A ship diesel engine post-processing ultrasonic fuel atomization regeneration system and method

Abstract

The present application relates to a kind of ship diesel engine post-processing ultrasonic fuel atomization regeneration system and method, including ultrasonic atomizer, oil supply system, pipeline system, atomization mixing chamber, post-processing system and control system.Control system is integrated by ECU control.Ultrasonic atomizer can atomize diesel into small particle size flammable vapor, improve combustion efficiency and reduce emission.Ship diesel engine is by catalytic oxidation device DOC and the post-processing system of particle trap DPF, DPF needs regeneration, opens post-processing system intake exhaust control valve, mixes exhaust gas with diesel vapor, occurs catalytic reaction in DOC and releases heat, for improving DPF reaction bed temperature, and ignites the particulate matter stored, realizes DPF regeneration.Regeneration system flexible design, can use ship diesel or connect independent oil tank, wide applicability.The present application is environmental protection high efficiency, high efficient and reliable, easy to use, provides innovative solution for ship diesel engine emission control.

Description

Technical Field

[0001] This invention relates to the field of diesel engine emission pollutant treatment technology, and more particularly to an ultrasonic fuel atomization regeneration system and method for marine diesel engine aftertreatment. Background Technology

[0002] Ship particulate matter emissions cause serious pollution to the coastal environment, and particulate matter emission control is an important aspect of controlling pollutants from ship diesel engines. The diesel particulate filter (DPF) is currently recognized as an effective device for reducing particulate matter (PM) emissions. When diesel fuel burns in the cylinder, it produces PM that pollutes the atmosphere. This PM is captured and deposited in the DPF. When the deposited PM exceeds a certain amount, it can clog the exhaust pipe, affecting the diesel engine's power. Removing the PM accumulated in the DPF channels and restoring its capturing capacity is called DPF regeneration.

[0003] To increase the regeneration temperature within the DPF (Digital Fluid Power Generation) system, a diesel engine catalytic oxidation (DOC) device is typically used to assist in DPF regeneration. The DOC surface is coated with a precious metal catalyst. When the DOC exhaust temperature exceeds 300 degrees Celsius, unburned hydrocarbons are injected into the DOC via diesel fuel or post-injection into the engine cylinder. This unburned material undergoes an exothermic oxidation reaction within the DOC, providing the heat needed to heat the exhaust and regenerate the DPF. A catalyst-coated DPF temperature above 300 degrees Celsius is required to ignite PM (particulate matter) deposited within it. Due to the low exhaust temperature of marine diesel engines, experimental DPF regeneration is difficult. Summary of the Invention

[0004] In response to the aforementioned technical problems, a marine diesel engine aftertreatment ultrasonic fuel atomization regeneration system and method are provided.

[0005] The technical means employed in this invention are as follows:

[0006] An ultrasonic fuel atomization and regeneration system for marine diesel engine aftertreatment includes an ultrasonic atomizer, a fuel supply system, a piping system, an atomization mixing chamber, a catalytic oxidation unit (DOC), a particulate filter (DPF), a temperature sensor, a differential pressure sensor, a particulate matter concentration sensor, a humidity sensor, an electronic control unit (ECU), an intake control valve, and an exhaust control valve, wherein:

[0007] The ultrasonic atomizer is disposed in the atomization mixing chamber, and the ultrasonic atomizer is used to atomize diesel fuel.

[0008] The output end of the fuel supply system is connected to the atomizing mixing chamber and is used to supply diesel fuel into the atomizing mixing chamber;

[0009] The atomizing mixing chamber is located on the main pipeline upstream of the catalytic oxidation unit DOC, and the intake control valve and exhaust control valve are installed between the two.

[0010] The output of the catalytic oxidation device DOC is connected to the particulate filter DPF. The catalytic oxidation device DOC is used to catalytically react the gas mixture of exhaust gas and diesel vapor and release heat. The particulate filter DPF is used to collect particulate matter from the marine diesel engine.

