Ammonia-hydrogen fusion engine system and its control method

Abstract

This application belongs to the field of clean energy technology, specifically relating to an ammonia-hydrogen fusion engine system and its control method. The ammonia-hydrogen fusion engine includes an engine, a liquid ammonia vaporization device, an ammonia reaction hydrogen production device, a hydrogen-nitrogen mixer, and an overheat protection device. The overheat protection device includes: a bypass branch connected in parallel with the ammonia reaction hydrogen production device, one end of which is connected to the upstream of a second pipeline, and the other end connected to the downstream of the second pipeline; a bypass valve located on the bypass branch; a first sensor located upstream of the second pipeline for sensing a first temperature of the exhaust gas, and a second sensor located on the ammonia reaction hydrogen production device for sensing a second temperature of the catalyst; and a controller for adjusting the opening of the bypass valve based on the relationship between the first temperature, the second temperature, and a target temperature threshold. This application can improve the conversion rate of ammonia to hydrogen and the utilization rate of exhaust gas heat, while also providing overheat protection for the ammonia reaction hydrogen production device.

Description

Technical Field

[0001] This application relates to the field of clean energy technology, and more specifically, to an ammonia-hydrogen fusion engine system and its control method. Background Technology

[0002] With industrial development and increasing emphasis on environmental protection, the use and research of various clean energy sources have gradually begun. Among them, hydrogen energy, as a highly efficient and environmentally friendly green energy source, is widely used. However, the storage, transportation, and supply chain costs of hydrogen energy have always been one of the obstacles to its development. Ammonia, as a bulk inorganic compound, is easy to transport and store after liquefaction. Moreover, ammonia is a carbon-free, hydrogen-rich energy carrier. Therefore, the ammonia-hydrogen fusion engine system, which produces hydrogen through ammonia decomposition as fuel, represents a technological solution with good economic benefits and sustainable development.

[0003] The ammonia-hydrogen reaction unit is a crucial component of the ammonia-hydrogen fusion engine system. Its internal operation is an endothermic expansion reaction, making it highly sensitive to temperature fluctuations. Under actual operating conditions, the ammonia-hydrogen reaction unit needs to be controlled within a specific temperature range. Temperatures below the target range result in low conversion efficiency, negatively impacting the overall combustion performance of the ammonia-hydrogen fusion engine system. Temperatures above the operating temperature cause a decrease in catalyst activity, leading to irreversible damage. Most existing ammonia-hydrogen reaction units utilize external electric heaters as a heat source, consuming significant amounts of electrical energy. Furthermore, the exhaust heat from the ammonia-hydrogen fusion engine system removes some energy, further reducing the system's efficiency. Summary of the Invention

[0004] The purpose of this application is to provide an ammonia-hydrogen fusion engine system and its control method, which can improve the conversion rate of ammonia to hydrogen and the utilization rate of exhaust gas heat, and provide overheat protection for the ammonia reaction hydrogen production device, ensuring that the ammonia reaction hydrogen production device operates within safe and effective boundary conditions.

[0005] In a first aspect, embodiments of this application provide an ammonia-hydrogen fusion engine system, including an engine, a liquid ammonia vaporization device, an ammonia reaction hydrogen production device, a hydrogen-nitrogen mixer, and an overheat protection device. The engine has an intake manifold and an exhaust manifold. The intake manifold is connected to the hydrogen-nitrogen mixer via a first pipe, and the exhaust manifold discharges exhaust gas via a second pipe. The second pipe passes through the ammonia reaction hydrogen production device, which is internally filled with a catalyst. The ammonia reaction hydrogen production device has an inlet end and an outlet end. The inlet end is connected to the liquid ammonia vaporization device via a third pipe. The liquid ammonia vaporization device is used to vaporize liquid ammonia into ammonia gas. The outlet end is connected to the hydrogen-nitrogen mixer via a fourth pipe. The gas mixer is connected; the overheat protection device includes: a bypass branch, which is connected in parallel with the ammonia reaction hydrogen production unit, one end of which is connected to the upstream of the second pipeline and the other end of which is connected to the downstream of the second pipeline; a bypass valve, which is installed on the bypass branch; a first sensor and a second sensor, the first sensor being installed upstream of the second pipeline for sensing the first temperature of the exhaust gas, and the second sensor being installed on the ammonia reaction hydrogen production unit for sensing the second temperature of the catalyst; and a controller, which is electrically connected to the first sensor, the second sensor and the bypass valve, for adjusting the opening degree of the bypass valve according to the relationship between the first temperature, the second temperature and the target temperature threshold.

[0006] In addition, the ammonia-hydrogen fusion engine according to this application may also have the following additional technical features:

[0007] In some embodiments of this application, the overheat protection device further includes a heat exchanger disposed on the bypass branch and upstream of the bypass valve, for exchanging heat with the exhaust gas entering the bypass branch.

[0008] In some embodiments of this application, the ammonia-hydrogen fusion engine system further includes a liquid supply device, which includes an inlet pipe and an outlet pipe that are connected to each other. The heat exchanger has an inlet and an outlet, with the inlet pipe connected to the inlet and the outlet pipe connected to the outlet.

[0009] In some embodiments of this application, the ammonia-hydrogen fusion engine system further includes an after-treatment device. The ammonia reaction hydrogen production device includes a hydrogen production chamber for containing ammonia and a catalyst. The inlet end and the outlet end are located in the hydrogen production chamber. A second pipeline passes through the hydrogen production chamber and is connected to the after-treatment device.

