Residual methanol treatment system for bench test of methanol dual-fuel engine and use method of residual methanol treatment system

Abstract

The invention provides a methanol dual-fuel engine bench test residual methanol treatment system which comprises a methanol and diesel mixed supply pump, a first stop valve, a second stop valve, a third stop valve and a pressure reducing valve, the methanol and diesel mixed supply pump is in pipeline connection with the first stop valve, and the first stop valve, the second stop valve and the third stop valve are all in pipeline connection with the pressure reducing valve. And the methanol and diesel oil mixed supply pump, the second stop valve, the third stop valve and the pressure reducing valve are respectively used for pipeline connection with a methanol collection box, a methanol low-pressure supply pump unit, a bench diesel oil supply unit and a methanol high-pressure pump unit which are adopted by a methanol dual-fuel engine bench test. Related methods of use are also provided. The residual methanol treatment system for the bench test of the methanol dual-fuel engine can directly treat residual methanol in the methanol collection box without adding a methanol recovery tank and third-party recovery treatment, so that the site demand and the methanol hazard risk are reduced, the methanol treatment cost is reduced, and the residual methanol treatment system is suitable for large-scale popularization and application.

Description

Technical Field

[0001] The present invention relates to the technical field of engine bench test, more specifically, to the technical field of methanol dual-fuel engine bench test, and in particular to a methanol dual-fuel engine bench test residual methanol processing system and a use method thereof. Background Art

[0002] Engine bench testing refers to the testing and evaluation of various performance parameters of the engine on a specially designed test bench before the engine leaves the factory. This test method can simulate various states of the engine in actual work, such as the running state at different speeds and loads, so as to have a more comprehensive understanding of the engine's performance and potential problems.

[0003] See also Figure 1 As shown, the methanol dual-fuel engine bench test mainly adopts a methanol dual-fuel engine, a methanol storage tank, a methanol low-pressure supply pump unit, a methanol high-pressure pump unit, a bench diesel supply unit and a methanol collection box. The methanol storage tank is connected to the methanol high-pressure pump unit through the methanol low-pressure supply pump unit pipeline. The methanol high-pressure pump unit and the bench diesel supply unit are both connected to the methanol dual-fuel engine by pipelines. The methanol dual-fuel engine pipeline is connected to the methanol collection box. The methanol low-pressure supply pump unit is used to supply methanol from the methanol storage tank to the methanol high-pressure pump unit at a stable pressure of 5 bar to ensure the flow rate and temperature. The methanol low-pressure supply pump unit has a cooling and heating system and a temperature control valve to ensure that the temperature of the methanol outlet is controlled at about 25 degrees. The outlet of the methanol low-pressure supply pump unit is provided with a pressure regulating valve (adjustable from 5 to 8 bar) to ensure the outlet methanol pressure The pressure is controlled at 5bar; the methanol high-pressure pump unit is used to increase the 5bar methanol from the methanol low-pressure supply pump unit to 600bar and supply it to the methanol dual-fuel engine for combustion. The methanol high-pressure pump unit is a supporting equipment for the methanol dual-fuel engine. The pressure in front of the methanol high-pressure pump unit is required to be 4-5bar; since the methanol dual-fuel engine requires diesel as a pilot oil when the methanol mode is working normally, a bench diesel supply unit is required to supply 7-8bar diesel to the methanol dual-fuel engine; the methanol collection tank (500L) is used to collect the residual liquid of methanol and diesel after the methanol dual-fuel engine and pipeline are unloaded. The methanol collection tank is equipped with a liquid level sensor to display the liquid level in real time and can make high and low level alarms. The methanol collection tank is equipped with a nitrogen sealing system to ensure that the methanol gas concentration in the methanol collection tank is safe and explosion-free.

[0004] When the methanol dual-fuel engine is running in normal methanol mode: the bench diesel supply unit supplies diesel at 8 bar to the methanol dual-fuel engine as a pilot oil, and the methanol in the methanol storage tank is supplied to the methanol high-pressure pump unit through the methanol low-pressure supply pump unit (adjusting the pressure to 5 bar). The methanol high-pressure pump unit boosts the methanol to 600 bar and then supplies it to the methanol pipeline of the methanol dual-fuel engine for combustion. When the methanol dual-fuel engine switches from methanol mode to diesel mode: the methanol high-pressure pump unit stops running, the methanol inside the methanol dual-fuel engine is unloaded into the methanol collection tank, and the methanol dual-fuel engine runs with diesel.

