Ammonia fuel engine NOx emission catalytic reduction system and method
By linking the intake control unit and intermittent feed unit of the NOx emission catalytic reduction system for ammonia fuel engines, the problems of high load on catalytic equipment and improper reductant supply are solved, achieving efficient NOx exhaust gas treatment and optimized reductant supply, thereby improving the NOx catalytic reduction effect and system flexibility of ammonia fuel engines.
Patent Information
- Application Number
- CN202511181315.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-22
- Publication Date
- 2025-10-28
AI Technical Summary
The existing catalytic reduction method for NOx exhaust gas in ammonia fuel engines results in a large processing load on the catalytic equipment, poor catalytic reduction effect, and difficulty in flexibly controlling the supply of reducing agent according to the amount of NOx exhaust gas, leading to insufficient or excessive supply of reducing agent and causing ammonia escape pollution.
A NOx emission catalytic reduction system for an ammonia-fueled engine is adopted. Through the linkage of the intake control unit and the intermittent feeding unit, the synchronous intermittent supply of NOx exhaust gas and ammonia fuel is realized. The intake control unit is driven by the exhaust gas pressure to ensure that the ammonia fuel supply and NOx exhaust gas volume are kept in the optimal ratio, thereby reducing the load on the catalytic system and avoiding the waste of reducing agent.
It improves the catalytic reduction efficiency of NOx, reduces the load on the catalytic system, avoids pollution problems caused by insufficient or excessive supply of reducing agent, and enhances the flexibility and efficiency of the system.
Smart Images
Figure CN120845157A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of NOx emission treatment for ammonia-fueled engines, and specifically to a catalytic reduction system and method for NOx emissions from ammonia-fueled engines. Background Technology
[0002] Currently, ammonia-fueled engines are widely used in marine power systems. However, these engines emit large amounts of NOx during operation, necessitating the use of catalytic reduction systems to treat this NOx. Current methods for catalytic reduction of NOx primarily involve passing NOx and a reducing agent (such as liquid ammonia fuel) into a catalytic converter where a redox reaction occurs, converting the NOx into harmless nitrogen and water. However, this method often involves continuously feeding NOx and the reducing agent into the catalytic converter, which not only easily leads to a heavy load on the converter and poor catalytic reduction of NOx, but also makes it difficult to control the reducing agent supply based on the amount of NOx fed in. This results in either insufficient reducing agent supply leading to incomplete NOx conversion or excessive reducing agent causing ammonia escape pollution. Therefore, we propose a catalytic reduction system and method for NOx emissions from ammonia-fueled engines. Summary of the Invention
[0003] The purpose of this invention is to provide a catalytic reduction system and method for NOx emissions from ammonia fuel engines. This invention solves the technical problems of existing catalytic reduction methods, which not only easily lead to a large processing load on the catalytic equipment and poor catalytic reduction effect on NOx exhaust gas, but also make it inconvenient to control the amount of reducing agent supplied according to the amount of NOx exhaust gas introduced. This results in either insufficient supply of reducing agent causing incomplete NOx conversion or excessive reducing agent causing ammonia escape pollution.
[0004] The present invention achieves the above objectives through the following technical solutions: A catalytic reduction system for NOx emissions from an ammonia fuel engine is provided for treating NOx exhaust gas emitted from the main body of the ammonia fuel engine. The main body of the ammonia fuel engine is connected to an ammonia fuel inlet pipe and a NOx outlet pipe. The reduction system includes: a side feed pipe connected at one end to the ammonia fuel inlet pipe, and a reduction mechanism connecting the side feed pipe and the NOx outlet pipe. The reduction mechanism includes a housing, a drain port and an exhaust port on the housing, an SCR catalytic system inside the housing, a first processor and a second processor on the housing. One end of the first processor is connected to a NOx discharge pipe, and the other end extends into the housing through a second connecting pipe and is connected to an annular pipe, with the annular pipe located above the SCR catalytic system. One end of the second processor is connected to a side feed pipe, and the other end is connected to an atomizing nozzle inserted at the top of the housing through a first connecting pipe. The first processor is equipped with an intake control unit, which is driven by the NOx waste gas entering the first processor to move to a preset position and then opens to allow the NOx waste gas to be discharged from the first processor. When the NOx waste gas is discharged, it resets and moves back to the initial position. The second processor is equipped with an intermittent feed unit, which is drivenly connected to the intake control unit and is used to allow the ammonia fuel entering the second processor to intermittently enter the first connecting pipe when the intake control unit resets and moves.
