High compression ratio spark-ignition type engine

Abstract

A high compression ratio spark-ignition engine includes an inlet manifold, an exhaust manifold and an air inlet throttle valve. An EGR valve and an EGR cooler are connected at the lower sequence of the exhaust manifold in sequence; the high compression ratio spark-ignition engine is characterized in that a venturi pipe is connected at the back end of the air inlet throttle valve, and an exhaust end of the venturi pipe is connected with the exhaust manifold of the engine. A metering hole is arranged in the middle of the venturi pipe and the exhaust end of the EGR cooler is connected with the metering hole. The high compression ratio spark-ignition engine mixes proportional waste gas with fresh air in the venturi pipe through the EGR valve and the EGR cooler, and then the mixed gas is absorbed by the engine so as to largely restrain phenomenon of detonation. By using methanol or gas fuel, the compression ratio can be improved to 15 and even more. The air inflow can be automatically adjusted by the throttle valve so as to prevent gas mixture from firing due to being over-thin under medium and small loads. The waste gas can be accelerated by a waste gas turbine to keep smooth exhaust. A turbine gas compressor for auxiliary intake is additionally installed, thus improving intake pressure and guaranteeing the supply of oxygen of the engine.

Description

technical field [0001] The invention relates to a spark ignition engine, especially a high compression ratio engine using methanol or natural gas as fuel. Background technique [0002] The spark ignition engine uses the spark ignition combustion method of the homogeneous mixture, which has the advantages of low noise and low emission compared with the spray mixed compression ignition combustion method of the diesel engine. However, due to the limitation of the knock limit, its compression ratio is generally low. For high-octane fuels such as methanol or natural gas, the compression ratio cannot exceed 13. For example, the HL-495 methanol engine currently on the market, due to the low compression ratio, the fuel economy of the engine is 15-20% lower than that of a diesel engine. [0003] Chinese Patent No. 200610139512.1 discloses "combustion chamber structure of spark ignition engine"; "It is all about increasing the compression ratio by changing the structure of the engine...

AI Technical Summary

Problems solved by technology

[0002] The spark ignition engine uses the spark ignition combustion method of the homogeneous mixture, which has the advantages of low noise and low emission compared with the spray mixed compression ignition combustion method of the diesel engine. However, due to the limitation of the knock limit, its compression ratio is generally low. For high-octane fuels such as methanol or natural gas, the compression ratio cannot exceed 13. For example, the HL-495 methanol engine currently on the market, due to the low compression ratio, the fuel economy of the engine is 15-20% lower than that of diesel engines

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