[0011] The temperature sensor is used to measure the temperature information at preset points on the main pipeline. The differential pressure sensor is used to measure the exhaust back pressure of the particulate filter (DPF). The particulate concentration sensor is used to monitor the concentration of particulate matter discharged from the DPF. The humidity sensor is located at the top inside the ultrasonic atomizer and is used to monitor the concentration of the atomized mixed gas in the atomization mixing chamber. All of the above sensors are connected to the electronic control unit (ECU). The ECU is connected to the intake control valve and the exhaust control valve and controls the opening state of the intake control valve and the exhaust control valve based on the data transmitted by the sensors.

[0012] Furthermore, the ultrasonic atomizer is made of a miniature piezoelectric vibrating plate, which generates ultrasonic waves by contacting diesel fuel. The ultrasonic waves atomize the diesel fuel into even smaller droplets, thereby achieving diesel fuel atomization.

[0013] Furthermore, the ultrasonic atomizer employs an ultrasonic generator with an oscillation frequency of 110kHz±3kHz. Its structure includes several atomization units, an ultrasonic generator, and an atomizer control device. Each atomization unit consists of multiple microporous atomizing plates, which are composed of piezoelectric ceramics and metal films. Their surfaces have minute textures, and the central part contains a microporous structure. The number of ultrasonic atomization units that are activated can be controlled. The ultrasonic generator, as a device that provides high-frequency electrical energy, is used to drive the ultrasonic vibrating plates in the atomizer. The ultrasonic atomization diesel control device is controlled by an electronic control unit (ECU) to adjust the operating frequency of the ultrasonic generator, the electrical energy output, and the number of activations of the control unit.

[0014] Furthermore, the fuel supply system includes a fuel tank, a fuel filter, a fuel pump, a fuel shut-off solenoid valve, and a level control sensor in the atomizing mixing chamber. The fuel pump controls the fuel shut-off solenoid valve to allow diesel fuel in the fuel tank to flow through the fuel filter and into the atomizing mixing chamber. The level control sensor is connected to the electronic control unit (ECU). Based on the data provided by the level control sensor, the output state of the fuel supply system is controlled to ensure the supply of diesel fuel and the ratio of diesel fuel vapor to the mixture. There is a drain plug at the bottom of the atomizing mixing chamber.

[0015] Furthermore, the temperature sensor specifically includes a first temperature sensor, a second temperature sensor, and a third temperature sensor, wherein the first temperature sensor is used to measure the DOC inlet temperature of the catalytic oxidation unit, the second temperature sensor is used to measure the DPF inlet temperature of the particulate filter, and the third temperature sensor is used to measure the DPF outlet temperature of the particulate filter.

[0016] Furthermore, the diesel fuel in the fuel supply system can be sourced from a fuel supply system directly connected to the ship or from a separate fuel tank.

[0017] Furthermore, the catalytic oxidation device (DOC) includes a shell, a ceramic gasket, a catalyst support, and a precious metal catalyst coated on the surface of the support. The particulate filter (DPF) consists of a shell, a ceramic gasket, and a honeycomb filter. When the DPF needs regeneration, the electronic control unit (ECU) controls the opening of the intake control valve and the exhaust control valve. Some of the exhaust gas flows into the atomizing mixing chamber, mixes with diesel vapor, and flows out, merging with the mainstream exhaust gas and entering the DOC for combustion. This increases the temperature of the DPF reaction bed, ignites the stored particulate matter, and achieves DPF regeneration.

[0018] The present invention also provides a method based on the above-mentioned ultrasonic fuel atomization regeneration system for marine diesel engine aftertreatment, comprising the following steps:

[0019] Exhaust gas enters the ultrasonic fuel atomization and regeneration system of the marine diesel engine through the air inlet and the gas pipeline. The temperature at the DOC inlet of the catalytic oxidation device is measured by the first temperature sensor. The electronic control unit (ECU) monitors and provides feedback on the data in real time to determine whether to implement the regeneration system control strategy.

