Marine methanol fuel low-speed machine

Abstract

The utility model discloses a marine methanol fuel low-speed machine which comprises a low-speed machine body and compression ignition equipment communicated with the low-speed machine body. The compression ignition equipment comprises a compression ignition cylinder, the compression ignition cylinder is hollow, the top of the compression ignition cylinder communicates with a plurality of pre-combustion chambers, and a movement assembly used for compressing and mixing gas in the compression ignition cylinder is arranged at the bottom of the compression ignition cylinder. The hydrogen production injection device is used for preparing medium-pressure hydrogen fuel and communicates with the multiple pre-combustion chambers; the multiple ignition devices correspond to the pre-combustion chambers and extend into the corresponding pre-combustion chambers to be used for ignition operation; the multiple medium-pressure methanol ejectors are evenly distributed in the middle of the compression ignition cylinder and used for ejecting medium-pressure methanol into the compression ignition cylinder. According to the marine methanol fuel low-speed machine, hydrogen fuel is obtained through hydrogen production by methanol reforming, jet flame is formed by igniting the hydrogen fuel so as to ignite methanol gas in the cylinder body, and then 100% carbon reduction of the methanol fuel low-speed machine under the condition that green methanol fuel is used is achieved.

Description

Technical Field

[0001] The utility model relates to a marine methanol fuel low-speed engine, belonging to the technical field of engines. Background Art

[0002] Methanol fuel low-speed engine is an internal combustion engine that uses methanol as the main fuel. Its main advantages include relatively small changes to the original engine and less environmental pollution to the atmosphere.

[0003] The methanol fuel low-speed engines on the market currently mainly use high-pressure diesel cycle combustion technology solutions, which require diesel fuel that accounts for about 5% of the total energy for ignition. Under the condition of using green methanol, the engine still cannot achieve zero carbon. Single methanol fuel is difficult to compression ignite, so there is an urgent need for a low-speed engine that can be completely ignited by methanol fuel, so as to achieve 100% carbon reduction for methanol fuel low-speed engines under the condition of using green methanol fuel. Utility Model Content

[0004] The technical problem to be solved by the utility model is that the existing methanol fuel low-speed engine usually still needs a small amount of fuel for ignition and cannot achieve zero carbon emission.

[0005] In order to solve the above technical problems, the utility model provides a marine methanol fuel low-speed engine, which can achieve 100% carbon reduction when using green methanol fuel.

[0006] In order to achieve the above technical objectives and the above technical effects, this application is implemented through the following technical solutions:

[0007] A marine methanol fuel low-speed engine, comprising a low-speed engine body and a compression ignition device, wherein the compression ignition device is connected to the low-speed engine body;

[0008] The compression ignition equipment comprises:

[0009] A compression ignition cylinder, wherein the compression ignition cylinder is hollow, a plurality of pre-combustion chambers are connected to the top of the compression ignition cylinder, and a motion component for compressing and mixing the gas in the compression ignition cylinder is provided at the bottom of the compression ignition cylinder;

[0010] A hydrogen production injection device, the hydrogen production injection device is used to prepare medium-pressure hydrogen fuel and is connected to the plurality of pre-combustion chambers;

[0011] Ignition devices, a plurality of which are provided corresponding to the pre-combustion chambers and extend into the corresponding pre-combustion chambers for ignition operation;

[0012] A plurality of medium-pressure methanol injectors are provided and evenly distributed in the middle of the compression ignition cylinder for injecting medium-pressure methanol into the compression ignition cylinder.

[0013] Preferably, the hydrogen production injection device includes a methanol online reforming hydrogen production mechanism, a hydrogen fuel pump, a hydrogen fuel gas rail and a medium-pressure hydrogen fuel injector. The methanol online reforming hydrogen production mechanism includes an inlet end and an outlet end. The inlet end is connected to the external methanol liquid, the outlet end is connected to the air inlet of the hydrogen fuel pump, and the air outlet of the hydrogen fuel pump is connected to the hydrogen fuel gas rail. A plurality of medium-pressure hydrogen fuel injectors are arranged corresponding to the precombustion chamber, and a plurality of gas nozzles corresponding to the medium-pressure hydrogen fuel injectors are arranged on the hydrogen fuel gas rail.

