A regenerative and reactive internal combustion engine waste heat ammonia hydrogen production system and control method

Abstract

The present invention discloses a regenerative re-reactive internal combustion engine waste heat ammonia hydrogen production system and a control method, which relates to the technical fields of production, conversion, storage and utilization of clean zero-carbon fuels. The main components of the system include an internal combustion engine, a cooling water tank, a liquid ammonia tank, a gasification chamber, a regenerator, a heater, an ammonia reactor, a temperature sensor, an ammonia sensor, a fuel supply system and various control valves. In addition to utilizing the waste heat of the internal combustion engine, this system also recovers the waste heat of the ammonia-hydrogen mixture after the reaction, improves the intake efficiency, and has a higher energy utilization efficiency. At the same time, the ammonia hydrogen production system proposed by the present invention can realize multiple reactions of the ammonia-hydrogen mixture. With the corresponding control strategy, it can effectively control the degree of ammonia decomposition, flexibly adjust the ammonia-hydrogen ratio and the total flow rate of the internal combustion engine intake air, and solve the problems of low ammonia decomposition efficiency and poor response to the internal combustion engine working conditions in the existing system.

Description

Technical Field

[0001] The present invention relates to the technical fields of production, conversion, storage and utilization of clean zero-carbon fuels, and particularly relates to a heat regenerative and re-reactive internal combustion engine waste heat ammonia hydrogen production system and a control method thereof. Background Art

[0002] Ammonia and hydrogen contain rich chemical energy, can generate a large amount of heat when reacting with oxygen, and do not produce greenhouse gases such as carbon dioxide when burning. They have the advantages of "zero-carbon and low-emission". Therefore, fuels such as ammonia and hydrogen are a class of highly potential alternative fuels. In addition to the above advantages, hydrogen has a high energy density, active chemical properties, and the product is only water, making it an ideal future energy source. However, the high production cost of hydrogen, its flammability and explosiveness, and difficulty in liquefaction make its storage and transportation very difficult, becoming the main obstacle restricting the large-scale development of hydrogen energy. Compared with hydrogen, ammonia has stable chemical properties and can be liquefied at 0.8 MPa at room temperature, which is convenient for storage and transportation. Therefore, ammonia can not only be used as a fuel, but also be a very important hydrogen carrier.

[0003] In power devices such as internal combustion engines, the use of ammonia-hydrogen fuels has been extensively studied. The current common fuel transportation method is to load a liquid ammonia tank on an internal combustion engine. The liquid ammonia is vaporized and then undergoes a decomposition reaction under normal pressure and at a temperature above about 400 °C to release hydrogen. The generated hydrogen is mixed with ammonia after being adjusted and then enters the internal combustion engine to burn and do work, realizing the conversion of chemical energy into mechanical energy. The vaporization of liquid ammonia and ammonia decomposition to produce hydrogen require a large amount of heat. The current heating methods used more are to recover the waste heat of the internal combustion engine in combination with electric heating or additional fuel heating, but the additional fuel or electric heating reduces the overall energy efficiency of the internal combustion engine. In addition, when the operating conditions of the internal combustion engine change, the amount of waste heat is unstable, which may lead to incomplete decomposition of ammonia in the ammonia reactor, resulting in too little hydrogen production. At this time, the demand for hydrogen-ammonia fuels by the internal combustion engine may also change. Therefore, the internal combustion engine may have problems such as insufficient fuel supply and difficult combustion control under variable operating conditions. Finally, the high-temperature ammonia-hydrogen mixed gas after the reaction needs to be cooled and heat released before it can enter the combustion chamber to burn to ensure normal intake efficiency. The existing ammonia hydrogen production system has not effectively recovered this part of the heat. Therefore, there is an urgent need for an ammonia hydrogen production system in the power device to efficiently recover and utilize waste heat, control the reaction degree of ammonia hydrogen production, and ensure the efficient operation of the power device. Summary of the Invention

