Combined convective heat and pollutant removals in enclosures with different vented slots

doi:10.11949/0438-1157.20191091

Abstract

Abstract:

A numerical investigation of displacement ventilation on a heated and polluted strip within a partially open enclosure, having various locations of airflow inlet and outlet, is considered. The effects of different governing parameters on the fluid flow, heat and mass transfer were analyzed systematically. Results illustrated that the different arrangements of airflow inlet and outlet exhibit the dual effects on heat and mass transports and the radiuses of heat and mass dissipation within the enclosure. Both heat and mass transfer rates present larger values for the locations of inlet and outlet placed at the vertical sidewalls while they presents smaller radiuses of heat and mass dissipations for inlet and outlet placed at the two vertical and the top sidewalls, respectively. Results could be beneficial for heat and pollutant removals from the electronic boxes or building enclosures.

Key words: numerical simulation, laminar flow, transport processes, displacement ventilation, locations of inlet and outlet, slot ventilated enclosure

摘要：

通过数值模拟的手段研究不同进出口布置方式对置换通风模式下混合对流开口腔内热质输运过程的影响，并且利用流函数、热函数和质函数深入研究与揭示开口腔内热与气态污染物的输运过程与机理，系统分析了不同控制参数对开口腔内的气体流动结构和热质输运能力的影响。结果表明不同的进出口布置方式在开口腔内热和污染物的输运及其室内扩散范围上展现了相反的双重效果：进出口布置在两侧的方式具有更大的热与污染物输运能力；进口在两侧底部，出口位于顶部的布置方式在开口腔内具有更小的热与污染物扩散半径。研究结果对室内热与污染物排放和控制以及电子器件冷却有一定的借鉴意义。

关键词: 数值模拟, 层流, 传递过程, 置换通风, 进出口布置, 开口通风腔室

CLC Number:

TU 13

Lei WANG, Fuyun ZHAO, Yang CAI, Weiwei WANG, Yunhe WANG, Guobiao YANG. Combined convective heat and pollutant removals in enclosures with different vented slots[J]. CIESC Journal, 2020, 71(S1): 142-148.

王磊, 赵福云, 蔡阳, 汪维伟, 王云鹤, 杨国彪. 置换通风模式下多元对流室内热与污染物输运[J]. 化工学报, 2020, 71(S1): 142-148.

Figures/Tables 8

Fig.1 Displacement ventilation model A

Fig.2 Displacement ventilation model B

Fig.3 Contours of streamlines, isotherms, isoconcentrations, heatlines and masslines for DV model A (from top to bottom)

Fig.4 Contours of streamlines, isotherms, isoconcentrations, heatlines and masslines for DV model B (from top to bottom)

Fig.5 Effects of Archimedes number on Nusselt number for different displacement ventilation models

Fig.6 Effects of Archimedes number on Sherwood number for different displacement ventilation models

Fig.7 Variations of maximum temperature level with changing Archimedes number for different displacement ventilation models

Fig.8 Variations of maximum pollutant concentration level with changing Archimedes number for different displacement ventilation models

