不同结构凹穴微通道内超临界氮气流动与传热特性

doi:10.16085/j.issn.1000-6613.2022-2246

摘要/Abstract

摘要：

为了实现微通道换热器表面结构的高效设计，本文将数值模拟和实验手段相结合，以超临界氮气（supercritical nitrogen，SCN₂）为流体工质，研究了不同凹穴形状（直微通道、圆形、矩形和梯形）和椭圆度对微通道流动与传热特性的影响，揭示了SCN₂高效低阻强化换热机理。结果表明，相比于直微通道，圆形凹穴微通道中轴线上SCN₂速度达到稳定值所需入口段距离更短，这是由于凹穴能够促使流体流动/热边界层一直处于破坏与重建的交替状态。圆形凹穴内流体旋涡形状与凹穴几何结构保持一致，其流阻特性和换热性能最优，梯形凹穴微通道次之，矩形凹穴微通道最差。微通道综合性能随着凹穴椭圆度增加呈先升高后降低变化趋势，当椭圆度为1时，其综合性能最优。研究结果对提高微通道换热器设计制造能力具有重要的意义。

关键词: 微通道, 超临界氮气, 凹穴, 结构, 流动与传热

Abstract:

In order to realize the efficient design of the surface structure of the micro-channel heat exchanger, the effects of cavity shapes (straight micro-channel, circular, rectangular and trapezoidal) and ovality on the flow and heat transfer performance of micro-channel were studied by means of numerical simulation and experiment, using supercritical nitrogen as the fluid medium, the mechanism of fluid efficient and low resistance heat transfer enhancement was revealed. The results showed that compared with the straight micro-channel, the entrance distance required for the SCN₂velocity on the axis of the circular cavity micro-channel to reach a stable value was shorter, which was due to the fact that the cavity can promote the fluid flow/thermal boundary layer to be in the alternate state of destruction and reconstruction all the time. The shape of the fluid vortex in the circular cavity was consistent with the cavity geometry, and its flow resistance and heat transfer performance were optimal, followed by trapezoidal cavity micro-channel and rectangular cavity micro-channel. With the increase of ovality, the overall performance of cavity micro-channel increased firstly and then decreased. When the ovality was 1, the overall performance was optimal. The research results in this paper are of great significance for improving the design and manufacturing capability of micro-channel heat exchangers.

Key words: micro-channel, supercritical nitrogen, cavity, structure, flow and heat transfer

中图分类号:

TE088

韩昌亮, 黄峄演, 徐建全. 不同结构凹穴微通道内超临界氮气流动与传热特性[J]. 化工进展, 2023, 42(11): 5592-5601.

HAN Changliang, HUANG Yiyan, XU Jianquan. Flow and heat transfer characteristics of supercritical nitrogen in micro-channel with different cavity structures[J]. Chemical Industry and Engineering Progress, 2023, 42(11): 5592-5601.

图/表 15

图1 物理模型示意图

表1 凹穴微通道几何参数

参数	数值
计算域总长（L）/mm	540
凹穴中心间距（L₁）/mm	78
每一侧凹穴个数（N）	6
入口截面高度（H）/mm	1
入口截面宽度（W）/mm	3
圆形凹穴半径（R）/mm	1.5
矩形凹穴宽度（W₁）/mm	3
矩形凹穴高度（W₂）/mm	3
梯形凹穴宽度（W₃）/mm	1.5
梯形凹穴高度（W₄）/mm	1.5

表2 边界条件设置

位置	边界类型	参数设置
微通道入口	质量流量入口边界	G_in=650~950kg/(m²·s)； T_in=113K
微通道出口	压力出口边界	P_out=7.5MPa
微通道左/右壁面	对称面边界	—
固体壁面与SCN₂交界面	无滑移边界	u=v=w=0
微通道上/下壁面	恒定热流密度边界	q=120kW/m²；δ=2mm

表3 不同网格系统下SCN2出口温度和出口速度

序号	网格数目	出口温度/K	出口速度/m·s^-1	最小单元尺寸/mm
1	2044992	196.05	4.19	0.2
2	2780601	189.57	3.52	0.17
3	3729528	177.78	3.05	0.15
4	4224407	177.62	3.02	0.14
5	5376328	177.51	3.00	0.13

图2 7.5MPa下SCN2热物性

图3 SCN2换热器测试实验系统示意图1—鼓风机；2—转子流量计；3—燃料罐；4—燃烧器；5—数据采集仪；6—水箱；7—PT100热电阻；8—压力变送器；9—高压调节阀；10—气体质量流量计；11—增压泵；12—自增压杜瓦罐

