Thermodynamic analysis of exhaust waste heat recovery from turbocharged HCCI engine fueled by wet-ethanol using an absorption refrigeration cycle (ARC)

Abstract This paper presents a thermodynamic study of the exhaust waste heat recovery from turbocharged Homogenous Charge Compression Ignition (HCCI) engine powered by wet-ethanol for a combined output of engine power and cooling system by using a LiBr-H2O absorption refrigeration cycle (ARC). For power production, an HCCI engine has been used, and an ARC driven by engine exhaust heat has been used as a bottoming cycle for refrigeration. While varying the compressor pressor ratio, compressor efficiency, and ARC generator temperature, the thermal and exergetic performance of the combined power and cooling cycle was investigated. The results showed that increasing the compressor ratio (2.25–3.75), and efficiency of the compressor (0.725–0.875), increases HCCI engine power and increases the cooling of the bottoming cycle. As a result, both thermal and exergetic efficiencies of the HCCI engine and combined cycle increase. In addition, as the temperature of the generator (361–385 K) rises, the ARC's thermal and exergetic COPs decreases.