An experimental heat-transfer study for a heat-recovery unit made of corrugated tubes

Poredoš, Primož (author), Šuklje, Tomaž (author), Medved, Sašo (author), Arkar, Ciril (author)

This paper presents a study of the thermal characteristics of a concentric-tube heat exchanger that is a key element in local ventilation device. The inner tube of the concentric-tube heat exchanger has a sinusoidal, wavy surface in the longitudinal direction, which enables heat-transfer enhancement. The tube can be stretched to a certain extent and thus change the corrugation of the heat-transfer surface area. We designed an experiment in which we used the Wilson-plot method to separately determine the convective heat-transfer coefficient on the inside and outside of the inner tube of the concentric-tube heat exchanger with different corrugation ratios. Based on the measurements correlation equations were developed to calculate the convective heat-transfer coefficient for any corrugation ratio, which allows us to simplify the design of local ventilation devices. Performed studies showed that, compared to a smooth tube, the convective heat-transfer coefficient increased only in the case of corrugated tubes with a corrugation ratio of less than 1.648, but the heat transfer was more intense for all considered corrugated tubes by 65-90% due to the increased heat-transfer surface area. The highest heat-transfer rate was observed for the case of the maximum-stretched tube with a corrugation ratio of 1.401, which is advantageous also in terms of material consumption.

• Language: English
• Keywords: convective heat-transfer coefficient, corrugated tubes, Wilson-plot method, heat exchanger
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FS - Faculty of Mechanical Engineering
• Publication status: Published
• Publication version: Author Accepted Manuscript
• Year: 2013
• Number of pages: Str. 49-56
• Numbering: Vol. 53, iss. 1
• PID: 20.500.12556/RUL-125698
• UDC: 697:628.8
• ISSN on article: 1359-4311
• DOI: 10.1016/j.applthermaleng.2013.01.004
• COBISS.SI-ID: 12647963
• Publication date in RUL: 02.04.2021

Record is a part of a journal

• Title: Applied thermal engineering
• Shortened title: Appl. therm. eng.
• Publisher: Elsevier
• ISSN: 1359-4311
• COBISS.SI-ID: 1861910

Licences

• License: CC BY-NC-ND 4.0, Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International
• Link: http://creativecommons.org/licenses/by-nc-nd/4.0/
• Description: The most restrictive Creative Commons license. This only allows people to download and share the work for no commercial gain and for no other purposes.
• Licensing start date: 02.04.2021

Secondary language

• Language: Slovenian
• Keywords: koeficient toplotne prestopnosti, Wilsonova metoda, prenosnik toplote, orebrene cevi

Projects

• Funder: ARRS - Slovenian Research Agency
• Project number: P2-0223
• Name: Prenos toplote in snovi