[0004] To meet the heat demand during the ammonia decomposition process and solve the problem of incomplete ammonia decomposition reaction, the present invention provides a heat regenerative and re-reactive internal combustion engine waste heat ammonia hydrogen production system and a control method thereof.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] The present invention provides a waste heat ammonia hydrogen production system for a regenerative re-reaction internal combustion engine, which includes a liquid ammonia tank, a gasification chamber, a cooling water tank, an internal combustion engine, a second flow control valve, a third flow control valve, a fuel supply system, a regenerator, and an ammonia reactor; the outlet of the liquid ammonia tank is communicated with the fuel inlet of the gasification chamber, and the fuel outlet of the gasification chamber is communicated with the inlets of the second flow control valve and the third flow control valve; the cooling water tank is used to cool the internal combustion engine, the cooling water outlet of the gasification chamber is communicated with the inlet of the cooling water tank, the outlet of the cooling water tank is communicated with the cooling water inlet of the internal combustion engine, and the cooling water outlet of the internal combustion engine is communicated with the cooling water inlet of the gasification chamber; the outlet end of the third flow control valve is communicated with the inlet end of the fuel supply system, and the outlet end of the fuel supply system is communicated with the internal combustion engine; the outlet end of the second flow control valve is communicated with the first inlet of the regenerator, the first outlet of the regenerator is communicated with the first inlet of the regenerator, the first outlet of the regenerator is communicated with the inlet of the ammonia reactor, the outlet of the ammonia reactor is communicated with the second inlet of the regenerator, the second outlet of the regenerator is communicated with the second inlet of the regenerator, and the second outlet of the regenerator is communicated with the inlet end of the fuel supply system; the ammonia reactor is arranged in the exhaust pipe of the internal combustion engine.

[0007] Optionally, a heater is further arranged between the ammonia reactor and the regenerator, and the heater is arranged in the exhaust pipe of the internal combustion engine.

[0008] Optionally, the ammonia reactor is located upstream of the exhaust pipe of the internal combustion engine, and the heater is located downstream of the exhaust pipe of the internal combustion engine.

[0009] Optionally, the heater adopts a finned heat exchanger.

[0010] Optionally, a temperature sensor, an ammonia sensor, and a first three-way valve are sequentially arranged between the outlet of the ammonia reactor and the second inlet of the regenerator; a second three-way valve is arranged between the third interface of the first three-way valve and the inlet of the ammonia reactor, and a third three-way valve is arranged between the first outlet of the regenerator and the heater; the third interface of the second three-way valve is communicated with the third interface of the third three-way valve.

[0011] Optionally, the second flow control valve, the third flow control valve, the heater, the temperature sensor, the ammonia sensor, the first three-way valve, the second three-way valve, and the third three-way valve are all electrically connected to a control module.

[0012] Optionally, a first flow control valve is arranged between the liquid ammonia tank and the gasification chamber, and the first flow control valve is electrically connected to the control module.

[0013] Optionally, the regenerator adopts a plate heat exchanger.

[0014] The present invention also discloses a control method for an internal combustion engine waste heat ammonia hydrogen production system based on the above regenerative re-reaction type, including the following working conditions.

[0015] Stable fuel supply state: Stable operation is the main working condition of the internal combustion engine. Under this condition, the demand for fuel by the internal combustion engine is stable; when the fuel is stably supplied, ammonia flows out of the liquid ammonia tank under the control of the first flow control valve, flows through the gasification chamber, and is divided under the control of the second flow control valve and the second flow control valve. Part of it directly flows into the fuel supply system and is mixed with the ammonia-hydrogen mixture and then participates in combustion. Part of it flows through the regenerator, the third three-way valve, the heater and the ammonia reactor to decompose and produce hydrogen; the temperature sensor and ammonia sensor at the outlet of the ammonia reactor detect the temperature and ammonia concentration of the ammonia-hydrogen mixture. If the ammonia concentration in the mixture is low, it is considered that the degree of ammonia decomposition reaction reaches the ideal state, then the passage from the first three-way valve to the regenerator is fully opened, and the passage to the second three-way valve is closed, and all the ammonia-hydrogen mixture directly enters the fuel supply system and is mixed with ammonia and then completes combustion in the internal combustion engine; if the degree of ammonia decomposition reaction does not reach the ideal state, analyze the data of the temperature sensor. If the temperature of the temperature sensor is low, the incomplete ammonia decomposition is mainly due to the low reaction temperature. In this case, the circuit from the first three-way valve to the second three-way valve is opened, the circuit from the second three-way valve to the ammonia reactor is closed, and the circuit to the first three-way valve is fully opened. Part of the ammonia-hydrogen mixture passes through the circuit of the second three-way valve and the third three-way valve and then remixes with fresh ammonia, and then passes through the heater and the ammonia reactor to realize reheating and re-reaction of the ammonia-hydrogen mixture. Continuously adjust the opening degree of the mixture of each three-way valve and the ratio of the re-reaction and reheating mixture until the hydrogen-ammonia ratio at the outlet of the ammonia reactor meets the requirements of the internal combustion engine; if the degree of ammonia decomposition does not reach the ideal state and the temperature of the ammonia-hydrogen mixture is high, the mixture does not need to be reheated, and part of the ammonia-hydrogen mixture directly flows into the ammonia reactor through the second three-way valve to realize re-reaction, and continuously adjust the ratio of the re-reaction mixture until the hydrogen-ammonia ratio at the outlet of the ammonia reactor meets the requirements of the internal combustion engine.

