| |
| |
| |
Sample 1 |
| |
| Design Step 3: |
| Now we must find air mixture temperature & humidty of
supply air . |
| |
| Room air:22'C ,%50 rH |
| Outside air:-12'C ,%90 rH |
| |
 |
| |
Connect point 1 and point to with a line. |
| Most simple method is measure lengt of line and find middle
<5> of line for these sample. |
| Absolute humidity of mixture is 4.8 g/kg |
| Absolute humidity of room is 8.2 g/kg |
| |
| Mixture air : 5'C ,%90 rH |
| |
| Because of humidity difference we must supply water to air
for increasing humidity |
| W=m*(w2-w1) |
| W=Water quantity in kg |
| m=Air Mass Quantity in kg |
| m=V*q |
| V=Air SupplyAmount in m3/h |
| q=Air Density in kg/m3 :1,2 kg/m3 |
| m=10,000*1,2=12,000 kg |
| w2:Room air absolute humidity:8,2 g/kg |
| w1=Outside air absolute humidity:4,8 g/kg |
| |
| W=12000 (8.2-4,8)=40800 gr/hr=40,8 kg/hr |
| We must supply 84 kg/hr of water to supply air |
| |
| |
| After humidifier air will enter to heat exchanger.We can't
control exit humidity of air after humidifier. |
| We accept exit humidity after humidifier as %90 <4> |
| |
| |
| |
| Air in wet type humidifier (air washer ) will follow wet
bulb line.(Wet bulb will be constant ) |
| |
 |
| |
| From chart we see that we need and heat exchanger before
humidifier . |
| |
| |
| |
| Design Step 4: |
Required Heating Capacities. |
| |
| .4.a-Heating Coil Capacity (from mixture air to humidifier) |
| Formula: Q=m*C*DT |
| Q1=10,000*1,2*0,24*(21-5)=55,296 kcal/h |
| |
| .4.b-Reheater ,Heating Coil Capacity (from exit of humidifier
to supply) |
| Formula: Q=m*C*DT |
| Q2=10,000*1,2*0,24*(39,3-13))=75,744 kcal/h |
| |
| Total required heat capacity of air handling unit |
| Q=Q1+Q2=55,296+75,744=131,040 kcal/h |
| |
|
| |
| Back |
| |
