Effect of corrugation pitch on thermo-hydraulic performance of nanofluids in corrugated tubes of heat exchanger system based on exergy efficiency. (15th April 2019)

• Record Type: Journal Article
• Authors: Wang, Guiqing; Qi, Cong; Liu, Maoni; Li, Chunyang; Yan, Yuying; Liang, Lin
• Is Part Of: Energy conversion and management. Volume 186(2019)
• Page Start: 51
• Page End: 65
• Publication Date: 2019-04-15
• Subjects: Nanofluids -- Forced convection -- Corrugated tube -- Exergy efficiency; Direct energy conversion -- Periodicals; Energy storage -- Periodicals; Energy transfer -- Periodicals; Énergie -- Conversion directe -- Périodiques; Direct energy conversion; Periodicals; 621.3105
• DOI: 10.1016/j.enconman.2019.02.046
• Languages: English
• ISSNs: 0196-8904

Abstract

Graphical abstract: Comprehensive performance indexes at different Reynolds numbers. Highlights: Effect of corrugation pitch on heat transfer and flow performance is studied. Thermo-hydraulic performance is analyzed by thermal and exergy efficiency. The exergy efficiency of smooth tube is better than that of corrugated tubes. Abstract: In this article, water and TiO2 -H2 O nanofluids are used as heat exchange mediums. The heat transfer and resistance coefficient of corrugated tubes with different corrugation pitches are studied by experimental method. The economy of experimental system is evaluated from the aspects of quantity and quality of energy by thermal and exergy efficiencies respectively. The heat transfer performance of nanofluids in the smooth tube can be enhanced by 2.64–16.9% compared with water under the same working conditions, while the corrugated tubes can improve the heat transfer performance by 4.8–66.3%. When the mass fraction of the nanofluid is 0.5%, the corrugated tubes with different corrugation pitches can increase the heat transfer by 36.3% ( P = 6 mm), 40.3% ( P = 4 mm) and 44.5% ( P = 2 mm) respectively. For thermal efficiency, the results prove that when the Reynolds number is larger than 6000, the comprehensive evaluation indexes of corrugated tubes are much larger than that of smooth tube, and the maximum can reach 1.5637. For exergy efficiency, the research results show that the exergy efficiency of the smooth tube is better than that of the corrugated tubes.