Integrated treatment device and method for ship ammonia fuel engine

Abstract

The present invention discloses a ship ammonia fuel engine exhaust gas treatment device and treatment method, which relates to the technical field of ship engine exhaust gas treatment, and solves the problem of N2O generated by ammonia fuel engines and rapid SCR reactions and ammonia escape. The present invention comprises an ammonia fuel tank, an ammonia fuel engine, a turbocharger and a pollutant treatment device connected in sequence; the ammonia fuel tank and the pollutant treatment device are connected; the concentration of NH3 in the exhaust gas is detected by NH3 sensor 1; when the NH3 concentration is too high, the exhaust gas directly enters the pollutant treatment device and undergoes catalytic oxidation of NH3; when the NH3 concentration is low, the exhaust gas enters the pollutant treatment device through branch 2 and the exhaust gas does not undergo catalytic oxidation of NH3; an NH3 sensor 2 is provided at the outlet of the pollutant treatment device. The present invention integrates a variety of catalysts in the same reactor, reduces the volume of the reactor, and improves the space utilization rate of the ship; and uses the residual NH3 in the exhaust gas as a raw material for the SCR reaction, thereby reducing fuel consumption and reducing NH3 emissions.

Description

Technical Field

[0001] The present invention relates to the technical field of ship engine exhaust treatment, and in particular to an integrated treatment device and method for a ship ammonia fuel engine. Background Art

[0002] At present, in the process of searching for zero-carbon / low-carbon ship propulsion, ammonia and ammonia fuel engines, as typical zero-carbon fuels, have received extensive attention. However, the exhaust gas of ammonia fuel engines contains high levels of NO x , N2O and escaped NH3.

[0003] The most widely used denitrification technology for ships is the selective catalytic reduction (SCR) technology. The ship SCR technology mainly adopts the standard SCR technology, using NH3 as a reducing agent to reduce NO in the ship exhaust gas under the action of the catalyst. x (mainly NO) is reduced to N2. At present, the standard SCR technology is relatively mature, but there are problems such as slow SCR reaction rate and high reaction temperature requirements, which seriously affect the application of SCR in ships (especially the post-turbine SCR method). Compared with the standard SCR reaction, the fast SCR reaction increases the proportion of NO2 in nitrogen oxides (about 50%), and NO and NO2 react with NH3 at the same time. The reaction rate of the fast SCR reaction is 10 times that of the standard SCR reaction rate. At the same time, the fast SCR reaction has a lower reaction temperature and higher low-temperature reaction efficiency.

[0004] However, there is a side reaction of generating N2O in the fast SCR reaction, and ammonia fuel engines also produce N2O, so the treatment of N2O gas is also extremely important. At the same time, the unburned ammonia slip of ammonia fuel engines and the ammonia slip in the SCR reaction are also issues worthy of attention. Summary of the invention

[0005] In order to solve the above-mentioned problems of N2O generated by ammonia fuel engines and rapid SCR reactions and ammonia escape, the present invention proposes an integrated treatment device and treatment method for ammonia fuel engines for ships. The present invention integrates multiple catalysts in the same reactor, reduces the volume of the reactor, and improves the space utilization of the ship; and uses the residual NH3 in the exhaust gas as the raw material for the SCR reaction, which reduces fuel consumption and reduces NH3 emissions.

[0006] The present invention proposes an integrated treatment device for a marine ammonia fuel engine, which specifically comprises an ammonia fuel engine system, a nitrogen-containing pollutant treatment system and a controller, wherein the nitrogen-containing pollutant treatment system is connected to the ammonia fuel engine system and the controller respectively; the nitrogen-containing pollutant treatment system comprises a pollutant treatment device, an NH3 sensor 1, an NH3 sensor 2, a control valve 5, a control valve 6, a branch 2, a branch 3 and a heating branch, and the pipeline connecting the ammonia fuel engine system and the pollutant treatment device is sequentially provided with an NH3 sensor 1 and a control valve 5; an NH3 oxidation catalyst and a NO oxidation catalyst are arranged inside the pollutant treatment device; the inlet of the branch 2 is connected to the inlet of the control valve 5, and the outlet is connected to the pollutant treatment device and is arranged between the NH3 oxidation catalyst and the NO oxidation catalyst; the exhaust gas enters the pollutant treatment device through the control valve 5 or the branch 2; the outlet pipeline of the pollutant treatment device is sequentially provided with an NH3 sensor 2 and a control valve 6; the inlet of the branch 3 is connected to the inlet of the control valve 6, and the outlet of the branch 3 is connected to the outlet of the ammonia fuel engine system; the heating branch is respectively connected to the ammonia fuel engine system and the pollutant treatment device, and the ammonia fuel engine system heats the pollutant treatment device through the heating branch.

