Enter the heat transfer coefficient, heat transfer area, inlet temperature, and outlet temperature into the calculator to determine the coaxial heat exchange.

Coaxial Heat Exchanger Formula

The following formula is used to calculate the total heat exchange of a coaxial heat exchanger. 

Q = U * A * LMTD
  • Where Q is the heat exchange rate (kJ/hr)
  • A is the total heat transfer area (m^2)
  • U is the overall heat transfer coefficient (kJ/(hr*m^2*C))
  • LMTD is the log mean temperature difference

To calculate the heat exchange rate of a coaxial heat exchanger, multiply the heat transfer coefficient by the area, then multiply by the log mean temperature difference.

What is a coaxial heat exchanger?

A coaxial heat exchanger is a vital component used in various industries to transfer heat between two fluids efficiently.

It consists of two concentric tubes, one placed inside the other, with the fluids flowing in opposite directions. The inner tube carries one fluid while the outer tube carries the other fluid. The separation between the tubes allows for the exchange of thermal energy without directly mixing the fluids.

The importance of a coaxial heat exchanger lies in its ability to enhance heat transfer efficiency. The concentric tube design maximizes the surface area available for heat exchange within a compact space, making it highly efficient.

By enabling the transfer of thermal energy between fluids, it plays a crucial role in various systems, including HVAC systems, refrigeration units, and industrial processes.

How to calculate coaxial heat exchange?

Example Problem:

The following example outlines how to calculate the heat exchange rate of a coaxial heat exchanger.

First, determine the area of heat transfer. In this example, the area is 2 m^2.

Next, determine the inlet and outlet temperatures. For this example, these are 50C and 40C respectively.

Next, using the inlet and outlet temperatures, calculate the log mean temperature difference. Using the calculated linked above, this is found to be: 44.81

Next, determine the overall heat transfer coefficient. This is determined to be 5 kJ/(h*m^2*c).

Finally, calculate the heat exchange rate using the formula above:

Q = U * A * LMTD

Q = 5 * 2 * 44.81

Q = 448.1 kJ/hr