[0005] A further improvement is that the intake control unit includes a piston movably disposed within the first processor. The piston has a through hole and a sealing plate for closing the through hole. The diameter of the sealing plate is larger than the diameter of the through hole but smaller than the diameter of the piston. A magnetic plate is connected to one side of the sealing plate through an elastic connector that passes through the piston. An electromagnetic ring is provided on one side of the piston to attract the magnetic plate and move the sealing plate to open the through hole when energized. Contact sensors are provided on both sides of the piston. Protrusions for contacting the two contact sensors are provided at both ends of the inner cavity of the first processor. The piston is also connected to the inner wall of one side of the first processor through an elastic member. When one contact sensor facing the NOx discharge pipe contacts the corresponding bump, the electromagnetic ring is de-energized; when another contact sensor contacts the other bump, the electromagnetic ring is energized.
[0006] A further improvement is that the intake control unit includes a sealing plate inserted into the second processor to seal the inner cavity of the second processor, a rack connected to one side of the sealing plate via an elastic telescopic member, an elastic reset member connecting the rack and the second processor, and a toothed gear set meshing with the rack. The toothed gear set is rotatably mounted on the second processor and is connected to the intake control unit via a transmission member.
[0007] A further improvement is that the transmission component includes a magnetic block slidably disposed within the first processor, and a pull rope with one end connected to the magnetic block and the other end wound around the outer wall of the take-up roller. The take-up roller is elastically rotatably disposed on the first processor, and the take-up roller and the toothed gear set are connected by a sprocket transmission set. When another contact sensor comes into contact with another bump, the electromagnetic ring is also energized to attract the magnetic block.
[0008] A further improvement is that the first processor has a guide rod parallel to the piston axis, which moves through the piston and the magnetic block.
[0009] A further improvement is that the toothed gear set includes a support base on the second processor, a shaft part rotatably disposed in the support base and connected to the sprocket drive group, and several sets of toothed gear bodies slidably disposed on the shaft part. The several sets of toothed gear bodies are connected in sequence, and a toggle block is rotatably connected to one side of one toothed gear body. The toggle block is connected to the output end of the telescopic device and is driven by the telescopic device to switch the engagement of several sets of toothed gear bodies with the rack. The arc length of the missing tooth segment of several sets of missing tooth gear bodies increases sequentially, and the axial length of the missing tooth gear body is matched with the width of the rack.
[0010] A further improvement is that the NOx discharge pipe is equipped with a first pump body and a detection sensor for detecting NOx concentration, and the side feed pipe is equipped with a valve body and a second pump body. The first pump body, the detection sensor, the valve body, the second pump body, the contact sensor, and the electromagnetic ring are all electrically connected to the controller. The controller is configured to de-energize the electromagnetic ring, open the first pump body, and close the second pump body when a contact sensor facing the NOx discharge pipe contacts the corresponding bump; and to energize the electromagnetic ring, close the first pump body, and open the valve body and the second pump body when another contact sensor contacts another bump.
[0011] A further improvement is that a heat-insulating sleeve is fitted on the outer wall of the atomizing nozzle and located inside the housing. The inner wall of the heat-insulating sleeve is provided with a heat-conducting ring for contacting the outer wall of the atomizing nozzle. An annular cavity is formed inside the heat-insulating sleeve, and a first friction ring is fixedly installed inside the annular cavity. The first friction ring and the heat-conducting ring are connected by several sets of heat-conducting plates. A second friction ring is movably fitted on the outer wall of the first friction ring. The outer wall of the second friction ring is provided with several sets of blades. The outer wall of the heat-insulating sleeve is connected to the other end of the first processor and the annular pipe through an air inlet pipe and an air outlet pipe, respectively. Control valves are provided in the air inlet pipe, the air outlet pipe, and the second connecting pipe.
[0012] A further improvement is that both the first processor and the second processor are housed within a protective casing.
[0013] A catalytic reduction method for NOx emissions from an ammonia-fueled engine, utilizing the aforementioned reduction system, includes the following steps: S1: The NOx exhaust gas emitted by the main body of the ammonia fuel engine enters the first processor through the NOx exhaust pipe, driving the intake control unit to move. After the NOx exhaust gas drives the unit to a preset position, the intake control unit opens, allowing the NOx exhaust gas to be discharged from the annular pipe into the housing through the second connecting pipe. S2: When the intake control unit opens to discharge NOx exhaust gas, the intake control unit resets and moves to make the intermittent feeding unit work. The ammonia fuel in the ammonia fuel feed pipe enters the second processor through the side feed pipe and then intermittently and controlledly enters the first connecting pipe and is sprayed out from the atomizing nozzle. S3: After step S2, ammonia fuel and NOx exhaust gas are mixed in the shell and treated by the SCR catalytic system to be reduced into harmless nitrogen and water. Then, nitrogen and water are discharged from the liquid outlet and exhaust outlet, respectively.
