Abstract
In this paper, a novel polymer bare-tube heat exchanger (BTHX) with an ogive tube shape and a sinusoidal wavy channel is proposed and investigated for the liquid-to-gas application. The thermal-hydraulic performance of the proposed polymer BTHX is calculated using a validated computational fluid dynamics (CFD) simulation model, and the performance is optimized by setting nine independent design variables. A selective-series CFD method with an approximation-assisted optimization technique is developed for the multi-objective optimization to reduce the computational time. As a result, the thermal-hydraulic performance of the optimized novel polymer BTHX shows 91.5% and 134.9% of that of the target aluminum louvered-fin micro-channel heat exchanger (MCHX), respectively. This is mainly due to the improved air-side heat transfer coefficient of the proposed polymer BTHX by 70.2% compared to the target aluminum MCHX. Compared to the recent teardrop-shaped polymer BTHX, the thermal-hydraulic performance of the proposed BTHX is significantly improved. Regarding the polymer thermal conductivity, it is found that the thermal performance degradation can be minimized with at least 8.0 W∙m−1∙K−1 of the thermal conductivity. The flow field of the proposed polymer BTHX is also discussed and shows that the unique structure of the sinusoidal wavy tube can reduce the air-side pressure drop and promote the mixing of the air flow, thereby improving the air-side convective heat transfer.
Original language | English |
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Article number | 120785 |
Journal | International Journal of Heat and Mass Transfer |
Volume | 166 |
DOIs | |
Publication status | Published - 2021 Feb |
Bibliographical note
Funding Information:This research was supported by the program of Korea Institute of Energy Technology Evaluation and Planning ( KETEP , No. 20198510010040 ), and by the program of the National Research Foundation of Korea . ( NRF-2020R1C1C1011195 ).
Publisher Copyright:
© 2020
Keywords
- Bare-tube heat exchanger
- Multi-objective optimization
- Polymer heat exchanger
- Selective-series CFD
- Sinusoidal wavy channel
ASJC Scopus subject areas
- Condensed Matter Physics
- Mechanical Engineering
- Fluid Flow and Transfer Processes