Ammonia fuel combustion system and control method thereof

Abstract

The present invention discloses an ammonia fuel combustion system and a control method thereof, which relate to the field of fuel combustion technology. The system includes an ammonia engine, a reforming hydrogen production device, a preheating box, an ammonia storage, a premixer and a turbocharger, and the reforming hydrogen production device includes a reaction chamber and a heating outer chamber. The premixer mixes the gases from the ammonia storage, the turbocharger and the reaction chamber of the reforming hydrogen production device. The reaction chamber of the reforming hydrogen production device decomposes the ammonia-containing gas from the ammonia storage and the turbocharger to obtain hydrogen-containing gas, and provides the hydrogen-containing gas to the premixer. The exhaust gas outlet of the ammonia engine is connected to the heating outer chamber of the reforming hydrogen production device, and the heating outer chamber provides reaction heat for the reaction chamber. The heating outer chamber is connected to the preheating box, which uses the exhaust gas of the ammonia engine from the heating outer chamber to preheat the ammonia-containing gas input into the reaction chamber. The present application can improve the hydrogen production efficiency, thereby improving the engine operating performance.

Description

Technical Field

[0001] The present invention relates to the technical field of fuel combustion, and in particular to an ammonia fuel combustion system and a control method thereof. Background Art

[0002] Currently, the most widely used marine engine fuels are mainly diesel and natural gas. At the same time, in order to improve energy utilization and reduce pollutant emissions, ammonia is widely used as a zero-carbon fuel. However, at present, the disadvantage of pure ammonia engines is that they cannot maintain stable operation. Therefore, their operating characteristics can be changed by hydrogen-blended combustion to achieve the required energy output. Hydrogen is generally stored in cylinders at high pressure, but this storage method may cause problems such as corrosion and leakage. In comparison, the storage of ammonia is safer and more economical. Therefore, ammonia can be used as a hydrogen-carrying gas and hydrogen-blended combustion can be performed through online hydrogen production to improve the operation and ignition problems of ammonia engines. At present, the devices that use ammonia as a hydrogen-carrying substance to perform thermal catalytic decomposition to prepare fuel hydrogen generally have low heat exchange efficiency, resulting in low hydrogen output and an inability to effectively improve the operating performance of ammonia engines. Summary of the Invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides an ammonia fuel combustion system and a control method thereof, which can improve hydrogen production efficiency and thus improve engine operating performance.

[0004] In one aspect, an embodiment of the present invention provides an ammonia fuel combustion system, comprising: an ammonia engine, a reforming hydrogen production device, a preheating tank, an ammonia storage, a premixer, and a turbocharger, wherein the reforming hydrogen production device comprises a reaction inner chamber and a heating outer chamber;

[0005] The ammonia storage, the turbocharger, and the reaction chamber of the reforming hydrogen production device are all connected to the premixer through pipelines, and the premixer is connected to the feed port of the ammonia engine through a pipeline. The premixer is used to mix the gases from the ammonia storage, the turbocharger, and the reaction chamber of the reforming hydrogen production device;

[0006] The ammonia storage and the turbocharger are both connected to the reaction chamber of the reforming hydrogen production device through pipelines. The reaction chamber of the reforming hydrogen production device is used to decompose the ammonia-containing gas from the ammonia storage and the turbocharger to obtain hydrogen-containing gas, and provide the hydrogen-containing gas to the premixer;

[0007] The exhaust gas outlet of the ammonia engine is connected to the heating outer chamber of the reforming hydrogen production device through a pipeline, and the heating outer chamber of the reforming hydrogen production device is used to provide reaction heat for the reaction inner chamber of the reforming hydrogen production device;

[0008] The heating outer chamber of the reforming hydrogen production device is connected to the preheating box through a pipeline. The preheating box is used to preheat the ammonia-containing gas input into the reaction inner chamber of the reforming hydrogen production device through the ammonia engine exhaust gas from the heating outer chamber.

[0009] According to some embodiments of the present invention, the reaction inner chamber of the reforming hydrogen production device includes a top cavity, a bottom cavity and a plurality of pipes, the tops of the plurality of pipes are connected to the top cavity, and the bottoms of the plurality of pipes are connected to the bottom cavity; the plurality of pipes are arranged in the heating outer chamber, and the direction of the pipes is perpendicular to the flow direction of the ammonia engine exhaust gas in the heating outer chamber.

[0010] According to some embodiments of the present invention, the ammonia fuel combustion system further includes a cooling and liquid removal device, which is arranged on a pipeline between the reaction cavity of the reforming hydrogen production device and the premixer, and is used to remove moisture from the hydrogen-containing gas from the reaction cavity.

