Combustion condition of diesel engine by cylinder pressure oriented to control

According to demand of electronic control and combustion process measurement in diesel engine, cylinder pressure difference method was introduced to study combustion condition. Combustion parameters such as intensity, phase and heat-releasing rate were used to describe combustion condition. Combustion commencement angle, maximal burst pressure and its angle, and bar-center point in pressure difference curve were selected as character parameters to demonstrate overall combustion charater. The 4100 diesel engine was simulated with GT-POWER software, relation of pressure character index with injection timing and injection quantity was resolved by simulation and measurement of pressure data, and varying trend of each pressure character index with diesel engine emission NOx based on experimental data was analyzed. The results indicated that pressure character index had direct relationship with injection fuel timing and engine output parameter, and pressure character index could be used as combustion condition flag.