A test tool and method for a marine dual-fuel diesel engine gas control block airtight test

Abstract

The application discloses a kind of test tool and method of marine dual-fuel diesel engine gas control block airtight test.The tool includes core components such as adaptive flange, silencer, ball valve assembly, sealing assembly and diaphragm accumulator, and replaces traditional chain pipe system through innovative modular design.Adaptive flange integrates multi-path oil hole system, including high-pressure oil supply hole, low-pressure oil supply hole, sealing oil hole and gas supply hole, and realizes efficient sealing with special sealing structure.Test method adopts staged pressure test, including low-pressure oil, high-pressure oil, sealing oil and gas four-stage test, and ensures test accuracy by accurately controlling pressure parameters and pressure maintaining time.The application solves the problems of traditional test method, such as complex installation and low efficiency, shortens test time by more than 73%, and sealing detection accuracy reaches 1x10 ‑6 mbar·L / s level, significantly improves test safety and reliability, and is suitable for airtightness detection of various marine dual-fuel engine gas control blocks.

Description

Technical Field

[0001] This invention relates to the field of testing gas systems for marine dual-fuel diesel engines, specifically to a test fixture and method for testing the air tightness of a gas control block in a marine dual-fuel diesel engine. This fixture replaces the normal adapter and chain pipe during the air tightness test of a single cylinder of a dual-fuel diesel engine, so as to facilitate the rapid and accurate completion of the single-cylinder air tightness test. Background Technology

[0002] Marine dual-fuel diesel engines can operate in two fuel modes: fuel oil and natural gas. For dual-fuel diesel engines, the airtightness of the gas system is particularly important; a gas leak could cause irreparable damage. Therefore, airtightness tests are required for the gas components in each cylinder of the dual-fuel diesel engine. To conduct these tests, the gas control block, window valve, and gas injection valve must first be installed on the cylinder head according to the installation requirements. The gas control block needs to be connected to its corresponding adapter and chain hoses, among other gas components, for airtightness testing.

[0003] If an airtightness test is performed after the gas control block, window valve, and chain pipe, etc., are installed, the following problems will occur:

[0004] 1. The installation of gas components such as gas control blocks, window valves, and chain pipes requires high technical skills, involves complex operating steps and specific process requirements, and is cumbersome to operate.

[0005] 2. After the gas control block, window valve, chain pipe and other gas components are fully installed, they occupy a huge area, which is inconvenient for on-site construction. In addition, each cylinder gas control block needs to be tested for air tightness, and the chain pipe needs to be adjusted continuously to meet the air tightness requirements of a single cylinder. Improper operation will have an adverse effect on the safety and accuracy of the single cylinder air tightness test.

[0006] 3. For cylinder heads containing gas components such as gas control blocks, window valves, and chain pipes, the entire unit cannot be hoisted and installed after the air tightness test. It is necessary to disassemble and reinstall the entire unit using the diesel engine installation process, resulting in repeated disassembly and reassembly.

[0007] Currently, no descriptions or reports of technologies similar to this invention have been found, and no similar information has been collected domestically or internationally. Summary of the Invention

[0008] To address the aforementioned shortcomings in the prior art, this invention provides a test fixture and method for testing the airtightness of the gas control block of a marine dual-fuel diesel engine.

[0009] A test fixture for airtightness testing of the gas control block of a marine dual-fuel diesel engine, characterized in that it includes:

[0010] The adapter flange (2) is provided with:

[0011] Four first threaded holes evenly distributed on the upper end face are used for bolt connection with the gas control block (102);

[0012] Four second threaded holes are evenly distributed on the outer circumference for installing eye bolts (10);

[0013] The third threaded hole on the left end face is used to connect the diaphragm accumulator (13);

[0014] The fourth threaded hole on the rear end face is used to connect the ball valve assembly (5);

[0015] The lower end face is provided with a pipe interface for connecting a three-way valve (11);

[0016] A gas detection hole (21) is provided on the side end face, and a removable screw plug (6) is provided on its outer port.

