Analytical hierarchy process assessment of some refrigerants as alternatives for R-22 for vapor compression refrigeration systems

• Main Authors: Haboc, Paolo V., Dy, Bryce Jeremy T., Jara, Joshua Matthew T., Mendoza, Jethro C.
• Format: text
• Language: English
• Published: Animo Repository 2023
• Subjects: Refrigerants; Chemical Engineering; Engineering
• Online Access: https://animorepository.dlsu.edu.ph/etdb_chemeng/32; https://animorepository.dlsu.edu.ph/context/etdb_chemeng/article/1030/viewcontent/Analytical_Hierarchy_Process_Assessment_of_Some_Refrigerants_as_A_copy.pdf
• Institution: De La Salle University

Hydrochlorofluorocarbon refrigerants such as R-22 are commonly used in vapor compression refrigeration systems (VCRS) and are currently being phased out as it has ozone-depleting potential (ODP) and high global warming potential (GWP). Natural refrigerants are being explored as potential alternatives for R-22 in VCRS. In this study, R-290 and its refrigerant blends with other selected natural refrigerants such as R-290/R-1270, R-290/R-170, R-290/R-717 are assessed for the modelled VCRS. The alternatives are simulated in the modelled VCRS using Aspen Plus®, and the results are then utilized for the selection process. The selection of the optimal working fluid is then evaluated through the selected criteria, which are: coefficient of performance (COP), GWP, ODP, safety criteria, and costs. The criteria are ranked based on importance, through the insight of various experts on refrigeration cycles. The selection process is aided by the utilization of Analytic Hierarchy Process (AHP) in Google Sheets®. It was found that the most important criterion is COP with a criteria weight of 7, while the least important criteria are GWP and ODP with a criteria weight of 4.2. From the results of this study, it is found that the blend of 95% R-290 and 5% R-717 is the best option for the specific system to replace R-22, with a score of 0.9614. It was found that R-290 and blends of R-290 are suitable potential alternatives for R22. Binary interactions of blends were also examined through T-xy diagrams. It was observed that (1) R-290/R-1270 blends follow near azeotropic trends consistently on any concentration, (2) R-290/R-717 blends follow an azeotropic trend for most of the concentrations except at 320 kPa where it follows a zeotropic trend at higher concentrations, and (3) R-290/R-170 blends follow a consistent zeotropic trend.