方形微通道内超临界CO2流动换热特性研究

doi:10.11949/0438-1157.20211466

摘要/Abstract

摘要：

采用SST k-ω湍流模型对加热条件下超临界CO₂在方形微通道内的流动换热特性进行了数值模拟。通过对比三种壁面平均传热系数、浮升力参数和二次流强度的沿程变化研究了管型、热通量、质量流量和倾斜角度对微通道内流动换热性能的影响。结果表明：水平方形微通道的整体换热性能优于相同水力直径的半圆形微通道。流体域典型截面的温度分布、速度分布和湍动能分布等信息可以很好地解释水平方向流动时上、下壁面传热差异的现象。减小热通量、增大质量流量或减小流体流动方向与重力方向之间的夹角，可提高方形微通道的整体换热水平。该模拟结果对以超临界CO₂为工质的微通道换热器的设计和优化具有一定的理论指导意义。

关键词: 超临界二氧化碳, 数值模拟, 传热, 浮升力效应, 二次流强度

Abstract:

The heat transfer characteristic of supercritical CO₂ in tubes is the key factor affecting the overall performance of heat exchangers. In recent years, square microchannels have shown broad application prospects in compact and efficient printed circuit heat exchangers. The SST k-ω turbulent model was used to simulate the heat transfer characteristics of supercritical CO₂ in square microchannels under uniform heating conditions. The effects of flow channel shape, heat flux, mass flow rate and inclination angle on heat transfer performance in microchannels were studied by comparing three average heat transfer coefficients, buoyancy parameter and secondary flow intensity. The results show that the overall heat transfer performance of horizontal square microchannels is better than that of semicircular microchannels with the same hydraulic diameter. The temperature distribution, velocity distribution and turbulent kinetic energy distribution of typical sections in the fluid domain can well explain the non-uniform heat transfer phenomenon in horizontal microchannels. The overall heat transfer level of square microchannels can be improved by decreasing the heat flux, increasing the mass flow rate or decreasing the angle between the flow direction and the gravity direction. The simulation results have certain theoretical significance for the design and optimization of microchannel heat exchangers using supercritical CO₂ as working medium.

Key words: supercritical CO₂, numerical simulation, heat transfer, buoyancy effect, second flow intensity

中图分类号:

TK 124

许婉婷, 许波, 王鑫, 陈振乾. 方形微通道内超临界CO₂流动换热特性研究[J]. 化工学报, 2022, 73(4): 1534-1545.

Wanting XU, Bo XU, Xin WANG, Zhenqian CHEN. Heat transfer characteristics of supercritical CO₂ in square microchannels[J]. CIESC Journal, 2022, 73(4): 1534-1545.

图/表 16

图1 CO2在压力为8.0 MPa时的热物性曲线

Fig.1 Thermal properties of CO2 at P = 8.0 MPa

图2 物理模型示意图

Fig.2 Schematic diagram of physical model

表1 不同模拟工况的边界条件设置

Table 1 Boundary conditions under different simulated conditions

入口温度T_in/K

热通量q /

(kW/m²)

质量流量G /

(kg/(m²·s))

0,30,60,90,-30,-60,-90

表2 不同尺寸网格下的流体温度和平均传热系数偏差

Table 2 Deviations of bulk temperature and average heat transfer coefficient under different grid sizes

序号	网格数量（径向）×横向	网格总数/万个	流体温度最大相对误差/%	平均传热系数最大相对误差/%
Grid1	(48×48)×500	115.2	0.10	3.69
Grid2	(48×48)×1000	230.4	0.03	3.11
Grid3	(48×48)×2000	460.8	0.01	2.29
Grid4	(54×54)×500	145.8	0.09	1.98
Grid5	(54×54)×1000	291.6	0.02	0.86
Grid6	(54×54)×2000	583.2	—	—

图3 模拟结果与传热关联式对比

Fig.3 Comparisons of simulated results with predicted data from heat transfer correlations

图4 方管和半圆管的壁面平均传热系数和流体温度（P=8.0 MPa, Tin=303.15 K,G=400 kg/(m2·s),q=60 kW/m2）

Fig.4 Heat transfer coefficient and local bulk temperature in square and semicircular tubes

图5 重力对壁面温度的影响(P=0.8 MPa, Tin=303.15 K, q=60 kW/m2, G=400 kg/(m2·s))

Fig.5 Effect of gravity on wall temperature

图6 热通量对传热系数的影响（P=8.0 MPa, Tin=303.15 K,G=400 kg/(m2·s)）

Fig.6 Effect of heat flux on heat transfer coefficient

图7 质量流量对传热系数的影响（P=8.0 MPa, Tin=303.15 K,q=60 kW/m2）

Fig.7 Effect of mass flow rate on heat transfer coefficient

图8 倾斜角度对传热系数的影响（P=8.0 MPa, Tin=303.15 K,q=60 kW/m2, G=400 kg/(m2·s)）

Fig.8 Effect of inclination angle on heat transfer coefficient

图9 特征截面处的典型参数分布

Fig.9 Distribution of typical parameters at characteristic cross-sections

图10 特征截面处的轴向速度和湍动能径向分布曲线

Fig.10 Radial distribution curves of axial velocity and turbulent kinetic energy at characteristic cross-sections

