Diesel methanol rapid switching system and switching method based on methanol compression ignition

Abstract

The invention discloses a diesel and methanol fast switching system and method based on methanol compression ignition. The diesel and methanol fast switching system comprises a diesel low-pressure supply unit, a methanol low-pressure supply unit, a high-pressure supply unit and a supply electronic switching valve. The supply electronic switching valve is respectively connected with the diesel low-pressure supply unit, the methanol low-pressure supply unit and the high-pressure supply unit, and the high-pressure supply unit is used for being connected with a compression ignition engine; the ECU is connected with the supply electronic switching valve and used for controlling the supply electronic switching valve to conduct the diesel oil low-pressure supply unit and the high-pressure supply unit when the compression ignition engine is started so as to supply diesel oil to the compression ignition engine; after the vehicle runs at an idle speed until the water temperature of the compression ignition engine reaches a preset water temperature threshold value, the electronic supply switching valve is controlled to cut off the diesel oil low-pressure supply unit and the high-pressure supply unit, and the methanol low-pressure supply unit and the high-pressure supply unit are conducted, so that methanol is supplied to the compression ignition engine; compression ignition can be carried out on methanol without additional heating, the heat efficiency is high, and the cost is low.

Description

Technical Field

[0001] The present application relates to the technical field of new energy engines, and in particular to a diesel-methanol rapid switching system and switching method based on methanol compression ignition. Background Art

[0002] Methanol is a good low-carbon fuel that can replace gasoline and diesel for various motor vehicles or non-road applications. The extensive use of methanol can both improve comprehensive resource utilization and reduce environmental pollution. Compression ignition engines have the advantages of high torque, high power, and high thermal efficiency, but methanol is not easily ignited in compression ignition engines due to its high ignition point.

[0003] In the related technologies, the main technical solutions for realizing the combustion of methanol fuel in the engine include: Solution 1, methanol is injected into the intake duct, and then ignited by spark plug or gasoline; Solution 2, methanol is injected into the intake duct, and a preheating device is added in the intake duct to increase the intake temperature of methanol, which is suitable for compression ignition; Solution 3, an oxidation aid is added to the methanol fuel to reduce the ignition temperature of methanol and realize compression ignition; Solution 4, methanol is directly injected into the engine cylinder, and a preheating plug is arranged next to the injector to increase the temperature in the cylinder and realize methanol compression ignition.

[0004] For Scheme 1 and Scheme 2, due to the methanol intake duct injection, the overall thermal efficiency is low; for Scheme 3, the added combustion aid is expensive, and it is not very convenient to purchase and add; for Scheme 4, a large number of preheating plugs need to be arranged, resulting in high costs and the service life cannot be well guaranteed.

[0005] Therefore, how to achieve compression ignition of methanol in the engine with high thermal efficiency and low cost is a technical problem that needs to be solved urgently. Summary of the invention

[0006] The present application provides a diesel-methanol rapid switching system and switching method based on methanol compression ignition, which can realize methanol compression ignition in the engine efficiently and at low cost.

[0007] In a first aspect, an embodiment of the present application provides a diesel-methanol rapid switching system based on methanol compression ignition, and the diesel-methanol rapid switching system based on methanol compression ignition comprises:

[0008] Diesel low-pressure supply unit, methanol low-pressure supply unit, high-pressure supply unit and supply electronic switching valve;

[0009] The electronic supply switching valve is respectively connected to the diesel low-pressure supply unit, the methanol low-pressure supply unit and the high-pressure supply unit, and the high-pressure supply unit is used to be connected to the compression ignition engine;

[0010] an electronic control unit ECU, which is connected to the electronic supply switching valve and is used to control the electronic supply switching valve to conduct the diesel low-pressure supply unit and the high-pressure supply unit when the compression ignition engine is started, so as to supply diesel to the compression ignition engine; and, after the vehicle is idling and the water temperature of the compression ignition engine reaches a preset water temperature threshold, control the electronic supply switching valve to cut off the diesel low-pressure supply unit and the high-pressure supply unit, and conduct the methanol low-pressure supply unit and the high-pressure supply unit, so as to supply methanol to the compression ignition engine.

