The fluids designed to work in heat transfer applications at high temperatures (around 400ºC) are generally based on mixtures of aromatic organic compounds.
The optimum characteristics for this type of fluid are:
- Proper function under extreme temperature conditions
- Excellent stability against thermal degradation
- Low hydrogen permeation at high temperatures to maintain the vacuum in the installation
- Good pumpability at low temperatures
- Low freezing point
One of the fluids most widely used in this type of installation consists of a binary blend of diphenyl ether and biphenyl, each at different percentages:
- Diphenyl ether
- Biphenyl
