Electro-ammonia-heat multi-energy conversion system adapting to offshore wind power fluctuation and control method thereof

Abstract

The invention discloses an electricity ammonia heat multi-energy conversion system adapting to offshore wind power fluctuation and a control method of the electricity ammonia heat multi-energy conversion system. The electric ammonia heat multi-energy conversion system comprises a green hydrogen preparation system, a green ammonia synthesis system, a green ammonia power generation system and a green ammonia heat supply system, the electric ammonia heat multi-energy conversion system is controlled by adopting the wind power absorption module and the power generation heat supply module. According to the invention, offshore wind power is utilized to prepare green hydrogen and synthesize green ammonia, offshore new energy consumption and medium-and-long-term storage of electric power are realized, low-cost long-distance flexible transportation of energy is realized through a liquid ammonia mode, the problem of storage and transportation of hydrogen energy is solved, and the construction investment of offshore transmission channels is reduced; energy supply diversification can be achieved through green ammonia power generation and green ammonia heat supply; meanwhile, through the unique control method, the method can effectively adapt to the strong volatility of offshore wind power, and economical and efficient preparation and diversified utilization of the green ammonia are achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of multi-energy conversion systems, and in particular to an electric-ammonia-heat multi-energy conversion system and a control method thereof that can adapt to offshore wind power fluctuations. Background Art

[0002] Offshore wind power has the characteristics of rich resources, high power generation utilization hours, no land occupation and suitability for large-scale development. However, the construction of offshore power transmission channels requires huge investment, and the large-scale random and volatile access to new energy power also poses challenges to the stable and safe operation of the power grid. New new energy consumption and storage technologies are urgently needed to solve such problems and promote the transformation of terminal energy consumption from mainly electric energy substitution to diversified clean substitution such as electricity, hydrogen, and ammonia.

[0003] The ammonia storage and transportation system is mature, with low storage and transportation costs and high safety. It can be produced through new energy power drive, thus meeting seasonal, long-distance, and long-term zero-carbon energy storage. Electric ammonia heat multi-energy conversion technology is a new energy coupling method using green ammonia as a carrier. It can flexibly adapt to new energy fluctuations and medium- and long-term electricity storage. It can also use liquid ammonia to achieve low-cost long-distance energy transportation, reduce investment in transmission channel construction, and achieve energy supply diversification and improve energy supply stability through green ammonia power generation and heating. At present, in the process of realizing offshore energy development and utilization, there are problems such as high pressure on offshore wind power consumption, high difficulty in medium- and long-term electricity storage, and the stability of single power supply needs to be improved. Summary of the invention

[0004] In view of the problems existing in the above-mentioned prior art, the present invention provides an electric-ammonia-heat multi-energy conversion system and a control method thereof that are adaptable to offshore wind power fluctuations, so as to achieve the purposes of new energy consumption, low-cost transportation of liquid ammonia, green and safe long-term energy storage, and diversified and stabilized energy supply.

[0005] To this end, the present invention adopts the following technical solution.

[0006] In a first aspect, the present invention provides an electric-ammonia-heat multi-energy conversion system that adapts to offshore wind power fluctuations, which includes a green hydrogen production system, a green ammonia synthesis system, a green ammonia power generation system, and a green ammonia heating system;

[0007] The green hydrogen production system includes an offshore wind power generation system, a seawater desalination system, a fresh water tank, an alkaline electrolysis hydrogen production system, a PEM electrolysis hydrogen production system and a hydrogen buffer tank; the seawater desalination system is used to process seawater into fresh water and store it in the fresh water tank, the fresh water from the fresh water tank is respectively sent to the alkaline electrolysis hydrogen production system and the PEM electrolysis hydrogen production system, and hydrogen is produced by using the electricity generated by the offshore wind power generation system, and the obtained hydrogen is stored in the hydrogen buffer tank;

[0008] The green ammonia synthesis system comprises an air separation unit, a nitrogen buffer tank, a nitrogen compressor, a hydrogen compressor, a hydrogen-nitrogen mixing tank, an ammonia synthesis tower, an ammonia cooling tower, an ammonia separator, a centrifugal pump, a liquid ammonia storage tank and a circulating compressor; the air separation unit is used to separate nitrogen from the air and send it to the nitrogen buffer tank, the nitrogen in the nitrogen buffer tank is compressed by the nitrogen compressor and then sent to the hydrogen-nitrogen mixing tank, the hydrogen in the hydrogen buffer tank is compressed by the hydrogen compressor and then sent to the hydrogen-nitrogen mixing tank, the mixed gas in the hydrogen-nitrogen mixing tank is used to be sent to the ammonia synthesis tower for green ammonia synthesis, the obtained mixed gas of ammonia, nitrogen and hydrogen enters the ammonia cooling tower for cooling, the cooled mixed substance enters the ammonia separator for separation, the mixed gas located at the upper part of the ammonia separator is sent back to the hydrogen-nitrogen mixing tank through the circulating compressor and is used as the raw gas for synthesizing ammonia again; the liquid ammonia located at the lower part of the ammonia separator is sent to the liquid ammonia storage tank through the centrifugal pump;

[0009] The green ammonia power generation system comprises a liquid ammonia delivery pump, a liquid ammonia delivery valve, a liquid ammonia vaporizer, an ammonia pressure reducing valve, a heat exchanger, an ammonia cracker, a cooler, a dryer, a hydrogen-nitrogen buffer tank, a hydrogen-nitrogen delivery valve, a hydrogen fuel cell and a DC / AC inverter; the liquid ammonia delivery pump is used to deliver the liquid ammonia in the liquid ammonia storage tank to the liquid ammonia vaporizer through the liquid ammonia delivery valve for vaporization, the vaporized ammonia gas enters the heat exchanger after passing through the ammonia pressure reducing valve, and after heat exchange with the high-temperature hydrogen-nitrogen mixed gas from the ammonia cracker, enters the ammonia cracker and is decomposed into hydrogen and nitrogen under the action of a catalyst, the hydrogen-nitrogen mixed gas is cooled by the heat exchanger and the cooler, and then enters the dryer to remove moisture from the hydrogen-nitrogen mixed gas, the dried hydrogen-nitrogen mixed gas enters the hydrogen-nitrogen buffer tank for storage, the hydrogen-nitrogen mixed gas in the hydrogen-nitrogen buffer tank is delivered to the hydrogen fuel cell through the hydrogen-nitrogen delivery valve for power generation, and the generated power is connected to the grid through the DC / AC inverter;

[0010] The green ammonia heating system comprises a constant temperature water tank, a cooler cooling water delivery pump, a cooler cooling water delivery valve, a fuel cell coolant tank, a fuel cell coolant delivery pump, a fuel cell coolant delivery valve, a fuel cell waste heat exchanger, a waste heat exchanger cooling water delivery pump and a waste heat exchanger cooling water delivery valve; the cold water at the bottom layer of the constant temperature water tank passes through the cooler cooling water delivery pump and the cooler cooling water delivery valve and enters the cooler for heat exchange, and the hot water after heat exchange enters the upper layer of the constant temperature water tank; at the same time, the coolant in the fuel cell coolant tank passes through the fuel cell coolant delivery pump and the fuel cell coolant delivery valve and enters the hydrogen fuel cell for cooling, and the coolant after heat exchange exchanges heat with the cooling water from the waste heat exchanger cooling water delivery pump and the waste heat exchanger cooling water delivery valve in the fuel cell waste heat exchanger, and the hot water after heat exchange is used to enter the upper layer of the constant temperature water tank.