[0011] According to some embodiments of the present invention, a metal coil is wound around the outside of the reaction chamber of the reforming hydrogen production device.

[0012] According to some embodiments of the present invention, the ammonia fuel combustion system further includes an electric heater, which is arranged on the air inlet pipeline of the reaction chamber of the reforming hydrogen production device, and is used to heat the ammonia-containing gas input into the reaction chamber of the reforming hydrogen production device.

[0013] According to some embodiments of the present invention, the ammonia fuel combustion system further includes an exhaust gas treatment device, wherein the cooling and deliquidation device and the preheating box are both connected to the exhaust gas treatment device through pipelines, and the exhaust gas treatment device is used to react the ammonia-water mixture remaining in the cooling and deliquidation device with the ammonia engine exhaust gas passing through the preheating box, and discharge the treated tail gas after the reaction.

[0014] According to some embodiments of the present invention, the ammonia storage is connected to the exhaust gas treatment device through a pipeline, and a pollutant concentration sensor is further provided on the exhaust port of the exhaust gas treatment device.

[0015] According to some embodiments of the present invention, the ammonia fuel combustion system further includes a controller, wherein the controller is configured to:

[0016] Obtain the operating power and operating time of the ammonia engine;

[0017] determining a current operating stage of the ammonia engine according to the operating power and the operating time;

[0018] determining corresponding ammonia engine fuel requirements and system operating modes according to the operating phase;

[0019] The corresponding system components are turned on according to the system operating mode, and the operating parameters of the system components are adjusted according to the fuel demand of the ammonia engine, wherein the system components include an ammonia engine, a reforming hydrogen production device, an ammonia storage, a turbocharger, a metal coil power supply device and an electric heater.

[0020] According to some embodiments of the present invention, the ammonia fuel combustion system further includes a controller, wherein the controller is configured to:

[0021] obtaining a pollutant concentration value through the pollutant concentration sensor;

[0022] When the pollutant concentration value is greater than the concentration threshold, the valve on the pipeline between the ammonia storage and the exhaust gas treatment device is controlled to open so as to introduce ammonia into the exhaust gas treatment device.

[0023] On the other hand, an embodiment of the present invention further provides a control method for an ammonia fuel combustion system, which is applied to the ammonia fuel combustion system of the above embodiment. The control method includes the following steps:

[0024] Obtain the operating power and operating time of the ammonia engine;

[0025] determining a current operating stage of the ammonia engine according to the operating power and the operating time;

[0026] determining corresponding ammonia engine fuel requirements and system operating modes according to the operating phase;

[0027] The corresponding system components are turned on according to the system operating mode, and the operating parameters of the system components are adjusted according to the fuel demand of the ammonia engine, wherein the system components include an ammonia engine, a reforming hydrogen production device, an ammonia storage, a turbocharger, a metal coil power supply device and an electric heater.

[0028] The above technical solution of the present invention has at least one of the following advantages or beneficial effects: the ammonia fuel combustion system includes an ammonia engine, a reforming hydrogen production device, a preheating box, an ammonia storage device, a premixer and a turbocharger, and the reforming hydrogen production device includes a reaction chamber and a heating outer chamber. The premixer mixes the gases from the ammonia storage device, the turbocharger and the reaction chamber of the reforming hydrogen production device. The reaction chamber of the reforming hydrogen production device decomposes the ammonia-containing gas from the ammonia storage device and the turbocharger to obtain hydrogen-containing gas, and provides the hydrogen-containing gas to the premixer. The exhaust gas outlet of the ammonia engine is connected to the heating outer chamber of the reforming hydrogen production device through a pipeline, and the heating outer chamber of the reforming hydrogen production device provides reaction heat for the reaction chamber of the reforming hydrogen production device. The heating outer chamber of the reforming hydrogen production device is connected to the preheating box through a pipeline. The preheating box is used to preheat the ammonia-containing gas input into the reaction inner chamber of the reforming hydrogen production device through the ammonia engine exhaust gas from the heating outer chamber. By utilizing the ammonia engine exhaust gas to provide reaction heat for the reforming hydrogen production device, and then utilizing the ammonia engine exhaust gas for a second time to preheat the ammonia-containing gas ready to enter the reaction inner chamber, the heat exchange efficiency of the hydrogen production reaction is improved, the hydrogen production amount is increased, and thus the engine operating performance is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a schematic diagram of an ammonia fuel combustion system provided by an embodiment of the present invention;

[0030] Figure 2 This is a schematic structural diagram of a reforming hydrogen production device provided in an embodiment of the present invention;

[0031] Figure 3 This is a partial cross-sectional view of a reforming hydrogen production device provided by an embodiment of the present invention and provided with metal coils;

[0032] Figure 4 This is a communication connection diagram of an ammonia fuel combustion system provided by an embodiment of the present invention;

[0033] Figure 5 This is a flow chart of a control method for an ammonia fuel combustion system provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0034] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar components or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0035] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention.