[0020] If a regeneration system control strategy is required, the electronic control unit (ECU) opens the inlet control valve, allowing exhaust gas to enter the atomization mixing chamber. The ECU also controls the fuel shut-off solenoid valve to open and the fuel pump to pump diesel fuel from the tank. The diesel fuel flows through the fuel filter into the atomization mixing chamber. The ECU then controls the ultrasonic atomizer to atomize the diesel fuel into fuel vapor, which mixes with the exhaust gas flowing into the atomization mixing chamber, increasing the temperature of the mixed vapor. This vapor then enters the catalytic oxidation unit (DOC) through the exhaust control valve, completing the regeneration process.

[0021] Based on the real-time data monitored and fed back by the electronic control unit (ECU) and the first temperature sensor, second temperature sensor, third temperature sensor, differential pressure sensor, particulate matter concentration sensor, humidity sensor, and liquid level control sensor, the regeneration system control strategy is implemented, and the above steps are repeated to treat the exhaust gas until the treated exhaust gas is discharged from the exhaust port.

[0022] Furthermore, the electronic control unit (ECU) collects the exhaust pressure difference P measured by the differential pressure sensor and the collection operation time t of the particulate filter (DPF) in real time, and compares the collected exhaust pressure difference P and collection operation time t with the set upper limit values ​​Pmax and tmax to determine whether the upper limit values ​​are exceeded.

[0023] If the exhaust pressure difference P is greater than the set upper limit Pmax or the time t is greater than the set upper limit tmax, it indicates that the particulate filter DPF needs to be regenerated; if neither the exhaust pressure difference P nor the time t reaches the upper limit, the DPF does not need to be regenerated. After regeneration, the time t is reset and the exhaust pressure difference is measured again.

[0024] Furthermore, the temperature T1 at the DOC inlet of the catalytic oxidation unit is measured by a first temperature sensor; the temperature T2 at the DPF inlet of the particulate filter is measured by a second temperature sensor; and the temperature T3 at the DPF outlet of the particulate filter is measured by a third temperature sensor. When temperature T1 is below 300°C, the engine employs in-cylinder heating and exhaust gas recirculation to raise the exhaust pipe temperature to 300°C, thereby fully activating the DOC conversion efficiency of the catalytic oxidation unit. When temperature T1 is above 300°C, the inlet and outlet control valves are opened to atomize the fuel in the atomization mixing chamber, increasing the exhaust temperature through combustion. When temperature T2 is below the critical temperature Tcr, the ECU controls the operating frequency and power output of the ultrasonic atomizer to control the concentration of the fuel atomized mixture. When temperature T2 is above the critical temperature Tcr, the inlet and outlet control valves and the ultrasonic atomizer are closed, and fuel supply is stopped via the fuel shut-off solenoid valve. When temperature T3 is above the safe temperature threshold Tsafe of the DPF, the ECU issues a fault signal.

[0025] Compared with the prior art, the present invention has the following advantages:

[0026] This invention employs an ultrasonic atomizer that utilizes high-frequency electronic oscillations and the high-frequency resonance of a ceramic atomizing plate to atomize liquid diesel molecules into tiny particles. A key component of the ultrasonic atomization unit is the atomizing plate, which utilizes the piezoelectric atomization principle to atomize diesel fuel. Piezoelectric atomization refers to the process where, when an electric current is applied to the atomizing plate, the inverse piezoelectric effect is used to convert the electrical energy into mechanical energy, causing the liquid diesel fuel to vigorously move. The vibration of the liquid generates inertia, which is then converted into kinetic energy. Once the kinetic energy reaches a certain critical point, cavitation occurs, achieving the atomization of the liquid diesel fuel.

[0027] The marine diesel engine aftertreatment system consists of a diesel engine catalytic oxidation unit (DOC) and a diesel particulate filter (DPF). When the DPF needs to be regenerated, the intake and exhaust control valves of the aftertreatment system are opened to mix the exhaust gas with diesel vapor. A catalytic reaction occurs in the DOC, releasing heat and raising the temperature of the DPF reaction bed to ignite the stored particulate matter, thus achieving DPF regeneration. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of the diesel engine exhaust aftertreatment system of the present invention.

