Ammonia fuel pretreatment device for ammonia fuel engine and pretreatment method thereof

Abstract

The application provides an ammonia fuel pretreatment device for an ammonia fuel engine and a pretreatment method thereof, wherein the device comprises an ammonia fuel main valve, a mixing device and a water injection unit; the ammonia fuel main valve and the mixing device are sequentially installed on an ammonia fuel supply pipeline between an ammonia fuel supply device and an ammonia fuel consumption device in a flow direction of the ammonia fuel from front to back; the water injection unit is connected with the mixing device and is used for forming a mixture of ammonia fuel and water in the mixing device. The application can pretreat the ammonia fuel by mixing water with different proportions in the ammonia fuel according to different loads of the ammonia fuel engine, so as to reduce the generation amount of nitrogen oxides in the ammonia fuel engine emissions, thereby reducing the nitrogen oxide emission of the ammonia fuel engine to meet the emission index.

Description

Technical Field

[0001] This invention relates to the field of nitrogen oxide emission technology for ships, and more specifically, to an ammonia fuel pretreatment device and method for reducing nitrogen oxide emissions from ammonia fuel engines. Background Technology

[0002] Faced with increasingly stringent ship emission regulations, the shipping industry is actively seeking solutions to achieve carbon neutrality and peak carbon emissions. Many new fuels, such as methanol, ammonia, and LNG, have attracted widespread attention from designers, shipyards, ship owners, and charterers. However, carbon-based fuels like LNG and methanol still suffer from the drawback of only slightly reducing carbon emissions compared to MDO fuels, failing to significantly reduce carbon emissions. Ammonia fuel, because it does not produce carbon oxides upon combustion, has mature industrial production technology, and possesses the potential to reduce carbon dioxide emissions during ship operation, attracting widespread interest from ship owners.

[0003] However, the combustion of ammonia fuel still produces harmful emissions—nitrogen oxides (NOx). NOx is a collective term for nitric oxide (NO), nitrogen dioxide (NO2), dinitrogen trioxide (N2O3), and others. Currently, the main measures to reduce NOx formation include exhaust gas recirculation (EGR) systems and exhaust gas aftertreatment (SCR, etc.).

[0004] The traditional approach to reducing NOx emissions in ammonia fuel engines currently used is to add an additional SCR reactor for exhaust gas aftertreatment. This involves injecting urea into the exhaust gas and mixing it with the urea. The mixture then passes through the SCR reactor, where a reduction reaction occurs under the guidance of a catalyst. The nitrogen oxides in the exhaust gas are reduced to N2, and the reaction also produces CO2 and water, which are then released into the atmosphere. However, this method requires an additional system for urea storage, injection, cleaning, and soot blowing. Furthermore, CO2 is introduced into the exhaust gas after the reaction due to the urea acting as a reducing agent. Although the engine's exhaust gas treats nitrogen oxides, the presence of urea prevents it from achieving "zero carbon" emissions. Summary of the Invention

[0005] To address the aforementioned shortcomings in the prior art, this invention provides an ammonia fuel pretreatment device and method for ammonia fuel engines.

[0006] This invention is achieved through the following technical solutions.

[0007] According to one aspect of the present invention, an ammonia fuel pretreatment apparatus for an ammonia fuel engine is provided, comprising:

[0008] According to one aspect of the present invention, a nitrogen oxide emission pretreatment device for an ammonia fuel engine is provided, comprising: an ammonia fuel main valve, a mixing device, and a water spraying unit; the ammonia fuel main valve and the mixing device are installed sequentially from front to back on an ammonia fuel supply pipeline between an ammonia fuel supply device and an ammonia fuel consumption device in accordance with the flow direction of ammonia fuel, and the water spraying unit is connected to the mixing device for forming a mixture of ammonia fuel and water within the mixing device.

[0009] Optionally, the mixing device and the water spraying unit can be integrated into one device, or they can be two separate components.

[0010] Optionally, the mixing device includes: an ammonia fuel delivery pipeline and a water delivery pipeline; the water delivery pipeline is connected to the ammonia fuel delivery pipeline and forms a T-junction with the ammonia fuel delivery pipeline; wherein, one end of the ammonia fuel delivery pipeline is connected to the ammonia fuel supply pipeline, one end of the water delivery pipeline is connected to the water spraying unit, one end of the ammonia fuel delivery pipeline and the other end of the water delivery pipeline serve as inlets for inputting ammonia fuel and water, and the other end of the ammonia fuel delivery pipeline serves as an outlet for outputting the mixture of ammonia fuel and water.

