Methanol discharge method, methanol supply system and engine
By using pressure sensors and inert gas to control the opening and closing of the methanol injector in the methanol supply system, the problem of methanol residues cannot be discharged is solved, and the safety of the methanol supply system is improved.
Patent Information
- Application Number
- CN202510745892.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-05
- Publication Date
- 2025-08-19
AI Technical Summary
In the prior art, when the methanol supply system exits the methanol mode, the methanol residue between the methanol injector inlet and the discharge solenoid valve cannot be completely discharged, resulting in a high risk of methanol leakage and insufficient safety.
By obtaining the exit methanol mode signal, close the methanol supply valve and injector, and open the drain valve to discharge residual methanol; use the pressure sensor to detect the pipeline pressure, control the inert gas supply and the opening and closing of the methanol injector to ensure that the methanol is completely discharged.
Complete emptiation of residual methanol in the methanol supply system is achieved, reducing the risk of methanol leakage and improving the safety of the system.
Smart Images
Figure CN120506318A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of methanol supply, and in particular to a methanol discharge method, a methanol supply system and an engine. Background Art
[0002] Large-bore methanol engines are high-power engines that use methanol as their primary fuel or in combination with other fuels. They are commonly used in marine applications, large generator sets, and other fields. Large-bore methanol engines can operate in either diesel or methanol mode. In methanol mode, diesel fuel ignites methanol to generate power.
[0003] Because methanol is toxic, prolonged exposure to it can damage the human central nervous system, respiratory system, and digestive system. Therefore, to ensure the safe operation of methanol engines, the methanol supply system must be purged of methanol when the engine exits methanol mode.
[0004] However, in the prior art, when the methanol in the methanol supply system is emptied, the methanol residue between the methanol injector inlet and the discharge solenoid valve cannot be discharged, resulting in the risk of methanol leakage in the methanol supply system and a high safety risk. Summary of the Invention
[0005] The present invention provides a methanol discharge method, a methanol supply system and an engine, so as to reduce the risk of methanol leakage and improve safety.
[0006] According to one aspect of the present invention, a methanol discharge method is provided, which is applied to a methanol supply system. The methanol supply system includes: a methanol supply valve, an inlet pipeline, a methanol injector, a discharge valve, a pressure sensor, an inert gas supply valve, and a methanol pipeline. The methanol discharge method includes:
[0007] Get the signal to exit methanol mode;
[0008] closing the methanol supply valve and the methanol injector based on the methanol mode exit signal, and opening the drain valve;
[0009] detecting the pressure in the methanol pipeline based on the pressure sensor to obtain a first pressure;
[0010] When the first pressure reaches a first preset pressure, closing the relief valve and opening the inert gas supply valve;
[0011] detecting the pressure in the methanol pipeline based on the pressure sensor to obtain a second pressure;
[0012] When the second pressure reaches a second preset pressure, opening the methanol injector;
[0013] After a first delay time, the methanol injector is closed; wherein the first time is the time required for the methanol in the inlet pipeline to be discharged.
[0014] Optionally, after the first delay time, after closing the methanol injector, the method further includes:
[0015] Close the inert gas supply valve and open the drain valve.
[0016] Optionally, after closing the inert gas supply valve and opening the discharge valve, the method further comprises:
[0017] When the second pressure reaches the first preset pressure, the relief valve is closed.
[0018] Optionally, a specific method for obtaining the first time includes:
[0019] Obtaining the methanol flow rate under the engine operating condition when the methanol mode exit signal is issued;
[0020] Calculating the residual methanol mass in the inlet pipeline according to the pipeline volume of the inlet pipeline, the number of pipelines of the inlet pipeline, and the methanol density;
[0021] The first time is calculated based on the residual methanol mass and the methanol flow rate under the engine working condition when the exit methanol mode signal is issued.