[0011] In combination with the first aspect, in one embodiment, the diesel low-pressure supply unit includes a diesel tank, a diesel filter and a diesel low-pressure pump;

[0012] The methanol low-pressure supply unit comprises a methanol tank, a methanol filter and a methanol low-pressure pump;

[0013] The supply electronic switching valve is connected to the diesel low-pressure pump and the methanol low-pressure pump respectively.

[0014] In one embodiment, the high-pressure supply unit includes a metering valve, a plunger chamber, a high-pressure pump, a common rail pipe, a rail pressure sensor, and an injector;

[0015] The supply electron switching valve is connected to the metering valve.

[0016] In one embodiment, the supply electronic switching valve includes a diesel connector, a methanol connector, an oil outlet connector, a solenoid valve, and a control rod;

[0017] The diesel connector is connected to the diesel low-pressure pump, the methanol connector is connected to the methanol low-pressure pump, and the oil outlet connector is connected to the metering valve.

[0018] In one embodiment, the electronic control unit ECU is further used for:

[0019] When the compression ignition engine is started, the solenoid valve is controlled to push the control rod to connect the diesel connector and the oil outlet connector to supply diesel to the compression ignition engine. After the vehicle is idling until the water temperature of the compression ignition engine reaches the water temperature threshold, the solenoid valve is controlled to push the control rod to cut off the diesel connector and the oil outlet connector, and connect the methanol connector and the oil outlet connector to supply methanol to the compression ignition engine.

[0020] In one embodiment, the system further comprises:

[0021] Oil return electronic switching valve;

[0022] The oil return electronic switching valve is respectively connected to the oil return passages of the diesel low-pressure supply unit, the methanol low-pressure supply unit and the high-pressure supply unit.

[0023] In one embodiment, the electronic control unit ECU is connected to the return oil electronic switching valve, and is used to control the return oil electronic switching valve to connect the diesel low-pressure supply unit and the return oil circuit when the supply electronic switching valve connects the diesel low-pressure supply unit and the high-pressure supply unit, and to control the return oil electronic switching valve to cut off the diesel low-pressure supply unit and the return oil circuit, and connect the methanol low-pressure supply unit and the return oil circuit when the supply electronic switching valve is controlled to connect the methanol low-pressure supply unit and the high-pressure supply unit.

[0024] In a second aspect, an embodiment of the present application provides a switching method implemented by a diesel-methanol fast switching system based on methanol compression ignition according to any one of the above, the method comprising:

[0025] When the compression ignition engine is started, the electronic supply switching valve is controlled by the electronic control unit ECU to conduct the diesel low-pressure supply unit and the high-pressure supply unit to supply diesel to the compression ignition engine;

[0026] After the vehicle is idling until the water temperature of the compression ignition engine reaches a preset water temperature threshold, the supply electronic switching valve is controlled to cut off the diesel low-pressure supply unit and the high-pressure supply unit, and to connect the methanol low-pressure supply unit and the high-pressure supply unit to supply methanol to the compression ignition engine.

[0027] In conjunction with the second aspect, in one implementation, the method further includes:

[0028] When the supply electronic switching valve connects the diesel low-pressure supply unit and the high-pressure supply unit, the electronic control unit ECU controls the return oil electronic switching valve to connect the diesel low-pressure supply unit and the return oil circuit. When the supply electronic switching valve is controlled to connect the methanol low-pressure supply unit and the high-pressure supply unit, the return oil electronic switching valve is controlled to cut off the diesel low-pressure supply unit and the return oil circuit, and connect the methanol low-pressure supply unit and the return oil circuit.

[0029] In one embodiment, the method further comprises:

[0030] After the electronic control unit ECU controls the supply electronic switching valve to connect the methanol low-pressure supply unit and the high-pressure supply unit, the methanol injection pulse width and supply amount of the high-pressure supply unit are adjusted according to the intake flow and speed of the compression ignition engine.