[0007] Furthermore, the branch line 2 is provided with a control valve 2, and the branch line 3 is provided with a control valve 7; the controller is connected to the control valve 2 and the control valve 7 respectively.

[0008] Furthermore, the pollutant treatment device includes a shell, a treatment device inlet is provided at one end of the shell, and a treatment device outlet is provided at the other end, the treatment device inlet is connected to the control valve five, the treatment device outlet is connected to the control valve six, and an NH3 sensor two is provided on the pipeline between the treatment device outlet and the control valve six; an NH3 oxidation catalyst, a NO oxidation catalyst, an SCR catalyst and an N2O catalytic decomposition catalyst are arranged in sequence inside the shell from the treatment device inlet to the treatment device outlet; a branch two inlet is provided on the shell between the NH3 oxidation catalyst and the NO oxidation catalyst, and the branch two inlet is connected to branch two.

[0009] Furthermore, an air injection valve is arranged on the shell at a position corresponding to between the NH3 oxidation catalyst and the NO oxidation catalyst; an NH3 injection valve is arranged on the shell between the NO oxidation catalyst and the SCR catalyst, and the NH3 injection valve is connected to the ammonia fuel engine system.

[0010] Furthermore, an oxygen sensor is arranged on the shell at a position corresponding to between the NH3 oxidation catalyst and the NO oxidation catalyst; and a NO sensor, a third NH3 sensor and a NO2 sensor are arranged on the shell between the NO oxidation catalyst and the SCR catalyst.

[0011] Furthermore, the pollutant treatment device also includes a heating tube, which includes a heating tube body, a high-temperature exhaust gas outlet and a high-temperature exhaust gas inlet; one end of the heating tube body is connected to the high-temperature exhaust gas outlet, and the other end is connected to the high-temperature exhaust gas inlet; the high-temperature exhaust gas outlet is arranged on the shell between the treatment device inlet and the NH3 oxidation catalyst; the high-temperature exhaust gas inlet is arranged on the shell between the treatment device outlet and the N2O catalytic decomposition catalyst; the heating tube body is arranged inside the shell and passes through the center of the N2O catalytic decomposition catalyst, the SCR catalyst, the NO oxidation catalyst and the NH3 oxidation catalyst in sequence; the high-temperature exhaust gas inlet and the high-temperature exhaust gas outlet are connected to the ammonia fuel engine system through heating branches respectively.

[0012] Furthermore, the heating branch includes branch one and branch four, the outlet of branch one is connected to the high-temperature exhaust gas inlet, and the inlet is connected to the ammonia fuel engine system; the inlet of branch four is connected to the high-temperature exhaust gas outlet, and the outlet is connected to the ammonia fuel engine system.

[0013] Furthermore, a control valve 1 is arranged on the branch 1, and the control valve 1 is connected to the controller; and a control valve 4 is arranged on the branch 4.

[0014] Furthermore, the ammonia fuel engine system includes an ammonia fuel engine, a turbocharger, an ammonia fuel tank and control valve three, and the ammonia fuel tank, the ammonia fuel engine, the turbocharger and the control valve three are connected in sequence; the ammonia fuel tank is also connected to the NH3 injection valve; the inlet of branch one is connected to the outlet of the ammonia fuel engine; the outlet of branch four is connected to the outlet of the turbocharger.

[0015] A treatment method using the above-mentioned integrated treatment device for a marine ammonia fuel engine comprises the following steps:

[0016] Step 1: The tail gas generated by a part of the ammonia fuel engine system heats the pollutant treatment device and then merges with the other part of the tail gas, and the NH3 concentration of the tail gas is detected by NH3 sensor 1; when the NH3 concentration is higher than the system setting value, the tail gas enters the pollutant treatment device through control valve 5 to catalytically oxidize NH3 to generate N2; when the NH3 concentration is lower than the system setting value, control valve 5 is closed, and the tail gas enters the pollutant treatment device through branch 2 without catalytic oxidation of NH3;

[0017] Step 2: A portion of NO in the exhaust gas is oxidized to NO2 by the catalyst, and the controller determines the concentration ratio of NO and NO2 through the sensor. When the concentration of NO is greater than that of NO2, air is added to the pollutant treatment device;

[0018] Step 3: The controller detects the concentrations of NH3, NO and NO2 in the pollutant treatment device through sensors. If the NH3 concentration in the exhaust gas is insufficient to support the denitrification requirement, NH3 is added to the pollutant treatment device through the ammonia fuel engine system for a rapid SCR reaction; N2O in the exhaust gas is decomposed into N2 and O2 under the action of the catalyst;

[0019] Step 4: NH3 sensor 2 detects the treated exhaust gas. If the NH3 concentration is higher than the emission limit, the exhaust gas is transported back to the nitrogen-containing pollutant treatment system via branch 3 for treatment.

