Ammonia fuel pipeline system and control method thereof

Abstract

The application discloses an ammonia fuel pipeline system, which comprises a fuel inlet end, a fuel outlet end and a gas source pipeline assembly which are communicated through pipelines; at least two groups of filter pipeline assemblies are further included; the filter pipeline assemblies are connected in parallel with each other; the filter pipeline assemblies are arranged between the fuel inlet end and the fuel outlet end; the ammonia fuel pipeline system further comprises a buffer cavity, a gas permeation mast and a differential pressure detector; the buffer cavity is provided with a buffer inlet and a buffer outlet; the buffer inlet is connected with the filter pipeline assembly in series through a pipeline; the buffer outlet is connected with the gas permeation mast in series through a pipeline; one end of the differential pressure detector is connected with the fuel inlet end, and the other end is connected with the fuel outlet end; the differential pressure detector is connected in parallel with the filter pipeline assembly. The ammonia fuel pipeline system can realize rapid switching of filters and buffer release of liquid ammonia, and improves operation efficiency and operation safety.

Description

Technical Field

[0001] This invention relates to the field of ammonia fuel pipeline technology for marine engineering equipment and ships; specifically, it relates to an ammonia fuel pipeline system and its control method. Background Technology

[0002] In 2018, the International Maritime Organization (IMO) adopted a strategy for reducing greenhouse gas emissions from ships, proposing a vision of achieving zero greenhouse gas emissions in international maritime transport by 2050. Large ships have begun to increasingly convert their main engines from traditional diesel and heavy oil to use various clean and low-carbon energy sources. The use of LNG propulsion is currently the mainstream trend. Compared to traditional diesel propulsion, LNG propulsion can reduce carbon emissions by 20%-25% and nitrogen oxide emissions by 20%-30%. Furthermore, using ammonia fuel (NH3) as fuel, the combustion products are nitrogen (N2) and water (H2O), which can reduce carbon emissions by 100%, and nitrogen oxide emissions directly meet the IMO Tier 3 standard. Therefore, ammonia fuel is considered one of the most promising zero-carbon fuels for the future, aligning with the medium- to long-term trend of green and low-carbon emissions in the international shipping industry.

[0003] Ammonia is liquid at atmospheric pressure below -33°C, and can also be pressurized to make it liquid at room temperature. Currently, the pressure required for shipboard ammonia fuel main engines is generally 80 bar, and the temperature is 25-50°C, supplied in liquid form. Before entering the engine, the fuel needs to pass through a filtration device to remove impurities to prevent damage to the main engine. After prolonged use, the filter cartridge accumulates a lot of impurities, causing blockages, increasing pressure drop, and obstructing the fuel supply line. Filter maintenance requires a long time, during which operation is interrupted, severely impacting work efficiency.

[0004] Furthermore, the filter contains liquid fuel. When the filter is clogged and maintenance is carried out, the liquid ammonia turns into a gaseous state at room temperature, forming an explosive mixture that is flammable and explosive. How to carry out safe maintenance is also an urgent problem to be solved. Summary of the Invention

[0005] The present invention aims to overcome at least one of the defects of the prior art and provide an ammonia fuel pipeline system to achieve rapid filter switching and buffering for liquid ammonia release, thereby improving operational efficiency and operational safety.

[0006] Specifically, this invention discloses an ammonia fuel pipeline system, including a fuel inlet end, a fuel outlet end, and a gas source pipeline assembly connected by pipelines; it also includes at least two sets of filter pipeline assemblies; the filter pipeline assemblies are connected in parallel; the filter pipeline assembly is located between the fuel inlet end and the fuel outlet end; the ammonia fuel pipeline system further includes a buffer chamber, a venting mast, and a differential pressure detector; the buffer chamber has a buffer inlet and a buffer outlet; the buffer inlet is connected in series with the filter pipeline assembly via a pipeline; the buffer outlet is connected in series with the venting mast via a pipeline; one end of the differential pressure detector is connected to the fuel inlet end, and the other end is connected to the fuel outlet end; the differential pressure detector is connected in parallel with the filter pipeline assembly; the gas source pipeline assembly is located between the filter pipeline assembly and the fuel outlet end; multiple valves are provided on the pipeline; when the pressure value measured by the differential pressure detector exceeds a threshold, it is determined that the filter pipeline assembly is blocked; and the switching between the filter pipeline assemblies is achieved by controlling the valves.

