An improved cogeneration feasibility assessment program with combustion turbine applications

An interactive cogeneration modeler has been developed. This computer program simulates hourly operation of thermal plants with and without a proposed cogeneration system and compares them economically. The modeler has general applicability to natural gas fired thermal hosts. Up to 60 day types of electrical and thermal energy use profiles are allowed, loaded directly from a spreadsheet. These profiles may include up to two thermal streams, ambient temperature, fuel use, and electrical loads. Site information may include up to two existing thermal plants, two electrical utility rate schedules, and an operating schedule. Cogeneration systems that can be modeled include combustion turbines and reciprocating engines with heat recovery and optional duct firing, and back pressure steam turbines. All prime movers include off-design operating characteristics. Simulation outputs include hourly, monthly and life-cycle data for base case and proposed cogeneration systems. Hourly energy flows are presented in tabular and graphic formats. Life-cycle cash flows include effects of interest rates, inflation, and energy rate escalation