The ORC power unit driven by the exhaust gas heat of a gas turbine power set and the system power output as influenced by the ORC characteristic parameters

The authors presented problems related to utilization of the waste heat, carried by the exhaust gases of the gas turbine power set, with a goal to achieve an additional electricity generation. A relevant solution is then discussed, in which the gas turbine power set is thermally coupled with an ORC power unit that uses organic fluids as its working medium. The solution offers an increase in the electricity generation efficiency and in the electric power output. The rate of the waste heat utilization, converts directly into the degree of the increase in the generation efficiency and power output, and depends on the ORC characteristic parameters. Effects on the thermally coupled power system performance of several ORC parameters and of possible ORC cycle solutions were then analysed. Variations in the organic vapour pressure and temperature at the ORC turbine inlet, in the steam condensation temperature, and for four different organic fluids (benzene, cyclohexane, decane and toluene) were examined. With account to the varying parameters calculations of the simulated combined power systems were performed. As result, diagrams to illustrate the influence of individual ORC parameters and of the type of organic fluid on the combined power system performance (efficiency, power output) were elaborated.