[0007] The filter pipeline assembly is mainly used for filtering fuel. The present invention is equipped with at least two sets of filter pipeline assemblies, one set is in operation and the other set is on standby. When the differential pressure detector detects that one set is blocked, the other set can be started. At the same time, the blocked pipeline is inerted by the set air source pipeline assembly, then the pipeline is treated by air, and finally the filter is cleaned.

[0008] The differential pressure detector is connected to the fuel inlet and fuel outlet respectively to detect the pressure difference between the inlet and outlet. It has two signal states: normal differential pressure and high differential pressure. When the differential pressure is less than P1, it displays a normal differential pressure signal to the control panel; when the differential pressure is ≥ P1, it displays a high differential pressure alarm signal to the control panel. The control panel controls the valve to switch the use of the filter pipeline components. When one filter is in use, the other filter is cleaned.

[0009] This invention has two main innovations. First, through a parallel design of dual or even multiple filter pipelines, when one filter pipeline assembly becomes clogged, it can be quickly switched to other parallel filter pipeline assemblies via valve control, without affecting the operating status. During this time, the clogged filter can undergo sequential operations such as fuel release, inerting, purging, and filter cleaning. Second, because there is a momentary high-pressure release during the release of liquid ammonia to the venting mast during the cleaning process, another innovation of this invention is the design of a buffer chamber. When liquid ammonia is released into the buffer chamber, the pressure changes from high pressure to atmospheric pressure, ensuring safety during operation.

[0010] Furthermore, the filter piping assembly comprises two groups: a first filter piping assembly and a second filter piping assembly. The first filter piping assembly includes a first pipe, a first filter, and a second pipe connected in sequence. The first pipe is equipped with a first control valve and a first pressure sensor. The second pipe is equipped with a second control valve. The gas source piping assembly is connected to the second pipe. The second filter piping assembly includes a sixth pipe, an eighth control valve, a second pressure sensor, a second filter, a ninth control valve, and an eighth pipe connected in sequence. A first three-way valve is provided at the junction of the fuel inlet end and the first and sixth pipes. A second three-way valve is provided at the junction of the fuel outlet end and the second and eighth pipes. The first filter piping assembly also includes a third pipe, on which a third control valve is provided. The third pipe is connected to the top of the first filter, and its other end is connected to the buffer inlet. The second filter piping assembly also includes a tenth pipe, on which a tenth control valve is provided. The tenth pipe is connected to the top of the second filter, and its other end is connected to the buffer inlet.

[0011] Furthermore, the first filter piping assembly also includes a fourth pipe, on which a fourth control valve is provided; the upper end of the fourth pipe is connected to the bottom of the first filter; the other end is connected to the buffer inlet; the fourth pipe also has a first branch, which is connected in series with the fuel inlet; the first branch also has a fifth control valve; the second filter piping assembly also includes an eleventh pipe, on which an eleventh control valve is provided; the upper end of the eleventh pipe is connected to the bottom of the second filter; the other end is connected to the buffer inlet; the eleventh pipe also has a second branch, which is connected in series with the fuel inlet; the second branch also has a twelfth control valve.

[0012] Furthermore, the gas source pipeline assembly includes a gas source end, a first gas source pipeline, and a plurality of parallel second gas source pipelines connected in sequence; a sixth control valve is provided on the first gas source pipeline; a seventh control valve and a one-way valve are provided in sequence on the second gas source pipeline; the connection point between the second gas source pipeline and the second pipeline is located between the second control valve and the second three-way valve.

[0013] The one-way valve of this invention is designed to prevent fuel backflow into the gas source.

[0014] Furthermore, the present invention also includes a control panel for remote control of the ammonia fuel pipeline system, wherein the threshold is 1.5 bar to 5 bar; the volume of the buffer chamber is more than 4 times the sum of the volumes of the third pipeline, the fourth pipeline and the first filter; or more than 4 times the sum of the volumes of the tenth pipeline, the eleventh pipeline and the second filter; the working pressure of the pipeline is ≤85 barg and the working temperature range is -45°C to 55°C.

