ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Intensification of heat transfer in a liquid film evaporator

Pavol Timár Jr., Lenka Nemsilová, Pavel Timár, Ján Stopka, Ladislav Štibrányi, and Vladimír Báleš

Institute of Chemical and Environmental Engineering, Faculty of Chemical and Food Technology, Slovak University of Technology in Bratislava, Radlinského 9, 812 37, Bratislava, Slovakia

E-mail: pavel.timar@stuba.sk

Abstract: Influence of the heat exchanger shape on the heat transfer efficiency investigated. Heat transfer efficiency of two vertical pipe-in-pipe heat exchangers, one with a straight wall and the other with a twisted wall were compared. Both heat exchangers worked on the principle of liquid falling film. Electric transformer oil was used as the heated liquid and water vapor at atmospheric pressure was used as the heating agent. Oil was just heated, not evaporated during the experiments. Oil inlet and outlet temperature were measured at six different oil mass flows. Heat flux and heat flux density in the straight- and twisted-wall heat exchangers were compared. Mathematical model was built to verify the possibility of the oil outlet temperature prediction.

Keywords: falling film – heat transfer intensification – level-set method

Full paper is available at www.springerlink.com.

DOI: 10.2478/s11696-014-0627-6

Chemical Papers 68 (12) 1774–1778 (2014)