[0030] Figure 2 This is a schematic flowchart of the control method for regenerating the particle trap according to the present invention.

[0031] In the diagram: 1. Electronic Control Unit (ECU); 2. Catalytic Oxidation Unit (DOC); 3. Particulate Filter (DPF); 4. First Temperature Sensor; 5. Second Temperature Sensor; 6. Differential Pressure Sensor; 7. Third Temperature Sensor; 8. Particulate Matter Concentration Sensor; 9. Humidity Sensor; 10. Liquid Level Control Sensor; 11. Atomizing Mixing Chamber; 12. Ultrasonic Atomizer; 13. Drain Bolt; 14. Fuel Tank; 15. Fuel Filter; 16. Fuel Pump; 17. Fuel Shut-off Solenoid Valve; 18. Intake Control Valve; 19. Exhaust Control Valve; 20. Intake Port; 21. Air Supply Pipeline; 22. Exhaust Port. Detailed Implementation

[0032] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0033] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0035] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0036] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention. The directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0037] For ease of description, spatial relative terms such as "above," "over," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation besides the orientation of the device as described in the figures. For example, if the device in the figures is inverted, a device described as "above" or "above" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0038] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0039] like Figure 1 As shown in the figure, this invention discloses an ultrasonic fuel atomization regeneration system for marine diesel engine aftertreatment, including an ultrasonic atomizer 12, a fuel supply system, a piping system, an atomization mixing chamber 11, a catalytic oxidation device (DOC) 2, a particulate filter (DPF) 3, a first temperature sensor 4, a second temperature sensor 5, a third temperature sensor 7, a differential pressure sensor 6, a particulate matter concentration sensor 8, a humidity sensor 9, a liquid level control sensor 10, an electronic control unit (ECU) 1, an intake control valve 18, and an exhaust control valve 19, wherein:

[0040] The ultrasonic atomizer 12 is made of a miniature piezoelectric vibrating plate, which generates ultrasonic waves by contacting diesel fuel. The ultrasonic waves atomize the diesel fuel into even smaller droplets, thus achieving diesel fuel atomization. It is located inside the atomization mixing chamber 11.

[0041] The fuel supply system consists of a fuel tank 14, a fuel filter 15, a fuel pump 16, a fuel shut-off solenoid valve 17, and a liquid level control sensor 10 in the atomizing mixing chamber 11. The fuel pump 16 controls the fuel shut-off solenoid valve 17 to allow diesel fuel in the fuel tank 14 to flow through the fuel filter 15 and into the atomizing mixing chamber 11. The liquid level control sensor 10 in the atomizing mixing chamber 11 can control the amount of fuel entering the system, ensuring the supply of diesel fuel and the ratio of diesel fuel vapor to the mixture, thereby ensuring the normal operation of the system.

[0042] The pipeline system consists of an air inlet 20, an air delivery pipeline 21, an exhaust port 22, and connecting pipelines for DOC2 and DPF3. The first half of the air delivery pipeline 21 is defined as the main pipeline connected to the atomizing mixing chamber 11.

[0043] The atomizing mixing chamber 11 is located upstream of DOC2, and its connection to DOC2 is achieved through an intake control valve 18 and an exhaust control valve 19. The atomizing mixing chamber 11 contains an ultrasonic atomizer 12 and a liquid level control sensor 10. At the bottom of the atomizing mixing chamber 11 is a drain plug 13. When there is excessive suspended matter, impurities, or moisture, these impurities will accumulate at the bottom of the tank, periodically draining the impurities to maintain the normal operation and performance of the atomizer.