[0036] In the description of the present invention, if there is a description of first, second, etc., it is only for the purpose of distinguishing technical features, and cannot be understood as indicating or suggesting relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0037] Please refer to Figure 1 An embodiment of the present invention provides an ammonia fuel combustion system, including: an ammonia engine 101, a reforming hydrogen production device 102, a preheating box 103, an ammonia storage 104, a premixer 105 and a turbocharger 106, wherein the reforming hydrogen production device includes a reaction inner chamber and a heating outer chamber.

[0038] The ammonia reservoir, turbocharger, and reaction chamber of the reforming hydrogen production unit are all connected to a premixer via pipelines, and the premixer is connected to the feed port of the ammonia engine via pipelines. The ammonia reservoir is used to store ammonia fuel, the turbocharger is used to transport a certain amount of external air into the premixer for premixing with ammonia, and the premixer is used to mix the gases from the ammonia reservoir, turbocharger, and reaction chamber of the reforming hydrogen production unit. Furthermore, a first plasma generator 107 is also provided at the fuel outlet of the ammonia reservoir. The plasma generator can activate the ammonia gas flowing through it, thereby improving the combustion characteristics of ammonia. In this embodiment, the provision of a premixer enables the fuel and air to be directly injected into the cylinder without premixing in the intake duct of the ammonia engine, and then introduced into the engine for combustion.

[0039] The ammonia storage and turbocharger are both connected to the reaction chamber of the reforming hydrogen production device through pipelines. The reaction chamber of the reforming hydrogen production device is used to decompose the ammonia-containing gas from the ammonia storage and turbocharger to obtain hydrogen-containing gas, and provide the hydrogen-containing gas to the premixer. The exhaust gas outlet of the ammonia engine is connected to the heating outer chamber of the reforming hydrogen production device through a pipeline. The heating outer chamber of the reforming hydrogen production device is used to provide reaction heat for the reaction chamber of the reforming hydrogen production device. The heating outer chamber of the reforming hydrogen production device is connected to the preheating box through a pipeline. The preheating box is used to preheat the ammonia-containing gas input into the reaction chamber of the reforming hydrogen production device through the ammonia engine exhaust gas from the heating outer chamber. This embodiment uses the ammonia engine exhaust gas to provide reaction heat for the reforming hydrogen production device, and then uses the ammonia engine exhaust gas a second time to preheat the ammonia-containing gas to enter the reaction chamber, thereby improving the heat exchange efficiency of the hydrogen production reaction, increasing the hydrogen production amount, and thus improving the engine operating performance.

[0040] According to some embodiments of the present invention, please refer to Figure 2 The reaction chamber of the reforming hydrogen production device includes a top cavity 201, a bottom cavity 202 and a plurality of pipes 203. The tops of the plurality of pipes are connected to the top cavity, and the bottoms of the plurality of pipes are connected to the bottom cavity. The plurality of pipes are arranged in the heating outer cavity 204, and the direction of the pipes is perpendicular to the flow direction of the ammonia engine exhaust gas in the heating outer cavity. Specifically, in the reforming hydrogen production device, the engine exhaust gas with residual heat passes from the inside of the horizontal shell (such as Figure 2 (as shown by the orange arrow in the middle), the gas and catalyst in the tube bundle are heated and insulated, and the ammonia-carrying gas and air (i.e., ammonia-containing gas) pass through the vertical tube bundle inlet and then flow out from the outlet (as shown by the blue arrow), and the overall macroscopic flow direction of the two is reversed. There is space for gas diffusion and diversion at the top and bottom of the reaction cavity, and there is a baffle at the air inlet to allow the gas to enter the tube evenly. Catalysts that promote oxidation and decomposition hydrogen production reactions are accumulated inside the pipeline. There is a certain distance between the tube bundles to promote turbulent flow of hot exhaust gas and enhance heat exchange. The air inlet is connected to the shell by a flange and screws, and is sealed by a sealing sheet for easy installation and disassembly. The reforming hydrogen production device proposed in this embodiment has a compact structure, a small footprint, high space and material utilization, and does not require a baffle structure inside, so the initial cost is low. For the reformer, the compact structure can improve the overall hydrogen production efficiency. Compared with the shell-and-tube reformer with a baffle structure in the related art, the reforming hydrogen production device proposed in this embodiment has a lower flow resistance, so the heat exchange efficiency under unit back pressure is higher. At the same time, the front-to-back arrangement of multiple pipes makes the types of catalysts used more flexible. For example, a catalyst that promotes the decomposition of ammonia to produce hydrogen and a catalyst that promotes the oxidation and heat release of ammonia can be used at the same time to provide the required heat for the hydrogen production reaction, or a part of the pipe can be left as an empty pipe to be fully preheated so that it reaches a more suitable reaction temperature when it comes into initial contact with the catalyst.