[0022] According to another aspect of the present invention, a methanol supply system is provided, comprising: a controller, a methanol supply valve, a relief valve, a pressure sensor, an inert gas supply valve, a methanol pipeline, at least one inlet pipeline, and at least one methanol injector;
[0023] The controller is respectively connected to the methanol supply valve, the methanol injector, the discharge valve, the pressure sensor and the inert gas supply valve, and is used to execute the methanol discharge method described in any one of the above embodiments;
[0024] The discharge valve and the pressure sensor are both connected to the methanol pipeline, the methanol supply valve is connected between the methanol storage device and the methanol pipeline, the inert gas supply valve is connected between the inert gas storage device and the methanol pipeline, the methanol supply valve and the inert gas supply valve are connected to the same position of the methanol pipeline, the discharge valve is also connected to the methanol recovery cabinet, the methanol injector is connected to the methanol pipeline through the inlet pipeline, and the methanol pipeline is used to transport methanol or inert gas; wherein, the methanol injector is connected to the inlet pipeline in a one-to-one correspondence.
[0025] Optionally, the methanol supply valve is a stop valve.
[0026] Optionally, the discharge valve is a solenoid valve; and the inert gas supply valve is a solenoid valve.
[0027] Optionally, the inert gas is nitrogen.
[0028] Optionally, the methanol supply system further comprises: a discharge pipeline and at least one connecting pipeline;
[0029] The discharge pipeline is connected to the methanol pipeline through the connecting pipeline, and the discharge valve is connected between the discharge pipeline and the methanol recovery cabinet.
[0030] According to another aspect of the present invention, there is further provided an engine, comprising: at least one cylinder and the methanol supply system according to any one of the above embodiments;
[0031] Each of the cylinders is connected to each of the methanol injectors in the methanol supply system in a one-to-one correspondence.
[0032] In an embodiment of the present invention, based on a methanol mode exit signal, the methanol supply valve and the methanol injector are closed, and the bleed valve is opened. A pressure sensor is used to detect a first pressure within the methanol pipeline. When the first pressure reaches a first preset pressure, the bleed valve is closed and the inert gas supply valve is opened. A pressure sensor is used to detect a second pressure within the methanol pipeline. When the second pressure reaches a second preset pressure, the methanol injector is opened and, after a first delay, the methanol injector is closed. After the methanol in the methanol pipeline is discharged, an inert gas is introduced into the methanol pipeline to apply pressure to the methanol in the inlet pipeline, thereby completely discharging the methanol in the inlet pipeline through the methanol injector under pressure. This effectively empties any residual methanol in the methanol supply system, thereby reducing the risk of methanol leakage and improving safety.
[0033] It should be understood that the content described in this section is not intended to identify the key or important features of the embodiments of the present invention, nor is it intended to limit the scope of the present invention. Other features of the present invention will become readily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS
[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.
[0035] Figure 1 is a schematic diagram of a methanol supply system provided by an embodiment of the present invention;
[0036] Figure 2 Schematic diagram of a methanol discharge method provided by an embodiment of the present invention;
[0037] Figure 3 Schematic diagram of another methanol discharge method provided by an embodiment of the present invention;
[0038] Figure 4 Schematic diagram of another methanol discharge method provided by an embodiment of the present invention;
[0039] Figure 5 Schematic diagram of an engine provided by an embodiment of the present invention. DETAILED DESCRIPTION
[0040] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.
[0041] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.
[0042] Embodiments of the present invention provide a methanol discharge method applicable to a methanol supply system to discharge and empty residual methanol when the system is shut down. The methanol supply system is provided with a controller that can be used to execute the methanol discharge method provided by any embodiment of the present invention. To facilitate understanding of the methanol discharge method provided by embodiments of the present invention, the structure of the methanol supply system used in the methanol discharge method will first be described.
[0043] Figure 1 Schematic diagram of a methanol supply system provided by an embodiment of the present invention. Figure 1The methanol supply system includes: a controller 3, a methanol supply valve 1, a relief valve 10, a pressure sensor 9, an inert gas supply valve 2, a methanol pipeline 4, at least one inlet pipeline 8 and at least one methanol injector 5.