[0044] The DOC2 mainly consists of a shell, a ceramic gasket, a catalyst carrier, and a precious metal catalyst coated on the surface of the carrier. The exhaust gas mixed with diesel vapor undergoes a catalytic reaction in the DOC, releasing heat and thus increasing the temperature of the DPF reaction bed. The DPF3, composed of a shell, a ceramic gasket, and a honeycomb filter, can capture particulate matter from the marine diesel engine, reducing particulate emissions. When DPF3 needs regeneration, the intake control valve 18 and exhaust control valve 19 can be opened, allowing exhaust gas to flow into the atomizing mixing chamber 11. The mixed diesel vapor flows out and merges with the mainstream exhaust gas, entering the DOC2 together to undergo a catalytic reaction and release heat, increasing the temperature of the DPF reaction bed and igniting the stored particulate matter, thus achieving DPF regeneration.

[0045] The ultrasonic fuel atomization regeneration control system for marine diesel engines is integrated with the electronic control unit ECU1 and connected to the first temperature sensor 4, the second temperature sensor 5, the third temperature sensor 7, the differential pressure sensor 6, the particulate matter concentration sensor 8, the humidity sensor 9, and the liquid level control sensor 10 via wires. The system monitors and provides feedback on the data generated by the sensors in real time, thereby achieving precise control and high efficiency.

[0046] The sensors include a first temperature sensor 4, a second temperature sensor 5, a third temperature sensor 7, a differential pressure sensor 6, a particulate matter concentration sensor 8, a humidity sensor 9, and a liquid level control sensor 10. The first temperature sensor 4 measures the inlet temperature of DOC2, the second temperature sensor 5 measures the inlet temperature of DPF3, the third temperature sensor 7 measures the outlet temperature of DPF3, the differential pressure sensor 6 measures the exhaust back pressure of DPF3, the particulate matter concentration sensor 8 monitors the concentration of particulate matter discharged from DPF3, and the humidity sensor 9, located at the top of the ultrasonic atomizer, monitors the concentration of the atomized mixed gas in the atomization mixing chamber 11. Higher humidity indicates more atomized fuel vapor, ensuring the gas concentration entering the DOC for oxidation and regeneration is within a suitable range. The liquid level control sensor 10 monitors the liquid level, and the control unit adjusts the liquid level in real time to maintain it within a reasonable range, ensuring the supply of diesel fuel and the ratio of mixed diesel vapor, thereby guaranteeing the normal operation of the system.

[0047] The ultrasonic atomizer 12 employs an ultrasonic generator with an oscillation frequency of 110kHz ± 3kHz. Its structure comprises four atomizing units and an atomizer control unit. Each atomizing unit consists of two microporous atomizing plates, which are constructed from piezoelectric ceramics and a metal diaphragm. The surface of the microporous atomizing plate has minute textures, and the central portion contains micropores. When a voltage is applied to the vibrating plate, the electric field effect causes the piezoelectric ceramics to produce a piezoelectric effect, thereby causing the vibrating plate to rapidly vibrate mechanically in the longitudinal direction, primarily along its thickness. When the vibrating plate contacts diesel fuel, the mechanical vibration directly disperses the diesel fuel into tiny droplets. The atomization capacity of a single atomizing plate is approximately 100 ml / h. An ultrasonic atomizing unit consists of three atomizing plates, therefore the maximum atomization capacity of one unit is approximately 300 ml / h. The number of ultrasonic atomizing units that are activated can be controlled to achieve consistency in the ultrasonic atomizing generator and facilitate easy maintenance of the ultrasonic atomizing units or generator. An ultrasonic generator, acting as a device to provide high-frequency electrical energy, is used to drive the ultrasonic vibrating plate in the atomizer. The ultrasonic generator produces a high-frequency signal that matches the atomizer and transmits it to the vibrating plate within the atomizer. The ultrasonic atomizing diesel fuel control unit is controlled by ECU1, which adjusts the operating frequency and electrical output of the ultrasonic generator in real time according to the actual conditions during regeneration, and also adjusts the number of control units activated.