[0031] The beneficial effects brought by the technical solution provided in the embodiments of the present application include:

[0032] The embodiment of the present application provides a diesel-methanol fast switching system and switching method based on methanol compression ignition, the system comprising: a diesel low-pressure supply unit, a methanol low-pressure supply unit, a high-pressure supply unit and a supply electronic switching valve; the supply electronic switching valve is respectively connected to the diesel low-pressure supply unit, the methanol low-pressure supply unit and the high-pressure supply unit, and the high-pressure supply unit is used to be connected to the compression ignition engine; an electronic control unit ECU is connected to the supply electronic switching valve, and is used to control the supply electronic switching valve to conduct the diesel low-pressure supply unit and the high-pressure supply unit when the compression ignition engine is started, so as to supply diesel to the compression ignition engine. , after the vehicle is idling until the water temperature of the compression ignition engine reaches a preset water temperature threshold, the supply electronic switching valve is controlled to cut off the diesel low-pressure supply unit and the high-pressure supply unit, and to connect the methanol low-pressure supply unit and the high-pressure supply unit to supply methanol to the compression ignition engine. This can achieve the goal of first providing the engine with diesel for compression ignition when the engine is started, and then switching to supplying methanol when the temperature in the engine cylinder is high enough. At this time, the engine is already in a high-temperature state, and the methanol injected at high pressure is in a high-temperature environment, and can be quickly compression-ignited and ignited by the engine without additional heating, thereby solving the cold start problem of methanol, with high thermal efficiency and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a schematic diagram of the structure of the diesel-methanol rapid switching system based on methanol compression ignition in this application;

[0034] Figure 2 A schematic diagram of the structure of the electronic switching valve provided for this application;

[0035] Figure 3 This is a schematic diagram of the process of the diesel-methanol rapid switching method based on methanol compression ignition in this application;

[0036] In the figure: 1. Diesel low-pressure supply unit; 2. Methanol low-pressure supply unit; 3. High-pressure supply unit; 4. Supply electronic switching valve; 5. Compression ignition engine; 6. Electronic control unit ECU; 7. Return oil electronic switching valve; 8. Return oil circuit; 11. Diesel tank; 12. Diesel filter; 13. Diesel low-pressure pump; 21. Methanol tank; 22. Methanol filter; 23. Methanol low-pressure pump; 31. Metering valve; 32. Plunger cavity; 33 High-pressure pump; 34. Common rail pipe; 35. Rail pressure sensor; 36. Injector; 41. Diesel connector; 42. Methanol connector; 43. Oil outlet connector; 44. Solenoid valve; 45. Control lever. DETAILED DESCRIPTION

[0037] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0038] In order to make the objectives, technical solutions and advantages of the present application clearer, the implementation methods of the present application will be further described in detail below with reference to the accompanying drawings.

[0039] In a first aspect, an embodiment of the present application provides a diesel-methanol rapid switching system based on methanol compression ignition.

[0040] In one embodiment, referring to Figure 1 , Figure 1 This is the structural intention of the first embodiment of the diesel-methanol fast switching system based on methanol compression ignition of this application. Figure 1 As shown, the diesel-methanol fast switching system based on methanol compression ignition includes:

[0041] A diesel low-pressure supply unit 1, a methanol low-pressure supply unit 2, a high-pressure supply unit 3 and a supply electronic switching valve 4;

[0042] The supply electronic switching valve 4 is respectively connected to the diesel low-pressure supply unit 1, the methanol low-pressure supply unit 2 and the high-pressure supply unit 3, and the high-pressure supply unit 3 is used to be connected to the compression ignition engine 5;

[0043] The electronic control unit ECU6 is connected to the supply electronic switching valve 4 and is used to control the supply electronic switching valve 4 to conduct the diesel low-pressure supply unit 1 and the high-pressure supply unit 3 when the compression ignition engine 5 is started, so as to supply diesel to the compression ignition engine 5. After the vehicle is idling until the water temperature of the compression ignition engine 5 reaches a preset water temperature threshold, the supply electronic switching valve 4 is controlled to cut off the diesel low-pressure supply unit 1 and the high-pressure supply unit 3, and to conduct the methanol low-pressure supply unit 2 and the high-pressure supply unit 3, so as to supply methanol to the compression ignition engine 5.