[0010] In some embodiments of this application, the ammonia reaction hydrogen production device is further equipped with a pressure sensor. Along the direction from the liquid ammonia vaporization device to the inlet end of the ammonia reaction hydrogen production device, a pressure regulating valve, a first buffer device, and an ammonia injection valve are sequentially installed on the third pipeline. The pressure regulating valve is used to regulate the pressure of the mixed gas containing hydrogen and nitrogen. Along the direction from the outlet end of the ammonia reaction hydrogen production device to the hydrogen-nitrogen mixer, a first filter, a second buffer device, and a hydrogen-nitrogen injection valve are sequentially installed on the fourth pipeline.

[0011] In some embodiments of this application, the engine's turbine is connected to the exhaust manifold, and the turbine is coaxially connected to the compressor to drive the compressor to increase the pressure of the air and hydrogen-nitrogen mixture; the hydrogen-nitrogen mixer is connected to the intake end of the compressor, and the exhaust end of the compressor is connected to the intake manifold through a first pipeline. The first pipeline is also equipped with an intercooler and a throttle valve. The intercooler is used to cool the air, hydrogen, nitrogen and ammonia mixture compressed by the compressor.

[0012] In some embodiments of this application, the hydrogen-nitrogen mixer is also connected to an air inlet pipe, and the air inlet pipe is also provided with a second filter for purifying the air.

[0013] In some embodiments of this application, the liquid ammonia vaporization device includes a liquid ammonia tank, a liquid ammonia pump, and a liquid ammonia vaporizer. The liquid ammonia tank is connected to the liquid ammonia vaporizer via the liquid ammonia pump. The engine's cooling water is connected to the liquid ammonia vaporizer via a fifth pipeline for heat exchange with the liquid ammonia in the liquid ammonia vaporizer. A control valve is provided on the fifth pipeline.

[0014] Secondly, embodiments of this application provide a control method for an ammonia-hydrogen fusion engine system, which is applied to the ammonia-hydrogen fusion engine system of various embodiments of this application. The control method includes: acquiring a first temperature of the exhaust gas sensed by a first sensor and a second temperature of the catalyst sensed by a second sensor; and adjusting the opening degree of a bypass valve according to the relationship between the first temperature, the second temperature and a target temperature threshold.

[0015] In some embodiments of this application, adjusting the opening degree of the bypass valve according to the relationship between the first temperature, the second temperature, and the target temperature threshold includes: controlling the bypass valve to close when the first temperature is lower than the first temperature threshold and the second temperature is lower than the second temperature threshold; and controlling the bypass valve to open when the first temperature is higher than the first temperature threshold and the second temperature is higher than the second temperature threshold, wherein the opening degree of the bypass valve changes linearly with the second temperature.

[0016] According to the ammonia-hydrogen fusion engine and its control method provided in the embodiments of this application, an overheat protection device is set in parallel with the ammonia reaction hydrogen production device. The overheat protection device includes a bypass branch, a bypass valve and a controller set on the bypass branch, as well as a first sensor for sensing the first temperature of the exhaust gas emitted by the engine and a second sensor for sensing the second temperature of the catalyst. The controller adjusts the opening degree of the bypass valve according to the relationship between the first temperature, the second temperature and the target temperature threshold. In this way, the conversion rate of ammonia to hydrogen and the heat utilization rate of exhaust gas can be improved by utilizing the exhaust gas emitted by the engine. At the same time, the overheat protection of the ammonia reaction hydrogen production device can be provided by controlling the opening degree of the bypass valve, ensuring that the ammonia reaction hydrogen production device operates within safe and effective boundary conditions.

[0017] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, specific embodiments of this application are given below. Attached Figure Description

[0018] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. Wherein:

[0019] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. Wherein:

[0020] Figure 1 This is a schematic diagram of the ammonia-hydrogen fusion engine system according to an embodiment of this application;

[0021] Figure 2 This is a schematic diagram of the overheat protection device according to an embodiment of this application;

[0022] Figure 3 This is a flowchart illustrating the control method of the ammonia-hydrogen fusion engine system according to an embodiment of this application.

[0023] The labels in the attached diagram are as follows:

[0024] 100. Ammonia-hydrogen fusion engine system;

[0025] 10. Overheat protection device; 20. Engine; 21. Intake manifold; 22. Exhaust manifold; 23. Turbine; 24. Control valve;

[0026] 30. Liquid ammonia vaporization device; 31. Liquid ammonia tank; 32. Liquid ammonia pump; 33. Liquid ammonia vaporizer; 34. Pressure regulating valve; 35. First buffer device; 36. Ammonia injection valve;

[0027] 40. Ammonia reaction hydrogen production unit; 41. Inlet end; 42. Outlet end;

[0028] 50. Hydrogen-nitrogen mixer; 51. First filter; 52. Second buffer device; 53. Hydrogen-nitrogen injection valve; 54. Compressor; 55. Intercooler; 56. Throttle valve;

[0029] 60. Air intake pipe; 61. Second filter; 70. After-treatment device;

[0030] 1. Bypass branch; 2. Heat exchanger; 2a. Inlet; 2b. Outlet; 3. Bypass valve; 4. First sensor; 5. Second sensor; 6. Controller;

[0031] a. First pipeline; b. Second pipeline; c. Third pipeline; d. Fourth pipeline; f. Fifth pipeline. Detailed Implementation

[0032] Exemplary embodiments of this application will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of this application are shown in the drawings, it should be understood that this application may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of this application and to fully convey the scope of this application to those skilled in the art.