[0014] The beneficial effects of this invention are as follows: This invention achieves synchronous intermittent supply of NOx waste gas and ammonia fuel through the coordinated operation of the intake control unit of the first processor and the intermittent feeding unit of the second processor. The intake control unit is driven by the waste gas pressure and controls the intermittent feeding unit in conjunction with it, ensuring that the ammonia fuel supply is always in the optimal ratio with the amount of NOx waste gas entering the shell. This method effectively reduces the continuous working load of the SCR catalytic system in the shell through intermittent treatment, thereby improving the NOx catalytic reduction efficiency. On the other hand, it avoids the problem of incomplete NOx conversion due to insufficient ammonia fuel supply, or the problem of excessive ammonia escape pollution caused by excessive supply, thus effectively reducing ammonia fuel waste. At the same time, the intermittent feeding unit can flexibly adjust the ammonia fuel supply according to the concentration of NOx waste gas introduced, improving the flexibility of the system. Attached Figure Description
[0015] Figure 1 This is a schematic diagram of the reduction system structure of the present invention; Figure 2 This is a schematic diagram of the reduction mechanism of the present invention; Figure 3 For the present invention Figure 2 Structural sectional view; Figure 4 For the present invention Figure 3 A schematic diagram of a local structure in the image; Figure 5 This is a cross-sectional view of the first processor structure of the present invention; Figure 6 For the present invention Figure 5 Enlarged schematic diagram of structure A in the image; Figure 7 This is a schematic diagram of the second processor structure of the present invention; Figure 8 This is a schematic diagram of the toothed gear set structure of the present invention; Figure 9 For the present invention Figure 3 An enlarged schematic diagram of the B structure in the image.
[0016] In the diagram: 100, Ammonia fuel engine body; 200, Ammonia fuel inlet pipe; 300, NOx exhaust pipe; 301, First pump body; 302, Detection sensor; 400, Inlet pipe; 401, Valve body; 402, Second pump body; 500, Reduction mechanism; 501, Housing; 502, Drain port; 503, Exhaust port; 504, SCR catalytic system; 505, Atomizing nozzle; 506, Insulation sleeve; 507, Annular pipe; 508, Protective shell; 509, First processor; 510 511. Second processor; 512. First connecting pipe; 513. Piston; 514. Sealing plate; 515. Magnetic plate; 516. Contact sensor; 517. Protrusion; 518. Electromagnetic ring; 519. Guide rod; 520. Magnetic block; 521. Pull rope; 522. Sealing plate; 523. Rack; 524. Gear set with missing teeth; 525. Telescopic device; 526. Actuating block; 527. Blade; 528. Heat-conducting ring; 529. First friction ring; 530. Second friction ring; 541. Heat-conducting sheet. Detailed Implementation
[0017] The present application will now be described in further detail with reference to the accompanying drawings. It should be noted that the following specific embodiments are only used to further illustrate the present application and should not be construed as limiting the scope of protection of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application based on the above application content.
[0018] Example 1 Please see the appendix Figure 1-7 A catalytic reduction system for NOx emissions from an ammonia fuel engine is used to treat NOx exhaust gas emitted from the main body 100 of the ammonia fuel engine. The ammonia fuel engine body 100 is connected to an ammonia fuel inlet pipe 200 and a NOx discharge pipe 300. Both the ammonia fuel inlet pipe 200 and the NOx discharge pipe 300 are conventional structures in the ammonia fuel engine body 100. The ammonia fuel inlet pipe 200 is used to supply liquid ammonia fuel to the ammonia fuel engine body 100, and the NOx discharge pipe 300 is used to discharge the NOx exhaust gas generated by the ammonia fuel engine body 100. The reduction system includes: a side feed pipe 400 connected at one end to the ammonia fuel feed pipe 200, and a reduction mechanism 500 connecting the side feed pipe 400 and the NOx discharge pipe 300; through the side feed pipe 400, a portion of the ammonia fuel can enter the reduction mechanism 500 and react with the NOx exhaust gas discharged into the reduction mechanism 500 from the NOx discharge pipe 300, using the engine's own ammonia fuel as a reducing agent, without the need to add other solutions (such as urea solution), thus simplifying the system structure; The reduction mechanism 500 includes a housing 501 (preferably a corrosion-resistant alloy housing), a drain port 502 and an exhaust port 503 on the housing 501 (both the drain port 502 and the exhaust port 503 are equipped with solenoid valves, which can be used to conveniently discharge nitrogen and water formed after NOx waste gas reduction by controlling the opening and closing of the solenoid valves at timed intervals), an SCR catalytic system 504 inside the housing 501 (optionally, the SCR catalytic system 504 is a catalytic reaction zone composed of honeycomb catalysts, used to provide the catalyst required for the reaction, and under the action of the catalyst, nitric oxide and nitrogen dioxide are combined with ammonia and oxygen to reduce nitrogen and water, which is widely used in the field and will not be described in detail here), and a first processor 509 on the housing 501. The first processor 509 is connected to the NOx discharge pipe 300 at one end and extends into the housing 501 through the second connecting pipe, where it is connected to the annular pipe 507. The annular pipe 507 is located above the SCR catalytic system 504. In this embodiment, the inner wall of the annular pipe 507 has a nozzle or spray hole for discharging NOx waste gas. The second processor 510 is connected to the side feed pipe 400 at one end and to the atomizing nozzle 505 inserted at the top of the housing 501 through the first connecting pipe 511. During operation, the NOx waste gas is evenly distributed through the annular pipe 507 and then passes downward through the SCR catalytic system 504. At the same time, the atomizing nozzle 505 injects ammonia fuel by spray, which undergoes a reduction reaction on the catalyst surface to generate harmless nitrogen and water. The first processor 509 is equipped with an intake control unit. The intake control unit is driven by the NOx waste gas entering the first processor 509 to move to a preset position and then opens to allow the NOx waste gas to be discharged from the first processor 509. When the NOx waste gas is discharged, it resets and moves to the initial position. The second processor 510 is equipped with an intermittent feeding unit. The intermittent feeding unit is connected to the intake control unit and is used to allow the ammonia fuel entering the second processor 510 to intermittently enter the first connecting pipe 511 when the intake control unit resets and moves. This reduction system realizes the synchronous intermittent supply of NOx waste gas and ammonia fuel through the linkage of the intake control unit and the intermittent feeding unit. The intake control unit is driven by the waste gas pressure and controls the intermittent feeding unit in linkage to ensure that the ammonia fuel supply is always in the optimal ratio with the amount of NOx waste gas entering the shell.
