Ammonia internal combustion engine system coupling tail gas treatment and waste heat utilization and control method thereof

Abstract

The invention discloses an ammonia internal combustion engine system coupling tail gas treatment and waste heat utilization and a control method of the ammonia internal combustion engine system. The ammonia internal combustion engine system comprises a fuel supply system, an air supply system, a waste heat utilization system, a tail gas treatment system and an internal combustion engine power generation system. According to the ammonia internal combustion engine system, the combustion power generation module, the tail gas treatment module and the waste heat utilization module are adopted for control, the combustion power generation module achieves safe and efficient combustion of different fuels by controlling the operation mode of the ammonia internal combustion engine system, and the tail gas treatment module achieves clean and low-nitrogen emission by controlling the tail gas treatment mode with different NOx contents. The waste heat utilization module improves the overall energy efficiency of the ammonia internal combustion engine system by controlling three-stage efficient heat exchange. According to the ammonia internal combustion engine system, the purposes of stable and efficient combustion, comprehensive efficiency improvement, clean and low-nitrogen emission and the like are achieved; through the unique control method, the system can effectively adapt to various operation modes of the ammonia internal combustion engine system, and clean, safe and efficient power generation of the ammonia internal combustion engine system is achieved.

Description

Technical Field

[0001] The present invention relates to an ammonia internal combustion engine system, and more particularly to an ammonia internal combustion engine system for coupling tail gas treatment and waste heat utilization and a control method thereof. Background Art

[0002] The potential for carbon dioxide reduction is huge. It is urgent to promote carbon reduction in the power industry by replacing fossil fuels with renewable clean fuels, and to drive the transformation of terminal energy consumption from mainly electricity substitution to diversified clean substitution of electricity, hydrogen, ammonia, etc., so as to promote the construction of a new power system.

[0003] Ammonia is a safe carbon-free fuel with a mature storage and transportation system, low storage and transportation costs, and a wide range of utilization methods. By producing green ammonia from renewable energy and using green ammonia to replace fossil fuels such as coal, gasoline, and diesel for clean power generation, the use of fossil fuels can be effectively reduced, stable and efficient fuel power generation and clean and low-carbon emissions can be achieved, thereby reducing carbon emissions in the power industry and promoting the realization of the national dual-carbon goal.

[0004] Currently, in the process of realizing ammonia internal combustion engine power generation, there are problems such as unstable combustion, low energy utilization efficiency, and high nitrogen oxide emissions.

[0005] Inventive Patent

[0006] Aiming at the problems of unstable combustion, low energy utilization efficiency, and high nitrogen oxide emissions in the existing ammonia internal combustion engine system, the present invention provides an ammonia internal combustion engine and a control method for coupling tail gas treatment and waste heat utilization, so as to achieve the goals of stable and efficient combustion, improved comprehensive efficiency, and clean and low-nitrogen emissions.

[0007] To this end, the technical solution adopted by the present invention is as follows.

[0008] In a first aspect, the present invention provides an ammonia internal combustion engine system for coupling tail gas treatment and waste heat utilization, which includes a fuel supply system, an air supply system, a waste heat utilization system, a tail gas treatment system, and an internal combustion engine power generation system;

[0009] The fuel supply system includes a liquid ammonia tank, a liquid ammonia transfer pump, an ammonia direct supply valve, an ammonia cracker, a mixed gas transfer valve, a mixed gas purification valve, a hydrogen purifier, a hydrogen buffer tank, and a hydrogen transfer valve; the liquid ammonia in the liquid ammonia tank is sent out by the liquid ammonia transfer pump, forms ammonia gas after primary preheating and vaporization and secondary reheating. A part of the ammonia gas is mixed with air through the ammonia direct supply valve and sent into the internal combustion engine power generation system for combustion power generation. Another part of the ammonia gas is sent into the ammonia cracker for decomposition to form a hydrogen-ammonia-nitrogen mixed gas after three times of heating. A part of the hydrogen-ammonia-nitrogen mixed gas is mixed with air through the mixed gas transfer valve and sent into the internal combustion engine power generation system. Another part of the hydrogen-ammonia-nitrogen mixed gas enters the hydrogen purifier through the mixed gas purification valve, obtains pure hydrogen and stores it in the hydrogen buffer tank, and transports hydrogen to the internal combustion engine power generation system through the hydrogen transfer valve as needed;

[0010] The air supply system includes an air filter, an air throttle valve, and an air throttle valve position sensor; outside air passes through the air filter to remove impurity particles in the air, and the clean air then enters the air throttle valve and is subjected to real-time flow monitoring and control through the air throttle valve position sensor. The air flowing out of the air throttle valve is sent into the internal combustion engine power generation system;

[0011] The waste heat utilization system includes an ammonia preheater, an ammonia preheater inlet valve, a jacket water heat exchange inlet valve, an ammonia reheater, an ammonia reheater inlet valve, an ammonia tertiary heater, and an ammonia tertiary heating inlet valve; the liquid ammonia transported by the liquid ammonia transfer pump enters the ammonia preheater through the ammonia preheater inlet valve, and the liquid ammonia exchanges heat and vaporizes with the jacket water flowing out of the jacket water heat exchange inlet valve. At the same time, the vaporized ammonia gas enters the ammonia reheater through the ammonia reheater inlet valve to perform secondary heat exchange with the treated tail gas, and the heated ammonia gas enters the ammonia tertiary heater through the ammonia tertiary heating inlet valve for tertiary heating, and the heated ammonia gas enters the ammonia cracker for decomposition;

[0012] The tail gas treatment system includes an original tail gas outlet valve, an SCR processor, an injection cabinet, a spray gun, and an ammonia injection inlet valve; the liquid ammonia from the liquid ammonia tank enters the injection cabinet through the ammonia injection inlet valve, the injection cabinet controls the ammonia flow rate and sprays it into the SCR processor through the spray gun, and the tail gas from the internal combustion engine power generation system enters the ammonia tertiary heater through the original tail gas outlet valve to heat the ammonia gas, and then undergoes denitrification treatment through the SCR processor;

[0013] The internal combustion engine power generation system includes an engine, a generator, a nozzle, an ignition coil, a distributor, a spark plug, a storage battery, a rectifier, and an intake pressure regulating valve; the air coming out of the air supply system and the hydrogen-ammonia-nitrogen mixture coming out of the fuel supply system are mixed and enter the engine through the intake pressure regulating valve and the nozzle, and after being ignited by the ignition coil, the distributor, and the spark plug, combustion occurs, converting chemical energy into mechanical energy, and power generation is carried out through the generator. Most of the generated electricity is connected to the grid, and a small part of the electricity is converted through the rectifier and enters the storage battery for electricity storage, and the storage battery supplies power to electrical equipment.

[0014] Furthermore, the waste heat utilization system further includes a jacket water return temperature sensor and a tail gas post-heat exchange temperature sensor, and the jacket water return temperature sensor and the tail gas post-heat exchange temperature sensor are respectively used to monitor the jacket water temperature and the tail gas temperature after heat exchange.