[0014] Furthermore, the hydrogen fuel pump is a boost pump.

[0015] Preferably, a scavenging port is provided in the middle and lower part of the compression ignition cylinder, and the compression ignition cylinder is located on the outer wall at the scavenging port and is connected to the low-speed engine body.

[0016] Furthermore, the motion component includes a crankshaft, a connecting rod and a piston component. The crankshaft is rotatably disposed in the low-speed engine body, one end of the crankshaft is movably connected to the connecting rod, and the end of the connecting rod facing away from the crankshaft is movably connected to the piston rod of the piston component. The head of the piston component extends into the compression ignition cylinder and slides in a direction close to or away from the top of the compression ignition cylinder.

[0017] Preferably, the compression ignition cylinder is connected to an exhaust valve.

[0018] Preferably, the pre-combustion chamber is provided with a spray hole connected to the compression ignition cylinder.

[0019] Furthermore, the opening area of ​​the spray hole is much smaller than the cross-sectional area of ​​the compression ignition cylinder on the horizontal plane.

[0020] Preferably, the compression ignition cylinder comprises a cylinder liner and a cylinder head, the cylinder liner is hollow and has an open top, the cylinder head is detachably arranged on the top of the cylinder liner to seal the cylinder liner, and the pre-combustion chamber is arranged on the cylinder head.

[0021] Furthermore, the cylinder liner is connected to the cylinder head via through bolts.

[0022] The utility model provides a marine methanol fuel low-speed engine, which has the following advantages:

[0023] 1. When the utility model is used, medium-pressure methanol gas is injected into the compression cylinder through the medium-pressure methanol injector, and forms a premixed gas with the air in the compression cylinder under the action of the strong vortex formed by the compression of the moving component. Then, medium-pressure hydrogen is injected into the precombustion chamber connected to the compression cylinder through the hydrogen production injection device. The medium-pressure hydrogen forms a hydrogen mixture with the air in the precombustion chamber during the injection process. When the piston moves to the vicinity of the top dead center, the ignition device ignites the hydrogen mixture in the precombustion chamber, and the jet flame formed by the combustion in the precombustion chamber ignites the premixed gas formed by methanol and air to achieve combustion, thereby achieving complete carbon reduction of the methanol fuel low-speed engine under the condition of using green methanol fuel.

[0024] 2. When the utility model is used, by making the opening area of ​​the spray hole connecting the compression ignition cylinder and the pre-combustion chamber much smaller than the cross-sectional area of ​​the compression ignition cylinder in the horizontal plane, and then utilizing the extremely low density of hydrogen, when the piston moves upward in the compression stroke, hydrogen cannot escape from the pre-combustion chamber. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a simplified structural diagram of a methanol fuel low-speed engine for ships of the utility model;

[0026] In the figure:

[0027] 1- low-speed engine body; 2- compression ignition equipment; 21- compression ignition cylinder; 211- cylinder liner; 212- cylinder head; 22- hydrogen production injection device; 221- methanol online reforming hydrogen production mechanism; 222- hydrogen fuel pump; 223- hydrogen fuel rail; 224- medium-pressure hydrogen fuel injector; 23- ignition device; 24- medium-pressure methanol injector; 3- pre-combustion chamber; 4- motion assembly; 41- crankshaft; 42- connecting rod; 43- piston component; 5- scavenging port; 6- exhaust valve; 7- spray hole. DETAILED DESCRIPTION

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

[0029] Reference Figure 1 A marine methanol fuel low-speed engine comprises a low-speed engine body 1 and a compression ignition device 2. The compression ignition device 2 is connected to the low-speed engine body 1 and is used to compress and burn gas fuel to provide power for the low-speed engine as a whole.