图4 管束通道内SCN2对流传热系数实验值与模拟值对比

图5 微通道中轴线上SCN2速度分布

图6 范宁摩擦系数对比图

图7 努塞尔数和出口SCN2温度对比图

图8 不同凹穴形状微通道中轴线上SCN2速度对比图

图9 不同形状凹穴微通道范宁摩擦系数对比图

图10 不同形状凹穴微通道努塞尔数对比图

图11 不同凹穴椭圆度微通道范宁摩擦系数对比图

图12 不同凹穴椭圆度微通道努塞尔数对比图

参考文献 29

1	袁旭东, 贾磊, 周到, 等. 微通道临界热通量的基础理论与提升技术研究进展[J]. 化工学报, 2021, 72(4): 1796-1814.
	YUAN Xudong, JIA Lei, ZHOU Dao, et al. Research progress on basic theory and improvement technology for critical heat flux of microchannel[J]. CIESC Journal, 2021, 72(4): 1796-1814.
2	DENG Daxiang, ZENG Long, SUN Wei. A review on flow boiling enhancement and fabrication of enhanced microchannels of microchannel heat sinks[J]. International Journal of Heat and Mass Transfer, 2021, 175: 121332.
3	陆威, 苗冉, 吴志根, 等. 非牛顿流体在波节套管换热器中流动与换热的实验研究[J]. 化工学报, 2022, 73(7): 2924-2932.
	LU Wei, MIAO Ran, WU Zhigen, et al. Experimental study on flow and heat transfer of non-Newtonian fluid in a corrugated double-tube heat exchanger[J]. CIESC Journal, 2022, 73(7): 2924-2932.
4	谷家扬, 魏世松, 景宝金, 等. 紧凑高效微通道换热器流动与换热特性研究进展[J]. 江苏科技大学学报(自然科学版), 2020, 34(6): 42-49.
	GU Jiayang, WEI Shisong, JING Baojin, et al. Progress in the research of flow and heat transfer characteristics of printed circuit heat exchangers[J]. Journal of Jiangsu University of Science and Technology (Natural Science Edition), 2020, 34(6): 42-49.
5	ZHOU Jinzhi, CAO Xiaoling, ZHANG Nan, et al. Micro-channel heat sink: A review[J]. Journal of Thermal Science, 2020, 29(6): 1431-1462.
6	雷丽, 李慧玲, 赵玉婷, 等. 凹穴型微通道液-液两相流动特性[J]. 高校化学工程学报, 2020, 34(6): 1360-1367.
	LEI Li, LI Huiling, ZHAO Yuting, et al. Characteristics of liquid-liquid two-phase flow in microchannels with reentrant cavities[J]. Journal of Chemical Engineering of Chinese Universities, 2020, 34(6): 1360-1367.
7	李艺凡, 王志鹏. 带有周期性扰流结构的微通道内流动与传热特性[J]. 化工进展, 2022, 41(6): 2893-2901.
	LI Yifan, WANG Zhipeng. Flow and heat transfer characteristics in microchannels with periodic fluid disturbance structures[J]. Chemical Industry and Engineering Progress, 2022, 41(6): 2893-2901.
8	ZHAO Zhongchao, ZHANG Yong, CHEN Xudong, et al. Experimental and numerical investigation of thermal-hydraulic performance of supercritical nitrogen in airfoil fin printed circuit heat exchanger[J]. Applied Thermal Engineering, 2020, 168: 114829.
9	CHENG He, YIN Liang, JU Yonglin, et al. Experimental investigation on heat transfer characteristics of supercritical nitrogen in a heated vertical tube[J]. International Journal of Thermal Sciences, 2020, 152: 106327.
10	韩昌亮, 辛镜青, 于广滨, 等. 微通道内超临界氮气三维热流场实验与数值模拟[J]. 化工学报, 2022, 73(2): 653-662.
	HAN Changliang, XIN Jingqing, YU Guangbin, et al. Experimental and numerical simulation on three-dimensional heat flow field of supercritical nitrogen in micro-channel[J]. CIESC Journal, 2022, 73(2): 653-662.
11	LASHKARBOLOKI Mostafa, VAEZIAN Ahmad, HEZAVE Ali Zeinolabedini, et al. Experimental investigation of the influence of supercritical carbon dioxide and supercritical nitrogen injection on tertiary live-oil recovery[J]. The Journal of Supercritical Fluids, 2016, 117: 260-269.
12	YU Qinghua, PENG Yuxiang, NEGOESCU Ciprian Constantin, et al. Study on convective heat transfer of supercritical nitrogen in a vertical tube for liquid air energy storage[J]. Energies, 2021, 14(22): 7773.
13	DONDAPATI Raja Sekhar. Role of Supercritical Nitrogen (SCN) on the hydraulic and thermal characteristics of futuristic High Temperature Superconducting (HTS) cables[J]. Cryogenics, 2020, 111: 103166.
14	CONG Tenglong, WANG Zhenhong, ZHANG Rui, et al. Thermal-hydraulic performance of a PCHE with sodium and sCO₂ as working fluids[J]. Annals of Nuclear Energy, 2021, 157: 108210.
