Medupi steam boiler plant situated in Limpopo supplies power at Lephalale area. A steam boiler plant consits of an economiser , evporator and a super heater , Steam is generated ata rate of 5.22kg/s at a pressure of 5000 kPa and 450degress. The feed water enetrs the economiser at 44 derees and the boilerr at 95degrees. The steam leaves the evaporator. 0.79 dry . The plant uses 850 kg coal/hour with caloric value of 83MJ/kg. Calculate

1.1) The heat transfer in the economiser

1.2) The heat transfer in the evaporator

1.3) The heat transfer in the superheater

1.4) The plant efficiency