An ammonia synthesis device based on a solid oxide electrolytic cell

Abstract

The present invention provides a synthetic ammonia device based on a solid oxide electrolytic cell, which belongs to the technical field of solid oxide electrolytic cells and solves the problems of high cost and high power consumption of ammonia production in the existing SOEC system. The device includes a SOEC stack, a fan, an electric heater, a steam generator, heat exchangers one to three and an ammonia synthesizer. Among them, the fan, the electric heater, and the branch one of the heat exchanger one are connected in sequence to obtain high-temperature air to the air inlet of the SOEC stack; the water vapor obtained by the steam generator enters the branch one of the heat exchanger two for the first stage heat exchange, and then enters the branch two of the heat exchanger one to perform the second stage heat exchange with the above-mentioned high-temperature air to obtain high-temperature water vapor to the fuel inlet of the SOEC stack; the fuel tail gas output by the SOEC stack enters the branch two of the heat exchanger two for the first stage heat exchange, and then enters the branch one of the heat exchanger three to perform the second stage heat exchange with the gas of the branch two of the heat exchanger three, and obtains a mixed gas of high-temperature hydrogen and water vapor to be transported to the ammonia synthesizer.

Description

Technical Field

[0001] The present invention relates to the technical field of solid oxide electrolytic cells, and in particular to an ammonia synthesis device based on a solid oxide electrolytic cell. Background Art

[0002] Ammonia can be used in the production of chemical fertilizers and chemical fibers, refrigeration and other fields, or as a clean fuel.

[0003] At present, there are mainly three methods for synthesizing ammonia. The first is to synthesize ammonia using chemical energy sources such as coal and natural gas, which has high carbon emissions and heavy pollution. The second is the ammonia synthesis method using the condensation method in industry. Limited by the reversible reaction of ammonia synthesis and the gas-liquid equilibrium of each component of the synthesis gas, this scheme cannot completely separate ammonia, and separation needs to be carried out at a sufficiently low temperature (controlled below -5°C) to ensure that the ammonia content in the reflux gas is below 3%. The third is ammonia production by the SOEC system. The SOEC system has two sets of electric heaters for hydrogen production and ammonia synthesis respectively, making the cost and power consumption of the system relatively high. Moreover, the high-temperature tail gas on the air side is not reasonably utilized, resulting in an energy loss. Ammonia synthesis also requires additional water injection, and the mixture of hydrogen and water needs to be electrically heated, posing a safety hazard. Summary of the Invention

[0004] In view of the above analysis, an embodiment of the present invention aims to provide an ammonia synthesis device based on a solid oxide electrolytic cell to solve the problem of high cost and power consumption of ammonia production by the existing SOEC system.

[0005] On the one hand, an embodiment of the present invention provides an ammonia synthesis device based on a solid oxide electrolytic cell, which is characterized by including an SOEC stack, a fan, an electric heater, a steam generator, heat exchangers I - III, and an ammonia synthesizer; wherein,

[0006] The fan, the electric heater, and the first branch of heat exchanger I are connected in sequence to obtain high-temperature air to the air inlet of the SOEC stack;

[0007] The water vapor obtained by the steam generator enters the first branch of heat exchanger II for the first-stage heat exchange, and then enters the second branch of heat exchanger I to perform the second-stage heat exchange with the above high-temperature air to obtain high-temperature water vapor to the fuel inlet of the SOEC stack;

[0008] The fuel electrode tail gas output by the SOEC stack enters the second branch of heat exchanger II for the first-stage heat exchange, and then enters the first branch of heat exchanger III to perform the second-stage heat exchange with the gas in the second branch of heat exchanger III to obtain a mixed gas of high-temperature hydrogen and water vapor, which is transported to the ammonia synthesizer.

