Hydrogen fuel single-cylinder engine

Abstract

The utility model belongs to the technical field of diesel engines, and relates to a hydrogen fuel single-cylinder engine which comprises a piston and a piston pit located at the end of the piston, and the piston pit is of a shallow-basin-shaped structure. The system further comprises a hydrogen inlet system and an electric control system, the hydrogen inlet system comprises a hydrogen sprayer, a hydrogen cylinder, a gas delivery pipe and a pressure increasing valve, the electric control system comprises a control unit, an electronic accelerator and a crankshaft position sensor, the hydrogen cylinder is communicated with the hydrogen sprayer through the gas delivery pipe, the hydrogen sprayer is communicated with the combustion chamber, and the pressure increasing valve is arranged on the gas delivery pipe. And the control unit is electrically connected with the hydrogen sprayer, the electronic throttle and the crankshaft position sensor respectively. The structure of the piston pit is improved, the electronic control gas injection system and the fuel oil injection system are adopted to replace a traditional pure fuel oil injection system, timing and quantification of hydrogen gas injection can be guaranteed, good economical efficiency is achieved, and the hydrogen gas replacement rate can reach about 90%; pollutant emission is greatly reduced, and low oil consumption is kept.

Description

TECHNICAL FIELD

[0001] The utility model belongs to diesel engine technical field, concretely relates to a hydrogen fuel single cylinder engine. BACKGROUND

[0002] The current single cylinder diesel engine all adopts pure diesel as fuel, and the single cylinder diesel engine mainly has the following technical defects: high oil consumption, low efficiency, poor economy, high particulate emission pollutants polluting the environment, slow low-speed acceleration, delayed fuel combustion increasing smoke, and slow large torque increase.

[0003] Hydrogen as clean energy has been widely used, and hydrogen has high economic performance and good emission performance, and is now widely used as fuel in engines. The diesel used in the single cylinder diesel engine has great difference in physical and chemical properties from hydrogen fuel, and the physical and chemical properties of hydrogen and diesel are shown in the following table:

[0004] Property Hydrogen Diesel Density / (kg / m3) 0.09 830 Ignition point / ℃ 585 258 Ignition limit / % 4-75 6-6.5 Theoretical air-fuel ratio 34.3 14.3 Low heat value / (MJ / kg) 119.9 42.6-42.9

[0005] From the above table, the main differences between the physical and chemical properties of hydrogen and diesel include: ① the density of hydrogen is lower than that of diesel, the heat value is smaller, and the power of the engine of the same displacement is smaller; ② the ignition temperature of hydrogen is high, and it cannot be compressed and ignited like diesel, and it needs to be ignited or ignited if it is to be burned; ③ the temperature of hydrogen after combustion is high, the propagation speed is fast, the high temperature duration is short, and the high concentration hydrogen gas in the effective space is easy to cause the phenomenon of deflagration; ④ the ignition limit of hydrogen is wide, and the mixed gas of high and low concentration is easy to burn, and early combustion is easy to cause backfire.

[0006] In summary, according to the physical and chemical properties of hydrogen, when developing an engine using hydrogen as fuel, the structure of the engine needs to be improved according to its characteristics to avoid the phenomena of deflagration, abnormal sound and backfire. SUMMARY

[0007] In order to solve the above technical problems, the utility model provides a hydrogen fuel single cylinder engine. The technical scheme adopted by the utility model is as follows:

[0008] A hydrogen fuel single cylinder engine, comprising a piston and a piston pit at the end of the piston, the piston pit is a shallow basin structure, further comprising a hydrogen gas intake system and an electronic control system, the hydrogen gas intake system comprises a hydrogen injector, a hydrogen cylinder, a gas pipe and a booster valve, the electronic control system comprises a control unit, an electronic throttle and a crankshaft position sensor, the hydrogen cylinder is communicated with the hydrogen injector through the gas pipe, the hydrogen injector is communicated with the combustion chamber, the booster valve is arranged on the gas pipe, and the control unit is electrically connected with the hydrogen injector, the electronic throttle and the crankshaft position sensor.

[0009] The crankshaft position sensor is fixedly installed on the sensor support, and the flywheel is rotatably installed on the machine body through the crankshaft.

[0010] Preferably, the gap between the front end surface of the crankshaft position sensor and the outer circumferential surface of the flywheel is 1.5-2.5 mm.

[0011] Preferably, the high-pressure oil pipe is communicated with the combustion chamber through the oil sprayer.

