Question

15- For ventilation purposes in a factory 3400 CMH of outside air must be handled. • The air condition inside the factory [21°C DBT, 15°C WBT] • The outside air condition [10°C DBT, 5°C WBT] • The sensible heat loss from the factory [54,000W] • The latent heat loss from the factory [6,000W] The supply air Temperature [38°C] After mixing process the air passes through heating coil then air washer. Calculate the following: a) Draw the psychometric cycle and line diagram. b) The quantity of air supply CMH c) The heater capacity kW d) Amount of make-up water L/min Repeat the problem if using steam humidifier.

Answer 1

sol Given data CMH = 3400 milhr Air condition inside the factory DBT, = 2100 WBT, = 15°C outside Air condition DB T2 = 10°c WB T₂ = 5°c Sensible heat loss - 5400old Latent heat loss – 6,000k! Supply air Temperature Tair = 380 Psychrometric cycle and Line diagram h, espolky 39 kJ/kg P ↑ humidity WBT 2158 h2 = 16 kilkg - - - - 0.0075 kg / kg dry air - - - - w = 0.004 4 kg / kg dry air WB T = 5 W₂ = 0.00 - - - - - - - DB T2 = 10 c DBT, = 21°c Dry bulb temperature

h = 39 kJ/kg , W, 0.0076 kg / kg of dry air 1.2 0.84 m²/kg I b. mas flow of air ma = CMH ma & 3400 0.84 ma = 4047. ma = 67.4603 Kolmin Quantity of air Supply Cont ma 67-4603 theating coil capacity - ma (h. he] = 67:468[39-16] - 1551.58 kJ/min - 25.859 khi . Heating capacity 25.899 kW

& Capacity of humidifier - ma [wr-we] • 64.460370.0076 -0.0042] = 0.21587 kg/min - 12.952 kg hr Amount of make-up water & 12.952 kg/hr