화학공학소재연구정보센터
Applied Energy, Vol.242, 462-479, 2019
Numerical investigation of reactivity controlled compression ignition (RCCI) using different multi-component surrogate combinations of diesel and gasoline
The role of chemical mechanisms in studying the combustion phenomenon is very important. These mechanisms, if formulated properly, can make a numerical investigation more accurate and time-saving. In this study, a multi component surrogate has been presented after integrating two previous mechanisms to study the combustion chemical kinetics. The mechanism contains a total of six components, 168 species and 680 reactions and has been validated extensively. The validations have been carried out for individual and mixture of components over a wide range of temperatures and pressures. The mechanism showed a good overall agreement with the experimental data. In order to do an application-based kinetic study, this mechanism was later used to study the combustion characteristics of Reactivity Controlled Compression Ignition (RCCI), which is a low-temperature and dual fuel combustion concept. The combustion characteristics have then been investigated considering the impact of single and multi-component surrogates on chemical and physical properties. First, only chemical properties and then physical properties have been changed followed by a change in both properties by a multi component mechanism. The in-cylinder pressure and heat release rates have been captured well by multi component surrogate fuel representing both physical and chemical properties of multi-component surrogate. The NOx and soot emissions have been predicted well by using a combination of physical and chemical properties of multi-component and single component surrogates for diesel and gasoline, respectively. The chemical kinetics analysis was performed at points of five percent (CA5) and fifty percent (CA50) of total heat release using sensitivity and consumption reaction pathways analyses. These analyses showed an overall more production of OH, CH2O and CO2 in multi-component surrogate fuel which enhanced the overall heat release rate. Toluene and cyclohexane were observed to inhibit the reactivity of multi-component surrogate fuel. They, on the other hand, also control the low-temperature heat release rates and enhance the high-temperature heat release rates.