[0005] When the methanol dual-fuel engine is undergoing bench testing, due to the engine's operating design, the methanol system and external methanol pipeline system on the methanol dual-fuel engine will be unloaded with methanol and purged with nitrogen under conditions such as switching from diesel mode to methanol mode, switching from methanol mode to diesel mode, methanol mode alarm and emergency stop test, and external methanol system failure. The unloaded and purged methanol liquid is collected in the methanol collection tank. In this way, a methanol dual-fuel engine will produce 50L-300L of residual methanol during bench testing. Since methanol is a hazardous waste, it is relatively cumbersome to handle.

[0006] The general treatment method is to install a large-capacity methanol recovery tank, transfer the methanol from the methanol collection tank to the methanol recovery tank, add water to dilute the methanol in the methanol recovery tank, and when the methanol recovery tank is almost full, ask a third party to use a methanol tank recovery truck to recycle it. However, this treatment has the following disadvantages:

[0007] 1. This design adds an additional methanol recovery tank, the capacity of the methanol recovery tank will be relatively large, and additional piping and equipment are added, which increases the site requirements.

[0008] 2. Additional methanol recovery tanks add additional risks. Methanol diluted with water will greatly increase the amount of third-party recycling, which is equivalent to increasing the factory's hazardous waste treatment volume.

[0009] Therefore, it is hoped to provide a residual methanol treatment system for a methanol dual-fuel engine bench test, which can directly treat the residual methanol in the methanol collection box without adding a methanol recovery tank and third-party recycling treatment, thereby reducing site requirements and methanol hazard risks and reducing methanol treatment costs. Summary of the invention

[0010] In order to overcome the shortcomings of the above-mentioned prior art, one object of the present invention is to provide a residual methanol processing system for a methanol dual-fuel engine bench test, which can directly process the residual methanol in the methanol collection box without adding a methanol recovery tank and third-party recovery processing, thereby reducing site requirements and methanol hazard risks, reducing methanol processing costs, and being suitable for large-scale promotion and application.

[0011] Another object of the present invention is to provide a method for using a residual methanol treatment system for a methanol dual-fuel engine bench test. This method can directly treat the residual methanol in the methanol collection box without adding a methanol recovery tank and third-party recovery treatment, thereby reducing site requirements and methanol hazard risks, reducing methanol treatment costs, and being suitable for large-scale promotion and application.

[0012] To achieve the above objectives, in a first aspect of the present invention, a residual methanol treatment system for a methanol dual-fuel engine bench test is provided, which is characterized in that it includes a methanol-diesel mixed supply pump, a first shut-off valve, a second shut-off valve, a third shut-off valve and a pressure reducing valve, wherein:

[0013] The methanol-diesel mixed supply pump pipeline is connected to the first cut-off valve, and the first cut-off valve, the second cut-off valve and the third cut-off valve are all connected to the pressure reducing valve through pipelines. The methanol-diesel mixed supply pump, the second cut-off valve, the third cut-off valve and the pressure reducing valve are respectively used for pipeline connection of the methanol collection tank, the methanol low-pressure supply pump unit, the bench diesel supply unit and the methanol high-pressure pump unit used in the methanol dual-fuel engine bench test.

[0014] Preferably, the methanol-diesel mixed supply pump is a screw pump.

[0015] Preferably, the first cut-off valve, the second cut-off valve and the third cut-off valve are all electrically controlled pneumatic valves.

[0016] Preferably, the residual methanol processing system for the methanol dual-fuel engine bench test also includes a first check valve, a second check valve and a third check valve, and the first cut-off valve, the second cut-off valve and the third cut-off valve are connected to the pressure reducing valve through the first check valve, the second check valve and the third check valve pipelines respectively.

[0017] Preferably, the residual methanol processing system for the methanol dual-fuel engine bench test further comprises a pressure regulating valve, and the methanol-diesel mixed supply pump is connected to the first shut-off valve via a pipeline of the pressure regulating valve.