[0019] Please see the appendix Figure 2-7 Preferably, the intake control unit of this embodiment includes a piston 512 movably disposed in the first processor 509. The outer diameter of the piston 512 is adapted to the inner diameter of the first processor 509, and a sealing ring is embedded in its outer circumferential wall. When NOx exhaust gas enters the first processor 509, the pressure inside the first processor 509 increases, and the piston 512 moves. The piston 512 has a through hole in its center, and a sealing plate 513 for sealing the through hole is provided on the piston 512. The diameter of the sealing plate 513 is larger than the diameter of the through hole and smaller than the diameter of the piston 512. Optionally, in this embodiment, the through hole is a stepped hole, with one end facing the NOx discharge pipe 300 being a large-diameter section and the other end being a small-diameter section. The piston 512 abuts against the stepped end face of the stepped hole (the stepped end face refers to the end face formed at the position where the large-diameter section and the small-diameter section are connected inside the stepped hole). The piston 512 closes the small-diameter section of the stepped hole. The diameter of the sealing plate 513 is smaller than the diameter of the large-diameter section of the stepped hole but larger than the diameter of the small-diameter section of the stepped hole. When the sealing plate 513 moves away from the stepped end face, NOx exhaust gas is discharged. A magnetic plate 514 is connected to one side of the sealing plate 513 via an elastic connector that passes through the piston 512. Optionally, the elastic connector includes a rod that passes through the piston 512 (with the sealing plate 513 and the magnetic plate 514 fixedly connected at both ends respectively) and a return spring sleeved on the rod (with the piston 512 and the magnetic plate 514 fixedly connected at both ends respectively). Under the action of the elastic connector, the sealing plate 513 tightly seals the through hole in the initial state, preventing NOx exhaust gas from being discharged. An electromagnetic ring 517 is provided on one side of the piston 512. When energized, it attracts the magnetic plate 514 and moves the sealing plate 513 to open the through hole. Specifically, the electromagnetic ring 517 is embedded on the side of the piston 512 away from the NOx discharge pipe 300. When the electromagnetic ring 517 is energized, it attracts the magnetic plate 514, and then moves the sealing plate 513 through the elastic connector. At this time, NOx exhaust gas can be discharged from the through hole. When the electromagnetic ring 517 is closed, the elastic connector drives the sealing plate 513 to reset and reseal the through hole. Contact sensors 515 are provided on both sides of the piston 512. The contact sensors 515 are conventional electrical components in this field and will not be described in detail here. The first processor 509 has protrusions 516 at both ends of its inner cavity for contacting the two contact sensors 515. The piston 512 is also connected to the inner wall of one side of the first processor 509 through an elastic element. Optionally, the elastic element is, for example, a tension spring. When one contact sensor 515 facing the NOx discharge pipe 300 contacts the corresponding protrusion 516, the electromagnetic ring 517 is de-energized; when another contact sensor 515 contacts another protrusion 516, the electromagnetic ring 517 is energized. Both the contact sensors 515 and the electromagnetic ring 517 are electrically connected to the controller. Please refer to the appendix. Figure 5-6In the initial state, a contact sensor 515 on piston 512 facing NOx discharge pipe 300 contacts the corresponding protrusion 516 (left protrusion 516), and electromagnetic ring 517 is de-energized. At this time, NOx exhaust gas is discharged into the first processor 509 from NOx discharge pipe 300. When the exhaust gas pressure reaches a preset threshold, it will push piston 512 to move within the first processor 509. When piston 512 moves and another contact sensor 515 contacts another protrusion 516 (right protrusion 516), the other contact sensor 515 sends a signal to the controller. The controller controls electromagnetic ring 517 to be energized, and electromagnetic ring 517 attracts magnetic plate 514, causing sealing plate 513 to move, thereby releasing NOx from the first processor 509. Exhaust gas flows through the through hole, piston 512, and into the second connecting pipe. As the gas pressure decreases, piston 512 is gradually pulled back to its original position by the elastic element (the electromagnetic ring 517 is energized during the resetting process) until a contact sensor 515 facing the NOx discharge pipe 300 contacts the corresponding protrusion 516, closing the electromagnetic ring 517. It should be noted that the magnetic attraction of the electromagnetic ring 517 is greater than the thrust generated by the gas pressure acting on the sealing plate 513, that is, when the electromagnetic ring 517 is energized, the sealing plate 513 can move against the gas pressure. In this way, the amount of NOx exhaust gas entering the reduction mechanism 500 is effectively limited, and intermittent NOx exhaust gas treatment is achieved, reducing the processing burden of the reduction mechanism 500.
