A surface condenser is required to deal with 15 000 kg/h wet steam. Wet steam temperature is 37 C and enters the condenser with 0.95 quality (dryness fraction is 0.95). The water used for cooling has the following data:
 Inlet pressure 1.20 bar, inlet temperature 7 C
 Outlet pressure 1.013 bar, outlet temperature 22 C
Calculate the flow rate of cooling water and tube surface of the condenser. Assume that the cooling water velocity through tubes is 1.5 m/s
Inputs 
Units 

Wet steam inlet temperature 
37 
C 
Steam quality 
0,95 
. 
Cooling water inlet temperature 
7 
C 
Cooling water inlet pressure 
1,2 
bar 
Cooling water outlet temperature 
22 
C 
Cooling water outlet pressure 
1,013 
bar 
Steam mass flow 
15000 
kg/h 
Cooling water speed 
1,5 
m/s 
Outputs 
. 
. 
Wet steam pressure 
0,06274 
bar 
Enthalpy of steam at inlet 
2448,28 
kJ/kg 
Entropy of condense 
154,92 
kJ/kg 
Rejected heat/hour 
34400441,72 
kJ/h 
Rejected heat/second 
9555,68 
kJ/s = kW 
Enthalpy of water at inlet 
29,53 
kJ/kg 
Enthalpy of water at outlet 
92,31 
kJ/kg 
Water mass flow 
547885,14 
kg/h 
The overall heat transfer coefficient can be calculated according to BEAMA or HEI standards.
BEAMA: British Electrical and Allied Manufacturers Association
BEAMA publication on the recommended practice for design of surface type steam condenser
HEI: Heat Exchanger Institute
HEI standards for steam surface condensers
Outputs 
Unit 

Heat transfer coeff.(BEAMA) 
2,95235 
KW/m2,K 
Logarithmic mean temp. diff. 
49,83 
degree K 
Required area 
64,96 
m2 
If we use the less conservative HEI method we obtain the following:
Outputs 
Unit 

Heat transfer coeff.(HEI) 
3,60991 
kW/m2,K 
Required area 
53,12 
m2 