[0009] The beneficial effects of the above technical solution are as follows: Compared with the prior art, it is not necessary to directly heat the mixture of hydrogen and water vapor, and the gas electrode side electric heater and the two electric heaters before ammonia synthesis in the prior art are cancelled. Instead, air is heated by electricity, and then the high-temperature air exchanges heat with normal-temperature water vapor to realize water vapor heating. Then, the high-temperature mixed gas of hydrogen and water vapor in the fuel electrode tail gas of the SOEC is used to exchange heat with the gas in branch two of heat exchanger three (i.e., nitrogen or the gas used for directly heating or indirectly heating nitrogen), so as to solve the temperature and humidity conditions required for ammonia synthesis from the source. Through effective thermal management, the potential safety hazards brought about by the electric heating of hydrogen and water vapor are avoided. The conditions required for ammonia synthesis can be accurately controlled through the heat exchanger, which can improve the synthesis efficiency. Moreover, only one electric heater is used to provide heat energy for the whole system, reducing components, lowering costs, and simplifying the control difficulty of thermal management, thus greatly reducing the cost and power consumption of the ammonia synthesis device.

[0010] Based on the further improvement of the above device, the gas in branch two of heat exchanger three is nitrogen at normal temperature and preset pressure;

[0011] The nitrogen enters branch two of heat exchanger three and exchanges heat with the mixed gas of high-temperature hydrogen and water vapor in branch one thereof, and then the nitrogen at high temperature and preset pressure is obtained and transported to the ammonia synthesizer.

[0012] The beneficial effects of the above improvement scheme are as follows: The nitrogen at normal temperature and preset pressure is directly heated by heat exchanger three, reducing components, lowering costs, and simplifying the control difficulty of thermal management.

[0013] Furthermore, the ammonia synthesis device based on the solid oxide electrolytic cell further includes mixer one; and,

[0014] The gas in branch two of heat exchanger three is the fuel electrode tail gas output by the SOEC stack;

[0015] One input end of mixer one inputs nitrogen at normal temperature and preset pressure, the second input end is connected to the output end of branch two of heat exchanger three, and the output end is connected to the input end of the ammonia synthesizer, so that the high-temperature mixed gas of nitrogen and fuel electrode tail gas is obtained and transported to the ammonia synthesizer.

[0016] The beneficial effects of the above improvement scheme are as follows: Mixer one is added, and the nitrogen is mixed and heated by the high-temperature mixed gas (hydrogen and water vapor) of the fuel electrode output by heat exchanger three, so that the high-temperature mixed gas of nitrogen and fuel electrode tail gas is obtained and transported to the ammonia synthesizer for ammonia synthesis, realizing the control of the temperature and humidity of nitrogen.

[0017] Furthermore, the ammonia synthesis device based on the solid oxide electrolytic cell further includes heat exchanger four; and,

[0018] The gas in branch two of the third heat exchanger is the fuel electrode tail gas or the air electrode tail gas or the air electrode tail gas output by the SOEC stack;

[0019] In branch one of the fourth heat exchanger, nitrogen gas at room temperature and a preset pressure is input. The input end of branch two is connected to the output end of branch two of the third heat exchanger. The output ends of branch one and branch two are both connected to the input end of the ammonia synthesizer, so that the obtained high-temperature nitrogen gas and the mixed gas of high-temperature hydrogen gas and water vapor are respectively transported to the ammonia synthesizer.

[0020] The beneficial effects of the above improvement scheme are as follows: The fourth heat exchanger is added. The fuel electrode high-temperature tail gas or the air electrode high-temperature tail gas output by the third heat exchanger indirectly heats the nitrogen gas at room temperature and a preset pressure in the fourth heat exchanger, realizing thermal management control.

[0021] Furthermore, the ammonia synthesis device based on the solid oxide electrolytic cell further includes a three-way valve and a mixer two; among them,

[0022] The three-way valve is arranged at the front end of the fourth heat exchanger. The input end inputs nitrogen gas at room temperature and a preset pressure. Output end one is connected to the input end of branch one of the fourth heat exchanger, and output end two is connected to the input end two of the mixer two;

[0023] The mixer two is arranged between the fourth heat exchanger and the ammonia synthesizer. Its input end one is connected to the output end of branch one of the fourth heat exchanger, and the output end is connected to the input end of the ammonia synthesizer, so that the obtained high-temperature nitrogen gas is transported to the ammonia synthesizer.