[0020] The beneficial effects of the integrated treatment device and treatment method for a marine ammonia fuel engine described in the present invention are:

[0021] (1) The integrated treatment device and treatment method for a marine ammonia fuel engine described in the present invention overcomes the problem of N2O and ammonia slip generated by the ammonia fuel engine and the rapid SCR reaction. By setting a N2O catalytic decomposition catalyst in the pollutant treatment device to catalytically decompose N2O, the emission of N2O gas from the ammonia fuel engine is effectively reduced; the ammonia in the exhaust gas is oxidized by an NH3 oxidation catalyst, and multiple sensors are used for monitoring and control to ensure that the ammonia fuel engine can minimize ammonia slip under different operating conditions. The device has high applicability. At the same time, the residual NH3 in the exhaust gas is used as the raw material for SCR, which reduces fuel consumption;

[0022] (2) The integrated treatment device and treatment method for ammonia fuel engine of a ship described in the present invention is based on the rapid SCR reaction to treat NO x While improving the denitration rate and efficiency, part of the tail gas is used to heat the pollutant treatment device, which reduces the requirements for the SCR reaction temperature and can significantly improve the SCR reaction rate and low-temperature removal efficiency;

[0023] (3) The integrated processing device and method for a ship ammonia fuel engine described in the present invention integrates multiple catalysts into the same reaction, thereby reducing the volume of the reactor and improving the space utilization of the ship. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0025] In the attached picture:

[0026] Figure 1 It is a structural schematic diagram of an integrated processing device for a marine ammonia fuel engine according to the present invention;

[0027] Figure 2 It is a schematic cross-sectional structure diagram of a pollutant treatment device of an integrated treatment device for a marine ammonia fuel engine according to the present invention;

[0028] Among them: 1- ammonia fuel engine, 2- turbocharger, 3- pollutant treatment device, 3-1- high temperature exhaust gas outlet, 3-2- NH3 oxidation catalyst, 3-3- oxygen sensor, 3-4- air injection valve, 3-5- NO oxidation catalyst, 3-6- NO sensor, 3-7- NH3 sensor three, 3-8- NO2 sensor, 3-9- NH3 injection valve, 3-10- SCR catalyst, 3-11- N2O catalytic decomposition catalyst, 3-12- high temperature exhaust gas inlet Mouth, 3-13-inlet of branch two, 3-14-shell, 3-15-heating tube, 3-16-inlet of treatment device, 3-17-outlet of treatment device, 4-controller, 5-NH3 sensor one, 6-ammonia fuel tank, 7-NH3 sensor two, 8-control valve one, 9-control valve two, 10-control valve three, 11-control valve four, 12-control valve five, 13-control valve six, 14-control valve seven, 15-branch one, 16-branch two, 17-branch three, 18-branch four. DETAILED DESCRIPTION

[0029] The specific implementation of the present invention is further described in detail below with reference to the accompanying drawings:

[0030] Specific implementation method 1: See Figure 1-Figure 2Specific description of this embodiment. The integrated treatment device for a ship ammonia fuel engine described in this embodiment specifically includes an ammonia fuel engine system, a nitrogen-containing pollutant treatment system and a controller 4. The nitrogen-containing pollutant treatment system is connected to the ammonia fuel engine system and the controller 4 respectively; the nitrogen-containing pollutant treatment system includes a pollutant treatment device 3, an NH3 sensor 1 5, an NH3 sensor 2 7, a control valve 5 12, a control valve 6 13, a branch 2 16, a branch 3 17 and a heating branch. The pipeline connecting the ammonia fuel engine system and the pollutant treatment device 3 is sequentially provided with an NH3 sensor 1 5 and a control valve 5 12; an NH3 oxidation catalyst 3-2 and a NO oxidation catalyst are arranged inside the pollutant treatment device 3. agent 3-5; the inlet of branch two 16 is connected to the inlet of control valve five 12, and the outlet is connected to the pollutant treatment device 3 and is arranged between NH3 oxidation catalyst 3-2 and NO oxidation catalyst 3-5; the tail gas enters the pollutant treatment device 3 through control valve five 12 or branch two 16; the outlet pipeline of the pollutant treatment device 3 is sequentially provided with NH3 sensor two 7 and control valve six 13; the inlet of branch three 17 is connected to the inlet of control valve six 13, and the outlet of branch three 17 is connected to the outlet of the ammonia fuel engine system; the heating branch is respectively connected to the ammonia fuel engine system and the pollutant treatment device 3, and the ammonia fuel engine system heats the pollutant treatment device 3 through the heating branch. The controller 4 monitors the NH3 concentration in the treated tail gas through the NH3 sensor two 7, and if the NH3 concentration is higher than the emission limit, the tail gas is recirculated back to the pollutant treatment device 3 through the branch three 17 for further treatment.

