This is problem 8-7 from El-Wakil’s Powerplant Technology book-- air at 14.696 psia, 40 degF, and with 65 percent relativehumidity enters the compressor of a gas turbine cycle. Thecompressor and turbine have the same pressure ratio of 6 andpolytropic efficiencies of 0.8 and 0.9, respectively. Water at 60degF is injected into the compressor exit air, saturating it.Calculate (a) the air temperature after water injection (b) thepercent increase in mass flow rate due to water injection, (c) thecompressor work in Btus per pound mass of original air, and (d) thecompressor work if water is injected during the compression processto the same temperature as (a), in Btus per pound mass of originalair. Use a constant cp = 0.24Btu/lbmdegRankine.
