冒烟限制对重型电控柴油机加速瞬态性能影响试验研究

Experimental Study on the Effect of Smoke Limitation on Accelerated Transient Performance of Heavy Duty Electronically Controlled Diesel Engine

本文研究了冒烟限制λ值对某重型柴油机恒转速增转矩瞬态工况的动力性、经济性和排放性的影响。随着冒烟限制λ值的增大,实际循环喷油量的最大值减小,实际循环喷油量与冒烟限制下最大循环喷油量重合时间增加;循环进气量呈现降低的变化趋势,随后与循环喷油量变化趋势相似,时刻相对滞后;过量空气系数降低;减小瞬变过程中的最大极限喷油量,使动力性变化滞后。冒烟限制λ增加2.5%和减小2.5%后,瞬变过程的累积功率相对原值分别降低0.22%和增加0.21%,有效燃油消耗率比原值分别降低了0.39%和1.2%。可见,增大加速冒烟限制λ值,有利于降低瞬变过程中烟度排放峰值以及NO_X排放的累积量,但烟度排放累积量将大幅增加。

In this paper, the influence of the smoke limit λ on the dynamic performance, economy and emission performance of a diesel engine under constant torque and transient torque conditions is studied. With the increase of the smoke limit λ, the maximum value of the actual circulating fuel injection quantity decreases, and the coincidence time of the actual circulating fuel injection amount and the maximum circulating fuel injection amount under the smoke limit increases; the circulating intake air amount shows a decreasing trend, Followed by a similar trend with the cycle of fuel injection volume, time lag; excess air coefficient decreases; reduce the maximum transient injection process limit, so that dynamic changes in hysteresis. The cumulative power of the transient process decreases by 0.22% and 0.21%, respectively, and the effective fuel consumption rate is reduced by 0.39% and 1.2%, respectively, compared with the original value after 2.5% and 2.5% reduction respectively. It can be seen that the increase of the emission limit of λ is beneficial to reduce the peak value of smoke emission and the accumulation of NOX in the transient process, but the smoke accumulation will increase greatly.