[0015] Further, the tail gas treatment system further includes a tail gas discharge outlet valve, a tail gas secondary treatment inlet valve, a front temperature sensor, a front NOx sensor, a rear NOx sensor, and a muffler. The front temperature sensor is used to monitor the inlet tail gas temperature of the SCR processor. The front NOx sensor and the rear NOx sensor are used to monitor the NOx content of the inlet and outlet tail gas of the SCR processor. If the NOx content of the outlet tail gas after primary treatment is too high, it will re-enter the SCR processor through the tail gas secondary treatment inlet valve for tail gas treatment. If the NOx content requirement of the outlet tail gas is met, the tail gas will exchange heat with the liquid ammonia in the ammonia reheater through the tail gas discharge outlet valve to cool down, and then be discharged to the atmosphere through the muffler.

[0016] Further, the ammonia cracker of the fuel supply system is electrically heated and temperature-controlled, using a low-temperature Ni-Ru-based ammonia decomposition hydrogen production catalyst, cracking at normal pressure and a temperature of 200-500 °C according to the hydrogen-ammonia fuel supply demand, and being powered by the storage battery of the internal combustion engine power generation system.

[0017] Further, the SCR processor of the tail gas treatment system is electrically heated and temperature-controlled, using platinum and palladium catalysts, and performing selective catalytic reduction denitrification in the temperature range of 200-300 °C according to the tail gas treatment demand, and being powered by the storage battery of the internal combustion engine power generation system.

[0018] Another technical solution provided by the present invention is: the control method of the above ammonia internal combustion engine system, which is controlled by a combustion power generation module, a tail gas treatment module, and a waste heat utilization module; the combustion power generation module realizes the safe and efficient combustion of different fuels by controlling the operation mode of the ammonia internal combustion engine system, the tail gas treatment module realizes clean and low-nitrogen emissions by controlling the tail gas treatment mode of different NOx contents, and the waste heat utilization module realizes the overall energy efficiency improvement of the ammonia internal combustion engine system by controlling three-stage high-efficiency heat exchange.

[0019] Further, the energy balance equation of the waste heat utilization module includes three parts: an ammonia preheater, an ammonia reheater, and an ammonia three-stage heater; among them, the energy balance equation of the ammonia preheater is:

[0020] q0*c0(T 02 -T 01 )+q0*Q0+q0*c2(T 002 -T 02 )=q1*c1*η1*(T 11 -T 12 )

[0021] In the formula, q0 is the inlet liquid ammonia mass flow rate of the ammonia preheater, c0 is the inlet liquid ammonia specific heat of the ammonia preheater, T 01 is the inlet liquid ammonia temperature of the ammonia preheater, T 02is the vaporization temperature of liquid ammonia, Q0 is the latent heat of vaporization of liquid ammonia, c2 is the specific heat of gaseous ammonia, T 002 is the outlet ammonia gas temperature of the ammonia preheater, q1 is the inlet jacket water mass flow rate of the ammonia preheater, c1 is the specific heat of the inlet jacket water of the ammonia preheater, η1 is the heat transfer efficiency between liquid ammonia and jacket water of the ammonia preheater, T 11 is the inlet jacket water temperature of the ammonia preheater, T 12 is the jacket water return temperature of the ammonia preheater;

[0022] The energy balance equation of the ammonia reheater is:

[0023] q0*c2*(T 22 -T 21 ) = η2*(q3*(c3*(T 31 -100)+c4*(100-T 32 ))+c1*q 33 *(100-T 32 )+q 33 *Q1)

[0024] c3 = c 31 *M 31 +c 32 *M 32 +c 33 *M 33 +c 34 *M 34 +c 35 *M 35

[0025] c4 = c 31 *M 31 +c 32 *M 32 +c 33 *M 33 +c 34 *M 34 +c 35 *M 36

[0026] In the formula, T 22 is the outlet ammonia gas temperature of the ammonia reheater, T 21 is the inlet ammonia gas temperature of the ammonia reheater, η2 is the heat transfer efficiency between ammonia gas and high-temperature tail gas of the ammonia reheater, q3 is the inlet tail gas mass flow rate of the ammonia reheater, c3 is the comprehensive specific heat of the inlet tail gas, T 31 is the inlet tail gas temperature of the ammonia reheater, c4 is the comprehensive specific heat of the outlet tail gas, T 32 is the outlet tail gas temperature of the ammonia reheater, q 33 is the mass rate of water vapor condensation in the tail gas, Q1 is the latent heat of vaporization of water, c 31 is the specific heat of nitrogen, M31 is the mass content of nitrogen in the tail gas, c 32 is the specific heat of nitric oxide, M 32 is the mass content of nitric oxide in the tail gas, c 33 is the specific heat of nitrogen dioxide, M 33 is the mass content of nitrogen dioxide in the tail gas, c 34 is the specific heat of oxygen, M 34 is the mass content of oxygen in the tail gas, c 35 is the specific heat of water vapor, M 35 is the mass content of water vapor in the inlet tail gas, M 36 is the mass content of water vapor in the outlet tail gas;

[0027] The energy balance equation of the ammonia three-stage heater is

[0028] q4 * c2 * (T 42 - T 41 ) = q5 * η4 * (c 31 * M 51 + c 32 * M 52 + c 33 * M 53 + c 34 * M 54 + c 35 * M 55 ) * (T 51 - T 52 )

[0029] In the formula, q4 is the inlet ammonia mass flow rate of the ammonia three-stage heater, T 42 is the outlet ammonia temperature of the ammonia three-stage heater, T 41 is the inlet ammonia temperature of the ammonia three-stage heater, q5 is the inlet raw tail gas mass flow rate of the ammonia three-stage heater, η4 is the heat exchange efficiency of ammonia and high-temperature raw tail gas in the ammonia three-stage heater, M 51 is the mass content of nitrogen in the raw tail gas, M 52 is the mass content of nitric oxide in the raw tail gas, M 53 is the mass content of nitrogen dioxide in the raw tail gas, M 54 is the mass content of oxygen in the raw tail gas, M 55 is the mass content of water vapor in the raw tail gas, T 51 is the inlet tail gas temperature of the ammonia three-stage heater, T 52 is the outlet tail gas temperature of the ammonia three-stage heater.

[0030] Furthermore, the combustion power generation module performs the following steps:

[0031] Step 11, determine whether the ammonia internal combustion engine system needs pure ammonia combustion, pure hydrogen combustion, or ammonia-hydrogen mixed combustion. If the ammonia internal combustion engine system needs pure ammonia combustion, then execute Step 12. If the ammonia internal combustion engine system needs pure hydrogen combustion, then execute Step 13. If the ammonia internal combustion engine system needs ammonia-hydrogen mixed combustion, then execute Step 14;

[0032] Step 12, the liquid ammonia in the liquid ammonia tank enters the ammonia preheater and ammonia reheater for heating. All the heated ammonia gas is sent into the internal combustion engine power generation system for combustion power generation after being mixed with air through the ammonia direct supply valve. The air and ammonia gas flow rates are appropriately adjusted through the air throttle valve and ammonia direct current valve. The volume flow rate ratio of air to ammonia is 6.5 - 7.5:1. At this time, the ammonia preheater inlet valve, ammonia reheater inlet valve, ammonia direct supply valve, air throttle valve, and intake pressure regulating valve are in the open state, and the ammonia three-stage heating inlet valve, mixed gas delivery valve, mixed gas purification valve, hydrogen delivery valve, and ammonia reheater inlet valve are in the closed state;