[0041] According to some embodiments of the present invention, please refer to Figure 3 The outside of the reaction chamber of the reforming hydrogen production device is wound with a metal coil 301, which can also be understood as a metal coil wound outside the heating outer chamber. Specifically, a sleeve is set on the side of the heating outer chamber to accommodate the discharge coil. Figure 3 The brownish-yellow section represents the cross-section of the electric coils. The coils are wound in the same direction, ensuring the magnetic fields are aligned and prevent mutual cancellation. By controlling the voltage and current applied to the metal coils, the frequency and intensity of the magnetic field generated are controlled, regulating the reformer's hydrogen production efficiency and, consequently, its hydrogen output, to meet the engine's intake requirements under varying operating conditions.

[0042] According to some embodiments of the present invention, please continue to refer to Figure 1The ammonia fuel combustion system also includes a cooling and liquid removal device 108, which is arranged on the pipeline between the reaction cavity of the reforming hydrogen production device and the premixer. The cooling and liquid removal device is used to remove moisture from the hydrogen-containing gas from the reaction cavity. In the reaction cavity of the reforming hydrogen production device, a part of the pipeline first performs an oxidation reaction on the input ammonia-containing gas to generate nitrogen and water vapor, releases heat, and heats the mixed gas mainly composed of ammonia. Then it is passed into the rear part of the pipeline to carry out a decomposition hydrogen production reaction to obtain a hydrogen-containing gas containing hydrogen, ammonia, nitrogen, and water vapor. The reaction cavity of the reforming hydrogen production device outputs the hydrogen-containing gas, the moisture therein is removed by the cooling and liquid removal device, and then the hydrogen-containing gas is mixed with ammonia through the premixer.

[0043] Furthermore, a second plasma generator 109 is provided on the pipeline between the cooling and liquid removal device and the premixer. The hydrogen-containing gas outputted from the reaction cavity of the reforming hydrogen production device is subjected to the cooling and liquid removal device to remove the moisture therein, and then is activated by the second plasma generator before entering the premixer for mixing treatment. Both the ammonia and hydrogen-rich gas entering the premixer are activated to improve their combustion characteristics, thereby improving the engine efficiency.

[0044] According to some embodiments of the present invention, please continue to refer to Figure 1 The ammonia fuel combustion system also includes an electric heater 110, which is disposed on the air inlet pipe of the reforming hydrogen production unit's reaction chamber. The electric heater is used to heat the ammonia-containing gas entering the reforming hydrogen production unit's reaction chamber. In this embodiment, the addition of the electric heater to the ammonia fuel combustion system can increase the upper limit of the ammonia inlet temperature of the reforming hydrogen production unit, thereby improving the maximum hydrogen production rate.

[0045] According to some embodiments of the present invention, the ammonia fuel combustion system further includes an exhaust gas treatment device 111. The cooling and deliquification device and the preheating tank are both connected to the exhaust gas treatment device via pipelines. The exhaust gas treatment device is configured to react the ammonia-water mixture remaining in the cooling and deliquification device with the ammonia engine exhaust gas that has passed through the preheating tank, and then discharge the treated exhaust gas after the reaction. In this embodiment, the ammonia-water mixture separated by the cooling and deliquification device is passed into the exhaust gas treatment device, where it undergoes a selective catalytic reaction with the engine exhaust gas after secondary heat exchange. The exhaust gas treatment device then discharges the reacted exhaust gas.

[0046] According to some embodiments of the present invention, the ammonia storage is connected to the exhaust gas treatment device through a pipeline, and a pollutant concentration sensor 112 is also provided on the exhaust port of the exhaust gas treatment device. The pollutant concentration sensor can be used to detect NO in the exhaust gas. X If the concentration is too high, part of the activated ammonia flowing through the first plasma generator is introduced to eliminate the harmful NOx substances therein and generate substances such as nitrogen and water that are harmless to the environment, which are then discharged into the atmosphere.

