A gas turbine operates with air with two stages of compression and two stages of expansion at 100 kPa and 178 C. This cycle uses a regenerator, reheating and intercooling.

The pressure ratio across each compressor is 4; 300 kJ/kg of heat are added to the air in each combustion chamber; and the regenerator perfectly operates while increasing the temperature of the cold air by 208 C. Calculate this system's thermal efficiency. Assume isentropic operations for all compressor and the turbine stages and use constant specific heats at room temperature. The properties of air at room temperature are Cp = 1.005 kJ/kg.K and k = 1.4