[0011] Optionally, the ammonia fuel delivery pipeline and the water delivery pipeline are connected by welding or by flange.

[0012] Optionally, the mixing device includes: an ammonia fuel delivery pipeline and a water delivery pipeline; one end of the water delivery pipeline is connected to the water spraying unit, and the other end of the water delivery pipeline extends into the ammonia fuel delivery pipeline;

[0013] The other end of the water delivery pipeline is a closed structure, and the water delivery pipeline has a spray hole in the part that extends into the ammonia fuel delivery pipeline.

[0014] Optionally, the water spraying unit (3) includes: a water filtration device, a water pump, and a water medium regulating device; wherein, the water pump and the water medium regulating device are installed sequentially from front to back on the water supply pipeline according to the water flow direction; the water pump is used to control the water output; the water filtration device is installed at any position on the water supply pipeline and is used to filter the water to be output; the water medium regulating device regulates the water output according to the nitrogen oxide emission compliance requirements of the ammonia fuel engine under different loads.

[0015] Optionally, the water medium regulating device may be regulated in the following ways: flow rate regulation and / or pressure regulation.

[0016] Optionally, the water spraying unit further includes a water flow metering device, which is located at the rear end of the water medium regulating device.

[0017] According to another aspect of the present invention, a pretreatment method for a nitrogen oxide emission pretreatment device for an ammonia fuel engine as described in any one of the preceding claims is provided, comprising:

[0018] Ammonia fuel enters the mixing unit through the ammonia fuel main valve;

[0019] When the area is within the emission control zone, the water spray unit is activated, injecting water into the mixing device and forming a mixture of ammonia fuel and water within the mixing device.

[0020] The mixture of ammonia fuel and water is transported to the ammonia fuel consumption device through the ammonia fuel supply pipeline, thus completing the pretreatment of the ammonia fuel.

[0021] By adopting the above technical solution, the present invention has at least one of the following beneficial effects compared with the prior art:

[0022] The ammonia fuel pretreatment device and method for ammonia fuel engines provided by this invention differ from existing selective catalytic reduction technology. It can pretreat ammonia fuel by adding different proportions of water to the ammonia fuel according to different loads of the ammonia fuel engine, thereby reducing the amount of nitrogen oxides generated in the emissions of ammonia fuel engines and thus reducing nitrogen oxide emissions to meet emission standards.

[0023] The ammonia fuel pretreatment device and method for ammonia fuel engines provided by this invention can ensure that ammonia fuel is efficiently mixed with water before entering the ammonia fuel engine, meeting its usage requirements. At the same time, it can reduce the generation of nitrogen oxides directly in the combustion stage of the ammonia fuel engine, eliminating the need for exhaust gas treatment of nitrogen oxides generated by the combustion of ammonia fuel engines, such as selective catalytic reduction (SCR, etc.).

[0024] The ammonia fuel pretreatment device and method for ammonia fuel engines provided by this invention eliminate the need for additional equipment for treating nitrogen oxides on the ship, reducing initial investment and subsequent maintenance costs, minimizing volume and weight occupation on board, reducing the risk of chemical leaks, and avoiding management risks. Attached Figure Description

[0025] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0026] Figure 1 This is a schematic diagram of the overall structure of an ammonia fuel pretreatment device for an ammonia fuel engine in a preferred embodiment of the present invention.

[0027] Figure 2This is a schematic diagram of a mixing device in a preferred embodiment of the present invention.

[0028] Figure 3 This is a schematic diagram of another structure of the mixing device in a preferred embodiment of the present invention.

[0029] Figure 4 This is a schematic diagram of the structure of the water spray unit in a preferred embodiment of the present invention.

[0030] In the diagram: 1 is the main ammonia fuel valve, 2 is the mixing device, 3 is the water spray unit, 2-1 is the ammonia fuel delivery pipeline, 2-2 is the water delivery pipeline, 2-3 is the outlet of the mixed fuel after ammonia fuel and water are mixed, and 2-4 is the water spray hole opened in the part of the water delivery pipeline inserted into the ammonia fuel delivery pipeline; 3-1 is the water pump, 3-2 is the water medium regulating device, 3-3 is the metering device, and 3-4 is the water filtration device. Detailed Implementation

[0031] The embodiments of the present invention are described in detail below: These embodiments are implemented based on the technical solution of the present invention, and provide detailed implementation methods and specific operation processes. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention.