[0044] It is worth noting that the diesel-methanol fast switching system based on methanol compression ignition provided in this embodiment performs a diesel-methanol switching process including: when the vehicle is powered on and the engine is started, the electronic control unit ECU6 controls the supply electronic switching valve 4 to conduct the diesel low-pressure supply unit 1 and the high-pressure supply unit 3, the diesel low-pressure supply unit 1 supplies diesel, and the high-pressure supply unit 3 performs diesel high-pressure injection, so that the diesel enters the compression ignition engine 5 for compression ignition, and the compression ignition engine 5 enters an idling state. During the idling process of the compression ignition engine 5, the compression ignition engine 5 feeds back the water temperature to the electronic control unit ECU6. When the water temperature reaches the preset water temperature threshold, the electronic control unit ECU6 powers on the supply electronic switching valve 4 to cut off the diesel path. At this time, the diesel low-pressure supply unit stops working, and the supply electronic switching valve 4 conducts the methanol low-pressure supply unit 2 and the high-pressure supply unit 3, the methanol low-pressure supply unit 2 supplies methanol, and the high-pressure supply unit 3 performs methanol high-pressure injection, so that the methanol enters the compression ignition engine 5 for compression ignition. When the water temperature of the compression ignition engine 5 reaches the preset water temperature threshold, it indicates that the compression ignition engine 5 is already in a hot engine state, and the methanol injected under high pressure is in a high temperature environment and can be compression ignited quickly.

[0045] Preferably, the supply electronic switching valve 4 in the present embodiment can be set to a normally open diesel circuit mode, in which the methanol low-pressure supply unit 2 and the high-pressure supply unit 3 are turned on except when the water temperature feedback from the compression ignition engine 5 reaches a preset water temperature threshold, and the diesel low-pressure supply unit 1 and the high-pressure supply unit 3 are kept turned on at other times.

[0046] In this embodiment, it can also be set that the compression ignition engine 5 enters the idle running state and starts to feedback the water temperature to the electronic control unit ECU6 after running for a preset time. For example, the preset time is 10 minutes, and the compression ignition engine 5 enters the idle running state and starts to feedback the water temperature to the electronic control unit ECU6 after running for 10 minutes. Because it takes a certain amount of time for the engine water temperature to rise from a low temperature when the engine is idling, setting the preset time to feedback the water temperature can avoid feeding back useless water temperature data to the ECU, thereby reducing the data processing pressure of the ECU. Among them, the water temperature threshold in this embodiment can be set according to demand. In this embodiment, it is set to the water temperature when methanol is injected into the compression ignition engine 5 and can be compression ignited.

[0047] In some optional embodiments, the diesel low-pressure supply unit 1 includes a diesel tank 11, a diesel filter 12 and a diesel low-pressure pump 13; the methanol low-pressure supply unit includes a methanol tank 21, a methanol filter 22 and a methanol low-pressure pump 23; the supply electronic switching valve 4 is respectively connected to the diesel low-pressure pump 13 and the methanol low-pressure pump 23.

[0048] In one embodiment, the high-pressure supply unit includes a metering valve 31 , a plunger chamber 32 , a high-pressure pump 33 , a common rail pipe 34 , a rail pressure sensor 35 , and an injector 36 .

[0049] When the electronic supply switching valve 4 conducts the diesel low-pressure supply unit 1 and the high-pressure supply unit 3, the diesel pumped into the electronic supply switching valve 4 by the diesel low-pressure pump 13 is injected into the compression ignition engine 5 through the metering valve 31, the plunger chamber 32, the high-pressure pump 33, the common rail pipe 34, the rail pressure sensor 35, and the injector 36.