[0044] The controller 3 is respectively connected to the methanol supply valve 1 , the methanol injector 5 , the discharge valve 10 , the pressure sensor 9 and the inert gas supply valve 2 . The controller 3 is used to execute the methanol discharge method provided in any of the above embodiments.
[0045] A discharge valve 10 and a pressure sensor 9 are both connected to the methanol pipeline 4. A methanol supply valve 1 is connected between the methanol storage device 31 and the methanol pipeline 4. An inert gas supply valve 2 is connected between the inert gas storage device 21 and the methanol pipeline 4. The methanol supply valve 1 and the inert gas supply valve 2 are connected to the same location on the methanol pipeline 4. The discharge valve 10 is also connected to the methanol recovery cabinet 12. A methanol injector 5 is connected to the methanol pipeline 4 via an inlet pipeline 8. The methanol pipeline 4 is used to transport methanol or inert gas. There is a one-to-one correspondence between the methanol injectors 5 and the inlet pipelines 8.
[0046] In practical applications, the methanol supply system may also be provided with a discharge line 7. A discharge valve 10 is connected to the methanol line 4 via the discharge line 7. A connecting line 11 may be provided between the discharge line 7 and the methanol line 4. Each inlet line 8 is connected to the discharge line 7, and the connecting line 11 may correspond one-to-one with each inlet line 8. In practical applications, the discharge line 7 may be located near the methanol injector 5 to reduce the length of the inlet line 8 and thereby reduce the amount of methanol remaining in the inlet line 8. Since the methanol in the inlet line 8 cannot be discharged to the methanol recovery tank 12 via the discharge valve 10, the remaining methanol in the inlet line 8 can only be discharged through the methanol injector 5, thereby discharging the methanol in the inlet line 8. The discharged methanol is consumed by the combustion work of the engine. The amount of methanol remaining in the inlet line 8 is related to the length of the inlet line 8. The shorter the inlet line 8, the less methanol remains in the inlet line 8. This reduces methanol waste during methanol discharge and increases the methanol recovery rate.
[0047] It should be noted that the methanol supply valve 1, methanol injector 5, relief valve 10, pressure sensor 9, inert gas supply valve 2, and methanol pipeline 4 are all tightly connected. That is, when the methanol supply valve 1, methanol injector 5, relief valve 10, and inert gas supply valve 2 are all closed, the methanol supply system is essentially a sealed chamber. Alternatively, the methanol supply valve 1 can be a shut-off valve, and the relief valve 10 and inert gas supply valve 2 can be solenoid valves. Alternatively, the inert gas can be nitrogen.
[0048] When the methanol supply valve 1 is open and the inert gas valve 2 and the bleed valve 10 are closed, the methanol stored in the methanol storage device 31 enters the methanol pipeline 4 through the methanol supply valve 1 and is ejected through the methanol injector 5. When the methanol supply valve 1 and the inert gas valve 2 are closed and the bleed valve is open, the methanol remaining in the methanol pipeline 4 is discharged through the bleed valve 10 to the methanol recovery tank 12. When the methanol supply valve 1 and the bleed valve 10 are closed and the inert gas valve 2 and the methanol injector 5 are open, the methanol remaining in the inlet pipeline 8 is ejected through the methanol injector 5 to discharge the methanol in the inlet pipeline 8.
[0049] The methanol discharge method provided in embodiments of the present invention can be executed by the controller 3 of the methanol supply system provided in any of the above embodiments. By executing the methanol discharge method, the controller discharges residual methanol from the methanol supply system, thereby purging the system of residual methanol, reducing the risk of methanol leakage, and improving safety. The following embodiments specifically illustrate the methanol discharge method executed by the controller 3.
[0050] Figure 2 Schematic diagram of a methanol discharge method provided by an embodiment of the present invention. Figure 2 , the methanol release method includes:
[0051] S110: Acquire a signal for exiting the methanol mode.
