Theoretical comparison of low GWP alternatives for different refrigeration configurations taking R404A as baseline

Abstract

Six refrigerants are evaluated as low GWP replacements for R404A using different configurations, including two-stage system architectures. These refrigerants are selected according to similar characteristics to R404A, and they are the mid-term alternatives R407A and R407F, and the long-term alternatives: L40 and DR-7 (with very low GWP and low flammability), N40 and DR-33 (with low GWP and no flammability). In order to have a complete comparison range, various operating conditions are considered, covering low and medium evaporator temperatures and two levels of condensation temperatures. Configurations selected are presented and the equations used to simulate the expected performance are shown. From a given cooling capacity, volumetric flow rate and COP are compared, taking R404A as baseline. The most efficient alternatives are the low-flammable refrigerants, L40 and DR-7, and when no flammability is acceptable, N40 and DR-33 are also very good options.

Evaluation of R448A and R450A as low-GWP alternatives for R404A and R134a using a micro-fin tube evaporator model

“…The evaporating pressure is defined considering glide effects on heat exchangers, Eq. (1) is applied to correct R450A and R448A evaporating pressure [15,22].…”

“…As happens for R450A, this HFO/HFC mixture also presents good performance. Mota-Babiloni et al [22] studied theoretically six R404A alternatives in four vapour compression configurations, obtaining high efficiency simulating with R448A. Yana Motta [23], using a 2.2 kW semi-hermetic condensing unit with evaporator for walk-in freezer/cooler, show that R448A matches the capacity of R404A with 6% higher efficiency.…”

Performance evaluation of an ejector subcooled vapor-compression refrigeration cycle

“…High-GWP refrigerant R404A (GWP = 3260) as medium and low temperature refrigerant is widely used in the CVRC based commercial refrigeration. It needs to be gradually replaced by low-GWP refrigerants, such as R290 [28,29]. Therefore, in this study, the refrigerants R404A and possible alternative R290 used in small low-temperature cabinet freezers are selected as examples to analyze the performance of ESVRC cycle [30].…”

A New Mixture Refrigerant for Space Heating Air Source Heat Pump: Theoretical Modelling and Performance Analysis

“…Ln et al [27] found that the SEER and SCOP of R32 and mixing refrigerant R446A were higher than R410A by 8% and 1% in a residential heat pump system. A comparison of R404A with six low-GWP mixing refrigerants including mid-term alternatives R407A and R407F and long-term alternatives L40, DR-7, N40 and DR-33 was conducted by Mota-Babiloni et al [28] in terms of cooling capacity, volumetric flow rate and COP, and conclusions were given that the most efficient alternatives were the low-flammable refrigerants L40 and DR-7 considering two-stage and diverse operating conditions. Devecioglu [29] evaluated seasonal efficiency of four new low-GWP mixing refrigerants including R446A, R447A, R452B and R454B whose GWP values were lower than 750 and concluded that R452B has the most suitable SCOP among the alternative refrigerants.…”