Heat transfer and pressure drop in a double pipe exchanger equipped with novel perforated magnetic turbulator (PMT): An experimental study

Abstract

The utilization of a magnetic turbulator presents a novel method for enhancing heat transfer in heat exchangers. This research introduces the use of both simple and perforated magnetic turbulators for the first time, aiming to optimize the thermal enhancement factor. The perforated magnetic turbulator is a composite of a magnet and a perforated oscillator. By inducing an alternating magnetic field around the tube, the magnet and, thus, the oscillator are forced to oscillate and as a result act as a flow disruptor. The oscillator is designed with holes in four varying diameters 1, 2, 3, and 4 mm and five distinct pitches 4, 6, 12, 18, and 24 mm to examine the impact on pressure drop and heat transfer. Also, to ascertain the optimal case, the thermal performance factor has been used. Tests have been carried out in the hot fluid flow range from 0.23 to 1.38 l/min. According to the results, the highest amount of heat transfer has been observed in the presence of a simple magnetic turbulator. The heat transfer and friction factor ratio in the presence of best case were 1.67 to 5.7 and 1.04 to 1.34 times higher than those of the plain tube, respectively. Meanwhile, the maximum value of the thermal performance coefficient (5.35) was observed in the presence of a perforated turbulator with a hole diameter of 2 mm and a pitch of 6 mm.