内燃机与动力装置 2019-10-02 09:40:05
（1.长城汽车股份有限公司技术中心，河北 保定 071000；2.河北省汽车工程技术研究中心，河北 保定 071000）
For the deposit phenomenon on exhaust ports and exhaust valves of turbocharged diesel engines, research about influence of valve timing on combustion and formation of deposit has been performed. The results show that too much in-cylinder residual gas leads to low combustion speed and longer combustion duration. Along with much earlier EVO, evaporated fuel in the cylinder will have no time to combust completely when being pushed out of the cylinder. After accumulating there will be deposits on exhaust valves and exhaust ports. By setting up suitable valve timing，in-cylinder residual gas can be reduced to reasonable level, leading to much faster combustion process. As a result deposits could be reduced or avoided.
Diesel Engine；Valve Timing；Residual Gas；Deposits