Feasibility? “Not feasible,” he whispered. “You’d need an infinite heat exchanger surface area and a miracle.”
He had solved thirty-two problems on regenerative cycles, reheat factors, and nozzle efficiencies. But this one was different. It described a combined cycle plant: a gas turbine topping a steam turbine, with an intercooler, reheater, and a heat recovery steam generator. The data was messy—inlet temperatures, pressure ratios, isentropic efficiencies, pinch points. And at the bottom, a deceptively simple question: “Determine the net work output and thermal efficiency. Comment on the feasibility of the cycle.” Steam And Gas Turbine By R Yadav Pdf 133 HOT
He wrote in the margin: “Cycle violates pinch point constraint. Gas outlet temperature after HRSG (calculated as 85°C) is below steam saturation temperature at 60 bar (275.6°C) plus minimum ΔT. Physically impossible without cryogenic intervention. Efficiency drops to ~52% with realistic pinch.” Feasibility