[0024] The beneficial effects of the above improvement scheme are as follows: After adding the three-way valve and the mixer two, by mixing the room-temperature nitrogen gas and the high-temperature nitrogen gas, the heating of the nitrogen gas is realized.

[0025] Furthermore, the ammonia synthesis device based on the solid oxide electrolytic cell further includes a nitrogen gas storage cylinder and a booster pump connected in sequence;

[0026] The output end of the booster pump is connected to the input end of branch two of the third heat exchanger, or the input end one of the mixer one, or the input end of the three-way valve, and is used for transporting the output nitrogen gas at room temperature and a preset pressure to the input end of branch two of the third heat exchanger, or the input end one of the mixer one, or the input end of the three-way valve.

[0027] The beneficial effects of the above improvement scheme are as follows: Under the action of the booster pump, nitrogen gas provides the pressure environment required for ammonia synthesis, improving the efficiency of ammonia synthesis.

[0028] Furthermore, the ammonia synthesis device based on the solid oxide electrolytic cell further includes a water tank and a water pump connected in sequence; among them,

[0029] The output end of the water pump is connected to the water inlet of the steam generator.

[0030] The beneficial effects of the above improvement scheme are as follows: By controlling the water vapor content with a water pump, the humidity condition required for synthesizing ammonia is solved from the source, and the efficiency of ammonia synthesis is improved.

[0031] Furthermore, the ammonia synthesis device based on a solid oxide electrolysis cell further includes a controller;

[0032] The controller is used to obtain and control the water flow rate entering the steam generator, obtain and control the air flow rate entering the SOEC stack; and, after identifying that the gas temperature output by the SOEC stack reaches a preset temperature, start the ammonia synthesizer.

[0033] The beneficial effects of the above improvement scheme are as follows: Only through one controller, the control and optimization of the entire process of ammonia synthesis can be realized, greatly improving the convenience of use, enhancing the user experience, and saving labor costs.

[0034] Furthermore, the controller further includes:

[0035] The data acquisition unit is used to obtain the air flow rate and temperature entering the SOEC stack, the flow rates and temperatures of hydrogen and water vapor respectively in the fuel electrode tail gas output by the SOEC stack, and the gas types and their respective flow rates at the input end of the ammonia synthesizer, and send them to the data processing and control unit;

[0036] The data processing and control unit is used to start the fan and the electric heater, start heat exchangers one, two and the steam generator after the incoming air reaches the set temperature; then, adjust the water flow rate entering the steam generator and the rotation speed of the fan so that the flow rate ratio of hydrogen and water vapor out of the stack reaches the set range for preparing ammonia; and, after the flow rate ratio of hydrogen and water vapor out of the stack reaches the set range for preparing ammonia, monitor the gas temperature output by the SOEC stack. Once the gas temperature output by the SOEC stack reaches the set temperature, start heat exchanger three and the ammonia synthesizer, so that the fuel electrode tail gas output by the SOEC stack enters the ammonia synthesizer at a preset flow rate ratio and temperature to prepare ammonia.

[0037] The beneficial effects of the above improvement scheme are as follows: Control the air, water vapor, and nitrogen for ammonia synthesis respectively, accurately control the temperature and humidity conditions required for synthesizing ammonia, and can improve the synthesis efficiency.

[0038] Furthermore, the data acquisition unit further includes:

[0039] An air flow rate and temperature integrated sensor is arranged at the air inlet of the SOEC stack and is used to obtain the air flow rate and temperature entering the SOEC stack;

[0040] A water flow measurement and control device is provided at the water inlet of the steam generator, which is used to obtain the water flow entering the steam generator and, according to the control instruction of the data processing and control unit, control the water flow entering the steam generator.

[0041] A water vapor flow and temperature integrated sensor is respectively provided at the fuel inlet of the SOEC stack, the fuel electrode tail gas outlet, and the input end of the ammonia synthesizer, which is used to respectively obtain the water vapor flow and temperature entering and discharging from the SOEC stack, and the water vapor flow and temperature entering the ammonia synthesizer.

