If the flue gases exiting the boiler are used to preheat the water fed to the boiler from a temperature of 28ºC to 90ºC and assuming:
• a mean specific heat capacity for water over this temperature range to be 4.2 kJ kg–1 K–1
• a mean molar heat capacity for the flue gases up to 300ºC to be 31 kJ kmol–1 K–1
• 10% of the heat required to heat the water is lost in the heat exchanger
• all water entering the system is converted to steam
Determine the final outlet temperature of the flue gas?
Further Data:
The flue gases produced are to be used to generate 5 bar steam from water at 90ºC
The total flow of flue gases is 1400 kmol h–1