[0050] When the supply electronic switching valve 4 connects the methanol pressure supply unit 2 and the high-pressure supply unit 3, the methanol pumped into the supply electronic switching valve 4 by the methanol low-pressure pump 23 is injected into the compression ignition engine 5 through the metering valve 31, the plunger chamber 32, the high-pressure pump 33, the common rail pipe 34, the rail pressure sensor 35, and the injector 36.

[0051] Preferably, Figure 2 The supply electronic switching valve 4 includes a diesel connector 41, a methanol connector 42, an oil outlet connector 43, a solenoid valve 44, and a control rod 45; the diesel connector 41 is connected to the diesel low-pressure pump 13, the methanol connector 42 is connected to the methanol low-pressure pump 23, and the oil outlet connector 43 is connected to the metering valve 31.

[0052] Specifically, the electronic control unit ECU6 is also used to control the solenoid valve 44 to push the control rod 45 to connect the diesel connector 41 and the oil outlet connector 43 when the compression ignition engine 5 is started. At this time, the diesel low-pressure pump 13 is also in working state. The diesel low-pressure pump 13 pumps the diesel in the diesel tank 11 into the diesel connector 41 and the oil outlet connector 43 and pumps it into the metering valve 31, and finally injects it into the compression ignition engine 15 through the high-pressure supply unit 3 for compression ignition, and the vehicle enters the idling state. After the vehicle is idling until the water temperature of the compression ignition engine 5 reaches the water temperature threshold, the solenoid valve 44 is controlled to push the control rod 45 to cut off the diesel connector 41 and the oil outlet connector 43, and connect the methanol connector 42 and the oil outlet connector 43. At this time, the diesel low-pressure oil pump 13 stops running. The methanol low-pressure pump 23 enters the working state, and the methanol low-pressure pump 23 pumps the methanol in the methanol tank 21 into the diesel connector 41 and the oil outlet connector 43 and pumps it into the metering valve 31, and finally injects it into the compression ignition engine 15 through the high-pressure supply unit 3. The methanol injected with high pressure is in a high-temperature environment and is quickly compression-ignited and ignited.

[0053] As a preferred embodiment, the electronic control unit ECU6 is also used to adjust the methanol injection pulse width and supply amount of the high-pressure supply unit 3 according to the intake flow and speed of the compression ignition engine 5 after controlling the supply electronic switching valve 4 to connect the methanol low-pressure supply unit 2 and the high-pressure supply unit 3, so as to ensure better operation of the compression ignition engine.

[0054] In one embodiment, the system further includes an oil return electronic switching valve 7 ; the oil return electronic switching valve 7 is respectively connected to the oil return circuits 8 of the diesel low-pressure supply unit 1 , the methanol low-pressure supply unit 2 and the high-pressure supply unit 3 .

[0055] Specifically, the structure of the return oil electronic switching valve 7 is similar to that of the supply electronic switching valve 4, including a diesel connector, a methanol connector and a return oil connector. The diesel connector is connected to the return oil end of the diesel low-pressure supply unit 1, the methanol connector is connected to the return oil end of the methanol low-pressure supply unit 2, and the return oil connector is connected to the return oil circuit 8 of the high-pressure supply unit 3.

[0056] In an optional embodiment, the electronic control unit ECU6 is connected to the oil return electronic switching valve 7, and is used to control the oil return electronic switching valve 7 to connect the diesel low-pressure supply unit 1 and the oil return oil circuit 8 when the supply electronic switching valve 4 connects the diesel low-pressure supply unit 1 and the high-pressure supply unit 3, so that the diesel can return to the diesel tank 11 through the oil return oil circuit 8. When the supply electronic switching valve 4 is controlled to connect the methanol low-pressure supply unit 2 and the high-pressure supply unit 3, the oil return electronic switching valve 7 is controlled to cut off the diesel low-pressure supply unit 1 and the oil return oil circuit 8, and connect the methanol low-pressure supply unit 2 and the oil return oil circuit 8, so that the methanol can return to the methanol tank 21 through the oil return oil circuit 8.