[0020] Please see the appendix Figure 7-8 Preferably, the intake control unit of this embodiment includes a sealing plate 521 inserted into the second processor 510 to seal the inner cavity of the second processor 510. Specifically, the sealing plate 521 is vertically inserted into the top of the second processor 510. A rack 522 (preferably, a groove is formed on the top of the sealing plate 521, the elastic telescopic member is disposed in the groove, and one end of the rack 522 extends into the groove and connects to the elastic telescopic member) is connected to one side of the sealing plate 521 via an elastic telescopic member (such as an elastic telescopic rod). An elastic reset member (such as a spring) connects the rack 522 and the second processor 510. The rack 522 meshes with a toothed gear set 523, which is rotatably mounted on the second processor 510 and connected to the intake control unit via a transmission component. When the intake control unit is activated, the intermittent meshing characteristic of the toothed gear causes the rack 522 to produce intermittent lifting and lowering motion, thereby precisely controlling the opening and closing frequency and opening degree of the sealing plate 521. This achieves intermittent controlled delivery of ammonia fuel in the second processor 510, effectively matching the amount of NOx waste gas supplied by the first processor 509, avoiding waste caused by excessive ammonia fuel input, and affecting the treatment effect of NOx waste gas if too little ammonia fuel input is insufficient.
[0021] Preferably, the transmission component in this embodiment includes a magnetic block 519 slidably disposed within the first processor 509, and a pull rope 520 with one end connected to the magnetic block 519 and the other end wound around the outer wall of the take-up roller. It should be noted that the outer wall of the first processor 509 has an opening for the pull rope 520 to pass through. Of course, the connection between the pull rope 520 and the opening is sealed. The take-up roller is elastically rotatably disposed on the first processor 509. Optionally, the shaft of the take-up roller is rotatably disposed on a bracket by a torsion spring. The bracket is fixedly connected to the first processor 509. The take-up roller and the toothed gear set 523 are connected by a sprocket transmission group, which includes a sprocket and a chain. When another contact sensor 515 contacts another bump 516, the electromagnetic ring 517 is also energized to attract the magnetic block 519. In this way, when the electromagnetic ring 517 is energized, it not only attracts the magnetic plate 514, causing the sealing plate 513 to open the through hole, but also attracts the magnetic block 519. When the elastic element drives the piston 512 to reset, it simultaneously drives the magnetic block 519. The magnetic block 519 pulls the pull rope 520, which in turn pulls the winding roller to rotate (clockwise). The shaft of the winding roller drives the toothed gear set 523 to rotate (clockwise) through the sprocket transmission group. In turn, the toothed gear set 523 and the rack 522 work together to intermittently drive the sealing plates 521 and 513. Lifting; when the electromagnetic ring 517 is de-energized, the winding roller resets under the action of the torsion spring, and the winding rope 520 drives the magnetic block 519 to reset and move. When the winding roller resets and rotates, it drives the toothed gear set 523 to rotate in the opposite direction. Because the rack 522 and the sealing plate 521 are connected by an elastic telescopic component, after the sealing plate 521 is closed, the toothed gear set 523 drives the rack 522 to move downward, which will cause the rack 522 to squeeze the elastic telescopic component so as not to interfere with the rotation and reset of the toothed gear set 523. There will be no situation where the two are stuck and cannot reset.
[0022] Preferably, the first processor 509 of this embodiment is provided with a guide rod 518 parallel to the axis of the piston 512. The guide rod 518 movably passes through the piston 512 and the magnetic block 519. Both the piston 512 and the magnetic block 519 are provided with openings for the guide rod 518 to pass through. A sealing ring can be embedded in the opening to improve the sealing at the connection with the guide rod 518. The provision of the guide rod 518 ensures the stable horizontal movement of the piston 512 and the magnetic block 519.
[0023] Preferably, in this embodiment, the first processor 509 and the second processor 510 are both housed in a protective shell 508. Optionally, the protective shell 508 is connected to the outer wall of the shell 501 by a bracket, and the protective shell 508 serves to protect the first processor 509 and the second processor 510.
