正庚烷均质压燃发动机燃烧循环变动  

Cyclical variation of an HCCI engine fuelled by n-heptane

作　　者：薛乐[1] 张春化[1] 王娇[1] 

机构地区：[1]长安大学汽车学院,陕西西安710064

出　　处：《长安大学学报（自然科学版）》2014年第6期157-161,共5页Journal of Chang’an University(Natural Science Edition)

基　　金：陕西省自然科学基础研究计划项目(2012JQ7031)

摘　　要：为了研究均质压燃(HCCI)发动机燃烧的循环变动,在1台改装的HCCI发动机上进行了试验。通过改变进气温度、混合气浓度和运行转速等参数,研究了参数变化对正庚烷HCCI燃烧的影响。研究结果表明:随着过量空气系数从1.9增加到2.7,峰值压力的平均值从6.69 MPa降低到5.50 MPa,进气温度从30℃增加到70℃,峰值平均压力从5.49 MPa增加到6.44 MPa,所对应的曲轴转角位置也有所提前;随着转速的提高,峰值压力也有所增加,并且出现的时刻都有所提前;在转速为1 500r/min条件下,进气温度为30℃、过量空气系数为1.9时的循环变动系数最小,进气温度在50℃、过量空气系数为2.1时的循环变动最小,分别为2.89%和1.68%。可以得出最优的进气温度、混合气浓度等,使得HCCI发动机的燃烧稳定性得到保证。In order to study the cyclical variation of HCCI engines, a modified HCCI engine was used in the experiment. By changing intake temperature, mixture concentration and engine speed, the effects of parameter variation on n-heptane HCCI combustion were studied. The re- sults show that when k changes from 1.9 to 2.7, the mean value of peak pressure decreases from 6.69 MPa to 5.5 MPa, the intake temperature increases from 30 ℃ to 70 ℃, the mean peak pres- sure increases from 5.49MPa to 6.44 MPa and the corresponding crank angles are also advanced. With the increase of engine speed, the peak pressures increase and their timings are also ad- vanced. Under the condition that the engine speed is 1 500 r/min, the COV is the smallest when the in- take temperature is 30 ℃ and ）, is 1.9, and when the intake temperature of 50 ℃ and k of 2.1, which are 2. 89% and 1. 68%, respectively. Therefore, the optimal intake temperature and mixture concentration can be obtained to ensure the combustion stability of HCCI engines. 1 tab, 7 figs, 8 refs.

关 键 词：汽车工程 内燃机 均质压燃 正庚烷 循环变动 

分 类 号：U464.178[机械工程—车辆工程]