[0032] One embodiment of the present invention provides a nitrogen oxide emission pretreatment device for ammonia fuel engines.

[0033] like Figure 1 As shown, the nitrogen oxide emission pretreatment device for ammonia fuel engine provided in this embodiment may include: an ammonia fuel main valve 1, a mixing device 2, and a water spraying unit 3; the ammonia fuel main valve 1 and the mixing device 2 are installed sequentially from front to back on the ammonia fuel supply pipeline between the ammonia fuel supply device and the ammonia fuel consumption device in accordance with the flow direction of ammonia fuel; the water spraying unit 3 is connected to the mixing device 2 and is used to form a mixture of ammonia fuel and water in the mixing device 2.

[0034] In a preferred embodiment, the mixing device 2 and the water spraying unit 3 are integrated into one device, or are two separate components.

[0035] In a preferred embodiment, the mixing device 2 includes: an ammonia fuel delivery pipeline 2-1 and a water delivery pipeline 2-2; the water delivery pipeline 2-2 is connected to the ammonia fuel delivery pipeline 2-1 and forms a T-junction with it; wherein, one end of the ammonia fuel delivery pipeline 2-1 is connected to an ammonia fuel supply pipeline, one end of the water delivery pipeline 2-2 is connected to a water spraying unit 3, one end of the ammonia fuel delivery pipeline 2-1 and the other end of the water delivery pipeline 2-2 respectively serve as inlets for inputting ammonia fuel and water, and the other end of the ammonia fuel delivery pipeline 2-1 serves as an outlet for outputting the mixture of ammonia fuel and water. Figure 2 As shown.

[0036] In a preferred embodiment, the ammonia fuel delivery pipeline 2-1 and the water delivery pipeline 2-2 are connected by welding or by flange.

[0037] In a preferred embodiment, the mixing device 2 includes: an ammonia fuel delivery pipeline 2-1 and a water delivery pipeline 2-2; one end of the water delivery pipeline is connected to the water spraying unit 3, and the other end of the water delivery pipeline extends into the ammonia fuel delivery pipeline;

[0038] The other end of the water delivery pipeline is a closed structure, and the portion of the water delivery pipeline that extends into the ammonia fuel delivery pipeline has spray holes 2-4. For example... Figure 3 As shown.

[0039] In a preferred embodiment, the water spray unit 3 includes: a water filter 3-4, a water pump 3-1, and a water medium regulating device 3-2; wherein, the water pump 3-1 and the water medium regulating device 3-2 are installed sequentially from front to back on the water supply pipeline according to the water flow direction; the water pump 3-1 is used to control the water output; the water filter 3-4 is installed at any position on the water supply pipeline and is used to filter the water to be output; the water medium regulating device 3-2 regulates the water output according to the nitrogen oxide emission compliance requirements of the ammonia fuel engine under different loads, thereby reducing the maximum temperature of in-cylinder detonation by spraying water and blocking the high-temperature conditions for NOx generation. Figure 4 As shown.

[0040] In a preferred embodiment, the water medium regulating device 3-2 can be regulated in the following ways: flow rate regulation and / or pressure regulation.

[0041] In a preferred embodiment, the water spraying unit 3 further includes a water flow metering device 3-3, which is located at the rear end of the water medium regulating device 3-2.

[0042] An embodiment of the present invention also provides a pretreatment method for any of the nitrogen oxide emission pretreatment devices for ammonia fuel engines described in the above embodiments of the present invention, which may include:

[0043] S1, ammonia fuel enters the mixing unit 2 through the ammonia fuel main valve 1;

[0044] S2, when the hydrogen fuel engine of a ship or other vessel is in the emission control area, the water spray unit is turned on, the water spray unit 3 injects water into the mixing device 2, and a mixture of ammonia fuel and water is formed in the mixing device 2;

[0045] S3, the mixture of ammonia fuel and water is transported to the ammonia fuel consumption unit through the ammonia fuel supply pipeline, thus completing the pretreatment of ammonia fuel.

[0046] It should be noted that the steps in the method provided by the present invention can be implemented using corresponding devices, units, etc. in the system. Those skilled in the art can refer to the technical solution of the system to implement the steps of the method. That is, the embodiments in the system can be understood as preferred examples of the method, and will not be elaborated here.

[0047] The technical solutions provided by the above embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. It should be noted that the terms "connection," "linked," and "set" used in this document are not intended to specify or imply a specific location, structure, or operation of the referred element or device, but are merely descriptive. The term "linked" and similar expressions can refer to a direct connection between elements, or the presence of other connecting elements between them.