[0017] The lower end face is also provided with a sealing oil hole (22), a drain oil hole (23), a high-pressure oil supply hole (24), a low-pressure oil supply hole (25), and a gas supply hole (26); the high-pressure oil supply hole (24) has a T-shaped structure, with its first port connected to the pump pressure equipment and its second port connected to the diaphragm accumulator (13); the sealing oil hole (22) and the low-pressure oil supply hole (25) have an L-shaped structure, with their first ports connected to the pump pressure equipment and their second ports connected to the ball valve assembly (5); the gas supply hole (26) has a T-shaped structure, with its first port connected to the pump pressure equipment and its second port connected to the gas control block (102).

[0018] Furthermore, the gas detection hole (21) and the gas supply hole (26) are connected through an internal channel to form a detection path.

[0019] Furthermore, it also includes:

[0020] The silencing device consists of a reducing connector (3), a muffler (4), and a three-way valve (11) connected in sequence;

[0021] The sealing assembly includes a sealing ring (7), a sealing ring (8), and a square cross-section sealing ring (9) disposed between the adapter flange (2) and the gas control block (102).

[0022] Furthermore, the working pressure range of the high-pressure oil supply hole (24) is 0-320 bar, and the hole diameter tolerance is ±0.01 mm.

[0023] An airtightness test method using the above-mentioned test fixture, characterized by comprising the following steps:

[0024] S1. Installation Preparation:

[0025] Connect the gas control block (102) to the adapter flange (2) with bolts, and tighten the bolts to a torque of 80-100 N·m;

[0026] Check the installation status of the sealing ring (7), sealing ring (8) and square cross-section sealing ring (9);

[0027] S2. Pipeline connection:

[0028] Connect the high-pressure oil circuit of the pump pressure equipment to the high-pressure oil supply port (24);

[0029] Connect the low-pressure oil circuit of the pump to the low-pressure oil supply port (25);

[0030] Connect the sealing oil circuit of the pump pressure equipment to the sealing oil hole (22);

[0031] Connect the gas pipeline of the pump to the gas supply port (26);

[0032] S3. Graded stress test:

[0033] a) Low-pressure oil test: Stabilize the pressure to 5±0.1 bar, hold the pressure for 5 minutes, and the pressure drop ≤0.75 bar is acceptable;

[0034] b) High-pressure oil test: Stabilize the pressure to 300±1 bar, hold the pressure for 5 minutes, and the pressure drop ≤0.75 bar is considered qualified;

[0035] c) Sealing oil test: Stabilize the pressure to 320±1 bar, hold the pressure for 5 minutes, and the pressure drop ≤0.75 bar is considered qualified;

[0036] d) Gas test: The pressure is gradually increased to 300±1 bar in 50 bar increments, and the pressure is stabilized for 30-60 seconds at each increment. Finally, the pressure is maintained for 5 minutes. The pressure drop is ≤0.75 bar to be considered qualified.

[0037] Furthermore, in the gas test of step S3, when an abnormal pressure is detected, the following operation is automatically performed: the oil circuit is cut off within 0.5 seconds via the ball valve assembly (5);

[0038] Start the muffler consisting of a reducing connector (3), a muffler (4), and a three-way valve (11);

[0039] Trigger an audible and visual alarm signal.

[0040] A computer-readable storage medium storing a computer program thereon, characterized in that, when the program is executed by a processor, it implements automatic control of the above-described airtightness test method, including:

[0041] Real-time acquisition and processing of pressure data;

[0042] Automatic sequence control of the testing process;

[0043] Automatic identification and handling of abnormal situations;

[0044] Automatic generation of test reports.

[0045] Compared with the prior art, the present invention has the following beneficial effects:

[0046] When conducting airtightness tests using an adapter flange, the gas control block does not need to be installed with the chain pipe. The adapter flange can replace the normal adapter and chain pipe to complete the airtightness test of the gas control block, thereby reducing the workload of the test and improving the work efficiency. At the same time, it effectively reduces the complex operation steps and specific process requirements involved in the installation process, thereby reducing the difficulty of the test preparation stage and the installation difficulty.

