Airtightness test device for fuel gas module of low-speed diesel engine for methanol dual-fuel ship

Abstract

The invention belongs to the technical field of diesel engine gas module gas tightness test devices, and particularly relates to a low-speed diesel engine gas module gas tightness test device for a methanol dual-fuel ship. The system comprises a pump pressure unit loop composed of three independent pneumatic hydraulic pumps, namely a low-pressure make-up oil booster pump, a low-pressure sealing oil booster pump and a high-pressure sealing oil booster pump, and a movable test board assembly device composed of a nitrogen boosting output unit, and the pump pressure unit loop unit takes compressed air as a power source. The pneumatic piston is pushed to do reciprocating motion, and the pneumatic piston drives the hydraulic plunger, so that the hydraulic oil is compressed and sent to the methanol gas module to be tested, thereby completing the airtightness test of valves such as a window valve and a block-off valve on the methanol gas module. The device is suitable for methanol dual-fuel main engines with various cylinder diameters, the labor intensity of workers is greatly reduced while the working efficiency is improved, and meanwhile the air tightness test quality is improved.

Description

Technical Field

[0001] This invention belongs to the technical field of diesel engine gas module air tightness testing device, specifically relating to a methanol dual-fuel marine low-speed diesel engine gas module air tightness testing device. Background Technology

[0002] After assembly, the gas module of a methanol dual-fuel marine low-speed diesel engine requires a rigorous airtightness test to ensure that its valves (such as window valves and blow-off valves) meet the sealing performance requirements under simulated operating conditions. Traditional testing methods rely on pressurization and pressure holding of a single medium (such as nitrogen or hydraulic oil), which has the following problems: low efficiency: multiple medium switching and equipment adjustments are required, resulting in a long test cycle; poor versatility: different cylinder diameter main engines require customized tooling, which is costly; high labor intensity: complex operation, requiring multiple people to cooperate, and manual pressure holding has low accuracy; functional limitations: it cannot simultaneously handle oil injection, gas injection, and multi-channel independent pressure control.

[0003] Existing marine low-speed diesel engine gas module air tightness testing devices, while some attempting to integrate hydraulic and pneumatic systems, generally lack modular design and are difficult to adapt to the needs of different engine models. Therefore, there is an urgent need for a universal air tightness testing device that integrates multiple independent pressure sources and supports rapid tooling switching to improve efficiency, reduce reliance on manual labor, and meet diverse testing requirements. Summary of the Invention

[0004] This invention addresses the problems of existing methanol dual-fuel marine low-speed diesel engine gas module air tightness testing devices, such as long testing cycles, low efficiency, poor versatility, high labor intensity, and high costs. It proposes a methanol dual-fuel marine low-speed diesel engine gas module air tightness testing device, comprising:

[0005] The pump pressure unit circuit includes four independent pneumatic hydraulic pumps: a low-pressure sealing oil pump, a high-pressure sealing oil pump, a control oil pump, and a low-pressure replenishment oil pump. Each pump uses compressed air as a power source and compresses hydraulic oil by driving a hydraulic plunger through a pneumatic piston.

[0006] Among them: the low-pressure sealing oil pump, the high-pressure sealing oil pump, the control oil pump and the low-pressure replenishment oil pump are respectively connected to the oil tank; the low-pressure sealing oil pump, the high-pressure sealing oil pump, the control oil pump and the low-pressure replenishment oil pump are respectively connected to the gas module through a universal connecting tool and a high-pressure hose assembly; the low-pressure replenishment oil pump, the low-pressure sealing oil pump, the high-pressure sealing oil pump and the control oil pump are respectively connected to the first gas source pressure reducing valve 181, the second gas source pressure reducing valve 182, the third gas source pressure reducing valve 183 and the fourth gas source pressure reducing valve 184 in sequence;

[0007] The low-pressure supply oil pump, low-pressure sealing oil pump, high-pressure sealing oil pump, and control oil pump are respectively connected to the first safety valve, the second safety valve, the third safety valve, and the fourth safety valve via a universal connecting tool and a high-pressure hose assembly.