[0033] Step 13, the liquid ammonia in the liquid ammonia tank enters the ammonia preheater and ammonia reheater for heating. All the heated ammonia gas enters the ammonia three-stage heater for three-stage heating, and then is sent into the ammonia cracker to decompose into a hydrogen-ammonia-nitrogen mixed gas. The mixed gas is all purified through the hydrogen purifier and stored in the hydrogen buffer tank. The hydrogen in the hydrogen buffer tank is sent into the internal combustion engine power generation system for combustion power generation after being mixed with air through the hydrogen delivery valve. The air and hydrogen gas flow rates are appropriately adjusted through the throttle valve and hydrogen delivery valve. The volume flow rate ratio of air to hydrogen is 9.5 - 10.5:1. At this time, the ammonia preheater inlet valve, ammonia reheater inlet valve, ammonia three-stage heating inlet valve, mixed gas purification valve, hydrogen delivery valve, air throttle valve, and intake pressure regulating valve are in the open state, and the ammonia direct supply valve and mixed gas delivery valve are in the closed state;

[0034] Step 4, the liquid ammonia in the liquid ammonia tank enters the ammonia preheater and ammonia reheater for heating. All the heated ammonia gas enters the ammonia three-stage heater for three-stage heating, and then is sent into the ammonia cracker to decompose into a hydrogen-ammonia-nitrogen mixed gas. The mixed gas is all sent into the internal combustion engine power generation system through the mixed gas delivery valve. The hydrogen-ammonia ratio in the mixed gas is changed through the ammonia decomposition hydrogen production catalyst and cracking temperature. The air and mixed gas flow rates are appropriately adjusted through the throttle valve and mixed gas delivery valve. At this time, the ammonia preheater inlet valve, ammonia reheater inlet valve, ammonia three-stage heating inlet valve, mixed gas delivery valve, air throttle valve, and intake pressure regulating valve are in the open state, and the ammonia direct supply valve, mixed gas purification valve, and hydrogen delivery valve are in the closed state.

[0035] Furthermore, the tail gas treatment module executes the following steps:

[0036] Step 21, monitor whether the NOx content of the original exhaust gas of the engine detected by the front NOx sensor meets the emission requirements. If the NOx content of the original exhaust gas is too high, then execute Step 22, otherwise execute Step 24;

[0037] Step 22: Open the ammonia injection inlet valve to allow liquid ammonia to enter the injection cabinet. Control the injection cabinet to increase the liquid ammonia flow rate sprayed by the spray gun into the SCR processor. Use the electric heating temperature control of the SCR processor to maintain the denitrification temperature within the range of 200 - 300 °C, and monitor whether the NOx content in the treated tail gas meets the emission requirements through the post NOx sensor. If it is too high, execute Step 23; otherwise, execute Step 24;

[0038] Step 23: Close the tail gas emission outlet valve and open the tail gas secondary treatment inlet valve to allow the treated tail gas to re-enter the SCR processor for secondary tail gas treatment, and repeat Step 22;

[0039] Step 24: Close the tail gas secondary treatment inlet valve and open the tail gas emission outlet valve. The treated tail gas enters the ammonia reheater, exchanges heat with ammonia in the ammonia reheater to reduce the temperature, and then is discharged to the atmosphere.

[0040] Furthermore, the waste heat utilization module performs the following steps:

[0041] Step 31: Monitor whether the temperature of the jacket water return is higher than 85 °C through the jacket water return temperature sensor. If it is too high, execute Step 32; otherwise, execute Step 33;

[0042] Step 32: Based on the energy balance equation of the ammonia preheater, increase the ammonia flow rate entering the ammonia preheater by increasing the opening degree of the ammonia preheater inlet valve, and reduce the jacket water flow rate entering the ammonia preheater by reducing the opening degree of the jacket water heat exchange inlet valve, so as to accelerate the cooling of the jacket water;

[0043] Step 33: Monitor whether the original exhaust gas of the engine is higher than 300 °C through the pre-temperature sensor. If it is too high, execute Step 34; otherwise, execute Step 35;

[0044] Step 34: Based on the energy balance equation of the ammonia three-stage heater, increase the ammonia flow rate entering the ammonia three-stage heater by increasing the opening degree of the ammonia three-stage heater inlet valve and reducing the opening degree of the ammonia direct supply valve, and reduce the exhaust gas flow rate entering the ammonia three-stage heater by reducing the original exhaust gas outlet valve, so as to accelerate the cooling of the high-temperature original exhaust gas;

[0045] Step 35: Monitor whether the treated exhaust gas temperature is higher than 100 °C through the post-temperature sensor. If it is too high, execute Step 36; otherwise, execute Step 37;

[0046] Step 36: Based on the energy balance equation of the ammonia reheater, increase the liquid ammonia flow rate by increasing the power of the liquid ammonia transfer pump and the opening degree of the ammonia reheater inlet valve, and reduce the exhaust gas flow rate by reducing the opening degree of the exhaust gas emission outlet valve, so as to accelerate the cooling of the treated exhaust gas;

[0047] Step 37: The liquid ammonia transfer pump maintains its current power, and the inlet valve of the ammonia reheater and the outlet valve of the tail gas emission maintain their current opening degrees.

[0048] The beneficial effects of the present invention are as follows:

[0049] 1. By using green ammonia produced from renewable energy to replace fossil fuels such as coal, gasoline, and diesel, the use of fossil fuels can be effectively reduced, stable and efficient fuel power generation and clean and low-carbon emissions can be achieved, thereby reducing carbon emissions in the power industry.

[0050] 2. The innovative design of the ammonia internal combustion engine system effectively adapts to various operating modes of the internal combustion engine and realizes safe and efficient combustion power generation through the coupled use of the combustion supply system, air supply system, and internal combustion engine power generation system; the overall energy utilization efficiency is improved through the three-stage waste heat utilization system; the online monitoring of the tail gas and clean and low-nitrogen emissions are realized through the tail gas treatment system, achieving clean, safe, and efficient power generation of the ammonia internal combustion engine system.

[0051] 3. In the control method of the ammonia internal combustion engine system, the control logics of combustion power generation, tail gas treatment, and waste heat utilization are clear. The combustion power generation module realizes the safe and efficient combustion of different fuels by controlling the operating mode of the internal combustion engine system. The tail gas treatment module realizes clean and low-nitrogen emissions by controlling the tail gas treatment modes with different NO x content. The waste heat utilization module improves the overall energy utilization efficiency of the ammonia internal combustion engine system by controlling the three-stage high-efficiency heat exchange.

