Coolant is that type of substance that is used for reducing or regulating the system’s temperature that comes in gas or liquid form. 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.
While coolant is typically referred to HVAC and automotive applications, the industrial coolant is much more of a technical as it’s found in heat transfer fluid frequently used for low as well as high temperature for the manufacturing applications. At the same time, the term is used to cover cutting fluids. Coolants may stay on its phase, gaseous or liquid or, it may undergo a transition with latent heat adding to efficiency of cooling. When the latter is used to attain below ambient temperature, it is called automatically as refrigerant.
A common type of coolant in the market is air. Air cooling is making use of either forced circulation by using fans or convective airflow or otherwise known as passive cooling. 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. The hydrogen cooled turbo generators are at the moment most widely used electrical generator in big power plants.
The inert gases are being used as coolants for gas cooled nuclear reactors. The helium has low tendency of absorbing neutrons and becoming radioactive. Actually, carbon dioxide is also used for mixing it with AGR reactors and Magnox. In regards to sulfur hexafluoride however, this is utilized to insulate and even cool high voltage power systems; to give you examples, it can be switches, transformers, circuit breakers and so on. The steam however could be used where there’s high specific heat capacity that’s required in gaseous form.
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. Usually, it’s used with additives similar to 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. A similar coolant is betain but with an exception that it’s manufactured using pure plant juice. The pure de-ionized water is utilized to cool electrical equipment because of its low electrical conductivity.