燃油性质与喷油参数对陶瓷隔热复合机燃烧过程的影响

Effects of Fuel Properties and Injector Parameters on Combustion in a Ceramic Heat Insulated Compound Engine

摘要在定容燃烧装置与B1135型单缸机上,对陶瓷隔热复合机的燃烧过程进行了试验研究.结果表明,由于陶瓷隅热复合机的压缩终点温度和压力很高,使滞燃期过短,空气粘度高,着火点在喷油嘴孔口附近,初期火焰横贯喷注,使空气与燃油混合条件差,因而仍沿用常规发动机燃烧系统参数时,燃烧过程恶化、燃油消耗率上升.采用减小喷油嘴孔径、增多喷孔数以改善空气与燃油的混合条件,以及采用低16烷值、低粘度燃油以获得滞燃期加长、着火点远离孔端等措施.对改善陶瓷隔热复合机燃烧过程具有良好的效果.

Combustion process of a ceramic heat insulated compound engine was experimentally studied in a constant-volume combustion bomb and a B1135 type single-cylinder diesel engine. It was found that because of elevated air temperature and pressure in heat insulated engine, ignition occured near injector nozzle holes, inital flame crossed fuel spray due to short ignition delay and high air viscosity, leading to deterioration of fuel-air mixing. Combustion in heat insulated engineappeared unsatisfactory with conventional combustion system. Reducing nozzle hole diameter and corresponding increasing hole number to improve fuel-air mixing, using fuel with low cetane nnumber and low viscosity to prolong ignition delay and cause ignition occuring far from nzzle hole, might improve significantly combustion process in this kind of engine.