[0008] The low-pressure sealing oil pump, the high-pressure sealing oil pump, and the control oil pump are respectively connected to a first accumulator, a second accumulator, and a third accumulator;

[0009] The nitrogen booster output unit includes a nitrogen inlet pressure reducing valve, a pressure gauge, and a digital pressure gauge connected in sequence, which are used to inject nitrogen into the gas module and regulate the pressure.

[0010] The mobile test stand assembly includes a compressed air source processor; the compressed air source processor is connected to a high-pressure sealing oil pump and a low-pressure replenishment oil pump respectively, and is used to purify and stabilize the air source to drive the high-pressure sealing oil pump and the low-pressure replenishment oil pump.

[0011] According to the above-described methanol dual-fuel marine low-speed diesel engine gas module air tightness test device, the pressure ratios of the low-pressure sealing oil pump, the high-pressure sealing oil pump, and the control oil pump are 6:1, 28:1, and 80:1, respectively, and the maximum output pressures are 42 bar, 196 bar, and 560 bar, respectively.

[0012] According to the above-described methanol dual-fuel marine low-speed diesel engine gas module air tightness test device, the working pressure of the nitrogen booster output unit is 13 bar, and the leakage detection threshold is ≤1.3 bar / min.

[0013] According to the above-described methanol dual-fuel marine low-speed diesel engine gas module air tightness test device, the first accumulator, the second accumulator, and the third accumulator are all airbag accumulators with a maximum pressure resistance of 560 bar, used for pressure stabilization and pressure compensation.

[0014] According to the above-described methanol dual-fuel marine low-speed diesel engine gas module air tightness test device, the high-pressure output and input interface model of the pump pressure unit circuit is 125.

[0015] According to the above-described methanol dual-fuel marine low-speed diesel engine gas module air tightness test device, the high-pressure hose assembly is covered with a transparent protective sleeve with a pressure resistance rating of ≥600 bar.

[0016] According to the methanol dual-fuel marine low-speed diesel engine gas module air tightness test device described above, the opening pressures of the first safety valve, the second safety valve, the third safety valve, and the fourth safety valve are 28 bar, 42 bar, and 196 bar for the hydraulic circuit and 13 bar for the nitrogen circuit, respectively.

[0017] According to the methanol dual-fuel marine low-speed diesel engine gas module air tightness test device described above, the first gas source pressure reducing valve, the second gas source pressure reducing valve, the third gas source pressure reducing valve, and the fourth gas source pressure reducing valve support continuous adjustment of input gas pressure from 0 to 7 bar and output oil pressure range from 5 to 560 bar.

[0018] According to the above-described methanol dual-fuel marine low-speed diesel engine gas module air tightness test device, the hydraulic oil is 32# anti-wear hydraulic oil with a working temperature range of -10℃ to 35℃.

[0019] According to the methanol dual-fuel marine low-speed diesel engine gas module air tightness test device described above, the test bench assembly is equipped with a nitrogen digital pressure gauge with a pressure error ≤ Class 1.0.

[0020] The beneficial effects of the present invention are as follows:

[0021] 1. Multi-stage pressure precision control improves detection accuracy and reliability. Existing airtightness tests use a single oil or air pump, which cannot simulate the complex operating conditions of multiple valves in a methanol module (e.g., the window valve requires 300 bar oil pressure, and the nitrogen system requires 13 bar). Pressure fluctuations during the holding phase are >5%, easily leading to misjudgments of leaks. This device features four independent gas-liquid booster pumps: a low-pressure supply oil pump provides 5 bar of supply oil, a low-pressure sealing oil pump provides 16 bar of low-pressure sealing oil, a high-pressure sealing oil pump provides 40 bar of high-pressure sealing oil, and a control oil pump provides 300 bar of control oil; the first, second, and third accumulators stabilize the pressure and absorb pressure pulsations from each pump. Precise matching of valve operating conditions across multiple pressure levels (e.g., the window valve requires 300 bar oil pressure for actuation) ensures pressure fluctuations during the holding phase are ≤0.5%. Actual test data shows that the false alarm rate caused by unstable pressure has been reduced from 18% to 0%, and the leak detection accuracy has reached ±0.1 bar (pressure gauge Class 1.0), which fully meets the stringent standard of ≤1.3 bar leakage of 13 bar nitrogen in 1 minute.

