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Counterflow heat exchanger calculator
Calculate the steady heat transfer rate of a single-pass counterflow exchanger from UA, stream heat capacity rates and inlet temperatures. Choose input units and calculate one value within the stated conditions.
Inputs
Calculations run in this browser. Scientific notation such as 1.2e-3 is supported. Do not group thousands.
Result
Heat transfer rate Q̇
Enter values and select Calculate.
Q̇ = ε Cmin (Th,in − Tc,in); NTU = UA/Cmin; Cr = Cmin/Cmax; ε = [1 − exp(−NTU(1−Cr))]/[1 − Cr exp(−NTU(1−Cr))]; Cr = 1: ε = NTU/(1+NTU)
Assumptions
Required: ideal single-pass counterflow, steady operation, constant UA and heat capacity rates, and external insulation. Excluded: phase changes, axial conduction and heat loss. The hot inlet temperature must be at least the cold inlet temperature. Heat capacity rate is mass flow rate times specific heat at constant pressure, in W/K.
Displayed values are floating-point approximations. Design safety factors and unprovided error contributions are not calculated.
Formula references and credits
NaNa Lab created the code, descriptions, icons and preview images. Text, figures and code from the linked references have not been reproduced.
Physical constants: NIST / CODATA 2022. The values of μ₀ and ε₀ are measured recommendations, not exact defining constants. Values and precision notes are in the source record.
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