[0033] It should be understood that the terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “described” as used herein may also include the plural forms. The terms “comprising,” “including,” “containing,” and “having” are inclusive and therefore indicate the presence of the stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not construed as requiring them to be performed in a particular order described or illustrated unless the order of performance is explicitly indicated. It should also be understood that additional or alternative steps may be used.

[0034] Although terms such as first, second, third, etc., may be used in this document to describe multiple elements, components, regions, layers, and / or segments, these elements, components, regions, layers, and / or segments should not be limited by these terms. These terms may be used only to distinguish one element, component, region, layer, or segment from another. Unless the context clearly indicates otherwise, terms such as "first," "second," and other numerical terms used herein do not imply order or sequence. Therefore, the first element, component, region, layer, or segment discussed below may be referred to as the second element, component, region, layer, or segment without departing from the teachings of the exemplary embodiments.

[0035] For ease of description, spatial relative terms may be used in the text to describe the relationship of one element or feature relative to another element or feature, as shown in the figure. These relative terms include, for example, "inside," "outside," "middle," "outer," "below," "below," "above," "over," etc. Such spatial relative terms are intended to include different orientations of the device in use or operation, other than those depicted in the figure. For example, if the device in the figure is flipped, an element described as "below other elements or features" or "below other elements or features" would subsequently be oriented as "above other elements or features" or "above other elements or features." Therefore, the example term "below" can include both upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or in other directions), and the spatial relative descriptors used in the text will be interpreted accordingly.

[0036] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0037] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0038] Figure 1 This is a schematic diagram of the ammonia-hydrogen fusion engine system according to an embodiment of this application. Figure 2 This is a schematic diagram of the overheat protection device according to an embodiment of this application.

[0039] See Figure 1 and Figure 2 This application provides an ammonia-hydrogen fusion engine system 100, including an engine 20, a liquid ammonia vaporization device 30, an ammonia reaction hydrogen production device 40, a hydrogen-nitrogen mixer 50, and an overheat protection device 10.

[0040] The engine 20 has an intake manifold 21 and an exhaust manifold 22. The intake manifold 21 is connected to the hydrogen-nitrogen mixer 50 through a first pipe a. The exhaust manifold 22 discharges exhaust gas through a second pipe b. The second pipe b passes through the ammonia reaction hydrogen production device 40. The ammonia reaction hydrogen production device 40 is filled with a catalyst. The ammonia reaction hydrogen production device 40 has an inlet end 41 and an outlet end 42. The inlet end 41 is connected to the liquid ammonia vaporization device 30 through a third pipe c. The liquid ammonia vaporization device 30 is used to vaporize liquid ammonia into ammonia gas. The outlet end 42 is connected to the hydrogen-nitrogen mixer 50 through a fourth pipe d.

[0041] The overheat protection device 10 includes a bypass branch 1, a bypass valve 3, a first sensor 4, a second sensor 5, and a controller 6.

[0042] Bypass branch 1 is connected in parallel with the ammonia reaction hydrogen production unit 40. One end of bypass branch 1 is connected to the upstream of the second pipeline b, and the other end is connected to the downstream of the second pipeline b. Bypass valve 3 is installed on bypass branch 1. First sensor 4 is installed upstream of the second pipeline b to sense the first temperature of the exhaust gas. Second sensor 5 is installed on the ammonia reaction hydrogen production unit 40 to sense the second temperature of the catalyst. Controller 6 is electrically connected to first sensor 4, second sensor 5, and bypass valve 3, and is used to adjust the opening degree of bypass valve 3 according to the relationship between the first temperature, the second temperature, and the target temperature threshold.

[0043] In this embodiment, the liquid ammonia vaporization device 30 is used to vaporize liquid ammonia into ammonia gas. The ammonia gas is supplied to the inlet 41 of the ammonia reaction hydrogen production device 40 through the third pipeline c. The ammonia reaction hydrogen production device 40 is filled with a catalyst, such as a ruthenium-based catalyst. Under the action of the catalyst, the ammonia gas can be decomposed more quickly and completely to generate hydrogen and nitrogen. An endothermic expansion reaction occurs inside the ammonia reaction hydrogen production device 40, which makes it highly sensitive to temperature. For example, when the catalyst temperature reaches, for example, 550°C, the ammonia hydrogen production efficiency can reach over 99%. Under actual operating conditions, the ammonia reaction hydrogen production device 40 needs to be controlled within a certain temperature range. When the temperature is lower than the target temperature, the conversion efficiency of ammonia hydrogen production is low, which will affect the overall combustion performance of the ammonia-hydrogen fusion engine system 100; when the temperature is higher than the operating temperature, the catalyst activity inside the ammonia reaction hydrogen production device 40 will decrease, causing irreversible damage.

