gas-liquid mixture, and rises to the high-pressure gas-liquid separation device. The saturated gas in the high-pressure gas-liquid separation device rises and enters the steam / gas heat exchange device, and the liquid sinks back to the tube bundle gas-liquid gas conversion device to enter the next cycle.

[0016] Furthermore, the oxygen enters the steam / gas heat exchange device to exchange heat with the saturated steam, and is then cooled and supplied to oxygen users, including:

[0017] The oxygen generated by the solid oxide electrolysis cell enters the steam / gas heat exchange device, exchanges heat with the saturated steam, and then enters the first cooler after heat exchange, and is further cooled before being supplied to oxygen users.

[0018] Furthermore, the heated steam in the steam / gas heat exchange device enters the solid oxide electrolysis cell for the next cycle, or enters the steam double-effect lithium bromide unit to provide a heat source, including:

[0019] The heated steam in the steam / gas heat exchange device further increases its temperature and becomes slightly superheated steam, and then enters the solid oxide electrolysis through the steam three-way valve to enter the next cycle, or enters the steam double-effect lithium bromide unit to provide a heat source.

[0020] Furthermore, the steam from the double-effect steam lithium bromide unit is converted into high-temperature condensed liquid and returned to the cooling water tank; the cooling water generated by the double-effect steam lithium bromide unit is either fed into chemical users or used to cool oxygen and hydrogen for hydrogen and oxygen users, including:

[0021] The slightly superheated gas from the steam double-effect lithium bromide unit releases energy and turns into high-temperature condensed liquid, which flows back to the cooling water tank. The cooling water generated by the steam double-effect lithium bromide unit passes through the second three-way regulating valve and either enters the chemical user to provide a cold source, or enters the first cooler or the second cooler to cool the oxygen and hydrogen.

[0022] Furthermore, the cooling water returned from the pipelines of hydrogen users and oxygen users is input into the buffer water tank. The buffer water tank sends the returned cooling water to the steam double-effect lithium bromide unit and then recycles it into the cooling water tank to enter the next cycle, including:

[0023] The cooling water returned from the pipelines of oxygen users and hydrogen users through the first cooler and the second cooler respectively is input into the buffer water tank. The buffer water tank pumps the returned cooling water to the steam double-effect lithium bromide unit through a circulating water pump and then recovers it to the cooling water tank. The cooling water tank waits for the high-pressure water pump to pressurize it and enter the next cycle.

[0024] Furthermore, it also includes a cooling temperature detection unit, which is set on the pipeline between the second three-way regulating valve and the chemical user to detect the temperature of water entering the chemical user.

[0025] The advantages of the present invention are that, by adding a tube bundle gas-liquid-gas conversion device, the present invention fully utilizes the high-temperature, high-quality energy of the gas after decomposition in the solid oxide electrolytic cell. This not only provides energy for the decomposition of the solid oxide electrolytic cell, but also provides a heat source for the steam dual-effect lithium bromide unit and produces cooling water. On the one hand, it can cool hydrogen and oxygen gases and improve their purity, thereby effectively improving the quality of hydrogen / oxygen. On the other hand, the surplus cooling water can provide cooling water for chemical users. In addition, a sealed circulation system for high-quality energy recovery and utilization is added. High-pressure water is converted into gas through the tube bundle gas-liquid-gas conversion device. The gas enters the steam dual-effect lithium bromide unit and becomes condensate. The condensate is returned to the cooling water tank and pressurized by the high-pressure water pump to enter the next cycle, forming a sealed circulation system. This not only solves the water resource problem, but also recovers the low-grade energy of the condensate, achieving dual energy efficiency improvements in energy flow and material flow, ultimately achieving energy cascade utilization and closed material flow circulation, saving energy and improving energy utilization efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a structural schematic diagram of a solid oxide hydrogen energy technology and chemical high and low energy coupling system disclosed in an embodiment of the present invention. DETAILED DESCRIPTION

