Vol.29 No.3(2) [2007]

Experimental Study on Local Heat Transfer Characteristics of Refrigerant R410A Condensing in a Multi-Port Extruded Tube

Xuesong WU, Shigeru KOYAMA and Ken KUWAHARA


In the present study, the local heat transfer characteristics are investigated experimentally for the condensation of a refrigerant R410A in a multi-port tube made of aluminum, which has 12 channels of 681.0 mm in length; 1.12 mm in hydraulic diameter. The tube-wall heat fluxes are measured in each subsection of 75mm in effective cooling length; the wall temperatures are also measured at 8 positions of each side of test-tube. The refrigerant pressure drops in 8 subsections are calculated with the measured pressures at inlet and outlet of the tube. The experiments are carried out with a mass velocity of G=100~300 kg/(m2s) and a constant inlet pressure of around 2.50 MPa. The experimental data of pressure drop are compared with the correlation of Koyama et al. correlation (2002), and local heat transfer coefficients are also compared with some correlations.