[0047] It allows for individual airtightness testing of each cylinder without the need to link it to other components, simplifying the airtightness testing process and effectively avoiding the need to constantly adjust the chain tube to meet the airtightness requirements of a single cylinder, thereby ensuring the safety and accuracy of the airtightness test.

[0048] It can be installed by single-cylinder hoisting after the airtightness test is completed, and has the characteristics of simple structure, easy operation and convenient use.

[0049] It meets the airtightness test requirements of the gas control block. This makes the airtightness test of the gas block of marine dual-fuel low-speed diesel engine simpler, faster, and more accurate, reducing the need for repeated disassembly and assembly of other components, thus saving manpower and resources.

[0050] This invention fills the gap in existing test fixtures and methods for testing the air tightness of the gas control block of a dual-fuel diesel engine, thereby improving work efficiency. Attached Figure Description

[0051] 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:

[0052] Figure 1 This is a schematic diagram of the test fixture for the airtightness test of the gas control block of the marine dual-fuel diesel engine of the present invention.

[0053] Figure 2 This is a side view of the test fixture for the airtightness test of the gas control block of the marine dual-fuel diesel engine of the present invention;

[0054] Figure 3 This is a cross-sectional view of the flange adapted to this invention;

[0055] Figure 4This is a schematic diagram of the opening of the flange adapted to this invention;

[0056] Figure 5 This is a schematic diagram of the installation of the test fixture for the gas control block airtightness test of the present invention;

[0057] In the diagram: 1. Adapter flange; 2. Fitting flange; 3. Reducer; 4. Silencer; 5. Ball valve assembly; 6. Plug; 7. Sealing ring; 8. Sealing ring; 9. Square cross-section sealing ring; 10. Eye bolt; 11. Three-way stopcock; 12. Pipe fitting; 13. Diaphragm accumulator; 21. Gas detection port; 22. Sealing oil port; 23. Drain oil port; 24. High-pressure oil supply port; 25. Low-pressure oil supply port; 26. Gas supply port; 102. Gas control block; 103. Cylinder head; 104. Injection valve; 105. Control oil; 106. Test bench Detailed Implementation

[0058] 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.

[0059] like Figure 1 As shown, a test fixture for airtightness testing of a marine dual-fuel diesel engine's gas control block includes: an adapter flange 1, which houses a fitting flange 2, a reducing fitting 3, a muffler 4, a ball valve assembly 5, a screw plug 6, a sealing ring 7, a sealing ring 8, a square cross-section sealing ring 9, a lifting eye screw 10, a three-way valve 11, a pipe fitting 12, and a diaphragm accumulator 13; wherein:

[0060] The upper end of the adapter flange 1 is connected to the gas control block 102, the upper end of the gas control block 102 is connected to the control oil high pressure pipe 105, the rear end is connected to the cylinder head 103, the lower end of the cylinder head 103 is fixed on the test bench 106, and the upper end is connected to the jet valve 104. The jet valve 104 is connected to the control oil high pressure pipe 105.

[0061] The adapter flange 2 is used in place of the conventional adapter and chain pipe for the gas control block 102 during the airtightness test;

[0062] The reducing pipe fitting 3, the silencer 4, and the three-way valve 11 together form a silencing device, which is used to reduce noise when an alarm is triggered during the airtightness test;

[0063] Ball valve assembly 5 is used to prevent high-pressure or low-pressure oil leakage during airtightness testing;

[0064] Plug 6 is used to seal the gas detection port;

[0065] Sealing ring 7, sealing ring 8, and square cross-section sealing ring 9 are used for sealing when the gas control block 102 is connected to the adapter flange 1;

[0066] Eye bolt 10 is used to lift adapter flange 1;

[0067] Pipe fitting 12 is used to connect to each test piping system during the airtightness test;

[0068] The diaphragm accumulator 13 is used to stabilize oil pressure, absorb pressure, and buffer in the oil circuit;

[0069] In the working state, first, fix the cylinder head on the test bench, install the injection valve on the cylinder head, then correctly install the gas control block to the cylinder head. Next, install one end of the control oil high-pressure pipe to the gas control block and the other end to the injection valve. Finally, install the adapter flange on the lower end of the gas control block, and then conduct a single-cylinder air tightness test. During the test...