[0048] like Figure 1 As shown, the nitrogen oxide emission pretreatment device for ammonia fuel engines provided in the above embodiments of the present invention includes: an ammonia fuel main valve 1, a mixing device 2, and a water spraying unit 3. Ammonia fuel enters the mixing device 2 through the ammonia fuel main valve 1 and mixes with water injected by the water spraying unit 3. The mixture of ammonia and water is then transported to the ship's ammonia fuel consumption device, such as for use in an ammonia fuel engine, through the ammonia fuel supply pipeline.

[0049] In some embodiments of the present invention, the mixing device 2 and the water spraying unit 3 can be integrated into a single device or separated into two independent components, which are placed in different locations.

[0050] like Figure 2 As shown, the mixing device 2 can be a pipeline structure in which the ammonia fuel conveying pipeline 2-1 and the water conveying pipeline 2-2 are welded together in a tee configuration, or it can be a pipeline structure in which the tee configuration is flanged. The inlet ends of the ammonia fuel conveying pipeline 2-1 and the water conveying pipeline 2-2 are two inlets in a tee configuration, and the outlet end of the ammonia fuel conveying pipeline 2-1 is one outlet 2-3 in a tee configuration, outputting the mixed fuel of ammonia fuel and water.

[0051] As attached Figure 3The mixing device 2 can also be a structure in which the water conveying pipe 2-2 is inserted into the ammonia fuel conveying pipe 2-1. The part of the water conveying pipe 2-2 inserted into the ammonia fuel conveying pipe 2-1 has water spray holes 2-4 around it to allow the water to mix fully with the ammonia fuel.

[0052] like Figure 4 As shown, the water spray unit 3 includes a water pump 3-1, a water medium regulating device 3-2, and a filter device 3-4. The water medium regulating device 3-2 controls the output of water entering the mixing device (e.g., spray volume, pressure, etc.) according to the nitrogen oxide emission compliance requirements of the ammonia fuel engine under different loads. This water medium regulating device 3-2 can be either flow rate regulating or pressure regulating.

[0053] In some embodiments of the present invention, the water spraying unit 3 further includes a water tank for storing water.

[0054] In some embodiments of the present invention, the mixing of water for combustion can be flexibly controlled by starting and stopping the water pump 3-1, which can meet emission requirements in emission control zones and economic requirements in non-emission control zones.

[0055] In some embodiments of the present invention, the water filtration device 3-4 can be placed before the water pump 3-1, after the water pump 3-1, or after the water medium regulating device 3-2.

[0056] In some embodiments of the present invention, a water flow metering device 3-3 may also be arranged at the rear end of the water medium regulating device 3-2.

[0057] The nitrogen oxide emission pretreatment device for ammonia fuel engines provided in the above embodiments of the present invention differs from the selective catalytic reduction technology for reducing nitrogen oxide emissions from ammonia fuel engines. In the present invention, ammonia fuel is mixed with different proportions of water according to different loads of the ammonia fuel engine. In the combustion chamber, the generation of nitrogen oxides under different loads of the ammonia fuel engine is reduced by lowering the combustion temperature, thereby reducing nitrogen oxide emissions from the ammonia fuel engine to meet emission standards.

[0058] The ammonia fuel pretreatment device and method for ammonia-fueled engines provided in the above embodiments of the present invention can be applied to reduce nitrogen oxide emissions from marine ammonia-fueled engines. The ammonia fuel is mixed with different proportions of water depending on the load of the ammonia fuel consumption device, thereby reducing nitrogen oxide formation in the combustion chamber by lowering the combustion temperature. The ammonia fuel passes through the main ammonia fuel valve and enters the mixing device to mix with water injected by the water spray unit. The mixture of ammonia fuel and water is then supplied to the ship's ammonia fuel consumption device via the ammonia fuel delivery pipeline. Furthermore, the mixing and combustion of water can be flexibly controlled by starting and stopping the pump in the water spray unit. This meets emission requirements in emission control zones and economic requirements in non-emission control zones, conforming to modern engineering needs.

