CN1506565A - Ultra-low emission methanol fueled engine - Google Patents

Abstract

An ultra-low-emission methanol fuel engine, consisting of an engine, a methanol tank, a catalytic converter with a heating device, and an electronic control unit; the methanol tank is connected to the engine through an electronically controlled medium-pressure common rail fuel injection device; the methanol tank is connected to the engine through a fuel delivery pump The flow control valve is connected to the reactor in the catalytic converter installed on the engine exhaust pipe, and the catalytic converter is connected to the dimethyl ether solenoid valve installed on the intake manifold through the pressure vessel; the engine exhaust pipe is connected to the EGR valve Connection, the EGR valve is connected with the intake pipe; the input end of the electronic control unit receives various signals output by the engine, and the output end is connected with the flow control valve, dimethyl ether solenoid valve, methanol electronically controlled injector, glow plug, EGR valve and reaction connected to the electric heating device in the appliance. The advantages of the present invention are: 1. Reduce the emission of particulates; 2. No throttling loss and high thermal efficiency; 3. Reduce the emission of nitrogen oxides (NOx). 4. Save a lot of oil resources.

Description

Ultra-low emission methanol fuel engine

Field:

The invention belongs to an engine, in particular to an ultra-low-emission methanol fuel engine using methanol as fuel.

Background technique:

With the increasing scarcity of oil resources and stricter regulations on vehicle emissions, people have been looking for new technologies for efficient and clean combustion. Alternative fuels are an effective way to solve the crisis of oil resources and the pollution of internal combustion engines. The oil resource crisis can rise to a country's energy security. my country has become a net importer of crude oil since 1993, and the import of oil products has increased by 8-10 million tons per year. In 2000, my country imported about 70 million tons of crude oil. It is predicted that 47% of my country's total oil demand will be imported in 2010, and the supply of oil will be seriously insufficient. my country is a country rich in coal resources, rational use of coal resources is a necessary means to solve energy problems in my country's economic development. Methanol can be produced from coal and natural gas. Its combustion speed is fast, it is smokeless, flameless, and has low NOx emissions. Compared with gaseous fuels, methanol is easily transported, and its calorific value is about half that of gasoline. The global coal resource is much larger than that of oil. According to the current energy consumption level, it can be used for at least several hundred years. Therefore, methanol is the most promising engine fuel. Traditionally, methanol as an alternative fuel for engines mainly adopts two combustion modes, that is, the homogeneous ignition method based on the gasoline engine and the compression ignition method based on the diesel engine. The former has low thermal efficiency and the latter has higher emissions. The homogeneous charge compression combustion (HCCI) combines the advantages of the traditional compression ignition engine and ignition engine: Compared with the traditional compression ignition engine, HCCI is a homogeneous mixture compression ignition without diffusion combustion, so it greatly reduces Particulate emissions: Compared with traditional ignition engines, HCCI is compression ignition ignition, without throttling loss, and can use a larger compression ratio, so it has higher thermal efficiency; and, HCCI is different from traditional compression ignition and ignition Unlike the combustion of a conventional engine, the combustion process occurs simultaneously and homogeneously within the entire cylinder volume, rather than at the flame front, resulting in a lower combustion temperature, which greatly reduces nitrogen oxide (NOx) emissions.

Contents of the invention

The object of the present invention is to provide an ultra-low-emission methanol fuel engine that uses methanol as fuel and adopts HCCI combustion and compression ignition dual combustion modes. The engine can reduce the emission of the engine to the greatest extent and improve its thermal efficiency.

