Methanol fuel injection system

Abstract

The utility model belongs to the technical field of fuel injection, and particularly discloses a methanol fuel injection system which comprises a master control unit, a methanol injector connected with the master control unit, a purging control unit and a supply unit, and the supply unit supplies methanol fuel or purging gas to the methanol injector; a purge gas outlet communicated with the fuel flow channel is formed in the methanol injector, opening and closing of the purge gas outlet are controlled by the purge control valve, and the purge control unit is used for opening and closing the purge control valve; the supply unit comprises a methanol pump and a first reversing valve connected with the master control unit; two inlets of the first reversing valve are respectively connected with the purge gas storage unit and the methanol fuel storage unit; an outlet of the first reversing valve is connected with a feed port of the methanol pump, and the methanol pump is connected with the methanol ejector through a high-pressure pipeline; and a fuel discharge unit is arranged on the high-pressure pipeline. Fuel injection and purging are both controlled by the master control unit in a centralized mode, and automatic switching can be achieved only through connection reversing of the first reversing valve.

Description

Technical Field

[0001] The utility model belongs to the technical field of fuel injection, and in particular relates to a methanol fuel injection system. Background Art

[0002] Energy and environmental issues are one of the most serious problems facing the world today. Humans will consume all the fossil fuels that have been formed on the earth for hundreds of millions of years in the next few hundred years, which will also bring serious environmental pollution problems. Therefore, considering both energy and environment, countries around the world are committed to researching, developing and utilizing alternative energy sources to transition the global energy structure system to a sustainable renewable energy era. Methanol fuel can be synthesized from renewable biomass resources, carbon dioxide widely present in the atmosphere, and hydrogen produced by electrolysis or photolysis of water. Therefore, as a renewable energy source, methanol fuel is increasingly favored by everyone for its many advantages such as cleanliness, environmental protection, and strong availability. It has fully demonstrated its potential to become a future marine fuel. It can be seen that the development of a methanol fuel injection system for the application of methanol internal combustion engines is imperative.

[0003] Since methanol is toxic and can easily cause fire or explosion if leaked in large quantities into a confined environment, the methanol injection system needs to have an inert gas purge function to remove the residual fuel in the methanol injection system, facilitate engine maintenance, and better ensure safety. The purge unit generally includes a purge channel and a purge valve. After the purge valve is opened, the purge gas will enter the injector through the purge channel to purge the methanol. The purge unit and the fuel supply unit are separately set and need to be controlled separately, resulting in a more complex structure of the entire injector system. Utility Model Content

[0004] The utility model aims to provide a methanol fuel injection system to solve the problem in the prior art that a purge unit and a fuel supply unit are separately arranged and need to be controlled separately, resulting in a relatively complex structure of the entire injector system.

[0005] In order to achieve the above-mentioned purpose, the technical solution of the utility model is as follows: a methanol fuel injection system, comprising a general control unit, a methanol injector connected to the general control unit, a purge control unit and a supply unit, wherein the supply unit is used to supply methanol fuel or purge gas into the methanol injector; the methanol injector is provided with a purge gas outlet connected to the internal fuel flow channel of the methanol injector, the opening and closing of the purge gas outlet is controlled by a purge control valve, and the purge control unit is used to open and close the purge control valve; the supply unit comprises a methanol pump and a first reversing valve connected to the general control unit, the two inlets of the first reversing valve are respectively connected to the purge gas storage unit and the methanol fuel storage unit; the outlet of the first reversing valve is connected to the feed port of the methanol pump, and the discharge port of the methanol pump is connected to the feed port of the methanol injector through a high-pressure pipeline; the high-pressure pipeline is connected to a fuel discharge unit connected to the general control unit.

[0006] Further, the fuel discharge unit includes a fuel discharge valve and a first fuel recovery device, and the fuel discharge valve is connected to the general control unit.

[0007] Furthermore, the high-pressure pipeline is also connected to a safety unit, which includes a safety valve and a second fuel recovery device.

[0008] Furthermore, the high-pressure pipeline is connected to a pressure sensor connected to the general control unit.

[0009] Furthermore, the purge control unit includes a second reversing valve connected to the main control unit, and two inlets of the second reversing valve are respectively connected to the outside atmosphere and the compressed gas unit; the compressed gas of the compressed gas unit is used to open the purge control valve; and the outlet of the second reversing valve is connected to the purge control valve.

