Energy and exergy analysis of combined ORC – ERC system for biodiesel-fed diesel engine waste heat recovery

Abstract

A combined cooling, heating, and power generation system is proposed for the recovery of exhaust waste heat of the diesel engine. The engine rejected heat recovery system consisted of a domestic water heater (DWH), an organic Rankine cycle (ORC) and an Ejector Refrigeration Cycle (ERC) for heating aims, power generation, and cooling aims, respectively. The Diesel engine is fed by different fuels and biofuels to drive the bottoming cycles. The Transesterification method has been used for biodiesel extraction from different oil-basis materials. The produced biodiesel supplied to the Diesel engine in different engine speeds and loads to evaluate the system performance from viewpoints of the energy and exergy. The highest generated power for the total system is obtained in the case of sunflower biodiesel blend and B10 sample as the fuel. The maximum overall system energy efficiency obtained when the canola B30 blend is applied in 100% load and 2400rpm. Based on the obtained results, the exergy efficiency considerably increases in the case of biodiesel, and diesel blends as the fuel compared to the pure diesel. Exergy efficiency was optimized for the proposed combined heating, cooling and power generation system at 100% load, 1700 rpm and B10 blend obtained from canola oil.