[0042] A hydrogen flow and temperature integrated sensor is provided at the fuel electrode tail gas outlet of the SOEC stack and the input end of the ammonia synthesizer, which is used to respectively obtain the hydrogen flow and temperature out of the stack and the hydrogen flow and temperature entering the ammonia synthesizer.

[0043] A nitrogen flow and temperature integrated sensor is provided at the input end of the ammonia synthesizer, which is used to respectively obtain the nitrogen flow and temperature entering the ammonia synthesizer.

[0044] The beneficial effects of the above improvement scheme are as follows: The sensors are simple and easy to deploy, and can achieve precise control.

[0045] The invention content part is provided to introduce the selection of concepts in a simplified form, which will be further described in the specific implementation manner below. The invention content part is not intended to identify the important features or essential features of the present disclosure, nor is it intended to limit the scope of the present disclosure. Brief Description of the Drawings

[0046] By describing the exemplary embodiments of the present disclosure in more detail in conjunction with the drawings, the above and other objects, features, and advantages of the present disclosure will become more obvious. Among them, in the exemplary embodiments of the present disclosure, the same reference numerals generally represent the same components.

[0047] Figure 1 Shows the schematic composition diagram of the ammonia synthesis device based on the solid oxide electrolytic cell in Embodiment 1;

[0048] Figure 2 Shows a schematic diagram of the composition of the ammonia synthesis device based on the solid oxide electrolytic cell in Embodiment 2;

[0049] Figure 3 Shows a second schematic diagram of the composition of the ammonia synthesis device based on the solid oxide electrolytic cell in Embodiment 2;

[0050] Figure 4 Shows a third schematic diagram of the composition of the ammonia synthesis device based on the solid oxide electrolytic cell in Embodiment 2;

[0051] Figure 5Figure 4 shows the schematic composition of the ammonia synthesis device based on a solid oxide electrolytic cell in Embodiment 2.

[0052] Reference numerals:

[0053] SOEC - SOEC stack; NH3 synthesis - ammonia synthesizer. Detailed implementation manners

[0054] Embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to make the present disclosure more thorough and complete, and to fully convey the scope of the present disclosure to those skilled in the art.

[0055] As used herein, the term "comprising" and its variants mean open inclusion, i.e., "including but not limited to". Unless otherwise specified, the term "or" means "and / or". The term "based on" means "at least partially based on". The terms "an example embodiment" and "an embodiment" mean "at least one example embodiment". The term "another embodiment" means "at least one additional embodiment". The terms "first", "second", etc. may refer to different or the same objects. Other explicit and implicit definitions may also be included hereinafter.

[0056] Embodiment 1

[0057] An embodiment of the present invention discloses an ammonia synthesis device based on a solid oxide electrolytic cell, as Figure 1 shown, including a SOEC stack, a fan, an electric heater, a steam generator, heat exchangers 1 - 3, and an ammonia synthesizer.

[0058] Among them, the fan, the electric heater, and branch 1 of heat exchanger 1 are connected in sequence to obtain high - temperature air to the air inlet of the SOEC stack; the water vapor obtained by the steam generator enters branch 1 of heat exchanger 2 for the first - stage heat exchange, and then enters branch 2 of heat exchanger 1 to perform the second - stage heat exchange with the above - mentioned high - temperature air to obtain high - temperature water vapor to the fuel inlet of the SOEC stack; the fuel - side tail gas output by the SOEC stack enters branch 2 of heat exchanger 2 for the first - stage heat exchange, and then enters branch 1 of heat exchanger 3 to perform the second - stage heat exchange with the gas in branch 2 of heat exchanger 3 to obtain a mixed gas of high - temperature hydrogen and water vapor and transport it to the ammonia synthesizer.

[0059] Optionally, the gas in branch 1 of heat exchanger 3 can be nitrogen, or a gas used to directly or indirectly heat nitrogen, as in Embodiment 2 Figures 2 to 4 shown.