[0048] The diesel fuel in the fuel supply system can be directly connected to the ship's fuel supply system, or it can be stored in a separate fuel tank.

[0049] like Figure 2 As shown, the process of the ultrasonic fuel atomization regeneration system for marine diesel engines is as follows:

[0050] Exhaust gas enters the ultrasonic fuel atomization and regeneration system of the marine diesel engine through the air inlet 20 and the air supply pipeline 21. The first temperature sensor 4 before DOC2 measures the temperature at the DOC2 inlet. The ECU1 performs real-time data monitoring and feedback to determine whether to implement the regeneration system control strategy.

[0051] When the inlet control valve is opened, the exhaust gas enters the atomization mixing chamber 11 through the inlet control valve 18. The fuel shut-off solenoid valve 17 is opened, and the fuel pump 16 pumps the diesel fuel from the fuel tank 14. The diesel fuel flows through the fuel filter 15 and into the atomization mixing chamber 11. The ultrasonic atomizer 12 operates, atomizing the diesel fuel into fuel vapor, which mixes with the exhaust gas flowing into the atomization mixing chamber 11, increasing the temperature of the mixed vapor. The mixture then enters the DOC2 through the exhaust control valve 19, completing the regeneration process.

[0052] Based on the real-time data monitored and fed back by ECU1 and the first temperature sensor 4, the second temperature sensor 5, the third temperature sensor 7, the differential pressure sensor 6, the particulate matter concentration sensor 8, the humidity sensor 9, and the liquid level control sensor 10, the regeneration system control strategy is implemented, and the above steps are repeated to treat the exhaust gas until the treated exhaust gas is discharged from the exhaust port 22.

[0053] The aforementioned regeneration demand judgment and control strategy includes the following steps:

[0054] ECU1 collects the exhaust pressure difference P and DPF trapping time t measured by the differential pressure sensor in real time, and compares the collected exhaust pressure difference P and trapping time t with the set upper limit values ​​Pmax and tmax to determine whether the upper limit values ​​are exceeded.

[0055] If the exhaust pressure difference P is greater than the set upper limit Pmax or the time t is greater than the set upper limit tmax, the DPF needs to be regenerated; if neither the exhaust pressure difference P nor the time t reaches the upper limit, the DPF does not need to be regenerated. After regeneration, the time t is reset and the exhaust pressure difference is measured again.

[0056] The foregoing has only described certain exemplary embodiments of the present invention by way of illustration. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the foregoing drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

[0057] Please combine Figure 2 As shown, the control strategy of the ultrasonic fuel atomization regeneration system for marine diesel engines of the present invention includes the following steps:

[0058] The temperature T1 at the DOC2 inlet is measured by the first temperature sensor 4 before DOC2; the temperature T2 at the DPF3 inlet is measured by the second temperature sensor 5 before DPF3; and the temperature T3 at the DPF3 outlet is measured by the third temperature sensor 7 after DPF3. When temperature T1 is below 300°C, the engine employs in-cylinder heating and exhaust gas recirculation to raise the exhaust pipe temperature to 300°C, thereby fully activating the conversion efficiency of DOC2. When temperature T1 is above 300°C, the inlet and outlet control valves are opened to atomize the fuel in the atomization mixing chamber, increasing the exhaust temperature through combustion. When temperature T2 is below the critical temperature Tcr, the operating frequency and electrical output of the ultrasonic atomizer 12 are controlled to regulate the concentration of the fuel atomized mixture. When temperature T2 is above the critical temperature Tcr, the inlet and outlet control valves and the ultrasonic atomizer are closed, and fuel supply is stopped via the fuel shut-off solenoid valve. When temperature T3 exceeds the safe temperature threshold Tsafe of the DPF, the ECU1 issues a fault signal.

