Gas Turbine Direct Integration in the Context of Pinch Technology

Abstract

Gas-turbine-based cogeneration systems have been widely used in different applications in recent years. Although the most common method of using gas turbine exhaust energy is through the generation of steam in a heat recovery boiler, there are some applications where the exhaust energy has been directly used for drying or process fluid heating. In this work, direct integration of a gas turbine with a process was fully investigated in the context of pinch technology. This investigation includes simple gas turbine and gas turbines equipped with recuperator and afterburner. It was found that the best thermodynamic efficiency in a direct gas turbine system is achieved when two conditions are met: first, turbine inlet temperature is maximized, second, optimum pressure ratio is that which yields the maximum specific network. Two total cost optimization methods were also introduced. The first method is based on the assumption that power produced equates to power demand. In the second approach the power export opportunity was also considered. Finally, illustrative examples have been presented to show how approaches can be applied in practice.