Opportunities with alternative refrigerants

Abstract

Due to environmental concerns, a new generation of refrigerants has been introduced. The new fluids perform well, but because of their remaining global warming potential they are still under scrutiny internationally and may be eliminated in the future. Research is underway to develop so-called 'natural fluids' into the final solution to the quest for the ultimate refrigerant. The primary candidates are carbon dioxide and hydrocarbons such as propane and ammonia. Each fluid comes with its own set of challenges. Carbon dioxide requires a transcritical cycle, which reduces its efficiency but, on the other hand, may provide secondary uses due to its high temperature level waste heat. It is under consideration for automotive and military applications. Carbon dioxide hot water beat pumps have been introduced in the market in Japan. Propane performs very well, but it is flammable and thus considered a safety hazard. Ammonia is widely used in large refrigeration plants, although it is toxic and flammable. Its stinging odor warns of any leaks long before any dangerous concentrations are obtained. This presentation will provide an overview of these existing and emerging refrigerants and the opportunities and challenges they provide.