喷水温度对缸内喷水柴油机燃烧及性能影响的试验研究

Experimental Study on Effect of Water Injection Temperature on Combustion and Performance of In-cylinder Water Injection Diesel Engine

摘要:

基于一台双缸机械泵柴油机，结合自行开发的高压共轨喷射系统、缸内高温水喷射系统及高性能控制平台，试验研究不同喷水温度下的缸内喷水技术对柴油机燃烧及性能的影响.结果表明，随着喷水温度从25 ℃提高至160 ℃，喷入缸内高温高压环境的水的蒸发速度改善，缸内有效做功工质增加，膨胀行程做功量可实现约49.5 J的优化，柴油机指示热效率提高8%.与此同时，提高喷水温度可改善缸内水雾蒸发速率，从而降低缸内燃烧过程的循环波动.

Abstract:

Based on a two-cylinder mechanical pump diesel engine, combined with self-developed high pressure common rail injection system, in-cylinder high temperature water injection system and high performance control platform, the effect of water injection temperature on combustion and performance of diesel engine was investigated. The results indicate that, by improving water injection temperature from 25 ℃ to 160 ℃, the evaporation rate of in-cylinder water vapor is enhanced, the mass of in-cylinder work fluid is improved, therefore, the work during expansion stroke can be optimized about 49.5 J, and an 8% enhancement in thermal efficiency of the diesel engine can be achieved. Meanwhile, the optimized water vapor evaporation speed is beneficial to the decrement of combustion cyclic fluctuation.