Self-adaptive lap joint flange for outer pipe of fuel gas double-wall pipe of marine low-speed diesel engine

Abstract

The invention discloses a self-adaptive lap joint flange for an outer pipe of a fuel gas double-wall pipe of a marine low-speed diesel engine, which is movably connected to the end part of the outer pipe of the double-wall pipe and comprises an inner hole, the inner hole is a stepped hole, a gap is formed between the inner hole and a flange of the inner pipe of the double-wall pipe, and the inner hole comprises a large hole and a small hole which are coaxially connected; the inner wall of the small hole is a sliding sealing face, and a sealing ring is arranged between the sliding sealing face and the periphery of the outer pipe. After the inner pipes are assembled in a paired mode, if centering deviation of the outer pipes is caused by machining errors, radial stress generated by deformation of the outer pipes can be eliminated by adjusting gaps between the lap joint flanges and the outer pipes, and the lap joint flanges can axially slide along the outer pipes; the axial stress of the flange on the pipeline can be reduced or eliminated through sliding of the lap joint flange, so that the pipeline is prevented from being broken. The reliability, stability and safety of gas pipeline connection are improved.

Description

Technical Field

[0001] The invention relates to a gas pipeline of a marine diesel engine, in particular to an adaptive slip-on flange of an outer pipe of a double-walled gas pipe of a marine low-speed diesel engine, belonging to the technical field of internal combustion engines. Background Art

[0002] In today's marine low-speed diesel engine market, technological innovation continues to surge, with various advanced technologies constantly being introduced, leading the industry's development and transformation. Among them, low-pressure dual-fuel engines, with their unique advantages, are gradually emerging in the market, and their market share has shown a positive trend of steady annual growth. These engines not only flexibly utilize traditional fuels but also efficiently utilize clean energy sources such as natural gas. While meeting ship power requirements, they significantly reduce pollutant emissions, meeting the global shipping industry's urgent need for environmental protection and sustainable development.

[0003] Low-pressure dual-fuel main engines utilize double-walled pipes for their gas transmission systems. This double-walled pipe structure offers significant advantages in terms of enhanced safety and reduced risk of gas leaks. However, in actual engineering applications, the connections between the double-walled pipes face numerous pressing challenges. Due to the inevitable errors in the manufacturing process, deviations can easily occur during pipe alignment and connection. These deviations can cause additional stress on the outer pipes after connection, significantly reducing the reliability of the connection, increasing the potential risk of gas leaks, and posing a threat to the safe operation of the vessel.

[0004] Furthermore, once gas pipelines are installed and put into operation, their operating environment is complex and dynamic. Ships experience varying climatic conditions and operating conditions during navigation, leading to frequent fluctuations in environmental parameters such as temperature and pressure. In these conditions, gas pipelines are susceptible to significant deformation due to thermal expansion and contraction, which generates internal stress. If this stress accumulates over time and is not effectively relieved, the likelihood of a gas pipeline rupture increases significantly. Once a gas pipeline ruptures, it not only affects the ship's power supply but can also cause serious safety incidents.

[0005] At the same time, during the operation of the system, the negative pressure fan needs to extract air from the outer pipe of the double-wall pipe to maintain the normal pressure balance and safe operation of the system. However, in this process, the pipe joints are prone to air leakage due to the influence of various factors such as structure and stress. This will not only cause energy waste, but may also lead to local accumulation of combustible gas, creating a potential explosion hazard, posing a great threat to the safety of life and property of the ship and the personnel on board.

[0006] In summary, these problems currently faced by the double-wall pipe connection of the low-pressure dual-fuel host gas pipeline have seriously restricted the further promotion and application of dual-fuel host technology. An innovative solution is urgently needed to effectively address these challenges and improve the reliability, stability and safety of the gas pipeline connection. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to overcome the shortcomings of conventional double-wall pipe connections and provide an adaptive slip-on flange for the outer pipe of a double-wall gas pipe for a marine low-speed diesel engine, thereby eliminating the additional stress caused by processing errors, reducing the deformation stress of the gas pipe caused by hot and cold changes, preventing leakage of gas in the pipe at the double-wall pipe connection, and forming a flammable and explosive area, thereby achieving the purpose of improving the reliability, stability and safety of the gas pipeline connection.

