基于AVL-FIRE的生物柴油/正丁醇混合燃料燃烧与排放特性仿真分析

Simulation analysis of combustion and emission characteristics of biodiesel/n-butanol blends based on AVL-FIRE

【目的】研究生物柴油-正丁醇混合燃料的燃烧与排放特性.【方法】基于AVL-FIRE燃烧仿真软件对BD100、BD90N10、BD70N303种不同掺混比的生物柴油-正丁醇混合燃料进行缸内燃烧仿真与分析,对比3种不同燃料的缸内压力,温度分布,NOx和soot排放.【结果】在发动机1400r/min,小负荷工况下运行且循环喷油量一定时,随着混合燃料中正丁醇掺混比的增大,缸内最大爆发压力减小,但峰值都出现在7°CA附近;缸内温度略有降低.由于正丁醇汽化潜热大,导致缸内混合气温度降低,因此随着正丁醇掺混比的增大,混合燃料的氮氧化物排放降低;正丁醇的高含氧量能够使混合燃料的碳烟排放降低.【结论】随着正丁醇掺混比的增大,缸内最大爆发压力减小;缸内温度略有降低.

【Objective】 To study the combustion and emission characteristics of biodiesel-n-butanol blended fuel.【Method】 Based on AVL-FIRE combustion simulation software,the in-cylinder pressure,temperature distribution,NO x and soot emissions of three different fuels of BD100,BD90N10 and BD70N30 were analyzed.【Results】 When the engine operating at 1 400 r/min and large load conditions with a certain amount of circulating fuel injection,with the increase of n-butanol blending ratio,the maximum pressure in the cylinder decreased,but the peak value appeared around 7 ° CA.The temperature in the cylinder decreased slightly.Due to the large latent heat of vaporization of n-butanol,the temperature of the gas mixture in the cylinder was decreased.Therefore,with the increase of the n-butanol blending ratio,the NOx emission of the mixed fuel decreased.The high oxygen content of n-butanol enables the mixed fuel of soot emissions reduced.【Conclusion】 With the increase of n-butanol blending ratio,the maximum burst pressure in the cylinder decreases;the temperature in the cylinder decreases slightly.