Title: Heat Transfer Characteristics of Carbon Dioxide in a Inclined Helical Coil Type Heat Exchanger with Inner Diameter Tube of 4.55 mm
Abstract: The heat transfer coefficient and pressure drop during gas cooling process of (R-744) in inclined helical coil copper tubes were investigated experimentally. The main components of the refrigerant loop are a receiver, a variable-speed pump, a mass flow meter, a pre-heater and a inclined helical coil type gas cooler (test section). The test section consists of a smooth copper tube, which is specified as the inner diameter of 4.55 mm. The refrigerant mass fluxes were varied from 200 to and the inlet pressures of gas cooler were done 7.5 to 10.0 (MPa). The heat transfer coefficients of in the inclined helical coil tubes increase with the increase of mass flux and gas cooling pressure of . The pressure drop of in the gas cooler shows relatively good coincidence with those predicted by Ito's correlation developed for single-phase in a helical coil tube. The local heat transfer coefficient of is well coincident with the correlation by Pitla et al. However, at the region near pseudo-critical temperature, the experiments indicate higher values than the Pitla et al. correlation.
Publication Year: 2007
Publication Date: 2007-01-01
Language: en
Type: article
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