Alternative refrigerant mixtures to Isobutane (R-600a): energy efficiency enhancement and flammability reduction
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Show full item recordcomunitat-uji-handle:10234/9
comunitat-uji-handle2:10234/29747
comunitat-uji-handle3:10234/162759
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TESISMetadata
Title
Alternative refrigerant mixtures to Isobutane (R-600a): energy efficiency enhancement and flammability reductionAuthor (s)
Director
Llopis, Rodrigo; Sánchez García-Vacas, DanielDoctoral Studies
Programa de Doctorat en Tecnologies Industrials i MaterialsResponsible entity
Universitat Jaume I. Escola de DoctoratDate of defense
2024-06-25Description
Compendi d'articles, Doctorat internacional
Publisher
Universitat Jaume ISubject
Keywords
Pages
241 p.Abstract
This doctoral thesis explores alternative refrigerant mixtures to isobutane (R-600a) for vapor compression refrigeration systems, aiming to improve energy efficiency and reduce flammability. Isobutane, widely used in ... [+]
This doctoral thesis explores alternative refrigerant mixtures to isobutane (R-600a) for vapor compression refrigeration systems, aiming to improve energy efficiency and reduce flammability. Isobutane, widely used in Europe for domestic and low-capacity commercial refrigeration due to its low global warming potential (GWP) and good energy properties, is limited by its high flammability, restricting the maximum refrigerant charge and cooling capacity. This research identifies potential refrigerant blends that balance energy efficiency, volumetric capacity, low GWP, and flammability. A comprehensive thermodynamic analysis of 120 ternary blends of 10 refrigerants reveals promising mixtures such as R-1270/R-600, R-152a/R-600, R-1234yf/R-600, R-1234ze(E)/R-600, and R-290/R-600, which show significant increases in COP compared to R-600a. A new method created to theoretically predict the flammability class of new blends highlights the challenges in significantly reducing flammability by mixing hydrocarbons with less flammable refrigerants. Experimental tests on domestic and commercial refrigeration units demonstrate energy consumption savings with blends like R-1234yf/R-600a (7.5/92.5)%, R-1234ze(E)/R-600 (10.5/89.5)%, and R-290/R-600 (11/89)% in domestic units, and R-1234ze(E)/R-600 (8/92)% and R-152a/R-600 (8/92)% in commercial units. Optimal compositions for R-152a/R-600 and R-290/R-600 mixtures, tested on a specially constructed bench, show COP increases of 7.3% and 10.3%, respectively. The thesis concludes that certain binary blends can improve energy efficiency and maintain system compatibility but they cannot simultaneously achieve reduced flammability, increased efficiency, and low GWP. [-]
Rights
ADVERTIMENT. Tots els drets reservats. L'accés als continguts d'aquesta tesi doctoral i la seva utilització ha de respectar els drets de la persona autora. Pot ser utilitzada per a consulta o estudi personal, així com en activitats o materials d'investigació i docència en els termes establerts a l'art. 32 del Text Refós de la Llei de Propietat Intel·lectual (RDL 1/1996). Per altres utilitzacions es requereix l'autorització prèvia i expressa de la persona autora. En qualsevol cas, en la utilització dels seus continguts caldrà indicar de forma clara el nom i cognoms de la persona autora i el títol de la tesi doctoral. No s'autoritza la seva reproducció o altres formes d'explotació efectuades amb finalitats de lucre ni la seva comunicació pública des d'un lloc aliè al servei TDX. Tampoc s'autoritza la presentació del seu contingut en una finestra o marc aliè a TDX (framing). Aquesta reserva de drets afecta tant als continguts de la tesi com als seus resums i índexs.
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