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 device further comprises a hydrogen inlet system and an electric control system, the hydrogen inlet system comprises a hydrogen cylinder, a gas conveying pipe and an electronic injection valve, the hydrogen cylinder is communicated with the gas inlet channel through the gas conveying pipe, the electronic injection valve is arranged on the gas conveying pipe, and the electric control system comprises a control unit, an electronic accelerator and a crankshaft position sensor. The control unit is electrically connected with the electronic injection valve, the electronic accelerator and the crankshaft position sensor. 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 60%; 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 generated by 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 after hydrogen 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 knock; ④ the ignition limit of hydrogen is wide, and the high and low concentration mixed gas 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 occurrence of knock, 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 gas bottle, a gas pipe and an electronic injection valve, the hydrogen gas bottle is communicated with the intake port through the gas pipe, and the electronic injection valve is arranged on the gas pipe, the electronic control system comprises a control unit, an electronic throttle and a crankshaft position sensor, and the control unit is electrically connected with the electronic injection valve, the electronic throttle and the crankshaft position sensor.

[0009] Preferably, the sensor bracket is fixedly mounted on the machine body, the crankshaft position sensor is fixedly mounted on the sensor bracket, and the flywheel is mounted on the machine body by rotating the crankshaft; a plurality of sensor sensing holes are evenly distributed on the outer circumference of the flywheel, and the axis of the crankshaft position sensor overlaps with the center line of the sensor sensing hole.

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

[0011] Preferably, a gas delivery valve is installed on the gas delivery pipe near the hydrogen cylinder.

[0012] Preferably, the high-pressure oil pipe is connected to the combustion chamber via an injector.

[0013] The beneficial effects of this utility model are:

[0014] This invention improves the structure of the piston recess to accommodate hydrogen fuel, and replaces the traditional simple fuel injection system with an electronically controlled jet injection system and a fuel injection system. It can ensure timely and quantitative hydrogen injection, has good economic efficiency, and the hydrogen substitution rate can reach about 60%. It greatly reduces pollutant emissions and maintains low fuel consumption. Attached Figure Description

[0015] The accompanying drawings are provided to further illustrate the present invention and form part of the specification. They are used together with the embodiments of the present invention to explain the present invention, but do not constitute a limitation thereof. In the drawings:

[0016] Figure 1 This is a schematic diagram of the structure of a hydrogen fuel cell single-cylinder engine according to an embodiment of the present invention;

[0017] Figure 2 The diagram shows the piston structure; 2a is the existing piston structure, and 2b is the piston structure of the present invention.

[0018] Figure 3 This is a schematic diagram of the external mounting structure of an embodiment of the present utility model;

[0019] Figure 4 This is a schematic diagram of the installation of the crankshaft position sensor according to an embodiment of the present invention;

[0020] In the figure: 1, control unit, 2, wiring harness, 3, electronic throttle, 4, mechanical throttle, 5, hydrogen cylinder, 6, gas delivery valve, 7, gas delivery pipe, 8, electronic injection valve, 9, intake pipe, 10, crankshaft position sensor, 11, sensor support, 12, flywheel, 13, crankshaft, 14, sensor sensing hole, 15, engine body, 16, piston, 17, piston recess, 18, intake port, 19, cylinder sleeve, 20, intake valve, 21, fuel injector, 22, exhaust valve, 23, exhaust port, 24, high-pressure oil pipe, 25, fuel injection pump, 26, camshaft. DETAILED DESCRIPTION

[0021] The technical solutions of the utility model will be described clearly and completely in connection with the drawings. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments.

[0022] As Figures 1-4 shown, a hydrogen fuel single-cylinder engine includes a cylinder sleeve 19, a piston 16 and a piston recess 17. The piston recess 17 is a shallow basin structure, and the piston recess 17 and the compression clearance form a combustion chamber together. Meanwhile, the embodiment of the utility model 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 5, a gas delivery valve 6, an electronic injection valve 8 and a gas delivery pipe 7, and the hydrogen intake system provides hydrogen fuel for the engine. The electronic control system includes a control unit 1, an electronic throttle 3 and a crankshaft position sensor 10, and the electronic control system is used to accurately control the hydrogen fuel into the combustion chamber of the engine and fully burn.

[0023] The compression ratio of the existing single-cylinder diesel engine is 17:1. The greater the compression ratio, the higher the power, the lower the exhaust temperature, and the easier the ignition. However, a too high compression ratio can easily cause abnormal combustion such as hydrogen fuel engine knock and knocking. Therefore, the determination of the engine compression ratio is particularly important. Through experiments, the embodiment of the utility model determines that the engine compression ratio of the single-cylinder dual-fuel diesel engine is 10:1, which is more appropriate. Therefore, the piston recess 17 of the existing single-cylinder diesel engine is improved from the "ω" type to the shallow basin structure.

[0024] The hydrogen cylinder 5 is communicated with the air inlet channel 18 through a gas delivery pipe 7, the gas delivery pipe 7 is respectively provided with a gas delivery valve 6 and an electronic injection valve 8, the gas delivery valve 6 is close to the hydrogen cylinder 5, the electronic injection valve 8 is electrically connected with the control unit 1 through a wire harness 2, and the control unit 1 is also electrically connected with an electronic throttle 3 and a crankshaft position sensor 10. The electronic throttle 3 is fixedly installed on the engine body 15 through bolts and is connected with the mechanical throttle 4 through a connecting rod to realize linkage. One end of an air inlet pipe 9 is communicated with the atmosphere, the other end of the air inlet pipe 9 is communicated with the air inlet channel 18, one end of a high-pressure oil pipe 24 is connected with an oil injection pump 25, the mechanical throttle 4 is used for controlling the oil injection pump 25, the oil injection pump 25 is in contact with a camshaft 26, and the rotation of the camshaft 26 is converted into the linear motion of the oil injection pump 25, and the other end of the high-pressure oil pipe 24 is communicated with a combustion chamber through an oil sprayer 21. An air inlet valve 20 and an air outlet valve 22 are respectively communicated with the combustion chamber through the air inlet channel 18 and an air outlet channel 23, the air inlet valve 20 is opened and the air outlet valve 22 is closed during air intake, and the air inlet channel 18 is communicated with the combustion chamber. The air outlet valve 22 is opened and the air inlet valve 20 is closed during air exhaust, and the air outlet channel 23 is communicated with the combustion chamber.