[0008] Based on the above objectives, the present invention solves the technical problems as follows:

[0009] An adaptive slip-on flange for the outer tube of a double-walled gas tube for a marine low-speed diesel engine, the double-walled tube comprising a coaxial inner tube and outer tube, characterized in that the adaptive slip-on flange is movably connected to the end of the outer tube and comprises an inner hole, with a gap between the inner hole and the flange of the inner tube. When the inner tubes are paired and assembled, if the outer tube deviates from the centering due to machining errors, the radial stress generated by the deformation of the outer tube can be eliminated by adjusting the gap. The adaptive slip-on flange can slide axially along the outer tube. When the outer tube is deformed due to heating or cooling, the sliding of the adaptive slip-on flange can reduce or eliminate the axial stress generated by the adaptive slip-on flange on the pipeline, thereby preventing the pipeline from breaking.

[0010] Furthermore, the inner hole is a stepped hole, including a large hole and a small hole coaxially connected, the flange of the inner tube is accommodated in the large hole and there is an adjustable gap between the outer periphery and the inner wall of the large hole, the orifice of the small hole is provided with an annular boss, the inner wall is a sliding sealing surface, and a sealing ring is provided between the sliding sealing surface and the outer periphery of the outer tube to prevent gas leakage when the outer tube is evacuated, so as to ensure the safety of the area outside the double-walled tube.

[0011] Furthermore, a boss is provided at the end of the outer tube, a sealing groove is provided on the outer periphery of the boss, the sealing ring is arranged in the sealing groove and the outer periphery is in close contact with the sliding sealing surface of the small hole to seal the inner cavity of the outer tube to prevent air leakage.

[0012] Furthermore, the inner side of the annular boss of the small hole is close to the side surface of the boss of the outer tube.

[0013] Furthermore, there is a clearance fit between the sliding sealing surface and the outer periphery of the boss.

[0014] Compared with the existing rigid outer tube flange, the adaptive slip-on flange of the present invention can prevent radial stress caused by pipeline alignment deviation due to processing errors by adjusting the gap between the outer tube and the inner tube; when the pipeline is deformed due to heat and cold, the adaptive slip-on flange reduces or eliminates the axial stress of the flange on the pipeline by sliding between the outer tube, thereby preventing the pipeline from breaking; at the same time, the sealing ring between the outer periphery of the outer tube and the adaptive slip-on flange can prevent gas from leaking from the interface, forming a flammable and explosive area, thereby ensuring the safety of the area outside the double-wall pipe.

[0015] In summary, the present invention improves the reliability, stability and safety of gas pipeline connections. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is an assembly connection schematic diagram of the present invention.

[0017] Figure 2 It is a structural cross-sectional view of the present invention.

[0018] In the figure, 1 is a bolt hole, 2 is a large hole, 3 is a small hole, 31 is a sliding sealing surface, 4 is an annular boss, 101 is a slip-on flange, 102 is an outer tube, 103 is an inner tube flange, and 104 is a sealing ring. DETAILED DESCRIPTION

[0019] The present invention will be further described below through specific embodiments in conjunction with the accompanying drawings. These embodiments are only used to illustrate the present invention and are not intended to limit the scope of protection of the present invention.

[0020] The invention is used for connecting the outer pipe of a double-walled pipe for a low-speed marine diesel engine fuel gas. The double-walled pipe comprises a coaxial inner pipe and an outer pipe. The end of the outer pipe is provided with a boss, and the outer periphery of the boss is provided with a sealing groove.

[0021] like Figure 1 and Figure 2 As shown, the adaptive slip-on flange 101 is movably connected to the end of the outer tube 102 of the double-walled tube and can slide axially along the outer tube 102 .