[0012] The hydrogen fuel single-cylinder engine has the advantages that:

[0013] The hydrogen fuel single-cylinder engine has the advantages that: BRIEF DESCRIPTION OF DRAWINGS

[0014] The accompanying drawings are included to provide a further understanding of the present application, and are incorporated in and constitute a part of this specification, illustrate embodiments of the present application and serve to explain the present application, and do not constitute a limitation of the present application. In the drawings:

[0015] Figure 1 It is a structure schematic view of the hydrogen fuel single-cylinder engine of the embodiment of the present application;

[0016] Figure 2 It is a piston structure schematic view, wherein part a is an existing piston structure, and part b is the piston structure of the embodiment of the present application;

[0017] Figure 3 It is an external installation structure schematic view of the embodiment of the present application;

[0018] Figure 4 It is an installation schematic view of the crankshaft position sensor of the embodiment of the present application;

[0019] In the drawings: 1, control unit, 2, crankshaft position sensor, 3, electronic throttle, 4, wire harness, 5, hydrogen sprayer, 6, intake valve, 7, intake port, 8, piston pit, 9, piston, 10, cylinder sleeve, 11, exhaust port, 12, camshaft, 13, oil injection pump, 14, high-pressure oil pipe, 15, exhaust valve, 16, oil sprayer, 17, gas conveying pipe, 18, pressure increasing valve, 19, hydrogen cylinder, 20, mechanical throttle, 21, sensor support, 22, flywheel, 23, crankshaft, 24, sensor sensing hole, 25, machine body. DETAILED DESCRIPTION

[0020] The technical solution of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of this utility model, but not all embodiments.

[0021] like Figures 1-4 As shown, a hydrogen fuel cell single-cylinder engine includes a cylinder liner 10, a piston 9, and a piston recess 8. The piston recess 8 has a shallow basin-shaped structure, and the piston recess 8, together with the compression clearance, forms a combustion chamber. Furthermore, this embodiment of the invention adds a hydrogen intake system and an electronic control system to the existing single-cylinder diesel engine. The hydrogen intake system includes a hydrogen cylinder 19, a booster valve 18, a hydrogen injector 5, and a gas supply pipe 17, which provides hydrogen fuel to the engine. The electronic control system includes a control unit 1, an electronic throttle 3, and a crankshaft position sensor 2. The electronic control system is used to precisely control the entry of hydrogen fuel into the engine's combustion chamber and ensure its complete combustion.

[0022] The existing single-cylinder diesel engine has a compression ratio of 17:1. A higher compression ratio results in higher power, lower exhaust temperature, and easier ignition. However, an excessively high compression ratio can easily cause abnormal combustion in hydrogen fuel cell engines, such as knocking and slapping. Therefore, determining the engine compression ratio is crucial. This invention, through experiments, determined that a compression ratio of 10:1 is more suitable for a hydrogen fuel cell single-cylinder engine. Therefore, the piston recess 17 of the existing single-cylinder diesel engine is improved from an "ω" shape to a shallow basin shape.

[0023] The hydrogen cylinder 19 is connected to the inlet of the hydrogen injector 5 via a gas supply pipe 17, and the outlet of the hydrogen injector 5 is connected to the combustion chamber. A pressure boosting valve 18 is installed on the gas supply pipe 17 to provide the required pressure to the hydrogen injector 5. The hydrogen injector 5 is electrically connected to the control unit 1 via a wiring harness 4. The control unit 1 is also electrically connected to the electronic throttle 3 and the crankshaft position sensor 2. The electronic throttle 3 is fixed to the engine block 25 with bolts and is linked to the mechanical throttle 20 via a connecting rod. One end of the high-pressure fuel line 14 is connected to the fuel injection pump 13. The mechanical throttle 20 is used to control the fuel injection pump 13. The fuel injection pump 13 contacts the camshaft 12, converting the rotation of the camshaft 12 into the linear motion of the fuel injection pump 13. The other end of the high-pressure fuel line 14 is connected to the combustion chamber via the fuel injector 16. Intake valve 6 and exhaust valve 15 pass through intake passage 7 and exhaust passage 11 respectively and are connected to the combustion chamber. During intake, intake valve 6 is open and exhaust valve 15 is closed, and intake passage 7 is connected to the combustion chamber. During exhaust, exhaust valve 15 is open and intake valve 6 is closed, and exhaust passage 11 is connected to the combustion chamber.

[0024] The sensor support 21 is fixedly installed on the upper left part of the machine body 25, the crankshaft position sensor 2 is fixedly installed on the sensor support 21 through bolts, and the flywheel 22 is rotatably installed on the machine body 25 through the crankshaft 23; a plurality of sensor sensing holes 24 are uniformly arranged on the outer circumference of the flywheel 22, and the axis of the crankshaft position sensor 2 overlaps the center line of the sensor sensing hole 24; and the gap between the front end surface of the crankshaft position sensor 2 and the outer circumferential surface of the flywheel 22 is 1.5-2.5 mm.

