A steam boiler at a power plant station consists of an economiser, an evaporator and a super heater. Steam is produced at a rate of 4 000 g/s at 3.1 MPa and 300°C. The feed water enters the economiser at 37°C and exits at 82°C. The steam leaves the evaporator 80% dry. The plant uses 800 kg/h of fuel with a calorific value of 60 MJ/kg. Calculate: a) The heat transfer in the economiser. b) The evaporator heat transfer. c) The heat transfer in the superheater. d) The plant efficiency. e) Equivalent evaporation from and at 100°C. 635 (9) (3) (5) (3) (3) [23 marks]