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Convective boiling of R-134a and R-123 on an enhanced tube bundle with standard pitch, RP-1316.

Author(s) : GORGY E., ECKELS S.

Type of article: Article

Summary

The current article presents the experimental investigation of the heat transfer performance of highly enhanced surfaced tube bundles. The two bundles studied are high pressure and low pressure TBII tubes for R134a and R123, respectively. The tube bundle is a staggered triangular arrangement with a tube pitch of (P/D 1.167). Twenty enhanced tubes were used in the bundle; the tube outer diameter and length are 19.05 mm (3/4 in.) and 1 m (39.36 in.), respectively. Three input variables were studied: heat flux 5–60 kW/m2 1585-19020 BTU/hr.ft2), mass flux 15–55 kg/m2.s (3–11 lb/s.ft2), and quality (10–70%). The test saturation temperature was 4.44°C (40 °F) for R134a and 14.44°C (58 °F) for R123. The local heat transfer performance of the bundle is reported. A local method employing the enthalpy based heat transfer technique was implemented in the data reduction. Both tube bundles showed a strong dependency on heat flux as expected. The R134a bundle showed a performance lower than that of pool boiling. The R123 bundle showed a secondary dependency on quality. The quality effect becomes pronounced at high qualities and high average bundle heat load. In the latter case, enhanced tubes performance drops quickly and reaches that of a smooth tube.

Details

  • Original title: Convective boiling of R-134a and R-123 on an enhanced tube bundle with standard pitch, RP-1316.
  • Record ID : 30008803
  • Languages: English
  • Source: HVAC&R Research - vol. 19 - n. 2
  • Publication date: 2013/02
  • DOI: http://dx.doi.org/10.1080/10789669.2012.754308

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