[0027] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0028] like Figure 1 As shown, the present invention provides a system for coupling solid oxide hydrogen energy technology with chemical high and low energy sources. The system comprises a cooling water tank 1, a high-pressure water pump 2, a solid oxide electrolytic cell 3, a tube bundle gas-liquid-gas conversion device 4, a high-pressure gas-liquid separation device 5, a steam / gas heat exchanger 6, a steam double-effect lithium bromide unit 7, a first three-way regulating valve 8, a first cooler 9, a second cooler 11, a cooling temperature detection unit 13, a steam temperature and flow detection unit 14, a buffer water tank 16, a circulating water pump 17, and a second three-way regulating valve 18. First, to facilitate understanding of the scheme, the aforementioned technical terms are explained: "High energy" in the "chemical high and low energy" refers to the generated steam, and "low energy" refers to the required cooling medium. The high-pressure water pump 2 can be a feed pump, a canned motor pump, or the like. The specific model is not specifically limited and can be selected as needed in actual applications. The tube bundle gas-liquid-gas conversion device 4 refers to a tubular heat exchanger, also known as a tubular heat exchanger. The specific model is not specifically limited and can be selected as needed in actual applications. High-pressure gas-liquid separation device 5 refers to a gas-liquid separator. The specific model is not particularly limited and can be selected as needed in actual applications. However, in the present invention, the application scenario is high-pressure medium, that is, gas-liquid separation of the high-pressure medium is performed, thus named high-pressure gas-liquid separation device 5. Steam / gas heat exchanger 6 also belongs to the heat exchanger category. The specific heat exchanger model is not particularly limited and can be selected as needed in actual applications. In the present invention, the application scenario of this heat exchanger is steam and hydrogen / oxygen, hence the name steam / gas heat exchanger 6. Steam double-effect lithium bromide unit 7 is fully known as steam double-effect lithium bromide absorption chiller, and can adopt relevant products provided by commercial suppliers.

[0029] The steam generated by the chemical user 15 is detected by the steam temperature and flow detection unit 14 to determine whether the temperature and flow meet the preset index requirements. If so, the steam is input into the solid oxide electrolysis cell 3 through the first three-way regulating valve 8, and the solid oxide electrolysis cell 3 produces oxygen and hydrogen through electrolysis.

[0030] The hydrogen generated by the solid oxide electrolysis cell 3 first enters the tube bundle gas-liquid-gas conversion device 4, where it undergoes heat exchange with water delivered by the high-pressure water pump 2. The hydrogen is cooled and then enters the second cooler 11. After entering the second cooler 11, the hydrogen is cooled and supplied to hydrogen users. The high-pressure water pump 2 pumps water from the cooling tank 1. The water supplied to the tube bundle gas-liquid-gas conversion device 4 is heated and converted into a vapor-liquid mixture, which then rises to the high-pressure gas-liquid separation device 5. The saturated vapor rises and enters the steam / gas heat exchanger 6, while the liquid sinks back to the tube bundle gas-liquid-gas conversion device 4 to enter the next cycle.

[0031] Oxygen generated by the solid oxide electrolysis cell 3 enters the steam / gas heat exchanger 6, where it exchanges heat with the saturated gas. After this heat exchange, it enters the first cooler 9 for further cooling before being supplied to oxygen users. The gas heated in the steam / gas heat exchanger 6 is further heated, becoming slightly superheated gas. It then passes through the steam three-way valve 8 and enters the solid oxide electrolysis cell 3 for the next cycle, or enters the steam double-effect lithium bromide generator 7 to provide a heat source.