References 30

1	Papanicolaou E, Jaluria Y. Mixed convection form an isolated heat source in a rectangular enclosure [J]. Numer. Heat Tr. A - Appl., 1990, 18(4): 427-461.
2	Tsu T H, Hsu P T, How S P. Mixed convection in a partially divided rectangular enclosure [J]. Numer. Heat Tr. A - Appl., 1997, 31(6): 655-683.
3	Raji A, Hasnaoui M. Mixed convection heat transfer in a rectangular cavity ventilated and heated from the side [J]. Numer. Heat Tr. A-Appl., 1998, 33(5): 533-548.
4	Manca O, Nardini S, Khanafer K. Experimental investigation of mixed convection in a channel with an open cavity [J]. Exp. Heat Transfer., 2006, 19(1): 53-68.
5	Lee H, Awbi H B. Effect of internal partitioning on indoor air quality of rooms with mixing ventilation — basic study [J]. Build. Environ., 2004, 39(2): 127-141.
6	Bilgenm E, Muftuoglu A. Cooling strategy by mixed convection of a discrete heated at its optimum position in a square cavity with ventilation ports [J]. Int. Commun. Heat Mass Transfer, 2008, 35(5): 545-550.
7	Stiriba Y, Grau F X, Ferre J A, et al. A numerical study of three-dimensional laminar mixed convection past an open cavity [J]. Int. J. Heat Mass Transfer, 2010, 53(21/22): 4797-4808.
8	Liu D, Zhao F Y, Wang H Q. Passive heat and moisture removal from a natural vented enclosure with a massive wall [J]. Energy, 2011, 36(5): 2867-2882.
9	Papanicolaou E, Jaluria Y. Mixed convection from a localized heat source in a cavity with conducting walls: a numerical study [J]. Numer. Heat Tr. A - Appl., 1993, 23(4): 463-484.
10	Singh S, Sharif M A R. Mixed convection cooling of a rectangular cavity with inlet and exit openings on differentially heated side walls [J]. Numer. Heat Tr. A - Appl., 2003, 44(3): 233-253.
11	Tmartnhad I, Alami M E, Najian M, et al. Numerical investigation on mixed convection flow in a trapezoidal cavity heated from below [J]. Energ. Convers. Manage., 2008, 49(11): 3205-3210.
12	Arce J, Xaman J, Alvarez G. Numerical study of mixed convection and conduction in a 2-D square ventilated cavity with an inlet at the vertical glazing wall and outlet at the top surfaces [J]. Heat and Mass Transfer, 2011, 47(2): 223-236.
13	Rahman M M, Oztop H F, Mekhilef S, et al. Simulation of unsteady heat and mass transport with heatline and massline in a partially heated open cavity [J]. Appl. Math. Model, 2015, 39(5/6): 1597-1615.
14	Fontana E, Capeletto C A, Silva A, et al. Numerical analysis of mixed convection in partially open cavities heated from below [J]. Int. J. Heat Mass Transfer, 2015, 81(1): 829-845.
15	Yoo J S. Dual steady solutions in natural convection between horizontal concentric cylinders [J]. Int. J. Heat Fluid Fl., 1996, 17(6): 587-593.
16	Yang L, Xu P, Li Y. Nonlinear dynamic analysis of natural ventilation in a two-zone building: Part A — Theoretical analysis [J]. HVAC&R Research, 2006, 12(2): 231-255.
17	Alloui Z, Dufau L, Beji H, et al. Multiple steady states in a porous enclosure partially heated and fully salted from below [J]. Int. J. Therm. Sci., 2009, 48(3): 521-534.
18	Zhao F Y, Rank E, Liu D, et al. Dual steady transports of heat and moisture in a vent enclosure with all round states of ambient air [J]. Int. J. Heat Mass Transfer, 2012, 55(23/24): 6979-6993.
19	Zhao F Y, Liu D, Tang G F. Multiple steady fluid flows in a slot-ventilated enclosure [J]. Int. J. Heat Fluid Fl., 2008, 29(5): 1295-1308.
20	Liu D, Zhao F Y, Tang G F. Non-unique convection in a three-dimensional slot-vented cavity with opposed jets [J]. Int. J. Heat Mass Transfer, 2010, 53(5/6): 1044-1056.
21	Ren X H, Hu J T, Liu D, et al. Combined convective heat and airborne pollutant removals in a slot vented enclosure under different flow schemes: parametric investigations and non unique flow solutions [J]. Appl. Therm. Eng., 2016, 94(1): 159-169.
22	Zhang D D, Cai Y, Liu D, et al. Dual steady flow solutions of heat and pollutant removal from a slot ventilated welding enclosure containing a bottom heating source [J]. Int. J. Heat Mass Transfer, 2019, 132(1): 11-24.
23	Muftuoglu A, Bilgen E. Natural convection in an open square cavity with discrete heaters at their optimized positions [J]. Int. J. Therm. Sci., 2008, 47(4): 369-377.
24	Bilgen E, Oztop H. Natural convection heat transfer in partially open inclined square cavities [J]. Int. J. Heat Mass Transfer, 2005, 48(8): 1470-1479.
25	Zhang J H, Zhang D D, Liu D, et al. Free vent boundary conditions for thermal buoyancy driven laminar flows inside open building enclosures [J]. Build Environ., 2017, 111(1): 10-23.
26	Kimura S, Bejan A. The “heatline” visualization of convective heat transfer [J]. J. Heat Transfer, 1983, 105(4): 916-919.
27	Zhao F Y, Liu D, Tang G F. Application issues of the streamline, heatline, and massline for conjugate heat and mass transfer [J]. Int. J. Heat Mass Transfer, 2007, 50(1/2): 320-334.
28	Patankar S V. Numerical Heat Transfer and Fluid Flow [M]. New York: Hemisphere., 1980: 120-129.
29	Zhao F Y, Liu D, Tang G F. Conjugate heat transfer in sqaure enclosures [J]. Heat Mass Transfer, 2007, 43(9): 907-922.
30	Liu D, Zhao F Y, Tang G F. Conjugate heat transfer in an enclosure with a centered conducting body imposed sinusoidal temperature profiles on one side [J]. Numer. Heat Tr. A - Appl., 2008, 53(2): 204-223.

