Direct spraying natural gas two-air valve engine underpressure layered combustion chamber structure in cylinder

Abstract

The invention relates to a natural gas engine, in particular to a lean burn layered combustion chamber structure of a direct injection natural gas two- valve engine. The combustion chamber structure comprises a piston, an air cylinder cover, an air cylinder, an intake valve and an exhaust valve, and is characterized in that a top face of the piston is provided with a flow guide pit; a natural gas nozzle part is arranged on the air cylinder cover closes to a part with a larger curvature radius of the flow guide pit; a spark plug is also arranged on the air cylinder cover at a position corresponding to that of the natural gas nozzle and is close to a part with a smaller curvature radius of the flow guide pit. In the structure, the flow guide pit 8 is arranged on the top of a protruding piston, and the natural gas nozzle aligns with the part with a larger curvature radium of the flow guide pit 8 and can cooperate with the spray time and motion of the piston to guide a spray beam and with the flow of compressed air to increase the concentration of the natural gas near the spark plug so as to form uneven layered mixed gases during lean burning to improve ignition performance and combustion performance of the engine.

Description

technical field [0001] The invention relates to a natural gas engine, in particular to an in-cylinder direct-injection natural gas two-valve engine with a lean stratified combustion chamber structure. Background technique [0002] With the advent of the new century, human beings are facing the dual pressure of economic growth and environmental protection, changing the way of energy production and consumption, using modern technology to develop and utilize new energy such as natural gas, to establish a sustainable energy system and promote social and economic development It is of great significance to improve the ecological environment and get rid of the dependence on fossil energy. [0003] Natural gas is favored by people for its outstanding advantages of cheap price and low emission pollution, and is considered to be the most potential alternative fuel for engines. At present, there are two main working modes of natural gas engines: one is a dual-fuel engine that uses die...

AI Technical Summary

Problems solved by technology

In 1994, Mitsubishi Motors Corporation developed an in-cylinder direct-injection gasoline engine, which uses a longitudinal air passage to form a strong tumble flow in the cylinder, a rich mixture gas is formed around the spark plug, and a rich-to-lean mixture gas stratification phenomenon is formed from the spark plug to the combustion chamber space. It can reduce fuel consumption by 20% and increase the maximum torque by 6% and 8%. However, due to fuel stratification, there is still the problem of soot emission in the rich mixture zone combustion

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