[0059] The ammonia fuel pretreatment device and method for ammonia-fueled engines provided in the above embodiments of the present invention, compared with existing selective catalytic reduction (SCR) technologies for reducing nitrogen oxide emissions, can effectively reduce the generation of nitrogen oxides in the emissions of ammonia-fueled engines, thereby reducing nitrogen oxide emissions from ammonia-fueled engines. It ensures efficient mixing of ammonia fuel with water before entering the ammonia-fueled engine, meeting its operational requirements. Furthermore, in one application of the present invention, nitrogen oxide generation in the ammonia-fueled engine can be reduced directly during the combustion stage, eliminating the need for exhaust aftertreatment of nitrogen oxides generated during combustion, such as selective catalytic reduction (SCR). This eliminates the need for separate exhaust gas treatment devices for nitrogen oxides on board, reducing initial investment and subsequent maintenance costs, reducing the volume and weight occupied on board, lowering the risk of chemical spills, and avoiding management risks.

[0060] Any matters not covered in the above embodiments of the present invention are well-known in the art.

[0061] The specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various modifications or variations within the scope of the claims, which do not affect the essence of the present invention.

Claims

1. An ammonia fuel pretreatment device for an ammonia fuel engine, characterized in that, include: Ammonia fuel main valve (1), mixing device (2) and water spraying unit (3); the ammonia fuel main valve (1) and the mixing device (2) are installed sequentially from front to back on the ammonia fuel supply pipeline between the ammonia fuel supply device and the ammonia fuel consumption device according to the flow direction of ammonia fuel. The water spraying unit (3) is connected to the mixing device (2) and is used to form a mixture of ammonia fuel and water in the mixing device (2). in: The mixing device (2) adopts any of the following structures: The first structure: The mixing device (2) includes: an ammonia fuel delivery pipeline (2-1) and a water delivery pipeline (2-2); the water delivery pipeline (2-2) is connected to the ammonia fuel delivery pipeline (2-1) and forms a three-way structure with the ammonia fuel delivery pipeline (2-1); wherein, one end of the ammonia fuel delivery pipeline (2-1) is connected to the ammonia fuel supply pipeline, one end of the water delivery pipeline (2-2) is connected to the water spraying unit (3), one end of the ammonia fuel delivery pipeline (2-1) and the other end of the water delivery pipeline (2-2) are respectively used as an inlet for inputting ammonia fuel and water, and the other end of the ammonia fuel delivery pipeline (2-1) is used as an outlet for outputting the mixture of ammonia fuel and water; The second structure: the mixing device (2) includes: an ammonia fuel delivery pipeline (2-1) and a water delivery pipeline (2-2); one end of the water delivery pipeline is connected to the water spraying unit (3), and the other end of the water delivery pipeline extends into the ammonia fuel delivery pipeline; the other end of the water delivery pipeline is a closed structure, and the water delivery pipeline has a water spray hole in the part that extends into the ammonia fuel delivery pipeline; The water spray unit (3) includes: a water filtration device (3-4), a water pump (3-1), and a water medium regulating device (3-2); wherein, the water pump (3-1) and the water medium regulating device (3-2) are installed sequentially from front to back on the water supply pipeline according to the water flow direction; the water pump (3-1) is used to control the water output; the water filtration device (3-4) is installed at any position on the water supply pipeline and is used to filter the water to be output; the water medium regulating device (3-2) regulates the water output according to the nitrogen oxide emission compliance requirements of the ammonia fuel engine under different loads.

2. The ammonia fuel pretreatment device for an ammonia fuel engine according to claim 1, characterized in that, The mixing device (2) and the water spraying unit (3) are integrated into one device, or are two separate components.

3. The ammonia fuel pretreatment device for an ammonia fuel engine according to claim 1, characterized in that, The ammonia fuel delivery pipeline (2-1) and the water delivery pipeline (2-2) are connected by welding or by flange.

4. The ammonia fuel pretreatment device for an ammonia fuel engine according to claim 1, characterized in that, The water medium regulating device (3-2) has the following regulating methods: flow rate regulation and / or pressure regulation.

5. The ammonia fuel pretreatment device for an ammonia fuel engine according to claim 1, characterized in that, The water spray unit (3) further includes a water flow metering device (3-3), which is located at the rear end of the water medium regulating device (3-2).

6. A pretreatment method for an ammonia fuel pretreatment device for an ammonia fuel engine according to any one of claims 1-5, characterized in that, include: Ammonia fuel enters the mixing device (2) through the ammonia fuel main valve (1); When in the emission control zone, the water spray unit is turned on and the water spray unit (3) injects water into the mixing device (2) and forms a mixture of ammonia fuel and water in the mixing device (2); The mixture of ammonia fuel and water is transported to the ammonia fuel consumption device through the ammonia fuel supply pipeline, thus completing the pretreatment of the ammonia fuel.

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