485 / 2018-12-31 13:48:39

Numerical Simulation of Combustion and Emission Characteristics of Low Heat Rejection Diesel Engine

emission,low heat rejection engine,combustion,simulation

全体主题 > 数值模拟、建模与CFD

In order to improve the performance of diesel engine and realize the improvement of fuel economy, low heat rejection diesel engine (LHR engine) is gaining attention. This paper calculate the transient heat transfer of baseline engine and LHR engine and adopts the numerical simulation method to analyze the combustion and emission characteristics of baseline diesel engine and LHR engines with different insulation. The convection and total heat transfer rate of baseline engine are much higher than that of partially insulated LHR engine, but there is no significant difference in radiation heat transfer rate between baseline engine and partially insulated LHR engine. Through the analysis of the simulation results of engines with insulation degree 0%, 20%, 30%, it is found that when the insulation degree increases, the initial ignition point is advanced, and the ignition delay period is shortened, the combustion duration lengthens. As the insulation degree increases, the temperature rises rapidly, resulting in a faster rate of NO generation and the final generation is smaller. The soot generation of LHR engine which insulation degree is 20% is the lowest.