[0044] Therefore, this embodiment fully utilizes the heat from the exhaust gas emitted from the exhaust manifold 22 of the engine 20 to heat the ammonia reaction hydrogen production device 40. Even during a cold start of the engine 20, the catalyst within the ammonia reaction hydrogen production device 40 can reach the required temperature. Specifically, the exhaust manifold 22 of the engine 20 emits exhaust gas through a second pipe b, which runs through the ammonia reaction hydrogen production device 40. The heat from the exhaust gas in the second pipe b heats the catalyst within the ammonia reaction hydrogen production device 40, allowing ammonia to decompose more quickly into hydrogen and nitrogen, improving the ammonia decomposition efficiency and the hydrogen content in the mixed gas, thereby increasing the ammonia-to-hydrogen conversion rate and the utilization rate of exhaust gas heat. Compared to related technologies that use additional heat sources such as electric heaters to heat the ammonia reaction hydrogen production device 40, this embodiment reduces power consumption and manufacturing costs.

[0045] Since the exhaust gas temperature emitted from the exhaust manifold 22 of engine 20 is as high as 500°C or more, the operating temperature of the ammonia decomposition catalyst, which operates below 500°C, needs to be carefully controlled. To prevent the ammonia reaction hydrogen production device 40 from being damaged due to excessive temperature, this embodiment of the application also provides an overheat protection device 10, which includes a bypass branch 1, a bypass valve 3, a first sensor 4, a second sensor 5, and a controller 6. The bypass branch 1 is connected in parallel with the ammonia reaction hydrogen production device 40. One end of the bypass branch 1 is connected to the upstream of the second pipeline b, and the other end is connected to the downstream of the second pipeline b, so that the bypass branch 1 can divert a portion of the exhaust gas emitted by engine 20, preventing all the exhaust gas from being emitted into the ammonia reaction hydrogen production device 40, which would cause it to overheat and be damaged. The bypass valve 3 is installed on the bypass branch 1. Meanwhile, a first sensor 4 is installed upstream of the second pipeline b to sense the first temperature of the exhaust gas, and a second sensor 5 is installed on the ammonia reaction hydrogen production unit 40 to sense the second temperature of the catalyst. The second temperature can be controlled within a certain range, such as 290℃~300℃. The controller 6 controls the opening of the bypass valve 3 by monitoring the first temperature of the exhaust gas from the engine 20 and the second temperature of the catalyst in the ammonia reaction hydrogen production unit 40 in real time, thereby adjusting the proportion of exhaust gas entering the ammonia reaction hydrogen production unit 40, achieving precise temperature control, and with simplified control logic and fast control response time.

[0046] Specifically, such as Figure 2As indicated by the middle arrow, when the first temperature T1 of the exhaust gas is lower than the first temperature threshold (e.g., 700°C) and the second temperature T2 of the catalyst is lower than the second temperature threshold (e.g., 600°C), the bypass valve 3 remains closed. All exhaust gas emitted by the engine 20 is discharged downstream of the second pipeline b through the ammonia reaction hydrogen production unit 40. At this time, the exhaust gas acts as a heat source to heat the ammonia reaction hydrogen production unit 40, fully utilizing the exhaust gas energy of the engine 20 to heat the ammonia reaction hydrogen production unit 40 and ensure that the ammonia reaction hydrogen production unit 40 operates within a high-efficiency conversion range. When the first temperature T1 of the exhaust gas is higher than the first temperature threshold and the second temperature T2 of the catalyst is higher than the second temperature threshold, the controller 6 starts working, controlling the bypass valve 3 to open. The opening degree of the bypass valve 3 changes linearly with the second temperature T2. That is, within a certain range, the higher the second temperature T2, the larger the opening degree of the bypass valve 3. When the second temperature T2 of the catalyst reaches the protection temperature threshold (e.g., 650°C), the bypass valve 3 is fully open. The opening degree of bypass valve 3 controls the discharge of different proportions of exhaust gas through bypass branch 1 to the downstream of ammonia reaction hydrogen production unit 40. At this time, the exhaust gas energy of engine 20 can be fully utilized to improve the conversion efficiency of ammonia reaction hydrogen production unit 40. At the same time, overheat protection of ammonia reaction hydrogen production unit 40 is taken into consideration to prevent damage to ammonia reaction hydrogen production unit 40 due to excessive temperature, and to ensure that ammonia reaction hydrogen production unit 40 operates within safe and effective boundary conditions.

[0047] It is understandable that the first and second temperature thresholds can also be other temperature values, depending on the specific application scenario, which will not be elaborated further.

[0048] According to the ammonia-hydrogen fusion engine system 100 provided in the embodiments of this application, an overheat protection device 10 is set in parallel with the ammonia reaction hydrogen production device 40. The overheat protection device 10 includes a bypass branch 1, a bypass valve 3 and a controller 6 set on the bypass branch 1, as well as a first sensor 4 for sensing the first temperature of the exhaust gas emitted by the engine 20 and a second sensor 5 for sensing the second temperature of the catalyst. The controller 6 adjusts the opening degree of the bypass valve 3 according to the relationship between the first temperature, the second temperature and the target temperature threshold. In this way, the conversion rate of ammonia to hydrogen and the exhaust gas heat utilization rate can be improved by utilizing the exhaust gas emitted by the engine 20. At the same time, the overheat protection of the ammonia reaction hydrogen production device 40 can be provided by controlling the opening degree of the bypass valve 3, ensuring that the ammonia reaction hydrogen production device operates within safe and effective boundary conditions.

