Solid oxide electrolytic cell hydrogen production system coupled with heat pump

Abstract

The utility model discloses a solid oxide electrolytic cell hydrogen production system coupled with a heat pump, which comprises an SOEC (solid oxide electrolytic cell) module, an SOEC (solid oxide electrolytic cell) module, an SOEC module, an SOEC module, an SOEC module, an SOEC module, an SOEC module, an SOEC module, an SOEC module and an SOEC module, the heat pump module comprises a heat pump compressor, a condenser, an expansion valve and an evaporator which form a loop; the cathode connection section and the anode connection section both flow through the evaporator and conduct heat exchange with the evaporator, the cathode connection section is connected with a gas-liquid separation device after flowing through the evaporator, the gas-liquid separation device is connected with a hydrogen pipe and a condensation pipe, and the condensation pipe flows through the condenser and conducts heat exchange with the condenser. And the condensation pipe is connected with the water vapor access section after flowing through the condenser. According to the utility model, the energy consumption of the heat pump module can be reduced by utilizing tail heat, and pure water is recycled, so that the cyclic utilization of energy and substances is realized, the hydrogen production cost is greatly reduced, and the popularization of hydrogen energy is facilitated.

Description

Technical Field

[0001] This utility model relates to the technical field of hydrogen energy, and in particular to a hydrogen production system using a solid oxide electrolysis cell coupled with a heat pump. Background Technology

[0002] Solid oxide electrolysis (SOEC) is a high-efficiency hydrogen production technology that uses external electricity to electrolyze water vapor to produce hydrogen. Compared to alkaline electrolyzers and proton exchange membrane electrolyzers, SOEC offers advantages such as faster reaction speeds, higher hydrogen production efficiency, and lower power consumption. SOEC can utilize renewable energy sources like solar and wind power to produce hydrogen, converting excess electricity into hydrogen for storage, thus serving as an important supplement to the energy mix. However, several issues currently exist in the application of SOEC hydrogen production technology:

[0003] 1. According to the working principle of SOEC, room temperature water needs to be heated to the target temperature to produce steam, and then the steam is decomposed into hydrogen and oxygen through electrolysis. The entire process consumes a lot of energy, which is not conducive to improving the efficiency of SOEC electrolysis hydrogen production system.

[0004] 2. SOEC cathode gas has a high temperature and high water content. In order to obtain high-concentration hydrogen, condensation equipment is required to remove water. However, the low-quality heat energy of SOEC cathode gas released by the condensation equipment is not fully utilized before being discharged, resulting in energy waste. Utility Model Content

[0005] The present invention aims to provide a hydrogen production system using a solid oxide electrolysis cell coupled with a heat pump, in order to solve the problem of excessively high hydrogen production costs in the prior art.

[0006] A solid oxide electrolysis cell hydrogen production system with coupled heat pump according to a first aspect embodiment of the present invention includes:

[0007] The SOEC module has an air inlet section and a water vapor inlet section at its input end, and a cathode connection section and an anode connection section at its output end.

[0008] A heat pump module includes a heat pump compressor, a condenser, an expansion valve, and an evaporator forming a circuit. The heat pump compressor outputs high-temperature refrigerant to the condenser, and the expansion valve outputs low-temperature refrigerant to the evaporator. Both the cathode connection section and the anode connection section flow through the evaporator and exchange heat with it. After flowing through the evaporator, the cathode connection section is connected to a gas-liquid separator. The gas-liquid separator is connected to a hydrogen pipe and a condenser pipe. The condenser pipe flows through the condenser and exchanges heat with it. After flowing through the condenser, the condenser pipe is connected to a water vapor inlet section.