[0015] The present invention also includes a control method for an ammonia fuel pipeline system, comprising:

[0016] S1: When the differential pressure detector shows a differential pressure ≥ P1, it is determined that the first filter is blocked; S2: Disconnect the pipeline where the blocked filter is located and start the filter pipeline assembly connected in parallel with it, that is, start the second filter; S3: Clean the blocked first filter and prepare for restarting the first filter; S4: When the differential pressure detector shows that the differential pressure of the second filter is ≥ P1, switch the line to the unblocked filter pipeline assembly connected in parallel with it, and repeat the above steps S3 to S4.

[0017] Preferably, in step S3, the method for cleaning the filter is as follows:

[0018] T1: Release fuel;

[0019] T2: Using inert gas to replace fuel vapors;

[0020] T3: Replace inert gas with natural air;

[0021] T4: Close the first control valve, the second control valve, the third control valve, and the fourth control valve, and clear the blockage in the first filter;

[0022] The fuel release process in step T1 includes a first-stage filter fuel release process and a second-stage pipeline fuel release process, which are performed sequentially.

[0023] The first stage of the filter fuel release process is as follows: close the first control valve and the second control valve, open the third control valve on the upper side of the first filter, and the fuel in the first filter is released into the buffer chamber through the third pipe, and then enters the venting mast for discharge through the pipeline until the first pressure sensor shows that the pressure is equal to 0 barg;

[0024] The second-stage pipeline fuel release process is as follows: the first control valve and the second control valve are opened, and the third control valve on the upper side of the first filter is opened. The fuel in the pipeline passes through the first filter, and then is released into the buffer chamber through the third pipeline. It then enters the venting mast for discharge through the pipeline until the first pressure sensor shows a pressure of 0 barg. The first-stage filter fuel release process and the second-stage pipeline fuel release process are carried out sequentially to achieve buffering and phase change vaporization of liquefied fuel during the two-stage release operation.

[0025] The method of replacing the fuel vapor gas with inert gas in step T2 is as follows:

[0026] Open the fourth, fifth, sixth, and seventh control valves. Inert gas is purged from the gas source end through the sixth control valve and the second gas source pipeline. Residual liquid fuel and evaporated gas in the first pipeline, the first filter, and the second pipeline are discharged to the ventilated mast through the third pipeline, the fourth pipeline, the first branch, and the buffer chamber.

[0027] According to the control method of claim 7, the method of replacing the inert gas with natural air in step T3 before the first filter is put back into use is as follows:

[0028] Open the first control valve, second control valve, third control valve, fourth control valve, fifth control valve, sixth control valve, and seventh control valve. Compressed natural air starts from the air source end, passes through the sixth control valve and the second air source pipeline for purging, and blows the inert air in the first filter, first pipeline, second pipeline, third pipeline, fourth pipeline, first branch, and buffer chamber to the ventilation mast.

[0029] Furthermore, in step S3, the preparation before restarting the first filter includes the following steps: first, replacing the natural air with inert gas, the operation method is as follows: opening the first control valve, second control valve, third control valve, fourth control valve, fifth control valve, sixth control valve, and seventh control valve, the inert gas starts from the gas source end, passes through the sixth control valve, and is blown out through the second gas source pipeline, blowing the inert gas in the first filter, first pipeline, second pipeline, third pipeline, fourth pipeline, first branch, and buffer chamber to the ventilation mast; then replacing the inert gas with fuel: switching the first A three-way valve disconnects the fifth and sixth pipelines and connects them to the first pipeline, allowing fuel to enter the first filter and the first and second pipelines, replacing the inert gas with fuel. The fourth, fifth, and seventh control valves remain closed, while the third control valve opens to allow the inert gas to exit through the third pipeline to the vent. Finally, the third control valve is closed, and a second three-way valve is switched to disconnect the seventh and eighth pipelines and connect them to the second pipeline, allowing fuel to flow through the fuel inlet, the first filter, and the fuel outlet. The differential pressure detector displays a differential pressure ≤ P1.

