Working method of ammonia fuel engine emission integrated purification aftertreatment device

Abstract

The application provides a working method of an ammonia fuel engine emission integrated purification aftertreatment device, which comprises an ammonia storage releaser, an ammonia storage and release catalyst, a mixer, a selective catalytic reduction device and an ammonia oxidation catalyst; an ammonia fuel engine emission port is sequentially connected with the ammonia storage releaser, the mixer, the selective catalytic reduction device and the ammonia oxidation catalyst; and the ammonia storage releaser is internally provided with the ammonia storage and release catalyst. The ammonia fuel engine unburned ammonia can be flexibly stored and released through the ammonia storage releaser, the proportion difference of the unburned ammonia and NOx emissions of the ammonia fuel engine under different working conditions can be coped with, the optimal reducing agent ammonia and NOx proportion before the selective catalytic reduction device can be ensured at all times, the unburned ammonia and NOx in the ammonia fuel engine tail gas can be integrated purified, and the additional reducing agent storage, supply and injection system can be omitted.

Description

TECHNICAL FIELD

[0001] The present application relates to an ammonia fuel engine exhaust treatment device, in particular to a working method of an ammonia fuel engine emission integrated purification aftertreatment device. BACKGROUND

[0002] Traditional diesel engines use selective catalytic reduction (SCR) to treat NOx in exhaust gas, and urea or ammonia is injected before the front end of the SCR, and an ammonia oxidation catalyst (ASC) is installed at the rear end of the SCR to oxidize the excess escaped ammonia. Due to the poor combustion characteristics of ammonia, ammonia fuel engine exhaust gas also contains unburned ammonia in addition to NOx, which can act as a reducing agent for SCR reactions, thereby eliminating the need for additional reducing agent supply and injection systems. Unfortunately, the prior art solution fails to optimize the design of the aftertreatment device for the characteristics of ammonia fuel engine exhaust gas, and cannot cope with the problem of large changes in the composition of unburned ammonia and NOx in the exhaust gas under different operating conditions of the ammonia fuel engine. At the same time, the solution still continues to inject additional reducing agents, and fails to fully utilize the unburned ammonia in the exhaust gas of the ammonia fuel engine.

[0003] For example, patent document CN114856764A discloses an exhaust treatment system for an ammonia fuel engine, an engine and a ship, which can be applied to the field of exhaust treatment technology. The system of the present application removes water from the exhaust gas emitted by the engine through a first water removal device, reacts the water-removed exhaust gas with hydrogen through a nitrogen oxide trap to generate a small amount of ammonia gas, collects part of the exhaust gas output by the nitrogen oxide trap through a pipeline provided to utilize the waste heat of the exhaust gas to provide heat to the ammonia gas synthesis device provided, so that the ammonia gas synthesis device synthesizes ammonia gas, outputs the remaining exhaust gas and ammonia gas to the heat exchanger provided, and then utilizes the denitrification device provided to reduce the exhaust gas and ammonia gas into nitrogen and water, separates the non-condensable gas and collects the ammonia gas through the liquid nitrogen heat exchanger provided, and then removes nitrogen and water through the water tank and the second water removal device, and then separates nitrogen and oxygen through the nitrogen separation device, thereby realizing the collection of ammonia gas and the recycling of exhaust gas. Patent document CN217206623U discloses a post-treatment device for hydrogen-ammonia fuel engine exhaust, which comprises an exhaust catalytic device and an ammonia gas supply device. The exhaust catalytic device is used to convert ammonia gas NH3 and nitrogen oxide NOX in the exhaust gas, and the ammonia gas supply device is used to supply ammonia gas NH3 to the exhaust catalytic device. The exhaust catalytic device comprises a first SCR catalyst, a first exhaust pipe, a second SCR catalyst, a second exhaust pipe and an ammonia escape catalyst ASC connected in sequence. The inlet of the first SCR catalyst is connected with the exhaust pipe outlet of the hydrogen-ammonia fuel engine, and the end of the ammonia gas supply device is installed on the first exhaust pipe. The existing exhaust treatment device has a complex structure, requires additional supply of reducing agent ammonia, and fails to achieve integrated purification. SUMMARY

[0004] In view of the defects in the prior art, the purpose of the present application is to provide a working method of an ammonia fuel engine emission integrated purification aftertreatment device.

[0005] According to the present application, a working method of an ammonia fuel engine emission integrated purification aftertreatment device is provided, which comprises: an ammonia storage releaser, an ammonia storage and release catalyst, a mixer, a selective catalytic reducer, and an ammonia oxidation catalyst.