[0060] During implementation, on the air side of the SOEC stack, after being compressed by a fan, air passes through an electric heater, and its temperature is heated to the set inlet temperature of the stack before entering the stack. The high-temperature tail gas discharged from the stack controls the temperatures of hydrogen, water vapor, and nitrogen entering the ammonia synthesizer through Heat Exchangers I - III. On the fuel gas side of the SOEC stack, liquid water is supplied to the steam generator according to the set demand. After the water vaporizes in the steam generator, it enters Heat Exchangers I and II, exchanges heat with the high-temperature fuel electrode tail gas to increase the water vapor temperature. The fuel electrode tail gas output from the stack, i.e., the water vapor of hydrogen and water vapor, passes through Heat Exchangers II and III, and then exchanges heat with the outside nitrogen or the gas used for heating nitrogen, enabling stable temperature control.

[0061] Compared with the prior art, the ammonia synthesis device based on a solid oxide electrolytic cell provided in this embodiment does not require direct heating of the hydrogen and water vapor mixture, cancels the fuel electrode side electric heater in the prior art, and the two electric heaters before ammonia synthesis. Instead, it heats the air by electricity, then exchanges heat between the high-temperature air and normal-temperature water vapor to heat the water vapor. Then, by using the high-temperature mixed gas of hydrogen and water vapor from the SOEC fuel electrode tail gas and exchanging heat with the gas in Branch II of Heat Exchanger III (i.e., nitrogen or the gas used for directly or indirectly heating nitrogen), the temperature and humidity conditions required for ammonia synthesis are solved from the source. Through effective thermal management, the potential safety hazards brought about by the electric heating of hydrogen and water vapor are avoided. The conditions required for ammonia synthesis can be accurately controlled through the heat exchanger, which can improve the synthesis efficiency. Moreover, only one electric heater is used to provide heat energy for the entire system, reducing components, lowering costs, simplifying the control difficulty of thermal management, and greatly reducing the cost and power consumption of the ammonia synthesis device.

[0062] Example 2

[0063] On the basis of Example 1, an optimization is carried out. The gas in Branch II of Heat Exchanger III is nitrogen at normal temperature and preset pressure. The nitrogen enters Branch II of Heat Exchanger III and exchanges heat with the mixed gas of high-temperature hydrogen and water vapor in its Branch I, and then the high-temperature nitrogen at preset pressure is transported to the ammonia synthesizer, as Figure 2 shown.

[0064] Preferably, the ammonia synthesis device based on a solid oxide electrolytic cell further includes Mixer I. And, the gas in Branch II of Heat Exchanger III is the fuel electrode tail gas output from the SOEC stack; one input end of Mixer I inputs nitrogen at normal temperature and preset pressure, the second input end is connected to the output end of Branch II of Heat Exchanger III, and the output end is connected to the input end of the ammonia synthesizer, so that the high-temperature mixed gas of nitrogen and the fuel electrode tail gas is transported to the ammonia synthesizer, as Figure 3 shown.

[0065] Preferably, the ammonia synthesis device based on a solid oxide electrolysis cell further includes a fourth heat exchanger. And, the gas in the second branch of the third heat exchanger is the fuel electrode tail gas or the air electrode tail gas output by the SOEC stack; nitrogen at normal temperature and a preset pressure is input into the first branch of the fourth heat exchanger, the input end of the second branch is connected to the output end of the second branch of the third heat exchanger, and the output ends of the first and second branches are both connected to the input end of the ammonia synthesizer, so that the obtained high-temperature nitrogen and the mixed gas of high-temperature hydrogen and water vapor are respectively transported to the ammonia synthesizer, as Figure 4 shown.

[0066] Preferably, the ammonia synthesis device based on a solid oxide electrolysis cell further includes a three-way valve and a second mixer. Among them, the three-way valve is arranged at the front end of the fourth heat exchanger, nitrogen at normal temperature and a preset pressure is input into the input end, the first output end is connected to the input end of the first branch of the fourth heat exchanger, and the second output end is connected to the second input end of the second mixer.

[0067] The second mixer is arranged between the fourth heat exchanger and the ammonia synthesizer, its first input end is connected to the output end of the first branch of the fourth heat exchanger, and the output end is connected to the input end of the ammonia synthesizer, so that the obtained high-temperature nitrogen is transported to ammonia synthesis, as Figure 5 shown.