[0016] Increased fuel demand: During vehicle acceleration or uphill driving conditions, the power of the internal combustion engine increases, and the demand for ammonia-hydrogen fuel becomes larger. If the first three-way valve is in a state where the flow to the regenerator is fully open and the flow to the second three-way valve is fully closed at this time, the mixed gas does not undergo further reaction. After adjusting the first flow control valve, the second flow control valve, and the third flow control valve until the total flow meets the demand of the internal combustion engine, then judge the degree of ammonia decomposition reaction, and adjust each three-way valve until the hydrogen-ammonia ratio at the outlet of the ammonia reactor meets the demand of the internal combustion engine. The adjustment method is the same as the adjustment steps in the stable state. If the fuel demand increases during the re-reaction of the mixed gas, to match the change in the fuel demand side, the first three-way valve is adjusted in a timely manner to increase the flow output ratio to the regenerator. At the same time, the second three-way valve and the third three-way valve are adjusted in coordination to increase the flow to the ammonia reactor path. At the same time, the first flow control valve at the rear end of the liquid ammonia tank is quickly adjusted to increase the total flow, and the second three-way valve and the first flow control valve are adjusted to ensure that the ammonia gas flow in the ammonia hydrogen production system does not change significantly. After the total flow increases, judge the degree of ammonia decomposition reaction, and adjust each three-way valve to the stable state;

[0017] Decreased fuel demand: During vehicle deceleration or downhill driving conditions, the power of the internal combustion engine decreases, and the demand for ammonia-hydrogen fuel decreases. If the first three-way valve is in a state where the flow to the regenerator is fully open and the flow to the second three-way valve is fully closed at this time, the mixed gas does not undergo further reaction. After adjusting the first flow control valve, the second flow control valve, and the third flow control valve until the total flow meets the demand of the internal combustion engine, then judge the degree of ammonia decomposition reaction, and adjust each three-way valve until the hydrogen-ammonia ratio at the outlet of the ammonia reactor meets the demand of the internal combustion engine. The adjustment method is the same as the adjustment steps in the stable state. If the fuel demand decreases during the re-reaction of the mixed gas, to match the change in the fuel demand side, the first three-way valve is adjusted in a timely manner to reduce the flow output ratio to the regenerator. At the same time, the second three-way valve and the third three-way valve are adjusted to reduce the flow to the ammonia reactor path. At the same time, the first flow control valve at the rear end of the liquid ammonia tank is quickly adjusted to reduce the total flow, and the second three-way valve and the first flow control valve are adjusted to ensure that the ammonia gas flow in the ammonia hydrogen production system does not change significantly. After the total flow decreases, judge the degree of ammonia decomposition reaction, and adjust each three-way valve to the stable state.

[0018] The present invention has achieved the following technical effects compared with the prior art:

[0019] 1. A large amount of heat is required for ammonia vaporization and decomposition. The heating method proposed in the present invention not only utilizes the waste heat of the internal combustion engine flue gas and cooling water, but also recovers the heat of the high-temperature ammonia-hydrogen mixed gas, and the heat utilization efficiency is higher.

[0020] 2. The ammonia hydrogen production system proposed in the present invention can control the opening degree of the three-way valve, reasonably distribute the ammonia gas flow for reheating and re-reaction, and adjust the ammonia decomposition degree as needed. The ratio of ammonia gas and hydrogen gas in the mixed gas after the reaction can be freely adjusted, which is beneficial to realizing the efficient combustion of the fuel.

[0021] 3. Compared with the traditional control strategy of using a flow valve to control the total flow rate, the control strategy of the three-way valve for distributing the return flow proposed by the present invention has a faster response speed to the change in the fuel quantity demand of the internal combustion engine, can further achieve flexible control of the total fuel supply flow rate, and solve the problem of insufficient fuel supply of the internal combustion engine under variable working conditions.

[0022] 4. The ammonia hydrogen production system proposed by the present invention uses the design idea of replacing the ammonia hydrogen mixture cooler with a regenerator, reducing the complexity of the system, further reducing the temperature of the ammonia hydrogen mixture, decreasing the specific volume, having a higher intake efficiency of the internal combustion engine, and being beneficial to the improvement of the power of the internal combustion engine.

[0023] 5. The ammonia hydrogen production system designed by the present invention has no complex and precise components, is simple in equipment and high in reliability. The design of placing the ammonia reactor and the heater in the exhaust pipe of the internal combustion engine further reduces the overall volume of the system, which helps in large-scale applications on power equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required to be used in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0025] Figure 1 It is a schematic structural diagram of the internal combustion engine waste heat ammonia hydrogen production system with regenerative re-reaction of the present invention.

