Investigative analysis of light duty diesel engine through dual loop organic Rankine cycle

Abstract

Ecology prevention and energy conservation are the two important concerns being faced by the world. Due to modernization, the demand for energy increases and this growing energy demand disturb the ecology by increasing the greenhouse gases. Consequently, energy conversion of fossil fuel with minimum wastage has become crucial aspect. Present work is focusing to retrieve the waste heat from a diesel engine which utilizes only 35% of fuel energy as the useful energy and rest goes waste. A dual-loop Organic Rankine Cycle (ORC) is opted to recover waste heat from an internal combustion diesel engine. The study considered a Toyota Innova light-duty diesel engine, where heat is extracted from the intake air, coolant system, and engine exhaust. Heat energy is recovered by dual loop Organic Rankine Cycle, as a hot temperature loop and cold temperature loop. R245fa refrigerant is used in the hot temperature loop, which recovers heat energy from exhaust gases. Whereas R134a refrigerant is used for low-temperature loop (LT), and it recovers residual heat of hot temperature (HT) loop, intake air and coolant system. By applying thermodynamic analysis on the combined system, the performance analysis of the twin loop is observed. Further the combined system performance in terms of specific fuel consumption and network are investigated. It is observed through simulation results, that around 50% improvement in work output and by around 20% reduction in brake specific fuel consumption due to waste heat recovery.