[0049] In some embodiments, the overheat protection device 10 further includes a heat exchanger 2, which is disposed on the bypass branch 1 and located upstream of the bypass valve 3, for exchanging heat with the exhaust gas entering the bypass branch 1.

[0050] like Figure 2As shown, heat exchanger 2 is installed on bypass branch 1 and located upstream of bypass valve 3. It is used to exchange heat with the exhaust gas entering bypass branch 1 to cool down the high-temperature exhaust gas. The cooled exhaust gas can protect bypass valve 3 from damage due to excessive temperature, thus improving the reliability of overheat protection device 10. Heat exchanger 2 can be an air heat exchanger or a coolant heat exchanger.

[0051] In some embodiments, the ammonia-hydrogen fusion engine system 100 further includes a liquid supply device, which includes an inlet pipe and an outlet pipe that are connected to each other. The heat exchanger 2 has an inlet port 2a and an outlet port 2b, with the inlet pipe connected to the inlet port 2a and the outlet pipe connected to the outlet port 2b.

[0052] like Figure 2 As shown, heat exchanger 2 is a coolant heat exchange device, which has an inlet 2a and an outlet 2b. The coolant supply device includes an inlet pipe and an outlet pipe that are connected to each other. The inlet pipe is connected to the inlet 2a, and the outlet pipe is connected to the outlet 2b. Heat exchanger 2 exchanges heat with the exhaust gas entering the bypass branch 1 through coolant. The coolant can be water, oil, etc., to cool down the high-temperature exhaust gas.

[0053] In some embodiments, the ammonia-hydrogen fusion engine system 100 further includes an aftertreatment device 70, and the ammonia reaction hydrogen production device 40 includes a hydrogen production chamber for containing ammonia and a catalyst, with an inlet end 41 and an outlet end 42 disposed in the hydrogen production chamber, and a second pipeline b passing through the hydrogen production chamber and communicating with the aftertreatment device 70.

[0054] like Figure 1 As shown, in the catalytic decomposition reaction process of the ammonia reaction hydrogen production device 40, in order to fully utilize the heat energy of the combustion exhaust gas of the engine 20 and reduce the environmental impact of nitrogen oxides and unburned ammonia products in the exhaust gas of the engine 20, this application connects the exhaust manifold 22 of the engine 20 through a second pipe b through the hydrogen production chamber and then to the aftertreatment device 70. The heat of the exhaust gas is transferred to the hydrogen production chamber through the second pipe b, increasing the temperature of the catalyst in the hydrogen production chamber and improving the ammonia-to-hydrogen conversion rate. The aftertreatment device 7 can treat the nitrogen oxides and unburned ammonia products in the exhaust of the engine 20, so that the exhaust gas of the engine 20 meets the emission standards.

[0055] In some embodiments, the ammonia reaction hydrogen production device 40 is also equipped with a pressure sensor. Along the direction from the liquid ammonia vaporization device 30 to the inlet end 41 of the ammonia reaction hydrogen production device 40, a pressure regulating valve 34, a first buffer device 35 and an ammonia injection valve 36 are sequentially arranged on the third pipeline. The pressure regulating valve 34 is used to regulate the pressure of the mixed gas containing hydrogen and nitrogen. Along the direction from the outlet end 42 of the ammonia reaction hydrogen production device 40 to the hydrogen-nitrogen mixer 50, a first filter 51, a second buffer device 52 and a hydrogen-nitrogen injection valve 53 are sequentially arranged on the fourth pipeline d.

[0056] like Figure 1 As shown, the ammonia reaction hydrogen production unit 40 is also equipped with a pressure sensor (not shown in the figure). Along the ammonia flow direction in the third pipeline c, a pressure regulating valve 34, a first buffer device 35, and an ammonia injection valve 36 are sequentially installed on the third pipeline c. The pressure regulating valve 34 is used to control the pressure of the gas mixture containing hydrogen and nitrogen, for example, the pressure is less than 50 kPa. After being buffered by the first buffer device 35, the vaporized ammonia is injected into the ammonia reaction hydrogen production unit 40 through the ammonia injection valve 36. The ammonia injection valve 36 is used to control the amount of ammonia injected into the ammonia reaction hydrogen production unit 40.

[0057] A pressure sensor is used to monitor the pressure inside the ammonia reaction hydrogen production unit 40 during the ammonia decomposition process. The pressure of the vaporized ammonia is controlled via a pressure regulating valve 34, which can maintain the vaporized ammonia pressure within a certain range, such as 3 Bar to 5 Bar. A second sensor 5 and the pressure sensor monitor the ammonia reaction hydrogen production unit 40. Based on the temperature and pressure detected by the second sensor 5 and the pressure sensor, the internal temperature and pressure of the ammonia reaction hydrogen production unit 40 are adjusted accordingly, thereby controlling the conversion efficiency of the ammonia reaction hydrogen production unit 40. The pressure and control temperature ranges vary depending on the type of catalyst. For example, for a certain catalyst, its conversion efficiency can reach 20% at low pressure (1 bar (gauge pressure)) and temperature of 300°C. To control the proportion of hydrogen in the mixed gas, the conversion efficiency of the ammonia reaction hydrogen production unit 40 can be optionally controlled within the range of 10% to 20%. The pressure of the mixed gas containing hydrogen, nitrogen and ammonia discharged from the ammonia reaction hydrogen production unit 40 is controlled by controlling the inlet pressure of the catalyst. The pressure of the mixed gas containing hydrogen, nitrogen and ammonia discharged from the ammonia reaction hydrogen production unit 40 is less than a certain pressure, such as 50 kPa.