[0031] The branch 2 16 is provided with a control valve 2 9, and the branch 3 17 is provided with a control valve 7 14; the controller 4 is respectively connected to the control valve 2 9 and the control valve 7 14. The controller 4 controls the switching behaviors of the control valve 2 9, the control valve 5 12, the control valve 6 13 and the control valve 7 14 by receiving the concentration signals of the NH3 concentration sensor 1 5 and the NH3 concentration sensor 2 7.

[0032] The pollutant treatment device 3 includes a shell 3-14, one end of the shell 3-14 is provided with a treatment device inlet 3-16, the other end is provided with a treatment device outlet 3-17, the treatment device inlet 3-16 is connected to the control valve 5 12, the treatment device outlet 3-17 is connected to the control valve 6 13, and the pipeline between the treatment device outlet 3-17 and the control valve 6 13 is provided with an NH3 sensor 27; the inside of the shell 3-14 is provided with NH3 oxygen sensors 27 in sequence from the treatment device inlet 3-16 to the treatment device outlet 3-17. The NH3 oxidation catalyst 3-2, the NO oxidation catalyst 3-5, the SCR catalyst 3-10 and the N2O catalytic decomposition catalyst 3-11 are shaped catalysts, which are tightly connected to the shell 3-14; the shell 3-14 between the NH3 oxidation catalyst 3-2 and the NO oxidation catalyst 3-5 is provided with a branch second inlet 3-13, and the branch second inlet 3-13 is connected to the branch second 16.

[0033] The NH3 oxidation catalyst 3-2 is a ruthenium-based catalyst, which oxidizes NH3 in the tail gas into NO. The NO oxidation catalyst 3-5 is used to oxidize NO in the tail gas into NO2.

[0034] An air injection valve 3-4 is arranged on the shell 3-14 at a position corresponding to between the NH3 oxidation catalyst 3-2 and the NO oxidation catalyst 3-5, and is used to supply air to the pollutant treatment device 3; an NH3 injection valve 3-9 is arranged on the shell 3-14 between the NO oxidation catalyst 3-5 and the SCR catalyst 3-10, and the NH3 injection valve 3-9 is connected to the ammonia fuel engine system, and is used to supply NH3 to the pollutant treatment device 3.

[0035] An oxygen sensor 3-3 is provided on the housing 3-14 at a position corresponding to between the NH3 oxidation catalyst 3-2 and the NO oxidation catalyst 3-5, for measuring the oxygen concentration in the exhaust gas; a NO sensor 3-6, an NH3 sensor 3-7 and a NO2 sensor 3-8 are provided on the housing 3-14 between the NO oxidation catalyst 3-5 and the SCR catalyst 3-10, for measuring the concentrations of NO, residual NH3 and NO2 in the exhaust gas. The controller 4 receives the concentration signals of the oxygen sensor 3-3, the NO sensor 3-6 and the NO2 sensor 3-8 respectively, and judges whether the value of NO:NO2 is around 1. When the NO concentration is too high, it calculates the required additional oxygen, and controls the injection amount of the air injection valve 3-4 and the injection behavior of the NH3 injection valve 3-9. The controller 4 receives the concentration signal of the NH3 sensor 3-7, combines the concentration signals of the NO sensor 3-6 and the NO2 sensor 3-8, calculates the additional amount of NH3 required for a rapid SCR reaction to occur on the SCR catalyst 3-10, and controls the injection behavior of the NH3 injection valve 3-9. The NH3 required for the rapid SCR reaction is provided by the ammonia fuel tank 6 through the NH3 injection valve 3-9.