[0052] 4. The ammonia internal combustion engine system has a unique design and a novel and effective control method. Each part can be used according to the design idea or can be appropriately adjusted to ensure stable and efficient combustion power generation, improvement of the overall energy utilization efficiency, clean and low-nitrogen emissions, etc. Description of the Drawings

[0053] Figure 1 is a schematic structural diagram of the ammonia internal combustion engine system coupling tail gas treatment and waste heat utilization of the present invention;

[0054] In the figure, 1 - liquid ammonia tank; 2 - liquid ammonia transfer pump; 3 - ammonia preheater inlet valve; 4 - ammonia preheater; 5 - ammonia reheater inlet valve; 6 - ammonia reheater; 7 - ammonia direct delivery valve; 8 - ammonia three - stage heating inlet valve; 9 - ammonia three - stage heater; 10 - ammonia cracker; 11 - mixed gas transfer valve; 12 - mixed gas purification valve; 13 - hydrogen purifier; 14 - hydrogen buffer tank; 15 - hydrogen transfer valve; 16 - air filter; 17 - air throttle valve; 18 - air throttle valve position sensor; 19 - intake pressure regulating valve; 20 - nozzle; 21 - ignition coil; 22 - distributor; 23 - spark plug; 24 - engine; 25 - generator; 26 - rectifier; 27 - battery; 28 - original exhaust gas outlet valve; 29 - front temperature sensor; 30 - front NOx sensor; 31 - SCR processor; 32 - rear NOx sensor; 33 - exhaust gas secondary treatment inlet valve; 34 - ammonia injection inlet valve; 35 - injection cabinet; 36 - spray gun; 37 - exhaust gas discharge outlet valve; 38 - exhaust gas temperature sensor after heat exchange; 39 - muffler; 40 - cylinder jacket water heat exchange inlet valve; 41 - cylinder jacket water return temperature sensor;

[0055] Figure 2 is the logic control diagram of the combustion power generation module of the present invention;

[0056] Figure 3 is the logic control diagram of the exhaust gas treatment module of the present invention;

[0057] Figure 4 is the logic control diagram of the waste heat utilization module of the present invention. Detailed implementation manners

[0058] The present invention will be described in detail below with reference to the accompanying drawings of the specification and specific embodiments. The embodiments of the present invention are implemented on the premise of the technical solution of the present invention, and detailed implementation manners and specific operation processes are given, but the protection scope of the present invention is not limited to the following embodiments.

[0059] Embodiment 1

[0060] This embodiment provides an ammonia internal combustion engine system that couples exhaust gas treatment and waste heat utilization, which includes a fuel supply system, an air supply system, a waste heat utilization system, an exhaust gas treatment system, and an internal combustion engine power generation system, as Figure 1 shown.

[0061] The fuel supply system includes a liquid ammonia tank 1, a liquid ammonia transfer pump 2, an ammonia direct supply valve 7, an ammonia cracker 10, a mixed gas transfer valve 11, a mixed gas purification valve 12, a hydrogen purifier 13, a hydrogen buffer tank 14, and a hydrogen transfer valve 15. The liquid ammonia in the liquid ammonia tank 1 is sent out by the liquid ammonia transfer pump 2, forms ammonia gas after primary preheating vaporization and secondary reheating. A part of the ammonia gas is mixed with air through the ammonia direct supply valve 7 and sent into the internal combustion engine power generation system for combustion power generation. Another part of the ammonia gas is sent into the ammonia cracker 10 for decomposition to form a hydrogen-ammonia-nitrogen mixed gas after three-stage heating. A part of the hydrogen-ammonia-nitrogen mixed gas is mixed with air through the mixed gas transfer valve 11 and sent into the internal combustion engine power generation system. Another part of the hydrogen-ammonia-nitrogen mixed gas enters the hydrogen purifier 13 through the mixed gas purification valve 12 to obtain pure hydrogen, which is stored in the hydrogen buffer tank 14, and the hydrogen is transferred to the internal combustion engine power generation system through the hydrogen transfer valve 15 as needed.

[0062] The air supply system includes an air filter 16, an air throttle valve 17, and an air throttle valve position sensor 18. The outside air passes through the air filter 16 to remove the impurity particles in the air. The clean air then enters the air throttle valve 17 and the flow rate is monitored and controlled in real time through the air throttle valve position sensor 18. The air flowing out of the air throttle valve 17 is sent into the internal combustion engine power generation system.

[0063] The waste heat utilization system includes an ammonia preheater 4, an ammonia preheater inlet valve 3, a jacket water heat exchange inlet valve 40, an ammonia reheater 6, an ammonia reheater inlet valve 5, an ammonia tertiary heater 9, an ammonia tertiary heating inlet valve 8, a jacket water return temperature sensor 41, and a tail gas heat exchange post-temperature sensor 38. The liquid ammonia transported by the liquid ammonia transfer pump 2 enters the ammonia preheater 4 through the ammonia preheater inlet valve 3, and the liquid ammonia exchanges heat with the jacket water flowing out of the jacket water heat exchange inlet valve 40 for vaporization. At the same time, the vaporized ammonia gas enters the ammonia reheater 6 through the ammonia reheater inlet valve 5 for secondary heat exchange with the treated tail gas. The heated ammonia gas enters the ammonia tertiary heater 9 through the ammonia tertiary heating inlet valve 8 for three-stage heating, and the heated ammonia gas enters the ammonia cracker 10 for decomposition. The jacket water return temperature sensor 41 and the tail gas heat exchange post-temperature sensor 38 are respectively used to monitor the jacket water temperature and the tail gas temperature after heat exchange.

[0064] The tail gas treatment system includes an original tail gas outlet valve 28, an SCR processor 31, an injection cabinet 35, a spray gun 36, an ammonia injection inlet valve 34, a tail gas discharge outlet valve 37, a tail gas secondary treatment inlet valve 33, a front temperature sensor 29, a front NOx sensor 30, a rear NOx sensor 32, and a muffler 39; the liquid ammonia from the liquid ammonia tank 1 enters the injection cabinet 35 through the ammonia injection inlet valve 34, the injection cabinet 35 controls the ammonia flow rate and sprays it into the SCR processor 31 through the spray gun 36, the tail gas from the internal combustion engine power generation system enters the ammonia triple heater through the original tail gas outlet valve 28 to heat the ammonia, and then undergoes denitrification treatment through the SCR processor 31. The front temperature sensor 29 is used to monitor the inlet tail gas temperature of the SCR processor 31, and the front NOx sensor 30 and the rear NOx sensor 32 are used to monitor the inlet and outlet tail gas NOx contents of the SCR processor 31. If the NOx content of the outlet tail gas after primary treatment is too high, it re-enters the SCR processor 31 through the tail gas secondary treatment inlet valve 33 for tail gas treatment. If the outlet tail gas NOx content requirement is met, the tail gas passes through the tail gas discharge outlet valve 37, exchanges heat with the liquid ammonia in the ammonia reheater 6 to cool down, and then is discharged to the atmosphere through the muffler 39.

[0065] The internal combustion engine power generation system includes an engine 24, a generator 25, a nozzle 20, an ignition coil 21, a distributor 22, a spark plug 23, a storage battery 27, a rectifier 26, and an intake pressure regulating valve 19; the air from the air supply system and the hydrogen-ammonia-nitrogen mixed gas from the fuel supply system are mixed and enter the engine 24 through the intake pressure regulating valve 19 and the nozzle 20, and after being ignited by the ignition coil 21, the distributor 22, and the spark plug 23, combustion occurs, converting chemical energy into mechanical energy, and generating electricity through the generator 25. Most of the generated electricity is grid-connected, and a small part of the electricity is converted through the rectifier 26 and enters the storage battery 27 for electricity storage, and the storage battery 27 supplies power to the electrical equipment.

[0066] The ammonia cracker of the fuel supply system is electrically heated and temperature-controlled, uses a low-temperature Ni-Ru-based ammonia decomposition hydrogen production catalyst, undergoes cracking at normal pressure and a temperature of 200 - 500 °C according to the hydrogen-ammonia fuel supply demand, and is powered by the storage battery of the internal combustion engine power generation system.