[0057] The diesel-methanol fast switching system based on methanol compression ignition provided in the embodiment of the present application first uses a diesel low-pressure supply unit for diesel supply and high-pressure injection, the engine runs at idle speed for about ten minutes, and the water temperature is fed back to the ECU at the same time. When the preset threshold is reached, the ECU will power on the electronic switching valve, and the electronic switching valve is set to the normally open diesel circuit mode. The electronic switching valve will push the valve stem to cut off the diesel circuit, and the methanol low-pressure supply oil circuit will start to quickly supply methanol. At the same time, the diesel low-pressure system stops working, and the entire supply system is switched to a methanol high-pressure supply system. Since the engine is already in a hot engine state, the methanol injected into the high-pressure is in a high-temperature environment and is quickly compressed and ignited. At the same time, the engine's intake flow, speed and other information are fed back to adjust the injection pulse width and supply amount of methanol. Since this embodiment adopts the diesel first combustion method and is based on a diesel common rail system, the cost is low, and the cold start problem of methanol is solved simultaneously, making it more widely used.

[0058] The diesel-methanol rapid switching system based on methanol compression ignition provided in the embodiment of the present application has the following beneficial effects: the system does not make major changes to the existing engine, and can relatively quickly realize the high-pressure compression ignition combustion of methanol. The system continues to use the current diesel high-pressure common rail system, and the structure is mature and reliable. The system only uses one common rail system, and the cost is much lower than that of existing dual-fuel high-pressure direct injection. The system solves the cold start problem of methanol very well, and the system has a simple structure and high feasibility. The system can realize high-pressure injection of more than 1000 bar and has high thermal efficiency.

[0059] In a second aspect, an embodiment of the present application also provides a method for rapid switching of diesel to methanol based on methanol compression ignition.

[0060] In one embodiment, referring to Figure 3 , Figure 3 This is a functional module diagram of an embodiment of a method for rapid switching between diesel and methanol based on methanol compression ignition in this application. Figure 3 As shown, the diesel-methanol rapid switch based on methanol compression ignition includes:

[0061] Step S101 , when the compression ignition engine 5 is started, the electronic control unit ECU 6 controls the supply electronic switching valve 4 to conduct the diesel low-pressure supply unit 1 and the high-pressure supply unit 3 to supply diesel to the compression ignition engine 5 .

[0062] Step S102: After the vehicle is idling until the water temperature of the compression ignition engine 5 reaches a preset water temperature threshold, the supply electronic switching valve 4 is controlled to cut off the diesel low-pressure supply unit 1 and the high-pressure supply unit 3, and to connect the methanol low-pressure supply unit 2 and the high-pressure supply unit 3, so as to supply methanol to the compression ignition engine 5.

[0063] Furthermore, in one embodiment, the method further includes:

[0064] When the electronic supply switching valve 4 is connected to the diesel low-pressure supply unit 1 and the high-pressure supply unit 3, the electronic control unit ECU6 controls the oil return electronic switching valve 7 to connect the diesel low-pressure supply unit 1 and the oil return oil circuit 8. When the electronic supply switching valve 4 is controlled to connect the methanol low-pressure supply unit 2 and the high-pressure supply unit 3, the oil return electronic switching valve 7 is controlled to cut off the diesel low-pressure supply unit 1 and the oil return oil circuit 8, and connect the methanol low-pressure supply unit 2 and the oil return oil circuit 8.

[0065] Furthermore, in one embodiment, the method further includes:

[0066] After the electronic control unit ECU6 controls the supply electronic switching valve 4 to connect the methanol low-pressure supply unit 2 and the high-pressure supply unit 3, the methanol injection pulse width and supply amount of the high-pressure supply unit 3 are adjusted according to the intake flow and speed of the compression ignition engine 5.