[0010] Furthermore, the compressed gas unit comprises an air compressor, and an outlet of the air compressor is connected to an inlet of the second reversing valve.

[0011] Furthermore, a pressure regulating valve is connected to the connecting pipe between the outlet of the air compressor and an inlet of the second reversing valve, and the pressure regulating valve is used to adjust the pressure of the compressed air entering the second reversing valve.

[0012] Furthermore, a pressure gauge is provided between the pressure regulating valve and the second reversing valve.

[0013] Furthermore, the purge gas outlet is connected to a mixture recovery unit, and the mixture recovery unit is used to recover a mixture of methanol and the purge gas.

[0014] Furthermore, the mixture recovery unit comprises a mixture collecting device and a one-way valve, and a one-way valve is provided on a connecting pipe between the mixture collecting device and the purge gas outlet.

[0015] The working principle of this technical solution is:

[0016] (1) Methanol fuel injection mode

[0017] When methanol fuel is injected, when the first reversing valve is in the default state, the feed port of the methanol pump is connected to the methanol fuel storage unit, and the methanol fuel enters the methanol pump through the first reversing valve. At this time, the fuel discharge valve is closed, the purge control valve of the methanol injector is connected to the outside atmosphere through the second reversing valve, the purge control valve is in a closed state, and the mixture recovery unit is disconnected from the methanol injector. The high-pressure oil channel of the methanol injector becomes a closed space, so that the methanol fuel pressure in the methanol injector can be established and gradually increased. The main control unit controls the methanol injector needle valve to open the sealing surface, and the nozzle opens to inject fuel. When the injection time of the methanol injector reaches the setting value of the main control unit, the needle valve seats to close the sealing surface, the nozzle is closed, and one injection is completed.

[0018] (2) Purge mode

[0019] When shutting down or overhauling the methanol injection system, it is necessary to first clear the residual methanol fuel in the injection system. The methanol injection system uses a purge inert gas to remove the residual methanol fuel in the system, for example, the commonly used purge gas is nitrogen. When the methanol injection system needs to be purged, the main control unit first controls the fuel discharge valve to open, empties the residual methanol in the high-pressure pipeline, and reduces the pressure in the pipeline. Then the main control unit controls the first reversing valve to switch, the methanol pump disconnects the methanol fuel passage, and connects the purge gas storage unit. At the same time, the main control unit also controls the reversing with the second reversing valve, disconnects the external atmosphere, connects the compressed gas unit, and the compressed air enters the purge control valve, so that the purge control valve is opened, and the methanol injector is connected to the mixture recovery unit, thereby the purge gas passes through the first reversing valve, the methanol pump, the high-pressure pipeline, and the methanol injector successively, and the purge gas carries the residual methanol fuel in the methanol injection system and is discharged from the purge control valve to complete the purge of the methanol injection system.

[0020] The beneficial effects of this technical solution are:

[0021] ① The injection system of the present technical solution has an automatic purge function. Both fuel injection and purge are centrally controlled by the main control unit, and only the first reversing valve needs to be connected to perform automatic switching, so the structure is simple.

[0022] ② In this technical solution, the second reversing valve can automatically switch between compressed air and the outside atmosphere to achieve the control of the opening and closing of the purge control valve on the methanol injector.

[0023] ③ In this technical solution, the residual methanol in the high-pressure pipeline is first discharged through the fuel discharge valve to reduce the pressure in the high-pressure pipeline. Then, the fuel that cannot be discharged by the fuel discharge valve is purged to remove the residual fuel to the maximum extent.

[0024] ④ In this technical solution, the methanol fuel flow channel and the purge gas flow channel are exactly the same, that is, the purge gas can cover all places in contact with the methanol fuel, and the methanol injection system can be purged without dead ends, and there is no part that cannot be purged. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 The utility model is a connection principle diagram of a methanol fuel injection system. DETAILED DESCRIPTION

[0026] The following is further described in detail through specific implementation methods:

[0027] The figure marks in the drawings of the specification include: methanol pump 1, methanol fuel storage unit 2, first reversing valve 3, purge gas storage unit 4, main control unit 5, pressure sensor 6, second fuel recovery device 7, safety valve 8, fuel discharge valve 9, first fuel recovery device 10, outside atmosphere 11, air compressor 12, pressure regulating valve 13, pressure gauge 14, second reversing valve 15, mixture collecting device 16, one-way valve 17, methanol injector 18.

