内燃兰金循环发动机爆震控制试验

Experimental Study of Knock Control in an Internal Combustion Rankine Cycle Engine

摘要:

基于一台改造的双缸柴油机，结合自行开发的进气及缸内高温水喷射系统，针对高压缩比、高氧浓度下内燃兰金循环发动机爆震工况开展试验研究.结果表明，与空气进气相比，高氧浓度进气会导致爆震出现，通过对缸内压力进行傅里叶变换和带通滤波后得到的爆震强度可达0.26 MPa.在爆震工况下结合缸内高温高压水喷射策略，可以有效抑制爆震强度，维持缸内燃烧过程稳定，与此同时，高温高压水吸热蒸发汽化，有效提高系统热效率.

Abstract:

Based on a retrofitted twocylinder diesel engine, combined with a selfdesigned intake and direct high temperature water injection system, the knock condition existed in internal combustion rankine cycle engine have been investigated at a high compression ratio and high oxygen fraction. The results show that compared with air intake, the knock occurred results in a high oxygen faction and the knock intensity (KIA) calculated from incylinder pressure Fourier transfer and bandpass filtering reaches 0.26 MPa. The knock frequency is controlled by utilizing a suitable direct water injection strategy and the combustion stability is sustained. Meanwhile, the injected high temperature and pressure water evaporate after heat absorption, which improves system thermal efficiency effectively.