[0011] Furthermore, the mixed gas in the hydrogen-nitrogen mixing tank passes through the outlet valve of the hydrogen-nitrogen mixing tank and is compressed by a multi-stage compressor and then sent to the ammonia synthesis tower for green ammonia synthesis.

[0012] Furthermore, the liquid ammonia vaporizer of the green ammonia power generation system is a plate heat exchanger, which vaporizes the liquid ammonia in a water bath using hot water heated by an electric heater to keep the ammonia at 44-46°C and 1.4-1.6MPa, and the electric heater power and hot water temperature can be adjusted as needed to change the pressure and temperature of the ammonia.

[0013] Furthermore, the ammonia cracker of the green ammonia power generation system adopts nickel-chromium alloy with excellent performance at high temperature as an electric heating element, and accurately controls the cracking temperature through an electrical temperature control device. At the same time, a low-temperature Ni-Ru-based ammonia decomposition hydrogen production catalyst is used to achieve more than 99.5% of ammonia decomposition into hydrogen-nitrogen mixed gas at normal pressure and 475-485°C.

[0014] In a second aspect, the present invention provides a control method for the above-mentioned electric-ammonia-heat multi-energy conversion system, which adopts a wind power consumption module and a power generation and heating module for control;

[0015] The wind power consumption module uses an alkaline electrolysis hydrogen production system and a PEM electrolysis hydrogen production system in combination, and adjusts the power of the air separation unit, the outlet valve of the hydrogen-nitrogen mixing tank and the power of the ammonia synthesis tower to effectively adapt to offshore wind power fluctuations;

[0016] The power generation and heating module realizes power generation change by adjusting the power of the liquid ammonia delivery pump, the liquid ammonia delivery valve, the ammonia cracker power and the hydrogen-nitrogen delivery valve, and realizes precise temperature control by adjusting the cold water inlet valve of the constant temperature water tank, the hot water outlet valve of the constant temperature water tank, the cooler cooling water delivery valve and the waste heat exchanger cooling water delivery valve.

[0017] Furthermore, the load distribution equation of the electrolysis hydrogen production system of the wind power consumption module includes the total power equation of the electrolysis hydrogen production system, the load distribution equation of the PEM electrolysis hydrogen production system and the load distribution equation of the alkaline electrolysis hydrogen production system; wherein the total power equation of the electrolysis hydrogen production system is:

[0018]

[0019] In the formula, P0 is the total power of the electrolytic hydrogen production system, n is the total number of PEM electrolytic hydrogen production devices, α 1i is the workload of the ith PEM electrolysis hydrogen production device, P 1i is the rated power of the ith PEM electrolysis hydrogen production device, m is the total number of alkaline electrolysis hydrogen production devices, α 2j is the workload of the jth alkaline electrolysis hydrogen production unit, P 2j is the rated power of the jth alkaline electrolysis hydrogen production device;

[0020] The load distribution equation of the PEM electrolysis hydrogen production system is:

[0021]

[0022] Where P1 is the actual total operating power of the PEM electrolysis hydrogen production system, P 1t is the power required by the PEM electrolysis hydrogen production system, P 1min is the minimum single rated power of the PEM electrolysis hydrogen production device, α 11 is the workload of the PEM electrolysis hydrogen production device with the minimum rated power, k is the number of PEM electrolysis hydrogen production devices operating at rated power, α 12 is the fixed value of the PEM electrolysis hydrogen production device between 0-100% of the working load, α 13 It is the set value of the PEM electrolysis hydrogen production device between 100% and 160% of the working load;

[0023] The load distribution equation of the alkaline electrolysis hydrogen production system is:

[0024]

[0025] Where P2 is the actual total operating power of the alkaline electrolysis hydrogen production system, P 2t is the power required by the alkaline electrolysis hydrogen production system, P 2min is the minimum single rated power of the alkaline electrolysis hydrogen production device, α 21 is the workload of the alkaline electrolysis hydrogen production unit at the minimum rated power, h is the number of alkaline electrolysis hydrogen production units operating at rated power, α 22 It is the set value of the alkaline electrolysis hydrogen production device between 10% and 100% of the working load.

[0026] Furthermore, the wind power consumption module uses the PEM electrolysis hydrogen production system when the offshore wind power output is small and the green hydrogen production system needs to operate at a low load of less than 10%. The load is distributed according to the load distribution equation of the electrolysis hydrogen production system, and the power of the air separation unit, the outlet valve of the hydrogen-ammonia mixing tank and the power of the ammonia synthesis tower are reduced, thereby reducing the amount of hydrogen and ammonia produced. When the offshore wind power is relatively stable and the green hydrogen production system is operating at a load of 10-100%, the alkaline electrolysis hydrogen production system is used first and the PEM electrolysis hydrogen production system is used as a supplement. According to the load distribution equation of the electrolysis hydrogen production system, the power of the air separation unit, the outlet valve of the hydrogen-ammonia mixing tank and the power of the ammonia synthesis tower are reduced, thereby reducing the amount of hydrogen and ammonia produced. The alkaline electrolysis hydrogen production system adopts pulse current electrolysis mode to meet the requirements of high-efficiency and low-load operation, and adopts DC current electrolysis mode to meet the requirements of high-efficiency and high-load operation, and adjusts the power of the air separation unit, the outlet valve of the hydrogen-ammonia mixing tank and the power of the ammonia synthesis tower accordingly; when the offshore wind power output is large and the green hydrogen production system needs to operate under an overload condition greater than 100%, the PEM electrolysis hydrogen production system is used to distribute the load according to the load distribution equation of the hydrogen electrolysis system, and increase the power of the air separation unit, the outlet valve of the hydrogen-ammonia mixing tank and the power of the ammonia synthesis tower, thereby increasing the amount of hydrogen and ammonia produced.

