Experimental investigation on straight and u-bend double tube heat exchanger with active and passive enhancement methods

Abstract

Authors in this work want to demonstrate the possibility to increase the heat transfer efficiency by using simple wire coil inserts to create turbulent flow in the boundary layer as well as air blowing into the annulus of the pipe. In the study, Wilson plot approach was applied in order to estimate heat transfer coefficients for all heat exchanger (HX) configurations. The study focuses on experimental values of heat transfer coefficient (HTC) and pressure drops. The primary objectives of the work are to: I. Provide an experimental comprehensive database for HTC and pressure drops; II. Analysis effect of different flow conditions e.g. water mass flow rate, the void fraction on heat transfer and hydraulic performance of tested elements. III. Compare influences of both passive and active methods at the efficiency of simple heat exchangers constructions; IV. Validation experimental results with selected experimental models from the open literature.

Archives of Thermodynamics

“…Andrzejczyk et al [17] investigated individual heat exchanger constructions with plain double tube, turbulized double tube , plain U-bend and U-bend with turbulator. Tests were made for the water-water system for a constant temperature of 9 • C and 50 • C. The heat exchangers were made from copper tubes with external diameter of 10 mm and 18 mm respectively and wall thickness of 1 mm.…”

Archives of Thermodynamics

“…Issues in experimental research and heat exchanger design are also frequently presented in scientific articles. An extensive experimental study for four different heat exchanger designs made of different materials was performed in [1]. As a result, the heat transfer efficiency was determined for the heat exchanger designs studied.…”