The technical solution of the present invention is: an ultra-low emission methanol fuel engine, characterized in that it is composed of an engine, a methanol tank, a catalytic converter with a heating device and an electronic control unit ECU; The fuel injection device is connected to the engine; the methanol tank is connected to the reactor in the catalytic converter installed on the exhaust pipe of the engine through the fuel delivery pump and the flow control valve, and the catalytic converter is connected to the dimethylformamide installed in the intake manifold through the pressure vessel. The ether solenoid valve is connected; the engine exhaust pipe is connected with the EGR valve, and the EGR valve is connected with the intake pipe; the input terminal of the electronic control unit receives the engine operating condition parameter signal output by the engine, the intake air temperature and pressure signal, the cooling water temperature signal, The temperature and pressure signals of the catalytic converter, accelerator position signal, top dead center signal, speed signal, crankshaft angle signal and knock sensor signal, the output end is connected with the flow control valve, dimethyl ether solenoid valve, methanol electronically controlled fuel injector, The glow plug, EGR valve and the electric heating device in the reactor are connected.

The above-mentioned electronically controlled medium-pressure common rail fuel injection device is composed of a methanol electronically controlled fuel injector installed on the engine cylinder, a glow plug, a high-pressure fuel pipe and a fuel return pipe; The oil delivery pump on the methanol tank is connected to the methanol tank through the oil return pipe.

The advantages of the present invention are: 1, greatly reducing the emission of particulates: 2, no throttling loss, and high thermal efficiency; 3, adopting the HCCI combustion mode, its combustion process occurs simultaneously and homogeneously in the entire cylinder volume, instead of Occurring at the flame front, the combustion temperature is lower, thereby greatly reducing nitrogen oxide (NOx) emissions. 4. It can save a lot of oil resources.

Description of drawings:

Fig. 1 is a structural representation of the present invention

Fig. 2 is a control block diagram of the present invention

Figure 3 is a schematic diagram of the combustion device

Figure 4 is a schematic diagram of the dimethyl ether airway injection device

Figure 5 is a schematic diagram of the control principle of the electronic control unit

Fig. 6 is the control flow chart of the engine in the working condition of load to medium and high load

Figure 7 is the control flow chart of the engine in cold start and hot car conditions

Figure 8 is a control flow chart when the working mode of the engine is a heavy load condition

Detailed ways:

As shown in Figures 1, 3, and 4: an ultra-low-emission methanol fuel engine (taking a four-cylinder engine as an example), consists of an engine 1, a methanol tank 2, a catalytic converter 3 with a heating device, a pressure vessel 4, and an electronic The control unit ECU is composed; the methanol tank is connected to the engine through an electronically controlled medium-pressure common rail fuel injection device; the methanol tank is connected to the reactor 8 in the catalytic converter installed on the engine exhaust pipe 7 through the fuel delivery pump 5 and the flow control valve 6 Connect, the reactor is connected with the pressure vessel; the pressure vessel is connected with the dimethyl ether solenoid valve 10 installed on the engine and connected with the intake manifold 9; the engine exhaust pipe is connected with the EGR valve, and the EGR valve is connected with the intake port ;

As shown in Figure 3: the above electronically controlled medium pressure common rail fuel injection device is composed of a methanol electronically controlled fuel injector 11, a glow plug 12, a high pressure fuel pipe 13 and a fuel return pipe 14 installed on the engine cylinder; the methanol electronically controlled fuel injector passes through The high-pressure oil pump 15 on which the high-pressure oil pipe is contained is connected with the oil delivery pump 16 on the methanol tank, and is connected with the methanol tank by an oil return pipe.

As shown in Figure 5: the input terminal of the electronic control unit receives the engine operating condition parameter signal output by the engine, the intake air temperature and pressure signal, the cooling water temperature signal, the temperature and pressure signal of the catalytic converter, the throttle position signal, the top stop Point signal, speed signal, crankshaft angle signal and knock sensor signal, the output end is connected with the flow control valve, dimethyl ether solenoid valve, methanol electronically controlled fuel injector, glow plug, EGR valve and electric heating device in the reactor.