[0047] According to some embodiments of the present invention, the ammonia fuel combustion system further includes a controller, see Figure 1 and Figure 4 A flow meter 02 is provided at the outlet of the ammonia storage device, a flow meter 01 is provided on the pipeline between the preheating box and the turbocharger, a flow meter 03 is provided on the pipeline between the ammonia storage device and the preheating box, and a flow meter 04 is provided on the pipeline between the ammonia storage device and the exhaust gas treatment device. Each flow meter, the electric valve on each pipeline and the pollutant concentration sensor are connected to the controller. In addition, the controller can also communicate with each system component in the ammonia fuel combustion system, and the controller can control the working status of the system components.

[0048] The controller can automatically control the ammonia fuel combustion system. The controller is specifically used for:

[0049] Obtain the operating power and operating time of the ammonia engine;

[0050] Determine the current operating stage of the ammonia engine based on the operating power and operating time;

[0051] Determine the corresponding ammonia engine fuel requirements and system operating mode according to the operating stage;

[0052] The corresponding system components are turned on according to the system operating mode, and the operating parameters of the system components are adjusted according to the fuel demand of the ammonia engine. The system components include an ammonia engine, a reforming hydrogen production device, an ammonia storage, a turbocharger, a metal coil power supply device and an electric heater.

[0053] Specifically, the working modes of each system are described as follows:

[0054] First system operating mode: During initial operation of the system, there is no high-temperature exhaust gas to heat the catalyst and ammonia. Pure ammonia combustion is adopted, and ammonia flows out of the ammonia storage tank and flows through the first plasma generator. The first plasma generator activates the ammonia flowing through to improve the combustion characteristics of ammonia. The turbocharger delivers a certain amount of external air into the premixer for premixing with ammonia, and then the mixed gas in the premixer is input into the ammonia engine for combustion.

[0055] Second system operating mode: When engine power is greater than the first and second preset values, this phase is a low-load operation phase, utilizing ammonia-hydrogen mixed combustion. In this mode, ammonia from the ammonia reservoir is activated by the first plasma generator and then introduced into a preheating tank along with a certain proportion of air from the turbocharger. In the preheating tank, the ammonia-air mixture undergoes a secondary heat exchange with the engine exhaust gas, which has undergone a primary heat exchange in the reforming hydrogen production unit, achieving a preheating effect. The ammonia-air mixture then flows into the reforming hydrogen production unit. In the reforming hydrogen production unit, ammonia is first oxidized in a portion of the pipeline to produce nitrogen and water vapor, releasing heat to heat the ammonia-based mixture. The heated ammonia-containing gas is then decomposed in a subsequent portion of the pipeline to produce hydrogen, resulting in a hydrogen-containing gas composed of hydrogen, ammonia, nitrogen, and water vapor. The reforming hydrogen production unit outputs hydrogen-containing gas, which passes through a cooling and dehydration unit to separate hydrogen, nitrogen, and ammonia. The cooling and dehydration unit removes the water. The hydrogen-rich gas then enters a second plasma generator for activation and then enters a premixer for premixing with ammonia and air. The gas output from the premixer is fed into an ammonia engine for combustion.

[0056] System 3 operating mode: When engine power is greater than the second preset value and less than the third preset value, ammonia-hydrogen mixed combustion is employed. This system operates in addition to the second system operating mode, activating the metal coil. In the reforming hydrogen production unit, this system couples the heat released by ammonia oxidation with the metal coil's enhanced catalyst activity and exhaust gas heat. This system utilizes oxidation heat and exhaust gas heat to provide reaction heat. When the metal coil is energized, electromagnetic induction increases catalyst activity, reduces reaction activation energy, and increases and controls hydrogen production.

[0057] In the fourth system operating mode, when engine power exceeds the third preset value, the engine operates at high speed, utilizing ammonia-hydrogen mixed combustion. This fourth system operating mode builds on the third system operating mode by activating the electric heater to a certain temperature, heating the ammonia and further increasing and controlling hydrogen production.

[0058] In some embodiments, a hydrogen concentration sensor 113 is further provided at the outlet of the reaction chamber of the reforming hydrogen production device. The hydrogen concentration sensor is connected to a controller. The controller monitors the hydrogen concentration in the hydrogen-containing gas output by the reforming hydrogen production device, thereby judging whether the hydrogen content input to the ammonia engine meets the engine operation standard, and then adjusts the hydrogen content output by the reforming hydrogen production device by adjusting the amount of current flowing into the metal coil and the power of the electric heater.