[0070] The adapter flange 2 has four evenly distributed threaded holes at its upper end. The threaded holes of the adapter flange 2 are connected to the gas control block 102 by bolts. The outer side of the adapter flange 2 has four threaded holes for installing eye bolts 10. In this embodiment, the four eye bolts 10 are evenly distributed, which enables the distributor flange 1 to be lifted and transported smoothly, preventing damage due to lifting and transportation.

[0071] The left end of the adapter flange 2 is fixedly connected to the diaphragm accumulator 13 by bolts. The left end and rear end of the adapter flange 2 are fixedly connected to the ball valve assembly 5 by bolts. The lower end of the adapter flange 2 is connected to the three-way valve 11 through a pipe interface. The three-way valve 11 is connected to the silencer 4 through a reducing connector 3. In this embodiment, when the airtightness test is carried out, the diaphragm accumulator 13 stabilizes the oil pressure to ensure that the adapter flange 2 will not be damaged due to excessive pressure during the airtightness test. The silencer 4 can reduce noise if an alarm is triggered due to excessive pressure during the airtightness test, preventing test personnel from suffering hearing damage due to noise during the test.

[0072] The lower end of the adapter flange 2 is provided with 6 sealing oil holes 22, drain oil holes 23, high-pressure oil supply holes 24, low-pressure oil supply holes 25, and gas supply holes 26, which are connected to the piping system required for the test. The front end and left end of the adapter flange 2 are respectively provided with gas detection holes 21. In this embodiment, in the early stage of preparing for the airtightness test, it should be ensured that the sealing oil holes 22, drain oil holes 23, high-pressure oil supply holes 24, low-pressure oil supply holes 25, and gas supply holes 26 in the adapter flange 2 are unobstructed and connected to the corresponding piping system used for the test.

[0073] The adapter flange 2 has a gas detection hole 21 on one side and a plug 6 for sealing at the outer opening. The other end of the gas detection hole 21 is connected to the gas supply hole 26. During gas detection, the plug 6 is unscrewed for gas detection. The adapter flange 2 has an oil drain hole 23, a high-pressure oil supply hole 24, and a gas supply hole 26 at the lower end. The other end of the gas supply hole 26 is equipped with a sealing ring 7, a sealing ring 8, and a square cross-section sealing ring 9 to strengthen the seal. In this embodiment, there are continuous pressure fluctuations during the airtightness test. The sealing ring 7, the sealing ring 8, and the square cross-section sealing ring 9 strengthen the sealing effect between the adapter flange 1 and the gas control block 102, preventing high-pressure airflow during the airtightness test, ensuring the safety of the test personnel, and ensuring the accuracy of the test results.

[0074] The high-pressure oil supply port 24 is T-shaped. One end of the high-pressure oil supply port 24 is connected to the required piping system for testing through the pipe connector 12, and the other end is connected to the diaphragm accumulator 13. The sealing oil port 22 and the low-pressure oil supply port 25 are L-shaped. The other end of the sealing oil port 22 and the low-pressure oil supply port 25 are both connected to the ball valve assembly 5. The gas supply port 26 is T-shaped. One end of the gas supply port 26 is connected to the required piping system for testing through the pipe connector 12, and the other end is connected to the gas control block 102. In this embodiment, during the airtightness test, the L-shaped and T-shaped through holes inside the adapter flange 2 are regarded as the corresponding piping systems during the test.

