生物柴油放热规律预测模型与试验分析

Prediction Model and Experimental Analysis of Biodiesel Heat Release

用燃烧生物柴油的直喷式柴油机示功图数据,计算了生物柴油的放热规律,并应用双韦伯函数对标定转速和最大转矩转速的生物柴油放热规律进行了拟合。在此基础上,提出了生物柴油放热规律的双韦伯函数的修正参数,建立了不同配比混合燃料的双韦伯函数修正系数,对其他工况的生物柴油及混合燃料的放热规律进行了预测。预测结果表明:生物柴油比例高的混合燃料的燃烧始点、最大放热率、放热第二峰值有所提前,其中预混合燃烧阶段的燃烧峰值较小,扩散燃烧阶段的放热峰值较大,预混合燃烧期缩短。

By using the data recorded in-cylinder pressures in direct injection diesel engine is used to calculate heat release rate of biodiesel and using double Wiebe＇ s Functions to simulate the speed of maximum torque and teclared operating, The parameter of double Wiebe＇ s Functions were amended, using the amended parameter of different blended fuel. Forecast heat release rate of biodiesel and different blended fuel. It is shows that with more composing of biodiesel in blended fuel the combustion start point, the maximal heat release rate and the second heat release rate are advance ,the maximal heat release rate in premixed combustion phase is less, but it is more in diffusive combustion. Also duration of premixed combustion and diffusive combustion is shortened.