[0058] Furthermore, along the flow direction of hydrogen and nitrogen in the fourth pipeline d, a first filter 51, a second buffer device 52, and a hydrogen-nitrogen injection valve 53 are sequentially installed on the fourth pipeline d. The ammonia reaction hydrogen production device 40 is used to convert the input ammonia into a mixed gas containing hydrogen and nitrogen. The first filter 51 is used to filter impurities in the mixed gas. After the buffering effect of the second buffer device 52, the converted mixed gas containing hydrogen and nitrogen is injected into the hydrogen-nitrogen mixer 50 through the hydrogen-nitrogen injection valve 53.

[0059] In some embodiments, the hydrogen-nitrogen mixer 50 is also connected to an air inlet pipe 60, and the air inlet pipe 60 is also provided with a second filter 61 for purifying the air.

[0060] like Figure 1As shown, the hydrogen-nitrogen injection valve 53 is used to inject a mixture of hydrogen-nitrogen gas and a trace amount of undecomposed ammonia gas into the hydrogen-nitrogen mixer 50. The hydrogen-nitrogen mixer 50 is also connected to an air inlet pipe 60, and a second filter 61 is also provided on the air inlet pipe 60. The second filter 61 is used to purify the air, and the filtered air is input into the hydrogen-nitrogen mixer 50.

[0061] In some embodiments, the turbine 23 of the engine 20 is connected to the exhaust manifold 22, and the turbine 23 is coaxially connected to the compressor 54; the hydrogen-nitrogen mixer 50 is connected to the intake end of the compressor 54, and the outlet end of the compressor 54 is connected to the intake manifold 21 through the first pipe a. The first pipe a is also provided with an intercooler 55 and a throttle valve 56. The intercooler 55 is used to cool the air, hydrogen, nitrogen and ammonia mixture compressed by the compressor 54.

[0062] like Figure 1 As shown, in order to better utilize the high-temperature exhaust gas energy of the engine 20, in this embodiment, the exhaust manifold 22 of the engine 20 is connected to the turbine 23, the turbine 23 is coaxially connected to the compressor 54, and the hydrogen-nitrogen mixer 50 is connected to the compressor 54. The turbine 23 can drive the compressor 54 to rotate, thereby increasing the pressure of the air and hydrogen-nitrogen mixture. After the compressor 54 draws the pressurized air and the mixture of hydrogen, nitrogen, and ammonia into the intake manifold 21, a combustible mixture of hydrogen, nitrogen, ammonia, and air can be formed in the intake manifold 21 of the engine 20, wherein hydrogen accounts for 10% to 20% of the mixture. In addition, an intercooler 55 is provided between the intake manifold 21 and the compressor 23, and a throttle valve 56 is provided between the intercooler 55 and the intake manifold 21. The intercooler 55 is used to cool the air, hydrogen, and nitrogen mixture compressed by the compressor 54. The cooled air-fuel mixture enters the cylinder of engine 20. A spark plug near the top dead center of the compression stroke ignites the mixture, converting the chemical energy of fuel combustion into mechanical energy to power engine 20. Engine 20 includes essential engine components such as camshafts, intake and exhaust valves, crankshafts, and connecting rods. The exhaust gases from the combustion process are discharged through exhaust manifold 22 on engine 20 and then enter aftertreatment device 70.

[0063] In some embodiments, the liquid ammonia vaporization device 30 includes a liquid ammonia tank 31, a liquid ammonia pump 32, and a liquid ammonia vaporizer 33. The liquid ammonia tank 31 is connected to the liquid ammonia vaporizer 33 via the liquid ammonia pump 32. The cooling water of the engine 20 is connected to the liquid ammonia vaporizer 33 via a fifth pipeline f for heat exchange with the liquid ammonia in the liquid ammonia vaporizer 33. A control valve 24 is provided on the fifth pipeline f.

[0064] like Figure 1As shown, the liquid ammonia tank 31 is connected to the liquid ammonia vaporizer 33 via the liquid ammonia pump 32 to convert liquid ammonia into gaseous ammonia. When the engine 20 is running stably, the temperature of the cooling water discharged from the engine 20 can reach over 90°C. To further utilize the cooling water of the engine 20 and improve the energy recycling rate of the system, as an optional embodiment of this application, the cooling water of the engine 20 is connected to the liquid ammonia vaporizer 33 via a fifth pipe f for heat exchange with the liquid ammonia in the liquid ammonia vaporizer 33. The cooling water of the engine 20 flows through the liquid ammonia vaporizer 33, vaporizing the liquid ammonia. A control valve 24 is provided between the engine 20 and the liquid ammonia vaporizer 33, which can be opened or closed as needed.

[0065] Figure 3 This is a flowchart illustrating the control method of the ammonia-hydrogen fusion engine system according to an embodiment of this application.

[0066] See Figure 3 This application also provides a control method for an ammonia-hydrogen fusion engine system, applied to the ammonia-hydrogen fusion engine system 100 as described above. The control method includes:

[0067] Step S1: Obtain the first temperature of the exhaust gas sensed by the first sensor 4 and the second temperature of the catalyst sensed by the second sensor 5;

[0068] Step S2: Adjust the opening of bypass valve 3 according to the relationship between the first temperature, the second temperature and the target temperature threshold.

