Study on Direct Condensation Heat Transfer of Steam on to Subcooled Water

Abstract

The application of a steam injector to nuclear rectors as a water supply pump and a low pressure injection pump has been investigated. The characteristics of the steam injector over wide range and its performance limit are examined in this studied. In the present paper, the disruption of a water jet of 5 mm diameter injected coaxially into a 20 mm diameter pipe of 100 mm long was studied. The sub-cooling and the velocity of the water jet tested were varied from 20 to 80℃ and from 4.2 to 17 m/s, respectively. The vapor flow rate was also varied from 8 to 50 kg/s. When the vapor flow rate was low or the water sub-cooling was low, the water jet maintained a round shape. However, the vapor flow rate became large and the water sub-cooling became high, the water jet became unstable and disrupted.