[0068] Preferably, the ammonia synthesis device based on a solid oxide electrolysis cell further includes a nitrogen gas storage cylinder and a booster pump connected in sequence, as Figures 2 to 5 shown. The output end of the booster pump is connected to the input end of the second branch of the third heat exchanger, or the first input end of the first mixer, or the input end of the three-way valve, and is used for transporting the output nitrogen at normal temperature and a preset pressure to the input end of the second branch of the third heat exchanger, or the first input end of the first mixer, or the input end of the three-way valve.

[0069] Preferably, the ammonia synthesis device based on a solid oxide electrolysis cell further includes a water tank and a water pump connected in sequence. Among them, the output end of the water pump is connected to the water inlet of the steam generator.

[0070] Preferably, the ammonia synthesis device based on a solid oxide electrolysis cell further includes an air inlet valve, a water vapor inlet valve and a tail gas throttle valve.

[0071] Among them, the air inlet valve is arranged at the air inlet of the SOEC stack, the water vapor inlet valve is arranged at the water vapor inlet of the SOEC stack, and the tail gas throttle valve is arranged at the tail gas exhaust port of the SOEC stack.

[0072] Preferably, the ammonia synthesis device based on a solid oxide electrolysis cell further includes a controller.

[0073] A controller is used to obtain and control the water flow rate into the steam generator, and obtain and control the air flow rate into the SOEC stack; and, after identifying that the gas temperature output by the SOEC stack reaches a preset temperature, start the ammonia synthesizer.

[0074] Preferably, the controller further includes a data acquisition unit and a data processing and control unit connected in sequence.

[0075] The data acquisition unit is used to obtain the air flow rate and temperature into the SOEC stack, the flow rates and temperatures of hydrogen and water vapor respectively in the fuel electrode tail gas output by the SOEC stack, and the gas type and respective flow rates at the input end of the ammonia synthesizer, and send them to the data processing and control unit.

[0076] The data processing and control unit is used to start the fan and the electric heater, start heat exchangers one and two and the steam generator after the incoming air reaches the set temperature; then, adjust the water flow rate into the steam generator and the rotational speed of the fan so that the flow rate ratio of the hydrogen and water vapor out of the stack reaches the set range for preparing ammonia; and, after the flow rate ratio of the hydrogen and water vapor out of the stack reaches the set range for preparing ammonia, monitor the gas temperature output by the SOEC stack, and once the gas temperature output by the SOEC stack reaches the set temperature, start heat exchanger three and the ammonia synthesizer, so that the fuel electrode tail gas output by the SOEC stack enters the ammonia synthesizer at a preset flow rate ratio and temperature to prepare ammonia.

[0077] Preferably, the data acquisition unit further includes an air flow and temperature integrated sensor, a water flow measurement and control device, a water vapor flow and temperature integrated sensor, a hydrogen flow and temperature integrated sensor, and a nitrogen flow and temperature integrated sensor.

[0078] The air flow and temperature integrated sensor is arranged at the air inlet of the SOEC stack and is used to obtain the air flow rate and temperature into the SOEC stack.

[0079] The water flow measurement and control device is arranged at the water inlet of the steam generator and is used to obtain the water flow rate into the steam generator, and, according to the control instruction of the data processing and control unit, control the water flow rate into the steam generator.

[0080] The water vapor flow and temperature integrated sensor is respectively arranged at the fuel inlet of the SOEC stack, the fuel electrode tail gas outlet, and the input end of the ammonia synthesizer, and is used to respectively obtain the water vapor flow rate and temperature entering and exiting the SOEC stack, and obtain the water vapor flow rate and temperature entering the ammonia synthesizer.

[0081] The hydrogen flow and temperature integrated sensor is arranged at the exhaust gas outlet of the fuel electrode of the SOEC stack and the input end of the ammonia synthesizer, and is used to respectively obtain the hydrogen flow and temperature of the hydrogen gas exiting the stack, and the hydrogen flow and temperature of the hydrogen gas entering the ammonia synthesizer.

[0082] The nitrogen flow and temperature integrated sensor is arranged at the input end of the ammonia synthesizer, and is used to respectively obtain the nitrogen flow and temperature of the nitrogen gas entering the ammonia synthesizer.