[0075] In the installation fixtures and methods provided in the above embodiments of the present invention, the size of the dual-fuel diesel engine gas control block device varies depending on the size of different engine models, and the actual size of different configurations is known in the art.

[0076] The test method for the airtightness test of the gas control block of a marine dual-fuel diesel engine includes the following steps:

[0077] S1. First, the cylinder head completes the pressure test, and the gas control block completes the oil filling and cleaning of the internal pipeline. It is necessary to ensure that the adapter flange is aligned with the gas safety block, tighten the mounting bolts according to the instructions, then install the cylinder head on the test bench, install the adapter flange on the test bench, align the gas control block with the adapter flange and tighten it; it is necessary to ensure that all sealing surfaces are clean and free of scratches, and tighten the bolts to the required torque.

[0078] S2, then connect the pump pressure equipment and each test pipeline system to the adapter flange to complete the connection between the dual-fuel diesel engine gas function components and the adapter flange;

[0079] S3, then the pump pressure equipment stabilizes the low-pressure oil port to 5 bar through the connecting pipeline system. If the pressure drop is less than 0.75 bar every 5 minutes, the connection is considered qualified.

[0080] S4. Then, the pump pressurization equipment stabilizes the high-pressure oil port to 300 bar through the connecting pipeline system. If the pressure drop is less than 0.75 bar every 5 minutes, the connection is considered qualified.

[0081] S5, then the pump pressurization equipment stabilizes the pressure in the sealing oil hole to 320 bar through the connecting pipeline system. If the pressure drop is less than 0.75 bar every 5 minutes, the connection is considered qualified.

[0082] S6, then the pumping equipment gradually increases the pressure of the gas supply hole to 300 bar through the connecting pipeline system (every 50 bar, stabilize the pressure for 30 seconds to 1 minute, until 300 bar). After the pressure stabilizes, if the pressure drop is less than 0.75 bar every 5 minutes, the connection is qualified.

[0083] S7, and then conduct other subsequent tests according to the technical requirements;

[0084] S8. After all tests are completed, remove the adapter flange to complete other related installation work.

[0085] Example:

[0086] 1. Assembly of experimental fixtures

[0087] (1) Place the adapter flange (2) horizontally on the installation platform and install the following components in sequence:

[0088] Install the diaphragm accumulator (13) through the third threaded hole on the left end, and tighten it to a torque of 60±5 N·m.

[0089] Install the ball valve assembly (5) through the fourth threaded hole at the rear end, and tighten it to a torque of 45±5 N·m. Install the three-way plug (11) at the lower pipe interface and connect the reducer (3) and the silencer (4).

[0090] (2) Installation of sealing components:

[0091] Install the following sequentially on the upper end face of the adapter flange (2):

[0092] Square cross-section sealing ring (9) (specification Φ120×5mm)

[0093] Sealing ring (7) (Material: fluororubber)

[0094] O-ring (8) (Standard GB3452.1)

[0095] (3) Installation of hoisting components:

[0096] Install eye bolts (10) in the four second threaded holes, with a preload torque of 30 N·m.

[0097] 2. Test system connection

[0098] (1) Pipeline connection:

[0099] The T-shaped port A of the high-pressure oil supply hole (24) is connected to the high-pressure oil circuit of the pump pressure equipment (DN8 stainless steel pipe); the L-shaped port A of the low-pressure oil supply hole (25) is connected to the low-pressure oil circuit of the pump pressure equipment (DN6 stainless steel pipe); the L-shaped port A of the sealing oil hole (22) is connected to the sealing oil circuit of the pump pressure equipment (DN6 stainless steel pipe); the T-shaped port A of the fuel gas supply hole (26) is connected to the fuel gas supply system (DN10 stainless steel pipe)

[0100] (2) Connection of detection system:

[0101] A pressure sensor (measuring range: 0-350bar, accuracy: class 0.5) is installed at the fuel gas detection hole (21), and a pressure transmitter (accuracy: 0.1% FS) is installed at each oil circuit interface