[0030] Reference Figure 1 The compression ignition equipment 2 includes a compression ignition cylinder 21, a hydrogen production injection device 22 and an ignition device 23. The compression ignition cylinder 21 is hollow and is connected to multiple pre-combustion chambers 3 on the top. The hydrogen production injection device 22 is used to prepare medium-pressure hydrogen and pass it into multiple pre-combustion chambers 3 to form a hydrogen mixture with the air in the pre-combustion chambers 3. The ignition device 23 is installed in the pre-combustion chamber 3 and is corresponding to the pre-combustion chamber 3. A plurality of devices for igniting the hydrogen mixture in the pre-combustion chamber 3 are arranged to form a jet flame at the connection between the pre-combustion chamber 3 and the compression ignition cylinder 21. In this embodiment, the ignition device 23 is preferably a spark plug, which is a prior art and will not be described in detail.

[0031] Furthermore, the compression ignition cylinder 21 includes a cylinder liner 211 and a cylinder head 212. The cylinder liner 211 is hollow and has an open top. The cylinder head 212 is connected and sealed to the cylinder liner 211 by through bolts. The pre-combustion chamber 3 is integrally injection molded on the cylinder head 212. A sealing gasket can also be installed between the cylinder liner 211 and the cylinder head 212 to enhance the sealing. In a feasible embodiment, the cylinder liner 211 and the cylinder head 212 can be cover bodies and cylinder bodies of any shape and fit each other. In this embodiment, the cylinder body and the cylinder head 212 are preferably cylindrical.

[0032] Reference Figure 1 In a further embodiment, the hydrogen production injection device 22 includes a methanol online reforming hydrogen production mechanism 221, a hydrogen fuel pump 222, a hydrogen fuel gas rail 223 and a medium-pressure hydrogen fuel injector 224. The methanol online reforming hydrogen production mechanism 221 includes an inlet end and an outlet end, the inlet end is connected to the external methanol liquid, the outlet end is connected to the inlet of the hydrogen fuel pump 222, the outlet of the hydrogen fuel pump 222 is connected to the hydrogen fuel gas rail 223, the medium-pressure hydrogen fuel injector 224 is correspondingly installed with a plurality of medium-pressure hydrogen fuels for injecting into the precombustion chamber 3, and the hydrogen fuel gas rail 223 is integrally formed with a plurality of gas nozzles corresponding to the medium-pressure hydrogen fuel injector 224. In this embodiment, the hydrogen fuel pump 222 is an additional pump, and the methanol online reforming hydrogen production mechanism 221, the hydrogen fuel pump 222, the hydrogen fuel gas rail 223 and the medium-pressure hydrogen fuel injector 224 are all prior art and will not be described in detail.

[0033] Reference Figure 1 A marine methanol fuel low-speed engine also includes a medium-pressure methanol injector 24 and a motion component 4. The medium-pressure methanol injector 24 is installed in multiple and is evenly distributed around the circumference of the cylinder liner 211 and installed in the middle of the cylinder liner 211. The motion component 4 is installed at the bottom of the cylinder liner 211 to compress the gas in the compression ignition cylinder 21 toward the cylinder head 212. When in use, the medium-pressure methanol injector 24 injects medium-pressure methanol into the compression ignition cylinder 21. During the process of the motion component 4 compressing the gas in the cylinder liner 211, the medium-pressure methanol spray in the cylinder liner 211 and the air in the cylinder liner 211 form a premixed gas under the action of a strong vortex, and finally ignite the jet flame ejected from the pre-combustion chamber 3 to achieve combustion, thereby achieving 100% carbon reduction for the methanol fuel low-speed engine under the condition of using green methanol fuel.

[0034] Reference Figure 1 In a further embodiment, a plurality of scavenging ports 5 are provided in the circumferential direction at the middle and lower part of the cylinder liner 211, a low-speed engine body 1 is sleeved and installed on the outer wall of the compression ignition cylinder 21 at the scavenging port 5, an exhaust port is integrally formed at the top of the cylinder head 212, and an exhaust valve 6 is installed at the exhaust port.

