# How is heat exchanger duty calculated?

## How is heat exchanger duty calculated?

i.e. condenses.

- Heat Duty (Sensible heat – No phase change) Q = M * Cp * ∆T. Where;
- Heat Duty (Latent heat – Phase change) Q = M * λ Where;
- Heat Duty for Multiphase streams. If you have a stream where more than one phase exists then you can calculate the heat duty using the equation below: Q = Qg + Qo + Qw.

### How do you calculate steam consumption in a plate heat exchanger?

- cp = Specific heat capacity of the secondary fluid (kJ/kg K) or (kJ/kg °C)
- ms = Mean steam consumption rate (kg/s)
- hfg = Specific enthalpy of evaporation of steam (kJ/kg)
- cp = Specific heat capacity of the secondary fluid (kJ/kg °C)

#### How do you calculate plate heat exchanger?

Calculation method

- Heat load, Theta and LMTD calculation. Where: P = heat load (btu/h) m = mass flow rate (lb/h)
- Heat transfer coefficient and design margin. The total overall heat transfer coefficient k is defined as: α1 = The heat transfer coefficient between the warm medium and the heat transfer surface (btu/ft2 h °F)

**How is heat exchanger area calculated?**

ΔTm =

- ΔTm =
- = 94.9 °F. 0.10536.
- The preliminary area estimate of the heat exchanger can now be calculated as: A = Q / (U x ΔTm) =
- A = 2, 035, 000 Btu/hr.
- = 178.7 ft² (120 Btu/h.ft².°F).(94.9°F)
- The required mass flow rate of water can be calculated from Q = m.Cp. ΔTm: Rearranging:
- m = Q…… = Cp x ΔTm.
- m = (2,035,000 Btu/hr)

**How do I calculate heat exchanger size?**

## What is BTU formula?

A BTU is an abbreviation for British Thermal Unit, which is the amount of energy required to raise 1 pound of water 1 degree Fahrenheit at sea level. BTU = Flow Rate In GPM (of water) x (Temperature Leaving Process – Temperature Entering Process) x 500.4*Formula changes with fluids others than straight water.

### How do you calculate heat consumption?

Q = m*s*dT, where Q = heat, m = mass, s = specific heat, and dT is the change in temperature (T2 – T1). You can use this formula to calculate the specific heat. In the case of gases, just replace the mass by moles of the gas.

#### How do you calculate overall heat transfer coefficient in heat exchanger?

The overall heat transfer coefficient R = Resistance(s) to heat flow in pipe wall (K/W) Other parameters are as above. The heat transfer coefficient is the heat transferred per unit area per kelvin.

**How do you calculate heat exchanger efficiency?**

Calculating Heat Exchanger Efficiency

- Efficiency = Actual output / Output of the ideal system. Since we don’t have an ideal heat exchanger to compare with, we cannot use the traditional concept of efficiency for heat exchangers.
- Q = UA(FΔTlm)
- E = Q / Qmax.