基于废气氧体积分数修正喷油量的试验研究

Experimental study on fuel injection quantity based on volume fraction of oxygen in exhaust gas

为提高喷油控制的精确性,研究基于废气中氧体积分数修正喷油量的方法,根据废气中氧体积分数、过量空气系数、进气量计算实际喷油量以及设定喷油量和实际喷油量的偏差,并进行喷油量修正和油量闭环控制;在发动机台架上进行喷油量偏差试验,分析喷油器偏差试验结果。结果表明:喷油器正常时的喷油量相对偏差为-2.90%~1.00%,模拟喷油器磨损时的喷油量相对偏差为-3.42%~0.83%,偏差较小,基于废气中氧体积分数修正喷油量的方法可行、精确。

To accurately control the fuel injection amount,a method of correcting the fuel injection amount based on the oxygen volume fraction in the exhaust gas is studied.The actual fuel injection amount is calculated based on the oxygen volume fraction in the exhaust gas,excess air coefficient,and intake amount,as well as the deviation between the set fuel injection amount and the actual fuel injection amount.The fuel injection amount correction and closed-loop control are carried out,and the fuel injection amount deviation test is conducted on the engine bench to analyze the results of the fuel injector deviation test.The results show that the relative deviation of fuel injection rate under normal conditions is-2.90%to 1.00%,while the relative deviation of fuel injection rate under simulated injector wear is-3.42%to 0.83%,which is a small deviation.The method of correcting fuel injection rate based on oxygen volume fraction in exhaust gas is feasible and accurate.