[0022] The slip-on flange 101 includes an inner bore and bolt holes 1. The inner bore is a stepped hole, comprising a large hole 2 and a small hole 3 coaxially connected. The inner tube flange 103 is accommodated in the large hole 2, with an adjustable gap between its outer periphery and the inner wall of the large hole 2. The opening of the small hole 3 is provided with an annular boss 4, the inner wall of which forms a sliding sealing surface 31. A sealing ring 104 is positioned between this sliding sealing surface 31 and the outer periphery of the outer tube 102. The end of the outer tube 102 is provided with a boss, the outer periphery of which is provided with a sealing groove. The sealing ring 104 is positioned within this sealing groove, with its outer periphery in close contact with the sliding sealing surface 31 of the small hole 3, sealing the inner cavity of the outer tube 102 and preventing air leakage. The sliding sealing surface 31 and the outer periphery of the boss of the outer tube 102 are clearance-fitted, with the inner side of the annular boss 4 of the small hole 3 abutting against the side of the boss.

[0023] When a negative pressure blower is used to extract gas from the outer tube 102, the sealing ring 104 can prevent the gas in the outer tube 102 of the double-walled gas tube from leaking through the gap between the adaptive slip-on flange 101 and the outer tube 102, thereby turning the area outside the tube into a safe area.

[0024] After the inner tube flange 103 is assembled with the mating flange, if there is a deviation in the alignment of the outer tube 102 , the gap between the outer tube 102 and the inner tube can be adjusted to eliminate the radial stress caused by the deformation of the outer tube 102 .

[0025] When the outer tube 102 is deformed due to thermal changes, the slip-on flange 101 can slide against the outer tube 102 , thereby reducing or eliminating the axial stress of the flange on the pipeline and preventing the pipeline from breaking.

[0026] The above embodiments are not intended to limit the scope of the present invention. The scope of protection claimed by the present invention is not limited to the above embodiments, but should also include other obvious changes and alternatives to the present invention. All equivalent changes and modifications made based on the contents of the present invention fall within the scope of the present invention.

Claims

1. An adaptive slip-on flange for a double-walled gas pipe outer tube for a low-speed marine diesel engine, the double-walled pipe comprising a coaxial inner tube and an outer tube, characterized in that: The adaptive slip-on flange is movably connected to the end of the outer tube and includes an inner hole. There is a gap between the inner hole and the flange of the inner tube. When the inner tubes are paired and assembled, if the outer tube deviates from the centering due to processing errors, the radial stress caused by the deformation of the outer tube can be eliminated by adjusting the gap. The adaptive slip-on flange can slide axially along the outer tube. When the outer tube is deformed due to heating or cooling, the sliding of the adaptive slip-on flange can reduce or eliminate the axial stress generated by the adaptive slip-on flange on the pipeline to prevent the pipeline from breaking.

2. The adaptive slip-on flange for the outer tube of a double-walled gas tube for a low-speed marine diesel engine according to claim 1, characterized in that: The inner hole is a stepped hole, including a large hole and a small hole coaxially connected. The flange of the inner tube is accommodated in the large hole and there is an adjustable gap between the outer periphery and the inner wall of the large hole. The orifice of the small hole is provided with an annular boss, and the inner wall is a sliding sealing surface. A sealing ring is provided between the sliding sealing surface and the outer periphery of the outer tube to prevent gas leakage when the outer tube is evacuated, so as to ensure the safety of the area outside the double-walled tube.

3. The adaptive slip-on flange for the outer tube of a double-walled gas tube for a low-speed marine diesel engine according to claim 2, characterized in that: The end of the outer tube is provided with a boss, the outer periphery of which is provided with a sealing groove. The sealing ring is arranged in the sealing groove and its outer periphery is in close contact with the sliding sealing surface of the small hole to seal the inner cavity of the outer tube to prevent air leakage.

4. The adaptive slip-on flange for the outer tube of a double-walled gas tube for a low-speed marine diesel engine according to claim 3, characterized in that: The inner side of the annular boss of the small hole is close to the side surface of the boss of the outer tube.

5. The adaptive slip-on flange for the outer tube of a double-walled gas tube for a low-speed marine diesel engine according to claim 3, characterized in that: There is a clearance fit between the sliding sealing surface and the outer periphery of the boss.

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