【摘要】 针对两级相继增压(TSST)柴油机增压模式切换过程的性能恶化问题，基于改造的两级相继增压柴油机试验平台，开展了增压模式切换试验，探明了负荷与进气切换阀(ISV)延迟开启时间对切换过程的影响规律．结果表明：两级相继增压系统可在全工况范围降低燃油消耗率，以经济最优为目标制定不同增压模式切换边界为65%负荷，并在考虑排放与切换冗余的基础上进行拓宽；随着负荷升高，切换过程中增压压力波动的幅度增大，排气压力突变程度加大，导致更严重的柴油机转速波动；切入分支高压级压气机出口端的进气切换阀延迟开启可减小切换过程的性能波动．不同负荷下存在对应的最优进气切换阀延迟开启时间，为压气机无倒流时的阀门前、后压力相等时间，随着负荷升高，该最优值缩短；在最佳的阀门延迟控制下，压气机喘振和倒流现象基本消失，转速波动抑制率可达82.47%，实现增压模式的平顺切换．更多还原

【Abstract】 Aiming at the performance deterioration of the turbocharging mode switching process of a two-stage sequential turbocharging(TSST) diesel engine,a test of turbocharging mode switching was carried out on a modified TSST diesel engine test platform to investigate the influence of engine load and delayed opening time of intake switching valve(ISV) on the switching process. The test results show that the TSST system can reduce fuel consumption rate in the full range of operating conditions,and the switching boundary of different turbocharging modes is set at 65% load with the goal of economic optimization,which can also be broaden based on the consideration of emissions and switching redundancy. As the load rises,the amplitude of boost pressure fluctuation increases during the switching process,and the degree of sudden change in exhaust pressure increases,resulting in the more serious speed fluctuation of the diesel engine. By delaying the opening of the ISV at the outlet of the high-pressure stage compressor of the cut-in branch,the performance fluctuation can be minimized. Under different loads,there exists an optimal delayed opening time of the ISV,which is the time when the pressure before and after the valve is equal without backflow in the compressor,and the optimal value is shortened with the load increases. Through the optimal valve delay control,the surge and backflow phenomena of compressor are significantly alleviated. The decrease of speed fluctuation can be up to 82.47%,realizing the smooth switching of different turbocharging modes.更多还原