[0026] Description of the reference numerals: 1, liquid ammonia tank; 2, first flow control valve; 3, gasification chamber; 4, second flow control valve; 5, regenerator; 6, heater; 7, ammonia reactor; 8, temperature sensor; 9, ammonia sensor; 10, third flow control valve; 11, fuel supply system; 12, internal combustion engine; 101, internal combustion engine exhaust pipe; 201, cooling water tank; 301, first three-way valve; 302, second three-way valve; 303, third three-way valve. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0028] Embodiment 1:

[0029] As Figure 1As shown in the figure, this embodiment provides a heat regenerative and reactive internal combustion engine waste heat ammonia hydrogen production system, including a liquid ammonia tank 1, a gasification chamber 3, a cooling water tank 201, an internal combustion engine 12, a second flow control valve 4, a third flow control valve 10, a fuel supply system 11, a regenerator 5, and an ammonia reactor 7; the outlet of the liquid ammonia tank 1 is connected to the fuel inlet of the gasification chamber 3, and the fuel outlet of the gasification chamber 3 is connected to the inlets of the second flow control valve 4 and the third flow control valve 10; the cooling water tank 201 is used to cool the internal combustion engine 12, the cooling water outlet of the gasification chamber 3 is connected to the inlet of the cooling water tank 201, the outlet of the cooling water tank 201 is connected to the cooling water inlet of the internal combustion engine 12, and the cooling water outlet of the internal combustion engine 12 is connected to the cooling water inlet of the gasification chamber 3; the outlet end of the third flow control valve 10 is connected to the inlet end of the fuel supply system 11, and the outlet end of the fuel supply system 11 is connected to the internal combustion engine 12; the outlet end of the second flow control valve 4 is connected to the first inlet of the regenerator 5, the first outlet of the regenerator 5 is connected to the first inlet of the regenerator 5, the first outlet of the regenerator 5 is connected to the inlet of the ammonia reactor 7, the outlet of the ammonia reactor 7 is connected to the second inlet of the regenerator 5, the second outlet of the regenerator 5 is connected to the second inlet of the regenerator 5, and the second outlet of the regenerator 5 is connected to the inlet end of the fuel supply system 11; the ammonia reactor 7 is arranged in the internal combustion engine exhaust pipe 101.

[0030] In this specific embodiment, a heater 6 is further arranged between the ammonia reactor 7 and the regenerator 5, and the heater 6 is arranged in the internal combustion engine exhaust pipe 101. The ammonia reactor 7 is located upstream of the internal combustion engine exhaust pipe 101, and the heater 6 is located downstream of the internal combustion engine exhaust pipe 101.

[0031] In this specific embodiment, the heater 6 adopts a finned heat exchanger. The regenerator 5 adopts a plate heat exchanger.

[0032] A temperature sensor 8, an ammonia sensor 9, and a first three-way valve 301 are sequentially arranged between the outlet of the ammonia reactor 7 and the second inlet of the regenerator 5; a second three-way valve 302 is arranged between the third interface of the first three-way valve 301 and the inlet of the ammonia reactor 7, and a third three-way valve 303 is arranged between the first outlet of the regenerator 5 and the heater 6; the third interface of the second three-way valve 302 is connected to the third interface of the third three-way valve 303.

[0033] A first flow control valve 2 is arranged between the liquid ammonia tank 1 and the gasification chamber 3. The first flow control valve 2, the second flow control valve 4, the third flow control valve 10, the heater 6, the temperature sensor 8, the ammonia sensor 9, the first three-way valve 301, the second three-way valve 302, and the third three-way valve 303 are all electrically connected to the control module.