[0083] Compared with Embodiment 1, the ammonia synthesis device based on the solid oxide electrolytic cell provided in this embodiment has the following beneficial effects:

[0084] 1. The mixed gas of hydrogen and water vapor in the fuel electrode exhaust gas of the SOEC stack ( Figures 4 to 5 ) can be used to perform heat exchange with the high-temperature air in the air electrode exhaust gas, thus solving the temperature and humidity conditions required for synthesizing ammonia from the source;

[0085] 2. Nitrogen provides the pressure environment required for ammonia synthesis under the action of the booster pump, and at the same time can also control the temperature range required for synthesizing ammonia ( Figures 2 to 5 ), improving the efficiency of ammonia synthesis;

[0086] 3. By using the multi-stage heat exchanger and the booster pump in cooperation to precisely control the conditions required for synthesizing ammonia, the synthesis efficiency can be improved, and multi-stage utilization of energy is achieved;

[0087] 4. Only one electric heating is used to provide heat energy for the entire system, reducing components, lowering costs, and simplifying the control difficulty of heat management.

[0088] The embodiments of the present disclosure have been described above. The above description is exemplary and not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes are obvious to those of ordinary skill in the art in the technical field without departing from the scope and spirit of the described embodiments. The selection of the terms used herein is intended to best explain the principles of the embodiments, practical applications, or improvements to the prior art, or to enable other ordinary skill in the art in the technical field to understand the disclosed embodiments.

Claims

1. An ammonia synthesis device based on a solid oxide electrolyzer, characterized in that, It includes an SOEC stack, a fan, an electric heater, a steam generator, heat exchangers I - III, and an ammonia synthesizer; among them, The fan, the electric heater, and branch I of heat exchanger I are connected in sequence to obtain high-temperature air to the air inlet of the SOEC stack; The water vapor obtained by the steam generator enters branch I of heat exchanger II for the first-stage heat exchange, and then enters branch II of heat exchanger I to perform the second-stage heat exchange with the above-mentioned high-temperature air to obtain high-temperature water vapor to the fuel inlet of the SOEC stack; The fuel electrode tail gas output by the SOEC stack enters branch II of heat exchanger II for the first-stage heat exchange, and then enters branch I of heat exchanger III to perform the second-stage heat exchange with the gas in branch II of heat exchanger III to obtain a mixed gas of high-temperature hydrogen and water vapor and is transported to the ammonia synthesizer; The gas in branch II of heat exchanger III is nitrogen at normal temperature and a preset pressure; The nitrogen enters branch II of heat exchanger III and exchanges heat with the mixed gas of high-temperature hydrogen and water vapor in its branch I to obtain high-temperature nitrogen at a preset pressure and is transported to the ammonia synthesizer.

2. The ammonia synthesis device based on a solid oxide electrolyzer according to claim 1, wherein It also includes mixer I; and, The gas in branch II of heat exchanger III is the fuel electrode tail gas output by the SOEC stack; Input terminal I of mixer I inputs nitrogen at normal temperature and a preset pressure, input terminal II is connected to the output terminal of branch II of heat exchanger III, and the output terminal is connected to the input terminal of the ammonia synthesizer, so as to obtain a high-temperature mixed gas of nitrogen and fuel electrode tail gas and transport it to the ammonia synthesizer.

3. The ammonia synthesis device based on a solid oxide electrolyzer according to claim 1, wherein It also includes heat exchanger IV; and, The gas in branch II of heat exchanger III is the fuel electrode tail gas or the air electrode tail gas output by the SOEC stack; Nitrogen at normal temperature and a preset pressure is input into branch I of heat exchanger IV, the input terminal of branch II is connected to the output terminal of branch II of heat exchanger III, and the output terminals of branch I and branch II are both connected to the input terminal of the ammonia synthesizer, so that the obtained high-temperature nitrogen and the mixed gas of high-temperature hydrogen and water vapor are respectively transported to the ammonia synthesizer.

