配气正时对工质移缸类非常规循环内燃机性能的影响规律

Influence of Valve Timing on Performance of Unconventional Internal Combustion Engine with Charge Transit Between Different Cylinders

将一台传统四缸四冲程汽油内燃机改造成一个具备工质移缸特征的新型循环内燃机,通过实验和模拟计算方法研究了前缸排气正时和后缸进气正时对分缸循环内燃机性能的影响规律。新循环内燃机中2个气缸完成1个工作循环,前缸为传统四冲程循环燃烧气缸,后缸为非燃烧气缸,前缸的燃气通过转接管进入后缸,再从后缸排出内燃机。基于GT-POWER模型对新循环内燃机建立一维仿真模型,并进行了仿真和实验验证。结果表明:在不改变气门升程曲线的情况下,前缸排气提前角和后缸进气提前角对内燃机燃油消耗率的影响较小,对内燃机扭矩外特性影响较大;新循环内燃机燃油消耗率低于原机,说明前缸燃烧、后缸继续膨胀的内燃机分缸循环可以提升内燃机的工作效率。

A conventional 4-cylinder 4-stroke gasoline IC engine was transformed into an innovative IC engine with the technology of charge transit between different cylinders. To learn influence of the valve timing on the performance of the IC engine with charge transit, the exhaust advance angle of the front cylinder and the intake advance angle of the rear cylinder were examined by experiment research and simulation calculation. In this new IC engine, a working cycle is completed by a pair of cylinders. The front cylinder is a conventional 4-stroke combustion cylinder while the rear cylinder is a cylinder without combustion performing on a 4-stroke cycle. The burned gas is transferred from the front cylinder to the rear cylinder through a connection pipe, and then the gas is exhausted out of the engine from the rear cylinder. A 1D simulation model of the new engine was established by GT-POWER, and its accuracy was verified by the experimental data. The results show that, when the valve lift curve keeps constant, the exhaust advance angle of the front cylinder and the intake advance angle of the rear cylinder have slight influence on the engine fuel consumption but they have great influence on the external characteristics of the engine torque. The fuel consumption of the new engine is lower than that of the original engine, indicating that the split cycle with the front cylinder combustion and rear cylinder expansion could improve the IC engine working efficiency.