Common Heat Transfer Fluid Problems
| Problem | Cause | Consequence |
| Oxidative Degradation | -Exposure of Heat Transfer Fluid to air leads to an oxidation reaction that degrades the fluid over time.– Absence of blanketing with an inert gas (e.g N2,Ar) | – Increase in viscosity (decrease in heat transfer efficiency)– Increase in Total Acid Number (TAN). Leads to corrosion problems if moisture is present
– Fouling/Formation of sludge (fouling decreases heat transfer efficiency and increases maintenance costs) – Fluid discoloration See our recommendation on Oxidative degradation in the article, ‘Solutions to Heat Transfer Fluid Problems’ |
| Thermal Cracking | -Heating a Heat Transfer Fluid above its bulk temperature of the heat transfer fluid results in a cracking of the fluid. A rapid rise in burner/boiler temperature can also crack the fluid.– Low flow
– Improper flame impingement
|
– Decrease in viscosity, flash point, fire point and autoignition temperature (safety concern)– Carbon varnishes foul heat transfer surface
– Fluid has pungent/sharp smell See solution in the article, ‘Solutions to Heat Transfer Fluid Problems’ See our recommendation on thermal cracking in the article, ‘Solutions to Heat Transfer Fluid Problems’ |
| Contamination | – Pipe/vessel leaks may cause process to enter into the Heat Transfer Fluid causing/accelerating fluid degradation– Water may get into the expansion tank
– Poor drainage and flushing of degraded Heat Transfer Fluid before replacement with new fluid. |
-Rapid fluid degradation– Corrosion
– Pump cavitation (in a case where water vapor is converted to steam as temperature is increased) – There could also be adverse effects on fluid viscosity, volatility and heat transfer efficiency See our recommendations on fluid contamination in the article, ‘Solutions to Heat Transfer Fluid Problems’ |
Source: www.calderafluids.com