单相自然循环回路的强化对流传热特性

doi:10.16085/j.issn.1000-6613.2019-1267

摘要/Abstract

摘要：

通过实验对比分析了带有单相自然循环回路元件的铜板与光滑铜板相隔冷热空气逆流换热的换热效果。结果表明，相同泵耗功情况下，加装单相自然循环回路元件的换热板的换热量是光滑铜板的1.1~1.3倍。在此基础上，本文通过数值模拟进一步对比分析了加装单相自然循环回路元件与相同形状、尺寸的铜翅片换热效果，针对影响自然循环回路传热性能的主要因素，如循环回路高度、横向与轴向倾斜角度、冷热源温差等，进行了数值模拟研究。结果表明：只有当温差超过等效温差点后，自然循环回路元件的换热效果才强于相同形状和尺寸的铜翅片；随着几何尺寸减少以及倾斜角度的增加，自然循环元件与铜翅片的等效温差点随之升高。

关键词: 单相自然循环回路, 强化传热, 数值模拟, 换热性能, 强化传热比

Abstract:

The heat transfer performance for a copper plate installed with single-phase natural circulation loop (SPNCL) was experimentally and numerically studied. Firstly, the heat transfer experiments between hot and cold air steams flow counter-currently in a rectangular channel separated by a copper plate installed with SPNCLs and a smooth copper plate were conducted, respectively. The results showed that, at the same power consumption, the heat transfer rate of the copper plate with SPNCLs is about 1.1—1.3 times as large as that of the smooth copper plate. In addition, the numerical simulations were performed for a comparison between the heat transfer rates of the SPNCL and the copper fin with the same shape and size. The effects of size, inclination angle and temperature difference between hot and cold air on the heat transfer rate were investigated in detail. The results showed that the heat transfer rate of the SPNCL can only be larger than that of the copper fin while the temperature difference is over an equivalent temperature difference. With the decrease of size and the increase of the inclination angle, the equivalent temperature difference between the SPNCL and the copper fin increases.

Key words: single-phase natural circulation loop, enhanced heat transfer, numerical simulation, heat transfer capability, enhanced heat transfer ratio

中图分类号:

曾龙,雷海燕,戴传山. 单相自然循环回路的强化对流传热特性[J]. 化工进展, 2020, 39(4): 1259-1266.

Long ZENG,Haiyan LEI,Chuanshan DAI. Heat transfer performance of a convection-enhanced heat transfer element——single-phase natural circulation loop[J]. Chemical Industry and Engineering Progress, 2020, 39(4): 1259-1266.

图/表 15

图1 实验装置示意图

图2 自然循环回路在平板上的示意图

表1 实验操作工况

热风机功率/W	热风入口温度/K	m·s^-1 V_h,p/	m·s^-1 V_h,1/	冷风入口温度/K	冷风变频器频率/Hz	m·s^-1 V_c,p/	m·s^-1 V_c,l/
180	343	2	1.8	299～301	5	1.4	1.1
	352				8	2.3	2.0
	363				15	4.0	3.5
	373				20	5.2	4.6

图3 不同泵耗功和热空气进口温度下光滑平板与带有自然循环回路的换热量

图4 带有自然循环回路板与光滑平板的强化传热比

图5 单个自然循环回路的换热模型示意图

图6 网格无关性验证

图7 自然循环回路剖面和横截面网格划分图

图8 自然循环回路与铜翅片换热性能的对比

图9 自然循环回路和铜翅片与周围流场的温度分布

图10 不同尺寸的自然循环回路与铜翅片换热性能的对比（图中点为数值解，线条为解析解）

图11 自然循环回路换热性能与铜翅片的对比图

图12 自然循环回路的两种倾斜示意图

图13 自然循环回路在XOY平面倾斜的换热量

图14 自然循环回路在XOY平面倾斜-90°、0°、90°时的速度分布以及流向

参考文献 13

1	王杰, 王茜. 热管科学及吸液芯研究进展回顾与展望[J]. 化工进展, 2015, 34(4): 891-902.
	WANG J, WANG Q. Development and expectation of heat-pipe technology and wick research[J]. Chemical Industry and Engineering Progress, 2015, 34(4): 891-902.
2	ZERROUKI A, BOUMEDIEN A, BOUHADEF K. The natural circulation solar water heater model with linear temperature distribution[J]. Renewable Energy, 2002, 26(4): 549-559.
3	QU J, WU H Y, CHENG P, et al. Recent advances in MEMS-based micro heat pipes[J]. International Journal of Heat and Mass Transfer, 2017, 110: 294-313.
4	YUN G, SU G H, WANG J Q, et al. Two-phase instability analysis in natural circulation loops of China advanced research reactor[J]. Annals of Nuclear Energy, 2005, 32(4): 379-397.
5	张文超, 肖雯. 水平换热通道自然循环流动特性分析[J]. 热能动力工程, 2017, 32(9): 26-32, 121.
	ZHANG W C, XIAO W. Flow characteristics of the natural circulation in a horizontal heat exchanger[J]. Journal of Engineering for Thermal Energy & Power, 2017, 32(9): 26-32, 121.
6	INAMPUDI S T, MARTHI B, SAHOO S. Entropy generation in water-based natural circulation loop[J]. Journal of Heat Transfer, 2018, 140(9): 092501.
7	CHENG H J, LEI H Y, DAI C S. Thermo-hydraulic characteristics and second-law analysis of a single-phase natural circulation loop with end heat exchangers[J]. International Journal of Thermal Sciences, 2018, 129: 375-384.
8	VIJAYAN P K, SHARMA M, SAHA D. Steady state and stability characteristics of single-phase natural circulation in a rectangular loop with different heater and cooler orientations[J]. Experimental Thermal and Fluid Science, 2007, 31(8): 925-945.
9	田春平, 阎昌琪, 王建军, 等. 倾斜对窄矩形通道内流动阻力特性影响[J]. 化工学报, 2016, 67(9): 3633-3639.
	TIAN C P, YAN C Q, WANG J J, et al. Effect of inclination on flow resistance characteristic in narrow rectangular channel[J]. CIESC Journal, 2016, 67(9): 3633-3639.
10	SADHU S, RAMGOPAL M, BHATTACHARYYA S. Experimental studies on an air-cooled natural circulation loop based on supercritical carbon dioxide-part A: steady state operation[J]. Applied Thermal Engineering, 2018, 133: 809-818.
11	MA H T, YIN L H, SHEN X P, et al. Experimental study on heat pipe assisted heat exchanger used for industrial waste heat recovery[J]. Applied Energy, 2016, 169:177-186.
12	TAO W Q, GUO Z Y, WANG B X. Field synergy principle for enhancing convective heat transfer-its extension and numerical verifications[J]. International Journal of Heat and Mass Transfer, 2002, 45(18): 3849-3856.
13	KRISHNANI M, BASU D N. Computational stability appraisal of rectangular natural circulation loop: effect of loop inclination[J]. Annals of Nuclear Energy, 2017, 107: 17-30.

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