[0036] The pollutant treatment device 3 also includes a heating pipe 3-15, which includes a heating pipe body, a high-temperature exhaust gas outlet 3-1 and a high-temperature exhaust gas inlet 3-12; one end of the heating pipe body is connected to the high-temperature exhaust gas outlet 3-1, and the other end is connected to the high-temperature exhaust gas inlet 3-12; the high-temperature exhaust gas outlet 3-1 is arranged on the shell 3-14 between the treatment device inlet 3-16 and the NH3 oxidation catalyst 3-2; the high-temperature exhaust gas inlet 3-12 is arranged on the shell 3-14 between the treatment device outlet 3-17 and the N2O catalytic decomposition catalyst 3-11; the heating pipe body is arranged inside the shell 3-14 and passes through the center of the N2O catalytic decomposition catalyst 3-11, the SCR catalyst 3-10, the NO oxidation catalyst 3-5 and the NH3 oxidation catalyst 3-2 in sequence; the high-temperature exhaust gas inlet 3-12 and the high-temperature exhaust gas outlet 3-1 are respectively connected to the ammonia fuel engine system through heating branches.

[0037] The heating branch includes branch 15 and branch 4 18. The outlet of branch 15 is connected to the high-temperature tail gas inlet 3-12, and the inlet is connected to the ammonia fuel engine system; the inlet of branch 4 18 is connected to the high-temperature tail gas outlet 3-1, and the outlet is connected to the ammonia fuel engine system. A part of the tail gas generated by the ammonia fuel engine system is passed into the heating pipe 3-15 of the pollutant treatment device 3 through branch 15, and the inside of the pollutant treatment device 3 is heated by the tail gas to provide temperature conditions for each catalytic reaction. Then the tail gas leaves from the high-temperature tail gas outlet 3-1, passes through the one-way valve 4 11, and mixes with the tail gas discharged from the turbocharger 2. A control valve 8 is set on branch 15.

[0038] The branch 15 is provided with a control valve 18, and the control valve 18 is connected to the controller 4; the branch 4 18 is provided with a control valve 4 11.

[0039] The ammonia fuel engine system includes an ammonia fuel engine 1, a turbocharger 2, an ammonia fuel tank 6 and a control valve three 10, and the ammonia fuel tank 6, the ammonia fuel engine 1, the turbocharger 2 and the control valve three 10 are connected in sequence; the ammonia fuel tank 6 is also connected to the NH3 injection valve 3-9; the inlet of branch one 15 is connected to the outlet of the ammonia fuel engine 1; the outlet of branch four 18 is connected to the outlet of the turbocharger 2.

[0040] A treatment method using the above-mentioned integrated treatment device for a marine ammonia fuel engine comprises the following steps:

[0041] Step 1, a part of the exhaust gas of the ammonia fuel engine 1 enters the turbocharger 2 for supercharging, and the other part of the exhaust gas enters the heating pipe 3-15 of the pollutant treatment device 3 through the branch 15 to heat the pollutant treatment device 3, and then passes through the control valve 4 11 through the pipeline to merge with the exhaust gas supercharged by the turbocharger 2; the NH3 concentration of the merged exhaust gas is detected by the NH3 sensor 15; when the NH3 concentration is higher than the system setting value, the exhaust gas enters the pollutant treatment device 3 through the control valve 5 12 to catalytically oxidize NH3 to generate N2; when the NH3 concentration is lower than the system setting value, the control valve 5 12 is closed, and the exhaust gas enters the pollutant treatment device 3 through the branch 2 16 without catalytically oxidizing NH3;

[0042] Step 2: After passing through the NO oxidation catalyst, under the action of O2, part of the NO in the exhaust gas is oxidized to NO2 by the catalyst. The controller 4 calculates whether the NO:NO2 ratio reaches 1:1 through the concentration data transmitted by the NO sensor 3-6, the NO2 sensor and the oxygen sensor 3-3. When the NO concentration is too high, the controller calculates the amount of oxygen required to be increased according to the concentrations of NO, NO2 and O2, and controls the air injection valve to inject an appropriate amount of air to further oxidize NO, thereby achieving the required NO:NO2 value.

[0043] Step 3, the controller 4 detects the concentrations of NH3, NO and NO2 in the pollutant treatment device 3 through the sensor. If the concentration of NH3 in the tail gas is not enough to support the denitration requirement, the controller 4 controls the NH3 injection valve 3-9 to inject an appropriate amount of NH3 into the pollutant treatment device 3 through the ammonia fuel tank 6. NH3, NO and NO2 undergo a rapid SCR reaction under the action of the SCR catalyst 3-10. The tail gas finally enters the N2O catalytic decomposition catalyst, and N2O is decomposed into N2 and O2 under the action of the catalyst.