[0027] Furthermore, the wind power consumption module monitors the operating status and performance data of each electrolytic hydrogen production device in real time through the control system, and dynamically adjusts the hydrogen production power of each electrolytic hydrogen production device according to the principle of allocation according to the operating power ratio; at the same time, the PEM electrolytic hydrogen production system is used as the second-level load response, and the alkaline electrolytic hydrogen production system is used as the minute-level load response.

[0028] Furthermore, the energy balance equation of the power generation and heating module includes two parts: the cooler and the fuel cell waste heat exchanger; wherein the energy balance equation of the cooler is:

[0029]

[0030] In the formula, q0 is the mass flow rate of the mixed gas at the inlet of the cooler, η0 is the heat exchange efficiency between the hydrogen-nitrogen mixed gas and the cooling water of the cooler, c0 is the comprehensive specific heat of the mixed gas at the inlet of the cooler, T0 is the temperature of the mixed gas at the inlet of the cooler, ρ0 is the comprehensive density of the mixed gas at the inlet of the cooler, c1 is the comprehensive specific heat of the mixed gas at the outlet of the cooler, T1 is the temperature of the mixed gas at the outlet of the cooler, ρ1 is the comprehensive density of the mixed gas at the outlet of the cooler, q1 is the mass flow rate of the cooling water at the inlet of the cooler, and c 11 is the specific heat of the cooling water at the inlet of the cooler, T 11 is the inlet cooling water temperature of the cooler, ρ 11 is the cooling water density at the inlet of the cooler, c 12 is the specific heat of cooling water at the cooler outlet, T 12 is the outlet cooling water temperature of the cooler, ρ 12 is the cooling water density at the outlet of the cooler;

[0031] The energy balance equation of the fuel cell waste heat exchanger is:

[0032]

[0033] Where q2 is the mass flow rate of the inlet coolant of the fuel cell waste heat exchanger, η2 is the heat exchange efficiency between the coolant and the cooling water of the waste heat exchanger, and c 21 is the specific heat of the inlet coolant of the waste heat exchanger, T 21 is the inlet coolant temperature of the waste heat exchanger, ρ 21 is the inlet coolant density of the waste heat exchanger, c 22 is the outlet coolant specific heat of the waste heat exchanger, T 22 is the outlet coolant temperature of the waste heat exchanger, ρ 22 is the outlet coolant density of the waste heat exchanger, q3 is the inlet cooling water mass flow rate of the fuel cell waste heat exchanger, c 32 is the specific heat of the cooling water at the outlet of the waste heat exchanger, T 32 is the outlet cooling water temperature of the waste heat exchanger, ρ 32is the cooling water density at the outlet of the waste heat exchanger, c 31 is the specific heat of the cooling water at the inlet of the waste heat exchanger, T 31 is the inlet cooling water temperature of the waste heat exchanger, ρ 31 is the inlet cooling water density of the waste heat exchanger.

[0034] Furthermore, when the power generation and heating module needs to increase the power generation and maintain stable heat supply, it promotes the decomposition of more liquid ammonia by increasing the power of the liquid ammonia delivery pump, the opening of the liquid ammonia delivery valve and the power of the ammonia cracker, and increases the flow rate and pressure of hydrogen delivered to the hydrogen fuel cell by increasing the hydrogen nitrogen delivery valve, thereby increasing the power generation. At this time, the waste heat of the cooler and the hydrogen fuel cell of the green ammonia power generation system will increase. Combined with the energy balance equation of the power generation and heating module, the cooling of the cooler is accelerated by increasing the power of the cooler delivery pump and the opening of the cooling water delivery valve, and the cooling of the hydrogen fuel cell is accelerated by increasing the power of the coolant delivery pump, the opening of the coolant valve, and the power of the waste heat exchanger cooling water delivery pump and the opening of the cooling water delivery valve, and the opening of the cold water inlet valve and the hot water outlet valve are increased, thereby achieving stable heat supply;

[0035] When it is necessary to reduce the power generation and maintain a stable heat supply, the liquid ammonia decomposition is reduced by reducing the power of the liquid ammonia delivery pump, the opening of the liquid ammonia delivery valve and the power of the ammonia cracker. The hydrogen flow and pressure delivered to the hydrogen fuel cell are reduced by reducing the hydrogen nitrogen delivery valve, thereby reducing the power generation. At this time, the waste heat of the cooler and hydrogen fuel cell of the green ammonia power generation system will be reduced. Combined with the energy balance equation of the power generation and heating module, stable heat supply can be achieved by reducing the opening of the cold water inlet valve.

[0036] The beneficial effects of the present invention are as follows:

[0037] 1. The present invention utilizes offshore wind power to produce green ammonia, which can effectively smooth out fluctuations in new energy output, help absorb new energy, promote medium- and long-term storage of electricity, and provide a solution for low-cost, long-distance and flexible transportation of energy.

[0038] 2. The present invention effectively adapts to the fluctuation of offshore wind power and realizes the economical and efficient production of green ammonia through the wind power consumption module, realizes flexible power generation and stable heat supply through the power generation and heating module, improves the development of offshore wind power and the level of energy supply diversification, and reduces the investment cost of offshore transmission channel construction.

[0039] 3. The wind power consumption and power generation and heating control logic of the present invention is clear. The wind power consumption module adopts the method of cooperating with the alkaline electrolysis hydrogen production system and the PEM electrolysis hydrogen production system, and adjusts the power of the air separation unit, the hydrogen-nitrogen mixing tank outlet valve and the ammonia synthesis tower power to effectively adapt to the fluctuation of offshore wind power; the power generation and heating module realizes the change of power generation power by adjusting the liquid ammonia delivery pump power, liquid ammonia delivery valve, ammonia cracker power and hydrogen-nitrogen delivery valve, and realizes stable heating by adjusting the cold water inlet valve, hot water outlet valve, cooler cooling water delivery valve and waste heat exchanger cooling water delivery valve, thereby realizing flexible conversion of electricity, ammonia and heat.