[0030] The filters, their corresponding control valves, and auxiliary pipelines of this invention are configured redundantly. When one filter needs cleaning, the system switches to the other filter, and vice versa. The specific operating methods are the same when different filters need cleaning. In one embodiment of this invention, two sets of filter pipeline assemblies are provided in parallel. The operating method for cleaning the first filter is as follows:

[0031] When the first filter is in use, the differential pressure detector shows a differential pressure ≥ P1, indicating that the first filter is blocked. Switch the first three-way valve and the second three-way valve to disconnect the first and second pipelines, and at the same time connect the parallel filter pipeline assembly; the fuel is switched from being filtered through the first filter to being filtered through the parallel filter before entering the fuel outlet.

[0032] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0033] (1) The present invention provides a fuel pipeline with a switchable dual filter and a differential pressure detector. The differential pressure detector can detect the working status of the filter, determine whether it is blocked, and quickly switch the filter pipeline to improve working efficiency.

[0034] (2) This invention can be purged and replaced using either inert gas or natural air as a gas source, for cleaning residual fuel in the device or for safe replacement for reuse. At the same time, a buffer chamber is set up to buffer and phase change vaporization during the release, inerting, purging, and residual discharge operations. The volume of the buffer chamber is sufficient for the buffer release of the filter and its pipeline, which improves the safety of the operation and avoids the safety hazard of explosion.

[0035] (3) The ammonia fuel pipeline system of the present invention has a maximum working pressure of 85 barg and a working temperature of -45℃ to 50℃, and is suitable for both LPG (liquefied petroleum gas) and LNH3 (liquid ammonia).

[0036] (4) In particular, considering that ammonia fuel is easy to vaporize and is toxic at normal temperature and pressure, the filter cleaning and maintenance process has a two-stage shut-off, release and inerting process with a three-way valve and two control valves at both ends of the filter to prevent fuel leakage. The control methods during cleaning and before use are proposed to improve and ensure safety during operation. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the pipeline layout of the ammonia fuel pipeline system of the present invention.

[0038] Figure 2 This is a schematic diagram of the flow direction of the three-way valve in the ammonia fuel pipeline system of the present invention. Detailed Implementation

[0039] The accompanying drawings illustrate the technical solutions of the embodiments of the present invention in more detail. Throughout the drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions. The described embodiments are some, but not all, embodiments of the present invention. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention. The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0040] It should be noted that if the embodiments of this application involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0041] Furthermore, if the embodiments of this application involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0042] Example

[0043] This embodiment improves an ammonia fuel pipeline system with two sets of filter pipeline assemblies.

[0044] like Figure 1As shown, an ammonia fuel pipeline device includes the following components: a control panel 100, a fuel inlet end 101, a fuel outlet end 102, a gas source end 103, a buffer chamber 104, a differential pressure detector 105, a venting mast 106, a first filter 201, a second filter 202, a first three-way valve 301, a second three-way valve 302, a first control valve 311, a second control valve 318, a third control valve 310, a fourth control valve 312, a fifth control valve 316, a sixth control valve 322, and a seventh control valve 321; a first check valve 341, a second check valve 342, and a connecting pipe. The system includes a first pipe 403, a second pipe 405, a third pipe 407, a fourth pipe 409, a sixth pipe 404, an eighth control valve 314, a ninth control valve 319, an eighth pipe 406, a tenth pipe 408, and a tenth control valve 313. The tenth pipe 408 is connected to the top of the second filter 202, and the other end is connected to the buffer inlet. A first pressure sensor 431 and a second pressure sensor 432 switch when the differential pressure detector 105 reaches a set value. The clogged filter can be sequentially subjected to operations such as fuel release, inerting, purging, and filter cleaning. The first check valve 341 and the second check valve 342 are used to prevent fuel backflow into the gas source end 103; it also includes an eleventh pipe 410, on which an eleventh control valve 315 is provided; the upper end of the eleventh pipe 410 is connected to the bottom of the second filter 202; the other end is connected to the buffer inlet; the eleventh pipe 410 is also provided with a second branch 414, which is connected in series with the fuel inlet end 101; the second branch 414 is also provided with a twelfth control valve 317.