[0006] The ammonia storage releaser, the mixer, the selective catalytic reducer, and the ammonia oxidation catalyst are sequentially connected in the order of the ammonia storage releaser, the mixer, the selective catalytic reducer, and the ammonia oxidation catalyst after the ammonia fuel engine emission port.

[0007] The ammonia storage and release catalyst is arranged inside the ammonia storage releaser.

[0008] The working method of the ammonia fuel engine emission integrated purification aftertreatment device further comprises the following steps:

[0009] Step S1, the first NOx sensor and the first ammonia sensor measure the NOx and unburned ammonia content in the ammonia fuel engine exhaust gas and feed back to the controller.

[0010] Step S2, when the unburned ammonia in the ammonia fuel engine exhaust gas is excessive relative to the NOx, the controller controls the ammonia storage releaser to work, and the ammonia storage releaser stores the excessive ammonia in the ammonia storage mode.

[0011] At the same time, the controller collects the second NOx sensor and the second ammonia sensor data to ensure that the appropriate ammonia and NOx ratio before the selective catalytic reducer is used for the SCR reaction, realizing the integrated purification of unburned ammonia and NOx.

[0012] Step S3, when the NOx in the ammonia fuel engine exhaust gas is excessive relative to the unburned ammonia, the controller controls the ammonia storage releaser to work in the ammonia release mode to release the reducing agent ammonia for the SCR reaction in the selective catalytic reducer.

[0013] At the same time, the controller collects the second NOx sensor and the second ammonia sensor data to ensure that the appropriate ammonia and NOx ratio before the selective catalytic reducer is used for the SCR reaction, realizing the integrated purification of unburned ammonia and NOx.

[0014] Step S4, according to the measurement values of the first NOx sensor and the first ammonia sensor, combined with the ammonia fuel engine exhaust gas flow, the ammonia storage amount in the ammonia storage releaser is calculated in real time, and when the ammonia storage is full, the excessive ammonia is released to the ammonia oxidation catalyst to be converted into environmentally friendly nitrogen.

[0015] Step S5, the third NOx sensor and the third ammonia sensor confirm whether the NOx and unburned ammonia emissions after the ammonia oxidation catalyst meet the standards.

[0016] Preferably, a first NOx sensor and a first ammonia sensor are arranged between the ammonia fuel engine and the ammonia storage and release device, a second NOx sensor and a second ammonia sensor are arranged between the mixer and the selective catalytic reducer, and a third NOx sensor and a third ammonia sensor are arranged at the end of the ammonia oxidation catalyst away from the ammonia fuel engine.

[0017] Preferably, the ammonia storage and release device, the first NOx sensor, the first ammonia sensor, the second NOx sensor, the second ammonia sensor, the third NOx sensor, and the third ammonia sensor are connected to a controller.

[0018] Preferably, the types of the ammonia storage and release catalyst include molecular sieve catalysts, noble metal catalysts, and metal oxide catalysts.

[0019] Preferably, the types of the molecular sieve catalysts include 3A molecular sieves, 4A molecular sieves, 5A molecular sieves, 10Z molecular sieves, 13Z molecular sieves, Y-type molecular sieves, Beta molecular sieves, ZSM5 molecular sieves, and SAPO-type molecular sieves.

[0020] Preferably, the ammonia storage and release catalyst is arranged in a single layer or multiple layers in the ammonia storage and release device.

[0021] Preferably, the operating modes of the ammonia fuel engine include compression ignition, diesel pilot ignition, and spark ignition.

[0022] Compared with the prior art, the present application has the following beneficial effects:

[0023] The present application can realize flexible storage and release of unburned ammonia of the ammonia fuel engine through the ammonia storage and release device, cope with the proportion difference of unburned ammonia and NOx emissions of the ammonia fuel engine under different operating conditions, and ensure the optimal proportion of reducing agent ammonia and NOx in front of the selective catalytic reducer at all times, thereby realizing integrated purification of unburned ammonia and NOx in the exhaust gas of the ammonia fuel engine, and simultaneously eliminating the additional reducing agent storage, supply, and injection system. BRIEF DESCRIPTION OF DRAWINGS

[0024] Other features, objects, and advantages of the present application will become more apparent from the following detailed description of non-limiting embodiments, made with reference to the accompanying drawings:

[0025] Figure 1 is a schematic diagram of a processing device;

[0026] shown in the drawings:

[0027] DETAILED DESCRIPTION

[0028] The application will be described in detail below with specific examples. The following examples will help those skilled in the art to further understand the application, but do not limit the application in any form. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the application. These are within the scope of protection of the application.

