Characteristics of flow and heat transfer of shell-and-tube heat exchangers with overlapped helical baffles
The characteristics of flow and heat transfer of shell-and-tube heat exchangers with overlapped helical baffles (STHXsHB) were illustrated through a theoretical analysis and numerical simulation. The ideal helical flow model was constructed to demonstrate parts of the flow characteristics of the STHXsHB, providing theoretical evidence of short-circuit and back flows in a triangular zone. The numerical simulation was adopted to describe the characteristics of helical, leakage, and bypass streams. In a fully developed section, the distribution of velocity and wall heat transfer coefficient has a similar trend, which presents the effect of leakage and bypass streams. The short-circuit flow accelerates the axial velocity of the flow through the triangular zone. Moreover, the back flow enhances the local heat transfer and causes the ascent of flow resistance. This study shows the detailed features of helical flow in STHXsHB, which can inspire a reasonable optimization on the shell-side structure.
Keywordsheat exchanger overlapped helical baffle triangular zone helical flow
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- Cao X, Du W J, Ji S H, Cheng L (2012). Influence of overlap size on shell-side performance of heat exchangers with helical baffles. Proceedings of the CSEE, 32(8): 78–84 (in Chinese)Google Scholar
- Du W J, Wang H F, Cao X, Cheng L (2013). Heat transfer and fluid flow on shell-and-side of heat exchangers with novel sextant sector helical baffles. CIESC Journal, 64(9): 3123–3129 (in Chinese)Google Scholar
- Ji S H (2011). Mechanism analysis and performance study of flow and heat transfer in shell-side of shell-and-tube heat exchanger with helical baffles. Dissertation for the Doctoral Degree. Jinan: Shandong University (in Chinese)Google Scholar
- Lutcha J, Nemcansky J (1990). Performance improvement of tubular heat exchangers by helical baffles. Chemical Engineering Research & Design, 68(3): 263–270Google Scholar
- Master B I, Chunangad K S (2003). Venkateswaran pushpanathan, fouling mitigation using helixchanger heat exchangers. In: Proceedings of 2003 ECI Conference on Heat Exchanger Fouling and Cleaning: Fundamentals and Applications. 43Google Scholar
- Pletcher L S, Andrews M J (1994). Technical/market assessment of heat exchanger technology for users of natural gas. GRI Report GRI-94/0248Google Scholar
- Tao W Q (2001). Numerical Heat Transfer. Xi’an: Xi’an Jiaotong University Press (in Chinese)Google Scholar
- Wang L (2001). The experimental study of heat transfer and pressure drop for shell-and-tube heat exchangers with helical bafffles. Dissertation for the Doctoral Degree. Xi’an: Xi’an Jiaotong University (in Chinese)Google Scholar
- Wang L, Luo L Q, Wang Q W, Zeng M, Tao W Q (2001). Effect of inserting block plants on pressure drop and heat transfer in shell-sndtube heat exchangers with helical baffles. Journal of Engineering Thermophysics, 22(s): 173–177Google Scholar