[0044] Step 4: The treated exhaust gas comes out of the pollutant treatment device 3, and the NH3 sensor 2 7 detects the treated exhaust gas and transmits the data to the controller 4. If the NH3 concentration is higher than the emission limit, the controller 4 closes the control valve 6 13 and opens the control valve 7 14, and transports the exhaust gas back to the outlet of the control valve 3 10 via the branch 3 17 instead of being directly discharged into the atmosphere; when the NH3 concentration at the NH3 concentration sensor 7 is lower than the emission limit, the controller 4 opens the control valve 6 13 and closes the control valve 7 14 at the same time, so that the exhaust gas is directly discharged into the atmosphere.

[0045] The specific working process of the integrated treatment device for a marine ammonia fuel engine described in the present invention is as follows:

[0046] like Figure 1 As shown, after the ship exhaust gas comes out of the ammonia fuel engine 1, a part of the exhaust gas enters the turbocharger 2 for supercharging, and the other part of the ship exhaust gas is separated from the front end of the turbocharger 2 and enters the pollutant treatment device 3 to provide the required energy for the operation of the device, and finally mixed with the exhaust gas at the rear end of the turbocharger 2 to enter the pollutant treatment device 3; the NH3 concentration sensor 15 after the turbocharger 2 monitors the NH3 concentration in the exhaust gas and transmits the data to the controller 4. When the NH3 concentration at this place does not reach the system set value due to the working condition of the ammonia fuel engine 1, the controller 4 closes the control valve 5 12 and opens the control valve 2 9 at the same time, so that the exhaust gas enters the pollutant treatment device 3 through the branch 2 16 without passing through the NH3 oxidation catalyst 3-2;

[0047] When the NH3 concentration at the NH3 concentration sensor 5 exceeds the system set value due to the operating condition of the ammonia fuel engine 1, the controller 4 opens the control valve 5 12 and closes the control valve 2 9 at the same time, so that the exhaust gas enters the pollutant treatment device 3 and passes through the NH3 oxidation catalyst 3-2 to perform catalytic oxidation of NH3.

[0048] Specifically, when the exhaust gas passes through the NH3 oxidation catalyst 3-2, NH3 and O2 in the ship exhaust gas generate NO under the action of the NH3 oxidation catalyst 3-2, and the reaction equation is as follows:

[0049]

[0050] The ship's exhaust gas continues to pass through the NO oxidation catalyst 3-5. Under the action of O2, part of the NO in the exhaust gas is oxidized to NO2. The overall reaction equation is as follows:

[0051]

[0052] The ship's exhaust gas continues to pass through the NO sensor 3-6 and the NO2 sensor 3-8. The controller 4 processes the concentration data transmitted by the NO, NO2 and O2 sensors, and calculates whether the NO:NO2 ratio reaches 1:1. When the NO concentration is too high, the controller 4 calculates the required amount of additional oxygen based on the concentrations of NO, NO2 and O2, and controls the air injection valve 3-4 to inject an appropriate amount of air to further oxidize NO, thereby achieving the required NO:NO2 value.

[0053] The ship's exhaust gas continues to pass through the SCR catalyst 3-10, and a rapid SCR reaction occurs under the action of the catalyst and the reducing agent ammonia. The reaction equation is as follows:

[0054]

[0055] The ship exhaust gas enters N2O. In the device, N2O generated by the ammonia fuel engine 1 and the pollutant treatment device 3 is decomposed into N2 and O2 under the action of the catalyst. The reaction equation is as follows:

[0056]

[0057] After the treated exhaust gas comes out of the nitrogen-containing pollutant treatment device 3, the NH3 concentration sensor 15 detects the NH3 concentration therein and transmits the data to the controller 4. If the concentration is higher than the emission limit, the controller 4 closes the control valve 6 13 and opens the control valve 7 14 at the same time, so that the exhaust gas passes through the branch 3 17 instead of being directly discharged into the atmosphere. When the NH3 concentration at the NH3 concentration sensor 2 7 is lower than the emission limit, the controller 4 opens the control valve 6 13 and closes the control valve 7 14 at the same time, so that the exhaust gas is directly discharged into the atmosphere.

