Thermal and hydraulic performance of a graphite block heat exchanger

In the present study, 3-D numerical simulations on heat and fluid flow characteristics of double-row multi-louvered fins heat exchanger are carried out. The heat transfer improvement and the corresponding pressure drop amounts were investigated depending on louver angles in the range of 20° ≤θ≤ 30°, louver pitches of Lp = 2,7mm, 3,5mm and 3,8mm and frontal velocities of Uin between 1.22 m/s and 3 m/s. The results are reported in terms of Colburn j-factor, Fanning friction factor f and area goodness factor j/f based on louver angle, louver pitch and Reynolds number. To understand local behavior of flow around louvered fins and heat exchanger tubes, flow visualization results of velocity vectors and stream-lines with temperature counters are presented. It is investigated that increasing louver angle enhances convective heat transfer while hydraulic performance decreases due to increased pressure drop. The flow noticeably behaves louver directed for all louver angles The flow can easily travel between different fins. This case study has been done to design and manufacture an industrial louver fin heat exchanger.

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Effect of the Moments of Probability Density Function for Non-uniform Air Flow Distribution on the Hydraulic Performance of a Fin-tube Heat Exchanger

Journal of Applied Sciences ◽

10.3923/jas.2011.1952.1958 ◽

2011 ◽

Vol 11 (11) ◽

pp. 1952-1958 ◽

Cited By ~ 1

Author(s):

Wai Meng Chin ◽

Vijay R. Raghavan

Keyword(s):

Heat Exchanger ◽

Probability Density Function ◽

Probability Density ◽

Density Function ◽

Air Flow ◽

Flow Distribution ◽

Hydraulic Performance ◽

Tube Heat Exchanger ◽

Fin Tube

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Research on the Thermal Hydraulic Performance and Entropy Generation Characteristics of Finned Tube Heat Exchanger with Streamline Tube

Energies ◽

10.3390/en13205408 ◽

2020 ◽

Vol 13 (20) ◽

pp. 5408

Author(s):

Zuoqin Qian ◽

Qiang Wang ◽

Song Lv

Keyword(s):

Heat Exchanger ◽

Entropy Generation ◽

Thermal Performance ◽

Flow Characteristics ◽

Hydraulic Performance ◽

Finned Tube ◽

Tube Heat Exchanger ◽

Finned Tube Heat Exchanger ◽

Overall Performance ◽

Present Simulation

Thermal hydraulic performance of the fin-and-tube heat exchanger is presented in this paper. The purpose of this investigation was to investigate the heat transfer mechanism and flow characteristics in the finned tube heat exchanger with streamline tube. The streamline tube in this paper had the streamline cross section which was composed of a semicircle and a half diamond. Three-dimensional numerical simulation was presented and validated by the experiment and the other numerical simulation from public articles. The present simulation had good agreement with the experimental results. The difference of the j factor and f factor between the experimental results and present simulation results by k-ε-enhance model was less than 7.6%. The geometrical parameters were considered as every single variable to investigate the thermal hydraulic performance. The results showed that smaller transversal and larger tube pitch provided greater compactness and better thermal performance. Moreover, a larger angle was not only beneficial to enhance the thermal performance, but also helpful to improve the overall performance. Secondly, the effects of angle on the heat transfer performance and fluid flow characteristics were investigated as the perimeter kept constant. It was shown that the overall performance of the streamline tube was better than the circular tube. Lastly, the entropy generation including frictional entropy generation and the thermal entropy generation were analyzed. It can be concluded that by using the streamline tube, the wake region can be obviously reduced, and thermal performance can be improved.

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