[0022] 2. Integrated gas-liquid dual-medium testing reduces process and equipment investment, improving efficiency. Existing technology requires separate hydraulic stations to test the oil circuit and nitrogen cylinders to test the gas circuit, with a single main unit switching time of ≥1.5 hours and requiring 4 operators. This device features an integrated gas-liquid dual-circuit structure: a pump pressure unit circuit (four hydraulic circuits) + a nitrogen booster output unit; a quick-connect system: 9×125 female connectors + high-pressure hoses. Seamless switching between oil and gas testing reduces the testing time of a single main unit. It can serve 4 main units simultaneously, reducing the number of operators to 2, significantly improving equipment utilization. It also saves on hydraulic station / air pump costs.

[0023] 3. The pneumatic hydraulic pump offers significant energy savings, excellent low-temperature adaptability, and reduced energy consumption. Existing electric hydraulic pumps face starting difficulties at -10℃, increasing energy consumption by 40% and requiring a preheating device. This device utilizes a compressed air power supply processor driven by 7 bar compressed air; it also employs a low-temperature adaptable structure: stainless steel fittings and low-temperature hydraulic oil. The compressed air power supply processor can start directly at -10℃ without preheating, reducing energy consumption per test. Compressed air power also eliminates the risk of motor burnout, reducing maintenance costs.

[0024] 5. Modular tooling enables full coverage of the entire range of main engines, saving resources. Existing technology requires customized tooling for main engines with different cylinder diameters, resulting in large tooling inventory and time-consuming changeovers. This device offers interchangeable connecting tooling: a 125mm female connector + G1 / 4 transition connector: 12 sets of quick-connect interfaces to adapt to different hydraulic circuit layouts. Simply changing the tooling covers the entire MAN B&W main engine series. Tooling inventory is reduced, storage space is saved, and annual tooling manufacturing costs are lowered. The universal structure improves the utilization rate of the device.

[0025] 5. Nitrogen closed-loop testing eliminates water pollution. Existing technology uses hydrostatic testing, consuming 3 tons of water per unit, and the wastewater contains oil and requires special treatment. This device features a closed-loop nitrogen booster output unit: a nitrogen inlet pressure reducing valve precisely controls nitrogen flow to 13 bar; all oil is recovered, and the return oil hose has a quick-connect fitting to the gas module tooling. This completely replaces hydrostatic testing, reducing waste discharge. The nitrogen medium is pollution-free and recyclable. The oil recovery rate is >99%, reducing oil stains at the work site.

[0026] Applications show that this device reduces the time for a single test by 40%, reduces the number of operators to 2, increases the leak detection accuracy to 99.5%, significantly saves costs, and significantly improves production efficiency and the quality of airtightness testing. Attached Figure Description

[0027] Figure 1 This is a simplified structural diagram of the gas tightness test device for the gas module of a methanol dual-fuel marine low-speed diesel engine according to the present invention.

[0028] Figure 2 This is a schematic diagram of the gas module of a methanol dual-fuel marine low-speed diesel engine.

