High pressure air spray assistant power supply control strategies and their effects on diesel engine under transient operations

Abstract

In order to reduce smoke from direct-injection (DI) turbo-charged and after-cooled (TCA) diesel engines under transient operations, the real-time controlling and measuring system of a high pressure air spray assistant power supply (HPAS) was developed. Effects of HPAS on a DI TCA diesel engine under constant engine speed and increased torque (CSIT) transient operations were studied by using different control strategies. Pre-spray (PS) strategy, which means supplying highly pressurized air into the exhaust manifold two seconds before the accelerating-graph begins to rise and stopping spraying air when the accelerating-graph stops rising. Two other strategies—full-time-spray (FTS) and middle-time-spray (MTS)—were used to fully exploit HPAS potential. With the FTS and MTS strategies, the HPAS system can remarkably decrease smoke from DI TCA diesel engines under transient operations.

Keywords

diesel engine, transient operations, smoke opacity, high pressure air spray