[0058] Summarizing the above implementation cases, the exhaust gas treatment device and treatment method of a ship ammonia fuel engine described in the present invention overcome the problem of N2O and ammonia slip produced by the ammonia fuel engine and the rapid SCR reaction. By setting the N2O catalytic decomposition catalyst 3-11 in the pollutant treatment device 3, the N2O is catalytically decomposed, and the emission of N2O gas in the exhaust gas of the ammonia fuel engine 1 is effectively reduced; the ammonia in the exhaust gas is oxidized by the NH3 oxidation catalyst 3-2, and multiple sensors are used for monitoring and control to ensure that the ammonia fuel engine 1 can minimize ammonia slip under different working conditions, and has high applicability. At the same time, the residual NH3 in the exhaust gas is used as the raw material of SCR to reduce fuel consumption; the exhaust gas treatment device and treatment method of a ship ammonia fuel engine described in the present invention are based on the rapid SCR reaction to treat NO of ammonia fuel ships. xThe process can improve the denitration rate and denitration efficiency, and at the same time, heat the pollutant treatment device through part of the exhaust gas, thereby reducing the requirement for the SCR reaction temperature, and can significantly improve the SCR reaction rate and low-temperature removal efficiency. The exhaust gas treatment device and treatment method of a ship ammonia fuel engine described in the present invention integrate multiple catalysts in the same reactor, thereby reducing the volume of the reactor and improving the space utilization of the ship.

[0059] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the invention. It can also be a reasonable combination of the features recorded in the above implementation methods. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An integrated treatment device for a marine ammonia fuel engine, characterized in that: The invention comprises an ammonia fuel engine system, a nitrogen-containing pollutant treatment system and a controller (4), wherein the nitrogen-containing pollutant treatment system is connected to the ammonia fuel engine system and the controller (4) respectively; the nitrogen-containing pollutant treatment system comprises a pollutant treatment device (3), an NH3 sensor 1 (5), an NH3 sensor 2 (7), a control valve 5 (12), a control valve 6 (13), a branch 2 (16), a branch 3 (17) and a heating branch; the pipeline connecting the ammonia fuel engine system and the pollutant treatment device (3) is provided with the NH3 sensor 1 (5) and the control valve 5 (12) in sequence; the pollutant treatment device (3) is provided with an NH3 oxidation catalyst (3-2) and a NO oxidation catalyst (3-5); the inlet of the branch 2 (16) The exhaust gas enters the pollutant treatment device (3) through the control valve five (12) or the branch two (16); the outlet pipe of the pollutant treatment device (3) is sequentially provided with the NH3 sensor two (7) and the control valve six (13); the inlet of the branch three (17) is connected to the inlet of the control valve six (13), and the outlet of the branch three (17) is connected to the outlet of the ammonia fuel engine system; the heating branch is respectively connected to the ammonia fuel engine system and the pollutant treatment device (3), and the ammonia fuel engine system heats the pollutant treatment device (3) through the heating branch; The pollutant treatment device (3) comprises a shell (3-14), one end of the shell (3-14) is provided with a treatment device inlet (3-16), and the other end is provided with a treatment device outlet (3-17), the treatment device inlet (3-16) is connected to a control valve five (12), the treatment device outlet (3-17) is connected to a control valve six (13), and an NH3 sensor two (7) is provided on the pipeline between the treatment device outlet (3-17) and the control valve six (13); an NH3 oxidation catalyst (3-2), a NO oxidation catalyst (3-5), an SCR catalyst (3-10) and a N2O catalytic decomposition catalyst (3-11) are arranged in sequence inside the shell (3-14) from the treatment device inlet (3-16) to the treatment device outlet (3-17); a branch two inlet (3-13) is provided on the shell (3-14) between the NH3 oxidation catalyst (3-2) and the NO oxidation catalyst (3-5), and the branch two inlet (3-13) is connected to the branch two (16); The pollutant treatment device (3) further comprises a heating tube (3-15), the heating tube (3-15) comprising a heating tube body, a high-temperature tail gas outlet (3-1) and a high-temperature tail gas inlet (3-12); one end of the heating tube body is connected to the high-temperature tail gas outlet (3-1), and the other end is connected to the high-temperature tail gas inlet (3-12); the high-temperature tail gas outlet (3-1) is arranged on the housing (3-14) between the treatment device inlet (3-16) and the NH3 oxidation catalyst (3-2); the high-temperature tail gas inlet (3-12) is connected to the high-temperature tail gas outlet (3-16) and the NH3 oxidation catalyst (3-2); ) is arranged on the shell (3-14) between the treatment device outlet (3-17) and the N2O catalytic decomposition catalyst (3-11); the heating pipe body is arranged inside the shell (3-14) and passes through the center of the N2O catalytic decomposition catalyst (3-11), the SCR catalyst (3-10), the NO oxidation catalyst (3-5) and the NH3 oxidation catalyst (3-2) in sequence; the high-temperature exhaust gas inlet (3-12) and the high-temperature exhaust gas outlet (3-1) are respectively connected to the ammonia fuel engine system through the heating branch; The heating branch comprises a branch one (15) and a branch four (18); the outlet of the branch one (15) is connected to the high-temperature exhaust gas inlet (3-12), and the inlet is connected to the ammonia fuel engine system; the inlet of the branch four (18) is connected to the high-temperature exhaust gas outlet (3-1), and the outlet is connected to the ammonia fuel engine system; The ammonia fuel engine system comprises an ammonia fuel engine (1), a turbocharger (2), an ammonia fuel tank (6) and a control valve three (10), wherein the ammonia fuel tank (6), the ammonia fuel engine (1), the turbocharger (2) and the control valve three (10) are connected in sequence; the ammonia fuel tank (6) is also connected to the NH3 injection valve (3-9); the inlet of branch one (15) is connected to the outlet of the ammonia fuel engine (1); and the outlet of branch four (18) is connected to the outlet of the turbocharger (2).