[0067] The SCR processor of the tail gas treatment system is electrically heated and temperature-controlled, uses platinum and palladium catalysts, and performs selective catalytic reduction denitrification in the temperature range of 200 - 300 °C according to the tail gas treatment demand, and is powered by the storage battery of the internal combustion engine power generation system.

[0068] Example 2

[0069] This embodiment provides a control method for the ammonia internal combustion engine system described in Embodiment 1, which is controlled by a combustion power generation module, an exhaust gas treatment module, and a waste heat utilization module; the combustion power generation module realizes the safe and efficient combustion of different fuels by controlling the operation mode of the ammonia internal combustion engine system, the exhaust gas treatment module realizes clean and low-nitrogen emissions by controlling the exhaust gas treatment mode with different NOx contents, and the waste heat utilization module realizes the overall energy efficiency improvement of the ammonia internal combustion engine system by controlling three-stage high-efficiency heat exchange.

[0070] The energy balance equation of the waste heat utilization module includes three parts: an ammonia preheater, an ammonia reheater, and an ammonia three-stage heater; among them, the energy balance equation of the ammonia preheater is:

[0071] q0*c0(T 02 -T 01 )+q0*Q0+q0*c2(T 002 -T 02 )=q1*c1*η1*(T 11 -T 12 )

[0072] In the formula, q0 is the inlet liquid ammonia mass flow rate of the ammonia preheater, c0 is the inlet liquid ammonia specific heat of the ammonia preheater, T 01 is the inlet liquid ammonia temperature of the ammonia preheater, T 02 is the liquid ammonia vaporization temperature, Q0 is the liquid ammonia vaporization latent heat, c2 is the specific heat of gaseous ammonia, T 002 is the outlet ammonia gas temperature of the ammonia preheater, q1 is the inlet jacket water mass flow rate of the ammonia preheater, c1 is the inlet jacket water specific heat of the ammonia preheater, η 1 is the heat exchange efficiency between liquid ammonia and jacket water of the ammonia preheater, T 11 is the inlet jacket water temperature of the ammonia preheater, T 12 is the jacket water return temperature of the ammonia preheater.

[0073] The energy balance equation of the ammonia reheater is:

[0074] q0*c2*(T 22 -T 21 )=η2*(q3*(c3*(T 31 -100)+c4*(100-T 32 ))+c1*q 33 *(100-T 32 )+q 33 *Q1)

[0075] c3=c 31 *M 31 +c 32 *M 32 +c 33 *M 33 +c 34*M 34 +c 35 *M 35

[0076] c4 = c 31 *M 31 +c 32 *M 32 +c 33 *M 33 +c 34 *M 34 +c 35 *M 36

[0077] where T 22 is the outlet ammonia gas temperature of the ammonia reheater, T 21 is the inlet ammonia gas temperature of the ammonia reheater, η2 is the heat transfer efficiency between the ammonia gas and the high-temperature tail gas in the ammonia reheater, q3 is the mass flow rate of the inlet tail gas of the ammonia reheater, c3 is the comprehensive specific heat of the inlet tail gas, T 31 is the inlet tail gas temperature of the ammonia reheater, c4 is the comprehensive specific heat of the outlet tail gas, T 32 is the outlet tail gas temperature of the ammonia reheater, q 33 is the mass rate of water vapor condensation in the tail gas, Q1 is the latent heat of vaporization of water, c 31 is the specific heat of nitrogen, M 31 is the mass content of nitrogen in the tail gas, c 32 is the specific heat of nitric oxide, M 32 is the mass content of nitric oxide in the tail gas, c 33 is the specific heat of nitrogen dioxide, M 33 is the mass content of nitrogen dioxide in the tail gas, c 34 is the specific heat of oxygen, M 34 is the mass content of oxygen in the tail gas, c 35 is the specific heat of water vapor, M 35 is the mass content of water vapor in the inlet tail gas, M 36 is the mass content of water vapor in the outlet tail gas.

[0078] The energy balance equation of the ammonia three-stage heater is:

[0079] q4 * c2 * (T 42 - T 41 ) = q5 * η4 * (c 31 * M 51 + c 32 * M 52 + c 33 * M 53 + c 34 * M 54 + c 35 * M 55 ) * (T51 -T 52 )

[0080] In the formula, q4 is the mass flow rate of ammonia at the inlet of the ammonia tertiary heater, T 42 is the ammonia temperature at the outlet of the ammonia tertiary heater, T 41 is the ammonia temperature at the inlet of the ammonia tertiary heater, q5 is the mass flow rate of the original tail gas at the inlet of the ammonia tertiary heater, η4 is the heat exchange efficiency of ammonia and high-temperature original tail gas in the ammonia tertiary heater, M 51 is the mass content of nitrogen in the original tail gas, M 52 is the mass content of nitric oxide in the original tail gas, M 53 is the mass content of nitrogen dioxide in the original tail gas, M 54 is the mass content of oxygen in the original tail gas, M 55 is the mass content of water vapor in the original tail gas, T 51 is the tail gas temperature at the inlet of the ammonia tertiary heater, T 52 is the tail gas temperature at the outlet of the ammonia tertiary heater.

[0081] As Figure 2 shown, the combustion power generation module performs the following steps:

[0082] Step 11, determine whether the ammonia internal combustion engine system needs pure ammonia combustion, pure hydrogen combustion or ammonia-hydrogen mixed combustion. If the ammonia internal combustion engine system needs pure ammonia combustion, then execute Step 12. If the ammonia internal combustion engine system needs pure hydrogen combustion, then execute Step 13. If the ammonia internal combustion engine system needs ammonia-hydrogen mixed combustion, then execute Step 14;

[0083] Step 12, the liquid ammonia in the liquid ammonia tank enters the ammonia preheater and ammonia reheater for heating. All the heated ammonia gas is sent to the internal combustion engine power generation system for combustion power generation through the ammonia direct delivery valve and mixed with air. The air and ammonia gas flow rates are appropriately adjusted through the air throttle valve and ammonia direct current valve. The volume flow rate ratio of air to ammonia gas is 6.5 - 7.5:1. At this time, the ammonia preheater inlet valve, ammonia reheater inlet valve, ammonia direct delivery valve, air throttle valve and intake pressure regulating valve are in the open state, and the ammonia tertiary heating inlet valve, mixed gas delivery valve, mixed gas purification valve, hydrogen delivery valve and ammonia reheater inlet valve are in the closed state;

[0084] Step 13: The liquid ammonia in the liquid ammonia tank enters the ammonia preheater and ammonia reheater for heating. All the heated ammonia gas enters the ammonia three-stage heater for three times of heating, and then is sent to the ammonia cracker to be decomposed into a hydrogen-ammonia-nitrogen mixture gas. The mixture gas all passes through the hydrogen purifier for purification and is stored in the hydrogen buffer tank. The hydrogen gas in the hydrogen buffer tank is mixed with air through the hydrogen delivery valve and sent to the internal combustion engine power generation system for combustion power generation. The air and hydrogen gas flow rates are appropriately adjusted through the throttle valve and the hydrogen delivery valve. The volume flow rate ratio of air to hydrogen gas is 9.5 - 10.5:1. At this time, the ammonia preheater inlet valve, ammonia reheater inlet valve, ammonia three-stage heating inlet valve, mixture gas purification valve, hydrogen delivery valve, air throttle valve and intake pressure regulating valve are in the open state, and the ammonia direct delivery valve and the mixture gas delivery valve are in the closed state;

[0085] Step 4: The liquid ammonia in the liquid ammonia tank enters the ammonia preheater and ammonia reheater for heating. All the heated ammonia gas enters the ammonia three-stage heater for three times of heating, and then is sent to the ammonia cracker to be decomposed into a hydrogen-ammonia-nitrogen mixture gas. The mixture gas all passes through the mixture gas delivery valve and is sent to the internal combustion engine power generation system. The hydrogen-ammonia ratio in the mixture gas is changed through the ammonia decomposition hydrogen production catalyst and the cracking temperature. The air and mixture gas flow rates are appropriately adjusted through the throttle valve and the mixture gas delivery valve. At this time, the ammonia preheater inlet valve, ammonia reheater inlet valve, ammonia three-stage heating inlet valve, mixture gas delivery valve, air throttle valve and intake pressure regulating valve are in the open state, and the ammonia direct delivery valve, mixture gas purification valve and hydrogen delivery valve are in the closed state.

