碰撞式全气缸取样机构及其初步应用

将自行开发的碰撞式全气缸取样机构应用于一台S1115柴油机有害污染物缸内形成历程的研究。对取样过程的分析结果表明,由于取样阀的质量较大,导致其开启速度较低,取样过程中缸内气体的流出速度较慢,压力半衰期较长;而压力半衰期三次多项式拟合曲线具有较高的相关系数(大于0.97),表明碰撞式取样机构具有很好的取样重复性。对碳烟、CO和NOx的测量结果表明,利用该取样机构进行的全气缸取样试验能够清晰地反映出被测对象的缸内形成与转化历程并与其普遍规律相一致,所开发的取样机构可以用于全气缸取样研究。

Total Cylinder Sampling System Based on Impact Theory and Its Preliminary Application

An experimental study was held using the homemade total cylinder dumping system based on impact theory to investigate the in-cylinder formation process of harmful pollutants for a S1115 diesel engine. The results showed that the low mass flow ratio of burned gas that was caused by the great inertia of sampling valve prolonged the half life of pressure drop. The better sampling repeatability of impact type sampling system was testified by the higher correlation coefficient, which was bigger than 0.97, of cubic polynomial fitting curve for the pressure half-life. The results of measuring soot, CO and NOx show that the in-cylinder formation and conversion course that is in accordance with universal law can be clearly reflected by total sampling test with sampling system. Accordingly, the developed sampling system can be applied to the research of total cylinder sampling.