[0059] In some embodiments, please refer to Figure 4To meet engine operating requirements, the controller matches the engine operating conditions and transmits speed and temperature signals to the host computer to obtain speed n and temperature t. The host computer then transmits signal instructions back to the controller based on the operating conditions and engine parameters. The controller activates the driver module, which in turn controls each flow meter. Real-time sensor monitoring then monitors the hydrogen content entering the engine and the NOx content in the exhaust gas, ensuring that the flow of each working fluid matches the engine operation and that the exhaust gas meets environmental protection requirements. The controller's control logic for implementing various system operating modes is as follows:

[0060] When the engine speed starts running from n=0 (i.e., the initial operating power is zero) for 5 seconds, this stage is determined to be the startup stage, and pure ammonia startup is used, corresponding to the first system working mode. In the first system working mode, the host computer matches the amount of ammonia required by the engine and sends a signal to the controller. The controller drives the drive module to turn on the flow meter 02 and the turbocharger, controls the air flow entering the system, and controls the ammonia flow into the premixer through the electric valve of the pipeline between the ammonia reservoir and the premixer. It should be noted that since the flow meter 01 is not turned on, the air flow into the system is the flow into the premixer, and the plasma generator is started and regulated to activate the ammonia, matching the ammonia inlet flow, and then entering the engine for combustion. The engine transmits the relevant operating data to the host computer. If the operating state is stable for 5s, the startup stage is stable and the system startup is successful.

[0061] After the startup phase, when engine power is greater than the first preset value and less than the second preset value, this phase enters low-load operation, utilizing ammonia-hydrogen mixed combustion, corresponding to the second system operating mode. The host computer matches the required fuel ratio for the engine and sends a signal to the controller. The controller activates the driver module to activate and regulate flowmeter 03, while also regulating flowmeters 01 and 02, thereby adjusting the engine's ammonia-hydrogen fuel ratio. The driver module also activates and regulates the second plasma generator to match the ammonia inlet flow rate. Ammonia enters the reforming hydrogen production unit for reaction. A hydrogen concentration sensor monitors the hydrogen concentration generated by the reforming hydrogen production unit in real time. By adjusting the ammonia content entering the reforming hydrogen production unit, the hydrogen content at its output meets the engine operating standard. Finally, operating condition-related signals such as engine speed and torque, as well as the exhaust gas temperature signal, are transmitted to the controller, which then transmits them to the host computer to meet operating requirements.

[0062] When the engine power is greater than the second preset value and less than the third preset value, ammonia-hydrogen mixed combustion is used, corresponding to the third system operating mode. In the third system operating mode, the host computer matches the required fuel ratio for the engine and sends a signal to the controller. The controller drives the driver module to adjust flowmeter O3, while also adjusting flowmeters O1 and O2, thereby adjusting the engine's ammonia-hydrogen fuel ratio. The driver module sends a control signal to the electric coil to achieve a certain magnetic field strength. Simultaneously, the hydrogen concentration sensor monitors the hydrogen concentration generated by the reforming hydrogen production unit in real time. By adjusting the ammonia content input to the reforming hydrogen production unit and the current flowing through the metal coil, the hydrogen content output meets the engine operating standard. Finally, the controller transmits operating condition-related signals such as engine speed and torque, as well as the exhaust gas temperature signal, to the host computer to ensure that the operating conditions are met.

[0063] When the engine power is greater than the third preset value, this stage enters the high-speed operation stage, using ammonia-hydrogen mixed combustion and the fourth system operating mode. In the fourth system operating mode, the host computer matches the required fuel ratio of the engine and sends a signal to the controller. The controller drives the driver module to activate and adjust flowmeter O3, while also adjusting flowmeters O1 and O2. The controller drives the driver module to send control signals to the electric heater and the metal coil power supply, controlling the heating temperature of the electric heater and the magnetic field strength of the metal coil, thereby adjusting the corresponding engine ammonia-hydrogen fuel ratio. At the same time, the hydrogen concentration sensor monitors the hydrogen concentration generated by the reforming hydrogen production device in real time. By adjusting the ammonia content input to the reforming hydrogen production device, the amount of power supplied to the metal coil, and the power of the electric heater, the hydrogen content output by the reforming hydrogen production device is adjusted to meet the engine operating standard. The plasma generator is controlled to activate the ammonia and match the ammonia inlet flow rate. Finally, the engine transmits operating condition-related signals such as speed and torque, as well as the exhaust gas temperature signal, to the controller, which then transmits them to the host computer to ensure that the operating conditions are met.