[0009] The solid oxide electrolysis cell hydrogen production system of the coupled heat pump according to the embodiments of this utility model has at least the following beneficial effects: The SOEC module can electrolyze high-temperature water vapor into hydrogen and oxygen, wherein oxygen is discharged from the anode connection section and water-containing hydrogen is discharged from the cathode connection section. Both the anode and cathode connection sections have a certain amount of residual heat. After passing through the evaporator, the anode and cathode connection sections exchange heat with the low-temperature refrigerant. The low-temperature refrigerant in the evaporator absorbs heat and vaporizes, then flows back to the heat pump compressor for internal circulation to increase the exhaust temperature of the heat pump compressor. Simultaneously, the anode and cathode connection sections release heat and condense. This utility model utilizes the residual heat of the SOEC module to reduce the energy consumption of the heat pump module; the water vapor in the cathode connection section condenses into condensate after heat exchange, and the gas... After the liquid-gas mixture passes through the gas-liquid separator, hydrogen flows towards the hydrogen pipe for easy collection, while condensate flows towards the condenser pipe. The condensate in the condenser pipe exchanges heat with the high-temperature refrigerant after passing through the condenser. The condensate absorbs heat, vaporizes, and reverts to water vapor, which is then circulated to the water vapor inlet section of the SOEC module. Since the SOEC module requires pure water as its steam source, and the cathode connection section contains only water vapor and hydrogen without other impurities, the circulated water vapor can be directly used in the SOEC module, saving pure water resources. Compared with existing technologies, this invention not only utilizes tail heat to reduce the energy consumption of the heat pump module but also recycles pure water, achieving energy and material recycling, significantly reducing the cost of hydrogen production, and promoting the use of hydrogen energy.

[0010] According to some embodiments of the present invention, in order to supply condensate to the condenser, the condenser pipe is connected to a condensate pump.

[0011] According to some embodiments of this utility model, the hydrogen production system of the solid oxide electrolysis cell coupled with the heat pump further includes a water supply pipe, which is connected to the condenser pipe. Since some water vapor generates hydrogen and oxygen during the electrolysis reaction, pure water needs to be supplied from an external source for the long-term operation of the hydrogen production system.

[0012] According to some embodiments of this utility model, the condenser is located in a water tank, and both the water supply pipe and the condenser pipe are connected to the water tank. With the above arrangement, pure water is heated in the water tank to generate water vapor, and the water vapor flows towards the water vapor inlet section.

[0013] According to some embodiments of this utility model, the water supply pipe is connected to a solenoid valve, and the opening degree of the solenoid valve is adjustable. By adjusting the supply of pure water, the progress of the electrolysis reaction can be controlled.

[0014] According to some embodiments of this utility model, in order to supply pure water to the condenser, the water supply pipe is connected to a water pump.

[0015] According to some embodiments of this utility model, the condenser tube is connected to a steam compressor after flowing through the condenser, and the steam compressor is connected to the steam inlet section. The steam compressor is used to increase the pressure and temperature of the steam, prevent the steam from condensing, and ensure a stable steam supply.

[0016] According to some embodiments of this invention, the anode connection section is connected to an oxygen pipe after flowing through the evaporator. The cooled oxygen flows towards the oxygen pipe to facilitate oxygen collection.

[0017] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0018] The above and / or additional aspects and advantages of this utility model will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0019] Figure 1 This is a schematic diagram of the structure of the solid oxide electrolysis cell hydrogen production system with coupled heat pump provided in this embodiment of the utility model;

[0020] Figure 2 This is a schematic diagram of the structure of the heat pump module provided in this embodiment of the utility model.

[0021] In the attached diagram: 100-SOEC module, 200-heat pump module, 110-steam inlet section, 120-air inlet section, 130-cathode connection section, 140-anode connection section, 210-heat pump compressor, 220-condenser, 230-liquid storage tank, 240-filter, 250-expansion valve, 260-evaporator, 270-gas-liquid separator, 310-gas-liquid separation device, 320-hydrogen pipe, 330-condenser pipe, 420-oxygen pipe, 340-condensate pump, 500-steam compressor, 600-makeup water pipe, 610-feed water pump, 620-solenoid valve. Detailed Implementation

[0022] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0023] In the description of this utility model, it should be understood that the directional descriptions, such as up, down, front, back, left, right, etc., indicate the directional or positional relationship based on the directional or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0024] In the description of this utility model, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. If "first" or "second" is used in the description, it is only for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0025] In the description of this utility model, unless otherwise explicitly defined, terms such as "setting," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this utility model in conjunction with the specific content of the technical solution.