[0040] 4. The electric-ammonia-heat multi-energy conversion system of the present invention has a unique design and a novel and effective control method. Each part can be used according to the design concept and can also be appropriately adjusted to ensure offshore wind power consumption, green and safe long-term energy storage, and diversified and stable energy supply. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 It is a structural schematic diagram of an electric-ammonia-heat multi-energy conversion system of the present invention that adapts to offshore wind power fluctuations;

[0042] In the figure, 1-offshore wind power generation system; 2-seawater desalination system; 3-fresh water tank; 4-alkaline electrolysis hydrogen production system; 5-PEM electrolysis hydrogen production system; 6-hydrogen buffer tank; 7-hydrogen compressor; 8-air separation unit; 9-nitrogen buffer tank; 10-nitrogen compressor; 11-hydrogen and nitrogen mixing tank; 12-hydrogen and nitrogen mixing tank outlet valve; 13-multi-stage compressor; 14-ammonia synthesis tower; 15-ammonia cooling tower; 16-ammonia separator; 17-centrifugal pump; 18-liquid ammonia storage tank; 19-circulating compressor; 20-liquid ammonia delivery valve; 21-liquid ammonia delivery pump; 22-liquid ammonia vaporizer; 2 3- ammonia pressure reducing valve; 24- heat exchanger; 25- ammonia cracker; 26- cooler; 27- dryer; 28- hydrogen and nitrogen buffer tank; 29- hydrogen and nitrogen delivery valve; 30- hydrogen fuel cell; 31- constant temperature water tank; 32- cooler cooling water delivery valve; 33- cooler cooling water delivery pump; 34- waste heat exchanger cooling water delivery valve; 35- waste heat exchanger cooling water delivery pump; 36- fuel cell waste heat exchanger; 37- fuel cell coolant tank; 38- fuel cell coolant delivery valve; 39- fuel cell coolant delivery pump; 40- cold water inlet valve; 41- hot water outlet valve.

[0043] Figure 2 It is a logic diagram of the wind power consumption module of the present invention;

[0044] Figure 3 It is a logic diagram of the power generation and heating module of the present invention. DETAILED DESCRIPTION

[0045] In order to facilitate the understanding of the present invention, the present invention is described in more detail below in conjunction with the accompanying drawings and specific embodiments of the specification. Preferred embodiments of the present invention are provided in the accompanying drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described in this specification. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0046] It should be noted that, unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0047] Example 1

[0048] This embodiment provides an electric-ammonia-heat multi-energy conversion system that adapts to offshore wind power fluctuations. Figure 1 As shown, it includes a green hydrogen production system, a green ammonia synthesis system, a green ammonia power generation system and a green ammonia heating system.

[0049] The green hydrogen production system includes an offshore wind power generation system 1, a seawater desalination system 2, a fresh water tank 3, an alkaline electrolysis hydrogen production system 4, a PEM electrolysis hydrogen production system 5 and a hydrogen buffer tank 6; the seawater desalination system 2 is used to process seawater into fresh water and store it in the fresh water tank 3, the fresh water from the fresh water tank 3 is respectively sent to the alkaline electrolysis hydrogen production system 4 and the PEM electrolysis hydrogen production system 5, and hydrogen is produced using the electricity generated by the offshore wind power generation system 1, and the obtained hydrogen is stored in the hydrogen buffer tank 6 for subsequent use.

[0050] The green ammonia synthesis system comprises an air separation device 8, a nitrogen buffer tank 9, a nitrogen compressor 10, a hydrogen compressor 7, a hydrogen-nitrogen mixing tank 11, a hydrogen-nitrogen mixing tank outlet valve 12, a multi-stage compressor 13, an ammonia synthesis tower 14, an ammonia cooling tower 15, an ammonia separator 16, a centrifugal pump 17, a liquid ammonia storage tank 18 and a circulating compressor 19; the air separation device 8 is used to separate nitrogen from the air and send it to the nitrogen buffer tank 9, the nitrogen in the nitrogen buffer tank 9 is compressed by the nitrogen compressor 10 and then sent to the hydrogen-nitrogen mixing tank 11, and the hydrogen in the hydrogen buffer tank 6 is compressed by the hydrogen compressor 7 and then also sent to the circulating compressor 19; The mixed gas in the hydrogen-nitrogen mixing tank 11 passes through the hydrogen-nitrogen mixing tank outlet valve 12 and is compressed by the multi-stage compressor 13 and then sent to the ammonia synthesis tower 14 for green ammonia synthesis. The obtained mixed gas of ammonia, nitrogen and hydrogen enters the ammonia cooling tower 15 for cooling. The cooled mixed substance enters the ammonia separator 16 for separation. The mixed gas located at the upper part of the ammonia separator 16 is sent back to the hydrogen-nitrogen mixing tank 11 through the circulation compressor and is used as the raw gas for synthesizing ammonia again. The liquid ammonia located at the lower part of the ammonia separator 16 is sent to the liquid ammonia storage tank 18 through the centrifugal pump 17 for subsequent transportation or use.

[0051] The green ammonia power generation system includes a liquid ammonia delivery pump 21, a liquid ammonia delivery valve 20, a liquid ammonia vaporizer 22, an ammonia pressure reducing valve 23, a heat exchanger 24, an ammonia cracker 25, a cooler 26, a dryer 27, a hydrogen-nitrogen buffer tank 28, a hydrogen-nitrogen delivery valve 29, a hydrogen fuel cell 30 and a DC / AC inverter; the liquid ammonia delivery pump 21 is used to deliver the liquid ammonia in the liquid ammonia storage tank 18 to the liquid ammonia vaporizer 22 through the liquid ammonia delivery valve 20 for vaporization, and the vaporized ammonia gas enters the heat exchanger 24 after passing through the ammonia pressure reducing valve 23. After heat exchange with the high-temperature hydrogen-nitrogen mixed gas from the ammonia cracker 25, it enters the ammonia cracker 25 and is decomposed into hydrogen and nitrogen under the action of the catalyst. The hydrogen-nitrogen mixed gas is cooled by the heat exchanger 24 and the cooler 26, and then enters the dryer 27 to remove moisture from the hydrogen-nitrogen mixed gas. The dried hydrogen-nitrogen mixed gas enters the hydrogen-nitrogen buffer tank 28 for storage. The hydrogen-nitrogen mixed gas in the hydrogen-nitrogen buffer tank 28 is sent to the hydrogen fuel cell 30 through the hydrogen-nitrogen delivery valve 29 to generate electricity, and the generated electricity is connected to the grid through the DC / AC inverter.

[0052] The green ammonia heating system includes a constant temperature water tank 31, a cooler cooling water delivery pump 33, a cooler cooling water delivery valve 32, a fuel cell coolant tank 37, a fuel cell coolant delivery pump 39, a fuel cell coolant delivery valve 38, a fuel cell waste heat exchanger 36, a waste heat exchanger cooling water delivery pump 35 and a waste heat exchanger cooling water delivery valve 34; the cold water at the bottom of the constant temperature water tank 31 passes through the cooler cooling water delivery pump 33 and the cooler cooling water delivery valve 32 and then enters the cooler 26 for heat exchange. The heated hot water enters the upper layer of the constant temperature water tank 31 for subsequent heating; at the same time, the coolant in the fuel cell coolant tank 37 passes through the fuel cell coolant delivery pump 39 and the fuel cell coolant delivery valve 38 and enters the hydrogen fuel cell 30 for cooling. The coolant after heat exchange is exchanged with the cooling water from the waste heat exchanger cooling water delivery pump 35 and the waste heat exchanger cooling water delivery valve 34 in the fuel cell waste heat exchanger 36, and the hot water after heat exchange is used to enter the upper layer of the constant temperature water tank 31 for subsequent heating.

