Heat Transfer Enhancement of Partially Serrated Twisted Finned Tube Bank

Abstract

Due to the large thermal resistance on the airside of the air-cooled heat exchangers, it is necessary to improve heat transfer performance and reduce flow resistance by improving the fin structure. In this paper, partially serrated finned tube bank was proposed and numerically investigated. The experimental system of finned tube bank was built to verify the correctness of the numerical simulation. The finned tube bank is twisted and serrated on the windward side to enhance heat transfer. Moreover, the non-grooved sector region on the leeward side reduces the flow resistance and improves the temperature uniformity of the fins. The effects of fin twisting of the windward side and non-grooving angle of the leeward side were explored. Nusselt number and friction factor decrease as the leeward non-grooving sector region increases. The correlations of Nusselt number and friction factor were derived based on the simulation results of partially serrated twisted finned tube banks with 120° non-grooving region on the leeward side. Nusselt number, friction factor and comprehensive heat transfer coefficient of partially serrated twisted finned tube bank are 13.3%, 13.0% and 10.5% higher than that of annular finned tube bank with Reynolds number from 6200 to 20,600, respectively.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by China Petroleum and Chemical Corporation Technology Development Project (319013-7).

Notes on contributors

Hongyu Wei

Hongyu Wei is a master student of State Key Laboratory of Multiphase Flow in Power Engineering, Xi’an Jiaotong University, Xi’an, China. Her main research field is heat exchanger performance and energy efficiency improvement.

Tao Cong

Tao Cong works in Qingdao Haier Washing Machine Co., Ltd. He received his master’s degree in Power Engineering from Xi’an Jiaotong University in 2019. His main research interest is heat pump system and energy efficiency improvement.

Chen Jiang

Chen Jiang works in Shanghai Lanbin Petrochemical Equipment Co., Ltd. He received his Ph.D. degree in engineering thermo-physics from State Key Laboratory of Multiphase Flow in Power Engineering, Xi’an Jiaotong University in 2021. His main research interest is heat exchanger performance and energy efficiency improvement.

Wenxue Zhou

Wenxue Zhou is the secretary general of the Heat Exchanger Sub-committee of the National Technical Committee on the Standardization of Boilers and Pressure Vessels. His major research fields are heat exchanger standardization, performance test and energy efficiency evaluation.

Bofeng Bai

Bofeng Bai is a distinguished professor at Xi’an Jiaotong University, China. His research interests are fundamentals of multiphase flow and heat transfer, multiphase flow in propulsion systems, supercritical fluids, petroleum engineering, and enhancement of heat transfer. He is associate editor of both Measurement and Journal of Mechanical Engineering Science -Proc. IMechE, Part C.