Effects of Pulsating Flow on the Performance of a Plate Heat Exchanger

맥동유동이 판형 열교환기 성능에 미치는 영향

The heat transfer enhancement by pulsating flow in a plate heat exchanger has been experimentally investigated in this study. The effect of the pulsating flow, such as pulsating frequency and flow rate, on the heat transfer as well as pressure drop in a plate heat exchanger has been studied in detail. Reynolds number in cold side of a plate heat exchanger is varied $100{\sim}530$ while that of hot side is fixed at 620. The pulsating frequency is considered in the range of $5{\sim}30$ Hz. The results of the pulsating flow are also compared with those of steady flow. It is found that the average heat transfer rate as well as pressure drop is increased as flow rate is increased for both steady flow and pulsating flow cases. When pulsating flow is applied to the plate heat exchanger, heat transfer could be substantially increased in particular ranges of pulsating frequency or Strouhal number; $St=0.36{\sim}0.60$ and pressure drop is also increased, compared with those of steady flow.