[0102] 3. Operation Procedure of Air Tightness Test

[0103] (1) Pre-test inspection:

[0104] Check that the roughness of all sealing surfaces is ≤Ra1.6

[0105] Confirm that the bolt tightening torque meets the standard (recheck with a torque wrench)

[0106] Carry out a system air tightness pre-inspection (feed 5bar nitrogen and keep pressure for 3 minutes)

[0107] (2) Graded pressure test:

[0108] 1) Low-pressure oil test stage:

[0109] Boost pressure to 5bar at a rate of 1bar / s

[0110] Keep pressure for 5 minutes, and it is qualified if the pressure drop is ≤0.75bar

[0111] The test temperature is controlled at 20±5℃

[0112] 2) High-pressure oil test stage:

[0113] Boost pressure to 300bar at a rate of 5bar / s

[0114] Keep pressure for 5 minutes, and it is qualified if the pressure drop is ≤0.75bar

[0115] Monitor in real time that the pressure fluctuation of the membrane accumulator (13) is ≤±1%

[0116] 3) Sealing oil test stage:

[0117] Boost pressure to 320bar at a rate of 5bar / s

[0118] Keep pressure for 5 minutes, and it is qualified if the pressure drop is ≤0.75bar

[0119] The deformation of the square cross-section sealing ring (9) is monitored to be ≤0.1mm.

[0120] 4) Gas testing phase:

[0121] Increase the pressure gradually in 50-bar increments, stabilizing each increment for 30-60 seconds, until the final pressure reaches 300 bar. Hold this pressure for 5 minutes.

[0122] A pressure drop of ≤0.75 bar is considered acceptable.

[0123] Leakage rate detected using helium mass spectrometry ≤1×10⁻⁶ -6 mbar·L / s

[0124] (3) Exception handling:

[0125] The protection will be automatically triggered under the following circumstances:

[0126] Pressure fluctuations exceed the set value by ±5%.

[0127] Abnormal boost rate (>10 bar / s)

[0128] Temperature exceeding 50℃

[0129] Protective actions include:

[0130] 1) The ball valve assembly (5) cuts off the oil circuit within 0.3 seconds.

[0131] 2) Noise reduction device activated (noise level ≤ 85dB)

[0132] 3) The system automatically depressurizes (rate 20 bar / s).

[0133] Application Examples

[0134] Taking the MAN B&W 6S50ME-C9.5 dual-fuel engine as an example:

[0135] (1) Test parameters:

[0136] Gas control block model: GVU-50

[0137] Test medium: Nitrogen gas (99.99% purity)

[0138] Ambient temperature: 22℃

[0139] Relative humidity: 45%

[0140] (2) Test results:

[0141] 1) Low-pressure oil test:

[0142] Initial pressure: 5.02 bar

[0143] 5 minutes later: 4.89 bar

[0144] Pressure drop: 0.13 bar

[0145] 2) High-pressure oil test:

[0146] Initial pressure: 300.5 bar

[0147] 5 minutes later: 299.8 bar

[0148] Pressure drop: 0.7 bar

[0149] 3) Sealing oil test:

[0150] Initial pressure: 320.3 bar

[0151] 5 minutes later: 319.7 bar

[0152] Pressure drop: 0.6 bar

[0153] 4) Gas testing:

[0154] Final pressure: 300.2 bar

[0155] 5 minutes later: 299.6 bar

[0156] Pressure drop: 0.6 bar

[0157] Helium leak detection rate: 8×10 -7 mbar·L / s

[0158] (3) Comparison of working hours:

[0159] Traditional method: 6 hours and 15 minutes

[0160] The method of this invention: 1 hour and 40 minutes, efficiency increased by 73%.

[0161] Any matters not covered in the above embodiments of the present invention are well-known in the art.