[0053] The liquid ammonia vaporizer of the green ammonia power generation system is a plate heat exchanger. The liquid ammonia is vaporized in a water bath by hot water heated by an electric heater, so that the ammonia is maintained at 44-46°C (most preferably 45°C) and 1.4-1.6MPa (most preferably 1.5MPa). The power of the electric heater and the temperature of the hot water can be adjusted as needed to change the pressure and temperature of the ammonia.

[0054] The ammonia cracker of the green ammonia power generation system adopts nickel-chromium alloy with excellent performance at high temperature as an electric heating element, and accurately controls the cracking temperature through an electrical temperature control device. At the same time, a low-temperature Ni-Ru-based ammonia decomposition hydrogen production catalyst is used to achieve more than 99.5% of ammonia decomposition into hydrogen-nitrogen mixed gas at normal pressure and 475-485°C.

[0055] The green ammonia heating system is equipped with a temperature monitoring device to observe the water level and temperature changes in the constant temperature water tank in real time, and accurately control the hot water temperature by adjusting various valves.

[0056] Example 2

[0057] This embodiment provides a control method for the electric-ammonia-heat multi-energy conversion system described in Embodiment 1, which adopts a wind power consumption module and a power generation and heating module for control.

[0058] The wind power consumption module uses an alkaline electrolysis hydrogen production system and a PEM electrolysis hydrogen production system in combination, and adjusts the power of the air separation unit, the outlet valve of the hydrogen-nitrogen mixing tank and the power of the ammonia synthesis tower to effectively adapt to offshore wind power fluctuations;

[0059] The power generation and heating module realizes power generation change by adjusting the power of the liquid ammonia delivery pump, the liquid ammonia delivery valve, the ammonia cracker power and the hydrogen-nitrogen delivery valve, and realizes precise temperature control by adjusting the cold water inlet valve of the constant temperature water tank, the hot water outlet valve of the constant temperature water tank, the cooler cooling water delivery valve and the waste heat exchanger cooling water delivery valve.

[0060] Specifically, the load distribution equation of the electrolysis hydrogen production system of the wind power consumption module includes the total power equation of the electrolysis hydrogen production system, the load distribution equation of the PEM electrolysis hydrogen production system and the load distribution equation of the alkaline electrolysis hydrogen production system; wherein the total power equation of the electrolysis hydrogen production system is:

[0061]

[0062] In the formula, P0 is the total power of the electrolytic hydrogen production system, n is the total number of PEM electrolytic hydrogen production devices, α 1i is the workload of the ith PEM electrolysis hydrogen production device, P 1i is the rated power of the ith PEM electrolysis hydrogen production device, m is the total number of alkaline electrolysis hydrogen production devices, α 2j is the workload of the jth alkaline electrolysis hydrogen production unit, P 2j is the rated power of the jth alkaline electrolysis hydrogen production device.

[0063] The load distribution equation of the PEM electrolysis hydrogen production system is:

[0064]

[0065] Where P1 is the actual total operating power of the PEM electrolysis hydrogen production system, P 1t is the power required by the PEM electrolysis hydrogen production system, P 1min is the minimum single rated power of the PEM electrolysis hydrogen production device, α 11 is the workload of the PEM electrolysis hydrogen production device with the minimum rated power, k is the number of PEM electrolysis hydrogen production devices operating at rated power, α12 is the fixed value of the PEM electrolysis hydrogen production device between 0-100% of the working load, α 13 It is the set value of the PEM electrolysis hydrogen production device between 100% and 160% of the working load.

[0066] The load distribution equation of the alkaline electrolysis hydrogen production system is:

[0067]

[0068] Where P2 is the actual total operating power of the alkaline electrolysis hydrogen production system, P 2t is the power required by the alkaline electrolysis hydrogen production system, P 2min is the minimum single rated power of the alkaline electrolysis hydrogen production device, α 21 is the workload of the alkaline electrolysis hydrogen production unit at the minimum rated power, h is the number of alkaline electrolysis hydrogen production units operating at rated power, α 22 It is the set value of the alkaline electrolysis hydrogen production device between 10% and 100% of the working load.

[0069] like Figure 2 As shown, the wind power consumption module uses the PEM electrolysis hydrogen production system when the offshore wind power output is small and the green hydrogen production system needs to operate at a low load condition of less than 10%. The load is distributed according to the load distribution equation of the electrolysis hydrogen production system, and the power of the air separation unit, the outlet valve of the hydrogen-ammonia mixing tank and the power of the ammonia synthesis tower are reduced, thereby reducing the amount of hydrogen and ammonia produced; when the offshore wind power is relatively stable and the green hydrogen production system is operating at a load condition of 10-100%, the alkaline electrolysis hydrogen production system is used first and the PEM electrolysis hydrogen production system is used as a supplement. According to the load distribution equation of the electrolysis hydrogen production system, the alkaline electrolysis hydrogen production system is used as a supplement. The alkaline electrolysis hydrogen production system uses pulse current electrolysis mode to meet high-efficiency low-load operation, and uses direct current electrolysis mode to meet high-efficiency high-load operation, and adjusts the air separation unit power, hydrogen-ammonia mixing tank outlet valve and ammonia synthesis tower power accordingly; when the offshore wind power output is large, the green hydrogen production system needs to operate under an overload condition greater than 100%, and the PEM electrolysis hydrogen production system is used to distribute the load according to the load distribution equation of the electrolysis hydrogen production system, and increase the air separation unit power, hydrogen-ammonia mixing tank outlet valve and ammonia synthesis tower power, thereby increasing the amount of hydrogen and ammonia production. Through the above multi-scenario control method, the system can better adapt to the fluctuations of offshore wind power while ensuring the economy of hydrogen and ammonia production.

[0070] The wind power consumption module monitors the operating status and performance data of each electrolytic hydrogen production device in real time through the control system, and dynamically adjusts the hydrogen production power of each electrolytic hydrogen production device according to the principle of allocation according to the operating power ratio; at the same time, the PEM electrolytic hydrogen production system is used as the second-level load response, and the alkaline electrolytic hydrogen production system is used as the minute-level load response.

