Heat transfer fluid is divided into mineral oil and synthetic fluid based on different manufacturing process and into liquid phase fluid and gas phase fluid based on diverse operating form.

Synthetic heat transfer fluid is manufactured through chemical synthesis and has certain chemical structures and names. According to the different components, synthetic fluids are mainly divided into hydrogenated terphenyl, isopropyl biphenyl, alkyl biphenyl, biphenyl diphenyl ether, diaryl alkanes, and benzyl toluene types. Every fluid has unique physical and chemical properties and different maximum operation temperature. when using the improper fluid, fluid early degradation and short service life, pipeline jam, fluid low temperature solidification and even system explosion will occur.

How to select and use right synthetic heat transfer fluids?

Higher Maximum Operation Temperature

The maximum operation temperature is the vital indicator of heat transfer fluid and decided by its chemical structure, purity, process temperature and other heat exchanging facility conditions. Fluid starts to degrade when the operating temperature is 50℃ below its maximum operation temperature and the thermal degradation rate shows the exponential relationship with the system temperature increasing.

Synthetic fluid with higher maximum temperature has low degradation rate, longer service life, efficiently decreasing the frequency of system fluid change and pipeline cleaning, which has better cost performance.

Fluid minimum operation temperature means the fluid status in cold condition. Lower minimum operation temperature makes system startup easily in cold areas.

Temperature Control Accuracy

Features of liquid phase heat transfer are low vapor pressure, high safety performance and easy to use. Liquid phase pattern transfers the fluid sensible heat and causes fluid temperature fluctuation and differences. Gas phase pattern transfers the fluid latent heat and generates stable and constant heating temperature, which is suitable for high demand of temperature control accuracy and temperature sensitive material heating conditions.

Proper Fluid Viscosity and Pour Point with High Boiling Point, Flash Point and Spontaneous Ignition Point

Low pour point represents fluid good low temperature performance. But fluid with low pour point also has low boiling point and high saturated vapor pressure. Therefore, it is usually to use a fluid with pour point that is 10-15°C higher than the ambient temperature. Flash point and spontaneous ignition stand for fluid safety performance. Fluid with high flash point and high autoignition point should be selected when other technical indicators are similar.

High heat conductivity coefficient brings high thermal efficiency.

Lower Contents of Carbon Residue, Ash, Moisture and Acid value

Carbon residue, ash content, moisture content and acid value represent fluid refined degree and purity. Higher purity means stable chemical structure and longer service life. Lower contents of sulfur, chlorine and acid mean less corrosions to system pipeline.

Beside above suggestions, fluid cost performance should also be considered when selecting fluid. Product quality and technical support are considered when prices are similar and cost performance is considered when the fluid qualities are similar.