Comparison of bundle effect during flow boiling of distilled water over plain and plasma coated tube bundles

Abstract

The present article discusses about experimental investigation of improvement in row wise flow boiling heat transfer coefficients by using plasma coated 5 �3 tube bundle in comparison to plain tube bundles. The details of the flow boiling experimental setup and procedure are discussed. The variation of the row wise average heat transfer coefficients are presented and explained with respect to the operating parameters such as heat flux, mass flux and pitch to diameter ratio. The results are also compared with the row wise heat transfer coefficients for plain tube bundle. It is observed that the row wise heat transfer coefficient increases along the height for a given value of heat flux, mass flux and pitch to diameter ratio. The row wise heat transfer coefficient increases with heat flux but the rate of increase decreases at higher heat flux values. The row wise heat transfer coefficients does not vary significantly with mass flux up to a certain value and then decreases with it. The row wise variation of enhancement factor suggest to use mixed tube bundles for best results with lower cost. � 2018 International Heat Transfer Conference. All rights reserved.