[1]	Zhanyu YE, He SHAN, Zhenyuan XU. Performance simulation of paper folding-like evaporator for solar evaporation systems [J]. CIESC Journal, 2023, 74(S1): 132-140.
[2]	Yifei ZHANG, Fangchen LIU, Shuangxing ZHANG, Wenjing DU. Performance analysis of printed circuit heat exchanger for supercritical carbon dioxide [J]. CIESC Journal, 2023, 74(S1): 183-190.
[3]	Zhiguo WANG, Meng XUE, Yushuang DONG, Tianzhen ZHANG, Xiaokai QIN, Qiang HAN. Numerical simulation and analysis of geothermal rock mass heat flow coupling based on fracture roughness characterization method [J]. CIESC Journal, 2023, 74(S1): 223-234.
[4]	Jiahao SONG, Wen WANG. Study on coupling operation characteristics of Stirling engine and high temperature heat pipe [J]. CIESC Journal, 2023, 74(S1): 287-294.
[5]	Siyu ZHANG, Yonggao YIN, Pengqi JIA, Wei YE. Study on seasonal thermal energy storage characteristics of double U-shaped buried pipe group [J]. CIESC Journal, 2023, 74(S1): 295-301.
[6]	Song HE, Qiaomai LIU, Guangshuo XIE, Simin WANG, Juan XIAO. Two-phase flow simulation and surrogate-assisted optimization of gas film drag reduction in high-concentration coal-water slurry pipeline [J]. CIESC Journal, 2023, 74(9): 3766-3774.
[7]	Chen HAN, Youmin SITU, Bin ZHU, Jianliang XU, Xiaolei GUO, Haifeng LIU. Study of reaction and flow characteristics in multi-nozzle pulverized coal gasifier with co-processing of wastewater [J]. CIESC Journal, 2023, 74(8): 3266-3278.
[8]	Lei XING, Chunyu MIAO, Minghu JIANG, Lixin ZHAO, Xinya LI. Optimal design and performance analysis of downhole micro gas-liquid hydrocyclone [J]. CIESC Journal, 2023, 74(8): 3394-3406.
[9]	Xiaosong CHENG, Yonggao YIN, Chunwen CHE. Performance comparison of different working pairs on a liquid desiccant dehumidification system with vacuum regeneration [J]. CIESC Journal, 2023, 74(8): 3494-3501.
[10]	Wenzhu LIU, Heming YUN, Baoxue WANG, Mingzhe HU, Chonglong ZHONG. Research on topology optimization of microchannel based on field synergy and entransy dissipation [J]. CIESC Journal, 2023, 74(8): 3329-3341.
[11]	Rui HONG, Baoqiang YUAN, Wenjing DU. Analysis on mechanism of heat transfer deterioration of supercritical carbon dioxide in vertical upward tube [J]. CIESC Journal, 2023, 74(8): 3309-3319.
[12]	Kexin HUANG, Tong LI, Anqi LI, Mei LIN. Mode decomposition of flow field in T-junction with rotating impeller [J]. CIESC Journal, 2023, 74(7): 2848-2857.
[13]	Fangzhe SHI, Yunhua GAN. Numerical simulation of start-up characteristics and heat transfer performance of ultra-thin heat pipe [J]. CIESC Journal, 2023, 74(7): 2814-2823.
[14]	Xingchi ZHU, Zhiyuan GUO, Zhiyong JI, Jing WANG, Panpan ZHANG, Jie LIU, Yingying ZHAO, Junsheng YUAN. Simulation and optimization of selective electrodialysis magnesium and lithium separation process [J]. CIESC Journal, 2023, 74(6): 2477-2485.
[15]	Juhui CHEN, Qian ZHANG, Lingfeng SHU, Dan LI, Xin XU, Xiaogang LIU, Chenxi ZHAO, Xifeng CAO. Study on flow characteristics of nanoparticles in a rotating fluidized bed based on DEM method [J]. CIESC Journal, 2023, 74(6): 2374-2381.