2. The integrated treatment device for ammonia fuel engines for ships according to claim 1, characterized in that: The branch line 2 (16) is provided with a control valve 2 (9), and the branch line 3 (17) is provided with a control valve 7 (14); the controller (4) is connected to the control valve 2 (9) and the control valve 7 (14) respectively.

3. The integrated treatment device for ammonia fuel engines for ships according to claim 1, characterized in that: An air injection valve (3-4) is arranged on the housing (3-14) at a position corresponding to between the NH3 oxidation catalyst (3-2) and the NO oxidation catalyst (3-5); an NH3 injection valve (3-9) is arranged on the housing (3-14) between the NO oxidation catalyst (3-5) and the SCR catalyst (3-10); the NH3 injection valve (3-9) is connected to an ammonia fuel engine system.

4. The integrated treatment device for ammonia fuel engines for ships according to claim 1, characterized in that: An oxygen sensor (3-3) is arranged on the housing (3-14) at a position corresponding to between the NH3 oxidation catalyst (3-2) and the NO oxidation catalyst (3-5); and a NO sensor (3-6), a third NH3 sensor (3-7) and a NO2 sensor (3-8) are arranged on the housing (3-14) between the NO oxidation catalyst (3-5) and the SCR catalyst (3-10).

5. The integrated treatment device for ammonia fuel engines for ships according to claim 1, characterized in that: The branch line one (15) is provided with a control valve one (8), and the control valve one (8) is connected to the controller (4); the branch line four (18) is provided with a control valve four (11).

6. A treatment method using the integrated treatment device for a marine ammonia fuel engine according to any one of claims 1 to 5, characterized in that: The following steps are involved: Step 1: A portion of the exhaust gas generated by the ammonia fuel engine system heats the pollutant treatment device (3) and then merges with another portion of the exhaust gas, and the NH3 concentration of the exhaust gas is detected by the NH3 sensor 1 (5); when the NH3 concentration is higher than the system set value, the exhaust gas enters the pollutant treatment device (3) through the control valve 5 (12) to catalytically oxidize NH3 to generate N2; when the NH3 concentration is lower than the system set value, the control valve 5 (12) is closed, and the exhaust gas enters the pollutant treatment device (3) through the branch 2 (16) without catalytically oxidizing NH3; Step 2: a portion of NO in the exhaust gas is oxidized to NO2 by the action of a catalyst, and a controller (4) determines the concentration ratio of NO and NO2 through a sensor, and when the concentration of NO is greater than that of NO2, air is added to the pollutant treatment device (3); Step 3: The controller (4) detects the concentrations of NH3, NO and NO2 in the pollutant treatment device (3) through sensors. If the concentration of NH3 in the exhaust gas is insufficient to support the denitrification requirement, NH3 is added to the pollutant treatment device (3) through the ammonia fuel engine system to perform a rapid SCR reaction; N2O in the exhaust gas is decomposed into N2 and O2 under the action of the catalyst; Step 4: NH3 sensor 2 (7) detects the treated exhaust gas. If the NH3 concentration is higher than the emission limit, the exhaust gas is transported back to the nitrogen-containing pollutant treatment system via branch 3 (17) for treatment.

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