WO2011091571A1

WO2011091571A1 - Natural gas engine

Info

Publication number: WO2011091571A1
Application number: PCT/CN2010/001868
Authority: WO
Inventors: 肖亨琳
Original assignee: 无锡开普动力有限公司
Priority date: 2010-01-28
Filing date: 2010-11-22
Publication date: 2011-08-04
Also published as: CN101922360A

Abstract

Disclosed is a natural gas engine refitted from a diesel engine, which includes a diesel engine body, a sensor system arranged on the diesel engine body, an inlet system (3), a fuel supply system (4) and an ignition system (5); wherein a low pressure natural gas source in the fuel supply system (4) is connected to a mixer pipe (4f) by a shut-off valve (4a), a pressure regulating valve (4b), a proportional valve (4d) in order; the mixer pipe (4f) is connected to an electronic throttle (4g); the electronic throttle (4g) is communicated with a combustion chamber (2) by an inlet pipe (3d); one end of a spark plug (5c) in the ignition system (5) extends into the combustion chamber (2) and the other end is connected with an ignition coil (5a) controlled by an ignition controller; every sensor in the sensor system is connected to the ignition controller and transmits signals; the ignition controller controls the proportional valve (4d) and the electronic throttle (4g). The natural gas engine is simple to refit and meets the increasingly stringent emission requirements.

Description

Natural gas engine

The present invention is in the field of engine technology, and more particularly to a natural gas engine modified from a diesel engine.

Background technique

In the prior art, the fuel of the engine is mainly gasoline and diesel. However, with the depletion of oil resources, shortage, environmental pollution and global warming, a series of problems are becoming more and more prominent, and all countries in the world are saving energy and reducing energy. Pollutants and other factors are in the first place, and increasingly strict energy conservation and emission regulations have been formulated. At present, the fuel system and supercharging system of diesel and gasoline engines will be difficult to meet future emission regulations. In order to seek efficient and clean combustion of the engine, the fuel system must be Improvements with the booster system, such as gasoline engines need to increase the three-way catalyst; diesel engines need to use advanced electronically controlled high-pressure fuel injection technology, advanced supercharged intercooling technology, advanced combustion control technology, advanced post-processing technology, etc. Combine them and apply them to meet strict emission regulations. The application of these advanced means and devices requires a lot of manpower, material and financial resources, requires complex matching development processes, is costly, and is expensive.

Summary of the invention

The object of the present invention is to provide a natural gas engine modified from a diesel engine in view of the deficiencies in the prior art, which is simple in modification, does not consume a large amount of manpower, material resources and financial resources, and can meet the requirements of energy saving and environmental protection. , and the development cycle is shorter.

According to the technical solution provided by the present invention, the natural gas engine is modified from a diesel engine, and includes a diesel engine body. The diesel engine body is provided with a sensing system, and is characterized by further comprising an air intake system, a fuel supply system, an ignition system, and a transmission. Sense system and ignition controller ECU;

The air intake system is installed on one side of the cylinder head of the engine, the air intake system includes an air filter intake pipe and an intake pipe, and the air filter intake pipe is used to open air, and the intake pipe is connected to the combustion chamber of the engine;

The fuel supply system includes a low-pressure natural gas source, a gas shut-off valve, a pressure regulating valve, a proportional valve, a mixer tube, and an electronic throttle. The low-pressure natural gas source is connected to the gas shut-off valve, the gas shut-off valve is connected to the pressure regulating valve, and the pressure regulating valve and the proportional The valve is connected, the proportional valve is connected to one inlet of the mixer tube, the other inlet on the mixer tube is connected to the air filter inlet pipe in the intake system, the outlet of the mixer tube is connected to the electronic throttle, the electronic throttle and the intake system The intake pipes are connected;

The ignition system includes an ignition coil and a spark plug. The spark plug is mounted on the cylinder head of the engine. One end of the spark plug extends into the combustion chamber, and the other end of the spark plug is connected to the ignition coil. Below the trachea, the ignition coil is connected to the ignition controller ECU through a wire;

Each sensor in the sensing system is connected to the ignition controller ECU through a wire and transmits a signal. The ignition controller ECU is connected to the proportional valve and the electronic throttle in the fuel supply system, respectively, and transmits commands, and the proportional gas is used to control the gas to enter the mixer tube. The flow rate is controlled by electronic throttle control to control the flow of the mixture into the cylinder.