[0029] In the diagram: 1-Low-pressure supply oil pump, 2-Low-pressure sealing oil pump, 3-High-pressure sealing oil pump, 4-Control oil pump, 5-Compressed air source processor, 6-Nitrogen inlet pressure reducing valve, 7-Nitrogen output device, 10-First safety valve, 11-Second safety valve, 12-Third safety valve, 13-Fourth safety valve, 14-Pressure gauge, First air source pressure reducing valve 181, Second air source pressure reducing valve 182, Third air source pressure reducing valve 183, Fourth air source pressure reducing valve 184, 21-Digital pressure gauge, 28-First accumulator, 38-Second accumulator, 48-Third accumulator, 100-Nitrogen cylinder, 200-Oil tank, 300-Gas module, 800-Window valve, 817-817 valve, 818-818 valve, 819-819 valve, 892-892 valve, 900-Blow-off valve. Detailed Implementation

[0030] Preferred Implementation

[0031] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0032] like Figure 1 and Figure 2 As shown: The methanol dual-fuel marine low-speed diesel engine gas module air tightness testing device of this embodiment includes:

[0033] The pump pressure unit circuit consists of four independent pneumatic hydraulic pumps: low-pressure sealing oil pump 2, high-pressure sealing oil pump 3, control oil pump 4, and low-pressure replenishment oil pump 1. Each pump uses compressed air as a power source and compresses hydraulic oil by driving the hydraulic plunger through a pneumatic piston.

[0034] The low-pressure sealing oil pump 2, the high-pressure sealing oil pump 3, the control oil pump 4 and the low-pressure replenishment oil pump 1 are respectively connected to the oil tank 200; the low-pressure sealing oil pump 2, the high-pressure sealing oil pump 3, the control oil pump 4 and the low-pressure replenishment oil pump 1 are respectively connected to the gas module 300 through a universal connecting tool and a high-pressure hose assembly.

[0035] Low-pressure supply oil pump 1, low-pressure sealing oil pump 2, high-pressure sealing oil pump 3, and control oil pump 4 are respectively connected to the first safety valve 10, the second safety valve 11, the third safety valve 12, and the fourth safety valve 13 through universal connecting tooling and high-pressure hose assembly.

[0036] The low-pressure sealing oil pump 2, the high-pressure sealing oil pump 3, and the control oil pump 4 are respectively connected to the first accumulator 28, the second accumulator 38, and the third accumulator 48;

[0037] The nitrogen booster output unit includes a pressure reducing valve 6 and a digital pressure gauge 21, which are used to inject nitrogen into the gas module 300 and regulate the pressure.

[0038] The mobile test stand assembly includes a compressed air source processor 5; the compressed air source processor 5 is connected to the high-pressure sealing oil pump 3 and the low-pressure replenishment oil pump 1 respectively.

[0039] The gas module 300 is connected to a nitrogen output device 7; the nitrogen output device 7 is connected to a nitrogen inlet pressure reducing valve 6 and a pressure gauge 14.

[0040] The pressure boosting ratios of the low-pressure sealing oil pump 2, the high-pressure sealing oil pump 3, and the control oil pump 4 are 6:1, 28:1, and 80:1, respectively, and their maximum output pressures are 42 bar, 196 bar, and 560 bar, respectively.

[0041] The working pressure of the nitrogen booster output unit is 13 bar, and the leakage detection threshold is ≤1.3 bar / min.

[0042] The first accumulator 28, the second accumulator 38, and the third accumulator 48 are used for voltage stabilization and pressure compensation.

[0043] The universal connection fixture includes a quick-connect adapter: model G1 / 4 transition connector, and a modular frame made of stainless steel.

[0044] High-pressure hose assembly, 3 m x 10 pieces, covered with a transparent protective sleeve, pressure rating ≥600 bar.

[0045] The opening pressures of the first safety valve 10, the second safety valve 11, the third safety valve 12, and the fourth safety valve 13 are 28 bar, 42 bar, and 196 bar for the hydraulic circuit and 13 bar for the nitrogen circuit, respectively.

[0046] The first air source pressure reducing valve 181, the second air source pressure reducing valve 182, the third air source pressure reducing valve 183, and the fourth air source pressure reducing valve 184 support continuous adjustment of input air pressure from 0 to 7 bar and output oil pressure range from 5 to 560 bar.

[0047] The hydraulic oil is 32# anti-wear hydraulic oil, and the working temperature range is -10℃ to 35℃.

[0048] The test bench assembly is equipped with a nitrogen digital pressure gauge 21, with a pressure error ≤ Class 1.0.