[0028] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0029] The embodiment is basically as shown in the attached Figure 1As shown: A methanol fuel injection system includes a general control unit 5 (specifically an ECU controller), a methanol injector 18 connected to the general control unit 5, a purge control unit and a supply unit, wherein the supply unit is used to supply methanol fuel or purge gas to the methanol injector 18. The methanol injector 18 is provided with a purge gas outlet connected to the internal fuel flow channel of the methanol injector 18, and the opening and closing of the purge gas outlet is controlled by a purge control valve, and the purge control unit is used to open and close the purge control valve. The purge control unit includes a second reversing valve 15 (specifically an electromagnetic reversing valve) connected to the general control unit 5, and the two inlets of the second reversing valve 15 are respectively connected to the outside atmosphere 11 and the compressed gas unit. The compressed gas of the compressed gas unit is used to open the purge control valve, and the purge control valve can specifically adopt an air-open valve; the outlet of the second reversing valve 15 is connected to the purge control valve. The compressed gas unit includes an air compressor 12, and the outlet of the air compressor 12 is connected to an inlet of the second reversing valve 15. A pressure regulating valve 13 is connected to the connecting pipe between the outlet of the air compressor 12 and one inlet of the second reversing valve 15. The pressure regulating valve 13 is used to adjust the pressure of the compressed air entering the second reversing valve 15 to match the opening pressure of the purge control valve. A pressure gauge 14 is also provided between the pressure regulating valve 13 and the second reversing valve 15.

[0030] The supply unit includes a methanol pump 1 and a first reversing valve 3 (specifically an electromagnetic reversing valve) connected to a general control unit 5, wherein two inlets of the first reversing valve 3 are respectively connected to a purge gas storage unit 4 and a methanol fuel storage unit 2; an outlet of the first reversing valve 3 is connected to a feed port of the methanol pump 1, and a discharge port of the methanol pump 1 is connected to a feed port of a methanol injector 18 through a high-pressure pipeline; a fuel discharge unit connected to the general control unit 5 is connected to the high-pressure pipeline, and the fuel discharge unit includes a fuel discharge valve 9 and a first fuel recovery device 10, and the fuel discharge valve 9 is connected to the general control unit 5. A safety unit and a pressure sensor 6 are also connected to the high-pressure pipeline, and the safety unit includes a safety valve 8 and a second fuel recovery device 7. The pressure sensor 6 is connected to the general control unit 5.

[0031] The purge gas outlet is connected to a mixture recovery unit for recovering a mixture of methanol and purge gas. The mixture recovery unit comprises a mixture collection device 16 and a one-way valve 17. The one-way valve 17 is provided on the connection pipe between the mixture collection device 16 and the purge gas outlet.

[0032] The specific implementation process is as follows:

[0033] (1) Methanol fuel injection mode

[0034] When the methanol fuel is injected, when the first reversing valve 3 is in the default state, the feed port of the methanol pump 1 is connected to the methanol fuel storage unit 2, and the methanol fuel enters the methanol pump 1 through the first reversing valve 3. At this time, the fuel discharge valve 9 is closed, the purge control valve of the methanol injector 18 is connected to the outside atmosphere 11 through the second reversing valve 15, the purge control valve is in a closed state, and the mixture recovery unit is disconnected from the methanol injector 18. The high-pressure oil channel of the methanol injector 18 becomes a closed space, so that the methanol fuel pressure in the methanol injector 18 can be established and gradually increased, and the general control unit 5 controls the needle valve of the methanol injector 18 to open the sealing surface, and the nozzle opens to inject fuel. When the injection time of the methanol injector 18 reaches the setting value of the general control unit 5, the needle valve seats to close the sealing surface, the nozzle is closed, and one injection is completed.

[0035] (2) Purge mode

[0036] When shutting down or overhauling the methanol injection system, it is necessary to first clear the residual methanol fuel in the injection system. The methanol injection system uses a purge inert gas to remove the residual methanol fuel in the system, for example, the commonly used purge gas is nitrogen. When the methanol injection system needs to be purged, the general control unit 5 first controls the fuel discharge valve 9 to open, empties the residual methanol in the high-pressure pipeline, and reduces the pressure in the pipeline. Then the general control unit 5 controls the first reversing valve 3 to switch, the methanol pump 1 disconnects the methanol fuel passage, and connects the purge gas storage unit 4. At the same time, the general control unit 5 also controls the reversal with the second reversing valve 15, disconnects the external atmosphere 11, connects the compressed gas unit, and the compressed air enters the purge control valve, so that the purge control valve is opened, and the methanol injector 18 is connected to the mixture recovery unit, thereby the purge gas passes through the first reversing valve 3, the methanol pump 1, the high-pressure pipeline, and the methanol injector 18 successively, and the purge gas carries the residual methanol fuel in the methanol injection system and is discharged from the purge control valve to complete the purge of the methanol injection system.

