Heat Exchanger Effectiveness
Heat Exchanger Effectiveness
Effectiveness compares the actual heat transfer to the maximum possible, rating how good a heat exchanger is independent of size.
For the hot stream, ε = (T_hi − T_ho)/(T_hi − T_ci). where T_hi, T_ho are the hot inlet and outlet and T_ci the cold inlet temperatures.
Inputs
T_hi := 90 degC=363.15 K
T_ho := 55 degC=328.15 K
T_ci := 20 degC=293.15 K
Form the actual-over-maximum temperature ratio.
eps := (T_hi - T_ho)/(T_hi - T_ci)=0.5
Results
An effectiveness of 0.5 means the exchanger achieves half the thermodynamically possible heat transfer. Higher values need more area or better flow arrangement.
Assumptions & limitations
- Minimum heat-capacity stream is the hot one (here).
- Steady flow.
- No losses to surroundings.