Analytical Models for Energy Audit of Cogeneration Plant

The energy losses and mismanagement can degrade the performance of the cogeneration plant; as well as increasing the economical cost of energy usage. Energy analysis models can be used as an effective mean for energy audit and management of the cogeneration plant. This paper presents the development of analytical models for energy audit of a cogeneration plant. Most of the energy losses occurred in a cogeneration plant are due to the imbalances of energy in the sub-systems of the plant. An analytical tool is developed and written in a computer program using the available specifications of component from an existing cogeneration plant. Actual operating data of the plant is used to verify the models and the energy utilization of the plant. Comparison between the actual operation performance and the optimum operating conditions provides means to improve the real time performance of the overall plant. The sub-systems in the cogeneration plant analyzed are, gas turbine engine, heat recovery steam generator, and steam absorption chiller. Implementation of the analytical tool found that energy loss in gas turbine engine can be minimised by changing the inlet air temperature and air mass flow rate.