[0071] Specifically, the energy balance equation of the power generation and heating module includes two parts: the cooler and the fuel cell waste heat exchanger; wherein the energy balance equation of the cooler is:

[0072]

[0073] In the formula, q0 is the mass flow rate of the mixed gas at the inlet of the cooler, η0 is the heat exchange efficiency between the hydrogen-nitrogen mixed gas and the cooling water of the cooler, c0 is the comprehensive specific heat of the mixed gas at the inlet of the cooler, T0 is the temperature of the mixed gas at the inlet of the cooler, ρ0 is the comprehensive density of the mixed gas at the inlet of the cooler, c1 is the comprehensive specific heat of the mixed gas at the outlet of the cooler, T1 is the temperature of the mixed gas at the outlet of the cooler, ρ1 is the comprehensive density of the mixed gas at the outlet of the cooler, q1 is the mass flow rate of the cooling water at the inlet of the cooler, and c 11 is the specific heat of the cooling water at the inlet of the cooler, T 11 is the inlet cooling water temperature of the cooler, ρ 11 is the cooling water density at the inlet of the cooler, c 12 is the specific heat of cooling water at the cooler outlet, T 12 is the outlet cooling water temperature of the cooler, ρ 12 is the cooling water density at the outlet of the cooler.

[0074] The energy balance equation of the fuel cell waste heat exchanger is:

[0075]

[0076] Where q2 is the mass flow rate of the inlet coolant of the fuel cell waste heat exchanger, η2 is the heat exchange efficiency between the coolant and the cooling water of the waste heat exchanger, and c 21 is the specific heat of the inlet coolant of the waste heat exchanger, T 21 is the inlet coolant temperature of the waste heat exchanger, ρ 21 is the inlet coolant density of the waste heat exchanger, c 22 is the outlet coolant specific heat of the waste heat exchanger, T 22 is the outlet coolant temperature of the waste heat exchanger, ρ 22 is the outlet coolant density of the waste heat exchanger, q3 is the inlet cooling water mass flow rate of the fuel cell waste heat exchanger, c 32 is the specific heat of the cooling water at the outlet of the waste heat exchanger, T 32 is the outlet cooling water temperature of the waste heat exchanger, ρ 32 is the cooling water density at the outlet of the waste heat exchanger, c 31 is the specific heat of the cooling water at the inlet of the waste heat exchanger, T 31 is the inlet cooling water temperature of the waste heat exchanger, ρ 31 is the inlet cooling water density of the waste heat exchanger.

[0077] like Figure 3As shown, when the power generation and heating module needs to increase the power generation and maintain stable heat supply, it promotes more liquid ammonia to decompose by increasing the power of the liquid ammonia delivery pump, the opening of the liquid ammonia delivery valve and the power of the ammonia cracker, and increases the flow rate and pressure of hydrogen delivered to the hydrogen fuel cell by increasing the hydrogen nitrogen delivery valve, thereby increasing the power generation. At this time, the waste heat of the cooler and the hydrogen fuel cell of the green ammonia power generation system will increase. Combined with the energy balance equation of the power generation and heating module, the cooling of the cooler is accelerated by increasing the power of the cooler delivery pump and the opening of the cooling water delivery valve, and the cooling of the hydrogen fuel cell is accelerated by increasing the power of the coolant delivery pump, the opening of the coolant valve, and the power of the waste heat exchanger cooling water delivery pump and the opening of the cooling water delivery valve, and the opening of the cold water inlet valve and the hot water outlet valve are increased, thereby achieving stable heat supply;

[0078] When it is necessary to reduce the power generation and maintain a stable heat supply, the liquid ammonia decomposition is reduced by reducing the power of the liquid ammonia delivery pump, the opening of the liquid ammonia delivery valve and the power of the ammonia cracker. The hydrogen flow and pressure delivered to the hydrogen fuel cell are reduced by reducing the hydrogen nitrogen delivery valve, thereby reducing the power generation. At this time, the waste heat of the cooler and hydrogen fuel cell of the green ammonia power generation system will be reduced. Combined with the energy balance equation of the power generation and heating module, stable heat supply can be achieved by reducing the opening of the cold water inlet valve.

[0079] The present invention utilizes offshore wind power to produce green ammonia to promote the consumption of new energy, reduce the investment in the construction of offshore transmission channels, and realize the stable and diversified energy supply by using green ammonia to generate electricity and provide heat. At the same time, through the unique design of electric-ammonia-heat multi-energy conversion system and novel control method, it can effectively adapt to the fluctuation of offshore wind power and realize the economical and efficient production and diversified utilization of green ammonia.

