Trade-offs in refrigerant selections: past, present, and future

The consequently development of refrigerants Chronological assessment

“…With a few exceptions, the efficiency gains achieved in machinery using the alternative refrigerants derive primarily from improvements in equipment design rather than the properties of newer working fluids. Simply put, better optimization with the old refrigerants would have yielded even higher efficiency in most cases, and the alternative refrigerants reduce margins for further product efficiency improvement (Calm and Didion, 1997). Third, none of the current or candidate refrigerants are ideal, and future discovery of ideal refrigerants is extremely unlikely (Calm and Didion, 1997).…”

“…Simply put, better optimization with the old refrigerants would have yielded even higher efficiency in most cases, and the alternative refrigerants reduce margins for further product efficiency improvement (Calm and Didion, 1997). Third, none of the current or candidate refrigerants are ideal, and future discovery of ideal refrigerants is extremely unlikely (Calm and Didion, 1997). The intensifying constraints force new compromises among different environmental,…”

“…While all refrigerants theoretically can reach similar efficiencies with sufficient cycle modification and optimization (Domanski et al, 1994;Domanski, 1995), each element of added complex-ity increases costs, refrigerant charge (amount), the potential for leaks, and thermodynamic irreversibility's and decreases reliability (Calm and Didion, 1997). Hence, refrigerants with high efficiencies in simple cycles have an inherent advantage to improve efficiencies at lower costs and with lower system risk of environmental harm.…”

The Impact on Global Warming of the Substitution of Refrigerant Fluids in Vapour Compression Plants: An Experimental Study

“…The former depends on the GWP of refrigerant fluids and on the fraction of refrigerant charge which is released into the atmosphere during operation and maintenance, or is not recovered when the system is scrapped [16,17]. The indirect contribution is energyrelated.…”

An experimental study of the lower flammability limit of LPG/halocarbon mixtures using the tubular burner apparatus

“…In September 1987, twenty-six countries (joined by 106 others in 1994) signed the Montreal Protocol, an international treaty to limit and subsequently phase out the production of all significant ozone depleting substances, including CFCs and Halons. The search to find ozone-safe chemical replacements to fill the void created by the implementation of the Protocol has also been complimented by the need to identify compounds that have minimal influence on global warming [4]. Many refrigerant alternatives have been proposed to date, ranging from more environmentally sound hydrochlorofluorocarbons (HCFCs) and other halogenated species, through to 'natural' refrigerants such as ammonia and hydrocarbons [5].…”