Exhaust aftertreatment device of hydrogen ammonia fuel engine

Abstract

The utility model discloses a hydrogen ammonia fuel engine exhaust aftertreatment device which comprises a first-stage catalysis part, a second-stage catalysis part and a third-stage catalysis part which are sequentially communicated, a first heater is arranged between the first-stage catalysis part and the second-stage catalysis part, a second heater is arranged between the second-stage catalysis part and the third-stage catalysis part, and a third heater is arranged between the third-stage catalysis part and the third-stage catalysis part. And gas sequentially flows through the first-stage catalysis part, the second-stage catalysis part and the third-stage catalysis part. H2, NH3 and NOX in waste gas can be effectively removed by arranging the first-stage catalysis part, the second-stage catalysis part and the third-stage catalysis part, meanwhile, the first heater and the second heater are arranged between the first-stage catalysis part and the second-stage catalysis part and between the second-stage catalysis part and the third-stage catalysis part respectively to heat gas, the reaction temperature requirement is met, and the reaction efficiency is improved. Meanwhile, the heater I and the heater II can ensure that the gas temperature is uniform, and liquid in the heater I and the heater II can be effectively removed after the reaction is finished.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of waste gas treatment, more specifically, to a hydrogen ammonia fuel engine exhaust aftertreatment device. BACKGROUND

[0002] In order to follow up the state emission requirement policy, reduce carbon dioxide emission, the traditional fossil fuel engine gradually changes, and the research of replacing fossil fuel with carbon-free fuel is also mature. Hydrogen has low ignition energy, strong lean combustion ability, wide combustion range and fast flame propagation speed, which is an ideal carbon-free fuel. However, hydrogen is low in density, flammable and explosive, and is not convenient to store and transport. Ammonia has high minimum ignition energy and slow flame propagation speed, and is not suitable for use as a fuel alone in a ship engine. However, ammonia has high volumetric energy density and is not prone to explosion, and can be converted into urea, which is convenient to store and transport. Combining the advantages of both, hydrogen and ammonia can be mixed in a certain proportion as fuel for a ship engine.

[0003] The CO2 emission of hydrogen ammonia fuel engine exhaust is zero, the HC and CO emissions are close to zero, but H2, NH3 and high NO X emissions will be generated. The existing device can respectively realize the treatment of H2, NH3 and NO X , but the equipment structure is complex, and because the contents of H2, NH3 and NO X are different, there is often the problem of incomplete NO X treatment. At the same time, compared with traditional fuel engines, the exhaust temperature of hydrogen ammonia fuel engines is lower, and in order to make the exhaust treatment catalyst work efficiently, the exhaust temperature needs to be increased, otherwise there is a problem of insufficient reaction, and the water vapor generated by the end of heating decomposition may condense in the heater, which is easy to cause corrosion in the interior of the heater. UTILITY MODEL CONTENTS

[0004] The utility model aims at providing a hydrogen ammonia fuel engine exhaust aftertreatment device to solve the technical problems existing in the above background technology.

[0005] The utility model technical scheme provides a hydrogen ammonia fuel engine exhaust aftertreatment device, which comprises a first-stage catalytic part, a second-stage catalytic part and a third-stage catalytic part which are sequentially and communicatively arranged, a heater one is arranged between the first-stage catalytic part and the second-stage catalytic part, a heater two is arranged between the second-stage catalytic part and the third-stage catalytic part, and gas sequentially flows through the first-stage catalytic part, the second-stage catalytic part and the third-stage catalytic part;

[0006] The heater one and the heater two both comprise a heating bin, a heating element located in the heating bin and an air inlet assembly and an air outlet assembly connected with the heating bin and used for dispersing gas, and a cleaning pipe one and a cleaning pipe two are sequentially and externally connected to the air inlet assembly and the air outlet assembly.

[0007] In a preferred embodiment, the primary catalytic part is provided with a primary catalytic module for treating NO X and H2, and the surface of the primary catalytic module is coated with a noble metal catalyst coating one;

[0008] The secondary catalytic part is provided with a secondary catalytic module for treating NO X and NH3, and the surface of the secondary catalytic module is coated with a vanadium-based catalyst coating;

[0009] The tertiary catalytic part is provided with a tertiary catalytic module for treating NH3, and the surface of the tertiary catalytic module is coated with a noble metal catalyst coating two.