[0049] The system consists of four independent pressure sources: a low-pressure replenishment oil booster pump 1, a low-pressure sealing oil booster pump 2, a high-pressure sealing oil booster pump 3, and an oil production booster pump 4. The nitrogen section comprises two independent pressure sources with reduced pressure outputs that can be used independently.

[0050] The first safety valve 10, the second safety valve 11, the third safety valve 12, and the fourth safety valve 13 are used for the highest pressure in the hydraulic circuit and the nitrogen system;

[0051] The first throttle valve 15 and the second throttle valve 20 are throttle valves, and their function is to shut off or relieve pressure.

[0052] The first air source pressure reducing valve 181, the second air source pressure reducing valve 182, the third air source pressure reducing valve 183, and the fourth air source pressure reducing valve 184 are used to adjust the input air pressure of the pneumatic pump, thereby achieving the required output oil pressure.

[0053] The low-pressure sealing oil booster pump 2, the high-pressure sealing oil booster pump 3, and the oil booster pump 4 are all equipped with accumulators, which have the functions of stabilizing pressure and compensating.

[0054] Nitrogen inlet pressure reducing valve 6 is used to regulate the nitrogen outlet pressure;

[0055] The compressed air source processor 5 has two independent pneumatic booster pumps, connected to a first air source pressure reducing valve 181, a second air source pressure reducing valve 182, a third air source pressure reducing valve 183, and a fourth air source pressure reducing valve 184 with adjustable outlet pressure, to meet different hydraulic pressure output conditions. It can automatically stop when the set pressure is reached and automatically replenish pressure after pressure loss.

[0056] This device uses hydraulic oil type 32#. A nitrogen output is provided with a digital nitrogen pressure gauge (21) for easy airtightness testing; a nitrogen charging port is also included for charging the accumulator with nitrogen.

[0057] Operating temperature: -10~35℃;

[0058] Compressed air source interface thread: G1 / 2;

[0059] Nitrogen gas source interface thread: G1 / 4;

[0060] Pressure output interface thread: G1 / 4;

[0061] The frame and fittings of this device are all made of stainless steel.

[0062] This device has 9 high-pressure output / input interfaces: 125mm female connectors and 1 low-pressure return port. It is equipped with 10 high-pressure hose assemblies, each 3m long. Each high-pressure hose has one male and one female quick-connect coupling at both ends. The high-pressure hose assembly has a transparent protective sleeve. There are 12 tooling inlet / outlet 125mm male quick-connect couplings + G1 / 4 transition couplings.

[0063] The return oil pipe of this device is matched with the tooling and the return oil hose is in the form of a quick connector. There is one return oil hose with a length of 4 meters. Implementation

[0064] The implementation of this embodiment is further described below with reference to the accompanying drawings. This embodiment uses the gas module of the 7S60MEC10.5 host as an example to conduct an airtightness test:

[0065] The following are the operating procedures for the airtightness test of the first to fifth cylinders of the gas module 300:

[0066] 1. After assembling the universal connection tooling on the gas module 300, connect the corresponding high-pressure hose. Start the low-pressure replenishment oil booster pump 1, provide 5 bar lubricating oil pressure and maintain pressure; start the low-pressure sealing oil booster pump 2, provide 16 bar lubricating oil pressure and maintain pressure; start the high-pressure sealing oil booster pump 3, provide 40 bar lubricating oil pressure and maintain pressure; start the control oil booster pump 4, provide 300 bar lubricating oil pressure and maintain pressure; provide 13 bar of nitrogen, close the window valve, and observe whether the pressure drops. If the pressure drops to ≤1.3 bar / min, it is acceptable, indicating that the contact between the window valve and the adapter block is good and there is no leakage, which also indicates that the sealing performance of the window valve body is relatively good.

[0067] 2. Close the blow-off valve, open the window valve, keep the low-pressure replenishment oil, low-pressure sealing oil, high-pressure sealing oil, and control oil pressures constant, supply 13 bar of nitrogen, and observe whether the pressure on pressure gauge 14 changes.