[0018] Preferably, the methanol dual-fuel engine bench test residual methanol processing system also includes a first connecting pipe and a second connecting pipe, the third cut-off valve is connected to the pressure reducing valve through the first connecting pipe pipeline, the second cut-off valve is connected to the first connecting pipe through the second connecting pipe pipeline, and the first cut-off valve pipeline is connected to the second connecting pipe.

[0019] In a second aspect of the present invention, a method for using the above-mentioned methanol dual-fuel engine bench test residual methanol treatment system is provided, which is characterized by comprising the following steps:

[0020] (1) The methanol-diesel mixed supply pump, the second shut-off valve, the third shut-off valve and the pressure reducing valve are respectively connected to the methanol collection tank, the methanol low-pressure supply pump unit, the bench diesel supply unit and the methanol high-pressure pump unit through pipelines;

[0021] (2) When the methanol dual-fuel engine is in normal methanol mode: the second shut-off valve is opened, the first shut-off valve and the third shut-off valve are closed, diesel is supplied to the methanol dual-fuel engine as pilot oil through the bench diesel supply unit, methanol in the methanol storage tank is supplied to the pressure reducing valve through the methanol low-pressure supply pump unit, and is supplied to the methanol high-pressure pump unit after being reduced in pressure by the pressure reducing valve, and is supplied to the methanol dual-fuel engine methanol pipeline for combustion after being pressurized by the methanol high-pressure pump unit;

[0022] (3) When the methanol dual-fuel engine is switched from methanol mode to diesel mode: the methanol high-pressure pump unit is stopped, the first shut-off valve, the second shut-off valve and the third shut-off valve are closed, the methanol in the methanol dual-fuel engine is discharged into the methanol collection tank, and the methanol dual-fuel engine is operated with diesel;

[0023] (4) Methanol collection tank waste liquid treatment:

[0024] When the liquid level of the waste liquid in the methanol collection tank reaches the liquid level to be treated, the second shut-off valve and the third shut-off valve are closed, the first shut-off valve is opened, the waste liquid in the methanol collection tank is supplied to the pressure reducing valve through the methanol-diesel mixed supply pump, and is supplied to the methanol high-pressure pump unit after being reduced in pressure by the pressure reducing valve, the methanol dual-fuel engine is first started in diesel mode, and then the methanol dual-fuel engine is switched to methanol mode, and the waste liquid is pressurized by the methanol high-pressure pump unit and supplied to the methanol pipeline of the methanol dual-fuel engine for combustion;

[0025] When the level of the waste liquid in the methanol collection tank drops to a level where treatment needs to be stopped, the methanol dual-fuel engine is switched to diesel mode, the methanol high-pressure pump unit and the methanol-diesel mixed supply pump are stopped, the first shut-off valve is closed, and the methanol dual-fuel engine operates in diesel mode.

[0026] Preferably, in step (2), diesel is supplied to the methanol dual-fuel engine at 8 bar as pilot oil through the bench diesel supply unit, methanol in the methanol storage tank is supplied to the pressure reducing valve at 6 bar through the methanol low-pressure supply pump unit, and then supplied to the methanol high-pressure pump unit at 4 bar after being reduced in pressure by the pressure reducing valve, and then supplied to the methanol dual-fuel engine methanol pipeline at 600 bar after being pressurized by the methanol high-pressure pump unit for combustion.

[0027] Preferably, in step (4), the waste liquid in the methanol collection tank is supplied to the pressure reducing valve at 6 bar through the methanol-diesel mixed supply pump, and is supplied to the methanol high-pressure pump unit at 4 bar after being reduced in pressure by the pressure reducing valve, and the waste liquid is pressurized by the methanol high-pressure pump unit and is supplied to the methanol dual-fuel engine methanol pipeline for combustion at 600 bar.