[0026] like Figure 1 As shown, the hydrogen production system of a solid oxide electrolyzer coupled with a heat pump according to a first aspect embodiment of the present invention includes an SOEC module 100 and a heat pump module 200. The SOEC module 100 is a solid oxide fuel cell that operates in reverse. Under applied voltage and high temperature, it electrolyzes water vapor to produce hydrogen and oxygen, thereby converting electrical and thermal energy into chemical energy. In the SOEC module 100, by utilizing external electrical energy, water vapor near the cathode is electrolyzed into hydrogen and oxygen ions at a temperature above 650°C. Due to the material limitations of the battery cells, only oxygen ions are allowed to migrate from the cathode to the anode. In the anode, the oxygen ions release electrons through the oxygen evolution reaction to form oxygen gas. Therefore, the cathode gas of the SOEC module 100 contains no impurities other than water vapor and hydrogen.

[0027] However, the SOEC module 100 has high requirements for steam and needs to use deionized water as raw material, i.e., pure water. Therefore, pure water production equipment also needs to be configured in the related supporting equipment. Furthermore, in addition to the steam inlet section 110 at the input end, the SOEC module 100 also has an air inlet section 120. Air in the SOEC module 100 is heated by the high-temperature exhaust gas from the anode of the electrolytic cell through a heat exchanger, thus heating the electrolytic cell together with the steam inlet section 110, ensuring uniform temperature in the electrolytic cell. In addition to heating the electrolytic cell, the function of the air inlet also includes balancing the pressure of the anode and cathode and transporting the oxygen produced in the electrolytic cell.

[0028] Furthermore, the SOEC module 100 has a cathode connection section 130 and an anode connection section 140 at its output. Oxygen produced by electrolysis is discharged from the anode connection section 140, and hydrogen produced by electrolysis is discharged from the cathode connection section 130. Since water vapor is electrolyzed at the cathode, any water vapor not involved in the electrolysis is discharged from the cathode connection section 130 as well. Therefore, the hydrogen discharged from the cathode connection section 130 is rich in water vapor and needs to be dehydrated in the next process step to obtain high-concentration hydrogen.

[0029] Since the electrolysis reaction takes place under high-temperature conditions, the gas inside both the anode connection section 140 and the cathode connection section 130 retains a certain amount of residual heat. If this heat is allowed to be filtered and discharged, not only will a large amount of heat energy be lost, but also a large amount of pure water resources will be lost. Therefore, this invention introduces a heat pump module 200. The heat pump module 200 is a steam heat pump, which consumes more energy than ordinary household heat pumps. The refrigerant temperature in the condenser 220 can heat the water to boiling point, thus heating the liquid water into steam.

[0030] like Figure 2As shown, the heat pump module 200 mainly consists of a heat pump compressor 210, a condenser 220, a liquid receiver 230, a filter 240, an expansion valve 250, an evaporator 260, and a gas-liquid separator 270. These components are connected sequentially to form a circulation loop. Gaseous refrigerant in the gas-liquid separator 270 is drawn into the suction port of the heat pump compressor 210. The heat pump compressor 210 compresses the gaseous refrigerant through a cylinder, thereby outputting high-temperature, high-pressure gaseous refrigerant to the condenser 220. As the high-temperature, high-pressure gaseous refrigerant flows through the condenser 220, it exchanges heat with cold water, at which point the high-temperature, high-pressure gaseous refrigerant liquefies and releases heat, becoming a room-temperature, high-pressure liquid refrigerant. The liquid receiver 230 provides a buffer space to prevent abnormal pressure and protect the normal operation of the heat pump module 200, while the filter 240 filters impurities in the refrigerant to prevent them from participating in the internal circulation of the refrigerant. The expansion valve 250 has a capillary tube several meters long, which can convert the room temperature, high pressure liquid refrigerant passing through it into a low temperature, low pressure liquid refrigerant. The low temperature, low pressure liquid refrigerant exchanges heat with the outside air when flowing through the evaporator 260. At this time, the low temperature, low pressure liquid refrigerant vaporizes and absorbs heat to become a room temperature, low pressure gaseous refrigerant. Since the heat pump compressor 210 cannot compress the liquid refrigerant, a gas-liquid separator 270 needs to be installed upstream of the suction port of the heat pump compressor 210 to prevent the liquid refrigerant from being sucked into the cylinder of the heat pump compressor 210. When the gas-liquid mixed refrigerant enters the gas-liquid separator 270, the gas-liquid separator 270 uses the difference in density between the gas and the liquid to separate the gas and liquid by increasing the pipe diameter to reduce the speed and changing the direction of the speed. The gaseous refrigerant is drawn into the heat pump compressor 210, while the liquid refrigerant is left in the gas-liquid separator 270 to gradually transform into gaseous refrigerant.

