Improving the combustion and emission characteristics of ISM 370 diesel engine by hydrogen addition and redesigning injection strategy

摘要

Hydrogen fuel is the cleanest fuel available. This fuel can be used as an additive in the diesel engine. Diesel engines have the advantages of strong power, high thermal efficiency and low fuel costs. There have been extensive studies on the use of hydrogen fuel in diesel engines in recent years. However, the simultaneous effect of using gaseous hydrogen fuel and changing injection strategy needs further investigation specially for the Cummins ISM370 engine. This work considers almost all functional and emission parameters, simultaneously. This procedure can be effective to achieve balanced conditions when 6% H2 (by volume) is injected into the Cummins ISM 370 diesel engine (under different engines). In addition, due to changing fuel compound used in engine, injection timing and temperature of engine should be redesigned to better operating. For simulation of engine, a CFD code was used. In order to validity and verify the simulation predicted mean pressure and the rate of heat release are compered to experimental data and results gave appropriate accordance. Results show that most of exhaust emissions such as NO, CO, etc. are dramatically reduced by using gaseous hydrogen under various engine speeds. It is determined that with addition of 6% H2 within the engine, indicated thermal efficiency is increased by around 39%; and NO, soot, CO and CO2 emissions are reduced by 5%, 75%, 70%, and 30%, respectively, under 1600 rpm speed. It is also found that the best injection timing that makes a balance between exhaust emissions and performance parameters is 4 deg BTDC under 2000 rpm. Moreover, the best injection temperature is 330 K among of three considered injection temperatures.