[0068] If the pressure drop is ≤1.3 bar / min, it is considered acceptable, indicating that the contact between the blow-off valve and the adapter block is good and there is no leakage. It also indicates that the sealing performance of the blow-off valve body is relatively good.

[0069] The procedure for the airtightness test of the sixth cylinder of the gas module is as follows:

[0070] 1. After assembling the tooling on the gas module 300, connect the corresponding hoses. Start the low-pressure replenishment oil booster pump 1, provide 5 bar lubricating oil pressure and maintain pressure; start the low-pressure sealing oil booster pump 2, provide 16 bar lubricating oil pressure and maintain pressure; start the high-pressure sealing oil booster pump 3, provide 40 bar lubricating oil pressure and maintain pressure; start the control oil booster pump 4, provide 300 bar lubricating oil pressure and maintain pressure; close the window valve, close the 892 valve, open the blow-off valve, open the nitrogen release valve, provide 13 bar of nitrogen, and observe whether the pressure on pressure gauge 14 drops. If the pressure drop is ≤1.3 bar / min, it is qualified, indicating that the sealing of the window valve and the 892 valve is qualified.

[0071] 2. Close the blow-off valve, open the window valve, close the 892 valve, open the nitrogen release valve, keep the low-pressure replenishment oil, low-pressure sealing oil, high-pressure sealing oil, and control oil pressures constant, supply 13 bar of nitrogen, and observe whether the pressure gauge pressure changes. If the pressure drops to ≤1.3 bar / min, it is qualified, indicating that the blow-off valve's sealing performance is qualified.

[0072] 3. Open the window valve, open the blow-off valve, close valve 892, close the nitrogen release valve, keep the low-pressure supply oil, low-pressure sealing oil, high-pressure sealing oil, and control oil pressures constant, supply 13 bar of nitrogen, and observe whether the pressure gauge pressure changes. If the pressure drops to ≤1.3 bar / min, it is qualified, indicating that valve 892's sealing performance is qualified.

[0073] 4. Close valve 817, close valve 818, open valve 819, close valve 892. Keep the pressure of low-pressure replenishment oil, low-pressure sealing oil, high-pressure sealing oil, and control oil constant. Provide 9 bar of nitrogen and observe whether the pressure on pressure gauge 14 changes. If the pressure does not change, it is qualified, indicating that valve 817 has good sealing performance.

[0074] 5. Open valve 817, close valve 818, close valve 819, and close valve 892. Keep the low-pressure replenishment oil, low-pressure sealing oil, high-pressure sealing oil, and control oil pressures constant. Supply 9 bar of nitrogen and observe whether the pressure on pressure gauge 14 changes. If the pressure does not change, it is acceptable; or if the pressure drop is ≤1.3 bar / min, it is acceptable. This indicates that valves 818 and 819 are sealing well.

[0075] The specific parameters of the pump of the present invention are shown in Table 1.

[0076] Table 1. Parameter table of the pump of the present invention

[0077]

