# How is heat exchanger duty calculated?

## How is heat exchanger duty calculated?

i.e. condenses.

1. Heat Duty (Sensible heat – No phase change) Q = M * Cp * ∆T. Where;
2. Heat Duty (Latent heat – Phase change) Q = M * λ Where;
3. 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?

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

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

Calculation method

1. Heat load, Theta and LMTD calculation. Where: P = heat load (btu/h) m = mass flow rate (lb/h)
2. 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 =

1. ΔTm =
2. = 94.9 °F. 0.10536.
3. The preliminary area estimate of the heat exchanger can now be calculated as: A = Q / (U x ΔTm) =
4. A = 2, 035, 000 Btu/hr.
5. = 178.7 ft² (120 Btu/h.ft².°F).(94.9°F)
6. The required mass flow rate of water can be calculated from Q = m.Cp. ΔTm: Rearranging:
7. m = Q…… = Cp x ΔTm.
8. 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

1. 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.
2. Q = UA(FΔTlm)
3. E = Q / Qmax.