[0035] Furthermore, the motion assembly 4 includes a crankshaft 41, a connecting rod 42 and a piston component 43. In this embodiment, the engine piston component 43 is a prior art and will not be described in detail. One end of the crankshaft 41 is rotatably mounted in the low-speed engine body 1, and the other end of the crankshaft 41 is connected to the connecting rod 42 through a crank pin. The end of the connecting rod 42 away from the crankshaft 41 is movably connected to the piston rod of the piston component 43 through a transmission shaft. The head of the piston component 43 extends into the compression ignition cylinder 21 and moves toward or away from the top of the compression ignition cylinder 21. When in use, the crankshaft 41 pulls the connecting rod 42 during rotation, and the connecting rod 42 pulls the piston component 43. The piston component 43 can only slide along the inner wall of the cylinder sleeve 211 under the restriction of the inner wall of the cylinder sleeve 211, and at the same time changes the air pressure in the cylinder sleeve 211 during the movement. The scavenging port 5 is in the lower middle part of the cylinder sleeve 211. When the piston moves downward to open the scavenging port 5, fresh air can enter the cylinder sleeve 211 from the scavenging port 5 for scavenging and then be discharged from the exhaust port, so that the cylinder sleeve 211 is filled with fresh air.

[0036] Reference Figure 1 The pre-combustion chamber 3 is integrally formed with a spray hole 7 connected to the compression ignition cylinder 21. The opening area of ​​the spray hole 7 is much smaller than the cross-sectional area of ​​the compression ignition cylinder 21 in the horizontal plane. In a feasible embodiment, the spray hole 7 can be a hole of any shape. In this embodiment, the spray hole 7 is preferably a circular hole, that is, the diameter of the spray hole 7 is much smaller than the diameter of the cylinder liner 211. Then, by utilizing the extremely low density of hydrogen and the small size of the spray hole 7, when the piston is in the upward compression stroke, hydrogen cannot escape from the pre-combustion chamber 3.

[0037] The specific combustion organization process of a marine methanol fuel low-speed engine of the utility model is as follows:

[0038] The piston moves upward, so that the cylinder sleeve 211 is filled with fresh air, and the scavenging port 5 and the exhaust valve 6 are closed at the same time. The medium-pressure methanol injector 24 installed in the middle of the cylinder sleeve 211 starts to spray medium-pressure methanol gas. The medium-pressure methanol gas forms a premixed gas with the air in the cylinder under the action of strong vortex. Methanol fuel generates hydrogen through methanol online reforming hydrogen production mechanism 221, which is pressurized by hydrogen booster pump and hydrogen fuel rail 223 and enters medium-pressure hydrogen fuel injector 224. A precombustion chamber 3 is installed on the top of the cylinder head 212. The hydrogen fuel injector and the ignition device 23 are both installed in the precombustion chamber 3. During the upward movement of the piston, the pressure in the cylinder continues to rise. The medium-pressure hydrogen fuel injector 224 sprays before the cylinder pressure reaches the injection pressure, forming a hydrogen premixed gas in the precombustion chamber 3. Due to the extremely low density of hydrogen, the small spray hole 7 of the precombustion chamber 3, and the upward movement of the piston in the compression stroke, hydrogen cannot escape from the precombustion chamber 3. When the piston moves to the vicinity of the top dead center, the ignition device 23 ignites the hydrogen mixture in the pre-combustion chamber 3, and the jet flame formed by the combustion in the pre-combustion chamber 3 ignites the pre-mixed gas formed by methanol and air, thereby achieving combustion.

[0039] The above is only a preferred embodiment of the utility model, and is not any formal or substantial limitation of the utility model. It should be pointed out that ordinary technicians in this technical field can make some improvements and supplements without departing from the utility model, and these improvements and supplements should also be regarded as the protection scope of the utility model. Any technician familiar with this profession can make some changes, modifications and equivalent changes made by using the technical content disclosed above without departing from the spirit and scope of the utility model, which are all equivalent embodiments of the utility model; at the same time, any changes, modifications and evolutions of any equivalent changes made to the above embodiments based on the essential technology of the utility model are still within the scope of the technical solution of the utility model.