[0034] In this embodiment, the main working fluids in the waste heat ammonia hydrogen production system of the regenerative re-reactive internal combustion engine 12 include ammonia (ammonia-hydrogen mixture), high-temperature flue gas, and the cooling water of the internal combustion engine 12. Among them, ammonia is stored in a high-pressure (>0.8 MPA) liquid ammonia tank 1 in a liquid state. When the internal combustion engine 12 operates, the first flow control valve 2 at the outlet of the liquid ammonia tank 1 opens, and the liquid ammonia flows into the gasification chamber 3 to absorb the heat of the high-temperature cooling water and quickly evaporates into a gaseous state. The gasified ammonia is split under the control of the second flow control valve 4 and the third flow control valve 10. Part of it flows into the fuel supply system 11 and mixes with the ammonia-hydrogen mixture, and then directly participates in the combustion of the internal combustion engine 12; part of it flows into the regenerator 5 for preliminary heating, and then flows into the heater 6 through the third three-way valve 303 to exchange heat with the high-temperature flue gas, and the temperature is raised to more than 400 °C. Then, the high-temperature ammonia flows into the ammonia reactor 7. The flue gas temperature at the position of the ammonia reactor 7 is higher, and the temperature of the high-temperature ammonia can be further increased. At the same time, ammonia decomposes into nitrogen and hydrogen in the ammonia reactor 7 under the action of a catalyst. The main components of the ammonia-hydrogen mixture after the reaction include hydrogen, nitrogen, and unreacted ammonia. After the ammonia-hydrogen mixture flows out of the ammonia reactor 7, it flows through the temperature sensor 8 and the ammonia sensor 9, and then after passing through the first three-way valve 301, the ammonia-hydrogen mixture is split. Part of the ammonia-hydrogen mixture enters the second three-way valve 302 and then enters the ammonia reactor 7 again, or flows through the third three-way valve 303 and the heater 6 and then enters the ammonia reactor 7. Another part of the mixture of the first three-way valve 301 directly enters the regenerator 5 to cool and release heat, and finally is controlled by the fuel supply system 11 of the internal combustion engine 12, mixes with ammonia, and enters the internal combustion engine 12 to complete combustion. The high-temperature flue gas flows in the exhaust pipe and successively passes through the ammonia reactor 7 and the heater 6; the cooling water is stored in the cooling water tank 201, flows into the internal combustion engine 12 to absorb the waste heat of the internal combustion engine 12, then flows into the gasification chamber 3 to provide heat for ammonia gasification, and finally flows back to the cooling water tank 201.

[0035] Embodiment 2:

[0036] This embodiment provides a control method for the waste heat ammonia hydrogen production system of the regenerative re-reactive internal combustion engine based on that in Embodiment 1. Realizing the hourly change of fuel supply to meet the requirements of the internal combustion engine for fuel components and total fuel volume is the basic requirement of the ammonia hydrogen production and fuel supply system. The control of fuel by the ammonia on-line hydrogen production system proposed in this embodiment is mainly completed through the adjustment of the first three-way valve 301, the second three-way valve 302, and the third three-way valve 303, and specifically includes the following working conditions.

[0037] Stable fuel supply state: Stable operation is the main operating condition of the internal combustion engine 12. Under this condition, the fuel demand of the internal combustion engine 12 is stable; when the fuel is stably supplied, ammonia flows out from the liquid ammonia tank 1 under the control of the first flow control valve 2, passes through the gasification chamber 3, and is branched under the control of the second flow control valve 4 and the second flow control valve 4. Part of it directly flows into the fuel supply system 11 to be mixed with the ammonia-hydrogen mixture and then participates in combustion. Part of it passes through the regenerator 5, the third three-way valve 303, the heater 6 and the ammonia reactor 7 to decompose and generate hydrogen; the temperature sensor 8 and the ammonia sensor 9 at the outlet of the ammonia reactor 7 detect the temperature and ammonia concentration of the ammonia-hydrogen mixture. If the ammonia concentration in the mixture is low, it is considered that the degree of ammonia decomposition reaction reaches the ideal state. Then, the passage from the first three-way valve 301 to the regenerator 5 is fully opened, and the passage to the second three-way valve 302 is closed. All the ammonia-hydrogen mixture directly enters the fuel supply system 11 to be mixed with ammonia and then completes combustion in the internal combustion engine 12; if the degree of ammonia decomposition reaction does not reach the ideal state, analyze the data of the temperature sensor 8. If the temperature of the temperature sensor 8 is low, the incomplete ammonia decomposition is mainly due to the low reaction temperature. In this case, open the loop from the first three-way valve 301 to the second three-way valve 302, close the loop from the second three-way valve 302 to the ammonia reactor 7, and fully open the loop to the first three-way valve 301. Part of the ammonia-hydrogen mixture passes through the loop of the second three-way valve 302 and the third three-way valve 303, and then is remixed with fresh ammonia. After that, it passes through the heater 6 and the ammonia reactor 7 to realize reheating and re-reaction of the ammonia-hydrogen mixture. Continuously adjust the opening degree of the mixture of each three-way valve, and adjust the proportion of the re-reacted and reheated mixture until the hydrogen-ammonia ratio at the outlet of the ammonia reactor 7 meets the requirements of the internal combustion engine 12; if the degree of ammonia decomposition does not reach the ideal state and the temperature of the ammonia-hydrogen mixture is high, the mixture does not need to be reheated. Part of the ammonia-hydrogen mixture directly flows into the ammonia reactor 7 through the second three-way valve 302 to realize re-reaction. Continuously adjust the proportion of the re-reacted mixture until the hydrogen-ammonia ratio at the outlet of the ammonia reactor 7 meets the requirements of the internal combustion engine 12;