[0045] The differential pressure detector 105 is connected to the fuel inlet 101 and the fuel outlet 102 respectively to detect the differential pressure between the inlet and outlet. It has two signal states: normal differential pressure and high differential pressure. When the differential pressure is less than P1, it displays a normal differential pressure signal to the control panel; when the differential pressure is ≥ P1, it displays a high differential pressure alarm signal to the control panel. The control panel controls the first three-way valve 301 and the second three-way valve 302 to switch between the first filter 201 and the second filter 202. When one filter is in use, the other filter is cleaned. In this embodiment, the adjustable range of P1 is 1.5 bar to 5 bar.

[0046] The first filter 201, the second filter 202, and their corresponding control valves and auxiliary pipelines are configured in a redundant manner. When the first filter 201 needs cleaning, it is switched to the second filter 202, and vice versa. The specific operating methods for cleaning the first filter 201 and the second filter 202 are the same. The following is the operating method for cleaning the first filter 201:

[0047] When the first filter 201 is in use, the differential pressure detector 105 detects and displays a differential pressure ≥ P1, indicating that the first filter 201 is blocked.

[0048] Combination Figure 2 As shown, the first three-way valve 302 is switched to disconnect the fifth pipeline 401 from the first pipeline 403 and connect the fifth pipeline 401 to the sixth pipeline 404; the second three-way valve 301 is switched to disconnect the seventh pipeline 402 from the second pipeline 405 and connect the seventh pipeline 402 to the eighth pipeline 406. The fuel is switched from being filtered by the first filter 201 to being filtered by the second filter 202 before entering the fuel outlet 102.

[0049] Then, close the first control valve 311 and the second control valve 318, and open the third control valve 310 to close the inlet and outlet of the first filter 201 and open the venting channel. The fuel in the first filter 201 is released through the third pipe 407, enters the buffer chamber 104, and then enters the venting mast 106 through the ninth pipe 413. During the release process, the ammonia fuel changes from high pressure to normal pressure, and the liquid ammonia undergoes a phase change to gaseous ammonia, which is then discharged through the venting mast 106. Release continues for a period of time until the first pressure sensor 431 displays 0 barg.

[0050] The first control valve 311 and the second control valve 318 are further opened to discharge liquid ammonia from the first pipeline 403 and the second pipeline 405 to the vent mast 106 until the first pressure sensor 431 displays 0 barg.

[0051] Then, inert gas is used to replace the fuel vapor gas. The operation method is as follows: the sixth control valve 322, the seventh control valve 321, the fourth control valve 312, and the fifth control valve 316 are further opened. The inert gas starts from the gas source end 103, passes through the sixth control valve 322, and is inertized and purged through the second gas source pipeline 411. The residual liquid fuel and vapor gas in the first filter 201, the first pipeline 403, and the second pipeline 405 are discharged to the ventilated mast 106 through the third pipeline 407, the fourth pipeline 409, the first branch 412, and the buffer chamber 104.

[0052] Then replace the inert gas with natural air: open the first control valve 311, the second control valve 318, the third control valve 310, the fourth control valve 312, the fifth control valve 316, the sixth control valve 322, and the seventh control valve 321. Compressed natural air starts from the air source end 103 and is blown out by the sixth control valve 322 and the second air source pipeline 411, blowing out the inert gas in the first filter 201, the first pipeline 403, the second pipeline 405, the third pipeline 407, the fourth pipeline 409, the first branch 412, and the buffer chamber 104 to the ventilation mast.

[0053] Finally, close the first control valve 311, the second control valve 318, the third control valve 310, and the fourth control valve 312, and perform maintenance on the first filter 201 to clean out any blockages.

[0054] The operation steps for putting the first filter 201 into use in this embodiment are as follows:

[0055] First, inert gas is used to replace the natural air. The operation method is as follows: open the first control valve 311, the second control valve 318, the third control valve 310, the fourth control valve 312, the fifth control valve 316, the sixth control valve 322, and the seventh control valve 321. The inert gas starts from the gas source end 103, passes through the sixth control valve 322, and is blown out through the second gas source pipeline 411. The inert gas in the first filter 201, the first pipeline 403, the second pipeline 405, the third pipeline 407, the fourth pipeline 409, the first branch 412, and the buffer chamber 104 is blown out to the ventilation mast.

