Anti-leakage safety system for annular area of double-wall pipe of return pipeline of methanol dual-fuel generator

Abstract

The invention discloses a leakage-proof safety system for a double-wall pipe annular area of a return pipeline of a methanol dual-fuel generator. The leakage-proof safety system comprises a pressure reducing valve, a manual stop valve, a release module, a stop check valve, the methanol dual-fuel generator, a stop check valve, a release valve, a safety valve, a manual stop valve, a balance valve and a terminal release valve. The pressure reducing valve is used for reducing the pressure of 13bar nitrogen to 2bar nitrogen, so that the 2bar nitrogen fills the annular area, and the release module is used for connecting the annular area with the inner pipe of the double-wall pipe. The manual stop valve is used for manually purging methanol leaked from the annular area, and the terminal release valve is used for introducing methanol liquid remaining in the annular area into the portable release tank. The problem of leakage of the double-wall pipe annular area of the methanol generator in the safe area can be rapidly solved, methanol in the annular area is cleared away through a sealing measure, methanol in the annular area is rapidly cleared away, and the device has the advantages of being simple in design, convenient to operate, safe and anti-explosion.

Description

Technical Field

[0001] This invention relates to a methanol dual-fuel generator, and more specifically, to a safe arrangement for a methanol dual-fuel generator. Background Technology

[0002] During ship operation, under normal generator operating conditions, there is no methanol leakage in the annular area of ​​the double-walled pipe. However, if methanol leakage occurs during the design process, it is a problem that needs to be solved. That is, it is necessary to address the safety hazard of methanol leakage in the annular area of ​​the safety zone, so that it can meet the specifications and the hazard can be eliminated quickly.

[0003] There is no requirement in the existing technology to eliminate such potential hazards, nor is there a solution to this problem. Existing nitrogen generators are only used for purging during initial use or cleaning phases, but do not address the handling of leaks, and there are no requirements or designs for such leak handling in this technical field.

[0004] According to the specifications, in the equipment layout plan for the methanol project, the methanol daily use cabinet for supplying methanol is arranged above the methanol dual-fuel generator. Summary of the Invention

[0005] This invention addresses the problem of methanol leakage in the annular zone of a double-walled methanol pipeline in hazardous areas. In particular, it designs a solution for the annular zone where methanol leaks into the return pipeline, enabling rapid elimination of potential hazards and ensuring navigational safety.

[0006] To achieve the above objectives, the present invention provides a methanol dual-fuel generator return pipeline double-walled annular zone leak prevention safety system, wherein the methanol dual-fuel generator is provided with a return pipeline in the form of a double-walled pipe; the inner pipe of the return pipeline is used to return methanol; the outer pipe of the return pipeline is connected to a nitrogen supply end, thereby filling it with nitrogen. The return pipeline is connected to the nitrogen supply end at the low point by a first manual shut-off valve C2. The return pipeline is connected to the nitrogen outlet of the methanol release cabinet at the high point via a second manual shut-off valve C9.

[0007] In a preferred embodiment, a liquid level detection switch or a methanol detection sensor is also installed at the lowest position of the outer pipe of the double-walled return pipeline.

[0008] In a preferred embodiment, a first shut-off check valve is installed on the pipeline through which the first manual shut-off valve C2 is located at the rear of the medium flow direction.

[0009] In a preferred embodiment, the pipeline connected in parallel to the first manual shut-off valve C2 is also provided with a pressure-reducing pipeline connected to the nitrogen supply end. The pressure-reducing pipeline is provided with a pressure-reducing valve B1 and a second shut-off check valve in sequence according to the direction of medium flow.

[0010] In the preferred embodiment, a safety valve C8 is connected in parallel with the second manual shut-off valve C9.

[0011] In the preferred embodiment, a discharge pipeline is set up by setting a terminal discharge valve C11; the discharge pipeline is connected to the return pipeline at the low point position by a low-end discharge valve C7 and a balance valve C10 in sequence according to the medium flow direction.

[0012] In a preferred embodiment, the discharge pipeline is also connected to the rear end pipelines of the second manual shut-off valve C9 and the safety valve C8.

[0013] In a preferred embodiment, a third shut-off check valve C6 is installed near the low point on the return pipeline connected to the nitrogen supply end.

[0014] This invention allows operation within a safe zone, preventing methanol from entering the atmospheric environment and ensuring operator safety. The invention incorporates a purging module that uses 13 bar nitrogen gas to purge leaked methanol from the annular zone into a methanol purging tank (suitable for large methanol leaks). The purging module first performs initial purging with 13 bar nitrogen gas, then uses a balancing valve to release the pressure in the annular zone to atmospheric pressure. Finally, a terminal purging valve is used to remove any remaining methanol using a portable purging tank, ultimately resolving the annular zone leakage problem.