[0024] A catalytic reduction method for NOx emissions from an ammonia-fueled engine, utilizing the aforementioned reduction system, includes the following steps: S1: The NOx exhaust gas emitted by the main body 100 of the ammonia fuel engine enters the first processor 509 through the NOx exhaust pipe 300, driving the intake control unit to move. After the NOx exhaust gas drives the unit to a preset position, the intake control unit opens, allowing the NOx exhaust gas to be discharged from the annular pipe 507 into the housing 501 through the second connecting pipe. S2: When the intake control unit opens to discharge NOx exhaust gas, the intake control unit resets and moves to make the intermittent feeding unit work. The ammonia fuel in the ammonia fuel feed pipe 200 enters the second processor 510 through the side feed pipe 400 and then intermittently and controlledly enters the first connecting pipe 511 and is sprayed out from the atomizing nozzle 505. S3: After step S2, ammonia fuel and NOx exhaust gas are mixed in the shell 501 and treated by the SCR catalytic system 504 to be reduced into harmless nitrogen and water. Then, nitrogen and water are discharged from the drain port 502 and the exhaust port 503 respectively.
[0025] Example 2 Please see the appendix Figure 7-8 Based on Embodiment 1, the toothed gear set 523 of this embodiment includes a support base disposed on the second processor 510. The support base is U-shaped, and a shaft part rotatably disposed inside the support base and connected to the sprocket transmission group is slidably disposed on the shaft part. Several sets of toothed gear bodies are connected in sequence. In this embodiment, at least three sets of toothed gear bodies are provided. The three sets of toothed gear bodies are coaxially fixed together in sequence and can move simultaneously on the outer wall of the shaft part. Furthermore, the inner wall of the toothed gear body is provided with a slider, and the outer wall of the shaft part is provided with a groove along its axis that cooperates with the slider, so as not to interfere with the movement of the toothed gear body while allowing it to rotate with the shaft part. One of the toothed gear bodies is rotatably connected to a lever block 525. In this embodiment, the lever block 525 is movably sleeved on the outside of the shaft and rotatably connected to a toothed gear body through a bearing, without interfering with the rotation of the toothed gear body. The lever block 525 is connected to the output end of the telescopic device 524 and is driven by the telescopic device 524 to switch several sets of toothed gear bodies meshing with the rack 522. Optionally, the telescopic device 524 includes an electric telescopic rod or a hydraulic telescopic device, etc. The telescopic device 524 can be installed on the protective shell 508. The arc lengths of the missing tooth segments of several sets of toothed gear bodies increase sequentially (e.g., 30°, 60°, 90°), and the axial length of the toothed gear body is adapted to the width of the rack 522. In this way, since the arc lengths of the missing tooth segments of several sets of toothed gear bodies are different, toothed gear bodies with different arc lengths of missing tooth segments are selected to mesh with the rack 522 by axial sliding. The opening range and duration of the sealing plate 521 are controlled by the difference in the arc length of the missing tooth segments, so as to achieve precise adjustment of the ammonia fuel supply and adapt to the treatment requirements of NOx waste gas with different concentrations. Because the axial length of the toothed gear body is adapted to the width of the rack 522, when one toothed gear body meshes with the rack 522, the adjacent toothed gear bodies will not interfere with the rack 522.
[0026] Preferably, in this embodiment, the NOx discharge pipe 300 is provided with a first pump body 301 and a detection sensor 302 for detecting NOx concentration, and the side feed pipe 400 is provided with a valve body 401 and a second pump body 402. The first pump body 301, the detection sensor 302, the valve body 401, the second pump body 402, the contact sensor 515, and the electromagnetic ring 517 are all electrically connected to the controller. The controller is configured to de-energize the electromagnetic ring 517, open the first pump body 301, and close the valve body 401 and the second pump body 402 when a contact sensor 515 toward the NOx discharge pipe 300 contacts the corresponding protrusion 516, thereby causing the first processor 509 to be filled with a preset amount of NOx exhaust gas; when another contact sensor 515 contacts another protrusion 516, the controller energizes the electromagnetic ring 517, closes the first pump body 301, and opens the valve body 401 and the second pump body 402, thereby allowing ammonia fuel to enter the second processor 510, and NOx exhaust gas no longer enters the first processor 509; Optionally, valve body 401 is a solenoid valve, first pump body 301 and second pump body 402 are booster pumps, and detection sensor 302 is a concentration detection sensor. The concentration detection sensor makes it easier for operators to understand the concentration of NOx exhaust gas, thereby controlling the telescopic device 524 to select the toothed gear body with different toothed arc lengths to mesh with the rack 522, so as to adjust the ammonia fuel supply.
