直喷式柴油机缸内气体辐射传热的研究

Investigation on In-Cylinder Radiation from Gases in DI Diesel Engine

在一台直喷式柴油机上实测了气缸内辐射和火焰辐射热流量,在此基础上,研究了气缸内气体辐射传热及其随负荷和转速变化的规律,分析了气体辐射热流量占气缸内辐射热流量和总热流量的比例随负荷和转速变化的规律.研究表明:气体辐射热流量随负荷的增加而增大,随转速的升高而减小;气体辐射热流量约占辐射热流量的15%~30%左右,此比例随负荷的减小、转速的升高而增大;气体辐射热流量约占气缸内总热流量的3%~5%左右,此比例随着负荷及转速的增加而减小.

Experiments were carried out on a DI diesel engine to examine the radiation and flame radiation heat flux in the cylinder of a diesel engine. On the basis of the experiments, the behavior of gas radiation heat transfer versus engine load and speed was studied. The ratios of gas radi- ation heat flux to radiation heat flux and total heat flux were also investigated. The results show that the gas radiation heat flux increases with increase of load and decrease of speed. The gas ra- diation heat flux ratio is about 15 ^-30 % of the radiation heat flux in the cylinder of the diesel engine and it increases with decrease of load and increase of speed. In addition, the gas radiation heat flux ratio is about 3%-5% of the total heat flux in the cylinder of the diesel engine, and the ratio decreases with increase of engine load and speed.