The Study Of Non-road Spark-ignition Small Engines Pressure Acquisition And Combustion Analysis System

In this paper, Non-road Spark-ignition Small Engines pressure acquisition and combustion analysis system are investigated. The system consists of data acquisition system and engine cylinder pressure acquisition and combustion analysis software.The information of indicator diagram is important to investigate in-cylinder working process in engine. We can get many physical parameters through indicator diagram acquired in the experiment. Such as indicator work, mean indicated pressure, maximal pressure and corresponding crank angle, maximal rate of pressure rise and correspond ding crank angle and mass fraction burned, heat release rate, etc. These physical parameters can analyze and show primary in-cylinder combustion process in engine.Modern cylinder pressure acquisition system is deeply affected by the advanced computer hardware technology, include A /D card with the capabilities of high resolution, high sampling rate, non discrepancy and setting sampling rate at will is combined with a lot of excellent measuring equipment such as crank shaft angle encoder, charge amplifier, industrial control computer, etc. We use a 6117B spark plug cylinder pressure sensors made by Kistler corp., Switzerland. Cylinder pressure data can be sampled and conveniently analyzed to identify the combustion conditions in all cylinders. The engine is motored in research of position of dynamic TDC for combustion analysis needs exact reference information. Considering the different disturbance signals in the laboratory, hardware and software setting measures were taken to reduce these disturbances.Visual Basic.NET is used to develop Non-road Spark-ignition Small Engines pressure acquisition and combustion analysis software. Based on Software Engineering guidance, the idea of object-oriented programming runs through whole developing process. The software interface is designed simply and easily operated and independent modules are convenient for extending more functions. One analog channel can sample cylinder pressure signal, fifteen spare analog channels are reserved. The acquired data need to be analyzed and treated with some mathematic methods, and cylinder indicator diagrams, rate of pressure rise diagrams, the burned mass fraction diagrams and rate of the burned mass fraction rise diagram can be drawn.Cylinder pressure data at different speed and load were sampled in experiments of SL1P68F engine. The author studied the heat release rate and heat efficiency on of Non-road Spark-ignition Small Engines, and the E10, E50 and E95 of different load and speed, and this verified that the combustion system meet the need of study.