Energy and Exergy Analysis of Diesel Engine Powered Trigeneration Systems

This article presents the thermodynamic analysis of diesel engine powered trigeneration system considering the actual engine data of 200 kVA engine systems. Trigeneration systems considered for analysis comprises of a diesel engine integrated with absorption chillers. For better thermodynamic performance of a trigeneration system for cooling applications, absorption chillers integrated with engine systems should accept the heat energy at almost the same temperature at which it is available. With this consideration two trigeneration systems are examined. System one uses low grade heat energy recovered from engine jacket water with single effect chiller and high grade heat energy of exhaust gases in double effect chiller. System two combines recovered energy for use in a single chiller. Analysis of such trigeneration configurations cannot be based on first law analysis alone. This paper through an energy and exergy analysis of a trigeneration system under cooling mode, recommends the use of a trigeneration system with two chillers over a trigeneration system with single chiller. Operating the trigeneration system near the rated capacity of engines improves its energetic as well as exergetic performance. Though the initial cost of a trigeneration system with two chillers is more than the one with single chiller, life cycle costing analysis reveals the former is attractive even on economic basis.