Thermodynamic analysis of an in-situ cogeneration plant

This paper presents thermodynamic analysis and modelling of a cogeneration plant at a local hospital consisting of two 1.9 MW natural gas fired turbocharged spark ignition internal combustion engines. Heat is recovered from the exhaust, jacket water, and inlet charge coolers. Extensive experimental data on the performance of the plant was collected during July 2005. The control volume approach was followed to model the cogeneration plant and predict the energy flows and system performance parameters. Engine operation was simulated by two different approaches: one by the variable specific heat Otto cycle and the other by obtaining empirical engine characteristic curves. Simulated results were compared with the actual plant operation. The paper provides details of the modelling, measurements, performance, and simplified economic analysis of the cogeneration plant.