Abstract
Recently food transportation by the frozen cargo vehicles has been increasing. By opening and closing of the door in the case of carrying-in, taking-out or delivery, the super saturation moisture within high temperature and high relative humidity open air generates mist inside of the frozen space. This phenomenon influences the performance of heat exchangers. In this study, the mechanism of the mist deposition was investigated numerically. A concept of finless tube heat exchanger, which is composed of flat tubes, is proposed for achieving high performance under refrigeration frosting conditions. Several geometrical parameters based on the specifications of the trial product, such as spanwise tube pitch and longitudinal tube interval, were changed. Furthermore the trajectory of the particles was obtained and compared with the two cases, i.e. the case where no frost exists on the heat transfer surface and the case where frosts exist on it. The result showed the heat transfer characteristic of the heat exchanger and the tendency of mist deposition.