[0032] The slightly superheated gas from the double-effect steam lithium bromide unit 7 releases energy and becomes a high-temperature condensed liquid, which then flows back to the cooling water tank 1. The cooling water generated by the double-effect steam lithium bromide unit 7 passes through a second three-way regulating valve 18 and either enters a chemical user to provide a cold source, or enters the first cooler 9 and the second cooler 11 to cool the oxygen and hydrogen. From the first cooler 9 and the second cooler 11, the cooling water flows back to the buffer water tank 16. The buffer water tank 16, via a circulating water pump 17, pumps the returned cooling water back to the double-effect steam lithium bromide unit 7 and then recycles it back to the cooling water tank 1. The cooling water tank 1 is pressurized by the high-pressure water pump 2 and enters the next cycle. A cooling temperature detection unit 13 is provided on the pipeline between the second three-way regulating valve 18 and the chemical user 15 to detect the temperature of the water entering the chemical user 15.

[0033] Through the above technical solution, this system fully utilizes the high-temperature, high-grade energy of the gas decomposed by the solid oxide electrolytic cell by adding a tube bundle gas-liquid gas conversion device 4. This not only provides energy for the solid oxide electrolytic cell decomposition, but also provides a heat source for the steam dual-effect lithium bromide unit 7 to produce cooling water. On the one hand, it can cool hydrogen and oxygen gases and improve their purity, thereby effectively improving the quality of hydrogen / oxygen. On the other hand, the surplus cooling water can provide cooling water for chemical users. This system adds a sealed circulation system for high-grade energy recovery and utilization. High-pressure water is converted into vapor through the tube bundle gas-liquid gas conversion device 4. The vapor enters the steam dual-effect lithium bromide unit 7 and becomes condensate. It returns to the cooling water tank 1 and is pressurized by the high-pressure water pump 2 to enter the next cycle, forming a sealed circulation system. This not only solves the water resource problem, but also recovers the low-grade energy of the condensate, achieving dual energy efficiency improvements in energy flow and material flow.

[0034] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A solid oxide hydrogen energy technology and chemical high and low energy coupling system, characterized in that: It includes a cooling water tank, a solid oxide electrolytic cell, a tube bundle gas-liquid gas conversion device, a high-pressure gas-liquid separation device, a steam / gas heat exchange device, a steam double-effect lithium bromide unit and a buffer water tank; the steam generated by the chemical user is input into the solid oxide electrolytic cell to produce hydrogen and oxygen through electrolysis; the hydrogen enters the tube bundle gas-liquid gas conversion device for heat exchange and is cooled and supplied to the hydrogen user; the water in the cooling tank is transported to the tube bundle gas-liquid gas conversion device, heated to become a gas-liquid mixture, and rises to the high-pressure gas-liquid separation device, and the saturated gas in the high-pressure gas-liquid separation device rises and enters the steam / gas heat exchange device; the oxygen enters the steam / gas heat exchange device and is cooled by the saturated gas. The steam is cooled and supplied to oxygen users after heat exchange; the steam heated in the steam / gas heat exchange device enters the solid oxide electrolytic cell to enter the next cycle, or enters the steam double-effect lithium bromide unit to provide a heat source; the steam passing through the steam double-effect lithium bromide unit is converted into high-temperature condensed liquid and returned to the cooling water tank; the cooling water generated by the steam double-effect lithium bromide unit enters chemical users, or is used to cool oxygen and hydrogen for hydrogen users and oxygen users; the cooling water refluxed from the pipelines where hydrogen users and oxygen users are located is input into the buffer water tank, which sends the reflux cooling water to the steam double-effect lithium bromide unit and then recycles it to the cooling water tank to enter the next cycle.

2. A solid oxide hydrogen energy technology and chemical high and low energy coupling system according to claim 1, characterized in that: The steam generated by chemical users is input into the solid oxide electrolysis cell to produce hydrogen and oxygen through electrolysis, including: It is determined whether the temperature and flow rate of the steam generated by the chemical user meet the preset index requirements. If so, the steam is input into the solid oxide electrolysis cell through the first three-way regulating valve, and the solid oxide electrolysis cell produces oxygen and hydrogen through electrolysis.

3. A solid oxide hydrogen energy technology and chemical high and low energy coupling system according to claim 2, characterized in that: It also includes a steam temperature and flow detection unit, which detects the temperature and flow of steam generated by chemical users.