[0028] Preferably, the method of use further comprises:

[0029] (5) After the methanol dual-fuel engine ends its operation in methanol mode, use diesel to wash the methanol pipeline before shutting down;

[0030] The methanol dual-fuel engine is switched to diesel mode operation, the methanol high-pressure pump unit and the methanol-diesel mixed supply pump are stopped, the first shut-off valve and the second shut-off valve are closed, the third shut-off valve is opened, diesel is supplied to the pressure reducing valve through the bench diesel supply unit, and the diesel is supplied to the methanol high-pressure pump unit after being reduced in pressure by the pressure reducing valve, and when the methanol dual-fuel engine is 50% loaded, the methanol dual-fuel engine is switched to methanol mode, diesel is boosted by the methanol high-pressure pump unit and supplied to the methanol dual-fuel engine after the methanol pipeline burns for a preset time, the methanol dual-fuel engine is switched to diesel mode, the methanol high-pressure pump unit is stopped, the third shut-off valve is closed, and the methanol dual-fuel engine is shut down.

[0031] The beneficial effects of the present invention are:

[0032] 1. The residual methanol processing system for a methanol dual-fuel engine bench test of the present invention comprises a methanol-diesel mixed supply pump, a first shut-off valve, a second shut-off valve, a third shut-off valve and a pressure reducing valve. The methanol-diesel mixed supply pump is connected to the first shut-off valve through a pipeline, and the first shut-off valve, the second shut-off valve and the third shut-off valve are all connected to the pressure reducing valve through pipelines. The methanol-diesel mixed supply pump, the second shut-off valve, the third shut-off valve and the pressure reducing valve are respectively used for connecting the methanol collection box, the methanol low-pressure supply pump unit, the bench diesel supply unit and the methanol high-pressure pump unit used in the methanol dual-fuel engine bench test through pipelines. Therefore, the residual methanol in the methanol collection box can be directly processed without adding a methanol recovery tank and third-party recovery processing, thereby reducing site requirements and methanol hazard risks, reducing methanol processing costs, and being suitable for large-scale promotion and application.

[0033] 2. The method for using the residual methanol treatment system of the methanol dual-fuel engine bench test of the present invention comprises: when the liquid level of the waste liquid in the methanol collection box reaches the liquid level to be treated, the second shut-off valve and the third shut-off valve are closed, the first shut-off valve is opened, the waste liquid in the methanol collection box is supplied to the pressure reducing valve through the methanol-diesel mixed supply pump, and the waste liquid is supplied to the methanol high-pressure pump unit after being reduced in pressure through the pressure reducing valve, the methanol dual-fuel engine is first started in the diesel mode, and then the methanol dual-fuel engine is switched to the methanol mode, and the waste liquid is pressurized by the methanol high-pressure pump unit and then supplied to the methanol pipeline of the methanol dual-fuel engine for combustion; when the liquid level of the waste liquid in the methanol collection box is reduced to the liquid level to be stopped, the methanol dual-fuel engine is switched to the diesel mode, the methanol high-pressure pump unit and the methanol-diesel mixed supply pump are stopped, the first shut-off valve is closed, and the methanol dual-fuel engine is operated in the diesel mode. Therefore, the residual methanol in the methanol collection box can be directly treated by adopting this method, without adding a methanol recovery tank and third-party recovery treatment, reducing site requirements and methanol hazard risks, reducing methanol treatment costs, and being suitable for large-scale promotion and application.

[0034] These and other objects, features and advantages of the present invention will be more fully reflected in the following detailed description and claims, and may be achieved by the means, devices and combinations thereof particularly pointed out in the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a schematic diagram of the connection structure of multiple devices used in the methanol dual-fuel engine bench test.

[0036] Figure 2 It is a structural schematic diagram of a specific embodiment of the residual methanol processing system for a methanol dual-fuel engine bench test of the present invention.

[0037] Figure 3 Yes Figure 2 The specific embodiment shown is Figure 1 The diagram shows the structure of multiple equipment connections used in the methanol dual-fuel engine bench test.

[0038] (Explanation of symbols)

[0039] 1 methanol-diesel mixed supply pump; 2 first shut-off valve; 3 second shut-off valve; 4 third shut-off valve; 5 first check valve; 6 second check valve; 7 third check valve; 8 first connecting pipeline; 9 second connecting pipeline. DETAILED DESCRIPTION

[0040] In order to timely treat the residual methanol in the methanol collection box without adding methanol recovery tanks and third-party recycling processing, reduce site requirements and methanol hazard risks, and reduce methanol processing costs, the inventors have proposed a methanol dual-fuel engine bench test residual methanol processing system through in-depth and extensive research.

