Hydrogen fuel engine exhaust gas treatment device and control method thereof

Abstract

The present invention relates to a hydrogen fuel engine exhaust gas treatment device and a control method thereof. The exhaust gas treatment device includes a catalyst unit, a gas-water separation unit for gas-liquid separation, a gas-gas separation unit for separating N2, and an ammonia storage unit for performing an NH3 synthesis reaction. The inlet end of the catalyst unit is connected to the exhaust gas outlet of the hydrogen fuel engine, and the outlet end is connected to the gas-water separation unit. The gas outlet of the gas-water separation unit is connected to the gas-gas separation unit, and the non-N2 gas outlet of the gas-gas separation unit is connected to the ammonia storage unit. The ammonia storage unit is connected to the inlet end of the catalyst unit. The hydrogen fuel engine exhaust gas treatment device of the present invention can separate and recycle the exhaust gas of the hydrogen fuel engine, improve the utilization rate of hydrogen fuel, and protect the environment.

Description

Technical Field

[0001] The present invention relates to the field of hydrogen fuel engine exhaust systems, and in particular to a hydrogen fuel engine exhaust gas treatment device and a control method thereof. Background Art

[0002] For hydrogen fuel engines, there is a phenomenon of incomplete combustion of hydrogen in the cylinder. However, since hydrogen fuel engines do not have a dedicated exhaust after-treatment system, the incompletely burned hydrogen in the engine cylinder will be directly discharged from the cylinder into the atmosphere. On the one hand, the discharged hydrogen will pollute the environment. On the other hand, hydrogen is a flammable and explosive gas and direct discharge poses a safety hazard. The incompletely burned hydrogen in the hydrogen fuel engine cylinder needs to be treated.

[0003] Hydrogen fuel engines are generally filled with green hydrogen, with a hydrogen concentration of 99.99%. The oxygen for hydrogen fuel engine combustion comes from the air, which also contains a large amount of nitrogen. The main combustion reaction during the combustion process of hydrogen fuel engines is: 2H2+O2=2H2O, accompanied by a side reaction: N2+XO2=2NO x The exhaust gas after combustion in the cylinder of a hydrogen fuel engine mainly contains H2O, NO x , and a small amount of unreacted H2, N2, O2. H2O, N2, and O2 can be discharged directly into the atmosphere without treatment, but NO x It is a toxic gas and will pollute the environment if discharged directly into the atmosphere.

[0004] Therefore, there is an urgent need to provide a hydrogen fuel engine exhaust gas treatment device that can reduce the emission of harmful gases and improve the utilization rate of hydrogen fuel. Summary of the Invention

[0005] One of the purposes of the present invention is to provide a hydrogen fuel engine exhaust treatment device to solve the problem of incomplete combustion of hydrogen in the cylinder of a hydrogen fuel engine in the prior art; the second purpose is to provide a control method for a hydrogen fuel engine exhaust treatment device.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0007] In a first aspect, the present invention provides an exhaust gas treatment device for a hydrogen fuel engine, which includes a catalyst unit, an air-water separation unit for gas-liquid separation, a gas-gas separation unit for separating N2, and an ammonia storage unit for performing an NH3 synthesis reaction. The inlet end of the catalyst unit is connected to the exhaust gas outlet of the hydrogen fuel engine, and the outlet end is connected to the air-water separation unit. The gas outlet of the air-water separation unit is connected to the air-gas separation unit, the non-N2 gas outlet of the air-gas separation unit is connected to the ammonia storage unit, and the ammonia storage unit is connected to the inlet end of the catalyst unit.

[0008] According to the above technical means, the catalyst unit can use the reducing agent NH3 to reduce NO in the exhaust gas of the hydrogen fuel engine. x The catalytic reduction treatment is carried out to reduce the emission of harmless gases. The gas-water separation unit can separate and discharge the liquid in the exhaust gas of the hydrogen fuel engine. The gas-gas separation unit can separate and discharge the N2 in the exhaust gas of the hydrogen fuel engine. The ammonia storage unit can use the H2 and NO in the exhaust gas of the hydrogen fuel engine to synthesize the reducing agent NH3. The separation and recycling of the exhaust gas of the hydrogen fuel engine reduces the emission of harmful gases, improves the utilization rate of hydrogen fuel and protects the environment.

[0009] Furthermore, the gas-water separation unit includes a cylinder and an gas-water separation inner cavity, the cylinder is provided with an gas-water separation unit air inlet, an gas-water separation unit air outlet pipe located at the gas outlet of the gas-water separation unit, and a gas-water separation unit drain outlet, one end of the gas-water separation unit air outlet pipe is located in the gas-water separation inner cavity and is provided with a first diaphragm capable of intercepting H2O, and the other end is located outside the cylinder, and the gas-water separation unit air outlet pipe is connected to the gas-gas separation unit.

[0010] According to the above technical means, the gas-liquid separation unit separates the incoming hydrogen fuel engine exhaust gas into gas and liquid, intercepts H2O through the first diaphragm, and improves the efficiency of gas-liquid separation.

[0011] Furthermore, the gas-water separation inner cavity is provided with a plurality of guide plates, and the plurality of guide plates are respectively tangent to the outer wall of the gas outlet pipe of the gas-water separation unit.

[0012] According to the above technical means, multiple guide plates are arranged to be tangent to the outer wall of the outlet pipe of the gas-water separation unit respectively. The exhaust gas of the hydrogen fuel engine entering the gas-water separation unit is affected by the guide plates and has a reduced flow rate and moves in a vortex shape, colliding with the gas-water separation cavity. The easily liquefied H2O will condense to form droplets and then separate, further improving the efficiency of gas-liquid separation.

[0013] Furthermore, a second diaphragm capable of intercepting N2 and a hydrogen quality sensor are provided in the gas-gas separation unit. The hydrogen quality sensor is located between the second diaphragm and the non-N2 gas outlet of the gas-gas separation unit.