[0025] The embodiment of the utility model discloses through reasonable reduction compression ratio, proper reduction temperature in combustion chamber, and through the electric control control system accurate control hydrogen fuel admission and admission time measure such as quantity in combustion chamber, avoided hydrogen fuel to appear deflagration, abnormal sound and backfire phenomenon.

[0026] The working principle of the hydrogen fuel single-cylinder engine provided by the embodiment of the utility model is as follows:

[0027] When working, the power is turned on, the entire electric control jet system is powered on, the electronic control unit 1 starts to work, and the jet action of the hydrogen injector 5 is controlled according to the signal collected by the crankshaft position sensor 2; at the same time, the starter drives the flywheel 22 to rotate, and the camshaft 12 is driven to rotate, so that the oil pump 13 reciprocates, the oil pump 13 generates high-pressure diesel oil, the diesel oil is delivered to the oil injector 16 through the high-pressure oil pipe 14, and the oil injector 16 sprays the diesel oil in the combustion chamber. At this time, the high-pressure and high-temperature air generated in the piston recess 8 is ignited by the diesel oil compressed by the piston 9 and simultaneously ignites the hydrogen just sprayed, and the hydrogen fuel single-cylinder engine starts. The signal of the crankshaft position sensor 2 is continuously transmitted to the control unit 1, and the hydrogen fuel single-cylinder engine enters the idle speed operation in combination with the inherent program recorded in the control unit 1, and the rotating speed is kept at 700-800 r / min; the control throttle pull wire drives the electronic throttle 3 and the mechanical throttle 20, and the hydrogen fuel single-cylinder engine enters the normal operation state, when the load or rotating speed changes, the control unit 1 controls the opening time of the hydrogen injector 5 according to the internal program and the signals transmitted by the electronic throttle 3 and the crankshaft position sensor 2, so as to increase or decrease the gas supply pulse width in real time, calculate the optimal gas supply amount, optimal ignition timing and the like of the hydrogen fuel single-cylinder engine under the working condition, and accurately control the jet timing, jet amount and jet time; the power is turned off, the throttle (the electronic throttle 3 and the mechanical throttle 20) is loosened, the electric control jet system is powered off, the sensors and the control unit 1 stop working, the jet stops, the oil injection stops, and the hydrogen fuel single-cylinder engine stops.

[0028] In the embodiment of the utility model, the technical features not described in detail are prior art or conventional technical means, which will not be described here.

[0029] Finally, it needs to be explained that: the above examples, only for the specific embodiments of the present application, to illustrate the technical scheme of the present application, and not limited to it, the protection scope of the present application is not limited to this. Those skilled in the art should understand: any familiar with the technical field of the technical personnel in the technical range disclosed by the present application, it can be modified or easily thought of changes to the technical solutions recorded in the foregoing examples, or part of the technical features of the equivalent replacement; and these modifications, changes or replacement, without the essence of the corresponding technical scheme deviate from the spirit and scope of the present application embodiment technical scheme, all should be covered in the protection scope of the present application.

Claims

1. A hydrogen fuel single cylinder engine comprising a piston (9) and a piston pocket (8) at the end of the piston (9), characterized in that, The piston recess (8) is a shallow basin structure; it also comprises a hydrogen gas inlet system and an electric control system, the hydrogen gas inlet system comprises a hydrogen injector (5), a hydrogen cylinder (19), a gas conveying pipe (17) and a booster valve (18), the electric control system comprises a control unit (1), an electronic throttle (3) and a crankshaft position sensor (2), the hydrogen cylinder (19) is communicated with the hydrogen injector (5) through the gas conveying pipe (17), the hydrogen injector (5) is communicated with the combustion chamber, the booster valve (18) is arranged on the gas conveying pipe (17), and the control unit (1) is electrically connected with the hydrogen injector (5), the electronic throttle (3) and the crankshaft position sensor (2) respectively.

2. A hydrogen-fueled single cylinder engine according to claim 1, wherein The sensor support (21) is fixedly installed on the machine body (25), the crankshaft position sensor (2) is fixedly installed on the sensor support (21), and the flywheel (22) is rotatably installed on the machine body (25) through the crankshaft (23); a plurality of sensor sensing holes (24) are uniformly arranged on the outer circumference of the flywheel (22), and the axis of the crankshaft position sensor (2) overlaps the center line of the sensor sensing hole (24).

3. A hydrogen-fueled single cylinder engine according to claim 2, wherein The gap between the front end face of the crankshaft position sensor (2) and the outer circumferential face of the flywheel (22) is 1.5-2.5 mm.

4. The hydrogen-fueled single cylinder engine according to claim 1, wherein The high-pressure oil pipe (14) is communicated with the combustion chamber through the oil injector (16).

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