[0067] Among them, the implementation of the above-mentioned diesel-methanol rapid switching method based on methanol compression ignition corresponds to the steps in the above-mentioned diesel-methanol rapid switching system embodiment based on methanol compression ignition, and its implementation process will not be repeated here one by one.

[0068] It should be noted that the serial numbers of the above-mentioned embodiments of the present application are only for description and do not represent the advantages or disadvantages of the embodiments.

[0069] The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings 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 limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices. The terms "first", "second" and "third" are used to distinguish different objects, etc., and do not represent a sequence, nor do they limit "first", "second" and "third" to different types.

[0070] In the description of the embodiments of the present application, "exemplary", "for example" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary", "for example" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary", "for example" or "for example" is intended to present related concepts in a specific way.

[0071] In the description of the embodiments of the present application, unless otherwise specified, “ / ” means or, for example, A / B can mean A or B; the “and / or” in the text is merely a description of the association relationship of associated objects, indicating that three relationships may exist, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present application, “multiple” refers to two or more than two.

[0072] In some processes described in the embodiments of the present application, multiple operations or steps that appear in a specific order are included, but it should be understood that these operations or steps may not be executed in the order in which they appear in the embodiments of the present application or in parallel, and the sequence number of the operation is only used to distinguish the different operations, and the sequence number itself does not represent any execution order. In addition, these processes may include more or fewer operations, and these operations or steps may be executed in sequence or in parallel, and these operations or steps may be combined.

[0073] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus a necessary general hardware platform, and of course by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present application is essentially or the part that contributes to the prior art can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, disk, CD) as described above, and includes a number of instructions for a terminal device to execute the methods described in each embodiment of the present application.

[0074] The above are only preferred embodiments of the present application, and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A fast switching system between diesel and methanol based on methanol compression ignition. It is characterized in that The diesel-methanol rapid switching system based on methanol compression ignition comprises: a diesel low-pressure supply unit (1), a methanol low-pressure supply unit (2), a high-pressure supply unit (3) and a supply electronic switching valve (4); The electronic supply switching valve (4) is respectively connected to the diesel low-pressure supply unit (1), the methanol low-pressure supply unit (2) and the high-pressure supply unit (3), and the high-pressure supply unit (3) is used to be connected to the compression ignition engine (5); An electronic control unit ECU (6) is connected to the electronic supply switching valve (4) and is used to control the electronic supply switching valve (4) to conduct the diesel low-pressure supply unit (1) and the high-pressure supply unit (3) when the compression ignition engine (5) is started, so as to supply diesel to the compression ignition engine (5); after the vehicle is idling until the water temperature of the compression ignition engine (5) reaches a preset water temperature threshold, control the electronic supply switching valve (4) to cut off the diesel low-pressure supply unit (1) and the high-pressure supply unit (3), and conduct the methanol low-pressure supply unit (2) and the high-pressure supply unit (3) to supply methanol to the compression ignition engine (5).

2. The diesel-methanol rapid switching system based on methanol compression ignition as claimed in claim 1, Features: The diesel low-pressure supply unit (1) comprises a diesel tank (11), a diesel filter (12) and a diesel low-pressure pump (13); The methanol low-pressure supply unit comprises a methanol tank (21), a methanol filter (22) and a methanol low-pressure pump (23); The supply electronic switching valve (4) is connected to the diesel low-pressure pump (13) and the methanol low-pressure pump (23) respectively.

3. The diesel-methanol rapid switching system based on methanol compression ignition as claimed in claim 2, Features: The high-pressure supply unit (3) comprises a metering valve (31), a plunger chamber (32), a high-pressure pump (33), a common rail pipe (34), a rail pressure sensor (35), and an injector (36); The supply electron switching valve (4) is connected to the metering valve (31).