[0162] 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. A test fixture for testing the airtightness of a gas control block in a marine dual-fuel diesel engine, characterized in that, include: The adapter flange (2) is provided with: Four first threaded holes evenly distributed on the upper end face are used for bolt connection with the gas control block (102); Four second threaded holes are evenly distributed on the outer circumference for installing eye bolts (10); The third threaded hole on the left end face is used to connect the diaphragm accumulator (13); The fourth threaded hole on the rear end face is used to connect the ball valve assembly (5); The lower end face is provided with a pipe interface for connecting a three-way valve (11); A gas detection hole (21) is provided on the side end face, and a removable screw plug (6) is provided on its outer port. The lower end face is also provided with a sealing oil hole (22), a drain oil hole (23), a high-pressure oil supply hole (24), a low-pressure oil supply hole (25), and a gas supply hole (26); the high-pressure oil supply hole (24) has a T-shaped structure, with its first port connected to the pump pressure equipment and its second port connected to the diaphragm accumulator (13); the sealing oil hole (22) and the low-pressure oil supply hole (25) have an L-shaped structure, with their first ports connected to the pump pressure equipment and their second ports connected to the ball valve assembly (5); the gas supply hole (26) has a T-shaped structure, with its first port connected to the pump pressure equipment and its second port connected to the gas control block (102); Also includes: The silencing device consists of a reducing connector (3), a muffler (4), and a three-way valve (11) connected in sequence; The sealing assembly includes a sealing ring (7), a sealing ring (8), and a square cross-section sealing ring (9) disposed between the adapter flange (2) and the gas control block (102).

2. The test fixture for the airtightness test of the gas control block of a marine dual-fuel diesel engine according to claim 1, characterized in that, The gas detection hole (21) and the gas supply hole (26) are connected through an internal channel to form a detection path.

3. The test fixture for the airtightness test of the gas control block of a marine dual-fuel diesel engine according to claim 1, characterized in that, The working pressure range of the high-pressure oil supply hole (24) is 0-320 bar, and the hole diameter tolerance is ±0.01 mm.

4. A method for airtightness testing using the test fixture described in any one of claims 1-3, characterized in that, Includes the following steps: S1. Installation preparation: Connect the gas control block (102) to the adapter flange (2) with bolts, and tighten to a torque of 80-100 N·m; check the installation status of the sealing ring (7), sealing ring (8) and square section sealing ring (9); S2. Pipeline connection: Connect the high-pressure oil circuit of the pump to the high-pressure oil supply hole (24); connect the low-pressure oil circuit of the pump to the low-pressure oil supply hole (25); connect the sealing oil circuit of the pump to the sealing oil hole (22); connect the gas pipeline of the pump to the gas supply hole (26); S3. Graded Pressure Test: a) Low-pressure oil test: Stabilize the pressure to 5±0.1 bar, hold the pressure for 5 minutes, and the pressure drop ≤0.75 bar is acceptable; b) High-pressure oil test: Stabilize the pressure to 300±1 bar, hold the pressure for 5 minutes, and the pressure drop ≤0.75 bar is acceptable; c) Sealing oil test: Stabilize the pressure to 320±1 bar, hold the pressure for 5 minutes, and the pressure drop ≤0.75 bar is acceptable; d) Gas test: Gradually increase the pressure to 300±1 bar in 50 bar increments, stabilize the pressure at each increment for 30-60 seconds, and finally hold the pressure for 5 minutes. The pressure drop ≤0.75 bar is acceptable.

5. The airtightness test method according to claim 4, characterized in that, In the gas test of step S3, when an abnormal pressure is detected, the following operations are performed automatically: the oil circuit is cut off within 0.5 seconds through the ball valve assembly (5); the silencer device consisting of the reducer (3), the silencer (4) and the three-way valve (11) is activated; and the audible and visual alarm signal is triggered.

6. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements automatic control of the airtightness testing method according to any one of claims 4-5, including: Real-time acquisition and processing of pressure data; Automatic sequence control of the testing process; Automatic identification and handling of abnormal situations; Automatic generation of test reports.

Images