1.5. A steam boiler plant consists of an economiser, evaporator, and a superheater. The steam is produced at a rate of 15000 kg/hr at 2500 kPa and 350 C. The feed water enters the economiser at 45 C and exits at 95 C. The steam leaves the evaporator 90% dry. The plant uses 1000 kg/hr of coal with a calorific value of 65 MJ/kg. Calculate: (i) Heat transfer in the economiser (5) (ii) Evaporator heat transfer