[0025] The sensor support 11 is fixedly installed on the upper left portion of the engine body 15, the crankshaft position sensor 10 is fixedly installed on the sensor support 11 through bolts, and the flywheel 12 is rotatably installed on the engine body 15 through the crankshaft 13.

[0026] The hydrogen fuel single-cylinder engine provided by the embodiment of the utility model has the advantages that the hydrogen fuel single-cylinder engine is provided with the hydrogen cylinder, the hydrogen cylinder is communicated with the air inlet channel through the gas delivery pipe, the gas delivery pipe is respectively provided with the gas delivery valve and the electronic injection valve, the electronic injection valve is electrically connected with the control unit through the wire harness, the control unit is also electrically connected with the electronic throttle and the crankshaft position sensor, the electronic throttle is fixedly installed on the engine body through bolts and is connected with the mechanical throttle through the connecting rod to realize linkage, one end of the air inlet pipe is communicated with the atmosphere, the other end of the air inlet pipe is communicated with the air inlet channel, one end of the high-pressure oil pipe is connected with the oil injection pump, the mechanical throttle is used for controlling the oil injection pump, the oil injection pump is in contact with the camshaft, the rotation of the camshaft is converted into the linear motion of the oil injection pump, and the other end of the high-pressure oil pipe is communicated with the combustion chamber through the oil sprayer.

[0027] In specific work, the power is turned on, the whole electric control jet system is powered on, the electronic control unit 1 starts to work, and the jet action of the electric injection valve 8 is controlled according to the signal collected by the crankshaft position sensor 10; at the same time, the starter drives the flywheel 12 to rotate, and the camshaft 26 is driven to rotate, so that the oil pump 25 reciprocates, the oil pump 25 generates high-pressure diesel oil, the diesel oil is delivered to the oil injector 21 through the high-pressure oil pipe 24, and the oil injector 21 sprays the diesel oil in the combustion chamber. At this time, the high-temperature and high-pressure air generated in the piston concave pit 17 is ignited by the piston 16, and the hydrogen just sprayed is ignited at the same time, and the engine is started. The signal of the crankshaft position sensor 10 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 speed is kept at 700-800 r / min; the control throttle pull wire drives the electronic throttle 3 and the mechanical throttle 4, and the hydrogen fuel single-cylinder engine enters the normal operation state, when the load or speed is changed, the control unit 1 controls the opening time of the electric injection valve 8 according to the internal program combined with the signals transmitted by the electronic throttle 3 and the crankshaft position sensor 10, so as to increase or decrease the gas supply pulse width in real time, calculate the best gas supply amount, the best ignition timing and the like of the hydrogen fuel single-cylinder engine under the working condition, and accurately control the jet timing, the jet amount and the jet time; the power is turned off, the throttle (the electronic throttle 3 and the mechanical throttle 4) 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 embodiments 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 should be noted that: the above embodiments are only specific embodiments of the utility model, which are used to illustrate the technical solutions of the utility model, but not to limit it, and the protection scope of the utility model is not limited to this. Those skilled in the art should understand that: any person skilled in the art can modify or easily think of changes to the technical solutions recorded in the foregoing embodiments within the technical range disclosed by the utility model, or make equivalent replacement to part of the technical features; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the utility model, and all should be covered in the protection scope of the utility model.

Claims

1. A hydrogen-fueled single-cylinder engine comprising a piston (16) and a piston recess (17) at the end of the piston (16), characterized by, The piston recess (17) is a shallow basin structure; further comprising a hydrogen gas inlet system and an electric control system, the hydrogen gas inlet system comprising a hydrogen gas cylinder (5), a gas conveying pipe (7) and an electric injection valve (8), the hydrogen gas cylinder (5) being communicated with an air inlet channel (18) through the gas conveying pipe (7), the electric injection valve (8) being arranged on the gas conveying pipe (7), the electric control system comprising a control unit (1), an electronic throttle (3) and a crankshaft position sensor (10), the control unit (1) being electrically connected with the electric injection valve (8), the electronic throttle (3) and the crankshaft position sensor (10) respectively.

2. A hydrogen-fueled single cylinder engine according to claim 1, wherein The sensor support (11) is fixedly installed on the machine body (15), the crankshaft position sensor (10) is fixedly installed on the sensor support (11), and the flywheel (12) is rotatably installed on the machine body (15) through the crankshaft (13); a plurality of sensor sensing holes (14) are uniformly arranged on the outer circumference of the flywheel (12), and the axis of the crankshaft position sensor (10) overlaps the center line of the sensor sensing hole (14).

3. A hydrogen-fueled single cylinder engine according to claim 2, wherein The gap between the front end surface of the crankshaft position sensor (10) and the outer circumferential surface of the flywheel (12) is 1.5-2.5mm.

4. The hydrogen-fueled single cylinder engine according to claim 1, wherein The gas conveying pipe (7) is provided with a gas conveying valve (6) near the hydrogen gas cylinder (5).

5. The hydrogen-fueled single cylinder engine according to claim 1, wherein The high-pressure oil pipe (24) is communicated with the combustion chamber through the oil injector (21).

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