Modeling and analysis of total site cogeneration of heat and power from an exergoeconomic approach in a 100MW case study

In this paper, modeling and analysis of equipment arrangement from an exergoeconomic approach to produce required heat and power of a total site is determined. By using a modified Iterative Bottom-to-Top Model (IBTM) as a new cogeneration targeting method, cogeneration of heat and power potential to design utility system of a total site is estimated and fit to it, superheated temperature of steam levels, power generation of steam turbines between levels, flow rate of passing steam through turbines, amount of boiler heat load and boiler required fuel flow rate are calculated. First, different scenarios of steam turbines arrangements are introduced that are investigated from exergoeconomic approach. Also in suggested plans to produce extra power in case study, gas turbine system has maximum exergy efficiency, minimum exergy destruction, minimum total capital cost rate and exergy destruction cost rate rather than condensing turbine plan. Hence, the selected scenario of back pressure steam turbines arrangement beside the gas turbine system were introduced as the optimum system of heat and power cogeneration system in total site for this case study from an exergoeconomic approach.