[0052] Specifically, the methanol mode exit signal is a signal for the methanol supply system to stop supplying methanol. Upon receiving the methanol mode exit signal, the methanol supply system stops supplying methanol and evacuates any remaining methanol in the system. Exemplarily, the signal is triggered by an engine operator using a control button.
[0053] S120: Based on the methanol mode exit signal, the methanol supply valve and the methanol injector are closed, and the discharge valve is opened.
[0054] Specifically, upon receiving the methanol mode exit signal, the controller closes the methanol supply valve and the methanol injector. Methanol no longer flows into the methanol pipeline, and the methanol injector ceases operation. It should be noted that when the methanol supply system is operating, only the methanol supply valve and the methanol injector are open; all other valves are closed.
[0055] When the methanol supply valve and methanol injector are closed, methanol that has not been ejected by the methanol injector remains in the methanol pipeline. When the release valve is opened, the remaining methanol in the methanol pipeline is discharged through the release valve to the methanol recovery cabinet.
[0056] S130: Detect the pressure in the methanol pipeline using a pressure sensor to obtain a first pressure.
[0057] When the discharge valve is opened, the methanol in the upstream methanol pipeline flows into the methanol recovery cabinet under the action of injection pressure and gravity.
[0058] Among them, since the inlet pipeline is located at the lower end of the discharge valve, that is, at the end of the methanol supply system, when the discharge valve is opened, the methanol in the inlet pipeline cannot be discharged through the discharge pipeline.
[0059] S140: When the first pressure reaches a first preset pressure, close the relief valve and open the inert gas supply valve.
[0060] Specifically, when the first pressure reaches the first preset pressure, it indicates that the methanol in the methanol pipeline has been emptied. At this time, the controller controls the release valve to close and opens the inert gas supply valve. At this time, the inert gas in the inert gas storage device is introduced into the methanol pipeline through the inert gas supply valve to apply pressure to the methanol remaining in the inlet pipeline. The first preset pressure is the pressure in the methanol pipeline when the methanol in the methanol pipeline is emptied. Optionally, the first preset pressure can be a slightly positive pressure. It should be noted that the supply pressure of the inert gas needs to be the same as the engine methanol injection pressure.
[0061] S150: Detect the pressure in the methanol pipeline using a pressure sensor to obtain a second pressure.
[0062] Specifically, the pressure in the methanol pipeline is related to the amount of inert gas in the methanol pipeline. When there is more inert gas in the methanol pipeline, the pressure in the methanol pipeline is higher; when there is less inert gas in the methanol pipeline, the pressure in the methanol pipeline is lower.
[0063] When the inert gas supply valve is opened, the inert gas in the inert gas storage device flows into the methanol supply system, and the pressure in the methanol pipeline also rises accordingly.
[0064] S160: When the second pressure reaches a second preset pressure, start the methanol injector.
[0065] Specifically, the second preset pressure is the methanol injection pressure when the engine is in the methanol mode.
[0066] When the second pressure reaches a second preset pressure, the methanol line is filled with inert gas, which then applies pressure to the residual methanol in the inlet line. After the methanol injector is activated, the methanol in the inlet line is driven by the inert gas into the methanol injector and then ejected through the injector. When the methanol supply line is applied to an engine, the methanol ejected by the injector enters the engine cylinder and participates in combustion.
[0067] S170. After a first delay, close the methanol injector; wherein the first delay is the time required for the methanol in the inlet pipeline to be discharged.
[0068] Specifically, the first time is the time required for methanol in the inlet pipeline to be discharged, that is, the opening time of the methanol injector. After the first time is reached, all methanol in the inlet pipeline is discharged through the methanol injector. When the methanol in the inlet pipeline is discharged, the methanol injector is closed. At this time, any methanol remaining in the methanol supply system is discharged from the system.
