3808 (RP-676) -- Shell-Side Condensation Heat Transfer of R-134a -- Part 3: Comparison with R-12 PDF

Shell-side condensation heat transfer coefficient data are compared for refrigerants R134a and R12 on tube bundles constructed from two finned-tube geometries and two enhanced-tube geometries. The tube bundles tested are five rows wide by five rows deep and have a staggered tube arrangement with a horizontal pitch of 22.2mm (0.875 in.) and a vertical pitch of 19.1mm (0.75 in.). The data were obtained at a refrigerant saturation temperature of 35 deg C (95 deg F) over a bundle heat flux range of 18,000 to 40,000 W/m² (5,700 to 12,700 Btu/[h×ft²] ). Average condensing heat transfer coefficients for the bundle as well as the middle tube of each row were calculated. The data show that R134a performs better than R12 on all four tube geometries. The data also show that for a given tube bundle, the row-to-row behaviour of both refrigerants is similar.

KEYWORDS: shell and tube condensers, condensation, heat transfer coefficient, refrigerants, R134a, R12, finned tubes, performance, heat flow, saturation temperature, experiment, testing, comparing