[0029] Example 1

[0030] As shown in the figure, the embodiment includes: ammonia storage and release device 2, ammonia storage and release catalyst 3, mixer 4, selective catalytic reduction device 5 and ammonia oxidation catalyst 6; the ammonia fuel engine 1 exhaust port is sequentially connected with ammonia storage and release device 2, mixer 4, selective catalytic reduction device 5 and ammonia oxidation catalyst 6, and the ammonia storage and release catalyst 3 is arranged in the ammonia storage and release device 2. Figure 1 The first NOx sensor 701 and the first ammonia sensor 801 are arranged between the ammonia fuel engine 1 and the ammonia storage and release device 2, the second NOx sensor 702 and the second ammonia sensor 802 are arranged between the mixer 4 and the selective catalytic reduction device 5, and the third NOx sensor 703 and the third ammonia sensor 803 are arranged at the end away from the ammonia fuel engine 1 of the ammonia oxidation catalyst 6. The ammonia storage and release device 2, the first NOx sensor 701, the first ammonia sensor 801, the second NOx sensor 702, the second ammonia sensor 802, the third NOx sensor 703 and the third ammonia sensor 803 are connected with the controller 9.

[0031] The types of ammonia storage and release catalyst 3 include molecular sieve catalyst, noble metal catalyst and metal oxide catalyst. The types of molecular sieve catalyst include 3A molecular sieve, 4A molecular sieve, 5A molecular sieve, 10Z molecular sieve, 13Z molecular sieve, Y-type molecular sieve, Beta molecular sieve, ZSM5 molecular sieve and SAPO-type molecular sieve. The working modes of the ammonia fuel engine 1 include compression ignition, diesel pilot ignition and spark ignition.

[0032] Working principle:

[0033]

[0034] ​Firstly, the first NOx sensor 701 and the first ammonia sensor 801 measure the NOx and unburned ammonia content in the exhaust gas of the ammonia fuel engine 1 and feed back to the controller 9. When the unburned ammonia is excessive relative to the NOx in the exhaust gas of the ammonia fuel engine 1, the controller 9 controls the ammonia storage releaser 2 to work in the ammonia storage mode to store the excessive ammonia; at the same time, the controller 9 collects the data of the second NOx sensor 702 and the second ammonia sensor 802 to ensure the appropriate ammonia and NOx ratio before the selective catalytic reducer 5 for the SCR reaction, realizing the integrated purification of the unburned ammonia and the NOx; when the NOx is excessive relative to the unburned ammonia in the exhaust gas of the ammonia fuel engine 1, the controller 9 controls the ammonia storage releaser 2 to work in the ammonia release mode to release the reducing agent ammonia for the SCR reaction in the selective catalytic reducer 5; at the same time, the controller 9 collects the data of the second NOx sensor 702 and the second ammonia sensor 802 to ensure the appropriate ammonia and NOx ratio before the selective catalytic reducer 5 for the SCR reaction, realizing the integrated purification of the unburned ammonia and the NOx. Then, according to the measurement values of the first NOx sensor 701 and the first ammonia sensor 801, combined with the exhaust gas flow of the ammonia fuel engine 1, the ammonia storage amount in the ammonia storage releaser 2 is calculated in real time, and the excessive ammonia is released to the ammonia oxidation catalyst 6 to be converted into environmentally friendly nitrogen gas in the ammonia storage full state; finally, the third NOx sensor 703 and the third ammonia sensor 803 confirm whether the NOx and unburned ammonia emissions after the ammonia oxidation catalyst 6 meet the standards.

[0035] In an embodiment, when the unburned ammonia is excessive relative to the NOx, most of the on-off valves on the ammonia storage releaser 2 are controlled to be in the open state, more catalysts are put in to strengthen the unburned ammonia adsorption, at this time, the increased flow area can also reduce the exhaust gas flow rate to facilitate the unburned ammonia adsorption; when the NOx is excessive relative to the unburned ammonia under a few working conditions, most of the on-off valves are closed to reduce the flow area to reduce the unburned ammonia adsorption, and at the same time, the ammonia release mode is realized by heating the ammonia storage releaser 2 through the controller 9.

[0036] Example 2

[0037] Example 2 is a preferred example of Example 1.