[0010] In a preferred embodiment, the primary catalytic part, the secondary catalytic part and the tertiary catalytic part are all provided with a gas supplement port.

[0011] In a preferred embodiment, a plurality of temperature sensors, nitrogen oxide sensors and ammonia sensors are included.

[0012] In a preferred embodiment, the heating element is an electric heating element.

[0013] In a preferred embodiment, the gas inlet assembly includes an annular gas inlet pipe, a plurality of gas inlet branch pipes equidistantly arranged on the annular gas inlet pipe, the gas inlet branch pipes being in communication with the heating chamber, and a gas inlet port being arranged on the annular gas inlet pipe.

[0014] In a preferred embodiment, the gas outlet assembly includes a plurality of gas outlet pipes distributed at the gas outlet end of the heating chamber and a uniform gas chamber in communication with the output ends of the gas outlet pipes, and a gas outlet port being arranged on the uniform gas chamber.

[0015] The beneficial effects of the technical scheme of the utility model are as follows:

[0016] By arranging the primary catalytic part, the secondary catalytic part and the tertiary catalytic part, the H2, NH3 and NO X in the exhaust gas can be effectively removed, and the heaters one and two arranged between the primary catalytic part and the secondary catalytic part and between the secondary catalytic part and the tertiary catalytic part can heat the gas to meet the reaction temperature requirement, and the heaters one and two can ensure that the gas temperature is uniform, and after the reaction is completed, the heaters one and two can effectively remove the liquid inside. BRIEF DESCRIPTION OF DRAWINGS

[0017] Fig. 1 is a schematic diagram of the overall structure of the utility model,

[0018] Fig. 2 is a schematic diagram of the overall structure of the heater of the utility model,

[0019] Fig. 3 It is the internal structure schematic view of the heater of the utility model.

[0020] Reference signs: 1 primary catalytic part, 2 secondary catalytic part, 3 tertiary catalytic part, 4 heater one, 5 heater two, 6 primary catalytic module, 7 secondary catalytic module, 8 tertiary catalytic module, 9 air supplementing port, 10 heating bin, 11 heating element, 12 annular air inlet pipe, 13 air inlet branch pipe, 14 air inlet, 15 air outlet pipe, 16 air uniformizing bin, 17 air outlet, 18 cleaning pipe one, 19 cleaning pipe two, 20 temperature sensor, 21 nitrogen oxide sensor, 22 ammonia sensor. DETAILED DESCRIPTION

[0021] The utility model will be further explained in detail in combination with the drawings and specific embodiments. The embodiments of the utility model are given for the convenience of example and description, and are not exhaustive or limit the utility model to the disclosed form. Many modifications and changes are obvious to those skilled in the art. The embodiments are selected and described to better illustrate the principles and practical application of the utility model, and to enable those skilled in the art to understand the utility model so as to design various embodiments with various modifications suitable for specific purposes.

[0022] As Figs. 1-3 The utility model technical scheme provides a kind of hydrogen ammonia fuel engine exhaust aftertreatment device, including the sequentially intercommunicating setting primary catalytic part 1, secondary catalytic part 2 and tertiary catalytic part 3, the primary catalytic part 1 and the secondary catalytic part 2 between being provided with heater one 4, the secondary catalytic part 2 and the tertiary catalytic part 3 between being provided with heater two 5, gas sequentially flows through primary catalytic part 1, secondary catalytic part 2 and tertiary catalytic part 3.

[0023] Among them, the primary catalytic part 1 is provided with the primary catalytic module 6 of processing NO X And H2, the surface of the primary catalytic module 6 is coated with noble metal catalyst coating one;The secondary catalytic part 2 is provided with the secondary catalytic module 7 group of processing NO X And NH3, the surface of the secondary catalytic module 7 group is coated with vanadium-based catalyst coating;The tertiary catalytic part 3 is coated with the tertiary catalytic module group 8 of processing NH3, the surface of the tertiary catalytic module group 8 is coated with noble metal catalyst coating two. Noble metal catalyst coating one and noble metal catalyst coating two are selected according to processing requirements, such as palladium-platinum alloy, platinum-rhodium alloy etc.