[0064] According to some embodiments of the present invention, the ammonia fuel combustion system further includes a controller, wherein the controller is configured to:

[0065] Obtaining pollutant concentration values ​​through pollutant concentration sensors;

[0066] When the pollutant concentration value is greater than the concentration threshold, the valve on the pipeline between the ammonia storage tank and the exhaust gas treatment device is controlled to open to allow ammonia to flow into the exhaust gas treatment device.

[0067] Please continue to refer to Figure 4After the engine exhaust flows through the reforming hydrogen production unit, it enters the exhaust gas treatment unit for a selective catalytic reaction. Simultaneously, a pollutant concentration sensor monitors the exhaust gas in real time and transmits the component concentrations to the host computer. If the host computer determines that the NOx content exceeds the standard, it sends a command to the controller. The driver module controls the corresponding electric valve based on the command to pass a portion of the ammonia activated by the first ion generator into the exhaust gas treatment unit, thereby eliminating the harmful NOx.

[0068] According to some embodiments of the present application, the embodiments of the present application have the following beneficial effects:

[0069] (1) A multi-stage energy utilization and waste gas treatment system is used to utilize the waste heat from the engine exhaust. A coupling coil magnetic field enhances catalyst activity, an electric heater raises the initial reaction temperature of the reactant gas, and a plasma generator activates all reacting ammonia. In the reforming hydrogen production unit, the exothermic ammonia oxidation reaction and hydrogen production proceed simultaneously, resulting in a high and easily controllable hydrogen production rate and high energy utilization.

[0070] (2) The structural design of the reforming hydrogen production device. The vertical arrangement of the pipelines can make the space more compact. Different catalysts can be stacked between the sections of the pipeline according to the needs to meet the needs of efficient hydrogen production. The oxidation heat release of the hydrogen-carrying substance and the endothermic heat of hydrogen production are combined to provide heat for the endothermic reaction of hydrogen production. The end cover and the shell are connected by screws to facilitate disassembly and catalyst stacking, improve the arrangement and spacing of the pipelines, enhance the turbulence of the exhaust gas, and enhance the heat exchange between the two. In addition, when a certain intensity voltage and current are passed through the metal coil around the reforming hydrogen production device, a certain magnetic field will be generated, thereby increasing the activity of the catalyst and reducing the reaction activation energy of the hydrogen production reaction, thereby further improving the hydrogen production efficiency and further controlling the hydrogen production rate.

[0071] (3) A control strategy that matches the system's operating mode allows the controller to control the feed ratio of each material and the temperature of the electric heater, effectively improving energy utilization while meeting the complex operating conditions of the engine. In addition, the energy and harmful gas treatment components are controlled in separate zones and blocks, which are relatively independent and work in tandem.

[0072] (4) The cooling and deliquescence device only removes the water. Compared with the intercoolers of other related systems, the temperature of the gas flowing out of this cooling unit is relatively higher, which is more conducive to the combustion of fuel in the engine.

[0073] Please refer to Figure 5 The present invention also provides a method for controlling an ammonia fuel combustion system, which is applied to the ammonia fuel combustion system of the above embodiment. The method comprises the following steps:

[0074] Step S201, obtaining the operating power and operating time of the ammonia engine;

[0075] Step S202, determining the current operating stage of the ammonia engine according to the operating power and operating time;

[0076] Step S203, determining the corresponding ammonia engine fuel requirement and system operating mode according to the operating stage;

[0077] In step S204, corresponding system components are turned on according to the system operating mode, and operating parameters of the system components are adjusted according to the fuel demand of the ammonia engine. The system components include the ammonia engine, the reforming hydrogen production device, the ammonia storage, the turbocharger, the power supply device of the metal coil, and the electric heater.

[0078] It can be understood that the contents of the above system embodiments are applicable to the present method embodiments, the functions specifically implemented by the present method embodiments are the same as those of the above system embodiments, and the beneficial effects achieved are also the same as those achieved by the above system embodiments.

[0079] The embodiments of the present invention are described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Various changes can be made within the knowledge of ordinary technicians in the relevant technical field without departing from the scope of the present invention.