[0027] Example 3 Please see the appendix Figure 9Based on Embodiment 1, in this embodiment, a heat-insulating sleeve 506 is fitted onto the outer wall of the atomizing nozzle 505 and located inside the housing 501. The inner wall of the heat-insulating sleeve 506 is provided with a heat-conducting ring 527 for contacting the outer wall of the atomizing nozzle 505. Preferably, the heat-conducting ring 527 is made of a metal material with a high thermal conductivity. Specifically, in this embodiment, the heat-conducting ring 527 is fitted onto the outside of the nozzle orifice of the atomizing nozzle 505. An annular cavity is formed inside the heat-insulating sleeve 506, and a first friction ring 528 is fixedly installed inside the annular cavity. The first friction ring 528 and the heat-conducting ring 527 are connected by several sets of heat-conducting plates 530. The second friction ring 529 is movably sleeved on the outer wall of the first friction ring 528. The first friction ring 528, the second friction ring 529 and the heat-conducting plates 530 are all made of metal. The outer wall of the second friction ring 529 is provided with several sets of blades 526. The outer wall of the heat-insulating sleeve 506 is connected to the other end of the first processor 509 and the annular pipe 507 through the air inlet pipe and the air outlet pipe, respectively. The air inlet pipe, the air outlet pipe and the second connecting pipe are all provided with control valves (preferably solenoid valves). During the initial start-up phase of the ammonia fuel engine body 100, the control valve in the second connecting pipe can be closed, while the control valves in the intake and exhaust pipes can be opened. When NOx exhaust gas is discharged from the other end of the first processor 509, it does not enter the annular pipe 507 through the second connecting pipe, but first enters the annular cavity through the intake pipe and then enters the annular pipe 507. After entering the annular cavity, the NOx exhaust gas drives the blades 526 to rotate the second friction ring 529 relative to the first friction ring 528, generating frictional heat. The frictional heat and the heat of the NOx exhaust gas are transferred to the heat-conducting ring 527 through the first friction ring 528 and the heat-conducting plate 530. The heat-conducting ring 527 then transfers the heat to the atomizing nozzle 505, effectively preventing the atomizing nozzle 505 from absorbing heat and freezing to block the nozzle hole when spraying ammonia fuel during the initial start-up phase. During normal use, the control valve in the second connecting pipe can be opened, while the control valves in the intake and exhaust pipes can be closed.
[0028] The above embodiments merely illustrate several implementation methods of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention.
Claims
1. A catalytic reduction system for NOx emissions from an ammonia fuel engine, used to treat NOx exhaust gas emitted from the main body (100) of an ammonia fuel engine, wherein the main body (100) of the ammonia fuel engine is connected to an ammonia fuel inlet pipe (200) and a NOx outlet pipe (300), characterized in that, The reduction system includes: a side feed pipe (400) connected at one end to the ammonia fuel feed pipe (200), and a reduction mechanism (500) connecting the side feed pipe (400) and the NOx discharge pipe (300); The reduction mechanism (500) includes a housing (501), a drain port (502) and an exhaust port (503) on the housing (501), an SCR catalytic system (504) inside the housing (501), a first processor (509) and a second processor (510) on the housing (501). One end of the first processor (509) is connected to a NOx discharge pipe (300), and the other end extends into the housing (501) through a second connecting pipe and is connected to an annular pipe (507), which is located above the SCR catalytic system (504). One end of the second processor (510) is connected to a side feed pipe (400). The other end is connected to the atomizing nozzle (505) inserted on the top of the housing (501) through the first connecting pipe (511). The first processor (509) is provided with an air intake control unit. The air intake control unit is driven to move to a preset position by the NOx exhaust gas entering the first processor (509) and then opens to allow the NOx exhaust gas to be discharged from the first processor (509). When the NOx exhaust gas is discharged, it resets and moves to the initial position. The second processor (510) is provided with an intermittent feeding unit. The intermittent feeding unit is connected to the air intake control unit and is used to allow the ammonia fuel entering the second processor (510) to intermittently enter the first connecting pipe (511) when the air intake control unit resets and moves.
2. The restoration system according to claim 1, characterized in that, The intake control unit includes a piston (512) movably disposed within the first processor (509). The piston (512) has a through hole and a sealing plate (513) for closing the through hole. The diameter of the sealing plate (513) is larger than the diameter of the through hole and smaller than the diameter of the piston (512). A magnetic plate (514) is connected to one side of the sealing plate (513) through an elastic connector that passes through the piston (512). An electromagnetic ring (517) is provided on one side of the piston (512) to attract the magnetic plate (514) and drive the sealing plate (513) to move so that the through hole is opened when energized. Contact sensors (515) are provided on both sides of the piston (512). Protrusions (516) for contacting the two contact sensors (515) are provided at both ends of the inner cavity of the first processor (509). The piston (512) is also connected to the inner wall of one side of the first processor (509) through an elastic member. When one contact sensor (515) facing the NOx discharge pipe (300) contacts the corresponding bump (516), the electromagnetic ring (517) is de-energized, and when another contact sensor (515) contacts another bump (516), the electromagnetic ring (517) is energized.