[0056] The inert gas is replaced with fuel. Switch the first three-way valve 302 to disconnect the fifth pipeline 401 from the sixth pipeline 404 and connect it to the first pipeline 403. Fuel enters the first filter 201 and the first pipeline 403 and the second pipeline 405, replacing the inert gas with fuel. Keep the fourth control valve 312, the fifth control valve 316, and the seventh control valve 321 closed, and open the third control valve 310 to allow the inert gas to be discharged through the third pipeline 407 to the vent mast 106.

[0057] Close the third control valve 310 and switch the second three-way valve 301 to disconnect the seventh pipe 402 from the eighth pipe 406 and connect it to the second pipe 405. Fuel flows through the fuel inlet 101, the first filter 201, and the fuel outlet 102. The differential pressure detector 105 detects and displays that the differential pressure is ≤P1.

[0058] Once the first filter 201 is cleaned, it can be put into use. When the second filter 202 becomes clogged, the method of this embodiment can be followed to switch the first filter 201 into use, and then the method of this embodiment can be followed to release fuel, replace inert gas and air, and clean and pre-treat the second filter 202 before it is put into use again.

[0059] The buffer chamber 104 designed in this invention allows the medium to enter the buffer chamber 104 after the confluence of the third pipe 407 and the fourth pipe 409. The buffer chamber 104 has an outlet discharge ninth pipe 413. Its features and functions are to buffer and perform phase change vaporization during operations such as release, inerting, purging, and residual discharge. The volume of the buffer chamber 104 is more than 4 times the sum of the volumes of the third pipe 407, the fourth pipe 409, and the first filter 201, or more than 4 times the sum of the volumes of the tenth pipe (408), the eleventh pipe (410), and the second filter (202).

[0060] Furthermore, the pipeline used in this invention has a working pressure of ≤85 barg and a working temperature range of -45℃ to 55℃.

[0061] The present invention has a control panel 100, which can realize the monitoring and remote control of the differential pressure detector 105, the second three-way valve 301, the first three-way valve 302, all the above-mentioned control valves, as well as the first pressure sensor 431 and the second pressure sensor 432.

[0062] The above embodiments are merely illustrative of the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to the preferred embodiments above, those skilled in the art should understand that modifications or equivalent substitutions to the technical solutions of the present invention should not depart from the spirit and scope of the present invention. Those skilled in the art can also make other changes within the spirit of the present invention and use them in the design of the present invention, as long as they do not deviate from the technical effects of the present invention. These changes made according to the spirit of the present invention should all be included within the scope of protection claimed by the present invention.

Claims

1. An ammonia fuel pipeline system, comprising a fuel inlet (101), a fuel outlet (102), and a gas source pipeline assembly connected by pipelines; characterized in that, It also includes at least two sets of filter piping assemblies; the filter piping assemblies are connected in parallel with each other; The filter piping assembly is located between the fuel inlet end and the fuel outlet end; The ammonia fuel pipeline system also includes a buffer chamber (104), a ventilation mast (106), and a differential pressure detector (105). The buffer chamber (104) is provided with a buffer inlet and a buffer outlet. The buffer inlet is connected in series with the filter piping assembly via a pipe; the buffer outlet is connected in series with the ventilated mast (106) via a pipe; One end of the differential pressure detector (105) is connected to the fuel inlet (101), and the other end is connected to the fuel outlet (102); the differential pressure detector (105) is connected in parallel with the filter pipeline assembly; The gas source pipeline assembly is located between the filter pipeline assembly and the fuel outlet end (102); The pipeline is equipped with multiple valves. When the pressure value exceeds the threshold measured by the differential pressure detector (105), the filter pipeline assembly is determined to be blocked. Then, by controlling the valves, the filter pipeline assembly can be switched between each other. While one filter is in use, the other filter is cleaned. The cleaning method is as follows: T1: Release fuel; T2: Using inert gas to replace fuel vapors; T3: Replace inert gas with natural air; T4: Clean the blockage inside the filter; The fuel release process in step T1 includes a first-stage filter fuel release process and a second-stage pipeline fuel release process, which are performed sequentially. The first stage of the filter fuel release process is as follows: close the first control valve (311) and the second control valve, open the third control valve (310) on the upper side of the first filter (201), and the fuel in the first filter (201) is released into the buffer chamber through the third pipe (407), and then enters the ventilation mast (106) through the pipeline for discharge until the first pressure sensor (431) shows that the pressure is equal to 0 barg; The second stage of pipeline fuel release process is as follows: the first control valve (311) and the second control valve (318) are opened, and the third control valve (310) on the upper side of the first filter (201) is opened. The fuel in the pipeline passes through the first filter (201) and is released into the buffer chamber (104) through the third pipe (407). Then it enters the ventilation mast (106) through the pipeline for discharge until the first pressure sensor (431) shows that the pressure is equal to 0 barg. The first stage filter fuel release process and the second stage pipeline fuel release process are carried out in sequence to realize the buffering and phase change vaporization of liquefied fuel in the two-stage release operation.

