A steady flow of 20 m3/s of moist air at TDB = 35iC, TWB = 25iC, 100 kPa (state 1) is dehumidified by first cooling it and condensing out moisture (state 2), then reheating it to 20iC and 50% R.H. (state 3).
(a) Calculate the initial specific humidity ù1, relative humidity ö1 and moist air enthalpy hA by using the equations developed last week. Compare these with the values read from the psychrometric chart. (b) Calculate the mass flow rate of dry air in kg/s.
(c) Sketch an outline psychrometric chart showing these three processes.
(d) Determine ù3 and the temperature T2 to which the air must be cooled using the psychrometric chart.
(e) Calculate the mass flow of water condensed in kg/s and the heat transfer rate in the cooler (1 - 2) in kW. Use values from the psychrometric chart. Assume that the condensate leaves at T2.