Where are Industrial Coolants Used?
Coolant is a kind of substance that is either in gas or liquid form that’s being used to regulate or reduce temperature of the system. The best coolants you can get is something that have low viscosity, low-cost, chemically inert, non toxic, has high thermal capacity and not promoting or causing corrosion of the cooling system. Some applications need the coolant to be electrical insulator too.
When the term coolant is used, we often associate it to automotive as well as HVAC applications but industrial coolant is a lot different since it’s more of a technical aspect and used generally in low and high temperature manufacturing applications. At the same time, the term is used to cover cutting fluids. Coolants might be able to stay on its phase, gaseous or liquid or it can even undergo a transition with latent heat that adds to the efficiency of cooling. When the latter is utilized for achieving below ambient temperature, it’s automatically called as refrigerant.
Air is a very common form of coolant in the market. There are a couple of ways to which air cooling is used and it’s through passive cooling or also known as convective airflow as well as forced circulation by making use of fans. Hydrogen is used too for high performance gaseous coolant. The thermal conductivity is a lot higher compared to all other gases, it has low density and high specific heat density and as a result, low viscosity which is actually a benefit for rotary machines that are vulnerable to windage losses. Hydrogen cooled turbo generators are widely used for electrical generators in big power plants at the moment.
The inert gases are being used as coolants for gas cooled nuclear reactors. Helium has this low tendency to absorb neutrons and become radioactive. Carbon dioxide is actually used to be mixed with AGR reactors and Magnox. On the other hand, sulfur hexafluoride is used to cool and insulate some high voltage power systems like switches, transformers, circuit breakers and so on. Steam can also be used where there is high specific heat capacity required in gaseous form.
A very common type of coolant is water. It becomes ideal for heat transfer medium given the fact that it has high heat capacity plus, it is cost effective. It is usually used with additives such as antifreeze as well as corrosion inhibitors. In most cases, diethylene glycol, propylene glycol or ethylene glycol mixed in water is the components of antifreeze. Betain however is made using pure plant juice but is likely similar with water coolants. The pure de-ionized water is utilized to cool electrical equipment because of its low electrical conductivity.