[0078] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A test apparatus for the air tightness of the gas module of a methanol dual-fuel marine low-speed diesel engine, characterized in that, include: The pump pressure unit circuit includes four independent pneumatic hydraulic pumps: a low-pressure sealing oil pump (2), a high-pressure sealing oil pump (3), a control oil pump (4), and a low-pressure replenishment oil pump (1). Each pump uses compressed air as its power source and drives the hydraulic plunger to compress hydraulic oil through a pneumatic piston. Among them: the low-pressure sealing oil pump (2), the high-pressure sealing oil pump (3), the control oil pump (4) and the low-pressure replenishment oil pump (1) are respectively connected to the oil tank (200); the low-pressure sealing oil pump (2), the high-pressure sealing oil pump (3), the control oil pump (4) and the low-pressure replenishment oil pump (1) are respectively connected to the gas module (300) through a universal connecting tool and a high-pressure hose assembly; the low-pressure replenishment oil pump (1), the low-pressure sealing oil pump (2), the high-pressure sealing oil pump (3) and the control oil pump (4) are respectively connected to the first gas source pressure reducing valve 181, the second gas source pressure reducing valve 182, the third gas source pressure reducing valve 183 and the fourth gas source pressure reducing valve 184 in sequence; The low-pressure supply oil pump (1), low-pressure sealing oil pump (2), high-pressure sealing oil pump (3), and control oil pump (4) are respectively connected to the first safety valve (10), the second safety valve (11), the third safety valve (12), and the fourth safety valve (13) through a universal connecting tool and a high-pressure hose assembly. The low-pressure sealing oil pump (2), the high-pressure sealing oil pump (3), and the control oil pump (4) are respectively connected to the first accumulator (28), the second accumulator (38), and the third accumulator (48). The nitrogen booster output unit includes a nitrogen inlet pressure reducing valve (6), a pressure gauge (14), and a digital pressure gauge (21) connected in sequence, which are used to inject nitrogen into the gas module (300) and regulate the pressure. The mobile test stand assembly includes a compressed air source processor (5); the compressed air source processor (5) is connected to the high-pressure sealing oil pump (3) and the low-pressure replenishment oil pump (1) respectively, and is used to purify and stabilize the air source and drive the high-pressure sealing oil pump (3) and the low-pressure replenishment oil pump (1).

2. The gas tightness testing device for the gas module of a methanol dual-fuel marine low-speed diesel engine according to claim 1, characterized in that, The pressure ratios of the low-pressure sealing oil pump (2), the high-pressure sealing oil pump (3), and the control oil pump (4) are 6:1, 28:1, and 80:1, respectively, and the maximum output pressures are 42 bar, 196 bar, and 560 bar, respectively.

3. The gas tightness testing device for the gas module of a methanol dual-fuel marine low-speed diesel engine according to claim 2, characterized in that, The working pressure of the nitrogen booster output unit is 13 bar, and the leakage detection threshold is ≤1.3 bar / min.

4. The gas tightness testing device for the gas module of a methanol dual-fuel marine low-speed diesel engine according to claim 3, characterized in that, The first accumulator (28), the second accumulator (38), and the third accumulator (48) are all pneumatic accumulators with a maximum pressure resistance of 560 bar, used for pressure stabilization and pressure compensation.

5. The gas tightness testing device for the gas module of a methanol dual-fuel marine low-speed diesel engine according to claim 4, characterized in that, The high-pressure output and input interface of the pump pressure unit circuit is model 125.

6. The gas tightness testing device for the gas module of a methanol dual-fuel marine low-speed diesel engine according to claim 5, characterized in that, The high-pressure hose assembly is covered with a transparent protective sleeve with a pressure rating of ≥600 bar.

7. The gas tightness testing device for the gas module of a methanol dual-fuel marine low-speed diesel engine according to claim 6, characterized in that, The opening pressures of the first safety valve (10), the second safety valve (11), the third safety valve (12), and the fourth safety valve (13) are 28 bar, 42 bar, and 196 bar for the hydraulic circuit and 13 bar for the nitrogen circuit, respectively.

8. The gas tightness testing device for the gas module of a methanol dual-fuel marine low-speed diesel engine according to claim 7, characterized in that, The first air source pressure reducing valve (181), the second air source pressure reducing valve (182), the third air source pressure reducing valve (183), and the fourth air source pressure reducing valve (184) support continuous adjustment of input air pressure from 0 to 7 bar and output oil pressure range from 5 to 560 bar.

9. The gas tightness testing device for the gas module of a methanol dual-fuel marine low-speed diesel engine according to claim 8, characterized in that, The hydraulic oil is 32# anti-wear hydraulic oil, with an operating temperature range of -10℃ to 35℃.

10. The gas tightness testing device for the gas module of a methanol dual-fuel marine low-speed diesel engine according to claim 9, characterized in that, The test bench assembly is equipped with a nitrogen digital pressure gauge (21) with a pressure error ≤ Class 1.0.

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