Industrial Coolants and Its Uses
Coolant is that type of substance that is used for reducing or regulating the system’s temperature that comes in gas or liquid form. Few of the best coolants that can be used are those that are of high thermal capacity, non toxic, chemically inert, low cost, has low viscosity and neither causing or promoting corrosions to 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. This term covers cutting fluids too. As for the coolants, it can actually stay on its phase, gaseous or liquid and at times, it undergoes a transition with latent heat which then adds the cooling efficiency. Now say for example that the latter is put into use to achieve below ambient temperature, then it is known 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 being used as well 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.
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. Actually, carbon dioxide is also used for mixing it 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. The steam however could be used where there’s high specific heat capacity that’s required in gaseous form.
A popular type of coolant used is water. Its low cost as well as high heat capacity has made it ideal for heat transfer medium. Most of the time, technicians are combining it with additives like 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. Because of the low electrical conductivity of pure de-ionized water, it’s widely used for regulating the temperature on electrical equipment.