A study on direct contact heat transfer with phase change

Abstract

Direct Contact Heat Transfer With Phase Change between a dispersed and continuous liquid phase has recently attained importance in heat recovery systems associated with sea water desalination power generation etc The obvious advantages of this process are high newlineheat transfer coefficients smaller flow rates of the transfer fluid easy separation of fluids eliminating 1 metallic heat transfer surfaces which are prone to corrosion newlineefficient utilization of low temperature driving forces etc In practice the dispersed phase operates as a transfer fluid in a closed cycle evaporating and cooling the continuous phase medium at one temperature newlinelevel and condensing in the surrounding medium at a lower temperature level In the present study Direct Contact Heat Transfer involving the condensation of a bubble in an immiscible continuous phase liquid has been newlinestudied using Cine photography This study focusses attention on the dynamics and heat transfer mechanism of a collapsing two phase bubble Following a critical review of the work done the dissertation is divided into two main parts theoretical and experimental newlineThe theoretical portion starts with analysis newlineof two phase bubble dynamics in Ist less viscous continuous phase medium and high viscous continuous phase medium Correspondingly two different expressions for newlinepredicting the velocity of a two phase bubble have been derived The predicted values have been shown to be in good agreement with the experimental data