As a further improvement of the present invention, a baffle is connected between the air filter inlet pipe and the mixer pipe, and the baffle plate is provided with an arc-shaped protrusion on a surface inside the mixer pipe.

As a further improvement of the present invention, a Zener tube is connected between the intake pipe and the electronic throttle. As a further improvement of the present invention, the cylinder head is a flat-bottomed cylinder head, and a piston-shaped combustion chamber is disposed at a top of the piston in the cylinder at a center position of the spark plug.

As a further improvement of the present invention, the dimple-shaped combustion chamber is a cylindrical revolving structure. As a further improvement of the present invention, the sensing system includes a crank angle sensor, a camshaft angle sensor, a crankshaft speed sensor, an intake air temperature pressure sensor, a water temperature sensor, an oxygen sensor, an oil pressure sensor, and an oil temperature sensor.

Compared with the prior art, the invention has the advantages that:

(1) The present invention appropriately improves the cylinder head, the piston combustion chamber, the intake system, the combustion supply system, and the ignition system of the existing diesel engine, thereby making it an engine capable of burning natural gas, which can meet increasingly strict requirements. The emission requirements; and the modification is convenient, and does not require a lot of manpower, material resources and financial resources.

(2) The invention effectively increases the uniformity of the air intake distribution of each cylinder by providing a voltage stabilizing tube between the electronic throttle valve and the intake pipe, reduces the change of the air-fuel ratio of each cylinder of the engine, reduces the combustion cycle variation rate, and improves The fuel consumption and emission levels of the engine.

(3) The air intake system of the present invention is provided with a baffle before the air enters the mixer pipe, and the baffle plate can enhance the mixing of the air and the gas, and is favorable for the full combustion of the mixture.

(4) The structure of the combustion chamber of the invention is ingenious and reasonable, has good processability, and the combustion chamber is fully machined, has precise shape and volume, and can achieve the best compression combustion ratio and more precise ignition of natural gas. Time to meet the combustion requirements of natural gas engines.

(5) The combustion supply system and the ignition system of the present invention are controlled by the ignition controller ECU, and the operation state of the engine in various states can be effectively controlled.

DRAWINGS

Figure 1 is a side view of the entire machine of the present invention.

Figure 2 is a front elevational view of the entire machine of the present invention. Figure 3 is a cross-sectional view of the entire machine of the present invention.

Figure 4 is a schematic view showing the positional structure of the combustion chamber of the present invention.

Figure 5 is a top plan view of the piston of Figure 4.

Figure 6 is a schematic view of the intake system of the present invention.

Figure 7 is a schematic view of an air deflector of the present invention.

Figure 8 is a cross-sectional view of the structure of Figure 7

Figure 9 is a schematic illustration of a fuel supply system of the present invention.

Figure 10 is a schematic view of the ignition system of the present invention.

DESCRIPTION OF REFERENCE NUMERALS 1 cylinder head, 2 - combustion chamber, 3 - intake system, 3a - air filter inlet pipe, 3b a deflector, 3c - voltage regulator pipe, 3d - intake pipe, 4 fuel supply system 4a—gas shut-off valve, 4b—pressure regulating valve, 4c-air pipe, 4d—proportional valve, 4e—air pipe, 4f-mixer pipe, 4g—electronic throttle, 5-ignition system, 5a—ignition coil, 5b— High-voltage line, 5c-spark plug, 6a-crank angle sensor, 6b-camshaft angle sensor, 6c-crankshaft speed sensor, 6d-intake temperature pressure sensor, 6e-water temperature sensor, 6f-oxygen sensor, 6g-oil pressure sensor, 6h - Oil temperature sensor.

detailed description

The invention will be further described below in conjunction with the embodiments of the drawings:

As shown, the present invention is modified from a diesel engine, and the modified portion is mainly a cylinder head 1 of the engine, a piston combustion chamber 2, an intake system 3, a fuel supply system 4, and an ignition system 5; wherein, the intake system 3 Mainly composed of air filter intake pipe 3a, deflector 3b, Zener pipe 3c and intake pipe 3d; fuel supply system 4 mainly consists of low pressure natural gas source, gas shut-off valve 4a, pressure regulating valve 4b, gas pipe 4c, proportional valve 4d, The air pipe 4e, the mixer pipe 4f, and the electronic throttle 4g are composed; the ignition system 5 is mainly composed of an ignition coil 5a, a high voltage wire 5b, and a spark plug 5c.