[0031] Therefore, it can be seen that the heat pump module 200 mainly exchanges heat with the external medium through the condenser 220 and the evaporator 260. Figure 1 As shown, this invention utilizes the working principle of a heat pump, allowing both the cathode connection section 130 and the anode connection section 140, which have low-grade heat energy, to flow through the evaporator 260. Since the heat energy provided by the cathode connection section 130 and the anode connection section 140 is higher than that provided by the ambient temperature, the refrigerant in the evaporator 260 can be transformed into a higher-temperature gaseous refrigerant after heat exchange with the cathode connection section 130 and the anode connection section 140. With the power of the heat pump compressor 210 remaining constant, the higher the temperature of the return refrigerant, the higher the temperature of the exhaust refrigerant. In other words, with the exhaust refrigerant temperature remaining constant, the higher the temperature of the return refrigerant, the less power the heat pump compressor 210 requires. Through the above setup, this invention utilizes the residual heat of the SOEC module 100 to reduce the energy consumption of the heat pump module 200.

[0032] On the other side, water vapor in the cathode connection section 130 condenses into condensate after heat exchange. The cathode tail gas section, after flowing through the evaporator 260, is connected to a gas-liquid separator 310. The gas-liquid separator 310 is connected to a hydrogen pipe 320 and a condenser pipe 330. The working principle of the gas-liquid separator 310 is similar to that of the gas-liquid separator 270 mentioned above, but the gas-liquid separator 310 no longer stores liquid; the liquid flows towards the condenser pipe 330, and the gas flows towards the hydrogen pipe 320. Since the cathode gas of the SOEC module 100 contains no impurities other than water vapor and hydrogen, the gas in the hydrogen pipe 320 is high-concentration hydrogen, and the liquid in the condenser pipe 330 is pure water. Similarly, the anode tail gas section, after flowing through the evaporator 260, is connected to an oxygen pipe 420. The high-temperature oxygen releases heat after heat exchange with the evaporator 260, becoming room-temperature oxygen, and flows towards the oxygen pipe 420.

[0033] Since the pure water in the condenser tube 330 can be recycled, this invention installs a condensate pump 340 on the condenser tube 330 so that the water flows through the condenser 220. After flowing through the condenser 220, the condenser tube 330 connects to the steam inlet section 110. The condensate pump 340 is used to transport the pure water in the condenser tube 330 to the condenser 220. After exchanging heat with the refrigerant in the condenser 220, the pure water in the condenser tube 330 absorbs heat and vaporizes into water vapor. This water vapor is recycled to the steam inlet section 110 to participate in the next round of electrolysis reaction. Compared with the prior art, this invention, in addition to utilizing tail heat to reduce the energy consumption of the heat pump module 200, also recycles pure water to achieve the recycling of energy and materials, significantly reducing the cost of hydrogen production and promoting the use of hydrogen energy.

[0034] In some embodiments of this utility model, in order to prevent water vapor from condensing, a steam compressor 500 is provided between the condenser pipe 330 and the water vapor inlet section 110. The steam compressor 500 is used to compress the water vapor. After compression, the temperature and pressure of the water vapor are significantly increased to accelerate the flow of water vapor and prevent the water vapor from condensing during the flow, thus ensuring a stable steam supply.