[0037] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0038] The above is only an embodiment of the utility model. The common sense such as the known specific structure and characteristics in the scheme is not described in detail here. The ordinary technicians in the relevant field know all the common technical knowledge in the technical field of the utility model before the application date or priority date, can obtain all the existing technologies in the field, and have the ability to apply the conventional experimental means before that date. The ordinary technicians in the relevant field can improve and implement this scheme in combination with their own abilities under the enlightenment given by this application. Some typical known structures or known methods should not become obstacles for ordinary technicians in the relevant field to implement this application. It should be pointed out that for the technicians in this field, without departing from the structure of the utility model, several deformations and improvements can be made, which should also be regarded as the protection scope of the utility model, which will not affect the effect of the implementation of the utility model and the practicality of the patent. The protection scope required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to explain the content of the claims.

Claims

1. A methanol fuel injection system, characterized in that: The invention comprises a general control unit (5), a methanol injector (18) connected to the general control unit (5), a purge control unit and a supply unit, wherein the supply unit is used to supply methanol fuel or purge gas into the methanol injector (18); the methanol injector (18) is provided with a purge gas outlet communicated with an internal fuel flow channel of the methanol injector (18), the opening and closing of the purge gas outlet is controlled by a purge control valve, and the purge control unit is used to open and close the purge control valve; the supply unit comprises a methanol pump (1) and a first reversing valve (3) connected to the general control unit (5), wherein two inlets of the first reversing valve (3) are respectively connected to a purge gas storage unit (4) and a methanol fuel storage unit (2); the outlet of the first reversing valve (3) is connected to a feed port of the methanol pump (1), and the discharge port of the methanol pump (1) is connected to a feed port of the methanol injector (18) via a high-pressure pipeline; the high-pressure pipeline is connected to a fuel discharge unit connected to the general control unit (5).

2. A methanol fuel injection system according to claim 1, characterized in that: The fuel discharge unit comprises a fuel discharge valve (9) and a first fuel recovery device (10), and the fuel discharge valve (9) is connected to the general control unit (5).

3. A methanol fuel injection system according to claim 1, characterized in that: The high-pressure pipeline is also connected to a safety unit, which comprises a safety valve (8) and a second fuel recovery device (7).

4. A methanol fuel injection system according to claim 1, characterized in that: The high-pressure pipeline is connected to a pressure sensor (6) which is connected to the overall control unit (5).

5. A methanol fuel injection system according to claim 1, characterized in that: The purge control unit comprises a second reversing valve (15) connected to the main control unit (5); two inlets of the second reversing valve (15) are respectively connected to the outside atmosphere (11) and the compressed gas unit; the compressed gas of the compressed gas unit is used to open the purge control valve; and the outlet of the second reversing valve (15) is connected to the purge control valve.

6. A methanol fuel injection system according to claim 5, characterized in that: The compressed gas unit comprises an air compressor (12), the outlet of the air compressor (12) being connected to an inlet of the second reversing valve (15).

7. A methanol fuel injection system according to claim 6, characterized in that: A pressure regulating valve (13) is connected to a connecting pipe between the outlet of the air compressor (12) and an inlet of the second reversing valve (15), and the pressure regulating valve (13) is used to adjust the pressure of the compressed air entering the second reversing valve (15).

8. A methanol fuel injection system according to claim 7, characterized in that: A pressure gauge (14) is also provided between the pressure regulating valve (13) and the second reversing valve (15).

9. A methanol fuel injection system according to claim 1, characterized in that: The purge gas outlet is connected to a mixture recovery unit, and the mixture recovery unit is used to recover a mixture of methanol and the purge gas.

10. A methanol fuel injection system according to claim 9, characterized in that: The mixture recovery unit comprises a mixture collecting device (16) and a one-way valve (17), and a one-way valve (17) is provided on a connecting pipe between the mixture collecting device (16) and the purge gas outlet.

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