A boiler with superheater generates 6,000 kg/h of steam at 1·5 MN/m², 0·8 dry at exit from the boiler and at a temperature of 300°C on leaving the superheater. The feed water temperature is 80°C and the overall efficiency of the combined boiler and superheater is 85%.
Determine the following, stating any assumptions made:
(a)The amount of fuel, of calorific value 30 MJ/kg, used per hour.
(b)The equivalentevaporation from and at 100°C for the combined unit.
(c)The heating surface required in the superheater if the rate of heat transfer may be taken as 450,000 kJ/m² of heating surface per hour.
Describe briefly that advantages you would expect to be gained from the following in a steam generation plant:
(d)A superheater.
2(e)An economiser.