[0069] Combination Figure 1 and Figure 2 Since the exhaust gas temperature emitted from the exhaust manifold 22 of engine 20 is as high as 500°C or more, the operating temperature of the ammonia decomposition catalyst, which operates below 500°C, needs to be carefully controlled. To prevent the ammonia reaction hydrogen production unit 40 from being damaged due to overheating, the ammonia-hydrogen fusion engine system 100 is also equipped with an overheat protection device 10. The overheat protection device 10 includes a bypass branch 1, a bypass valve 3, a first sensor 4, a second sensor 5, and a controller 6. The bypass branch 1 is connected in parallel with the ammonia reaction hydrogen production unit 40. One end of the bypass branch 1 is connected to the upstream of the second pipeline b, and the other end is connected to the downstream of the second pipeline b. This allows the bypass branch 1 to divert a portion of the exhaust gas emitted by engine 20, preventing all the exhaust gas from being emitted into the ammonia reaction hydrogen production unit 40, which could lead to overheating and damage. The bypass valve 3 is installed on the bypass branch 1. Meanwhile, a first sensor 4 is installed upstream of the second pipeline b to sense the first temperature of the exhaust gas, and a second sensor 5 is installed on the ammonia reaction hydrogen production device 40 to sense the second temperature of the catalyst. The second temperature can be controlled within a certain range, such as 290℃~300℃.

[0070] Therefore, the control method of the ammonia-hydrogen fusion engine system is to control the opening of the bypass valve 3 by real-time monitoring of the first temperature of the exhaust gas of the engine 20 and the second temperature of the catalyst in the ammonia reaction hydrogen production device 40, thereby adjusting the proportion of exhaust gas entering the ammonia reaction hydrogen production device 40, achieving precise temperature control, and the control logic is simplified and the control response time is fast.

[0071] In some embodiments, step S2, adjusting the opening degree of the bypass valve 3 according to the relationship between the first temperature, the second temperature, and the target temperature threshold includes:

[0072] Step S21: Based on the fact that the first temperature T1 is lower than the first temperature threshold and the second temperature T2 is lower than the second temperature threshold, control the bypass valve 3 to close;

[0073] Step S22: Based on the fact that the first temperature T1 is higher than the first temperature threshold and the second temperature T2 is higher than the second temperature threshold, control the bypass valve 3 to open, and the opening degree of the bypass valve 3 changes linearly with the second temperature T2.

[0074] In this embodiment, the target temperature threshold includes a first temperature threshold and a second temperature threshold. The first temperature threshold can be, for example, 700℃, and the second temperature threshold can be, for example, 600℃. The first and second temperature thresholds can also be other temperature values, depending on the specific application scenario. When the first temperature T1 of the exhaust gas is lower than the first temperature threshold, and the second temperature T2 of the catalyst is lower than the second temperature threshold, the bypass valve 3 remains closed, and all the exhaust gas emitted by the engine 20 is discharged downstream of the second pipeline b through the ammonia reaction hydrogen production device 40. At this time, the exhaust gas acts as a heat source to heat the ammonia reaction hydrogen production device 40, fully utilizing the exhaust gas energy of the engine 20 to heat the ammonia reaction hydrogen production device 40, ensuring that the ammonia reaction hydrogen production device 40 operates within a high-efficiency conversion range. When the first temperature T1 of the exhaust gas is higher than the first temperature threshold, and the second temperature T2 of the catalyst is higher than the second temperature threshold, the controller 6 starts working, controlling the bypass valve 3 to open, and the opening degree of the bypass valve 3 changes linearly with the second temperature T2. That is, within a certain range, the higher the second temperature T2, the larger the opening degree of the bypass valve 3. When the catalyst's second temperature T2 reaches the protection temperature threshold, which can be, for example, 650°C, the bypass valve 3 is fully open. The opening degree of the bypass valve 3 controls the proportion of exhaust gas discharged through the bypass branch 1 to the downstream of the ammonia reaction hydrogen production unit 40. Thus, the conversion rate of ammonia to hydrogen and the utilization rate of exhaust gas heat can be improved by utilizing the exhaust gas emitted by the engine 20. Furthermore, by controlling the opening degree of the bypass valve 3, overheat protection can be provided for the ammonia reaction hydrogen production unit 40, ensuring that the ammonia reaction hydrogen production unit operates within safe and effective boundary conditions.

[0075] According to the control method of the ammonia-hydrogen fusion engine provided in the embodiments of this application, an overheat protection device 10 is set in parallel with the ammonia reaction hydrogen production device 40. The overheat protection device 10 includes a bypass branch 1, a heat exchanger 2 set on the bypass branch 1, a bypass valve 3 and a controller 6 located downstream of the heat exchanger 2, a first sensor 4 for sensing the first temperature of the exhaust gas emitted by the engine 20 and a second sensor 5 for sensing the second temperature of the catalyst. The controller 6 adjusts the opening degree of the bypass valve 3 according to the relationship between the first temperature, the second temperature and the target temperature threshold. In this way, the conversion rate of ammonia to hydrogen and the heat utilization rate of exhaust gas can be improved by utilizing the exhaust gas emitted by the engine 20. At the same time, the overheat protection of the ammonia reaction hydrogen production device 40 can be provided by controlling the opening degree of the bypass valve 3, ensuring that the ammonia reaction hydrogen production device operates within safe and effective boundary conditions.