[0041] See also Figure 2 As shown, in a specific embodiment of the present invention, the residual methanol processing system of the methanol dual-fuel engine bench test of the present invention comprises a methanol-diesel mixed supply pump 1, a first shut-off valve 2, a second shut-off valve 3, a third shut-off valve 4 and a pressure reducing valve, wherein:

[0042] The methanol-diesel mixed supply pump 1 is connected to the first cut-off valve 2 through a pipeline, and the first cut-off valve 2, the second cut-off valve 3 and the third cut-off valve 4 are all connected to the pressure reducing valve through pipelines. The methanol-diesel mixed supply pump 1, the second cut-off valve 3, the third cut-off valve 4 and the pressure reducing valve are respectively used for connecting the methanol collection box, the methanol low-pressure supply pump unit, the bench diesel supply unit and the methanol high-pressure pump unit used in the methanol dual-fuel engine bench test through pipelines.

[0043] The methanol-diesel mixed supply pump 1 can be any suitable supply pump. In a specific embodiment of the present invention, the methanol-diesel mixed supply pump 1 is a screw pump.

[0044] The pressure reducing valve may be any suitable pressure reducing valve. In a specific embodiment of the present invention, the pressure reducing valve is a mechanical self-supporting pressure reducing valve. The pressure regulating range of the mechanical self-supporting pressure reducing valve may be, for example, 6-8 bar before the valve and 4-5 bar after the valve.

[0045] The first cut-off valve 2, the second cut-off valve 3 and the third cut-off valve 4 can be any suitable cut-off valves. In a specific embodiment of the present invention, the first cut-off valve 2, the second cut-off valve 3 and the third cut-off valve 4 are all electrically controlled pneumatic valves. With the above arrangement, the corresponding pipelines can be remotely switched on and off.

[0046] The residual methanol processing system for the methanol dual-fuel engine bench test may also include any other suitable components, see Figure 2 As shown, in a specific embodiment of the present invention, the residual methanol processing system for the methanol dual-fuel engine bench test further includes a first check valve 5, a second check valve 6 and a third check valve 7, and the first cut-off valve 2, the second cut-off valve 3 and the third cut-off valve 4 are respectively connected to the pressure reducing valve through the first check valve 5, the second check valve 6 and the third check valve 7. The above arrangement can ensure that different media will not flow back.

[0047] The methanol dual-fuel engine bench test residual methanol processing system may also include any other suitable components. In a specific embodiment of the present invention, the methanol dual-fuel engine bench test residual methanol processing system further includes a pressure regulating valve (not shown in the figure), and the methanol-diesel mixed supply pump 1 is connected to the first shut-off valve 2 through the pressure regulating valve pipeline. With the above arrangement, the outlet pressure of the methanol-diesel mixed supply pump 1 is ensured to be, for example, 6 bar through the pressure regulating valve.

[0048] The residual methanol processing system for the methanol dual-fuel engine bench test may also include any other suitable components, see Figure 2 As shown, in a specific embodiment of the present invention, the residual methanol processing system for the methanol dual-fuel engine bench test further includes a first connecting pipeline 8 and a second connecting pipeline 9, the third shut-off valve 4 is connected to the pressure reducing valve through the first connecting pipeline 8, the second shut-off valve 3 is connected to the first connecting pipeline 8 through the second connecting pipeline 9, and the first shut-off valve 2 is connected to the second connecting pipeline 9. In the case where the residual methanol processing system for the methanol dual-fuel engine bench test further includes a first check valve 5, a second check valve 6 and a third check valve 7, the third shut-off valve 4 is connected to the first connecting pipeline 8 through the third check valve 7 pipeline, the second shut-off valve 3 is connected to the second connecting pipeline 9 through the second check valve 6 pipeline, and the first shut-off valve 2 is connected to the second connecting pipeline 9 through the first check valve 5 pipeline.