Claims

1. An ammonia fuel combustion system, characterized in that: include: An ammonia engine, a reforming hydrogen production device, a preheating tank, an ammonia storage device, a premixer and a turbocharger, wherein the reforming hydrogen production device includes a reaction inner chamber and a heating outer chamber; The ammonia storage, the turbocharger, and the reaction chamber of the reforming hydrogen production device are all connected to the premixer through pipelines, and the premixer is connected to the feed port of the ammonia engine through a pipeline. The premixer is used to mix the gases from the ammonia storage, the turbocharger, and the reaction chamber of the reforming hydrogen production device; The ammonia storage and the turbocharger are both connected to the reaction chamber of the reforming hydrogen production device through pipelines. The reaction chamber of the reforming hydrogen production device is used to decompose the ammonia-containing gas from the ammonia storage and the turbocharger to obtain hydrogen-containing gas, and provide the hydrogen-containing gas to the premixer; The exhaust gas outlet of the ammonia engine is connected to the heating outer chamber of the reforming hydrogen production device through a pipeline, and the heating outer chamber of the reforming hydrogen production device is used to provide reaction heat for the reaction inner chamber of the reforming hydrogen production device; The heating outer chamber of the reforming hydrogen production device is connected to the preheating box through a pipeline, and the preheating box is used to preheat the ammonia-containing gas input into the reaction inner chamber of the reforming hydrogen production device through the ammonia engine exhaust gas from the heating outer chamber; The reaction chamber of the reforming hydrogen production device includes a top cavity, a bottom cavity, and a plurality of pipes, the tops of the plurality of pipes are connected to the top cavity, and the bottoms of the plurality of pipes are connected to the bottom cavity; the plurality of pipes are arranged in the heating outer cavity, and the direction of the pipes is perpendicular to the flow direction of the ammonia engine exhaust gas in the heating outer cavity; the interior of the pipes is deposited with a catalyst that promotes oxidation and decomposition hydrogen production reactions; A metal coil is wound around the outside of the reaction cavity of the reforming hydrogen production device.

2. The ammonia fuel combustion system according to claim 1, characterized in that: The ammonia fuel combustion system also includes a cooling and liquid removal device, which is arranged on the pipeline between the reaction cavity of the reforming hydrogen production device and the premixer, and is used to remove moisture from the hydrogen-containing gas from the reaction cavity.

3. The ammonia fuel combustion system according to claim 2, characterized in that: The ammonia fuel combustion system further includes an electric heater, which is disposed on an air inlet pipeline of the reaction chamber of the reforming hydrogen production device and is used to heat the ammonia-containing gas input into the reaction chamber of the reforming hydrogen production device.

4. The ammonia fuel combustion system according to claim 3, characterized in that: The ammonia fuel combustion system also includes an exhaust gas treatment device. The cooling and liquid removal device and the preheating tank are both connected to the exhaust gas treatment device through pipelines. The exhaust gas treatment device is used to react the ammonia-water mixture remaining in the cooling and liquid removal device with the ammonia engine exhaust gas passing through the preheating tank, and discharge the treated tail gas after the reaction.

5. The ammonia fuel combustion system according to claim 4, characterized in that: The ammonia storage is connected to the exhaust gas treatment device through a pipeline, and a pollutant concentration sensor is also provided on the exhaust port of the exhaust gas treatment device.

6. The ammonia fuel combustion system according to claim 3, characterized in that: The ammonia fuel combustion system further includes a controller, which is configured to: Obtain the operating power and operating time of the ammonia engine; determining a current operating stage of the ammonia engine according to the operating power and the operating time; determining corresponding ammonia engine fuel requirements and system operating modes according to the operating phase; The corresponding system components are turned on according to the system operating mode, and the operating parameters of the system components are adjusted according to the fuel demand of the ammonia engine, wherein the system components include an ammonia engine, a reforming hydrogen production device, an ammonia storage, a turbocharger, a metal coil power supply device and an electric heater.

7. The ammonia fuel combustion system according to claim 5, characterized in that: The ammonia fuel combustion system further includes a controller, which is configured to: obtaining a pollutant concentration value through the pollutant concentration sensor; When the pollutant concentration value is greater than the concentration threshold, the valve on the pipeline between the ammonia storage and the exhaust gas treatment device is controlled to open so as to introduce ammonia into the exhaust gas treatment device.

8. A control method for an ammonia fuel combustion system, characterized in that: Applied to the ammonia fuel combustion system according to claim 3, the control method comprises the following steps: Obtain the operating power and operating time of the ammonia engine; determining a current operating stage of the ammonia engine according to the operating power and the operating time; determining corresponding ammonia engine fuel requirements and system operating modes according to the operating phase; The corresponding system components are turned on according to the system operating mode, and the operating parameters of the system components are adjusted according to the fuel demand of the ammonia engine, wherein the system components include an ammonia engine, a reforming hydrogen production device, an ammonia storage, a turbocharger, a metal coil power supply device and an electric heater.

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