Experimental study on the performance of one-directional and bi-directional flow conditions across in-line tube banks heat exchanger

Abstract

The one-directional flow condition and the bi-directional flow condition are two flow conditions that can be found in many energy systems depending on the nature of the flow and the working mechanism of the system. This paper reports the differences in heat transfer performance for an in-line tube banks heat exchanger that is placed in the one-directional and the bi-directional flow conditions. The experiments involve the use of a blower as a flow inducer for one-directional flow while a loudspeaker with a constant frequency of 14.2 Hz is used as a flow inducer for bi-directional flow condition. A quarter wavelength resonator with 4 mm wall thickness and a length of 6600 mm was used in the investigation. The results of velocity and temperature were recorded using a hotwire anemometer and a type-K thermocouple, respectively. Results show that the behaviour of velocity and temperature in one-directional and the bi-directional flow conditions over an in-line heated tube banks are different with a maximum difference of 52 % for velocity and 79 % for temperature.