[0035] In some embodiments of this invention, since some water vapor generates hydrogen and oxygen during the electrolysis reaction, pure water needs to be replenished from the outside for the long-term operation of the hydrogen production system. Therefore, the solid oxide electrolysis cell hydrogen production system coupled with a heat pump also includes a water supply pipe 600, which is connected to the condenser pipe 330. Specifically, the water supply pipe 600 is connected to a feed water pump 610, which is used to transport the pure water in the water supply pipe 600 to the outside. To improve heat exchange efficiency, both the water supply pipe 600 and the condenser pipe 330 are connected to a water tank located outside the condenser 220. Pure water is collected in both the water supply pipe 600 and the condenser pipe 330 in the water tank. The pure water gradually vaporizes into water vapor under the heating of the condenser 220. The water vapor flows towards the steam compressor 500 under the negative pressure of the steam compressor 500 and is finally transported by the steam compressor 500 to the water vapor inlet section 110.

[0036] Furthermore, to facilitate control of the electrolysis reaction process, the water supply pipe 600 is connected to a solenoid valve 620, the opening of which is adjustable. This invention regulates the supply of pure water by adjusting the opening of the solenoid valve 620, thereby controlling the amount of water vapor generated and ultimately controlling the electrolysis reaction process. Since the hydrogen production system of the solid oxide electrolysis cell coupled with the heat pump requires a relatively long preheating time during startup, it is generally not easily shut down except in emergencies. To balance peak and trough electricity consumption and absorb excess electricity from the grid, the supply of pure water is increased during off-peak periods to convert more electrical energy into hydrogen energy, while the supply of pure water is reduced during peak periods to decrease the load on the grid.

[0037] The embodiments of the present utility model have been described in detail above with reference to the accompanying drawings. However, the present utility model is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present utility model.

Claims

1. A solid oxide electrolysis cell hydrogen production system coupled with a heat pump, characterized in that, include: The SOEC module (100) has an air inlet section (120) and a water vapor inlet section (110) at its input end, and a cathode connection section (130) and an anode connection section (140) at its output end. A heat pump module (200) includes a heat pump compressor (210), a condenser (220), an expansion valve (250), and an evaporator (260) forming a circuit. The heat pump compressor (210) outputs high-temperature refrigerant to the condenser (220), and the expansion valve (250) outputs low-temperature refrigerant to the evaporator (260). The cathode connection section (130) and the anode connection section (140) both flow through the evaporator (260) and interact with the evaporator (260). Heat exchange is performed. The cathode connection section (130) is connected to a gas-liquid separator (310) after flowing through the evaporator (260). The gas-liquid separator (310) is connected to a hydrogen pipe (320) and a condenser pipe (330). The condenser pipe (330) flows through the condenser (220) and exchanges heat with the condenser (220). After flowing through the condenser (220), the condenser pipe (330) is connected to the water vapor inlet section (110).

2. The hydrogen production system for a solid oxide electrolyzer with coupled heat pump according to claim 1, characterized in that: The condenser tube (330) is connected to a condensate pump (340).

3. The solid oxide electrolysis cell hydrogen production system with coupled heat pump according to claim 1, characterized in that: It also includes a water supply pipe (600) connected to the condenser pipe (330).

4. The solid oxide electrolysis cell hydrogen production system with coupled heat pump according to claim 3, characterized in that: The condenser (220) is located in the water tank, and the water supply pipe (600) and the condenser pipe (330) are both connected to the water tank.

5. The solid oxide electrolysis cell hydrogen production system with coupled heat pump according to claim 3, characterized in that: The water supply pipe (600) is connected to a solenoid valve (620), and the opening degree of the solenoid valve (620) is adjustable.

6. The solid oxide electrolysis cell hydrogen production system with coupled heat pump according to claim 3, characterized in that: The water supply pipe (600) is connected to a water supply pump (610).

7. The solid oxide electrolysis cell hydrogen production system with coupled heat pump according to claim 1, characterized in that: The condenser tube (330) is connected to a steam compressor (500) after flowing through the condenser (220), and the steam compressor (500) is connected to the steam inlet section (110).

8. The solid oxide electrolysis cell hydrogen production system with coupled heat pump according to claim 1, characterized in that: The anode connection section (140) is connected to an oxygen pipe (420) after flowing through the evaporator (260).

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