[0015] This invention can quickly solve the problem of leakage in the annular region of the double-walled pipe of a methanol generator in the safe zone. It mainly targets leakage in the annular region of the methanol return pipeline, and uses a sealed measure to remove methanol from the annular region, thereby achieving rapid emptying of methanol from the annular region. It features simple design, convenient operation, and safe explosion-proof characteristics. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall system layout of a methanol dual-fuel generator;

[0017] Figure 2 yes Figure 1 The diagram shows a schematic of the layout of the return piping system of the present invention;

[0018] Figure 3 This is a schematic diagram of a system without a leak detection solution. In the diagram, A1: Pressure reducing valve; A2: Manual shut-off valve for methanol supply pipeline; A3: Relief module; A4: Shut-off check valve for methanol supply pipeline; A5: Methanol dual-fuel generator; A6: Shut-off check valve for the annular section of the double-walled pipe; A7: Safety valve; A8: Relief valve; B1: Pressure reducing valve; B2: Manual shut-off valve for methanol generator-side pipeline; B4: Shut-off check valve for methanol generator-side pipeline; B6: Shut-off check valve for the annular section of the double-walled pipe; B7: Relief valve; C2: First manual shut-off valve; C4: Shut-off check valve for methanol return pipeline; C6: Third shut-off check valve; C7: Relief valve; C8: Safety valve; C9: Second manual shut-off valve; C10: Balancing valve; C11: Terminal relief valve; f1: Engine room safety zone; f2: Nitrogen inlet; f3: Methanol inlet; f4: Double-walled pipe; f5: Nitrogen outlet; f6: Methanol return. Detailed Implementation

[0019] This invention discloses a double-walled pipe annular zone leak prevention safety system for the return pipeline of a methanol dual-fuel generator, such as... Figure 1 and Figure 2 As shown, it includes B1-pressure reducing valve, C2-first manual shut-off valve, A3-relief module, C4-stop check valve for methanol return pipeline, A5-methanol dual-fuel generator, C6-third shut-off check valve, C7-relief valve, C8-safety valve, C9-second manual shut-off valve, C10-balancing valve, and C11-terminal relief valve.

[0020] This also includes A1-pressure reducing valve, A2-manual shut-off valve for methanol supply pipeline, A4-stop check valve for methanol fuel supply pipeline, A6-stop check valve for the annular section of the double-walled pipe, A7-safety valve, A8-relief valve. B2-manual shut-off valve for methanol generator-side pipeline, B4-stop check valve for methanol generator-side pipeline, A5-methanol dual-fuel generator, B6-stop check valve for the annular section of the double-walled pipe, B7-relief valve.

[0021] contrast Figure 3 It is understood that the improvement of the present invention lies in that, for the annular area of ​​the double-walled pipe in the return pipeline, that is, the outer pipe area of ​​the double-walled pipe, a nitrogen purging system is set up to realize the purging of methanol leakage.

[0022] Specifically, the pressure reducing valve B1 is used to reduce the nitrogen pressure from 13 bar to 2 bar, filling the annular zone with 2 bar nitrogen. This creates an oxygen-free environment in the annular zone, ensuring that even if methanol leaks into the annular zone, there are no conditions for combustion or explosion. The first manual shut-off valve C2 is used to manually purge methanol from the annular zone into the venting tank. The venting module A3 connects the annular zone to the inner pipe of the double-walled pipe. The third shut-off check valve C6 is located within the venting module A3 to prevent nitrogen and methanol backflow. The methanol dual-fuel generator A5 is located in the engine room safety area. The venting valve C7 is used to release any remaining methanol that may be present. The safety valve C8 prevents overpressure in the annular zone of the double-walled pipe. The second manual shut-off valve C9 is used to manually purge any leaked methanol from the annular zone. The balancing valve C10 balances the pressure between the annular zone and the venting tank. The terminal venting valve C11 connects any remaining methanol in the annular zone to a portable venting tank.

[0023] The operating steps of this invention for methanol leakage in the return pipeline are as follows: When methanol leaks into the annular zone of the generator-side pipeline, first open the first manual shut-off valve C2 and the second manual shut-off valve C9, and use 13 bar nitrogen to blow the methanol in the annular zone into the methanol venting cabinet (suitable for situations with a large amount of methanol leakage). This step solves the problem of methanol returning to the annular zone of the pipeline and leaking; the nitrogen outlet is connected to the methanol venting cabinet.

