Thermodynamic Analysis of an Organic Rankine Cycle for Waste Heat Recovery from an Aeroderivative Intercooled Gas Turbine

This paper presents a study of an Organic Rankine Cycle combined with an intercooled gas turbine: thermodynamic analyses are carried out using four different organic fluids (toluene, benzene, cyclopentane and cyclohexane). Organic Rankine Cycle can be combined with a gas turbine through a diathermic oil circuit in order to convert gas turbine waste heat into electrical power: ORC can be a promising choice for waste heat recovery at low/medium temperatures. An intercooled gas turbine is characterized by low exhaust temperature, and the Organic Rankine Cycle, that can work with lower temperature respect to a Rankine cycle, can be an interesting solution to improve the efficiency of the power plant. In an intercooled gas turbine with high pressure ratio, waste heat can be recovered from exhaust gas and also from the intercooler: air temperature exiting from the first compressor is about 160-220°C and it is generally cooled by water. This waste heat can be recovered by an Organic Rankine Cycle to convert the low-temperature heat source into mechanical energy and increase the global power plant efficiency.