[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A marine diesel engine aftertreatment ultrasonic fuel atomization and regeneration system, characterized in that, This includes an ultrasonic atomizer, fuel supply system, piping system, atomizing mixing chamber, catalytic oxidation unit (DOC), particulate filter (DPF), temperature sensor, differential pressure sensor, particulate matter concentration sensor, humidity sensor, electronic control unit (ECU), intake control valve, and exhaust control valve, among which: The ultrasonic atomizer is disposed in the atomization mixing chamber, and the ultrasonic atomizer is used to atomize diesel fuel. The output end of the fuel supply system is connected to the atomizing mixing chamber and is used to supply diesel fuel into the atomizing mixing chamber; The atomizing mixing chamber is located on the main pipeline upstream of the catalytic oxidation unit DOC, and the intake control valve and exhaust control valve are installed between the two. The catalytic oxidation device (DOC) includes a shell, a ceramic gasket, a catalyst support, and a precious metal catalyst coated on the surface of the support. The particulate filter (DPF) consists of a shell, a ceramic gasket, and a honeycomb filter. When the DPF needs to be regenerated, the electronic control unit (ECU) controls the opening of the intake control valve and the exhaust control valve. Some of the exhaust gas flows into the atomizing mixing chamber, mixes with diesel vapor, and flows out, merging with the mainstream exhaust gas and entering the DOC for combustion. This increases the temperature of the DPF reaction bed and ignites the stored particulate matter, thus regenerating the DPF. The output of the catalytic oxidation device DOC is connected to the particulate filter DPF. The catalytic oxidation device DOC is used to catalytically react the gas mixture of exhaust gas and diesel vapor and release heat. The particulate filter DPF is used to collect particulate matter from the marine diesel engine. The temperature sensor is used to measure the temperature information at preset points on the main pipeline; the differential pressure sensor is used to measure the back pressure of the DPF exhaust gas from the particulate filter; the particulate concentration sensor is used to monitor the concentration of particulate matter discharged from the DPF; and the humidity sensor is located at the top of the ultrasonic atomizer to monitor the concentration of the atomized mixed gas in the atomization mixing chamber. All of the above sensors are connected to the electronic control unit (ECU), which is connected to the intake control valve and the exhaust control valve. Based on the data transmitted by the sensors, the ECU controls the opening state of the intake control valve and the exhaust control valve. Specifically, the exhaust gas enters the ultrasonic fuel atomization regeneration system of the marine diesel engine through the air inlet and the gas pipeline. The temperature at the DOC inlet of the catalytic oxidation device is measured by the first temperature sensor. The electronic control unit (ECU) monitors and provides feedback on the data in real time to determine whether to implement the regeneration system control strategy. If a regeneration system control strategy is required, the electronic control unit (ECU) opens the inlet control valve, allowing exhaust gas to enter the atomization mixing chamber. The ECU also controls the fuel shut-off solenoid valve to open and the fuel pump to pump diesel fuel from the tank. The diesel fuel flows through the fuel filter into the atomization mixing chamber. The ECU then controls the ultrasonic atomizer to atomize the diesel fuel into fuel vapor, which mixes with the exhaust gas flowing into the atomization mixing chamber, increasing the temperature of the mixed vapor. This vapor then enters the catalytic oxidation unit (DOC) through the exhaust control valve, completing the regeneration process. Based on the real-time data monitored and fed back by the electronic control unit (ECU) and the first temperature sensor, second temperature sensor, third temperature sensor, differential pressure sensor, particulate matter concentration sensor, humidity sensor, and liquid level control sensor, the regeneration system control strategy is implemented, and the above steps are repeated to treat the exhaust gas until the treated exhaust gas is discharged from the exhaust port. The engine measures the following temperature parameters: First temperature sensor measures the DOC inlet temperature (T1); second temperature sensor measures the DPF inlet temperature (T2); third temperature sensor measures the DPF outlet temperature (T3). When T1 is below 300°C, the engine employs in-cylinder heating and exhaust gas recirculation to raise the exhaust pipe temperature to 300°C, thus fully activating the DOC conversion efficiency. When T1 is above 300°C, the inlet and outlet control valves are opened to atomize the fuel in the atomization mixing chamber, increasing the exhaust temperature through combustion. When T2 is below the critical temperature (Tcr), the ECU controls the operating frequency and power output of the ultrasonic atomizer to control the concentration of the fuel-atomized mixture. When T2 is above the critical temperature (Tcr), the inlet and outlet control valves and the ultrasonic atomizer are closed, and fuel supply is stopped via the fuel shut-off solenoid valve. When T3 is above the safe temperature threshold (Tsafe) of the DPF, the ECU issues a fault signal.