[0080] As described above, it is only a preferred embodiment of the present invention and does not impose any limitation on the present invention. Any simple modification, change and equivalent structural change made to the above embodiment based on the technical essence of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. An electric-ammonia-heat multi-energy conversion system adapting to offshore wind power fluctuations, characterized in that: Including green hydrogen production system, green ammonia synthesis system, green ammonia power generation system and green ammonia heating system; The green hydrogen production system comprises an offshore wind power generation system (1), a seawater desalination system (2), a fresh water tank (3), an alkaline electrolysis hydrogen production system (4), a PEM electrolysis hydrogen production system (5) and a hydrogen buffer tank (6); the seawater desalination system (2) is used to process seawater into fresh water and store the fresh water in the fresh water tank (3); the fresh water from the fresh water tank (3) is respectively fed into the alkaline electrolysis hydrogen production system (4) and the PEM electrolysis hydrogen production system (5); and hydrogen is produced by using the electricity generated by the offshore wind power generation system (1), and the obtained hydrogen is stored in the hydrogen buffer tank (6); The green ammonia synthesis system comprises an air separation device (8), a nitrogen buffer tank (9), a nitrogen compressor (10), a hydrogen compressor (7), a hydrogen-nitrogen mixing tank (11), an ammonia synthesis tower (14), an ammonia cooling tower (15), an ammonia separator (16), a centrifugal pump (17), a liquid ammonia storage tank (18) and a circulating compressor (19); the air separation device (8) is used to separate nitrogen from the air and send the nitrogen into the nitrogen buffer tank (9); the nitrogen in the nitrogen buffer tank (9) is compressed by the nitrogen compressor (10) and then sent to the hydrogen-nitrogen mixing tank (11); the hydrogen in the hydrogen buffer tank (6) is compressed by the hydrogen compressor (10) and then sent to the hydrogen-nitrogen mixing tank (11); After being compressed by the gas compressor (7), the gas mixture is also sent to the hydrogen-nitrogen mixing tank (11). The mixed gas in the hydrogen-nitrogen mixing tank (11) is sent to the ammonia synthesis tower (14) for green ammonia synthesis. The obtained mixed gas of ammonia, nitrogen and hydrogen enters the ammonia cooling tower (15) for cooling. The cooled mixed substance enters the ammonia separator (16) for separation. The mixed gas located at the upper part of the ammonia separator (16) is sent back to the hydrogen-nitrogen mixing tank (11) through the circulation compressor (19) and is used as the raw gas for synthesizing ammonia again. The liquid ammonia located at the lower part of the ammonia separator (16) is sent to the liquid ammonia storage tank (18) through the centrifugal pump (17). The green ammonia power generation system comprises a liquid ammonia delivery pump (21), a liquid ammonia delivery valve (20), a liquid ammonia vaporizer (22), an ammonia pressure reducing valve (23), a heat exchanger (24), an ammonia cracker (25), a cooler (26), a dryer (27), a hydrogen-nitrogen buffer tank (28), a hydrogen-nitrogen delivery valve (29), a hydrogen fuel cell (30) and a DC / AC inverter. The liquid ammonia delivery pump (21) is used to deliver the liquid ammonia in the liquid ammonia storage tank (18) through the liquid ammonia delivery valve (20) to the liquid ammonia vaporizer (22) for vaporization, and the vaporized ammonia gas enters the liquid ammonia vaporizer (22) after passing through the ammonia pressure reducing valve (23). The heat exchanger (24) exchanges heat with the high-temperature hydrogen-nitrogen mixed gas from the ammonia cracker (25), and then enters the ammonia cracker (25) and is decomposed into hydrogen and nitrogen under the action of a catalyst. The hydrogen-nitrogen mixed gas is cooled by the heat exchanger (24) and the cooler (26), and then enters the dryer (27) to remove moisture from the hydrogen-nitrogen mixed gas. The dried hydrogen-nitrogen mixed gas enters the hydrogen-nitrogen buffer tank (28) for storage. The hydrogen-nitrogen mixed gas in the hydrogen-nitrogen buffer tank (28) is sent to the hydrogen fuel cell (30) through the hydrogen-nitrogen delivery valve (29) to generate electricity. The generated electricity is connected to the grid through a DC / AC inverter. The green ammonia heating system comprises a constant temperature water tank (31), a cooler cooling water delivery pump (33), a cooler cooling water delivery valve (32), a fuel cell coolant tank (37), a fuel cell coolant delivery pump (39), a fuel cell coolant delivery valve (38), a fuel cell waste heat exchanger (36), a waste heat exchanger cooling water delivery pump (35) and a waste heat exchanger cooling water delivery valve (34); cold water in the bottom layer of the constant temperature water tank (31) passes through the cooler cooling water delivery pump (33) and the cooler cooling water delivery valve (32) and then enters the coolant tank (37). The heat exchanger (26) is used for heat exchange, and the hot water after heat exchange enters the upper layer of the constant temperature water tank (31); at the same time, the coolant in the fuel cell coolant tank (37) passes through the fuel cell coolant delivery pump (39) and the fuel cell coolant delivery valve (38) and enters the hydrogen fuel cell (30) to be cooled, and the coolant after heat exchange is exchanged with the cooling water from the waste heat exchanger cooling water delivery pump (35) and the waste heat exchanger cooling water delivery valve (34) in the fuel cell waste heat exchanger (36), and the hot water after heat exchange is used to enter the upper layer of the constant temperature water tank (31).

2. The electric-ammonia-heat multi-energy conversion system adapted to offshore wind power fluctuations according to claim 1 is characterized in that: The mixed gas in the hydrogen-nitrogen mixing tank (11) passes through the hydrogen-nitrogen mixing tank outlet valve (12) and is compressed by a multi-stage compressor (13) before being sent to an ammonia synthesis tower (14) for green ammonia synthesis.

3. The electric-ammonia-heat multi-energy conversion system adapted to offshore wind power fluctuations according to claim 1 is characterized in that: The liquid ammonia vaporizer of the green ammonia power generation system is a plate heat exchanger, which vaporizes the liquid ammonia in a water bath using hot water heated by an electric heater to keep the ammonia at 44-46°C and 1.4-1.6MPa. The power of the electric heater and the temperature of the hot water can be adjusted as needed to change the pressure and temperature of the ammonia.

4. The electric-ammonia-heat multi-energy conversion system adapted to offshore wind power fluctuations according to claim 1 is characterized in that: The ammonia cracker of the green ammonia power generation system adopts nickel-chromium alloy with excellent performance at high temperature as an electric heating element, and accurately controls the cracking temperature through an electrical temperature control device. At the same time, a low-temperature Ni-Ru-based ammonia decomposition hydrogen production catalyst is used to achieve more than 99.5% of ammonia decomposition into hydrogen-nitrogen mixed gas at normal pressure and 475-485°C.

5. The control method of the electric-ammonia-heat multi-energy conversion system according to any one of claims 1 to 4, characterized in that: The wind power consumption module and the power generation and heating module are used for control; The wind power consumption module uses an alkaline electrolysis hydrogen production system and a PEM electrolysis hydrogen production system in combination, and adjusts the power of the air separation unit, the outlet valve of the hydrogen-nitrogen mixing tank and the power of the ammonia synthesis tower to effectively adapt to offshore wind power fluctuations; The power generation and heating module realizes power generation change by adjusting the power of the liquid ammonia delivery pump, the liquid ammonia delivery valve, the ammonia cracker power and the hydrogen-nitrogen delivery valve, and realizes precise temperature control by adjusting the cold water inlet valve of the constant temperature water tank, the hot water outlet valve of the constant temperature water tank, the cooler cooling water delivery valve and the waste heat exchanger cooling water delivery valve.

6. The control method according to claim 5, characterized in that: The load distribution equation of the electrolysis hydrogen production system of the wind power consumption module includes the total power equation of the electrolysis hydrogen production system, the load distribution equation of the PEM electrolysis hydrogen production system and the load distribution equation of the alkaline electrolysis hydrogen production system; among which, the total power equation of the electrolysis hydrogen production system is: In the formula, P0 is the total power of the electrolytic hydrogen production system, n is the total number of PEM electrolytic hydrogen production devices, α 1i is the workload of the ith PEM electrolysis hydrogen production device, P 1i is the rated power of the ith PEM electrolysis hydrogen production device, m is the total number of alkaline electrolysis hydrogen production devices, α 2j is the workload of the jth alkaline electrolysis hydrogen production unit, P 2j is the rated power of the jth alkaline electrolysis hydrogen production device; The load distribution equation of the PEM electrolysis hydrogen production system is: Where P1 is the actual total operating power of the PEM electrolysis hydrogen production system, P 1t is the power required by the PEM electrolysis hydrogen production system, P 1min is the minimum single rated power of the PEM electrolysis hydrogen production device, α 11 is the workload of the PEM electrolysis hydrogen production device with the minimum rated power, k is the number of PEM electrolysis hydrogen production devices operating at rated power, α 12 is the fixed value of the PEM electrolysis hydrogen production device between 0-100% of the working load, α 13 It is the set value of the PEM electrolysis hydrogen production device between 100% and 160% of the working load; The load distribution equation of the alkaline electrolysis hydrogen production system is: Where P2 is the actual total operating power of the alkaline electrolysis hydrogen production system, P 2t is the power required by the alkaline electrolysis hydrogen production system, P 2min is the minimum single rated power of the alkaline electrolysis hydrogen production device, α 21 is the workload of the alkaline electrolysis hydrogen production unit at the minimum rated power, h is the number of alkaline electrolysis hydrogen production units operating at rated power, α 22 It is the set value of the alkaline electrolysis hydrogen production device between 10% and 100% of the working load.