[0049] The method of use of the present invention is briefly described as follows:

[0050] (1) Please see Figure 3 As shown, the methanol-diesel mixed supply pump 1, the second shut-off valve 3, the third shut-off valve 4 and the pressure reducing valve are respectively connected to the methanol collection tank, the methanol low-pressure supply pump unit, the bench diesel supply unit and the methanol high-pressure pump unit by pipelines;

[0051] (2) When the methanol dual-fuel engine is operating in normal methanol mode: the second shut-off valve 3 is opened, the first shut-off valve 2 and the third shut-off valve 4 are closed, diesel is supplied to the methanol dual-fuel engine at 8 bar as pilot oil through the bench diesel supply unit, methanol in the methanol storage tank is supplied to the pressure reducing valve at 6 bar through the methanol low-pressure supply pump unit, and is supplied to the methanol high-pressure pump unit at 4 bar after being reduced in pressure by the pressure reducing valve, and is supplied to the methanol dual-fuel engine methanol pipeline at 600 bar after being pressurized by the methanol high-pressure pump unit for combustion;

[0052] (3) When the methanol dual-fuel engine is switched from methanol mode to diesel mode: the methanol high-pressure pump unit is stopped, the first shut-off valve 2, the second shut-off valve 3 and the third shut-off valve 4 are closed, the methanol in the methanol dual-fuel engine is discharged into the methanol collection tank, and the methanol dual-fuel engine is operated with diesel;

[0053] (4) Methanol collection tank waste liquid treatment:

[0054] When the liquid level of the waste liquid in the methanol collection tank reaches the liquid level to be treated, the second shut-off valve 3 and the third shut-off valve 4 are closed, the first shut-off valve 2 is opened, the waste liquid in the methanol collection tank is supplied to the pressure reducing valve at 6 bar through the methanol-diesel mixed supply pump 1, and is supplied to the methanol high-pressure pump unit at 4 bar after being reduced in pressure by the pressure reducing valve, the methanol dual-fuel engine is first started in diesel mode, and then the methanol dual-fuel engine is switched to methanol mode, and the waste liquid is pressurized by the methanol high-pressure pump unit and supplied to the methanol pipeline of the methanol dual-fuel engine at 600 bar for combustion, so that the waste liquid in the methanol collection tank is burned by the methanol dual-fuel engine;

[0055] When the liquid level of the waste liquid in the methanol collection tank drops to a level at which treatment needs to be stopped, the methanol dual-fuel engine is switched to the diesel mode, the methanol high-pressure pump unit and the methanol-diesel mixed supply pump 1 are stopped, the first shut-off valve 2 is closed, and the methanol dual-fuel engine is operated in the diesel mode;

[0056] Before the bench test is completed, diesel fuel washing can also be used. The method of using the present invention also includes:

[0057] (5) After the methanol dual-fuel engine ends its operation in methanol mode, use diesel to wash the methanol pipeline before shutting down;

[0058] The methanol dual-fuel engine is switched to diesel mode, the methanol high-pressure pump unit and the methanol-diesel mixed supply pump 1 are stopped, the first shut-off valve 2 and the second shut-off valve 3 are closed, the third shut-off valve 4 is opened, the diesel is supplied to the pressure reducing valve at 8 bar through the bench diesel supply unit, and the diesel is supplied to the methanol high-pressure pump unit at 5 bar after being reduced in pressure by the pressure reducing valve. When the methanol dual-fuel engine is 50% loaded, the methanol dual-fuel engine is switched to methanol mode, the diesel is boosted by the methanol high-pressure pump unit and supplied to the methanol dual-fuel engine at 600 bar for methanol pipeline combustion (since the calorific value of methanol is half that of diesel, the operator can manually adjust the parameters of the methanol dual-fuel engine to ensure the normal operation of the methanol dual-fuel engine). After the preset time of 10 minutes, the methanol dual-fuel engine is switched to diesel mode, the methanol high-pressure pump unit is stopped, the third shut-off valve 4 is closed, and the methanol dual-fuel engine is shut down.

[0059] It can be understood that the liquid level that needs to be treated is the higher liquid level of the methanol collecting tank, the liquid level that needs to stop treatment is the lower liquid level of the methanol collecting tank, and the preset time is the time for washing the methanol pipeline with diesel. The liquid level that needs to be treated, the liquid level that needs to stop treatment and the preset time can be set in advance according to needs.