2. The ultrasonic fuel atomization and regeneration system for marine diesel engine aftertreatment according to claim 1, characterized in that, The ultrasonic atomizer is made of a miniature piezoelectric vibrating plate, which generates ultrasonic waves by contacting diesel fuel. The ultrasonic waves atomize the diesel fuel into even smaller droplets, thus achieving diesel fuel atomization.

3. The ultrasonic fuel atomization and regeneration system for marine diesel engine aftertreatment according to claim 1, characterized in that, The ultrasonic atomizer employs an ultrasonic generator with an oscillation frequency of 110kHz±3kHz. Its structure includes several atomization units, an ultrasonic generator, and an atomizer control device. Each atomization unit consists of multiple microporous atomizing plates, which are constructed from piezoelectric ceramics and metal diaphragms. The surface of each microporous atomizing plate has minute textured surfaces, and the central portion contains micropores. The number of ultrasonic atomization units that are activated can be controlled. The ultrasonic generator, as a device providing high-frequency electrical energy, drives the ultrasonic vibrating plates in the atomizer. The ultrasonic atomization diesel fuel control device is controlled by an electronic control unit (ECU), which adjusts the operating frequency of the ultrasonic generator, the electrical output, and the number of activated ECU units.

4. The ultrasonic fuel atomization and regeneration system for marine diesel engine aftertreatment according to claim 1, characterized in that, The fuel supply system includes a fuel tank, a fuel filter, a fuel pump, a fuel shut-off solenoid valve, and a level control sensor in the atomizing mixing chamber. The fuel pump controls the fuel shut-off solenoid valve to allow diesel fuel in the fuel tank to flow through the fuel filter and into the atomizing mixing chamber. The level control sensor is connected to the electronic control unit (ECU). Based on the data provided by the level control sensor, the output state of the fuel supply system is controlled to ensure the supply of diesel fuel and the ratio of diesel fuel vapor to the mixture. There is a drain plug at the bottom of the atomizing mixing chamber.

5. The ultrasonic fuel atomization and regeneration system for marine diesel engine aftertreatment according to claim 1, characterized in that, The temperature sensor specifically includes a first temperature sensor, a second temperature sensor, and a third temperature sensor. The first temperature sensor is used to measure the DOC inlet temperature of the catalytic oxidation unit, the second temperature sensor is used to measure the DPF inlet temperature of the particulate filter, and the third temperature sensor is used to measure the DPF outlet temperature of the particulate filter.

6. The ultrasonic fuel atomization and regeneration system for marine diesel engine aftertreatment according to claim 1, characterized in that, The diesel fuel in the fuel supply system can be sourced from either a fuel supply system directly connected to the ship or from a separate fuel tank.

7. The ultrasonic fuel atomization and regeneration system for marine diesel engine aftertreatment according to claim 1, characterized in that, The electronic control unit (ECU) collects the exhaust pressure difference P measured by the differential pressure sensor and the capture operation time t of the particulate filter (DPF) in real time. It then compares the collected exhaust pressure difference P and capture operation time t with the set upper limit values ​​Pmax and tmax to determine whether the upper limit values ​​are exceeded. If the exhaust pressure difference P is greater than the set upper limit Pmax or the time t is greater than the set upper limit tmax, it indicates that the particulate filter DPF needs to be regenerated. If neither the exhaust pressure difference P nor the time t reaches the upper limit, the particulate filter DPF does not need to be regenerated. After regeneration, the time t is reset and the exhaust pressure difference is measured again.

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