Free Heat Exchanger Duty Calculator

Calculate the thermal duty (heat transfer rate) of a heat exchanger from fluid flow rate, specific heat, and temperature change.

kg/s
kJ/(kg·K)
°C
°C

Heat Duty (Q)

836.00 kW

Heat Duty2,852,549 BTU/h

Heat Duty (Q) vs Mass Flow Rate (m)

Heat Exchanger Duty

The thermal duty Q is the rate of heat transfer between the hot and cold streams. It is calculated from the energy balance on one side of the exchanger.

Formula

Q = m × Cp × T_in - T_out

where m is the mass flow rate, Cp is the specific heat capacity, and the temperature difference is the change experienced by the fluid. At steady state, the duty calculated on the hot side must equal the cold side (energy balance).

Example Calculation

Water flowing at 5 kg/s is cooled from 80°C to 40°C.

  1. 01delta_T = |80 - 40| = 40°C
  2. 02Q = 5 × 4.18 × 40 = 836 kW
  3. 03In BTU/h: 836 × 3412.14 = 2,852,549 BTU/h

Frequently Asked Questions

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