7. The control method according to claim 6, characterized in that: The wind power consumption module uses the PEM electrolysis hydrogen production system when the offshore wind power output is small and the green hydrogen production system needs to operate at a low load of less than 10%. The load is distributed according to the load distribution equation of the electrolysis hydrogen production system, and the power of the air separation unit, the outlet valve of the hydrogen-ammonia mixing tank and the power of the ammonia synthesis tower are reduced, thereby reducing the amount of hydrogen and ammonia produced. When the offshore wind power is relatively stable and the green hydrogen production system is operating at a load of 10-100%, the alkaline electrolysis hydrogen production system is used first and the PEM electrolysis hydrogen production system is used as a supplement. The load distribution equation of the electrolysis hydrogen production system is used. The alkaline electrolysis hydrogen production system adopts pulse current electrolysis mode to meet the requirements of high-efficiency and low-load operation, and adopts direct current electrolysis mode to meet the requirements of high-efficiency and high-load operation, and adjusts the power of the air separation unit, the outlet valve of the hydrogen-ammonia mixing tank and the power of the ammonia synthesis tower accordingly; when the offshore wind power output is large and the green hydrogen production system needs to operate under an overload condition greater than 100%, the PEM electrolysis hydrogen production system is used to distribute the load according to the load distribution equation of the hydrogen electrolysis system, and increase the power of the air separation unit, the outlet valve of the hydrogen-ammonia mixing tank and the power of the ammonia synthesis tower, thereby increasing the amount of hydrogen and ammonia produced.

8. The control method according to claim 7, characterized in that: The wind power consumption module monitors the operating status and performance data of each electrolytic hydrogen production device in real time through the control system, and dynamically adjusts the hydrogen production power of each electrolytic hydrogen production device according to the principle of allocation according to the operating power ratio; at the same time, the PEM electrolytic hydrogen production system is used as the second-level load response, and the alkaline electrolytic hydrogen production system is used as the minute-level load response.

9. The control method according to claim 5, characterized in that: The energy balance equation of the power generation and heating module includes two parts: the cooler and the fuel cell waste heat exchanger; the energy balance equation of the cooler is: In the formula, q0 is the mass flow rate of the mixed gas at the inlet of the cooler, η0 is the heat exchange efficiency between the hydrogen-nitrogen mixed gas and the cooling water of the cooler, c0 is the comprehensive specific heat of the mixed gas at the inlet of the cooler, T0 is the temperature of the mixed gas at the inlet of the cooler, ρ0 is the comprehensive density of the mixed gas at the inlet of the cooler, c1 is the comprehensive specific heat of the mixed gas at the outlet of the cooler, T1 is the temperature of the mixed gas at the outlet of the cooler, ρ1 is the comprehensive density of the mixed gas at the outlet of the cooler, q1 is the mass flow rate of the cooling water at the inlet of the cooler, and c 11 is the specific heat of the cooling water at the inlet of the cooler, T 11 is the inlet cooling water temperature of the cooler, ρ 11 is the cooling water density at the cooler inlet, c 12 is the specific heat of cooling water at the cooler outlet, T 12 is the outlet cooling water temperature of the cooler, ρ 12 is the cooling water density at the outlet of the cooler; The energy balance equation of the fuel cell waste heat exchanger is: Where q2 is the mass flow rate of the inlet coolant of the fuel cell waste heat exchanger, η2 is the heat exchange efficiency between the coolant and the cooling water of the waste heat exchanger, and c 21 is the specific heat of the inlet coolant of the waste heat exchanger, T 21 is the inlet coolant temperature of the waste heat exchanger, ρ 21 is the inlet coolant density of the waste heat exchanger, c 22 is the outlet coolant specific heat of the waste heat exchanger, T 22 is the outlet coolant temperature of the waste heat exchanger, ρ 22 is the outlet coolant density of the waste heat exchanger, q3 is the inlet cooling water mass flow rate of the fuel cell waste heat exchanger, c 32 is the specific heat of the cooling water at the outlet of the waste heat exchanger, T 32 is the outlet cooling water temperature of the waste heat exchanger, ρ 32 is the cooling water density at the outlet of the waste heat exchanger, c 31 is the specific heat of the inlet cooling water of the waste heat exchanger, T 31 is the inlet cooling water temperature of the waste heat exchanger, ρ 31 is the inlet cooling water density of the waste heat exchanger.

10. The control method according to claim 9, characterized in that: The power generation and heating module, when it is necessary to increase the power generation and maintain stable heat supply, promotes the decomposition of more liquid ammonia by increasing the power of the liquid ammonia delivery pump, the opening of the liquid ammonia delivery valve and the power of the ammonia cracker, and increases the flow rate and pressure of hydrogen delivered to the hydrogen fuel cell by increasing the hydrogen nitrogen delivery valve, thereby increasing the power generation. At this time, the waste heat of the cooler and the hydrogen fuel cell of the green ammonia power generation system will increase. Combined with the energy balance equation of the power generation and heating module, the cooling of the cooler is accelerated by increasing the power of the cooler delivery pump and the opening of the cooling water delivery valve, and the cooling of the hydrogen fuel cell is accelerated by increasing the power of the coolant delivery pump, the opening of the coolant valve, and the power of the waste heat exchanger cooling water delivery pump and the opening of the cooling water delivery valve, and the opening of the cold water inlet valve and the hot water outlet valve are increased, thereby achieving stable heat supply; When it is necessary to reduce the power generation and maintain a stable heat supply, the liquid ammonia decomposition is reduced by reducing the power of the liquid ammonia delivery pump, the opening of the liquid ammonia delivery valve and the power of the ammonia cracker. The hydrogen flow and pressure delivered to the hydrogen fuel cell are reduced by reducing the hydrogen nitrogen delivery valve, thereby reducing the power generation. At this time, the waste heat of the cooler and hydrogen fuel cell of the green ammonia power generation system will be reduced. Combined with the energy balance equation of the power generation and heating module, stable heat supply can be achieved by reducing the opening of the cold water inlet valve.

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