[0069] The first time can be calculated based on the volume of the inlet line, the number of lines in the inlet line, the methanol density, and the methanol flow rate at the time the methanol mode exit signal is issued. Specifically, the residual methanol mass in the inlet line is calculated based on the volume of the inlet line, the number of lines in the inlet line, and the methanol density. The first time is then calculated based on the residual methanol mass and the methanol flow rate under the engine operating conditions at the time the methanol mode exit signal is issued. Exemplarily, the methanol injection flow rate at the time the methanol mode exit signal is issued can be calculated by comparing the real-time engine speed and boost pressure at the time the methanol mode exit signal is issued with a diagram stored in the controller that determines the methanol injection flow rate based on engine speed and boost pressure. The methanol injection flow rate at the time the methanol mode exit signal is issued is then determined using interpolation. The diagram that determines the methanol injection flow rate based on engine speed and boost pressure can be obtained through testing.
[0070] Optionally, the residual methanol is consumed by combustion after being injected into the engine, which helps to avoid environmental impact. After the methanol in the methanol supply system is emptied, the engine can be converted to diesel drive, in which case the engine operates by burning diesel.
[0071] In an embodiment of the present invention, based on a methanol mode exit signal, the methanol supply valve and the methanol injector are closed, and a bleed valve is opened. A pressure sensor is used to detect a first pressure within the methanol pipeline. When the first pressure reaches a first preset pressure, the bleed valve is closed and an inert gas supply valve is opened. A pressure sensor is used to detect a second pressure within the methanol pipeline. When the second pressure reaches a second preset pressure, the methanol injector is opened, and after a first delay, the methanol injector is closed. After the methanol in the methanol pipeline is discharged, an inert gas is introduced into the methanol pipeline to apply pressure to the methanol in the inlet pipeline. This pressure causes the methanol in the inlet pipeline to be injected into the engine through the methanol injector and consumed by combustion, thereby completely discharging any residual methanol in the methanol supply system. This reduces the risk of methanol leakage and improves safety.
[0072] Figure 3 This is a schematic diagram of another methanol discharge method provided by an embodiment of the present invention. Figure 3 After the first delay time, after closing the methanol injector, it also includes:
[0073] S180. Close the inert gas supply valve and open the discharge valve.
[0074] Specifically, when the methanol in the methanol supply system is discharged, an inert gas is introduced into the methanol supply system. Therefore, after the methanol in the methanol supply system is discharged, the methanol supply system is filled with the inert gas.
[0075] When the inert gas valve closes, the connection between the inert gas storage device and the methanol pipeline is severed, and the flow of inert gas into the methanol pipeline ceases. When the bleed valve opens, the inert gas in the methanol supply system flows through the bleed valve into the methanol recovery cabinet. Because inert gas is gaseous and methanol is liquid, the methanol recovery cabinet utilizes their phase separation to separate the two gases.
[0076] Figure 4 This is a schematic diagram of another methanol discharge method provided by an embodiment of the present invention. Based on the above embodiments, optionally, refer to Figure 4 , after closing the inert gas supply valve and opening the relief valve, it also includes:
[0077] S190: When the second pressure reaches the first preset pressure, close the relief valve.
[0078] Specifically, when the second pressure reaches the first preset pressure, it indicates that the inert gas in the methanol supply system is exhausted. When the methanol in the methanol supply system is exhausted, the controller controls the discharge valve to close.
[0079] Optionally, when the second pressure reaches the first preset pressure, the controller may further prompt the user to remind the user that the methanol in the methanol supply system has been exhausted.
[0080] An embodiment of the present invention also provides an engine. Figure 5 Schematic diagram of an engine provided by an embodiment of the present invention. Figure 5 The engine 200 includes: at least one cylinder 6 and the methanol supply system 100 provided in any of the above embodiments; each cylinder 6 is connected to a methanol injector 5 in the methanol supply system in a one-to-one correspondence. It should be noted that when the methanol supply system is discharged, the methanol remaining in the inlet pipe 8 is injected into the corresponding cylinder 6 through the methanol injector 5 under the pressure of the inert gas, and is consumed in the cylinder 6 through combustion.
[0081] The engine 200 provided in the embodiment of the present invention has the beneficial effects of the methanol supply system 100 provided in any of the above embodiments, which will not be described in detail here.