4. The solid oxide hydrogen energy technology and chemical high and low energy coupling system according to claim 1 is characterized in that: The hydrogen enters the tube bundle gas-liquid gas conversion device for heat exchange and is cooled and supplied to hydrogen users, including: The hydrogen generated by the solid oxide electrolysis cell first enters the tube bundle gas-liquid gas conversion device to exchange heat with the water delivered by the high-pressure water pump. The hydrogen is cooled and enters the second cooler. After entering the second cooler, the hydrogen is cooled and supplied to hydrogen users.

5. A solid oxide hydrogen energy technology and chemical high and low energy coupling system according to claim 4, characterized in that: The water in the cooling box is transported to the gas-liquid gas conversion device of the tube bundle, where it is heated to become a gas-liquid mixture and then rises to the high-pressure gas-liquid separation device. The saturated gas in the high-pressure gas-liquid separation device rises and enters the steam / gas heat exchange device, which includes: The high-pressure water pump pumps water from the cooling box. The water input by the high-pressure water pump to the tube bundle gas-liquid gas conversion device is heated to become a gas-liquid mixture, and rises to the high-pressure gas-liquid separation device. The saturated gas in the high-pressure gas-liquid separation device rises and enters the steam / gas heat exchange device, and the liquid sinks back to the tube bundle gas-liquid gas conversion device to enter the next cycle.

6. A solid oxide hydrogen energy technology and chemical high and low energy coupling system according to claim 5, characterized in that: Oxygen enters the steam / gas heat exchanger to exchange heat with saturated steam, and is then cooled and supplied to oxygen users, including: The oxygen generated by the solid oxide electrolysis cell enters the steam / gas heat exchange device, exchanges heat with the saturated steam, and then enters the first cooler after heat exchange, and is further cooled before being supplied to oxygen users.

7. A solid oxide hydrogen energy technology and chemical high and low energy coupling system according to claim 6, characterized in that: The heated steam in the steam / gas heat exchange device enters the solid oxide electrolysis cell for the next cycle, or enters the steam double-effect lithium bromide unit to provide a heat source, including: The heated steam in the steam / gas heat exchange device further increases its temperature and becomes slightly superheated steam, and then enters the solid oxide electrolysis through the steam three-way valve to enter the next cycle, or enters the steam double-effect lithium bromide unit to provide a heat source.

8. A solid oxide hydrogen energy technology and chemical high and low energy coupling system according to claim 7, characterized in that: The steam from the double-effect steam lithium bromide unit is converted into high-temperature condensed liquid and returned to the cooling water tank; The cooling water generated by the steam double-effect lithium bromide unit is either used by chemical users or used to cool the oxygen and hydrogen for hydrogen users, including: The slightly superheated gas from the steam double-effect lithium bromide unit releases energy and turns into high-temperature condensed liquid, which flows back to the cooling water tank. The cooling water generated by the steam double-effect lithium bromide unit passes through the second three-way regulating valve and either enters the chemical user to provide a cold source, or enters the first cooler or the second cooler to cool the oxygen and hydrogen.

9. A solid oxide hydrogen energy technology and chemical high and low energy coupling system according to claim 8, characterized in that: The cooling water returned from the pipelines of hydrogen users and oxygen users is input into the buffer water tank. The buffer water tank sends the returned cooling water to the steam double-effect lithium bromide unit and then recycles it into the cooling water tank to enter the next cycle, including: The cooling water returned from the pipelines of oxygen users and hydrogen users through the first cooler and the second cooler respectively is input into the buffer water tank. The buffer water tank pumps the returned cooling water to the steam double-effect lithium bromide unit through a circulating water pump and then recovers it to the cooling water tank. The cooling water tank waits for the high-pressure water pump to pressurize it and enter the next cycle.

10. The solid oxide hydrogen energy technology and chemical high and low energy coupling system according to claim 8, characterized in that: It also includes a cooling temperature detection unit, which is set on the pipeline between the second three-way regulating valve and the chemical user to detect the temperature of water entering the chemical user.

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