[0060] Therefore, the present invention proposes a methanol dual-fuel engine bench test residual methanol processing system, which is used to process the residual methanol generated in the methanol dual-fuel engine bench test. The methanol dual-fuel engine bench test residual methanol processing system of the present invention is adopted, by canceling the methanol recovery tank, adding a set of pump groups and control valve groups between the methanol collection box, the methanol low-pressure supply pump unit, the bench diesel supply unit and the methanol high-pressure pump unit. When the liquid level in the methanol collection box reaches a certain level, the methanol in the methanol collection box is pumped back to the methanol dual-fuel engine for combustion. After the methanol dual-fuel engine burns methanol, it switches to diesel, and uses diesel to burn for a certain period of time to ensure that there is no methanol in the pipeline, and then unloads and flushes the methanol dual-fuel engine and pipeline. In this way, after stopping the test, the methanol dual-fuel engine and the methanol pipeline are full of diesel, and the safety of personnel is guaranteed when disassembling and assembling the pipeline.

[0061] In summary, the residual methanol processing system for the methanol dual-fuel engine bench test of the present invention can directly process the residual methanol in the methanol collection box without adding a methanol recovery tank and third-party recovery processing, thereby reducing site requirements and methanol hazard risks, reducing methanol processing costs, and being suitable for large-scale promotion and application.

[0062] In this specification, the present invention has been described with reference to specific embodiments thereof. However, it is apparent that various modifications and variations may be made without departing from the spirit and scope of the present invention. Therefore, the description should be regarded as illustrative rather than restrictive.

Claims

1. A methanol dual-fuel engine bench test residual methanol treatment system, characterized in that: It includes a methanol-diesel mixed supply pump, a first cut-off valve, a second cut-off valve, a third cut-off valve and a pressure reducing valve, wherein: The methanol-diesel mixed supply pump pipeline is connected to the first cut-off valve, and the first cut-off valve, the second cut-off valve and the third cut-off valve are all connected to the pressure reducing valve through pipelines. The methanol-diesel mixed supply pump, the second cut-off valve, the third cut-off valve and the pressure reducing valve are respectively used for pipeline connection of the methanol collection tank, the methanol low-pressure supply pump unit, the bench diesel supply unit and the methanol high-pressure pump unit used in the methanol dual-fuel engine bench test.

2. The residual methanol treatment system for a methanol dual-fuel engine bench test according to claim 1 is characterized in that: The methanol-diesel mixed supply pump is a screw pump.

3. The residual methanol treatment system for a methanol dual-fuel engine bench test according to claim 1 is characterized in that: The first cut-off valve, the second cut-off valve and the third cut-off valve are all electrically controlled pneumatic valves.

4. The residual methanol treatment system for a methanol dual-fuel engine bench test according to claim 1 is characterized in that: The residual methanol processing system for the methanol dual-fuel engine bench test also includes a first check valve, a second check valve and a third check valve, and the first cut-off valve, the second cut-off valve and the third cut-off valve are connected to the pressure reducing valve through the first check valve, the second check valve and the third check valve pipelines respectively.

5. The residual methanol treatment system for a methanol dual-fuel engine bench test according to claim 1 is characterized in that: The residual methanol processing system for the methanol dual-fuel engine bench test further includes a pressure regulating valve, and the methanol-diesel mixed supply pump is connected to the first shut-off valve through the pressure regulating valve pipeline.

6. The residual methanol treatment system for a methanol dual-fuel engine bench test according to claim 1 is characterized in that: The residual methanol processing system for the methanol dual-fuel engine bench test also includes a first connecting pipe and a second connecting pipe. The third cut-off valve is connected to the pressure reducing valve via the first connecting pipe pipeline, the second cut-off valve is connected to the first connecting pipe via the second connecting pipe pipeline, and the first cut-off valve pipeline is connected to the second connecting pipe.