[0038] Increased fuel demand: When the vehicle is accelerating or climbing a slope, the power of the internal combustion engine 12 increases, and the demand for ammonia-hydrogen fuel becomes larger. If the first three-way valve 301 is in the state where the flow to the regenerator 5 is fully open and the flow to the second three-way valve 302 is fully closed at this time, at this time, the mixed gas does not undergo a re-reaction. After adjusting the first flow control valve 2, the second flow control valve 4, and the third flow control valve 10 so that the total flow meets the demand of the internal combustion engine 12 in the state, then judge the degree of ammonia decomposition reaction, and adjust each three-way valve until the hydrogen-ammonia ratio at the outlet of the ammonia reactor 7 meets the demand of the internal combustion engine 12. The adjustment method is the same as the adjustment steps in the stable state. If the fuel demand increases during the re-reaction of the mixed gas, in order to cooperate with the change of the fuel demand end, the first three-way valve 301 is adjusted in time to increase the flow output ratio to the regenerator 5. At the same time, the second three-way valve 302 and the third three-way valve 303 are adjusted in cooperation to increase the flow to the ammonia reactor 7 path. At the same time, the first flow control valve 2 at the rear end of the liquid ammonia tank 1 is quickly adjusted to increase the total flow, and the second three-way valve 302 and the first flow control valve 2 are adjusted to ensure that the ammonia gas flow in the ammonia hydrogen production system does not change significantly. After the total flow increases, judge the degree of ammonia decomposition reaction, and adjust each three-way valve to a stable state;

[0039] Decreased fuel demand: When the vehicle is decelerating or descending a slope, the power of the internal combustion engine 12 decreases, and the demand for ammonia-hydrogen fuel decreases. If the first three-way valve 301 is in the state where the flow to the regenerator 5 is fully open and the flow to the second three-way valve 302 is fully closed at this time, at this time, the mixed gas does not undergo a re-reaction. After adjusting the first flow control valve 2, the second flow control valve 4, and the third flow control valve 10 so that the total flow meets the demand of the internal combustion engine 12 in the state, then judge the degree of ammonia decomposition reaction, and adjust each three-way valve until the hydrogen-ammonia ratio at the outlet of the ammonia reactor 7 meets the demand of the internal combustion engine 12. The adjustment method is the same as the adjustment steps in the stable state. If the fuel demand decreases during the re-reaction of the mixed gas, in order to cooperate with the change of the fuel demand end, the first three-way valve 301 is adjusted in time to reduce the flow output ratio to the regenerator 5. At the same time, the third three-way valve 303 and the third three-way valve 303 are adjusted to reduce the flow to the ammonia reactor 7 path. At the same time, the first flow control valve 2 at the rear end of the liquid ammonia tank 1 is quickly adjusted to reduce the total flow, and the second three-way valve 302 and the first flow control valve 2 are adjusted to ensure that the ammonia gas flow in the ammonia hydrogen production system does not change significantly. After the total flow decreases, judge the degree of ammonia decomposition reaction, and adjust each three-way valve to a stable state.

[0040] The ammonia hydrogen production system applicable to an internal combustion engine 12 or a large power unit in the present invention improves the heat utilization rate by means of waste heat of engine cooling water, recuperation of the mixture gas, and staged heating of waste heat of the exhaust gas; realizes the re-decomposition of ammonia by controlling the reflux of the reaction gas, controls the reaction process of ammonia hydrogen production, and further controls the intake gas components and their contents of the internal combustion engine 12. In addition, in response to the change in fuel demand during variable working conditions of the internal combustion engine 12, the present invention proposes a corresponding control strategy to achieve a rapid response to the change in fuel demand and improve the instantaneous response sensitivity of the ammonia and hydrogen flow rates. The ammonia hydrogen production system proposed by the present invention has a high energy utilization rate, can achieve precise control from partial decomposition to complete decomposition of ammonia, and the mixture gas components and flow rate generated by ammonia decomposition have good responsiveness to the load change of the internal combustion engine 12. The use of this system is of great significance for the large-scale application of ammonia-hydrogen melting internal combustion engines 12 and power systems.

[0041] The ammonia hydrogen production system applicable to an internal combustion engine or a large power unit in the present invention not only utilizes the waste heat of the internal combustion engine, but also recovers the waste heat of the ammonia-hydrogen mixture gas after the reaction, improves the intake efficiency, and has a higher energy utilization efficiency; at the same time, the ammonia hydrogen production system proposed by the present invention can realize multiple reactions of the ammonia-hydrogen mixture gas. With the corresponding control strategy, it can effectively control the degree of ammonia decomposition, flexibly adjust the ammonia-hydrogen ratio and total flow rate of the internal combustion engine intake, and solve the problems of low ammonia decomposition efficiency and poor responsiveness to the working conditions of the internal combustion engine in the existing system.