Claims

1. A marine methanol fuel low-speed engine, characterized in that: It comprises a low-speed engine body (1) and a compression ignition device (2), wherein the compression ignition device (2) is connected to the low-speed engine body (1); The compression ignition device (2) comprises: A compression ignition cylinder (21), wherein the compression ignition cylinder (21) is hollow, the top of the compression ignition cylinder (21) is connected to a plurality of pre-combustion chambers (3), and the bottom of the compression ignition cylinder (21) is provided with a motion component (4) for compressing and mixing the gas in the compression ignition cylinder (21); a hydrogen production injection device (22), wherein the hydrogen production injection device (22) is used for preparing medium-pressure hydrogen fuel and is connected to the plurality of pre-combustion chambers (3); Ignition devices (23), which are arranged in plurality corresponding to the pre-combustion chambers (3) and extend into the corresponding pre-combustion chambers (3) for ignition operation; A plurality of medium-pressure methanol injectors (24) are arranged and evenly distributed in the middle of the compression ignition cylinder (21) for injecting medium-pressure methanol into the compression ignition cylinder (21).

2. A marine methanol fuel low-speed engine as claimed in claim 1, characterized in that: The hydrogen production injection device (22) comprises a methanol online reforming hydrogen production mechanism (221), a hydrogen fuel pump (222), a hydrogen fuel gas rail (223) and a medium-pressure hydrogen fuel injector (224). The methanol online reforming hydrogen production mechanism (221) comprises an inlet end and an outlet end. The inlet end is connected to an external methanol liquid, the outlet end is connected to an air inlet of the hydrogen fuel pump (222), and the air outlet of the hydrogen fuel pump (222) is connected to the hydrogen fuel gas rail (223). A plurality of medium-pressure hydrogen fuel injectors (224) are arranged corresponding to the pre-combustion chamber (3), and a plurality of gas nozzles corresponding to the medium-pressure hydrogen fuel injectors (224) are arranged on the hydrogen fuel gas rail (223).

3. A marine methanol fuel low-speed engine as claimed in claim 2, characterized in that: The hydrogen fuel pump (222) is a booster pump.

4. A marine methanol fuel low-speed engine as claimed in claim 1, characterized in that: A scavenging port (5) is provided at the middle and lower part of the compression ignition cylinder (21), and the compression ignition cylinder (21) is connected to the low-speed engine body (1) on its outer wall at the scavenging port (5).

5. A marine methanol fuel low-speed engine as claimed in claim 4, characterized in that: The motion assembly (4) comprises a crankshaft (41), a connecting rod (42) and a piston component (43); one end of the crankshaft (41) is rotated in the low-speed engine body (1); the other end of the crankshaft (41) is movably connected to the connecting rod (42); the end of the connecting rod (42) away from the crankshaft (41) is movably connected to the piston rod of the piston component (43); the head of the piston component (43) extends into the compression ignition cylinder (21) and slides in a direction close to or away from the top of the compression ignition cylinder (21).

6. A marine methanol fuel low-speed engine as claimed in claim 1, characterized in that: The compression ignition cylinder (21) is connected to an exhaust valve (6).

7. A marine methanol fuel low-speed engine as claimed in claim 1, characterized in that: The pre-combustion chamber (3) is provided with a spray hole (7) which is in communication with the compression ignition cylinder (21).

8. A marine methanol fuel low-speed engine as claimed in claim 7, characterized in that: The opening area of ​​the spray hole (7) is much smaller than the cross-sectional area of ​​the compression ignition cylinder (21) on the horizontal plane.

9. A marine methanol fuel low-speed engine as claimed in claim 1, characterized in that: The compression ignition cylinder (21) comprises a cylinder liner (211) and a cylinder head (212); the cylinder liner (211) is hollow and has an open top; the cylinder head (212) is detachably arranged on the top of the cylinder liner (211) to seal the cylinder liner (211); and the pre-combustion chamber (3) is arranged on the cylinder head (212).

10. A marine methanol fuel low-speed engine as claimed in claim 9, characterized in that: The cylinder sleeve (211) is connected to the cylinder head (212) via through bolts.

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