[0014] According to the above technical means, the gas input into the gas-gas separation unit is separated into N2 by the second diaphragm, and the hydrogen mass sensor can measure the mass of H2 recovered in the gas-gas separation unit.

[0015] Furthermore, the inner cavity between the air inlet of the gas-gas separation unit and the second diaphragm is connected to the nitrogen separation unit, and the nitrogen separation unit is provided with a third diaphragm for only allowing N2 to pass through.

[0016] According to the above technical means, the third diaphragm can intercept gases other than N2 and discharge N2 from the gas-gas separation unit.

[0017] Furthermore, the ammonia storage unit is provided with an ammonia storage, an ammonia quality sensor located in the ammonia storage, and a hydrogen replenishing structure for replenishing H2 into the ammonia storage.

[0018] According to the above technical means, the NH3 synthesis reaction can be carried out in the ammonia storage, and the ammonia quality sensor can detect the quality of NH3 in the ammonia storage. When the quality of H2 input into the ammonia storage unit from the gas-gas separation unit is not enough to synthesize the required NH3, the required H2 can be input into the ammonia storage through the hydrogen replenishment structure.

[0019] Furthermore, the ammonia storage unit is connected to the catalyst unit via an ammonia delivery pipeline, and an ammonia injection structure for injecting NH3 into the catalyst unit is provided at one end of the ammonia delivery pipeline close to the catalyst unit.

[0020] According to the above technical means, the ammonia injection structure can inject NH3 in the ammonia storage unit into the catalyst unit to reduce the NO x Perform reduction conversion.

[0021] Furthermore, the catalyst unit is provided with a front NOx filter located at the inlet end of the catalyst unit. x sensor and the post NOx located at the outlet end of the catalyst unit x sensor.

[0022] According to the above technical means, according to the former NO x Sensor and rear NO x The sensor can detect NOx in the exhaust gas of hydrogen fuel engine when it enters and leaves the catalyst unit. x The mass of NO is calculated x conversion efficiency.

[0023] In a second aspect, the present invention provides a method for controlling a hydrogen fuel engine exhaust gas treatment device, the method comprising the following steps:

[0024] After the hydrogen fuel engine is started, the exhaust gas of the hydrogen fuel engine is input into the catalyst unit for NO x After the reduction conversion, the gas-liquid separation is carried out in the gas-water separation unit to obtain the gas separation product. The gas separation product is subjected to the gas-gas separation unit to remove N2 to obtain the non-N2 gas. The non-N2 gas is input into the ammonia storage unit to carry out the NH3 synthesis reaction. In this process, the NO in the catalyst unit is obtained. x Mass, calculate NO xThe mass of NH3 required for complete conversion m NH3 , using the ammonia storage unit to input a mass of m to the catalyst unit NH3 of NH3.

[0025] According to the above technical means, it is possible to obtain NO in the catalyst unit x Quality, using the ammonia storage unit to input NO into the catalyst unit x The mass required for complete conversion is m NH3 NH3 to NO x Reduction and conversion reduces the emission of harmful gases, protects the environment, and improves the utilization rate of hydrogen fuel.

[0026] Furthermore, the ammonia storage unit is used to input a mass of m into the catalyst unit. NH3 The NH3 process adopts the following control process:

[0027] Get the real-time NH3 mass m in the ammonia storage unit NH31 , determine m NH31 Is it greater than m? NH3 , if m NH31 Greater than m NH3 , then the mass m is directly input to the catalyst unit through the ammonia storage unit NH3 of NH3; if m NH31 Less than m NH3 , then calculate the NH3 mass ε that needs to be supplemented in the ammonia storage unit NH3 =m NH3 -m NH31 And the composite mass is ε NH3 The mass of H2 required to produce NH3 is m H21 , input mass m into the ammonia storage unit H21 The H2 undergoes NH3 synthesis reaction and inputs a mass of m into the catalyst unit through the ammonia storage unit. NH3 of NH3.

[0028] According to the above technical means, when m NH31 Greater than m NH3 When the mass m is directly input to the catalyst unit through the ammonia storage unit NH3 of NH3; when m NH31 Less than m NH3 When the mass m is input to the ammonia storage unit H21 The H2 undergoes NH3 synthesis reaction to produce a mass of ε NH3 =m NH3 -m NH31 NH3, and input a mass of m to the catalyst unit through the ammonia storage unit NH3 of NH3.

[0029] Furthermore, the real-time H2 mass m in the gas-gas separation unit is obtained. H20 , determine m H20 Is it greater than m? H21 , if m H20 Greater than m H21 , then directly input the mass m into the ammonia storage unit through the gas separation unit H21 H2; if m H20 Less than m H21 , then calculate the H2 mass ε that needs to be supplemented in the ammonia storage unit H2 =m H21 -m H20 , a mass of m is input to the ammonia storage unit through the gas separation unit H20 H2, and at the same time, an external source device is used to input a mass of ε into the ammonia storage unit. H2 H2.

[0030] According to the above technical means, when m H20 Greater than m H21 , can directly input mass m into the ammonia storage unit through the gas separation unit H21 H2; when m H20 Less than m H21 , can be fed into the ammonia storage unit through the gas separation unit with a mass of m H20 At the same time, the H2 with a mass of ε is input to the ammonia storage unit through an external device. H2 =m H21 -m H20 H2.

[0031] Furthermore, the NO at the inlet of the catalyst unit is obtained. x Mass m Nox0 and NO at the outlet of the catalyst unit x Mass m NOx1 , calculate the NO in the catalyst unit x Reduction-converted NO x Conversion efficiency η = 1-m NOx1 / m NOx0 , determine whether η is greater than the set target value a, if η is greater than a, then m NH3 NO is the exhaust gas of the hydrogen fuel engine input into the catalyst unit. x The mass of NH3 required for complete conversion m NH30 If η is less than a, the calculation requires a secondary conversion of NO x Mass m NOx2 =m NOx1 -(1-a)m NOx0 and mass is m NOx2NO x The mass of NH3 required for complete conversion m NH32 , m NH3 =m NH30 +m NH32 .

