Experimental study on direct contact condensation heat transfer in horizontal pipes

Abstract

Direct contact condensation is important to the safety analysis for nuclear power plants. Experimental studies have been performed to study the condensation heat transfer in stratified flow in a horizontal pipe. The experimental facility is made by stainless steel pipe with a length of 2100 mm and a diameter of 70 mm. The local temperatures of water layer are measured to find the local condensation rates and the local condensation heat transfer coefficients. The interfacial motion is an important parameter to the heat transfer coefficients. There are two shapes in the interfacial motion. One is a smooth interface at the inclination angle 0°, the other is a rough interface at the inclination angle 3°. The Nusselt numbers are correlated in terms of the steam Reynolds number, the water Reynolds number and the water Prandtl number for the case of inclination angles 0° and 3°, respectively. The effects of the inlet water temperature, the flow direction (countercurrent or cocurrent), and the inclination angle on the heat transfer coefficients are investigated. The effects of the flow direction and the inlet water temperature are smaller than those of the inclination angle. The measured heat transfer coefficients are 1 - 10 kW/㎡K which is smaller than those of other``s.