As shown in Fig. 1 to Fig. 10, the intake system 3 is mounted on the cylinder head 1 side of the engine, the air filter intake pipe 3a in the intake system 3 is used to open the air, and the air filter intake pipe 3a is passed through the air deflector. 3b is connected to an inlet of the mixer tube 4f in the fuel supply system 4, and air entering from the air filter inlet pipe 3a enters the mixer pipe 4f through the air hole opened in the air deflector 3b; the low pressure in the fuel supply system 4 The natural gas source is connected to the gas shut-off valve 4a, the gas shut-off valve 4a is directly connected to the pressure regulating valve 4b, the pressure regulating valve 4b is connected to the proportional valve 4d through the gas pipe 4c, and the proportional valve 4d is connected to the other inlet of the mixer pipe 4f through the gas pipe 4e. The natural gas as fuel passes into the mixer tube 4f and is evenly mixed with the air. The outlet of the mixer tube 4f is connected to the electronic throttle 4g, and the electronic throttle is connected to the Zener tube 3c in the intake system 3, and the Zener tube 3c and Intake pipe 3d connected, intake pipe 3d In communication with the combustion chamber 2a of the engine, the mixed gas enters the combustion chamber 2; the spark plug 5c in the ignition system 5 is mounted on the engine cylinder head 1, and one end of the spark plug 5c projects into the combustion chamber 2, and the spark plug 5c The other end is connected to the ignition coil 5a via a high voltage line 5b, and each of the spark plugs 5c is separately connected to the ignition coil 5a; the ignition coil 5a is disposed under the intake pipe 3d, and the ignition coil 5a is connected to the ignition controller ECU through a wire; each of the sensing systems The sensor is connected to the ignition controller ECU through a wire and transmits a signal. The ignition controller ECU is connected to the proportional valve 4d and the electronic throttle 4g in the fuel supply system 4, respectively, and transmits a command to control the gas into the mixer tube 4f by a proportionally wide 4d. The flow rate is controlled by the electronic throttle 4g to control the flow rate of the mixed gas into the cylinder.

As shown in FIG. 4 and FIG. 5, the cylinder head 1 adopts a flat bottom cylinder head 1 in which a piston is mounted, and a pit-shaped combustion chamber 2 is disposed at a center of the piston top relative to the spark plug 5c. 2 is a cylindrical revolving structure with good processability. The combustion chamber 2 is fully machined, with precise shape and volume. The surface of the combustion chamber 2 is smooth and compact, and the compression ratio can be increased to 12, which can achieve natural gas. The best compression-to-burn ratio and precise ignition time can meet the combustion requirements of natural gas engines.

As shown in Fig. 6, a Zener tube 3c is connected between the mixer tube 4f and the intake pipe 3d, and the mixed gas which is sufficiently mixed in the mixer tube 4f first controls the flow rate through the electronic throttle 4g, and then enters the Zener tube 3c. The voltage regulator tube 3c is for improving the uniformity of the air intake distribution of each cylinder, reducing the change of the air-fuel ratio of each cylinder of the engine, reducing the combustion cycle variation rate, and improving the fuel consumption and emission level of the engine.

As shown in FIG. 7 to FIG. 9, the baffle plate 3b is provided with an arc-shaped projection on the surface of the mixer tube 4f. The baffle of this structure can allow the air entering the mixer tube 4f to be The natural gas as a fuel is well mixed to contribute to the full combustion of the mixture.

The working process and working principle of the invention are as follows:

When the engine is started, air enters the mixer pipe 4f via the air filter intake pipe 3a, the low-pressure natural gas enters from the gas shut-off valve 4a, the pressure is adjusted by the pressure regulating valve 4b, and then enters the mixer pipe 4f via the proportional valve 4d, air and The natural gas of the fuel is thoroughly mixed in the mixer tube 4f, and then the inlet amount is controlled to enter the Zener tube 3c via the electronic throttle 4g, and the intake pipe 3d enters the combustion chamber 2 of each cylinder of the engine; in the above process, each sensor on the engine (Includes a crank angle sensor (6a) mounted on the front end of the crankshaft, a camshaft angle sensor (6b) mounted on the gear chamber cover, a crankshaft speed sensor (6c) mounted on the flywheel housing, and a pressure regulator tube (3c) The upper intake air temperature pressure sensor (6d), the water temperature sensor (6e) mounted on the water outlet seat, the oxygen sensor (6f) mounted on the exhaust pipe, the oil pressure sensor (6g) mounted on the main oil passage of the body, and Oil temperature sensor (6h). Connected to the ignition controller ECU through wires, real-time sensor detection The condition of the engine is measured and a signal is transmitted to the ignition controller ECU. The ignition controller ECU makes a comprehensive judgment on the engine to determine the optimum intake air amount of the engine, and sends a command to the proportional valve 4d and the electronic throttle connected thereto through signal conversion. 4g, the flow rate of the natural gas entering the mixer tube 4f is controlled by the proportionally wide 4d, and the flow rate of the mixed gas entering the cylinder is controlled by the electronic throttle 4g, so that the engine has good power and discharge; the ignition coil 5a also passes the ignition controller The ECU controls the ignition controller ECU to make a comprehensive judgment on the condition of the engine based on the signals transmitted from the sensors, determine the optimum ignition advance angle of the engine, and then achieve engine ignition through the ignition coil 5a.

Claims

Claim

1. A natural gas engine modified from a diesel engine, comprising a diesel body, the diesel body being provided with a sensing system, characterized by further comprising an intake system (3), a fuel supply system (4), an ignition system (5), sensor system and ignition controller (ECU);

The intake system (3) is mounted on the engine cylinder head (1) side, and the intake system (3) includes an air filter intake pipe (3a) and an intake pipe (3d), and an air filter intake pipe (3a) is used to open the air. The intake pipe (3d) is in communication with the combustion chamber (2) of the engine;

The fuel supply system (4) includes a low pressure natural gas source, a gas shut-off valve (4a), a pressure regulating valve (4b), a proportional valve (4d), a mixer tube (4f), and an electronic throttle (4g), low pressure natural gas source and gas The shut-off valve (4a) is connected, the gas shut-off valve (4a) is connected to the pressure regulating valve (4b), the pressure regulating valve (4b) is connected to the proportional valve (4d), and the proportional valve (4d) is connected to the mixer tube (4f). Connected, the other inlet on the mixer tube (4f) is connected to the air filter inlet (3a) in the intake system (3), the outlet of the mixer tube (4f) is connected to the electronic throttle (4g), electronic throttle (4g) is connected to the Zener (3c) in the air intake system (3);

The ignition system (5) includes an ignition coil (5a) and a spark plug (5c), the spark plug (5c) is mounted on the engine cylinder head (1), one end of the spark plug (5c) extends into the combustion chamber (2), and the spark plug (5c) The other end is connected to the ignition coil (5a), the ignition coil (5a) is disposed under the intake pipe (3d), and the ignition coil (5a) is connected to the ignition controller (ECU) through a wire;

The sensor in the sensor system is connected to the ignition controller (ECU) through a wire and transmits a signal. The ignition controller (ECU) is connected to the proportional valve (4d) and the electronic throttle (4g) in the fuel supply system (4), respectively. Command, control the flow of gas into the mixer tube (4f) through the proportional valve (4d), and control the flow of the mixture into the cylinder through the electronic throttle (4g).

2. The natural gas engine according to claim 1, further characterized in that: a baffle (3b) is connected between the air filter intake pipe (3a) and the mixer pipe (4f), and the deflector (3b) An arc-shaped projection is provided on the surface of the mixer tube (4f).

A natural gas engine according to claim 1, further characterized in that a Zener (3c) is connected between said intake pipe (3d) and said electronic throttle (4g).

A natural gas engine according to claim 1, further characterized in that said cylinder head (1) employs a flat bottom cylinder head (1), and a piston bottom portion of the cylinder is provided with a concave shape at a center position of the spark plug (5c). Combustion chamber (2).

5. The natural gas engine of claim 4 further characterized by: said pit-shaped The combustion chamber (2) is a cylindrical rotor structure.

6. The natural gas engine according to claim 1, further comprising: a crank angle sensor (6a) mounted at a front end of the crankshaft, a camshaft angle sensor (6b) mounted on the gear chamber cover, A crankshaft speed sensor (6c) mounted on the flywheel housing, an intake air temperature pressure sensor (6d) mounted on the Zener tube (3c), a water temperature sensor (6e) mounted on the water outlet seat, and mounted on the exhaust pipe The oxygen sensor (6f), the oil pressure sensor (6g) installed on the main oil passage of the body and the oil temperature sensor (6h).