[0032] According to the above technical means, the exhaust gas of the hydrogen fuel engine is converted into NO by the catalyst unit. x When the conversion efficiency η of the reduction treatment is less than the set target value a, the NO x Providing NH3 of corresponding quality can further reduce the emission of harmful gases.

[0033] Beneficial effects of the present invention:

[0034] The exhaust gas treatment device provided by the present invention includes a catalyst unit, an air-water separation unit, an air-gas separation unit and an ammonia storage unit. The air-water separation unit separates H2O from the exhaust gas, the air-gas separation unit separates N2 from the exhaust gas, and the ammonia storage unit performs an NH3 synthesis reaction. The exhaust gas of the hydrogen fuel engine passes through the catalyst unit, the air-water separation unit, the air-gas separation unit and the ammonia storage unit in sequence, and is mixed with the exhaust gas of the freshly input hydrogen fuel engine in the catalyst unit. NH3 is used to perform NO synthesis in the catalyst unit. x The reduction conversion can realize the separation and recycling of hydrogen fuel engine exhaust, reduce the emission of harmful gases, thereby improving the utilization rate of hydrogen fuel and protecting the environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 Schematic diagram of the structure of the hydrogen fuel engine exhaust treatment device of the present invention, wherein the dotted lines represent electrical connections;

[0036] Figure 2 Schematic diagram of the connection between the gas-water separation unit, the gas-gas separation unit and the nitrogen separation unit in the present invention;

[0037] Figure 3 is a cross-sectional view of the gas-water separation unit of the present invention;

[0038] Figure 4 is a schematic diagram of an ammonia storage unit in the present invention;

[0039] Figure 5 It is a flow chart of the control method of the hydrogen fuel engine exhaust treatment device in the present invention.

[0040] Among them, 1-exhaust manifold; 2-exhaust main pipe; 3-catalytic converter unit; 31-front NO x Sensor; 32-rear NO xSensor; 4-gas-water separation unit; 41-cylinder; 42-gas-water separation inner cavity; 43-gas-water separation unit air inlet; 44-gas-water separation unit air outlet; 45-gas-water separation unit drain outlet; 46-first diaphragm; 47-guide plate; 48-gas-water separation unit drain pipe; 5-gas-gas separation unit; 51-second diaphragm; 52-hydrogen quality sensor; 53-one-way valve; 54-hydrogen return valve; 6-ammonia storage unit; 61-ammonia quality sensor; 62-hydrogen replenishment structure; 63-ammonia injection structure; 64-external hydrogen injection valve; 65-ammonia injection valve; 7-nitrogen separation unit; 71-third diaphragm; 72-nitrogen exhaust pipe; 73-nitrogen control valve; 8-controller unit. DETAILED DESCRIPTION

[0041] The following describes the embodiments of the present invention with reference to the accompanying drawings and preferred embodiments. Those skilled in the art will readily appreciate the other advantages and benefits of the present invention from the disclosure herein. The present invention may also be implemented or applied through various other specific embodiments, and the various details in this specification may be modified or altered based on different viewpoints and applications without departing from the spirit of the present invention. It should be understood that the preferred embodiments are intended only to illustrate the present invention and are not intended to limit the scope of protection of the present invention.

[0042] It should be noted that the illustrations provided in the following embodiments are merely schematic illustrations of the basic concept of the present invention. Therefore, the illustrations only show components related to the present invention and are not drawn according to the number, shape, and size of components in actual implementation. In actual implementation, the type, quantity, and proportion of each component may be changed arbitrarily, and the component layout may also be more complex.

[0043] The basic embodiment of the present invention proposes a hydrogen fuel engine exhaust gas treatment device, see Figure 1 As shown, the exhaust gas treatment device includes a catalyst unit 3, a gas-water separation unit 4 for gas-liquid separation, a gas-gas separation unit 5 for separating N2, and an ammonia storage unit 6 for performing an NH3 synthesis reaction. The inlet end of the catalyst unit 3 is connected to the exhaust gas outlet of the hydrogen fuel engine, and the outlet end is connected to the gas-water separation unit 4. The gas outlet of the gas-water separation unit 4 is connected to the gas-gas separation unit 5. The non-N2 gas outlet of the gas-gas separation unit 5 is connected to the ammonia storage unit 6. The ammonia storage unit 6 is connected to the inlet end of the catalyst unit 3. The exhaust gas of the hydrogen fuel engine enters the catalyst unit 3, and the ammonia storage unit 6 inputs NH3 into the catalyst unit 3, using NH3 to remove NO in the exhaust gas in the catalyst unit 3. xThe gas after reduction conversion enters the gas-water separation unit 4 for gas-liquid separation to obtain liquid separation and gas separation. The liquid separation is discharged from the liquid outlet of the gas-water separation unit 4. The gas separation enters the gas-gas separation unit 5 from the gas outlet of the gas-water separation unit 4 for N2 separation to obtain N2 and non-N2 gas. N2 is discharged from the N2 gas outlet of the gas-gas separation unit 5. The non-N2 gas is input from the non-N2 gas outlet to the ammonia storage unit 6 for NH3 synthesis reaction. The synthesized NH3 is then input to the catalyst unit 3 for NO x The hydrogen fuel engine exhaust gas treatment device provided by the present invention utilizes NH3 to reduce NO in the catalyst unit 3. x Carry out reduction conversion, reduce the emission of harmful gases, improve the utilization rate of hydrogen fuel, and protect the environment.