[0086] As Figure 3 shown, the tail gas treatment module performs the following steps:

[0087] Step 21: Monitor whether the NOx content of the original exhaust gas of the engine detected by the front NOx sensor meets the emission requirements. If the NOx content of the original exhaust gas is too high, perform Step 22; otherwise, perform Step 24;

[0088] Step 22: Open the ammonia injection inlet valve to allow the liquid ammonia to enter the injection cabinet. Control the liquid ammonia flow rate sprayed into the SCR processor by the injection cabinet to increase. Keep the denitrification temperature within the range of 200 - 300 °C through the electric heating temperature control of the SCR processor, and monitor whether the NOx content of the treated tail gas meets the emission requirements through the rear NOx sensor. If it is too high, perform Step 23; otherwise, perform Step 24;

[0089] Step 23: Close the tail gas emission outlet valve, open the tail gas secondary treatment inlet valve, so that the treated tail gas re-enters the SCR processor for secondary tail gas treatment, and repeat Step 22;

[0090] Step 24: Close the tail gas secondary treatment inlet valve, open the tail gas emission outlet valve. The treated tail gas enters the ammonia reheater, and after heat exchange with ammonia gas in the ammonia reheater to reduce the temperature, it is discharged to the atmosphere.

[0091] As shown Figure 4 below, the waste heat utilization module performs the following steps:

[0092] Step 31: Monitor whether the return water temperature of the cylinder jacket water is higher than 85°C through the cylinder jacket water return temperature sensor. If it is on the high side, execute Step 32; otherwise, execute Step 33;

[0093] Step 32: Combine the energy balance equation of the ammonia preheater, increase the ammonia flow rate into the ammonia preheater by increasing the opening degree of the ammonia preheater inlet valve, and reduce the cylinder jacket water flow rate into the ammonia preheater by reducing the opening degree of the cylinder jacket water heat exchange inlet valve, so as to accelerate the cooling of the cylinder jacket water;

[0094] Step 33: Monitor whether the original exhaust gas of the engine is higher than 300°C through the front temperature sensor. If it is on the high side, execute Step 34; otherwise, execute Step 35;

[0095] Step 34: Combine the energy balance equation of the ammonia three-stage heater, increase the ammonia flow rate into the ammonia three-stage heater by increasing the opening degree of the ammonia three-stage heater inlet valve and reducing the opening degree of the ammonia direct supply valve, and reduce the exhaust gas flow rate into the ammonia three-stage heater by reducing the original exhaust gas outlet valve, so as to accelerate the cooling of the high-temperature original exhaust gas;

[0096] Step 35: Monitor whether the treated exhaust gas temperature is higher than 100°C through the rear temperature sensor. If it is on the high side, execute Step 36; otherwise, execute Step 37;

[0097] Step 36: Combine the energy balance equation of the ammonia reheater, increase the liquid ammonia flow rate by increasing the power of the liquid ammonia transfer pump and the opening degree of the ammonia reheater inlet valve, and reduce the exhaust gas flow rate by reducing the opening degree of the exhaust gas discharge outlet valve, so as to accelerate the cooling of the treated exhaust gas;

[0098] Step 37: The liquid ammonia transfer pump maintains the existing power, and the ammonia reheater inlet valve and the exhaust gas discharge outlet valve maintain the existing opening degrees.

[0099] The present invention uses green ammonia produced from new energy to replace the use of fossil fuels, and uses green ammonia to replace fossil fuels such as coal, gasoline, and diesel to achieve stable energy supply and reduce carbon emissions; at the same time, through a unique ammonia internal combustion engine system design and novel control methods, it effectively adapts to various operating modes of the internal combustion engine system and multi-stage utilization of waste heat, realizing clean, safe, and efficient power generation.

[0100] As described above, it is only a preferred embodiment of the present invention and does not impose any limitations on the present invention. Any simple modifications, changes, and equivalent structural changes made to the above embodiments according to the technical essence of the present invention still fall within the protection scope of the technical solution of the present invention.

Claims

1. An ammonia internal combustion engine system coupling exhaust gas treatment and waste heat utilization, characterized in that, It includes a fuel supply system, an air supply system, a waste heat utilization system, an exhaust gas treatment system and an internal combustion engine power generation system; The fuel supply system includes a liquid ammonia tank, a liquid ammonia transfer pump, an ammonia direct supply valve, an ammonia cracker, a mixed gas transfer valve, a mixed gas purification valve, a hydrogen purifier, a hydrogen buffer tank and a hydrogen transfer valve; The liquid ammonia in the liquid ammonia tank is sent out by the liquid ammonia transfer pump, forms ammonia gas after primary preheating vaporization and secondary reheating. Part of the ammonia gas is mixed with air through the ammonia direct supply valve and sent into the internal combustion engine power generation system for combustion power generation. Another part of the ammonia gas is sent into the ammonia cracker for decomposition to form a hydrogen-ammonia-nitrogen mixed gas after three times of heating. Part of the hydrogen-ammonia-nitrogen mixed gas is mixed with air through the mixed gas transfer valve and sent into the internal combustion engine power generation system. Another part of the hydrogen-ammonia-nitrogen mixed gas enters the hydrogen purifier through the mixed gas purification valve, obtains pure hydrogen and stores it in the hydrogen buffer tank, and hydrogen is transported to the internal combustion engine power generation system through the hydrogen transfer valve as needed; The air supply system includes an air filter, an air throttle valve and an air throttle valve position sensor; The outside air passes through the air filter to remove impurity particles in the air. The clean air then enters the air throttle valve and the flow rate is monitored and controlled in real time by the air throttle valve position sensor. The air flowing out of the air throttle valve is sent into the internal combustion engine power generation system; The waste heat utilization system includes an ammonia preheater, an ammonia preheater inlet valve, a jacket water heat exchange inlet valve, an ammonia reheater, an ammonia reheater inlet valve, an ammonia tertiary heater and an ammonia tertiary heating inlet valve; The liquid ammonia transported by the liquid ammonia transfer pump enters the ammonia preheater through the ammonia preheater inlet valve, exchanges heat with the jacket water coming out of the jacket water heat exchange inlet valve to vaporize. At the same time, the vaporized ammonia gas enters the ammonia reheater through the ammonia reheater inlet valve to conduct secondary heat exchange with the treated exhaust gas. The heated ammonia gas enters the ammonia tertiary heater through the ammonia tertiary heating inlet valve for three times of heating, and the heated ammonia gas enters the ammonia cracker for decomposition; The exhaust gas treatment system includes an original exhaust gas outlet valve, an SCR processor, an injection cabinet, a spray gun and an ammonia injection inlet valve; The liquid ammonia from the liquid ammonia tank enters the injection cabinet through the ammonia injection inlet valve. The injection cabinet controls the ammonia flow rate and sprays it into the SCR processor through the spray gun. The exhaust gas from the internal combustion engine power generation system enters the ammonia tertiary heater through the original exhaust gas outlet valve to heat the ammonia gas, and then undergoes denitrification treatment through the SCR processor; The internal combustion engine power generation system includes an engine, a generator, a nozzle, an ignition coil, a distributor, a spark plug, a storage battery, a rectifier and an intake pressure regulating valve; The air coming out of the air supply system and the hydrogen-ammonia-nitrogen mixed gas coming out of the fuel supply system are mixed and enter the engine through the intake pressure regulating valve and the nozzle, and are ignited by the ignition coil, the distributor and the spark plug for combustion, converting chemical energy into mechanical energy, and generating electricity through the generator. Most of the generated electricity is connected to the grid, and a small part of the electricity is converted through the rectifier and enters the storage battery for electricity storage, and the storage battery supplies power to the electrical equipment.

