Post-treatment device of hydrogen internal combustion engine

Abstract

The aftertreatment device comprises a selective reduction catalyst and an ammonia gas ejector, an air inlet of the selective reduction catalyst is connected with an air inlet pipeline, an air outlet of the selective reduction catalyst is connected with an exhaust pipeline, and the air inlet pipeline is connected with an exhaust pipe of the hydrogen internal combustion engine; the selective reduction catalytic converter comprises a first catalytic converter and a second catalytic converter; a VWT catalyst is arranged in the first catalytic converter and is close to one end of the gas inlet pipeline; a copper-based catalyst is arranged in the second catalyst and is close to one end of the gas outlet pipeline; and the ammonia gas ejector is mounted on the gas inlet pipeline. Compared with the prior art, the device has the advantages that the ammonia gas injector injects a certain amount of ammonia gas, so that the reduction rate of NOx in tail gas of the hydrogen internal combustion engine is improved; the tail gas firstly passes through the first catalytic converter to treat most NOx, and then passes through the second catalytic converter to remove residual NOx and reduce generation of N2O, so that continuous and efficient emission reduction of nitrogen oxides in the hydrogen internal combustion engine is guaranteed, and generation of harmful products is avoided.

Description

Technical Field

[0001] This utility model relates to exhaust gas treatment, and more particularly to an after-treatment device for a hydrogen internal combustion engine. Background Technology

[0002] Hydrogen-powered engines are one of the hot topics in hydrogen energy utilization. However, the extremely high speed of hydrogen combustion leads to a sharp increase in cylinder pressure and temperature, resulting in the emission of large amounts of nitrogen oxides that harm the environment. Therefore, after-treatment devices need to be installed in hydrogen internal combustion engine systems.

[0003] Currently, exhaust aftertreatment technologies for hydrogen internal combustion engines mainly focus on NO. x The treatment primarily utilizes selective reduction catalysis (SCR) systems. Traditional SCR catalysts mainly include VWT and Cu-based catalysts. While Cu-based catalysts exhibit superior catalytic performance, they struggle with large amounts of NO. x The reaction produces harmful byproduct N2O, while the VWT catalyst, although not as catalytically effective as the Cu-based catalyst, produces no harmful byproducts.

[0004] Application publication number CN115506874A discloses a two-stage active-passive SCR coupled aftertreatment device and its control method for hydrogen fuel cell internal combustion engines. This device performs secondary treatment of nitrogen oxides in the exhaust gas by coupling a two-stage SCR system, thereby achieving the removal of NO from the exhaust gas of hydrogen internal combustion engines. x Continuous and efficient emission reduction to solve the NOx problem of hydrogen internal combustion engines x The problem is high emissions. However, this method only considers NO in the exhaust gas. x While it achieves efficient removal of nitrogen dioxide (N2O), it does not control the potentially harmful byproduct. Furthermore, due to the installation of two aftertreatment units, the entire system occupies a significant amount of space. Therefore, it is only suitable for heavy-duty engines with low space utilization requirements and cannot meet the NO2O emission standards of small, lightweight hydrogen engines. x Emission requirements limit the scope of application.

[0005] Therefore, designing a compact aftertreatment device for a hydrogen internal combustion engine is a technical problem that needs to be solved. Utility Model Content

[0006] The purpose of this invention is to overcome the shortcomings of the existing technology, which occupies a large space, and to provide an after-treatment device for a hydrogen internal combustion engine.

[0007] The objective of this utility model can be achieved through the following technical solutions:

[0008] According to one aspect of the present invention, an aftertreatment device for a hydrogen internal combustion engine is provided, comprising a selective reduction catalyst and an ammonia injector. The inlet of the selective reduction catalyst is connected to an intake pipe, and the outlet is connected to an exhaust pipe. The intake pipe is connected to the exhaust pipe of the hydrogen internal combustion engine. The selective reduction catalyst includes a first catalyst and a second catalyst. The first catalyst contains a VWT catalyst and is located near one end of the intake pipe. The second catalyst contains a copper-based catalyst and is located near one end of the outlet pipe. The ammonia injector is installed on the intake pipe, and the outlet of the ammonia injector is located inside the intake pipe.

[0009] As a preferred technical solution, the device also includes an electronic control unit and a temperature sensor, wherein the temperature sensor is installed on the air intake pipe and is communicatively connected to the electronic control unit.

[0010] As a preferred technical solution, the device also includes an upstream nitrogen oxide sensor, which is installed on the intake pipe and communicates with the electronic control unit.

[0011] As a preferred technical solution, the device also includes a heater, which is installed in the air intake pipe and is communicatively connected to the electronic control unit.

[0012] As a preferred technical solution, the heater is located between the temperature sensor and the selective reduction catalyst.

[0013] As a preferred technical solution, the outlet of the ammonia injector is located between the heater and the selective reduction catalyst.