[0044] It should be noted that the exhaust gas of hydrogen fuel engines mainly contains H2O, NO x When the gas from the ammonia storage unit 6 input to the catalyst unit 3 is mixed with the exhaust gas from the hydrogen fuel engine entering the catalyst unit 3, the gas in the catalyst unit 3 is NH3, H2O, NO x , H2, N2 and O2, can undergo chemical reaction: 4NO x +4NH3+(3-2x)O2=4N2+6H2O, using NH3 as a reducing agent to reduce harmful gas NO x Converted into harmless gas; the non-N2 gas obtained in the gas-gas separation unit 5 refers to gas other than N2, and the non-N2 gas can be discharged from the non-N2 gas outlet of the gas-gas separation unit 5; a chemical reaction can occur in the ammonia storage unit 6: NO+H2→NH3, and the reducing agent NH3 is synthesized by utilizing NO and H2 in the exhaust gas of the hydrogen fuel engine, and the H2 that has not been completely reacted in the exhaust gas of the hydrogen fuel engine is reused, thereby improving the utilization rate of the hydrogen fuel.

[0045] In some specific embodiments, the catalyst unit 3 may be an SCR selective catalyst, which specifically treats NO in the exhaust gas of the hydrogen fuel engine. x The reduction conversion reduces the emission of harmful gases and protects the environment.

[0046] In some specific embodiments, an exhaust manifold 1 and an exhaust main pipe 2 may be connected between the exhaust outlet of the hydrogen fuel engine and the inlet end of the catalyst unit 3, so that the exhaust gas of the hydrogen fuel engine passes through the exhaust manifold 1 and the exhaust main pipe 2 in sequence into the catalyst unit 3 for reduction conversion, so as to control the emission of the exhaust gas.

[0047] In a preferred embodiment of the present invention, see Figure 2-3As shown, the gas-water separation unit 4 includes a cylinder 41 and a gas-water separation inner cavity 42. The cylinder 41 is provided with a gas-water separation unit air inlet 43, a gas-water separation unit air outlet pipe 44 located at the gas outlet of the gas-water separation unit 4, and a gas-water separation unit water outlet 45. One end of the gas-water separation unit air outlet pipe 44 is located in the gas-water separation inner cavity 42 and is provided with a first diaphragm 46 capable of intercepting H2O, and the other end is located outside the cylinder 41. The gas-water separation unit air outlet pipe 44 is connected to the gas-gas separation unit 5. The gas-water separation unit 4 separates the incoming tail gas into gas and liquid. The liquid fraction after gas-liquid separation is discharged through the gas-water separation unit water outlet 45. The gas fraction after gas-liquid separation passes through the first diaphragm 46 and is input from the gas-water separation unit air outlet pipe 44 to the gas-gas separation unit 5. The first diaphragm 46 can intercept H2O in the gas fraction, further improving the gas-liquid separation efficiency of the gas-water separation unit 4.

[0048] In some specific embodiments, the liquid separation separated by the gas-water separation unit 4 can be directly discharged through the gas-water separation unit drain port 45, or an gas-water separation unit drain pipe 48 can be connected to the gas-water separation unit drain port 45 to discharge the liquid separation separated by the gas-water separation unit 4 through the gas-water separation unit drain port 45 and the gas-water separation unit drain pipe 48.

[0049] In a preferred embodiment of the present invention, the gas-water separation unit 4 can adopt a rotary separation structure, wherein the gas-water separation unit air inlet 43 can adopt a volute air inlet, see Figure 2-3 As shown, the gas-water separation cavity 42 is provided with a plurality of guide plates 47, which are tangent to the outer wall of the gas-water separation unit outlet pipe 44. The tail gas entering the gas-water separation cavity 42 through the gas-water separation unit inlet 43 is affected by the guide plates 47, and the flow rate is reduced, and the tail gas moves in a vortex-like manner, colliding with the gas-water separation cavity 42. The H2O in the tail gas, which is easily liquefied, condenses to form droplets, and then falls to the bottom of the gas-water separation cavity 42 due to gravity and is discharged through the gas-water separation unit drain port 45. The NO in the tail gas, which is not easily liquefied, is discharged. x , N2, H2, O2 and NH3 will enter the gas-gas separation unit 5 through the gas-water separation unit outlet pipe 44, further improving the gas-liquid separation efficiency of the gas-water separation unit 4.

[0050] In some specific embodiments, a one-way valve 53 is further provided on the pipeline connecting the gas-gas separation unit 5 and the gas-water separation unit 4 to prevent the gas in the gas-gas separation unit 5 from entering the gas-water separation unit 4 .

[0051] In a preferred embodiment of the present invention, see Figure 1As shown, the gas-gas separation unit 5 is provided with a second diaphragm 51 capable of intercepting N2 and a hydrogen mass sensor 52. The hydrogen mass sensor 52 is located between the second diaphragm 51 and the non-N2 gas outlet of the gas-gas separation unit 5. The second diaphragm 51 separates N2 from the gas input into the gas-gas separation unit 5. The separated N2 is located in the inner cavity between the second diaphragm 51 and the gas inlet of the gas-gas separation unit 5, while the non-N2 gas is located in the inner cavity between the second diaphragm 51 and the non-N2 gas outlet of the gas-gas separation unit 5. The hydrogen mass sensor 52 can measure the mass of H2 in the non-N2 gas.

[0052] In some specific embodiments, a hydrogen return valve 54 may be provided on the pipeline connecting the gas-gas separation unit 5 and the ammonia storage unit 6 to control the emission of the gas input from the gas-gas separation unit 5 to the ammonia storage unit 6 .

[0053] In a preferred embodiment of the present invention, see Figure 1 As shown, the inner cavity between the gas inlet and the second diaphragm 51 of the gas-gas separation unit 5 is connected to the nitrogen separation unit 7. A third diaphragm 71 is provided in the nitrogen separation unit 7, which allows only N2 to pass through. The gas-gas separation unit 5 is connected to the nitrogen separation unit 7 through the N2 gas outlet. The N2 separated in the gas-gas separation unit 5 enters the nitrogen separation unit 7 through the N2 gas outlet and is then discharged from the gas outlet of the nitrogen separation unit 7 through the third diaphragm 71.

[0054] It should be noted that the first diaphragm 46 , the second diaphragm 51 and the third diaphragm 71 can all be purchased commercially or prepared by oneself.

