A Comparison of the Predicted and Measured Thermodynamic Performance of a Gas Turbine Cogeneration System

The thermodynamic performance of a gas turbine cogeneration system is predicted using a computer model. The predicted performance is compared to the actual performance, determined by measurements, in terms of various thermodynamic performance parameters which are defined and discussed in this paper. These parameters include the electric power output, fuel flow rate, steam production, electrical efficiency, steam efficiency, and total plant efficiency. Other derived parameters are the net heat rate, the power-to-heat ratio, and the fuel savings rate. This paper describes the cogeneration plant, the computer model, and the measurement techniques used to determine each of the necessary measurands. The predicted and the measured electric power compare well. The predicted fuel flow and steam production are less than measured. The results demonstrate that this type of comparison is needed if computer models are to be used successfully in the design and selection of cogeneration systems.