Energy assessment and environmental impact analysis of an R134a/R744 cascade refrigeration plant upgraded with the low-GWP refrigerants R152a, R1234ze(E), propane (R290) and propylene (R1270)

Abstract

The European limitations associated with the use of fluorinated refrigerants have affected one of the most extended solutions used in commercial refrigeration in warm countries. Traditional cascade systems with R404A or R134a, in the high-temperature cycle, and R744 (CO 2 ), in the low side, will be prohibited from 2022 onwards unless the refrigerants used have a GWP 100 lower than 150. Since practically all the available refrigerants with low-GWP 100 are flammable, a simple but effective modification can be adopted upgrading the current direct expansion system to an indirect one. Accordingly, the aim of this work is to determine the energy and environmental impact of converting an R134a/CO 2 direct expansion cascade to an indirect one using the low-GWP 100 refrigerants R152a, R1234ze(E), R290 and R1270. The experimental analysis is performed at three different heat rejection temperatures (from 23.3 to 43.6 ºC), maintaining the cooling service product at temperatures of 2ºC and -20ºC on average.

Development of Environmentally - Friendly and Energy Efficient Refrigerant for Medium Temperature Refrigeration Systems

“…2. Examples of energy savings in refrigeration systems [7] Refrigerant trends in Thailand have shown improvements in increasing energy efficiency and decreasing global-warming potential (GWP), as shown in Figure 3 [8,9], which is related to the hydrofluorocarbon (HFC) phase-down schedule, as shown in Figure 4 [10]. First-and secondgeneration refrigerants were composed of natural refrigerants and hydrocarbons (HCs), both of which do not impact the environment, have low GWP, and zero ozone-depletion potential (ODP) [11][12][13].…”

Thermodynamic performance study on a novel absorption‐ compression cascade refrigeration activated by an internal combustion engine

“…Gholamian et al 31 Studied an NH 3 /CO 2 cascade refrigeration system and carried out modeling and comprehensive evaluation. Sanchez et al 32 investigated the energy consumption analysis and environmental impact in an R134a/R744 cascade refrigeration system. It was concluded that the utilization of R744 in the low‐temperature stage had a better performance compared to other refrigerants in the cascade systems.…”

Investigation and Analysis of Green Refrigerant Zero ODP as an Alternative Refrigerant Lower Cost and GWP

“…Refrigerant trends in Thailand have shown improvements in increasing energy efficiency and decreasing global-warming potential (GWP), as shown in Figure 3 [8,9], which is related to the hydrofluorocarbon (HFC) phase-down schedule, as shown in Figure 4 [10]. First-and second-generation refrigerants were composed of natural refrigerants and hydrocarbons (HCs), both of which do not impact the environment, have low GWP, and zero ozonedepletion potential (ODP) [11][12][13].…”