2. The ammonia fuel pipeline system according to claim 1, characterized in that, The filter piping assembly consists of two groups, namely a first filter piping assembly and a second filter piping assembly; the first filter piping assembly includes a first pipe (403), a first filter (201), and a second pipe (405) connected in sequence; a first control valve (311) and a first pressure sensor (431) are provided on the first pipe (403); a second control valve (318) is provided on the second pipe (405); the gas source piping assembly is connected to the second pipe (405). The second filter piping assembly includes a sixth pipe (404), an eighth control valve (314), a second pressure sensor (432), a second filter (202), a ninth control valve (319), and an eighth pipe (406) connected in sequence. A first three-way valve (302) is provided at the junction of the fuel inlet end (101) and the first pipe (403) and the sixth pipe (404); a second three-way valve (301) is provided at the junction of the fuel outlet end (102) and the second pipe (405) and the eighth pipe (406). The first filter piping assembly further includes a third pipe (407), on which a third control valve (310) is provided; the third pipe (407) is connected to the top end of the first filter (201); the other end is connected to the buffer inlet; The second filter piping assembly also includes a tenth pipe (408), on which a tenth control valve (313) is provided; the tenth pipe (408) is connected to the top end of the second filter (202); the other end is connected to the buffer inlet.

3. The ammonia fuel pipeline system according to claim 2, characterized in that, The first filter piping assembly further includes a fourth pipe (409), on which a fourth control valve (312) is provided; the upper end of the fourth pipe (409) is connected to the bottom of the first filter (201); the other end is connected to the buffer inlet; the fourth pipe (409) is also provided with a first branch (412), which is connected in series with the fuel inlet end (101); the first branch (412) is also provided with a fifth control valve (316). The second filter piping assembly also includes an eleventh pipe (410), on which an eleventh control valve (315) is provided; the upper end of the eleventh pipe (410) is connected to the bottom of the second filter (202); the other end is connected to the buffer inlet; The eleventh pipeline (410) is also provided with a second branch (414), which is connected in series with the fuel inlet end (101); the second branch (414) is also provided with a twelfth control valve (317).

4. The ammonia fuel pipeline system according to claim 3, characterized in that, The gas source pipeline assembly includes a gas source end (103), a first gas source pipeline, and a plurality of parallel second gas source pipelines connected in sequence; a sixth control valve (322) is provided on the first gas source pipeline; a seventh control valve (321) and a one-way valve (341) are provided in sequence on the second gas source pipeline; the connection point between the second gas source pipeline (411) and the second pipeline (405) is located between the second control valve (318) and the second three-way valve (301).

5. The ammonia fuel pipeline system according to claim 4, characterized in that, It also includes a control panel (100) for remote control of the ammonia fuel pipeline system, wherein the threshold is 1.5 bar to 5 bar; the volume of the buffer chamber (104) is more than 4 times the sum of the volumes of the third pipeline (407), the fourth pipeline (409) and the first filter (201); or more than 4 times the sum of the volumes of the tenth pipeline (408), the eleventh pipeline (410) and the second filter (202); the working pressure of the pipeline is ≤85 barg and the working temperature range is -45°C to 55°C.

6. A control method for an ammonia fuel pipeline system as described in any one of claims 1 to 4, characterized in that, include: S1: When the differential pressure detector shows a differential pressure ≥ P1, it is determined that the first filter (201) is blocked; S2: Disconnect the pipeline where the blocked filter is located and start the filter pipeline assembly connected in parallel with it, that is, start the second filter (202); S3: Cleaning the clogged first filter and preparing for the re-engagement of the first filter (201); S4: When the differential pressure detector (105) shows that the differential pressure of the second filter (202) is ≥ P1, switch the line to the unblocked filter pipeline assembly connected in parallel, and repeat the above steps S3~S4.