[0024] The scheme also includes several temperature sensors 20, nitrogen oxide sensors 21 and ammonia sensors 22. Primary catalytic part 1, secondary catalytic part 2 and tertiary catalytic part 3 are all provided with air supplementing port 9.

[0025] In the process of exhaust treatment of hydrogen-ammonia fuel engine, the treatment of exhaust gas is based on the surface coating of catalyst module in each catalytic part, which is as follows:

[0026] ①Treatment of H2 in the exhaust gas of hydrogen-ammonia fuel engine

[0027] In the first catalytic part 1, part of NOx in the exhaust gas reacts with all H2 to generate N2; the hydrogen sensor first detects the H2 content in the exhaust gas, if the H2 content is lower than the required H2 content for the normal operation of the first catalytic part 1, the controller controls the hydrogen nozzle to supplement, and in the first catalytic part 1, part of NOx in the exhaust gas reacts with all H2 to generate N2;

[0028] The main reaction occurring in the first catalytic part 1 is: 2NO + 2H2→ N2 + 2H2O;

[0029] ②Treatment of NOx and NH3 in the exhaust gas from the first catalytic part 1

[0030] In the second catalytic part 2, NOx in the exhaust gas reacts with NH3 by redox reaction; the ammonia sensor 22 first detects the NH3 content in the exhaust gas, if the NH3 content is lower than the required NH3 content for the normal operation of the second catalytic part 2, the controller controls the ammonia nozzle to supplement; the temperature sensor 20 detects the temperature of the exhaust gas from the first catalytic part 1, and the controller controls the heater one 4 to heat the gas to ensure the required gas temperature for the normal operation of the second catalytic part 2; in the second catalytic part 2, NOx in the exhaust gas reacts with NH3 by redox reaction. The main reaction occurring in the second catalytic part 2 is:

[0031] 4NO + 4NH3 + O2→ 4N2 + 6H2O

[0032] 2NO2 + 4NH3 + O2→ 3N2 + 6H2O;

[0033] ③Treatment of excess NH3 in the exhaust gas from the second catalytic part 2

[0034] In the third catalytic part 3, excess NH3 in the exhaust gas reacts; the exhaust temperature sensor 20 detects the temperature of the exhaust gas from the second catalytic part 2, and the controller controls the heater two 5 to heat the gas to ensure the required gas temperature for the normal operation of the third catalytic part 3; in the third catalytic part 3, excess NH3 in the exhaust gas reacts; the main reaction occurring in the third catalytic part 3 is: 4NH3 + 3O2→ 2N2 + 6H2O;

[0035] ④Detection of NOx and NH3 in the exhaust gas from the third catalytic part 3

[0036] If the NOx and NH3 are detected to be lower than or equal to the target emission value, tail gas emission is carried out, and NH3 is supplemented according to the original supplement amount; if the NOx and NH3 are detected to be higher than the target emission value, the controller controls the ammonia nozzle to increase the NH3 supplement amount, and the controller controls the air supplement opening 9 to supplement O2. The first-stage catalytic part 1 can remove all H2 in the hydrogen-ammonia fuel engine exhaust gas, avoid the influence of H2 on the performance of the subsequent treatment device, and increase the accuracy of the sensor.

[0037] When the above reaction is carried out, the heater one 4 and the heater two 5 can realize accurate temperature control, and at the same time ensure that the gas temperature is uniform, avoiding the case that the local temperature is too high. The heater one 4 and the heater two 5 both include a heating bin 10, a heating element 11 located in the heating bin 10, and an air inlet assembly and an air outlet assembly connected with the heating bin 10 and used for dispersing gas.

