Medupi steam boiler plant situated in Limpopo supplies power at Lephalale area. A steam boiler plant consists of an economiser, evaporator and a superheater. Steam is generated at a rate of 5.22 kg/s at a pressure of 5 000 kPa and 450C. The feed water enters the economiser at 44C and the boiler at 95C. The steam leaves the evaporator 0,79 dry. The plant uses 850 kg coal/hour with a calorific value of 83 MJ/kg. Calculate: 1.1. 1.2. The heat transfer in the economiser. The heat transfer in the evaporator. The heat transfer in the superheater. The plant efficiency. (4) (3) (3) (3) 1.3. 1.4