Question

An Conference Center is to be air-conditioned for a seating capacity of 3200 people for the following outdoor and comfort conditions a) Outdoor design conditions = 35 °C, db and 65% R.H b) Indoor/return design conditions-26 deg C. db and 55% RH. c) Total sensible room load = 420,000 kJ/hr d) Total latent room load = 200,000 KJ/hr e) The rise in dry bulb temperature of the air inside the conference center is limited to 9 °C (i.e. the Supply air temperature should not be more than 9 °C below the indoor temperature) f) 75% of the room air is recirculated and mixed with 25% of fresh air. g) Assuming NO heat gain from the fan or duct Air conditioning is carried out through cooling and dehumidifying then reheating The Tadp (the apparatus dew point temperature) of cooling coil is 10 deg C. The system components diagram is shown in Fig 2 EXHAUST CONDITIONED ROOM OUTOOOR AIR CONDITIOWER HEATER & COOLER BLOWER OR DEHUMIDIFIER Figure 2 a) Sketch the process lines on a psychrometric chart. (With all the letter as named in Figure 2) b) Find quantity of air supply at outdoor air-condition in the unit of m3/person/min c) Find the capacity of refrigeration system in tons of refrigeration d) Find the capacity of the heating coil in KW e) Find the bypass factor of the cooling coil f) Find the mass flow rate of the coil condensatior g) What is the heating water mass flow rate in kg/s if temperature difference is 5 OC? Hint: Mark the State A for OA (outdoor air) , State B for RA (room air) and State C for MA (mixed-air). Draw the SHR line and then mark SA (supply air as State g) Draw the cooling process line (i.e. the coil SHR line). Then, find out the corresponding off-coil condition (state e) before the sensible heating process (State c and state d are the same as we assumed no heat released by the fan)

Answer 1

Sl Griven data 8s, totat Senstble head &s 4,00 k/h 420,000 3b00 116 66 k Ledent heat 4々a00,000nIhr 200,000 55-55 kuD 36o0 2 6 66t 5s.SS ATaiv inside ,9% maty -fresh 025 masy

Δ1, 35-26 :92 6s116 66k Nouw, mail 116.66 12-63 Kgls 0216)x 342 36 kglhr 『 0.25 x12-68。3-1부 kgls 11412 kg/hr ens? aa faia 1.225 k Supply percen nin mai-total 718 . 8ukg/min aus- 02 66 m min 3.861

116. 6b 30 21TR 3 86I Cooling Cof (a6-15) (35-15) 20