柴油机燃用生物柴油低温燃烧性能的仿真研究

采用GT-Power软件模拟分析了不同EGR率和喷油正时对柴油机燃用生物柴油低温燃烧性能的影响。研究表明:随着EGR率的增加,最高燃烧压力下降,缸内最高平均温度逐渐升高,燃烧相位后移,有效燃油消耗率增加,热效率降低,NOx排放大幅度降低,炭烟排放、CO排放和THC排放都升高。在相同的EGR率下,随着喷油正时的延迟,最高燃烧压力和缸内平均燃烧温度降低,燃烧放热相位后移,燃油消耗率先减小后增加,热效率先升高后降低,NOx排放降低,炭烟排放先升高后降低,CO排放和THC排放同时升高。通过调节EGR率和喷油正时可同时使NOx排放和炭烟排放低于原机,但是会导致燃油消耗率和热效率大幅度恶化,且CO和THC排放升高。

Simulation of Low-Temperature Combustion Performance for Diesel Engine Fueled with Biodiesel

The effects of different EGR rates and injection timings on low-temperature combustion of biodiesel engine were simulated and analyzed by GT-Power.The results show that the combustion phase moves backward,the maximum combustion pressure,the thermal efficiency and the NOx emission decrease and the highest average in-cylinder combustion temperature,the brake specific fuel consumption and the soot,CO and THC emissions increase with the increase of EGR rate.With the delaying of injection timing at the same EGR rate,the combustion phase still moves backward,the maximum combustion pressure,the average in-cylinder combustion temperature and the NOx emission decrease,the CO and THC emissions increase,the brake specific fuel consumption first decrease and then increase and the thermal efficiency and soot emission first increase and then decrease.In addition,adjusting the EGR rate and injection timing can reduce both NOx and soot emissions,but will result in a significant deterioration in fuel consumption and thermal efficiency as well as CO and THC emissions.