[0055] In some specific embodiments, the N2 in the nitrogen separation unit 7 can be discharged directly, or a nitrogen exhaust pipe 72 can be connected to the outlet of the nitrogen separation unit 7 so that the N2 in the nitrogen separation unit 7 is discharged through the nitrogen exhaust pipe 72; the outlet of the nitrogen exhaust pipe 72 can be connected to the gas-water separation unit drain pipe 48; and a nitrogen control valve 73 can be provided on the pipeline connecting the nitrogen separation unit 7 and the gas-gas separation unit 5 to control the emission of N2.

[0056] In a preferred embodiment of the present invention, see Figure 1 As shown, the ammonia storage unit 6 is equipped with an ammonia reservoir, an ammonia quality sensor 61 located within the ammonia reservoir, and a hydrogen replenishment mechanism 62 for replenishing H2 into the ammonia reservoir. When non-N2 gas from the gas-gas separation unit 5 enters the ammonia storage unit 6, NO and H2 in the non-N2 gas enter the ammonia reservoir to undergo an NH3 synthesis reaction. If a certain mass of NH3 needs to be synthesized but the H2 mass provided by the gas-gas separation unit 5 is insufficient, the required H2 mass is fed into the ammonia storage unit 6 via the hydrogen replenishment mechanism 62.

[0057] In some specific embodiments, the hydrogen replenishing structure 62 may be provided with an external hydrogen injection valve 64 , which can control the replenishment of H 2 . The hydrogen replenishing structure 62 may be connected to a hydrogen fuel storage device.

[0058] In a preferred embodiment of the present invention, see Figure 1 and Figure 4 As shown, the ammonia storage unit 6 is connected to the catalyst unit 3 through an ammonia delivery pipeline. An ammonia injection structure 63 for injecting NH3 into the catalyst unit 3 is provided at one end of the ammonia delivery pipeline close to the catalyst unit 3. When the mass of NH3 in the ammonia storage unit 6 is sufficient to remove NO in the catalyst unit 3, the ammonia storage unit 6 is connected to the catalyst unit 3 through an ammonia delivery pipeline. x When the conversion of NO is complete, the NH3 in the ammonia storage unit 6 is injected into the catalyst unit 3 through the ammonia injection structure 63. x Perform reduction conversion.

[0059] In some specific embodiments, an ammonia injection valve 65 is provided on the ammonia delivery pipeline. The ammonia injection valve 65 is located between the ammonia injection structure 63 and the ammonia storage unit 6 and can control the emission of the gas input from the ammonia storage unit 6 to the catalyst unit 3.

[0060] In a preferred embodiment of the present invention, see Figure 1 As shown, the catalyst unit 3 is provided with a front NO x The sensor 31 and the post NOx at the outlet of the catalyst unit 3 x Sensor 32, when the exhaust gas of the hydrogen fuel engine passes through the catalyst unit 3, x Sensor 31 detects NOx before the exhaust gas of the hydrogen fuel engine enters the catalyst unit 3. x The quality of the NO x Sensor 32 detects NOx when hydrogen fuel engine exhaust gas comes out of catalyst unit 3. x The mass of NO x conversion efficiency.

[0061] Based on the above technical solution, the problem of incomplete hydrogen combustion and harmful substances in the exhaust gas of hydrogen fuel engines in the prior art that pollute the environment is solved. The hydrogen fuel exhaust gas treatment system provided by the present invention allows the exhaust gas of the hydrogen fuel engine to pass through the catalyst unit 3, the gas-water separation unit 4, the gas-gas separation unit 5 and the ammonia storage unit 6 in sequence, and then mix with the freshly input hydrogen fuel engine exhaust gas in the catalyst unit 3, and use the synthesized NH3 as a reducing agent to reduce the NO in the catalyst unit 3. xThe gas-water separation unit 4 separates H2O from the exhaust gas, the gas-gas separation unit 5 separates N2 from the exhaust gas, and the ammonia storage unit 6 performs an NH3 synthesis reaction. By separating and recycling the exhaust gas from the hydrogen fuel engine, the emission of harmful gases is reduced, the environment is protected, and the utilization rate of hydrogen fuel is improved.

[0062] In a second aspect, an embodiment of the present invention provides a method for controlling a hydrogen fuel engine exhaust gas treatment device, the method comprising the following steps:

[0063] After the hydrogen fuel engine is started, the exhaust gas of the hydrogen fuel engine is input into the catalyst unit 3 to perform NO x After the reduction conversion, the gas-liquid separation is carried out in the gas-water separation unit 4 to obtain the gas separation product. The gas separation product is subjected to the gas-gas separation unit 5 to remove N2 to obtain the non-N2 gas. The non-N2 gas is input into the ammonia storage unit 6 to carry out the NH3 synthesis reaction. In this process, the NO in the catalyst unit 3 is obtained. x Mass, calculate NO x The mass of NH3 required for complete conversion m NH3 , using the ammonia storage unit 6 to input a mass of m to the catalyst unit 3 NH3 of NH3.

[0064] As a preferred embodiment of the present invention, the ammonia storage unit 6 is used to input a mass of m into the catalyst unit 3. NH3 The NH3 process adopts the following control process:

[0065] Get the real-time NH3 mass m in the ammonia storage unit 6 NH31 , determine m NH31 Is it greater than m? NH3 , if m NH31 Greater than m NH3 , then the mass m is directly input to the catalyst unit 3 through the ammonia storage unit 6 NH3 of NH3; if m NH31 Less than m NH3 , then calculate the NH3 mass ε that needs to be input into the ammonia storage unit 6 NH3 =m NH3 -m NH31 And the composite mass is ε NH3 The mass of H2 required to produce NH3 is m H21 , input mass m to ammonia storage unit 6 H21 The H2 undergoes NH3 synthesis reaction and is fed to the catalyst unit 3 through the ammonia storage unit 6 with a mass of m NH3 of NH3. If m NH31 Greater than m NH3 , then open the ammonia injection valve 65, and inject a mass of m into the catalyst unit 3 through the ammonia injection structure 63NH3 of NH3; if m NH31 Less than m NH3 , then open the hydrogen return valve 54 and inject a mass of m directly into the ammonia storage unit 6 through the gas separation unit 5 H21 The H2 undergoes NH3 synthesis reaction in the ammonia storage unit 6 to obtain a mass of ε NH3 =m NH3 -m NH31 NH3, then open the ammonia injection valve 65, and inject a mass of m into the catalyst unit 3 through the ammonia injection structure 63 NH3 of NH3.