7. The control method according to claim 6, characterized in that, In step S3, the method for cleaning the filter is as follows: T1: Release fuel; T2: Using inert gas to replace fuel vapors; T3: Replace inert gas with natural air; T4: Close the first control valve (311), the second control valve (318), the third control valve (310), and the fourth control valve (312), and clean the blockage in the first filter (201); The fuel release process in step T1 includes a first-stage filter fuel release process and a second-stage pipeline fuel release process, which are performed sequentially. The first stage of the filter fuel release process is as follows: close the first control valve (311) and the second control valve, open the third control valve (310) on the upper side of the first filter (201), and the fuel in the first filter (201) is released into the buffer chamber through the third pipe (407), and then enters the ventilation mast (106) through the pipeline for discharge until the first pressure sensor (431) shows that the pressure is equal to 0 barg; The second stage of pipeline fuel release process is as follows: the first control valve (311) and the second control valve (318) are opened, and the third control valve (310) on the upper side of the first filter (201) is opened. The fuel in the pipeline passes through the first filter (201), and then is released into the buffer chamber (104) through the third pipe (407). Then it enters the ventilation mast (106) through the pipeline for discharge until the first pressure sensor (431) shows that the pressure is equal to 0 barg. The first stage filter fuel release process and the second stage pipeline fuel release process are carried out in sequence to realize the buffering and phase change vaporization of liquefied fuel in the two-stage release operation. The method of replacing the fuel vapor gas with inert gas in step T2 is as follows: Open the fourth control valve (312), the fifth control valve (316), the sixth control valve (322), and the seventh control valve (321). Inert gas is blown out from the gas source end (103) through the sixth control valve (322) and the second gas source pipeline (411). The residual liquid fuel and evaporated gas in the first pipeline (403), the first filter (201), and the second pipeline (405) are discharged to the ventilated mast (106) through the third pipeline (407), the fourth pipeline (409), the first branch (412), and the buffer chamber (104).

8. The control method according to claim 7, characterized in that, The method of replacing the inert gas with natural air in step T3, which is used to prepare the first filter (201) for reuse, is as follows: Open the first control valve (311), the second control valve (318), the third control valve (310), the fourth control valve (312), the fifth control valve (316), the sixth control valve (322), and the seventh control valve (321). Compressed natural air starts from the air source end (103), passes through the sixth control valve (322) and the second air source pipeline (411) to blow out the inert air in the first filter (201), the first pipeline (403), the second pipeline (405), the third pipeline (407), the fourth pipeline (409), the first branch (412), and the buffer chamber (104) to the ventilation mast (106).

9. The control method according to claim 6, characterized in that, In step S3, the preparation for re-putting the first filter (201) includes the following steps: First, replace the natural air with inert gas. The operation method is as follows: open the first control valve (311), the second control valve (318), the third control valve (310), the fourth control valve (312), the fifth control valve (316), the sixth control valve (322), and the seventh control valve (321). The inert gas starts from the gas source end (103), passes through the sixth control valve (322), and is blown out through the second gas source pipeline (411). The inert gas in the first filter (201), the first pipeline (403), the second pipeline (405), the third pipeline (407), the fourth pipeline (409), the first branch (412), and the buffer chamber (104) is blown out to the ventilation mast (106). Replace the inert gas with fuel: Switch the first three-way valve (302) to disconnect the fifth pipeline (401) from the sixth pipeline (404) and connect it to the first pipeline (403). Fuel enters the first filter (201) and the first pipeline (403) and the second pipeline (405) to replace the inert gas with fuel. Keep the fourth control valve (312), the fifth control valve (316), and the seventh control valve (321) closed, and the third control valve (310) open to allow the inert gas to be discharged to the ventilation mast (106) through the third pipeline (407). Finally, close the third control valve (310) and switch the second three-way valve (301) to disconnect the seventh pipeline (402) from the eighth pipeline (406) and connect it to the second pipeline (405). The fuel flows through the fuel inlet (101), the first filter (201), and the fuel outlet (102). The differential pressure detector (105) detects and displays that the differential pressure is ≤P1.

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