Exhaust gas recirculation method based on Miller cycle for secondary opening of exhaust valve

Abstract

The invention discloses an EVRO (exhaust valve secondary opening) IEGR (internal exhaust gas recirculation) method based on a Miller cycle. According to the method, through the cam profile design, an air inlet valve of a diesel engine is closed on a piston in a path, partial air in an air cylinder is pushed into an air inlet pipe, and the later closed Miller cycle work process of the air inlet valve of the diesel engine is realized; a double-peak exhaust cam is adopted, so an exhaust valve is opened once again in the gas inlet stroke of the diesel engine; under the effect of internal and external pressure differences in the cylinder, exhaust gas exhausted into the exhaust pipe is sucked into the air cylinder again, and the IEGR is carried out. According to the method, firstly, the LIVC Miller cycle and an EVRO-IEGR technology are combined, compared with the IEGR technology in the traditional Diesel engine diesel cycle, the method has the characteristic that the temperature of gas in the cylinder after heat insulation compression is reduced, the high-temperature environment in the cylinder is favorably improved, the generation of NOx is reduced, and the NOx emission reduction effect which cannot be achieved by the single IEGR technology is achieved.

Description

technical field [0001] The present invention relates to an exhaust valve secondary opening type exhaust gas recirculation method based on Miller cycle, which is a diesel engine NOx by implanting the exhaust valve secondary opening type internal exhaust gas recirculation technology into the diesel engine Miller cycle working process The emission reduction method belongs to the technical field of diesel engine emission reduction. Background technique [0002] Theoretical and applied studies of many internal and external purification technologies of diesel engines have shown that exhaust gas recirculation (EGR) is one of the effective measures to reduce nitrogen oxide (NOx) emissions. [0003] The mechanism of EGR emission reduction is to reduce the oxygen concentration of the gas in the cylinder by mixing a certain proportion of burned exhaust gas into the cylinder; through the increase of the total heat capacity of the gas in the cylinder by the burned exhaust gas, the purpos...

AI Technical Summary

Problems solved by technology

[0007] The invention discloses an exhaust valve recirculation method based on the Miller cycle for secondary opening of the exhaust gas in the machine, which is used to solve the problem of excessively high temperature in the cylinder of the traditional IEGR technology

Images