[0066] As a preferred embodiment of the present invention, the real-time H2 mass m in the gas separation unit 5 is obtained. H20 , determine m H20 Is it greater than m? H21 , if m H20 Greater than m H21 , then the mass m is directly input to the ammonia storage unit 6 through the gas separation unit 5. H21 H2; if m H20 Less than m H21 , then calculate the H2 mass ε that needs to be replenished in the ammonia storage unit 6 H2 =m H21 -m H20 , the mass m is input to the ammonia storage unit 6 through the gas separation unit 5. H20 At the same time, the H2 with a mass of ε is input to the ammonia storage unit 6 through an external device. H2 H2. If m H20 Greater than m H21 , then open the hydrogen return valve 54 and inject a mass of m directly into the ammonia storage unit 6 through the gas separation unit 5 H21 H2; if m H20 Less than m H21 , open the external hydrogen injection valve 64, and inject a mass of ε into the ammonia storage unit 6 through the hydrogen replenishment structure 62 H2 =m H21 -m H20 H2.

[0067] As a preferred embodiment of the present invention, the NO at the inlet of the catalyst unit 3 is obtained. x Mass m Nox0 and NO at the outlet of the catalyst unit 3 x Mass m NOx1 , calculate the NO in catalyst unit 3 x Reduction-converted NO x Conversion efficiency η = 1-m NOx1 / m NOx0 , determine whether η is greater than the set target value a, if η is greater than a, then mNH3 NO is the exhaust gas of the hydrogen fuel engine input to the catalyst unit 3 x The mass of NH3 required for complete conversion m NH30 If η is less than a, the calculation requires a secondary conversion of NO x Mass m NOx2 =m NOx1 -(1-a)m NOx0 and mass is m NOx2 NO x The mass of NH3 required for complete conversion m NH32 , m NH3 =m NH30 +m NH32 .

[0068] In order to better understand the technical concept of the present invention, the following is an explanation in combination with relatively comprehensive technical features.

[0069] See also Figure 1-4As shown, a preferred embodiment of the present invention provides an exhaust gas treatment device for a hydrogen fuel engine, the exhaust gas treatment device comprising a catalyst unit 3, a gas-water separation unit 4 for gas-liquid separation, a gas-gas separation unit 5 for separating N2, and an ammonia storage unit 6 for performing an NH3 synthesis reaction. The catalyst unit 3 is an SCR selective catalyst. The inlet end of the catalyst unit 3 is connected to the exhaust gas outlet of the hydrogen fuel engine through an exhaust manifold 1 and an exhaust main pipe 2. The outlet end of the catalyst unit 3 is connected to the gas-water separation unit 4. The gas-water separation unit 4 adopts a rotary separation structure. The gas outlet of the gas-water separation unit 4 is connected to the gas-gas separation unit 5. The non-N2 gas outlet of the gas-gas separation unit 5 is connected to the ammonia storage unit 6. The ammonia storage unit 6 is connected to the catalyst. The inlet end of the catalyzer unit 3 is connected, the gas-water separation unit 4 includes a cylinder 41 and an gas-water separation inner cavity 42, the cylinder 41 is provided with an air inlet 43 of the gas-water separation unit, an air outlet pipe 44 of the gas-water separation unit located at the gas outlet of the gas-water separation unit 4, and an air-water separation unit drain port 45, one end of the air-water separation unit air outlet pipe 44 is located in the gas-water separation inner cavity 42 and is provided with a first diaphragm 46 capable of intercepting H2O, and the other end is located outside the cylinder 41, the air outlet pipe 44 of the gas-water separation unit is connected to the gas-gas separation unit 5, and the air-water separation unit drain port 45 is connected to the air-water separation unit drain pipe 48, the air inlet 43 of the gas-water separation unit adopts a volute type air inlet, and the air-water separation inner cavity 42 is provided with a plurality of guide plates 47, and the plurality of guide plates 47 divide the gas into The gas separation unit 5 is tangent to the outer wall of the gas outlet pipe 44 of the gas-water separation unit. A one-way valve 53 is provided on the pipeline connecting the gas-gas separation unit 5 and the gas-water separation unit 4. A second diaphragm 51 capable of intercepting N2 and a hydrogen mass sensor 52 are provided in the gas-gas separation unit 5. The hydrogen mass sensor 52 is located between the second diaphragm 51 and the non-N2 gas outlet of the gas-gas separation unit 5. A hydrogen return valve 54 is provided on the pipeline connecting the gas-gas separation unit 5 and the ammonia storage unit 6. The inner cavity between the air inlet of the gas-gas separation unit 5 and the second diaphragm 51 is connected to the nitrogen separation unit 7. The nitrogen separation unit 7 is provided with a third diaphragm 71 for only N2 to pass through. The gas outlet of the nitrogen separation unit 7 is connected to a nitrogen exhaust pipe 72, and the outlet of the nitrogen exhaust pipe 72 is connected to the gas-water separation unit 7. On the separation unit drain pipe 48, a nitrogen control valve 73 is provided on the pipeline connecting the nitrogen separation unit 7 and the gas-gas separation unit 5. The ammonia storage unit 6 is provided with an ammonia storage, an ammonia quality sensor 61 located in the ammonia storage and a hydrogen replenishing structure 62 for replenishing H2 into the ammonia storage. The hydrogen replenishing structure 62 can be provided with an external hydrogen injection valve 64. The ammonia storage unit 6 is connected to the catalyst unit 3 through an ammonia delivery pipeline. An ammonia injection structure 63 for injecting NH3 into the catalyst unit 3 is provided at one end of the ammonia delivery pipeline close to the catalyst unit 3. An ammonia injection valve 65 is provided on the ammonia delivery pipeline. The ammonia injection valve 65 is located between the ammonia injection structure 63 and the ammonia storage unit 6. The catalyst unit 3 is provided with a front NOx located at the inlet end of the catalyst unit 3. xThe sensor 31 and the post NOx at the outlet of the catalyst unit 3 x Sensor 32.

