Investigation on the effect of start of injection timing on the capacity of waste heat recovery from RCCI engines

The main part of the input energy to the cylinder of an internal combustion engine is lost by various factors, and only about one third of this energy becomes useful. Therefore, providing solutions that can recover waate heat from engine exhaust gases and coolant is remarkable and useful. In current study the effect of start of injection timing on the RCCI engine on the waste heat recovery capacity has been investigated. A CFD model is used to simulate the engine. At first, the model was verified using experimental data and then the diesel fuel start of injection timing has been changed and their effects on exergy destruction, waste heat recovery capacity, power output and emissions have been investigated. The results showed that advanced start of injection timing, increases engine efficiency and decrwases exhaust CO and HC emissions. In addition to, heat transfer exergy has increased due to the the higher in cylinder temperature, and the higher temperature has led to an increase in irreversibility due to the increased number of reactions. Advanced fuel injection timing has improved the utilization factor and higher value of utilization factor is obsereved when fuel is injected at 20 CAD before TDC