1. Performance investigation on the novel anti-leakage and easy-to-manufacture trisection helical baffle electric heaters.
- Author
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Gu, Huaduo, Chen, Yaping, Wu, Jiafeng, Fei, Fengfan, and Sundén, Bengt
- Subjects
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LASER beam cutting , *HEAT transfer coefficient , *HEATING , *HEAT exchangers , *HEAT transfer - Abstract
• A novel helical baffle with small inclined angle and folded structure is proposed. • The new helical baffles can be created by cheap 2D laser cutting and folding. • The leakage between two folded helical baffles can be greatly decreased. • The novel electric heaters have excellent flow and heat transfer performances. • Folded helical baffles are more excellent at large equivalent angles in this work. The difficult manufacturing of helical baffles hinders the widespread application of the enhancement technology and the shortcut leakage between adjacent baffles impairs the enhancement effects. To solve these two issues, the promising anti-leakage and easy-to-manufacture helical baffles with small inclined angle and folded structure are proposed, which can be produced by 2D laser cutting and simple mechanical folding. The influence of different helical baffle configurations, including three normal helical schemes, three axial separation helical schemes, three novel folded axial separation helical baffle schemes and a segmental scheme on the performance of electric heaters are numerically investigated. The equivalent angles of helical schemes adopted in this work are 15°, 20° and 25°, and the inclined angle of helical baffles under axial separation connection style is 10°. Compared with the corresponding axial separation scheme without folding, the leakage can be significantly decreased, the heat transfer coefficients h and the comprehensive indices h ⋅Δ p −1/3 of FH15(10)°, FH20(10)° and FH25(10)° are increased by 6.5%/2.3%, 12.2%/7.3% and 20.4%/13.0%, and the averaged tube wall temperatures T w are decreased by 12.5 K, 25.4 K and 54.7 K, respectively. This research can provide feasibility for the extended application of helical baffles in electric heaters or heat exchangers. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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