[0042] Compared with the existing one-time reaction type ammonia hydrogen production system, the ammonia hydrogen production system proposed by the present invention shortens the pipeline from the regulating end (the second three-way valve) to the fuel supply system, has better sensitivity to variable working conditions, and the flow rate changes more rapidly. At the same time, the control strategy proposed by the present invention can be optimized in cooperation with the vehicle ECU, and each specific control parameter can be obtained through tests and optimizations for different models of internal combustion engines.

[0043] It should be noted that for those skilled in the art, obviously the present invention is not limited to the details of the above exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be embraced within the present invention, and any reference signs in the claims should not be regarded as limiting the claimed rights involved.

[0044] In this specification, specific examples are used to illustrate the principles and implementation manners of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation manners and application scopes. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. A recuperative and reactive internal combustion engine waste heat ammonia hydrogen production system, characterized in that, It includes an ammonia tank, a vaporization chamber, a cooling water tank, an internal combustion engine, a second flow control valve, a third flow control valve, a fuel supply system, a regenerator, and an ammonia reactor; the outlet of the ammonia tank is communicated with the fuel inlet of the vaporization chamber, and the fuel outlet of the vaporization chamber is communicated with the inlets of the second flow control valve and the third flow control valve; The cooling water tank is used to cool the internal combustion engine. The cooling water outlet of the vaporization chamber is communicated with the inlet of the cooling water tank, the outlet of the cooling water tank is communicated with the cooling water inlet of the internal combustion engine, and the cooling water outlet of the internal combustion engine is communicated with the cooling water inlet of the vaporization chamber; The outlet end of the third flow control valve is communicated with the inlet end of the fuel supply system, and the outlet end of the fuel supply system is communicated with the internal combustion engine; the outlet end of the second flow control valve is communicated with the first inlet of the regenerator, the first outlet of the regenerator is communicated with the first inlet of the regenerator, the first outlet of the regenerator is communicated with the inlet of the ammonia reactor, the outlet of the ammonia reactor is communicated with the second inlet of the regenerator, the second outlet of the regenerator is communicated with the second inlet of the regenerator, and the second outlet of the regenerator is communicated with the inlet end of the fuel supply system; The ammonia reactor is arranged in the exhaust pipe of the internal combustion engine.

2. The ammonia production system by using waste heat of the regenerative re-reaction internal combustion engine according to claim 1, characterized in that, A heater is further arranged between the ammonia reactor and the regenerator, and the heater is arranged in the exhaust pipe of the internal combustion engine.

3. The waste heat ammonia hydrogen production system for a regenerative re-reactive internal combustion engine according to claim 2, wherein The ammonia reactor is located upstream of the exhaust pipe of the internal combustion engine, and the heater is located downstream of the exhaust pipe of the internal combustion engine.

4. The waste heat ammonia hydrogen production system for a regenerative re-reactive internal combustion engine according to claim 2, wherein The heater adopts a finned heat exchanger.

5. The heat regenerative and re-reactive internal combustion engine waste heat ammonia hydrogen production system according to claim 2, characterized in that, A temperature sensor, an ammonia sensor, and a first three-way valve are sequentially arranged between the outlet of the ammonia reactor and the second inlet of the regenerator; a second three-way valve is arranged between the third interface of the first three-way valve and the inlet of the ammonia reactor, and a third three-way valve is arranged between the first outlet of the regenerator and the heater; the third interface of the second three-way valve is communicated with the third interface of the third three-way valve.

6. The internal combustion engine waste heat ammonia hydrogen production system with regenerative re-reaction according to claim 5, characterized in that, The second flow control valve, the third flow control valve, the heater, the temperature sensor, the ammonia sensor, the first three-way valve, the second three-way valve, and the third three-way valve are all electrically connected to the control module.

7. The waste heat ammonia hydrogen production system for a regenerative re-reaction internal combustion engine according to claim 1, characterized in that, A first flow control valve is arranged between the ammonia tank and the vaporization chamber, and the first flow control valve is electrically connected to the control module.

8. The hydrogen production system from ammonia using waste heat of a regenerative re-reactive internal combustion engine according to claim 1, characterized in that, The regenerator adopts a plate heat exchanger.