2. The ammonia internal combustion engine system for coupling exhaust gas treatment and waste heat utilization according to claim 1, wherein The waste heat utilization system further includes a jacket water return temperature sensor and a tail gas temperature sensor after heat exchange. The jacket water return temperature sensor and the tail gas temperature sensor after heat exchange are respectively used to monitor the jacket water temperature and the tail gas temperature after heat exchange.

3. The ammonia internal combustion engine system coupling tail gas treatment and waste heat utilization according to claim 1, characterized in that, The tail gas treatment system further includes a tail gas discharge outlet valve, a tail gas secondary treatment inlet valve, a front temperature sensor, a front NOx sensor, a rear NOx sensor and a muffler. The front temperature sensor is used to monitor the inlet tail gas temperature of the SCR processor. The front NOx sensor and the rear NOx sensor are used to monitor the NOx content of the inlet and outlet tail gas of the SCR processor. If the NOx content of the outlet tail gas after primary treatment is too high, it will re-enter the SCR processor through the tail gas secondary treatment inlet valve for tail gas treatment. If the NOx content requirement of the outlet tail gas is met, the tail gas will be heat-exchanged and cooled with the liquid ammonia in the ammonia reheater through the tail gas discharge outlet valve, and then discharged to the atmosphere through the muffler.

4. A ammonia internal combustion engine system coupling exhaust gas treatment and waste heat utilization according to claim 1, characterized in that, The ammonia cracker of the fuel supply system is electrically heated and temperature-controlled, using a low-temperature Ni-Ru-based ammonia decomposition hydrogen production catalyst, and cracking is carried out at normal pressure and a temperature of 200-500 °C according to the hydrogen-ammonia fuel supply demand, and is powered by the storage battery of the internal combustion engine power generation system.

5. The ammonia internal combustion engine system for coupling exhaust gas treatment and waste heat utilization according to claim 1, wherein The SCR processor of the tail gas treatment system is electrically heated and temperature-controlled, using platinum and palladium catalysts, and selective catalytic reduction denitrification is carried out in the temperature range of 200-300 °C according to the tail gas treatment demand, and is powered by the storage battery of the internal combustion engine power generation system.

6. The control method of the ammonia internal combustion engine system according to any one of claims 1-5, characterized in that, Control is carried out using a combustion power generation module, a tail gas treatment module and a waste heat utilization module; the combustion power generation module realizes the safe and efficient combustion of different fuels by controlling the operation mode of the ammonia internal combustion engine system. The tail gas treatment module realizes clean and low-nitrogen emissions by controlling the tail gas treatment modes with different NOx contents. The waste heat utilization module realizes the overall energy efficiency improvement of the ammonia internal combustion engine system by controlling three-stage high-efficiency heat exchange.

7. The control method according to claim 6, wherein The energy balance equation of the waste heat utilization module includes three parts: an ammonia preheater, an ammonia reheater and an ammonia three-stage heater; among them, the energy balance equation of the ammonia preheater is: q0*c0(T 02 -T 01 )+q0*Q0+q0*c2(T 002 -T 02 )=q1*c1*η1*(T 11 -T 12 ) Wherein, q0 is the mass flow rate of liquid ammonia at the inlet of the ammonia preheater, c0 is the specific heat of liquid ammonia at the inlet of the ammonia preheater, T 01 is the temperature of liquid ammonia at the inlet of the ammonia preheater, T 02 is the vaporization temperature of liquid ammonia, Q0 is the latent heat of vaporization of liquid ammonia, c2 is the specific heat of gaseous ammonia, T 002 is the temperature of ammonia gas at the outlet of the ammonia preheater, q1 is the mass flow rate of jacket water at the inlet of the ammonia preheater, c1 is the specific heat of jacket water at the inlet of the ammonia preheater, η1 is the heat exchange efficiency between liquid ammonia and jacket water in the ammonia preheater, T 11 is the temperature of jacket water at the inlet of the ammonia preheater, T 12 is the return water temperature of the jacket water of the ammonia preheater; The energy balance equation of the ammonia reheater is: q0*c2*(T 22 -T 21 ) = η2*(q3*(c3*(T 31 -100)+c4*(100-T 32 ))+c1*q 33 *(100-T 32 )+q 33 *Q1) c3 = c 31 *M 31 +c 32 *M 32 +c 33 *M 33 +c 34 *M 34 +c 35 *M 35 c4 = c 31 *M 31 +c 32 *M 32 +c 33 *M 33 +c 34 *M 34 +c 35 *M 36 Where, T 22 is the outlet ammonia gas temperature of the ammonia reheater, T 21 is the inlet ammonia gas temperature of the ammonia reheater, η2 is the heat exchange efficiency between the ammonia gas and the high-temperature tail gas in the ammonia reheater, q3 is the mass flow rate of the inlet tail gas of the ammonia reheater, c3 is the comprehensive specific heat of the inlet tail gas, T 31 is the inlet tail gas temperature of the ammonia reheater, c4 is the comprehensive specific heat of the outlet tail gas, T 32 is the outlet tail gas temperature of the ammonia reheater, q 33 is the mass rate of water vapor condensation in the tail gas, Q1 is the latent heat of vaporization of water, c 31 is the specific heat of nitrogen, M 31 is the mass content of nitrogen in the tail gas, c 32 is the specific heat of nitric oxide, M 32 is the mass content of nitric oxide in the tail gas, c 33 is the specific heat of nitrogen dioxide, M 33 is the mass content of nitrogen dioxide in the tail gas, c 34 is the specific heat of oxygen, M 34 is the mass content of oxygen in the tail gas, c 35 is the specific heat of water vapor, M 35 is the mass content of water vapor in the inlet tail gas, M 36 is the mass content of water vapor in the outlet tail gas; The energy balance equation of the ammonia three-stage heater is q4*c2*(T 42 -T 41 )=q5*η4*(c 31 *M 51 +c 32 *M 52 +c 33 *M 53 +c 34 *M 54 +c 35 *M 55 )*(T 51 -T 52 ) Wherein, q4 is the mass flow rate of ammonia at the inlet of the ammonia tertiary heater, T 42 is the ammonia temperature at the outlet of the ammonia tertiary heater, T 41 is the ammonia temperature at the inlet of the ammonia tertiary heater, q5 is the mass flow rate of the original tail gas at the inlet of the ammonia tertiary heater, η4 is the heat exchange efficiency of ammonia and the high-temperature original tail gas in the ammonia tertiary heater, M 51 is the mass content of nitrogen in the original tail gas, M 52 is the mass content of nitric oxide in the original tail gas, M 53 is the mass content of nitrogen dioxide in the original tail gas, M 54 is the mass content of oxygen in the original tail gas, M 55 is the mass content of water vapor in the original tail gas, T 51 is the tail gas temperature at the inlet of the ammonia tertiary heater, T 52 is the tail gas temperature at the outlet of the ammonia tertiary heater.