[0014] As a preferred technical solution, the device also includes a downstream nitrogen oxide sensor, which is installed on the exhaust pipe and communicates with the electronic control unit.

[0015] As a preferred technical solution, the device also includes an alarm, which is connected to the electronic control unit.

[0016] As a preferred technical solution, the ammonia injector is communicatively connected to the electronic control unit.

[0017] As a preferred technical solution, the ammonia injector is connected to the urea storage tank.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] 1) This utility model's ammonia injector injects a certain amount of ammonia gas based on concentration and temperature information obtained from sensors, in order to increase the NO content in the exhaust gas of a hydrogen internal combustion engine. x The reduction rate; then the exhaust gas first passes through the first catalytic converter, which removes most of the NO. xAfter treatment, the exhaust gas then passes through a second catalytic converter to remove any remaining NO. x It reduces the generation of N2O; it can ensure continuous and efficient emission reduction of nitrogen oxides in hydrogen internal combustion engines, while avoiding the generation of N2O, a potentially harmful product, during the reduction catalysis process; the device has a small footprint and low space requirements, and can be applied to different types of hydrogen engines, such as heavy-duty and light-duty models.

[0020] 2) The upstream nitrogen oxide sensor and temperature sensor of this utility model respectively detect NO in the exhaust gas. x Concentration and temperature information are collected and monitored in real time. When the measured temperature is lower than the minimum catalytic temperature or the measured NO... x When the concentration is high, the heater is activated to heat the exhaust gas to improve the aftertreatment catalytic efficiency. The heater is located between the temperature sensor and the selective reduction catalyst to ensure that the exhaust gas with a temperature that is too low as measured by the temperature sensor is heated by the heater before entering the selective reduction catalyst.

[0021] 3) The downstream nitrogen oxide sensor of this invention monitors the concentration of the treated exhaust gas, based on NO... x The concentration dynamically adjusts the injection volume of the ammonia injector; ammonia is supplied through urea in the urea storage tank, which reduces the storage volume; when the injection volume of the ammonia injector reaches its maximum value but still fails to meet emission requirements or when other malfunctions occur, the alarm will sound. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the overall structure of an aftertreatment device for a hydrogen internal combustion engine according to the present invention.

[0023] Figure 2 This is a schematic diagram of the selective reduction catalyst of this utility model;

[0024] The numbers in the diagram are as follows:

[0025] 1. Intake pipe; 2. Selective reduction catalyst; 21. First catalyst; 22. Second catalyst; 3. Exhaust pipe; 4. Upstream nitrogen oxide sensor; 5. Temperature sensor; 6. Downstream nitrogen oxide sensor; 7. Ammonia injector; 8. Heater; 9. Electronic control unit. Detailed Implementation

[0026] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some, not all, of the embodiments of the present utility model. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present utility model.

[0027] like Figure 1 As shown, this utility model provides an aftertreatment device for a hydrogen internal combustion engine, including a selective reduction catalyst 2, an upstream nitrogen oxide sensor 4, a temperature sensor 5, a downstream nitrogen oxide sensor 6, an ammonia injector 7, a heater 8, an alarm, and an electronic control unit 9. The inlet of the selective reduction catalyst 2 is connected to an intake pipe 1, and the outlet is connected to an exhaust pipe 3. The intake pipe 1 is connected to the exhaust pipe of the hydrogen internal combustion engine.

[0028] like Figure 2 As shown, the selective reduction catalyst 2 includes a first catalyst 21 and a second catalyst 22. The first catalyst 21 contains a VWT catalyst and is located near one end of the intake pipe 1; the second catalyst 22 contains a copper-based catalyst and is located near one end of the exhaust pipe. The VWT catalyst is V2O5-WO3-TiO2, and the copper-based catalyst is Cu-SSZ-13. The exhaust gas first passes through the first catalyst 21, which removes most of the NO. x After treatment, the exhaust gas then passes through the second catalytic converter 22 to remove any remaining NO. x And reduce the generation of N2O.

[0029] An upstream nitrogen oxide sensor 4, a temperature sensor 5, a heater 8, and an ammonia injector 7 are sequentially installed on the intake duct 1, all of which are communicatively connected to the electronic control unit 9. The upstream nitrogen oxide sensor 4 detects the concentration of nitrogen oxides in the intake air, the temperature sensor 5 detects the intake air temperature, the heater 8 heats the lower-temperature exhaust gas, and the ammonia injector 7, located inside the intake duct 1, quantitatively injects ammonia for catalysis based on information collected by the upstream nitrogen oxide sensor 4, the downstream nitrogen oxide sensor 6, and the temperature sensor 5. The heater 8 is located between the temperature sensor 5 and the selective reduction catalyst 2, ensuring that exhaust gas with a temperature too low as measured by the temperature sensor 5 is heated by the heater 8 before entering the selective reduction catalyst 2.