[0070] In some specific embodiments, the hydrogen fuel engine exhaust treatment system is controlled by the controller unit 8, and the controller unit 8 is connected to the front NO x Sensor 31, rear NO x The sensors 32 are electrically connected to obtain the NOx before and after the hydrogen fuel engine exhaust is reduced and converted by the catalyst unit 3. x The controller unit 8 is electrically connected to the ammonia quality sensor 61, the external hydrogen injection valve 64, and the ammonia injection valve 65, respectively, and can obtain the quality of NH3 in the ammonia storage unit 6, and can also control the quality of H2 added to the ammonia storage unit 6 through the external hydrogen injection valve 64, and can also control the emission of the gas injected from the ammonia storage unit 6 to the catalyst unit 3 through the ammonia injection valve 65; the controller unit 8 is electrically connected to the hydrogen quality sensor 52 and the hydrogen return valve 54, respectively, and can obtain the quality of H2 in the gas-gas separation unit 5, and can control the emission of the gas input from the gas-gas separation unit 5 to the ammonia storage unit 6; the controller unit 8 is also electrically connected to the nitrogen control valve 73, and can control the emission of N2. Through the controller unit 8 and the front NO x Sensor 31, rear NO x The electrical connection of the sensor 32, the ammonia quality sensor 61, the external hydrogen injection valve 64, the ammonia injection valve 65, the hydrogen quality sensor 52, the hydrogen return valve 54, and the nitrogen control valve 73 realizes the automatic control of the hydrogen fuel engine exhaust treatment device and improves the utilization rate of hydrogen fuel.

[0071] In specific embodiments, see Figure 5 , provides a control method for a hydrogen fuel engine exhaust treatment device, the control method comprising:

[0072] S101, according to the previous NO x Sensor 31 detects NO x Concentration signal, calculate the NO concentration at the inlet of catalyst unit 3 x Mass m NOx0 , execute step S102;

[0073] S102, using NH3 to reduce NO based on catalyst unit 3 x Principle of generating N2 and H2O: 4NO x +4NH3+(3-2x)O2=4N2+6H2O, the calculated mass is m NOx0 NO x The mass of NH3 required for complete conversion is m NH30 , execute step S103;

[0074] S103, calculate NO in catalyst unit 3 x The total mass of NH3 required for complete conversion is m NH3 If there is no m NH32 , then m NH3 =m NH30 ; If there is m NH32 , then m NH3 =m NH30 +m NH32 , execute step S104;

[0075] S104, calculate the current NH3 mass m in the ammonia storage unit 6 according to the NH3 concentration signal detected by the ammonia mass sensor 61 NH31 , determine m NH31 Is it greater than m? NH3 , if m NH31 Greater than m NH3 , then execute step S110; if m NH31 Less than m NH30 , then execute step S105;

[0076] S105. Calculate the NH3 mass ε that needs to be supplemented to the ammonia storage unit 6 NH3 =m NH3 -m NH31 , based on the NH3 synthesis mechanism: NO+H2→NH3, the synthesis mass is calculated as ε NH3 The mass of H2 required to produce NH3 m H21 , execute step S106;

[0077] S106, calculate the H2 mass m in the current gas separation unit 5 according to the H2 concentration signal detected by the hydrogen mass sensor 52 H20 , determine m H20 Is it greater than m? H21 , if m H20 Greater than m H21 , then execute step S107; if m H20 Less than m H21 , then execute step S108;

[0078] S107, open the hydrogen return valve 54, and inject a mass of m directly into the ammonia storage unit 6 through the gas separation unit 5. H21 H2, execute step S110;

[0079] S108, calculate the H2 mass ε that needs to be replenished in the ammonia storage unit 6 H2 =m H21 -m H20 , execute step S109;

[0080] S109, open the external hydrogen injection valve 64, and inject a mass of ε into the ammonia storage unit 6 through the hydrogen replenishment structure 62. H2 H2, execute step S110;

[0081] S110, open the ammonia injection valve 65, and inject ammonia of mass m into the catalyst unit 3 through the ammonia injection structure 63. NH3 NH3, execute step S111;

[0082] S111, according to the NO x Sensor 32 detects NO x Concentration signal, calculate the NO at the outlet of catalyst unit 3 x Mass m NOx1 , calculate NO x Conversion efficiency η = 1-m NOx1 / m NOx0 , execute step S112;

[0083] S112, determine whether η is greater than the set target value a, if η is greater than a, execute step S114, if η is less than a, execute step S113;

[0084] S113, calculate the NO that needs to be secondary converted at the outlet of the catalyst unit 3 x Mass m NOx2 =m NOx1 -(1-a)m NOx0 , and according to m NOx2 Calculate the mass as m NOx2 NO x The NH3 compensation mass m required for complete conversion NH32 , execute step S103;

[0085] S114: End and enter the next control cycle.

[0086] The above embodiments are only preferred embodiments for fully illustrating the present invention, and the protection scope of the present invention is not limited thereto. Any equivalent substitution or modification made by those skilled in the art based on the present invention is within the protection scope of the present invention.

Claims

1. A hydrogen fuel engine exhaust gas treatment device, characterized by: The tail gas treatment device comprises a catalyst unit (3), a gas-water separation unit (4) for performing gas-liquid separation, a gas-gas separation unit (5) for separating N2, and an ammonia storage unit (6) for performing an NH3 synthesis reaction. The inlet end of the catalyst unit (3) is connected to the tail gas outlet of the hydrogen fuel engine, and the outlet end is connected to the gas-water separation unit (4). The gas outlet of the gas-water separation unit (4) is connected to the gas-gas separation unit (5). The non-N2 gas outlet of the gas-gas separation unit (5) is connected to the ammonia storage unit (6). The ammonia storage unit (6) is connected to the inlet end of the catalyst unit (3).

