Different Uses of Industrial Coolants
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 of its applications require the coolant to be electrical insulator as well.
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.
A common type of coolant in the market is air. Air cooling is using either forced circulation using fans or, convective airflow otherwise known as passive cooling. Hydrogen is being used as well for high performance gaseous coolant. Thermal conductivity is higher in comparison to other gases because it has low density and high specific heat density and for that, it’s low viscosity that is a big benefit for systems using rotary machines that are susceptible to windage losses. Hydrogen cooled turbo generators are widely used for electrical generators in big power plants at the moment.
As for nuclear reactors that are gas cooled, what is used in this purpose is inert gases. Helium has this low tendency to absorb neutrons and become radioactive. Carbon dioxide is actually used to be mixed with AGR reactors and Magnox. Sulfur hexafluoride on the other hand is being used for cooling and insulating high voltage power systems similar to switches, transformers, circuit breakers and so on. Whenever there is a need for high specific heat capacity in gaseous form, then expect that steam is what used.
Water is another common type of coolant. 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. The antifreeze is a solution made from suitable organic chemical oftentimes diethylene glycol, propylene glycol or ethylene glycol in water. Betain however is made using pure plant juice but is likely similar with water coolants. Because of the low electrical conductivity of pure de-ionized water, it’s widely used for regulating the temperature on electrical equipment.