[0024] Check if the level switch of the venting module A3 has returned to normal. The level switch is located at the lowest point of the venting module, so as long as there is residual methanol, it will be detected by the level switch. If the high level in the annular zone continues to alarm, repeat step 1 until the level switch in the annular zone of the venting module A3 returns to normal. When the first manual shut-off valve C2 is closed, the nitrogen in the annular zone gradually enters the inner tube of the double-walled pipe through the third shut-off check valve C6 in the venting module A3. The one-way setting value of the third shut-off check valve C6 is 2 bar. Nitrogen can only enter the inner tube from the annular zone through C6, but no liquid or gas in the inner tube can enter the annular zone through C6. When the nitrogen level drops to 2 bar, the annular zone continuously forms a 2 bar nitrogen-sealed inert gas safety environment. Pressure reducing valve B1 is used to reduce nitrogen from 13 bar to 2 bar for nitrogen sealing in the annular zone during daily operation of the generator. Check valve C4 in the methanol return pipeline is used to prevent nitrogen backflow and methanol backflow in case of possible internal pipe methanol leakage. Open the relief valve C7 and the balancing valve C10 to make the pressure in the annular zone consistent with the pressure in the relief cabinet, reaching atmospheric pressure.

[0025] Finally, open the terminal vent valve C11 and use the portable vent canister to remove the residual methanol. After carefully investigating the cause of the leak and eliminating the cause, the generator was restored to operation.

[0026] In summary, the characteristics of the cleaning process of this invention are as follows: Due to the limitations of the actual layout and pipe diameter in the annular section of the methanol return pipeline, it is impossible to purge methanol from the top down into the inner tube of the double-walled pipe. Nitrogen purging can only be carried out from the bottom up. During the actual purging process, when methanol is purged from the annular section into the inner tube, bubbling occurs, making it impossible to blow the leaking methanol into the inner tube. Therefore, the method of blowing methanol into the inner tube from the annular section cannot be used to address the leakage in the annular section of the methanol return pipeline. For methanol residues in the annular zone that cannot be purged by gravity, 13 bar nitrogen gas is first used to purge the methanol from the annular zone to the venting tank through a bypass valve (suitable for cases with large methanol leaks); For any remaining methanol in the annular area that cannot be emptied, first use the connecting valve to reduce the pressure and maintain it at the same 0.2 bar nitrogen sealing pressure as the venting tank to ensure operator safety. Then, use a portable canister to empty the remaining methanol.

[0027] exist Figure 1 , Figure 2 , Figure 3 In the diagram, f1 is the cabin safety zone; f2 is the nitrogen inlet; f3 is the methanol inlet; f4 is the double-walled pipe; f5 is the nitrogen outlet; and f6 is the methanol return line.

[0028] 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 leak-proof safety system for the annular zone of a methanol dual-fuel generator return pipeline, characterized in that, The methanol dual-fuel generator is equipped with a return pipeline in the form of a double-walled pipe; the inner pipe of the return pipeline is used to return methanol; the outer pipe of the return pipeline is connected to the nitrogen supply end, and then nitrogen is introduced. The return pipeline is connected to the nitrogen supply end at the low point by a first manual shut-off valve (C2); The return pipeline is connected to the nitrogen outlet of the methanol venting cabinet at the high point via a second manual shut-off valve (C9).

2. The methanol dual-fuel generator return pipeline double-walled pipe annular zone leak prevention safety system according to claim 1, characterized in that, A liquid level detection switch or a methanol detection sensor is also installed at the lowest point of the outer pipe of the double-walled return pipeline.

3. The methanol dual-fuel generator return pipeline double-walled pipe annular zone leak prevention safety system according to claim 1, characterized in that, A first shut-off check valve is installed on the pipeline where the first manual shut-off valve (C2) is located at the rear of the medium flow direction.

4. The methanol dual-fuel generator return pipeline double-walled pipe annular zone leak prevention safety system according to claim 1, characterized in that, The pipeline connected in parallel to the first manual shut-off valve (C2) is also provided with a pressure-reducing pipeline connected to the nitrogen supply end. The pressure-reducing pipeline is provided with a pressure-reducing valve (B1) and a second shut-off check valve in sequence according to the medium flow direction.

5. The methanol dual-fuel generator return pipeline double-walled pipe annular zone leak prevention safety system according to claim 1, characterized in that, A safety valve (C8) is connected in parallel to the second manual shut-off valve (C9).

6. The methanol dual-fuel generator return pipeline double-walled pipe annular zone leak prevention safety system according to claim 1, characterized in that, The discharge pipeline is configured by setting the terminal discharge valve (C11); The discharge pipeline is sequentially equipped with a low-end discharge valve (C7) and a balancing valve (C10) connected to the return pipeline at the low point position according to the medium flow direction.

7. The methanol dual-fuel generator return pipeline double-walled pipe annular zone leak prevention safety system according to claim 1, characterized in that, The venting line is also connected to the rear end lines of the second manual shut-off valve (C9) and the safety valve (C8).

8. The methanol dual-fuel generator return pipeline double-walled pipe annular zone leak prevention safety system according to claim 1, characterized in that, The return pipeline is connected to the nitrogen supply end at the low point, and a third shut-off check valve (C6) is installed near the low point.

Images