[0076] The above description is merely a preferred embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An ammonia-hydrogen fusion engine system, characterized in that, The device includes an engine, a liquid ammonia vaporization unit, an ammonia reaction hydrogen production unit, a hydrogen-nitrogen mixer, and an overheat protection device. The engine has an intake manifold and an exhaust manifold. The intake manifold is connected to the hydrogen-nitrogen mixer via a first pipe. The exhaust manifold discharges exhaust gas via a second pipe, which passes through the ammonia reaction hydrogen production unit. The ammonia reaction hydrogen production unit is filled with a catalyst and has an inlet and an outlet. The inlet is connected to the liquid ammonia vaporization unit via a third pipe. The liquid ammonia vaporization unit is used to vaporize liquid ammonia into ammonia gas. The outlet is connected to the hydrogen-nitrogen mixer via a fourth pipe. The overheat protection device includes: A bypass branch is provided in parallel with the ammonia reaction hydrogen production unit. One end of the bypass branch is connected to the upstream of the second pipeline, and the other end is connected to the downstream of the second pipeline. A bypass valve is provided on the bypass branch; A first sensor and a second sensor, the first sensor being located upstream of the second pipeline for sensing a first temperature of the exhaust gas, and the second sensor being located on the ammonia reaction hydrogen production unit for sensing a second temperature of the catalyst; and The controller is electrically connected to the first sensor, the second sensor, and the bypass valve, and is used to adjust the opening degree of the bypass valve according to the relationship between the first temperature, the second temperature, and the target temperature threshold. The overheat protection device also includes a heat exchanger, which is disposed on the bypass branch and located upstream of the bypass valve, for exchanging heat with the exhaust gas entering the bypass branch.

2. The ammonia-hydrogen fusion engine system according to claim 1, characterized in that, The ammonia-hydrogen fusion engine system also includes a liquid supply device, which includes an inlet pipe and an outlet pipe that are connected to each other. The heat exchanger has an inlet and an outlet, with the inlet pipe connected to the inlet and the outlet pipe connected to the outlet.

3. The ammonia-hydrogen fusion engine system according to claim 1, characterized in that, The ammonia-hydrogen fusion engine system also includes an after-treatment device. The ammonia reaction hydrogen production device includes a hydrogen production chamber for containing ammonia and a catalyst. The inlet end and the outlet end are located in the hydrogen production chamber. The second pipeline passes through the hydrogen production chamber and is connected to the after-treatment device.

4. The ammonia-hydrogen fusion engine system according to claim 1, characterized in that, The ammonia reaction hydrogen production device is also equipped with a pressure sensor. Along the direction from the liquid ammonia vaporization device to the inlet end of the ammonia reaction hydrogen production device, a pressure regulating valve, a first buffer device, and an ammonia injection valve are sequentially installed on the third pipeline. The pressure regulating valve is used to regulate the pressure of the mixed gas containing hydrogen and nitrogen. Along the direction from the outlet end of the ammonia reaction hydrogen production device to the hydrogen-nitrogen mixer, a first filter, a second buffer device, and a hydrogen-nitrogen injection valve are sequentially installed on the fourth pipeline.

5. The ammonia-hydrogen fusion engine system according to claim 1, characterized in that, The hydrogen-nitrogen mixer is also connected to an air intake pipe, which is equipped with a second filter for purifying the air.

6. The ammonia-hydrogen fusion engine system according to claim 5, characterized in that, The turbine of the engine is connected to the exhaust manifold, and the turbine is coaxially connected to the compressor; the hydrogen-nitrogen mixer is connected to the intake end of the compressor, and the outlet end of the compressor is connected to the intake manifold through the first pipeline. The first pipeline is also equipped with an intercooler and a throttle valve. The intercooler is used to cool the air, hydrogen, nitrogen and ammonia mixture compressed by the compressor.

7. The ammonia-hydrogen fusion engine system according to claim 1, characterized in that, The liquid ammonia vaporization device includes a liquid ammonia tank, a liquid ammonia pump, and a liquid ammonia vaporizer. The liquid ammonia tank is connected to the liquid ammonia vaporizer via the liquid ammonia pump. The engine's cooling water is connected to the liquid ammonia vaporizer via a fifth pipeline for heat exchange with the liquid ammonia in the liquid ammonia vaporizer. A control valve is installed on the fifth pipeline.

8. A control method for an ammonia-hydrogen fusion engine system, applied to the ammonia-hydrogen fusion engine system as described in any one of claims 1 to 7, characterized in that, The control method includes: The first temperature of the exhaust gas sensed by the first sensor and the second temperature of the catalyst sensed by the second sensor are obtained. Adjust the opening degree of the bypass valve according to the relationship between the first temperature, the second temperature and the target temperature threshold.

9. The control method according to claim 8, characterized in that, The adjustment of the bypass valve opening based on the relationship between the first temperature, the second temperature, and the target temperature threshold includes: The bypass valve is controlled to close based on the first temperature being lower than a first temperature threshold and the second temperature being lower than a second temperature threshold. Based on the condition that the first temperature is higher than the first temperature threshold and the second temperature is higher than the second temperature threshold, the bypass valve is controlled to open, and the opening degree of the bypass valve changes linearly with the second temperature.

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