Multiple Expansion Reheating Gas Turbine for Cogeneration Plants

The following is a study of the feasibility of a cogeneration system characterized by a power unit with a multiple expansion reheating gas turbine. The "limit" specific cost of investment, calculated on the assumption of a non-profit making situation, of the additional electrical power obtainable in relation to the solution under reference, has been used to evaluate the financial advantage of the system. The limit value, within a defined list of tariff rates, will depend substantially on electrical efficiency which, in turn, will be affected by the quality of heat recovery, the degree of recombustion and the coefficient of heat itilization. The numerical results of the study show that, even in the unfavourable cases examined, these limit values for specific investment cost are sufficiently high to make them profitable against the likely industrial costs of a significantly large production series.