Open Access

ARTICLE

EXPERIMENTAL STUDY OF THE THERMAL PERFORMANCE OF CORRUGATED HELICALLY COILED TUBE-IN-TUBE HEAT EXCHANGER

by

Power Mechanics Techniques Engineering Department, Al-Musaib Technical College
Al-Furat Al-Awsat Technical University, Kufa, Iraq
* Corresponding author. Email: hussein83@atu.edu.iq

Frontiers in Heat and Mass Transfer 2023, 20, 1-7. https://doi.org/10.5098/hmt.20.17

Abstract

Transferring thermal energy efficiently necessitates utilizing a heat exchanger capable of producing the full thermal power of the energy supply at lowest possible cost and time. Therefore, in the present investigation, the impact of corrugated helical coil concentric tube-in-tube heat exchanger on the thermal performance is investigated experimentally. As a continuous in our issue of heat exchanger, the corrugated helical tube-in-tube is carried out and compared with smooth helical tube-in-tube for free convection heat transfer. The set-up of the experimental apparatus are designed and utilized to be appropriate for the cooling and heating systems of working fluid. The impacts of geometry and operating conditions on the thermal and hydraulic characteristics such as the thermal effectiveness, whole coefficient of heating-transfer, number of thermal unit, pressure drop, Number of Dean and Number of Nusselt are taken into consideration of this investigation. The steady state flow condition and the counter flow direction are assumed in this investigation. The experimental results demonstrated that the whole coefficient of heating-transfer, effectiveness, number of thermal units, and Number of Nusselt were improved significantly due to the adoption of the corrugated helical coil tube-in-tube heat exchanger. This is happened because of the impact of geometrical configuration of corrugated tube in comparison with that of smooth tube, which is affected on increasing of the coefficient of heating-transfer. The maximum enhancement magnitude of the whole coefficient of heating-transfer was 33% for water flow rate of 16 L/min. For the latter water flow rate, effectiveness found that the maximum enhancement was 35%. The high magnitudes of NTU and Number of Nusselt were 3.37 and 218.5, respectively at the corrugated coil tube-in-tube for 16 L/min of hot water flow rate. The pressure drop for the corrugated tube was higher than that of smooth tube due to the swirl flow of hot water inner tube.

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