Abstract
An experimental study was conducted on gas-liquid flow distributions in a multi-pass channel with horizontal headers and upward-flow branches. Branches of the channel were heated to simulate a real operating condition of the evaporator. The refrigerant flow was visualized under the heated condition and it was compared with the adiabatic flow. Moreover, temperature distributions of branches were measured to estimate liquid distributions to branches, and they were compared with gas-liquid distribution ratios measured in an isothermal air-water flow. The refrigerant flow characteristics under the heated condition agreed qualitatively with those observed under the adiabatic condition, and the temperature distributions of branch surfaces were consistent with the water distributions. These results mean that gas-liquid distributions measured in the isothermal air-water flow can well reproduce the refrigerant flow distributions in an evaporator under operation.