大滚流气道对PFI发动机性能影响的试验研究

Testing Study on the Performance Influenced by High Tumble Intake Port in PFI Engine

进气道是发动机进气系统的重要组成部分。增加进气道的滚流比,提高缸内的湍动能,从而改善燃烧,进而改善了发动机的性能。本文对一台1.5L增压气道喷射发动机进行了台架试验,获得了采用大滚流气道时发动机的性能状况;同时基于大滚流气道对比分析了配合原活塞和配合平顶活塞时发动机性能情况。试验表明,在低速小负荷工况下,滚流比的提高,对发动机油耗改善不明显;低速大负荷工况下,滚流比提高,改善了发动机的燃烧,降低了爆震倾向;在功率点附近的工况,滚流比的增大,导致燃烧相位滞后,油耗升高。

Intake port is an important part of engine's intake system.Increasing tumble ratio of intake port and turbulence in cylinder will optimize combustion and thus improve engine performance.A 1.5L turbo PFI engine is tested on the rig and there are some data about engine performance with high tumble intake port in the paper;At the same time,the engine performance is compared and analyzed with original piston or flat piston based on the high tumble intake port.The test show:there is no obvious improvement in fuel economy with high tumble ratio in low speed low load;the combustion is improved and knocking tendency is decreased with high tumble ratio in low speed high load;the combustion phase is retarded and fuel economy gets worse with high tumble ratio around 5600rpm working conditions.