Engineers who developed refrigeration efficiency discovered, unlike water, liquid refrigerants, unlike other fluids that have a low surface tension. Fluids spread quickly into a sheet when coming into contact with a surface. For many industrial processes, it would be better if the fluids formed droplets that could roll or fall off the surface, then carry heat away with them. https://www.glewengineering.com/part-2-engineers-say-new-age-fridge-features-10-must-haves/
Slippery Surface
Sheets of liquid coat a surface, provide an insulating layer that inhibits heat transfer. Heat transfer, crucial to making these processes work efficiently. Heat transfer is enhanced when the liquid quickly forms droplets. Together they connect and grow , fall away under the force of gravity. Getting low-surface-tension liquids to form droplets. A serious challenge is getting them to shed easily. Fluids , such as those used in refrigeration systems, liquification, waste heat recovery. Distillation plants or materials such as methane in oil. Gas liquification, plants often have low surface tension compared to water. Meaning it is very hard to get them to form droplets on a surface. Instead, they tend to spread out in a sheet, known as wetting. https://www.glewengineering.com/semiconductor-industry-growth-continues/
Engineers Improve Heat Transfer
Promoting droplet formation, is possible to achieve a four- to eight-fold improvement in heat transfer. Condensation is just one part of a complex cycle, translating into an overall efficiency improvement of about 2 percent. https://www.energyvanguard.com/blog/plastic-film-might-replace-air-conditioner
Engineers Improve Fluid Repelling Effect
Fluid-repelling effect was enabled using a very thin solid coating, less than a micron thick (one millionth of a meter). Thinness is important to ensure that the coating doesn’t contribute to blocking heat transfer. Coating made of a specially formulated polymer, is deposited on the surface using a process called, initiated chemical vapor deposition (iCVD). Coating material is vaporized and grafts onto the surface to be treated, such as a metal pipe, to form a thin coating.
Engineers Improve iCVD Process Optimization
iCVD process was optimized by tuning the grafting of coating molecules onto the surface. Engineers develop refrigeration minimizing the pinning of condensing droplets and facilitate their easy shedding. The process could be carried out on location in industrial-scale equipment. Retrofitted into existing installations to provide a boost in efficiency. Process is “materials agnostic”, can be applied on either flat surfaces or tubing made of stainless steel titanium. Commonly used materials in condensation heat-transfer processes that involve these low-surface-tension fluids. https://www.inc.com/kevin-j-ryan/phononic-refrigerator-global-warming.html