8. The control method according to claim 6, wherein The combustion power generation module executes the following steps: Step 11, determine whether the ammonia internal combustion engine system needs pure ammonia combustion, pure hydrogen combustion or ammonia-hydrogen mixed combustion. If the ammonia internal combustion engine system needs pure ammonia combustion, execute step 12. If the ammonia internal combustion engine system needs pure hydrogen combustion, execute step 13. If the ammonia internal combustion engine system needs ammonia-hydrogen mixed combustion, execute step 14; Step 12, the liquid ammonia in the liquid ammonia tank enters the ammonia preheater and the ammonia reheater for heating. All the ammonia gas coming out of the heating enters the internal combustion engine power generation system through the ammonia gas direct delivery valve and is mixed with air for combustion power generation. The air and ammonia gas flow rates are appropriately adjusted through the air throttle valve and the ammonia gas direct current valve. The volume flow ratio of air to ammonia gas is 6.5-7.5:

1. At this time, the ammonia preheater inlet valve, the ammonia reheater inlet valve, the ammonia gas direct delivery valve, the air throttle valve and the intake pressure regulating valve are in the open state, and the ammonia three-stage heating inlet valve, the mixed gas delivery valve, the mixed gas purification valve, the hydrogen delivery valve and the ammonia reheater inlet valve are in the closed state; Step 13, the liquid ammonia in the liquid ammonia tank enters the ammonia preheater and ammonia reheater for heating. All the heated ammonia gas enters the ammonia triple heater for three - stage heating, and then is sent to the ammonia cracker to be decomposed into a hydrogen - ammonia - nitrogen mixture. The mixture all passes through the hydrogen purifier for purification and is stored in the hydrogen buffer tank. The hydrogen in the hydrogen buffer tank is mixed with air through the hydrogen delivery valve and sent to the internal combustion engine power generation system for combustion power generation. The air and hydrogen flow rates are appropriately adjusted through the throttle valve and hydrogen delivery valve. The volume flow ratio of air to hydrogen is 9.5 - 10.5:

1. At this time, the ammonia preheater inlet valve, ammonia reheater inlet valve, ammonia triple - heating inlet valve, mixture purification valve, hydrogen delivery valve, air throttle valve, and intake pressure regulating valve are in the open state, and the ammonia direct - delivery valve and mixture delivery valve are in the closed state; Step 4, the liquid ammonia in the liquid ammonia tank enters the ammonia preheater and ammonia reheater for heating. All the heated ammonia gas enters the ammonia triple heater for three - stage heating, and then is sent to the ammonia cracker to be decomposed into a hydrogen - ammonia - nitrogen mixture. The mixture all passes through the mixture delivery valve and is sent to the internal combustion engine power generation system. The hydrogen - ammonia ratio in the mixture is changed by the ammonia decomposition hydrogen - production catalyst and cracking temperature. The air and mixture flow rates are appropriately adjusted through the throttle valve and mixture delivery valve. At this time, the ammonia preheater inlet valve, ammonia reheater inlet valve, ammonia triple - heating inlet valve, mixture delivery valve, air throttle valve, and intake pressure regulating valve are in the open state, and the ammonia direct - delivery valve, mixture purification valve, and hydrogen delivery valve are in the closed state.

9. The control method according to claim 6, characterized in that The tail - gas treatment module performs the following steps: Step 21, monitor whether the NOx content of the original exhaust gas of the engine detected by the front NOx sensor meets the emission requirements. If the NOx content of the original exhaust gas is high, then execute Step 22; otherwise, execute Step 24; Step 22, open the ammonia injection inlet valve to make the liquid ammonia enter the injection cabinet. Control the injection cabinet to increase the liquid ammonia flow rate sprayed into the SCR processor by the spray gun. Use the electric heating temperature control of the SCR processor to maintain the denitrification temperature within the range of 200 - 300 °C, and monitor whether the NOx content of the treated exhaust gas detected by the rear NOx sensor meets the emission requirements. If it is high, then execute Step 23; otherwise, execute Step 24; Step 23, close the tail - gas emission outlet valve, open the tail - gas secondary - treatment inlet valve, so that the treated exhaust gas re - enters the SCR processor for secondary tail - gas treatment, and repeat Step 22; Step 24, close the tail - gas secondary - treatment inlet valve, open the tail - gas emission outlet valve. The treated exhaust gas enters the ammonia reheater, exchanges heat with ammonia gas in the ammonia reheater to cool down, and then is discharged to the atmosphere.

10. The control method according to claim 6, characterized in that, The waste - heat utilization module performs the following steps: Step 31, monitor whether the temperature of the cylinder - jacket water return detected by the cylinder - jacket water return temperature sensor is higher than 85 °C. If it is high, then execute Step 32; otherwise, execute Step 33; Step 32, combined with the energy - balance equation of the ammonia preheater, increase the ammonia gas flow rate entering the ammonia preheater by increasing the opening degree of the ammonia preheater inlet valve, and reduce the cylinder - jacket water flow rate entering the ammonia preheater by reducing the opening degree of the cylinder - jacket water heat - exchange inlet valve, so as to accelerate the cooling of the cylinder - jacket water; Step 33: Monitor whether the original exhaust gas of the engine is higher than 300 °C through the front temperature sensor. If it is on the high side, execute Step 34; otherwise, execute Step 35. Step 34: Combine the energy balance equation of the ammonia tertiary heater. Increase the ammonia flow rate into the ammonia tertiary heater by increasing the opening of the ammonia tertiary heater inlet valve and decreasing the opening of the ammonia direct supply valve. Reduce the exhaust gas flow rate into the ammonia tertiary heater by decreasing the original exhaust gas outlet valve, so as to accelerate the cooling of the high-temperature original exhaust gas. Step 35: Monitor whether the exhaust temperature of the treated exhaust gas is higher than 100 °C through the rear temperature sensor. If it is on the high side, execute Step 36; otherwise, execute Step 37. Step 36: Combine the energy balance equation of the ammonia reheater. Increase the liquid ammonia flow rate by increasing the power of the liquid ammonia transfer pump and the opening of the ammonia reheater inlet valve. Reduce the exhaust gas flow rate by decreasing the opening of the exhaust gas discharge outlet valve, so as to accelerate the cooling of the treated exhaust gas. Step 37: The liquid ammonia transfer pump maintains the existing power, and the ammonia reheater inlet valve and the exhaust gas discharge outlet valve maintain the existing opening.

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