[0038] As shown in Figure 1 , the present embodiment comprises: an ammonia fuel engine 1, an ammonia storage releaser 2, an ammonia storage and release catalyst 3, a mixer 4, a selective catalytic reducer 5, an ammonia oxidation catalyst 6, a NOx sensor, an ammonia sensor, a controller 9; the ammonia storage releaser 2, the mixer 4, the selective catalytic reducer 5, and the ammonia oxidation catalyst 6 are connected in sequence and are arranged behind the ammonia fuel engine 1. The controller 9 realizes flexible control of the ammonia storage and release in the ammonia storage releaser 2 by controlling the flow rate of the exhaust gas in the ammonia storage releaser 2, the temperature of the ammonia storage and release catalyst 3, and the like.

[0039] The first NOx sensor 701 and the first ammonia sensor 801 are arranged to measure the NOx and unburned ammonia in the exhaust gas of the ammonia fuel engine 1, the second NOx sensor 702 and the second ammonia sensor 802 are arranged to measure the NOx and unburned ammonia between the mixer 4 and the selective catalytic reducer 5, and the third NOx sensor 703 and the third ammonia sensor 803 are arranged to measure whether the NOx and unburned ammonia after the ammonia oxidation catalyst 6 meet the emission standards. The first NOx sensor 701, the second NOx sensor 702, the third NOx sensor 703, the first ammonia sensor 801, the second ammonia sensor 802, the third ammonia sensor 803, and the ammonia storage and release device 2 are connected to the controller 9.

[0040] In an embodiment, the ammonia storage and release catalyst 3 inside the ammonia storage and release device 2 is configured to include a molecular sieve catalyst, a noble metal catalyst, and a metal oxide catalyst.

[0041] In an embodiment, the types of the molecular sieve catalyst include a 3A molecular sieve, a 4A molecular sieve, a 5A molecular sieve, a 10Z molecular sieve, a 13Z molecular sieve, a Y-type molecular sieve, a Beta molecular sieve, a ZSM5 molecular sieve, and a SAPO-type molecular sieve.

[0042] In an embodiment, the structure of the ammonia storage and release catalyst 3 includes a single layer and multiple layers.

[0043] In an embodiment, the working modes of the ammonia fuel engine 1 include compression ignition, diesel pilot ignition, and spark ignition.

[0044] The embodiment also provides a working method of the ammonia fuel engine exhaust emission integrated purification aftertreatment device with the ammonia storage and release function, which includes the following steps:

[0045] Step S1, the first NOx sensor 701 and the first ammonia sensor 801 measure the NOx and unburned ammonia in the exhaust gas of the ammonia fuel engine 1 and feed back to the controller 9.

[0046] Step S2, when the unburned ammonia in the exhaust gas of the ammonia fuel engine 1 is excessive relative to the NOx, the controller 9 controls the ammonia storage and release device 2 to work in the ammonia storage mode to store the excessive ammonia.

[0047] Meanwhile, the controller 9 collects the data of the second NOx sensor 702 and the second ammonia sensor 802 to ensure the appropriate ammonia and NOx ratio before the selective catalytic reducer 5 for the SCR reaction, so as to realize the integrated purification of the unburned ammonia and the NOx.

[0048] Step S3, when the NOx in the exhaust gas of the ammonia fuel engine 1 is excessive relative to the unburned ammonia, the controller 9 controls the ammonia storage and release device 2 to work in the ammonia release mode to release the reducing agent ammonia for the SCR reaction in the selective catalytic reducer 5.

[0049] Meanwhile, the controller 9 collects the second NOx sensor 702 and the second ammonia sensor 802 data to ensure the appropriate ammonia and NOx ratio before the selective catalytic reducer 5 for the SCR reaction, to achieve the integrated purification of the unburned ammonia and NOx;

[0050] Step S4, according to the measurement values of the first ammonia sensor 801 and the second ammonia sensor 802, combined with the exhaust flow of the ammonia fuel engine 1, the ammonia storage amount in the ammonia storage and release device 2 is calculated in real time, and when the ammonia storage is full, the excess ammonia is released to the ammonia oxidation catalyst 6 to convert into environmentally friendly nitrogen;

[0051] Step S5, the third NOx sensor 703 and the third ammonia sensor 803 confirm whether the NOx and unburned ammonia emissions after the ammonia oxidation catalyst 6 meet the standards.

[0052] In the description of the present application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0053] The specific embodiments of the present application are described above. It should be understood that the present application is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essential content of the present application. The embodiments of the present application and the features in the embodiments can be arbitrarily combined with each other without conflict.