15	KUROSE Kizuku, WATANABE Naoto, MIYATA Kazushi, et al. Numerical simulation of flow and cooling heat transfer of supercritical pressure refrigerants in chevron-type plate heat exchanger[J]. International Journal of Heat and Mass Transfer, 2021, 180: 121758.
16	白书诚, 吴俐俊, 田梦雨. 波纹板式换热器传热与流动特性分析[J]. 热能动力工程, 2022, 37(6): 114-121.
	BAI Shucheng, WU Lijun, TIAN Mengyu. Analysis of heat transfer and flow characteristics of corrugated plate heat exchanger[J]. Journal of Engineering for Thermal Energy and Power, 2022, 37(6): 114-121.
17	谢瑶, 李剑锐, 胡海涛. 印刷电路板式换热器内超临界甲烷流动换热特性模拟[J]. 化工学报, 2021, 72(S1): 203-209.
	XIE Yao, LI Jianrui, HU Haitao. Simulation of supercritical methane flow and heat transfer characteristics in printed circuit heat exchanger[J]. CIESC Journal, 2021, 72(S1): 203-209.
18	XU Minghai, LU Hui, GONG Liang, et al. Parametric numerical study of the flow and heat transfer in microchannel with dimples[J]. International Communications in Heat and Mass Transfer, 2016, 76: 348-357.
19	QU Weilin, MALA Gh Mohiuddin, LI Dongqing. Heat transfer for water flow in trapezoidal silicon microchannels[J]. International Journal of Heat and Mass Transfer, 2000, 43(21): 3925-3936.
20	CHAI Lei, XIA Guodong, WANG Huasheng. Laminar flow and heat transfer characteristics of interrupted microchannel heat sink with ribs in the transverse microchambers[J]. International Journal of Thermal Sciences, 2016, 110: 1-11.
21	孙文骏. 两种新型微通道散热器结构优化及传热特性的数值研究[D]. 桂林: 桂林理工大学, 2021.
	SUN Wenjun. Numerical study on structural optimization and heat transfer characteristic of two new microchannel heat sinks[D]. Guilin: Guilin university of technology, 2021.
22	吴秋瑜. 凹穴型微通道换热器结构设计与性能研究[D]. 广州: 华南理工大学, 2017.
	WU Qiuyu. Performance study and structure design of microchannel heat exchanger with fan-shaped cavities[D]. Guangzhou: South China University of Technology, 2017.
23	高博, 焦永刚, 田玉思, 等. 截面积尺寸对微通道换热器流动特性的影响机理[J]. 石家庄铁道大学学报 (自然科学版), 2021, 34(3): 81-86.
	GAO Bo, JIAO Yonggang, TIAN Yusi, et al. Influence mechanism of cross section size on flow characteristics of microchannel heat exchanger[J]. Journal of Shijiazhuang Tiedao University (Natural Science Edition), 2021, 34(3): 81-86.
24	陈涛, 王桂莲, 吴永进, 等. 交错内肋微通道的流动和传热特性研究[J]. 热能动力工程, 2022, 37(9): 128-135.
	CHEN Tao, WANG Guilian, WU Yongjin, et al. Study on flow and heat transfer characteristics of microchannels with staggered internal ribs[J]. Journal of Engineering for Thermal Energy and Power, 2022, 37(9): 128-135.
25	陈一航, 张引弟, 黄纪琛, 等. 双锥型凹穴微通道超临界CO₂流动传热特性研究[J]. 低温工程, 2022 (4): 6-13.
	CHEN Yihang, ZHANG Yindi, HUANG Jichen, et al. Study on heat transfer characteristics of supercritical CO₂ flow in double-cone-shaped cavity microchannels[J]. Cryogenics, 2022(4): 6-13.
26	LEMMON Eric W, MCLINDEN Mark O, HUBER Marcia L. NIST standard reference database 23: NIST thermodynamics and transport properties REFPROP, Version 7.0 [S]. 2002.
27	HAN Changliang, REN Jingjie, WANG Yanqing, et al. Experimental studies of shell-side fluid flow and heat transfer characteristics in a submerged combustion vaporizer[J]. International Journal of Heat and Mass Transfer, 2016, 101: 436-444.
28	HAN Changliang, REN Jingjie, WANG Yanqing, et al. Experimental investigation on fluid flow and heat transfer characteristics of a submerged combustion vaporizer[J]. Applied Thermal Engineering, 2017, 113: 529-536.
29	KLINE S J, MCCLINTOCK F A. Describing uncertainties in single-sample experiments[J]. Mechanical Engineering, 1953, 75: 3-8.

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