[0082] It should be understood that the various forms of the processes shown above can be used to reorder, add, or delete steps. For example, the steps described in the present invention can be performed in parallel, sequentially, or in a different order, as long as the desired results of the technical solution of the present invention can be achieved. This is not limited herein.
[0083] The above specific embodiments do not limit the scope of protection of the present invention. Those skilled in the art will appreciate that various modifications, combinations, sub-combinations, and substitutions may be made based on design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention are intended to be included within the scope of protection of the present invention.
Claims
1. A methanol discharge method, characterized in that: Applied to a methanol supply system, the methanol supply system includes: a methanol supply valve, an inlet pipeline, a methanol injector, a discharge valve, a pressure sensor, an inert gas supply valve and a methanol pipeline; the methanol discharge method includes: Get the signal to exit methanol mode; closing the methanol supply valve and the methanol injector based on the methanol mode exit signal, and opening the drain valve; detecting the pressure in the methanol pipeline based on the pressure sensor to obtain a first pressure; When the first pressure reaches a first preset pressure, closing the relief valve and opening the inert gas supply valve; detecting the pressure in the methanol pipeline based on the pressure sensor to obtain a second pressure; When the second pressure reaches a second preset pressure, opening the methanol injector; After a first delay time, the methanol injector is closed; wherein the first time is the time required for the methanol in the inlet pipeline to be discharged.
2. The methanol discharge method according to claim 1, characterized in that: After the first delay time, after closing the methanol injector, the method further includes: Close the inert gas supply valve and open the drain valve.
3. The methanol discharge method according to claim 2, characterized in that: After closing the inert gas supply valve and opening the discharge valve, the method further includes: When the second pressure reaches the first preset pressure, the relief valve is closed.
4. The methanol discharge method according to any one of claims 1 to 3, characterized in that: The specific method for obtaining the first time includes: Obtain the methanol flow rate under the engine working condition when the methanol mode exit signal is issued; Calculating the residual methanol mass in the inlet pipeline according to the pipeline volume of the inlet pipeline, the number of pipelines of the inlet pipeline, and the methanol density; The first time is calculated based on the residual methanol mass and the methanol flow rate under the engine working condition when the exit methanol mode signal is issued.
5. A methanol supply system, characterized in that: include: a controller, a methanol supply valve, a relief valve, a pressure sensor, an inert gas supply valve, a methanol line, at least one inlet line, and at least one methanol injector; The controller is respectively connected to the methanol supply valve, the methanol injector, the discharge valve, the pressure sensor and the inert gas supply valve, and the controller is used to perform the methanol discharge method according to any one of claims 1 to 4; The discharge valve and the pressure sensor are both connected to the methanol pipeline, the methanol supply valve is connected between the methanol storage device and the methanol pipeline, the inert gas supply valve is connected between the inert gas storage device and the methanol pipeline, the methanol supply valve and the inert gas supply valve are connected to the same position of the methanol pipeline, the discharge valve is also connected to the methanol recovery cabinet, the methanol injector is connected to the methanol pipeline through the inlet pipeline, and the methanol pipeline is used to transport methanol or inert gas; wherein, the methanol injector is connected to the inlet pipeline in a one-to-one correspondence.
6. The methanol supply system according to claim 5, characterized in that: The methanol supply valve is a stop valve.
7. The methanol supply system according to claim 5, characterized in that: The discharge valve is a solenoid valve; the inert gas supply valve is a solenoid valve.
8. The methanol supply system according to claim 5, characterized in that: The inert gas is nitrogen.
9. The methanol supply system according to claim 5, characterized in that: Also includes: a discharge line and at least one connecting line; The discharge pipeline is connected to the methanol pipeline through the connecting pipeline, and the discharge valve is connected between the discharge pipeline and the methanol recovery cabinet.
10. An engine, characterized in that: include: at least one gas cylinder and a methanol supply system according to any one of claims 5 to 9; Each of the cylinders is connected to each of the methanol injectors in the methanol supply system in a one-to-one correspondence.