3. The restoration system according to claim 2, characterized in that, The intake control unit includes a sealing plate (521) inserted into the second processor (510) for sealing the inner cavity of the second processor (510), a rack (522) connected to one side of the sealing plate (521) by an elastic telescopic member, an elastic reset member connecting the rack (522) and the second processor (510), and a toothed gear set (523) meshing with the rack (522). The toothed gear set (523) is rotatably mounted on the second processor (510) and is connected to the intake control unit by a transmission member.
4. The restoration system according to claim 3, characterized in that, The transmission component includes a magnetic block (519) slidably disposed in the first processor (509), and a pull rope (520) with one end connected to the magnetic block (519) and the other end wound around the outer wall of the take-up roller. The take-up roller is elastically rotatably disposed on the first processor (509), and the take-up roller and the toothed gear set (523) are connected by a sprocket transmission set. When another contact sensor (515) contacts another bump (516), the electromagnetic ring (517) is also energized to attract the magnetic block (519).
5. The restoration system according to claim 4, characterized in that, The first processor (509) is provided with a guide rod (518) parallel to the axis of the piston (512), and the guide rod (518) moves through the piston (512) and the magnetic block (519).
6. The restoration system according to claim 3, characterized in that, The toothed gear set (523) includes a support base on the second processor (510), a shaft part rotatably connected to the sprocket drive set inside the support base, and several sets of toothed gear bodies slidably on the shaft part. The several sets of toothed gear bodies are connected in sequence, and a toggle block (525) is rotatably connected to one side of one toothed gear body. The toggle block (525) is connected to the output end of the telescopic device (524) and is driven by the telescopic device (524) to switch the engagement of several sets of toothed gear bodies with the rack (522). The arc length of the missing tooth segment of several sets of missing tooth gear bodies increases sequentially, and the axial length of the missing tooth gear body is adapted to the width of the rack (522).
7. The restoration system according to claim 3, characterized in that, The NOx discharge pipe (300) is provided with a first pump body (301) and a detection sensor (302) for detecting NOx concentration. The side feed pipe (400) is provided with a valve body (401) and a second pump body (402). The first pump body (301), the detection sensor (302), the valve body (401), the second pump body (402), the contact sensor (515), and the electromagnetic ring (517) are all electrically connected to the controller. The controller is configured to de-energize the electromagnetic ring (517), open the first pump body (301), and close the valve body (401) and the second pump body (402) when a contact sensor (515) toward the NOx discharge pipe (300) contacts the corresponding protrusion (516); and to energize the electromagnetic ring (517), close the first pump body (301), and open the valve body (401) and the second pump body (402) when another contact sensor (515) contacts another protrusion (516).
8. The restoration system according to claim 1, characterized in that, A heat-insulating sleeve (506) is fitted on the outer wall of the atomizing nozzle (505) and located inside the housing (501). The inner wall of the heat-insulating sleeve (506) is provided with a heat-conducting ring (527) for contacting the outer wall of the atomizing nozzle (505). An annular cavity is opened inside the heat-insulating sleeve (506). A first friction ring (528) is fixedly installed in the annular cavity. The first friction ring (528) and the heat-conducting ring (527) are connected by a number of heat-conducting plates (530). A second friction ring (529) is movably fitted on the outer wall of the first friction ring (528). A number of blades (526) are provided on the outer wall of the second friction ring (529). The outer wall of the heat-insulating sleeve (506) is connected to the other end of the first processor (509) and the annular pipe (507) through an air inlet pipe and an air outlet pipe, respectively. Control valves are provided in the air inlet pipe, the air outlet pipe and the second connecting pipe.
9. The restoration system according to claim 1, characterized in that, The first processor (509) and the second processor (510) are both housed within a protective casing (508).
10. A method for catalytic reduction of NOx emissions from an ammonia-fueled engine, utilizing the reduction system as described in any one of claims 1-9, characterized in that: Includes the following steps: S1: The NOx exhaust gas emitted by the main body (100) of the ammonia fuel engine enters the first processor (509) through the NOx exhaust pipe (300) to drive the intake control unit to move. After the NOx exhaust gas drives the unit to move to the preset position, the intake control unit opens so that the NOx exhaust gas is discharged from the annular pipe (507) to the housing (501) through the second connecting pipe. S2: When the intake control unit opens to discharge NOx exhaust gas, the intake control unit resets and moves to make the intermittent feeding unit work. The ammonia fuel in the ammonia fuel feed pipe (200) enters the second processor (510) through the side feed pipe (400) and then intermittently and controlledly enters the first connecting pipe (511) and is sprayed out from the atomizing nozzle (505). S3: After step S2, ammonia fuel and NOx exhaust gas are mixed in the shell (501) and treated by the SCR catalytic system (504) to be reduced into harmless nitrogen and water. Then, nitrogen and water are discharged from the drain port (502) and exhaust port (503) respectively.