7. A method for using the residual methanol treatment system for a methanol dual-fuel engine bench test according to claim 1, characterized in that: The following steps are involved: (1) The methanol-diesel mixed supply pump, the second shut-off valve, the third shut-off valve and the pressure reducing valve are respectively connected to the methanol collection tank, the methanol low-pressure supply pump unit, the bench diesel supply unit and the methanol high-pressure pump unit through pipelines; (2) When the methanol dual-fuel engine is in normal methanol mode: the second shut-off valve is opened, the first shut-off valve and the third shut-off valve are closed, diesel is supplied to the methanol dual-fuel engine as pilot oil through the bench diesel supply unit, methanol in the methanol storage tank is supplied to the pressure reducing valve through the methanol low-pressure supply pump unit, and is supplied to the methanol high-pressure pump unit after being reduced in pressure by the pressure reducing valve, and is supplied to the methanol dual-fuel engine methanol pipeline for combustion after being pressurized by the methanol high-pressure pump unit; (3) When the methanol dual-fuel engine is switched from methanol mode to diesel mode: the methanol high-pressure pump unit is stopped, the first shut-off valve, the second shut-off valve and the third shut-off valve are closed, the methanol in the methanol dual-fuel engine is discharged into the methanol collection tank, and the methanol dual-fuel engine is operated with diesel; (4) Methanol collection tank waste liquid treatment: When the liquid level of the waste liquid in the methanol collection tank reaches the liquid level to be treated, the second shut-off valve and the third shut-off valve are closed, the first shut-off valve is opened, the waste liquid in the methanol collection tank is supplied to the pressure reducing valve through the methanol-diesel mixed supply pump, and is supplied to the methanol high-pressure pump unit after being reduced in pressure by the pressure reducing valve, the methanol dual-fuel engine is first started in diesel mode, and then the methanol dual-fuel engine is switched to methanol mode, and the waste liquid is pressurized by the methanol high-pressure pump unit and supplied to the methanol pipeline of the methanol dual-fuel engine for combustion; When the level of the waste liquid in the methanol collection tank drops to a level where treatment needs to be stopped, the methanol dual-fuel engine is switched to diesel mode, the methanol high-pressure pump unit and the methanol-diesel mixed supply pump are stopped, the first shut-off valve is closed, and the methanol dual-fuel engine operates in diesel mode.

8. The method of use according to claim 7, characterized in that: In the step (2), diesel is supplied to the methanol dual-fuel engine at 8 bar as a pilot oil through the bench diesel supply unit, methanol in the methanol storage tank is supplied to the pressure reducing valve at 6 bar through the methanol low-pressure supply pump unit, and is supplied to the methanol high-pressure pump unit at 4 bar after being reduced in pressure by the pressure reducing valve, and methanol is pressurized by the methanol high-pressure pump unit and supplied to the methanol dual-fuel engine methanol pipeline for combustion at 600 bar.

9. The method of use according to claim 7, characterized in that: In the step (4), the waste liquid in the methanol collection tank is supplied to the pressure reducing valve at 6 bar through the methanol-diesel mixed supply pump, and is supplied to the methanol high-pressure pump unit at 4 bar after being reduced in pressure by the pressure reducing valve. The waste liquid is pressurized by the methanol high-pressure pump unit and is supplied to the methanol dual-fuel engine methanol pipeline for combustion at 600 bar.

10. The method of use according to claim 7, characterized in that: The method of use also includes: (5) After the methanol dual-fuel engine ends its operation in methanol mode, use diesel to wash the methanol pipeline before shutting down; The methanol dual-fuel engine is switched to diesel mode operation, the methanol high-pressure pump unit and the methanol-diesel mixed supply pump are stopped, the first shut-off valve and the second shut-off valve are closed, the third shut-off valve is opened, diesel is supplied to the pressure reducing valve through the bench diesel supply unit, and the diesel is supplied to the methanol high-pressure pump unit after being reduced in pressure by the pressure reducing valve, and when the methanol dual-fuel engine is 50% loaded, the methanol dual-fuel engine is switched to methanol mode, diesel is boosted by the methanol high-pressure pump unit and supplied to the methanol dual-fuel engine after the methanol pipeline burns for a preset time, the methanol dual-fuel engine is switched to diesel mode, the methanol high-pressure pump unit is stopped, the third shut-off valve is closed, and the methanol dual-fuel engine is shut down.

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