Numerical-based non-dimensional analysis of critical flow of R-12, R-22, and R-134a through horizontal capillary tubes

Javidmand, Puya; Hoffmann, Klaus A.

doi:10.1016/j.ijrefrig.2015.06.003

Cited by 11 publications

(1 citation statement)

References 25 publications

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“…Still, it is inversely proportional to the cooling capacity. These findings agree with the investigation conducted by Javidmand and Hoffmann [12], Khunte and Mishra [13]. The effect temperature of the condenser At compared the results with the research of Jadhav and Agrawal [14], Li and Hrnjak [15], we noted that the temperature of the condenser is one of the most significant parameters that should be taken into account in studying the performance of the refrigeration cycle.…”

Section: Effect Length Of the Capillary Tubesupporting

confidence: 90%

Capillary Tube Length and Heat Transfer Dynamics in Air Conditioners: A Comparative Analysis of R-12 and Its Alternatives

Mohammed Ali,

Resen,

Ibrahim

2023

IJHT

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Refrigerant R12, or Freon 12, has been a predominant choice in various refrigeration and air conditioning applications due to its versatility across a broad spectrum of operating conditions. However, R12, a chlorofluorocarbon (CFC) with the chemical formula CCl2F2, poses a significant threat to the ozone layer, contributing to the greenhouse effect. Consequently, the phasing out of R12 is imperative. This study explores viable alternatives to R12, focusing on the impact of external temperature and other parameters on capillary tube length. A detailed comparison between refrigerant R-134a and R-12 is conducted using Engineering Equation Solver (EES) software at Q=366.5 W, d= 1.2 mm, Tconf =45℃ and tsurr=35℃. The software utilizes refrigerant thermodynamic and transport properties, including dynamic viscosity, density, thermal conductivity, and specific enthalpy, in the analysis. The research is aimed at understanding the flow dynamics in a capillary tube based on a model that aligns with the requirements of contemporary refrigerator design. Parameters such as operating conditions and tube diameter are scrutinized, with an emphasis on the direct relationship between them. The study also investigates the performance variability of the two refrigerants under identical conditions. A key finding is the superior quality of R-134a over R-12 in the two-phase region, coupled with the observation that the capillary tube length for R-134a is approximately 20% shorter than that for R-12. These results underscore the intricate relationship between refrigerant type, capillary tube dimensions, and overall system efficiency, thereby informing the design and optimization of next-generation refrigeration systems.

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Section: Effect Length Of the Capillary Tubesupporting

confidence: 90%