Heat Exchanger Duty Calculator

Calculate heat exchanger duty, LMTD, and required area for oil/gas heating or cooling

Hot Side Temperatures

Temperature of the hot fluid entering the heat exchanger (heating medium such as steam, hot oil, etc.).
°F
Temperature of the hot fluid leaving the exchanger. Must be greater than cold fluid outlet.
°F

Cold Side Temperatures

Temperature of the cold fluid (e.g., crude oil) entering the heat exchanger.
°F
Desired outlet temperature of the cold fluid. Must be less than hot fluid inlet temperature.
°F

Flow and Heat Transfer Data

Mass flow rate of the cold fluid. For crude oil: multiply volumetric rate (bbl/hr) by density (~350 lb/bbl for typical crude).
lb/hr
Specific heat capacity. Crude oil: 0.40-0.55 BTU/lb-degF. Water: 1.0 BTU/lb-degF.
BTU/lb-°F
Overall U-value including fouling. Oil-to-oil: 40-75, Oil-to-water: 80-150, Steam-to-oil: 100-200 BTU/hr-ft2-degF.
BTU/hr-ft2-°F

Results

Heat Duty (Q)-MMBTU/hr
LMTD (Counter-Current)-°F
Required Heat Transfer Area-ft2
Hot Side Flow Required-lb/hr
Effectiveness-%
References & Formulas:
Q = m × Cp × (Tc,out − Tc,in)
LMTD = (dT1 − dT2) / ln(dT1/dT2) for counter-current
dT1 = Th,in − Tc,out; dT2 = Th,out − Tc,in
A = Q / (U × LMTD)

TEMA Standards. Kern: Process Heat Transfer. Perry's Chemical Engineers' Handbook.