2. The exhaust gas treatment device according to claim 1, characterized in that: The gas-water separation unit (4) comprises a cylinder (41) and a gas-water separation inner cavity (42); the cylinder (41) is provided with a gas-water separation unit air inlet (43), a gas-water separation unit air outlet pipe (44) located at the gas outlet of the gas-water separation unit (4), and a gas-water separation unit water outlet (45); one end of the gas-water separation unit air outlet pipe (44) is located in the gas-water separation inner cavity (42) and is provided with a first diaphragm (46) capable of intercepting H2O, and the other end is located outside the cylinder (41); the gas-water separation unit air outlet pipe (44) is connected to the gas-gas separation unit (5).

3. The exhaust gas treatment device according to claim 2, characterized in that: The gas-water separation inner cavity (42) is provided with a plurality of guide plates (47), and the plurality of guide plates (47) are respectively tangent to the outer wall of the gas outlet pipe (44) of the gas-water separation unit.

4. The exhaust gas treatment device according to any one of claims 1 to 3, characterized in that: A second diaphragm (51) capable of intercepting N2 and a hydrogen quality sensor (52) are provided in the gas-gas separation unit (5); the hydrogen quality sensor (52) is located between the second diaphragm (51) and the non-N2 gas outlet of the gas-gas separation unit (5).

5. The exhaust gas treatment device according to claim 4, characterized in that: The inner cavity between the air inlet of the gas-gas separation unit (5) and the second diaphragm (51) is connected to the nitrogen separation unit (7), and the nitrogen separation unit (7) is provided with a third diaphragm (71) for only allowing N2 to pass through.

6. The exhaust gas treatment device according to any one of claims 1 to 3, characterized in that: The ammonia storage unit (6) is provided with an ammonia storage, an ammonia quality sensor (61) located in the ammonia storage, and a hydrogen replenishing structure (62) for replenishing H2 into the ammonia storage.

7. The exhaust gas treatment device according to any one of claims 1 to 3, characterized in that: The ammonia storage unit (6) is connected to the catalyst unit (3) via an ammonia delivery pipeline, and an ammonia injection structure (63) for injecting NH3 into the catalyst unit (3) is provided at one end of the ammonia delivery pipeline close to the catalyst unit (3).

8. The exhaust gas treatment device according to any one of claims 1 to 3, characterized in that: The catalyst unit (3) is provided with a front NOx filter located at the inlet end of the catalyst unit (3). x The sensor (31) and the post-NOx at the outlet end of the catalyst unit (3) x Sensor (32).

9. A control method for a hydrogen fuel engine exhaust treatment device, characterized in that: The control method comprises the following steps: after the hydrogen fuel engine is started, the tail gas of the hydrogen fuel engine is input into a catalyst unit (3) for NO x After the reduction conversion, the gas-liquid separation is carried out in the gas-water separation unit (4) to obtain a gas separation product. The gas separation product is subjected to the gas-gas separation unit (5) to remove N2 to obtain a non-N2 gas. The non-N2 gas is input into the ammonia storage unit (6) to carry out an NH3 synthesis reaction. During this process, the NO in the catalyst unit (3) is obtained. x Mass, calculate NO x The mass of NH3 required for complete conversion m NH3 , using the ammonia storage unit (6) to input a mass of m into the catalyst unit (3) NH3 of NH3.

10. The control method according to claim 9, characterized in that: The ammonia storage unit (6) is used to input a mass of m into the catalyst unit (3). NH3 The NH3 process adopts the following control process: Get the real-time NH3 mass m in the ammonia storage unit (6) NH31 , determine m NH31 Is it greater than m? NH3 , if m NH31 Greater than m NH3 , then directly input a mass of m into the catalyst unit (3) through the ammonia storage unit (6) NH3 of NH3; if m NH31 Less than m NH3 , then calculate the NH3 mass ε that needs to be supplemented in the ammonia storage unit (6) NH3 =m NH3 -m NH31 And the composite mass is ε NH3 The mass of H2 required to produce NH3 m H21 , inputting a mass of m into the ammonia storage unit (6) H21 The H2 undergoes NH3 synthesis reaction and inputs a mass of m into the catalyst unit (3) through the ammonia storage unit (6). NH3 of NH3.

11. The control method according to claim 10, characterized in that: Obtain the real-time H2 mass m in the gas-gas separation unit (5) H20 , determine m H20 Is it greater than m? H21 , if m H20 Greater than m H21 , then directly input the ammonia with a mass of m into the ammonia storage unit (6) through the gas separation unit (5) H21 H2; if m H20 Less than m H21 , then calculate the H2 mass ε that needs to be replenished in the ammonia storage unit (6) H2 =m H21 -m H20 , a mass of m is input to the ammonia storage unit (6) through the gas separation unit (5) H20 At the same time, an external source device is used to input ammonia storage unit (6) with a mass of ε H2 H2.

12. The control method according to any one of claims 9 to 11, characterized in that: Obtain NO at the inlet end of the catalyst unit (3) x Mass m Nox0 and NO at the outlet of the catalyst unit (3) x Mass m NOx1 , calculate the NO in the catalyst unit (3) x Reduction-converted NO x Conversion efficiency η = 1-m NOx1 / m NOx0 , determine whether η is greater than the set target value a, if η is greater than a, then m NH3 The NO in the exhaust gas of the hydrogen fuel engine input into the catalyst unit (3) x The mass of NH3 required for complete conversion m NH30 If η is less than a, the calculation requires a secondary conversion of NO x Mass m NOx2 =m NOx1 -(1-a)m NOx0 and mass is m NOx2 NO x The mass of NH3 required for complete conversion m NH32 , m NH3 =m NH30 +m NH32 .

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