A counterflow regenerator is used in a gas turbine power plant to preheat the air before it enters the combustor. The air leaves the compressor at a temperature of 350?C. Exhaust gas leaves the turbine at 700?C. The mass flow rates of air and gas are 5 kg/s. Take the cp of air and gas to be equal to 1.05 kJ/(kg K). Determine the required heat transfer area as a function of the regenerator effectiveness, if the overall heat transfer coefficient is 75 W/(m2 K).GIVENCounterflow air-to-gas heat exchangerEntering temperaturesTa,in = 350?CTg,in = 700?CMass flow rates: ma = mg = 5 kg/sSpecific heats: cpa = cpg = 1.05 kJ/(kg K) = 1050 J/(kg K)Overall heat transfer coefficient (U) = 75 W/(m2K)

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Gas Tah= 700°C Tan- 350°C Alr