Question

Problem 2 (30 pts): For the air-conditioning system shown below in which atmospheric air is first heated and then humidified with a steam spray, determine the required heat transfer rate in the heating section and the required steam temperature in the humidification section when the steam pressure is 1 MPa. Heating fluid Steam, P-1 MPa Throttle Atmospheric O4 In air T, -5°C Pi - 100 kPa T3 -25°C 0,= 90° To= 24°C P,- 100 kPa V ,- 60 m/min 0 ,- 45

Answer 1

Pigi - 3 of and Peat 5c = 0.87 kPa R, 0.9xPvg 0.783 kPa W, 0.622 Pvc 4.90881x10 rolig PE- Pui +W, « bg (T) = (1.005 x 5) + ( 41.90871 x 10°*2510.6 ho GTi hi 11.35 kuling We W2 36.61 kali kolky 11 3.17 kPa puso 11 1.4265 kPa b = 1.005 x 24) +(4.9087x 162 2548- A Pat 65°c) Pus 9.0012 x 10 Pe - Puz (1.005 x 25) +(9.0012* Puz = 0₂ 0.45 x 3.167 = -3 Wz Puz 0. 622 3= 48.05 kolkig ha in [bb.) x 103 x 2544-2 By energy balance, required heat hansker in heahing section 100 x 60 75.2 Kyle 1448.81 kJ - 0.287x [27345) 75.2* | 36. 36.61 – 17.35) min (Coun) healing Section ha bulanu, a bs x w 36.6 .3 hs By energy bet ma ma [bs-ba) * in [Ws - w) xbs = m ( b ha 9.0012x10 (419.05 .61) 4.9087x10 2794.93 kolky Golbalpy of steam, for P= Impa & bs=2794.93 kulkg, from steam tables I ~ 1870 Temperature of steam h,