Experimental investigation of heat transfer performance coefficient in tube bundle of shell and tube heat exchanger in two-phase flow

Abstract

This paper presents the results of studies in two phase gasliquid flow around tube bundle in the model of shell tube heat exchanger. Experimental investigations of heat transfer coefficient on the tubes surface were performed with the aid of electrochemical technique. Chilton-Colburn analogy between heat and mass transfer was used. Twelve nickel cathodes were mounted on the outside surface of one of the tubes. Measurement of limiting currents in the cathodic reduction of ferricyanide ions on nickel electrodes in aqueous solution of equimolar quantities of K3Fe(CN)6 and K4Fe(CN)6 in the presence of NaOH basic solution were applied to determine the mass transfer coefficient. Controlled diffusion from ions at the electrode was observed and limiting current plateau was measured. Measurements were performed with data acquisition equipment controlled by software created for this experiment. Mass transfer coefficient was calculated on the basis of the limiting current measurements. Results of mass transfer experiments (mass transfer coefficient) were recalculated to heat transfer coefficient. During the experiments, simultaneously conducted was the the investigation of two-phase flow structures around tubes with the use of digital particle image velocimetry. Average velocity fields around tubes were created with the use of a number of flow images and compared with the results of heat transfer coefficient calculations.

Local void fraction and heat transfer characteristics around tubes in two-phase flows across horizontal in-line and staggered tube bundles

“…Burnside et al (2001) investigated the heat-transfer coefficient along the flow direction and showed that the coefficient decreased marginally as the bundle row increases. Karas et al (2014) investigated the heat-transfer coefficient around a tube with the aid of an electrochemical technique that enabled them to obtain the local heat transfer around the tube. However, the relation between the local void fraction and the heat transfer around the tube was not fully investigated.…”

Effect of bubble motion on local heat transfer around a tube across horizontal in-line and staggered tube bundles in bubbly and intermittent flows

“…Therefore, it is expected that the improvement in the heat transfer coefficient due to the liquid agitation is higher in the staggered array than in the in-line array in bubbly flow. Karas et al (2014) performed experimental studies to measure the heat-transfer coefficient and velocity distributions around a tube in in-line and staggered bundles at p/d = 1.33. They showed that the heat transfer coefficients had the highest values at the frontal part of the tubes or at a place where the liquid velocity was the highest in most cases.…”

Archives of Thermodynamics

“…Jae et al [23] studied the use of this model in the industry predicting the new wall treatments and compared it with other turbulence models. Experimental investigation can be carried out by using other methods such as digital particle image velocimetry, where small quantities of non-dissolving reflecting substance are mixed with the fluid under study and imaging is carried out over intense laser beams [24].…”