Date of Publication

2-2023

Document Type

Bachelor's Thesis

Degree Name

Bachelor of Science in Chemical Engineering

Subject Categories

Chemical Engineering | Engineering

College

Gokongwei College of Engineering

Department/Unit

Chemical Engineering

Thesis Advisor

Allan N. Soriano
John Frederick D. Tapia

Defense Panel Chair

Luis F. Razon

Defense Panel Member

Raymond Girard R. Tan
Gian Paolo O. Bernardo

Abstract/Summary

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.

Abstract Format

html

Language

English

Format

Electronic

Keywords

Refrigerants

Upload Full Text

wf_yes

Embargo Period

3-27-2024

Share

COinS