9. The control method of the internal combustion engine waste heat ammonia hydrogen production system with regenerative re-reaction according to any one of claims 1 to 8, characterized in that, It includes the following working conditions, Stable fuel supply state: Stable operation is the main operating condition of an internal combustion engine. Under this condition, the demand for fuel by the internal combustion engine is stable. When the fuel is stably supplied, ammonia flows out of the liquid ammonia tank under the control of the first flow control valve, passes through the vaporization chamber, and is branched under the control of the second flow control valve and the second flow control valve. Part of it directly flows into the fuel supply system, mixes with the ammonia-hydrogen mixture, and then participates in combustion. Part of it passes through the regenerator, the third three-way valve, the heater, and the ammonia reactor to decompose and produce hydrogen. The temperature sensor and ammonia sensor at the outlet of the ammonia reactor detect the temperature and ammonia concentration of the ammonia-hydrogen mixture. If the ammonia concentration in the mixture is low, it is considered that the degree of ammonia decomposition reaction reaches the ideal state. Then, the passage from the first three-way valve to the regenerator is fully opened, and the passage to the second three-way valve is closed. All the ammonia-hydrogen mixture directly enters the fuel supply system, mixes with ammonia, and then completes combustion in the internal combustion engine. If the degree of ammonia decomposition reaction does not reach the ideal state, analyze the data of the temperature sensor. If the temperature of the temperature sensor is low, the incomplete ammonia decomposition is mainly due to the low reaction temperature. In this case, open the loop from the first three-way valve to the second three-way valve, close the loop from the second three-way valve to the ammonia reactor, and fully open the loop to the first three-way valve. Part of the ammonia-hydrogen mixture passes through the loop of the second three-way valve and the third three-way valve, and then remixes with fresh ammonia. After that, it passes through the heater and the ammonia reactor to realize reheating and re-reaction of the ammonia-hydrogen mixture. Continuously adjust the opening degree of the mixture of each three-way valve to adjust the ratio of the re-reacted and reheated mixture until the hydrogen-ammonia ratio at the outlet of the ammonia reactor meets the requirements of the internal combustion engine. If the degree of ammonia decomposition does not reach the ideal state and the temperature of the ammonia-hydrogen mixture is high, the mixture does not need to be reheated. Part of the ammonia-hydrogen mixture directly flows into the ammonia reactor through the second three-way valve for re-reaction. Continuously adjust the ratio of the re-reacted mixture until the hydrogen-ammonia ratio at the outlet of the ammonia reactor meets the requirements of the internal combustion engine. Increase in fuel demand: Under the conditions of vehicle acceleration or uphill, the power of the internal combustion engine increases, and the demand for ammonia-hydrogen fuel becomes larger. If the first three-way valve is in the state where the flow to the regenerator is fully open and the flow to the second three-way valve is fully closed at this time, at this time, the mixture has not undergone re-reaction. After adjusting the first flow control valve, the second flow control valve, and the third flow control valve so that the total flow meets the requirements of the internal combustion engine, then judge the degree of ammonia decomposition reaction, and adjust each three-way valve until the hydrogen-ammonia ratio at the outlet of the ammonia reactor meets the requirements of the internal combustion engine. The adjustment method is the same as the adjustment steps in the stable state. If the fuel demand increases during the re-reaction of the mixture, in order to cooperate with the change in the fuel demand side, the first three-way valve is adjusted in a timely manner to increase the flow output ratio to the regenerator. At the same time, the second three-way valve and the third three-way valve are adjusted in cooperation to increase the flow to the ammonia reactor passage. At the same time, the first flow control valve at the rear end of the liquid ammonia tank quickly adjusts to increase the total flow, and adjusts the second three-way valve and the first flow control valve to ensure that the ammonia flow in the ammonia hydrogen production system does not change significantly. After the total flow increases, judge the degree of ammonia decomposition reaction, and adjust each three-way valve to the stable state. Decrease in fuel demand: Under the conditions of vehicle deceleration or downhill, the power of the internal combustion engine decreases, and the demand for ammonia-hydrogen fuel decreases. If the first three-way valve is in the state where the flow rate to the regenerator is fully open and the flow rate to the second three-way valve is fully closed at this time, at this time, the mixed gas does not undergo a re-reaction. After adjusting the first flow control valve, the second flow control valve, and the third flow control valve so that the total flow rate meets the requirements of the internal combustion engine in the state, then judge the degree of ammonia decomposition reaction, and adjust each three-way valve until the hydrogen-ammonia ratio at the outlet of the ammonia reactor meets the requirements of the internal combustion engine. The adjustment method is the same as the adjustment steps in the stable state; If the fuel demand decreases during the re-reaction of the mixed gas, in order to cooperate with the change in the fuel demand side, the first three-way valve is adjusted in a timely manner to reduce the flow output ratio to the regenerator; at the same time, the third three-way valve and the third three-way valve are adjusted to reduce the flow rate to the ammonia reactor path; at the same time, the first flow control valve at the rear end of the liquid ammonia tank is quickly adjusted to reduce the total flow rate, and the second three-way valve and the first flow control valve are adjusted to ensure that the ammonia flow rate in the ammonia hydrogen production system does not change significantly; after the total flow rate decreases, judge the degree of ammonia decomposition reaction, and adjust each three-way valve to a stable state.

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