Article,
Flow characteristics of gas-liquid two-phase flow in plate heat exchanger: (Visualization and void fraction measurement by neutron radiography)
Experimental Thermal and Fluid Science, 28 (2-3): 223 - 230 (2004)<ce:title>The International Symposium on Compact Heat Exchangers</ce:title>.
DOI: 10.1016/S0894-1777(03)00043-8
Abstract
In order to clarify the gas-liquid two-phase flow characteristics in a plate heat exchanger, gas-liquid two-phase flows in simulated heat exchangers with a single channel placed in a vertical plane were visualized by a neutron radiography method. Air-water adiabatic two-phase flows and chlorofluorocarbon R141b boiling two-phase flows were visualized, and two-dimensional void fraction distributions were measured from visualized images via some image processing techniques. Moreover, total pressure loss of adiabatic air-water two-phase flows through the test section was measured, and the frictional pressure loss was calculated by using measured results of average void fraction. As a result, it was shown that the phase distributions in heat exchangers were strongly affected by the inlet configuration and the inlet conditions. When the incoming flow was a gas-liquid two-phase flow, liquid stagnation at the test section inlet caused unsymmetrical phase distribution. For high gas volumetric flux, both phases tended to flow straight separately. Moreover, it was shown that the average void fractions and the frictional pressure loss of adiabatic air-water two-phase flows in the ribbed channel could be correlated by the drift-flux model and the L-M method, respectively.
