柴油机冷起动时放热规律计算研究

AN ANALYSIS ON HEAT RELEASE RATE OF DIESEL ENGINE DURING COLD STARTING PROCESS

实测柴油机冷起动过程气缸压力及瞬时转速，考虑瞬时转速变化进行冷起动过程放热规律计算分析，结果表明转速较低时，瞬时转速对放热规律计算有较大的影响。

The heat release rate of a single cylinder, four stroke, direct injection diesel engine during cold starting process was calculated and analyzed based on the measured cylinder pressure and engine transient speed. The engine transient speed decreases during compress stroke and increases during power stroke. This phenomenon abates with the engine speed increasing in the cold starting process. The heat lose is higher in the beginning of cold starting process because the engine speed is low and the heat conducting time is long. It is found that the engine transient speed has great influence on the calculation of heat release rate when the engine speed is low.