[0030] Ammonia injector 7 is connected to a urea storage tank, which provides ammonia for catalysis. Downstream nitrogen oxide sensor 6 is installed on the outlet pipe to detect the concentration of nitrogen oxides in the exhaust gas. An alarm is connected to the electronic control unit 9.

[0031] When the hydrogen internal combustion engine starts, the generated exhaust gas enters the intake pipe 1. The upstream nitrogen oxide sensor 4 and temperature sensor 5 detect the NO in the exhaust gas. x Concentration α1 and temperature T1 are collected and monitored in real time. When the monitored T1 is lower than the set minimum catalytic temperature T0, heater 8 is activated to heat the exhaust gas to improve the post-treatment catalytic efficiency. Ammonia injector 7 injects a certain amount of NH3 according to the concentration and temperature information obtained by the sensor, and the exhaust gas is denitrified under the action of selective reduction catalyst 2. After the exhaust gas passes through the first catalyst 21, most of the NO... xIt is processed and then reacts with a second catalyst 22, which has better catalytic performance, to remove the remaining NO. x This reduces N2O generation. The post-treated exhaust gas is discharged through the outlet pipe, and the concentration α2 of the treated exhaust gas is monitored by the downstream nitrogen oxide sensor 6. The collected concentration data is fed back to the electronic control unit 9, which dynamically adjusts the injection rate of the ammonia injector 7. If the nitrogen oxide concentration α2 meets the emission regulation requirement of nitrogen oxide concentration α0, the original injection rate is maintained; if the nitrogen oxide concentration α2 is higher than the emission regulation requirement of nitrogen oxide concentration α0, the electronic control unit 9 will correct the injection rate of the injector, appropriately increasing the injection rate to ensure higher NO levels. x Reduction rate. If the exhaust gas still fails to meet emission requirements even when the injection rate reaches the set maximum rate, especially when the NO2 in the exhaust gas before and after catalysis is detected by the upstream and downstream NOx sensors 6, x When the concentration difference is lower than the preset concentration difference threshold, the electronic control unit 9 determines that there is a fault in the aftertreatment device, the alarm sounds, and the aftertreatment device should be repaired or replaced in time to ensure that the emissions of the hydrogen internal combustion engine meet the exhaust emission regulations.

[0032] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this utility model, and these modifications or substitutions should all be covered within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.

Claims

1. An aftertreatment device for a hydrogen internal combustion engine, characterized by, The device comprises a selective reduction catalyst (2) and an ammonia injector (7), the gas inlet of the selective reduction catalyst (2) is connected with the gas inlet pipe (1), the gas outlet is connected with the exhaust pipe (3), the gas inlet pipe (1) is connected with the exhaust pipe of the hydrogen internal combustion engine; the selective reduction catalyst (2) comprises a first catalyst (21) and a second catalyst (22), the first catalyst (21) has a VWT catalyst therein and is close to one end of the gas inlet pipe (1); the second catalyst (22) has a copper-based catalyst therein and is close to one end of the exhaust pipe; the ammonia injector (7) is installed on the gas inlet pipe (1), and the injection outlet of the ammonia injector (7) is located in the gas inlet pipe (1).

2. An aftertreatment device for a hydrogen internal combustion engine according to claim 1, characterized by The device further comprises an electric control unit (9) and a temperature sensor (5), the temperature sensor (5) is installed on the gas inlet pipe (1) and is connected with the electric control unit (9) in communication.

3. A post-processing device for a hydrogen internal combustion engine according to claim 2, characterized by The device further comprises an upstream nitrogen oxide sensor (4), which is installed on the gas inlet pipe (1) and is connected with the electric control unit (9) in communication.

4. The aftertreatment device of claim 2, wherein the aftertreatment device is a diesel particulate filter. The device further comprises a heater (8), which is installed in the gas inlet pipe (1) and is connected with the electric control unit (9) in communication.

5. A post-processing device for a hydrogen internal combustion engine according to claim 4, characterized by The heater (8) is located between the temperature sensor (5) and the selective reduction catalyst (2).

6. A post-processing device for a hydrogen internal combustion engine according to claim 4, characterized by The injection outlet of the ammonia injector (7) is located between the heater (8) and the selective reduction catalyst (2).

7. A post-processing device for a hydrogen internal combustion engine according to claim 2, characterized by The device further comprises a downstream nitrogen oxide sensor (6), which is installed on the exhaust pipe (3) and is connected with the electric control unit (9) in communication.

8. A post-processing device for a hydrogen internal combustion engine according to claim 7, characterized by The device further comprises an alarm, which is connected with the electric control unit (9).

9. The aftertreatment device of claim 2, wherein, The ammonia injector (7) is connected with the electric control unit (9) in communication.

10. The aftertreatment device of claim 1, wherein, The ammonia injector (7) is connected with a urea storage tank.

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