As shown in Figure 2: the present invention adopts the novel engine with methanol as fuel, promptly uses pure methanol fuel on the traditional compression ignition engine. Methanol fuel is divided into two routes, one part is directly injected into the cylinder through the electronically controlled medium-pressure common rail fuel injection system, and the other is injected into the cylinder through the catalytic converter to generate dimethyl ether. Realize the HCCI combustion mode of DME single fuel during cold start, the HCCI combustion mode of DME and methanol dual fuel under medium and high load conditions, and the dual combustion mode combustion scheme of methanol compression combustion heated by glow plugs under heavy load conditions. The exhaust gas recirculation (EGR) technology is used to realize the HCCI combustion mode in a large range of operating conditions, and to control the equivalence ratio air-fuel ratio in the cylinder to 1. At the same time, the mature three-way catalytic conversion technology is used to reduce HC and CO emissions, so that the engine can achieve high efficiency and low pollution in all working conditions, and meet the requirements of emission regulations above European IV standards. The adoption of this technology will produce better economic and social benefits.

The working process of the present invention is: ECU reads signals such as engine throttle position, engine speed, air intake temperature and pressure, cooling water temperature, the temperature of catalytic reactor and pressure, at first judges the operating condition of engine, when engine is in start-up and When the car is hot, the electric heating device of the catalytic converter is activated, and the methanol flow meter is activated. At this time, the fuel is converted into dimethyl ether through the catalytic converter and injected into the cylinder from the intake port. The glow plug and the methanol injector are closed. The control flow chart is shown in Figure 7.

As shown in Figure 6: When the engine is under low load to medium-high load, the glow plug is closed, methanol is directly injected into the cylinder through the electronically controlled medium-voltage common rail system, and the other channel is converted into dimethyl ether through the converter and injected into the cylinder. , into the cylinder during the inflation process, adjust the methanol flow rate of the flow meter and the injection amount of dimethyl ether according to the working conditions, and adjust or close the electric heating device according to the temperature of the reactor.

As shown in Figure 8: When the engine is in a heavy load condition where HCCI cannot operate, the electric heating device and the electronically controlled methanol flow valve are turned off. At this time, methanol is only directly injected into the cylinder through the electronically controlled medium-pressure common rail system, and the The glow plug is turned on or off according to the operating conditions of the engine, and the methanol is controlled by pulsating multiple injections according to the working conditions to realize the quasi-homogeneous stratified combustion of methanol fuel. It is necessary to control the EGR ratio in the range of full load conditions of the engine so that the fuel-air equivalence ratio of the engine is 1 in the range of full load conditions.

Claims (2)

1, a kind of minimum discharge methanol-fueled engine is characterized in that: be made up of motor, methanol tank, the catalytic converter that has heating equipment and electronic control unit ECU; Methanol tank is connected with motor by pressing the common rail fuel injection device in automatically controlled; Methanol tank by oil transfer pump and flow control valve be installed in engine exhaust pipe on catalytic converter in reactor be connected, catalytic converter is connected with the dimethyl ether solenoid valve that is installed in intake manifold through pressurized container; Engine exhaust pipe is connected with the EGR valve, and the EGR valve is connected with suction tude; The input end of electronic control unit receives engine operation condition parameter signal, intake temperature and pressure signal, the cooling water temperature signal of motor output, temperature and pressure signal, throttle position signal, top dead center signal, tach signal, corner signal and the detonation sensor signal of catalytic converter, and output terminal and flow control valve, dimethyl ether solenoid valve, methyl alcohol electric-controlled fuel injector, glow plug, EGR valve are connected with Electric heating appliance in the reactor.

2, minimum discharge methanol-fueled engine according to claim 1 is characterized in that: the above-mentioned common rail fuel injection device of pressing in automatically controlled is formed by being installed on the cylinder methyl alcohol electric-controlled fuel injector, glow plug, high-pressure oil pipe and return tube; The methyl alcohol electric-controlled fuel injector is connected, is connected with methanol tank by return tube with oil transfer pump on the methanol tank by high-pressure oil pipe dress high pressure oil pump thereon.

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