4. The ammonia synthesis device based on a solid oxide electrolyzer according to claim 3, wherein, It also includes a three-way valve and mixer II; among them, The three-way valve is arranged at the front end of heat exchanger IV, the input terminal inputs nitrogen at normal temperature and a preset pressure, output terminal I is connected to the input terminal of branch I of heat exchanger IV, and output terminal II is connected to the input terminal of mixer II; Mixer II is arranged between heat exchanger IV and the ammonia synthesizer, its input terminal I is connected to the output terminal of branch I of heat exchanger IV, and the output terminal is connected to the input terminal of the ammonia synthesizer, so that the obtained high-temperature nitrogen is transported to the ammonia synthesizer.

5. The ammonia synthesis device based on a solid oxide electrolyzer according to any one of claims 1-4, characterized in that, It also includes a nitrogen gas cylinder and a booster pump connected in sequence; The output terminal of the booster pump is connected to the input terminal of branch II of heat exchanger III, or the input terminal I of mixer I, or the input terminal of the three-way valve, and is used to transport the output nitrogen at normal temperature and a preset pressure to the input terminal of branch II of heat exchanger III, or the input terminal I of mixer I, or the input terminal of the three-way valve.

6. The ammonia synthesis device based on a solid oxide electrolyzer according to any one of claims 1-4, characterized in that, It also includes a water tank and a water pump connected in sequence; among them, The output terminal of the water pump is connected to the water inlet of the steam generator.

7. The ammonia synthesis device based on a solid oxide electrolyzer according to any one of claims 1-4, characterized in that, It also includes a controller; A controller is used to acquire and control the water flow rate into the steam generator, and acquire and control the air flow rate into the SOEC stack; and, after identifying that the gas temperature output by the SOEC stack reaches a preset temperature, start the ammonia synthesizer.

8. The ammonia synthesis device based on a solid oxide electrolyzer according to claim 7, wherein, The controller further includes: A data acquisition unit is used to acquire the air flow rate and temperature into the SOEC stack, the flow rates and temperatures of hydrogen and water vapor respectively in the fuel electrode tail gas output by the SOEC stack, and the gas type and respective flow rates at the input end of the ammonia synthesizer, and send them to the data processing and control unit; A data processing and control unit is used to start the fan and the electric heater, start heat exchangers one, two and the steam generator after the incoming air reaches the set temperature; then, adjust the water flow rate into the steam generator and the rotation speed of the fan so that the flow rate ratio of the hydrogen and water vapor out of the stack reaches the set range for ammonia production; and, after the flow rate ratio of the hydrogen and water vapor out of the stack reaches the set range for ammonia production, monitor the gas temperature output by the SOEC stack. Once the gas temperature output by the SOEC stack reaches the set temperature, start heat exchanger three and the ammonia synthesizer, so that the fuel electrode tail gas output by the SOEC stack enters the ammonia synthesizer at a preset flow rate ratio and temperature to produce ammonia.

9. The ammonia synthesis device based on a solid oxide electrolyzer according to claim 8, characterized in that, The data acquisition unit further includes: An air flow and temperature integrated sensor is arranged at the air inlet of the SOEC stack and is used to acquire the air flow rate and temperature into the SOEC stack; A water flow measurement and control device is arranged at the water inlet of the steam generator and is used to acquire the water flow rate into the steam generator, and, according to the control instruction of the data processing and control unit, control the water flow rate into the steam generator; A water vapor flow and temperature integrated sensor is respectively arranged at the fuel inlet, the fuel electrode tail gas outlet of the SOEC stack, and the input end of the ammonia synthesizer, and is used to respectively acquire the water vapor flow rate and temperature entering and discharging from the SOEC stack, and acquire the water vapor flow rate and temperature entering the ammonia synthesizer; A hydrogen flow and temperature integrated sensor is arranged at the fuel electrode tail gas outlet of the SOEC stack and the input end of the ammonia synthesizer, and is used to respectively acquire the hydrogen flow rate and temperature out of the stack and the hydrogen flow rate and temperature entering the ammonia synthesizer; A nitrogen flow and temperature integrated sensor is arranged at the input end of the ammonia synthesizer and is used to respectively acquire the nitrogen flow rate and temperature entering the ammonia synthesizer.

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