4. The diesel-methanol rapid switching system based on methanol compression ignition as claimed in claim 3, Features: The supply electronic switching valve (4) comprises a diesel connector (41), a methanol connector (42), an oil outlet connector (43), a solenoid valve (44), and a control rod (45); The diesel connector (41) is connected to the diesel low-pressure pump (13), the methanol connector (42) is connected to the methanol low-pressure pump (23), and the oil outlet connector (43) is connected to the metering valve (31).

5. The diesel-methanol rapid switching system based on methanol compression ignition as claimed in claim 4, It is characterized in that The electronic control unit ECU (6) is also used for: When the compression ignition engine (5) is started, the solenoid valve (44) is controlled to push the control rod (45) to connect the diesel connector (41) and the oil outlet connector (43) so as to supply diesel to the compression ignition engine (5). When the vehicle is idling until the water temperature of the compression ignition engine (5) reaches the water temperature threshold, the solenoid valve (44) is controlled to push the control rod (45) to cut off the diesel connector (41) and the oil outlet connector (43), and connect the methanol connector (42) and the oil outlet connector (43) so as to supply methanol to the compression ignition engine (5).

6. The diesel-methanol rapid switching system based on methanol compression ignition as claimed in claim 1, It is characterized in that The system also includes: Oil return electronic switching valve (7); The oil return electronic switching valve (7) is respectively connected to the oil return passages (8) of the diesel low-pressure supply unit (1), the methanol low-pressure supply unit (2) and the high-pressure supply unit (3).

7. The diesel-methanol rapid switching system based on methanol compression ignition as claimed in claim 6, Features: The electronic control unit ECU (6) is connected to the oil return electronic switching valve (7) and is used to control the oil return electronic switching valve (7) to connect the diesel low-pressure supply unit (1) and the oil return oil circuit (8) when the supply electronic switching valve (4) connects the diesel low-pressure supply unit (1) and the high-pressure supply unit (3); and to control the oil return electronic switching valve (7) to cut off the diesel low-pressure supply unit (1) and the oil return oil circuit (8) and connect the methanol low-pressure supply unit (2) and the oil return oil circuit (8) when the supply electronic switching valve (4) connects the methanol low-pressure supply unit (2) and the high-pressure supply unit (3).

8. A switching method implemented by the diesel-methanol fast switching system based on methanol compression ignition according to any one of claims 1 to 7, It is characterized in that The method comprises: When the compression ignition engine (5) is started, the electronic supply switching valve (4) is controlled by an electronic control unit ECU (6) to conduct the diesel low-pressure supply unit (1) and the high-pressure supply unit (3) to supply diesel to the compression ignition engine (5); After the vehicle is idling until the water temperature of the compression ignition engine (5) reaches a preset water temperature threshold, the supply electronic switching valve (4) is controlled to cut off the diesel low-pressure supply unit (1) and the high-pressure supply unit (3), and to connect the methanol low-pressure supply unit (2) and the high-pressure supply unit (3) to supply methanol to the compression ignition engine (5).

9. The method for rapid switching between diesel and methanol based on methanol compression ignition as claimed in claim 8, It is characterized in that The method further includes: When the electronic supply switching valve (4) conducts the diesel low-pressure supply unit (1) and the high-pressure supply unit (3), the electronic control unit ECU (6) controls the oil return electronic switching valve (7) to conduct the diesel low-pressure supply unit (1) and the oil return oil circuit (8); when the electronic supply switching valve (4) is controlled to conduct the methanol low-pressure supply unit (2) and the high-pressure supply unit (3), the oil return electronic switching valve (7) is controlled to cut off the diesel low-pressure supply unit (1) and the oil return oil circuit (8), and conduct the methanol low-pressure supply unit (2) and the oil return oil circuit (8).

10. The method for rapid switching between diesel and methanol based on methanol compression ignition according to claim 8, It is characterized in that The method further includes: After the electronic control unit ECU (6) controls the supply electronic switching valve (4) to connect the methanol low-pressure supply unit (2) and the high-pressure supply unit (3), the methanol injection pulse width and supply amount of the high-pressure supply unit (3) are adjusted according to the intake flow rate and rotation speed of the compression ignition engine (5).

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