Common design calculation formula
Total heat: unit: kcal / h
1RT=3.5kw
1P=2.324kw
1kw=860kcal/h
1k=4.27J
1. Air cooling
QT=QS+QL
QT=0.24*&*L*(h1-h2)
QT ---- total heat of air
QS ---- sensible heat of air
QL ---- latent heat of air
&----- the specific gravity of air is 1.2 kg / m3
L ----- total indoor air supply volume m3 / h
H1 - initial enthalpy of air kJ / kg
H2 ---- final enthalpy of air kJ / kg
2. Sensible heat
Unit:kcal/h
QS=Cp*&*L*(T1-T2)
CP -- specific heat of air, 0.24kcal/kg
T1 -- initial dry bulb temperature of air
T2 - final dry bulb temperature of air
3. Latent heat
Unit:kcal/h
QL=600*&*L*(W1-W2)
W1 -- initial moisture content of air, kg / kg
W2 -- final moisture content of air, kg / kg
4. Chilled water volume
Unit:L/S
V1=Q1/4.187*(T1-T2)
Q 1 -- refrigerating capacity of main engine (kw),
T1-T2 ---- inlet and outlet water temperature difference of main engine
5. Cooling water volume
Unit:L/S
V2=Q2/4.187*(T1-T2)
Q2=Q1+N
Q2 -- cooling heat kw
T1-T2 ----- inlet and outlet water temperature of main engine cooling water
N ----- power consumption of refrigeration unit kw
6. Motor full load current calculation
Unit:A
FAL=N/1.732*U*COS@
7. Fresh air volume
Unit:M3/H
L0 =n*V
N ----- room ventilation rate
V - room volume
8. Air supply volume
Unit:M3/H
L= QS/ Cp*&*(T1-T2)
QS ---- sensible heat kcal / h
CP -- specific heat of air, 0.24kcal/kg
T1 -- initial dry bulb temperature of air
T2 -- final dry bulb temperature of air
&----- the specific gravity of air is 1.2 kg / m3
9. Fan power
Unit:KW
N1=L1*H1/102*n1*n2
L1 ---- fan air volume (L / s)
H1 ----- fan air pressure (mh2o)
N1 ---- fan efficiency
N2 - transmission efficiency, 1 for direct transmission; 0.9 for belt drive
10. Pump power
Unit:KW
N2=L2*H2*r/102*n3*n4
L2 ---- water flow velocity (L / s)
H2 ---- water pump head (mh2o)
N3 ----- pump efficiency = 0.7 ~ 0.85
N4 ----- transmission efficiency = 0.9 ~ 1.0
R - specific gravity of liquid (specific gravity of water is 1kg / L)
11. Pipe diameter
Unit:mm
D = 35.68 * root sign L2 / V
L2 ---- water flow velocity (L / s)
V ----- design flow rate of water (M / s)
12. Air humidification
Unit:g
R=LX*1.3*(h1-h2)
LX ---- fresh air volume (m3 / h)
H1 - enthalpy value under indoor design temperature
H2 ---- enthalpy value under outdoor minimum state (check enthalpy moisture diagram)
13. Equipment air volume design
(estimate)
[ ρ (equipment power) * 860 * 0.8/0.29 (specific heat of air) / 5 (temperature difference)] + Q1 + Q2
Q1 ---- air volume required for latent dispersion of people
Q2 ---- air volume required by the building
Ventilation consumption
People indoors need 30 CMH (m3 / h) / person of fresh air per hour
Number of air changes required in the city / hour
Residential (living room): 1-3 times,
Residential (bedroom): 1-2 times
School (classroom): 6 times,
School (Library): 8 times
Theater: 5-8 times,
Office: 6-10 times,
Hospital: 2 times
Shopping mall (shop): 6-10 times,
Restaurant (canteen): 6-10 times,
Song and dance hall (nightclub): 7-20 times
Hotel (Auditorium): 6-12 times,
Hotel (kitchen): 20-60 times,
Hotel (room): 1-2 times
Hotel (toilet): 5 times
Please feel free contact with us .
Company :Guangdong Head-Power Air Conditioning Co.,Ltd
Contact person :Cindy