Claims

1. A method of operating an ammonia fuel engine exhaust emission integrated purification aftertreatment device, characterized by, The ammonia fuel engine emission integrated purification aftertreatment device comprises an ammonia storage releaser (2), an ammonia storage and release catalyst (3), a mixer (4), a selective catalytic reduction device (5) and an ammonia oxidation catalyst (6); The ammonia fuel engine (1) is sequentially connected with the ammonia storage releaser (2), the mixer (4), the selective catalytic reduction device (5) and the ammonia oxidation catalyst (6) in sequence; The ammonia storage and release catalyst (3) is arranged in the ammonia storage releaser (2); The first NOx sensor (701) and the first ammonia sensor (801) are arranged between the ammonia fuel engine (1) and the ammonia storage releaser (2), the second NOx sensor (702) and the second ammonia sensor (802) are arranged between the mixer (4) and the selective catalytic reduction device (5), and the third NOx sensor (703) and the third ammonia sensor (803) are arranged at the end of the ammonia oxidation catalyst (6) away from the ammonia fuel engine (1); The ammonia storage releaser (2), the first NOx sensor (701), the first ammonia sensor (801), the second NOx sensor (702), the second ammonia sensor (802), the third NOx sensor (703) and the third ammonia sensor (803) are connected with the controller (9); The working method of the ammonia fuel engine emission integrated purification aftertreatment device comprises the following steps: In step S1, the first NOx sensor (701) and the first ammonia sensor (801) measure the NOx and unburned ammonia content in the exhaust gas of the ammonia fuel engine (1) and feed back to the controller (9); In step S2, when the unburned ammonia in the exhaust gas of the ammonia fuel engine (1) is excessive relative to the NOx, the controller (9) controls the ammonia storage releaser (2) to work, and the ammonia storage releaser (2) stores the excessive ammonia in the ammonia storage mode; Meanwhile, the controller (9) collects the data of the second NOx sensor (702) and the second ammonia sensor (802) to ensure that the appropriate ammonia and NOx ratio before the selective catalytic reduction device (5) is used for the SCR reaction, so as to realize the integrated purification of unburned ammonia and NOx; In step S3, when the NOx in the exhaust gas of the ammonia fuel engine (1) is excessive relative to the unburned ammonia, the controller (9) controls the ammonia storage releaser (2) to work in the ammonia release mode to release the reducing agent ammonia for the SCR reaction in the selective catalytic reduction device (5); Meanwhile, the controller (9) collects the data of the second NOx sensor (702) and the second ammonia sensor (802) to ensure that the appropriate ammonia and NOx ratio before the selective catalytic reduction device (5) is used for the SCR reaction, so as to realize the integrated purification of unburned ammonia and NOx; Step S4, according to the measurement values of the first NOx sensor (701) and the first ammonia sensor (801), combined with the exhaust flow of the ammonia fuel engine (1), the ammonia storage amount in the ammonia storage and release catalyst (2) is calculated in real time, and the excess ammonia is released to the ammonia oxidation catalyst (6) to convert into environmentally friendly nitrogen in the ammonia storage full state; Step S5, the third NOx sensor (703) and the third ammonia sensor (803) confirm whether the NOx and unburned ammonia emissions after the ammonia oxidation catalyst (6) meet the standards.

2. The method of operating an ammonia fuel engine exhaust integrated purification aftertreatment device of claim 1, wherein: The types of the ammonia storage and release catalyst (3) include molecular sieve catalyst, noble metal catalyst and metal oxide catalyst.

3. The method of operating an ammonia fuel engine exhaust integrated purification aftertreatment device of claim 2, wherein: The types of the molecular sieve catalyst include 3A molecular sieve, 4A molecular sieve, 5A molecular sieve, 10Z molecular sieve, 13Z molecular sieve, Y-type molecular sieve, Beta molecular sieve, ZSM5 molecular sieve, SAPO-type molecular sieve.

4. The method of operating an ammonia fuel engine emission integrated purification aftertreatment device of claim 1, wherein: The ammonia storage and release catalyst (3) is arranged in single or multiple layers in the ammonia storage and release catalyst (2).

5. The method of operating an ammonia fuel engine emission integrated purification aftertreatment device of claim 1, wherein: The working modes of the ammonia fuel engine (1) include compression ignition, diesel pilot ignition and spark ignition.

6. The method of operating an ammonia fuel engine emission integrated purification aftertreatment device of claim 1, wherein: The ammonia storage and release catalyst (2) is provided with an on-off valve, and the number of catalysts and the exhaust flow rate in the ammonia storage and release catalyst (2) are adjusted by the controller (9).

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