[0038] The heating element 11 is an electric heating element, which adopts a heating wire structure and realizes temperature control by controlling voltage and the like. The air inlet assembly includes an annular air inlet pipe 12, a plurality of air inlet branch pipes 13 equidistantly arranged on the annular air inlet pipe 12, the air inlet branch pipes 13 being in communication with the heating bin 10, and an air inlet 14 arranged on the annular air inlet pipe 12. The air outlet assembly includes a plurality of air outlet pipes 15 distributed at the air outlet end of the heating bin 10 and an air uniformizing bin 16 in communication with the output ends of the air outlet pipes 15, and an air outlet 17 arranged on the air uniformizing bin 16.

[0039] When air is inhaled, the gas first enters the annular air inlet pipe 12, then is dispersed into the heating bin 10 through the air inlet branch pipes 13 on the annular air inlet pipe 12, is heated by the heating element 11 in the heating bin 10, and is then discharged through the air outlet assembly. The gas is dispersed into the air uniformizing bin 16 through the air outlet pipes 15, then is mixed in the air uniformizing bin 16, so that the gas temperatures in different regions are close to each other, and then enters the corresponding catalytic part through the air outlet 17.

[0040] At the same time, the air inlet assembly and the air outlet assembly are sequentially connected with a cleaning pipe one 18 and a cleaning pipe two 19. After the treatment is completed and the heating element 11 is cooled, condensate will be generated in the heating bin 10. By ventilating the cleaning pipe one 18 and exhausting the cleaning pipe two 19, the inside of the heating bin 10 can be dried.

[0041] Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art and related fields without creative labor should belong to the protection scope of the present application. The structures, devices and operation methods not specifically described and explained in the present application, such as without special description and limitation, are implemented according to the conventional means in the art.

Claims

1. An exhaust aftertreatment device for a hydrogen-ammonia fuel engine, characterized by: The device comprises a first-stage catalytic part, a second-stage catalytic part and a third-stage catalytic part which are sequentially connected, a heater one is arranged between the first-stage catalytic part and the second-stage catalytic part, a heater two is arranged between the second-stage catalytic part and the third-stage catalytic part, and gas flows through the first-stage catalytic part, the second-stage catalytic part and the third-stage catalytic part in sequence; The heater one and the heater two each comprise a heating bin, a heating element arranged in the heating bin, and an air inlet assembly and an air outlet assembly which are connected with the heating bin and used for dispersing gas, and a cleaning pipe one and a cleaning pipe two are sequentially connected with the air inlet assembly and the air outlet assembly.

2. A hydrogen-ammonia fuel engine exhaust aftertreatment device according to claim 1, characterized in that: The primary catalytic part is provided with a primary catalytic module for treating NO X and H2, and the surface of the primary catalytic module is coated with a noble metal catalyst coating layer one. The secondary catalytic part is provided with a secondary catalytic module for treating NO X and NH3, and the surface of the secondary catalytic module is coated with a vanadium-based catalyst coating. A third-stage catalytic module for treating NH3 is coated on a carrier in the third-stage catalytic part, and a noble metal catalyst coating two is coated on a surface of the third-stage catalytic module.

3. A hydrogen / ammonia fuel engine exhaust after treatment device as in claim 1, wherein: The first-stage catalytic part, the second-stage catalytic part and the third-stage catalytic part are each provided with a gas supplementing port.

4. A hydrogen / ammonia fuel engine exhaust after treatment device as in claim 1, wherein: The device further comprises a plurality of temperature sensors, nitrogen oxide sensors and ammonia sensors.

5. A hydrogen / ammonia fuel engine exhaust after treatment device as set forth in claim 1 wherein: The heating element is an electric heating element.

6. A hydrogen / ammonia fuel engine exhaust after treatment device as set forth in claim 1 wherein: The air inlet assembly comprises a ring-shaped air inlet pipe, a plurality of air inlet branch pipes which are equidistantly arranged on the ring-shaped air inlet pipe, the air inlet branch pipes are communicated with the heating bin, and an air inlet port is arranged on the ring-shaped air inlet pipe.

7. A hydrogen / ammonia fuel engine exhaust after treatment device as set forth in claim 1 wherein: The air outlet assembly comprises a plurality of air outlet pipes which are distributed on an air outlet end of the heating bin and a uniform air bin which is communicated with output ends of the air outlet pipes, and an air outlet port is arranged on the uniform air bin.

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