图11 沿程浮升力参数和二次流强度变化曲线（P=8.0 MPa, Tin=303.15 K,q=60 kW/m2,G=400 kg/(m2·s)）

Fig.11 Variation curves of buoyancy parameter and secondary flow intensity

图12 热通量对浮升力参数和二次流强度的影响（P=8.0 MPa, Tin=303.15 K,G=400 kg/(m2·s)）

Fig.12 Effect of heat flux on buoyancy parameter and secondary flow intensity

图13 质量流量对浮升力参数和二次流强度的影响（P=8.0 MPa, Tin=303.15 K,q=60 kW/m2）

Fig.13 Effect of mass flow rate on buoyancy parameter and secondary flow intensity

图14 倾斜角度对二次流强度和壁面温度的影响（P=8.0 MPa, Tin=303.15 K,q=60 kW/m2,G=400 kg/(m2·s)）

Fig.14 Effect of inclination angle on secondary flow intensity and wall temperature

参考文献 36

1	Wu P, Ma Y D, Gao C T, et al. A review of research and development of supercritical carbon dioxide Brayton cycle technology in nuclear engineering applications[J]. Nuclear Engineering and Design, 2020, 368: 110767.
2	Jiang P X, Zhang F Z, Xu R N. Thermodynamic analysis of a solar-enhanced geothermal hybrid power plant using CO₂ as working fluid[J]. Applied Thermal Engineering, 2017, 116: 463-472.
3	Ma Y T, Liu Z Y, Tian H. A review of transcritical carbon dioxide heat pump and refrigeration cycles[J]. Energy, 2013, 55: 156-172.
4	Ehsan M M, Guan Z Q, Klimenko A Y. A comprehensive review on heat transfer and pressure drop characteristics and correlations with supercritical CO₂ under heating and cooling applications[J]. Renewable and Sustainable Energy Reviews, 2018, 92: 658-675.
5	Gkountas A A, Stamatelos A M, Kalfas A I. Recuperators investigation for high temperature supercritical carbon dioxide power generation cycles[J]. Applied Thermal Engineering, 2017, 125: 1094-1102.
6	Zhao P H, Wan T, Jin Y X, et al. Direct numerical simulation analysis of heat transfer deterioration of supercritical fluids in a vertical tube at a high ratio of heat flux to mass flowrate[J]. Physics of Fluids, 2021, 33(5): 055114.
7	Zhu B G, Zhu X J, Xie J, et al. Heat transfer prediction of supercritical carbon dioxide in vertical tube based on artificial neural networks[J]. Journal of Thermal Science, 2021, 30(5): 1751-1767.
8	Zhang S J, Xu X X, Liu C, et al. Experimental investigation on the heat transfer characteristics of supercritical CO₂ at various mass flow rates in heated vertical-flow tube[J]. Applied Thermal Engineering, 2019, 157: 113687.
9	Yan C S, Xu J L, Zhu B G, et al. Numerical analysis on heat transfer characteristics of supercritical CO₂ in heated vertical up-flow tube[J]. Materials (Basel, Switzerland), 2020, 13(3): 723.
10	Liao S M, Zhao T S. Measurements of heat transfer coefficients from supercritical carbon dioxide flowing in horizontal mini/micro channels[J]. Journal of Heat Transfer, 2002, 124(3): 413-420.
11	Kim T H, Kwon J G, Kim M H, et al. Experimental investigation on validity of buoyancy parameters to heat transfer of CO₂ at supercritical pressures in a horizontal tube[J]. Experimental Thermal and Fluid Science, 2018, 92: 222-230.
12	Wang J Y, Guan Z Q, Gurgenci H, et al. Computational investigations of heat transfer to supercritical CO₂ in a large horizontal tube[J]. Energy Conversion and Management, 2018, 157: 536-548.
13	Kumar N, Basu D N. Computational appraisal of the thermalhydraulic characteristics of supercritical carbon dioxide in heated mini-channel for HVAC applications[J]. IOP Conference Series: Earth and Environmental Science, 2020, 463(1): 012048.
14	Xiang M R, Guo J F, Huai X L, et al. Thermal analysis of supercritical pressure CO₂ in horizontal tubes under cooling condition[J]. The Journal of Supercritical Fluids, 2017, 130: 389-398.
15	杨传勇, 徐进良, 王晓东, 等. 超临界参数CO₂在倾斜管内对流换热数值模拟[J]. 热力发电, 2013, 42(1): 26-35.
	Yang C Y, Xu J L, Wang X D, et al. Numerical simulation of convective heat transfer for supercritical CO₂ in inclined tubes[J]. Thermal Power Generation, 2013, 42(1): 26-35.
16	闫晨帅, 朱兵国, 尹少军, 等. 倾斜圆管内超临界压力CO₂流动换热数值分析[J]. 中国科学: 技术科学, 2020, 50(5): 571-581.
	Yan C S, Zhu B G, Yin S J, et al. Numerical analysis on flow and heat transfer characteristics of supercritical pressure CO₂ in inclined tube[J]. Scientia Sinica (Technologica), 2020, 50(5): 571-581.
17	Zhang L N, Liu M S, Dong Q W, et al. Numerical research of heat transfer of supercritical COR2R in channels[J]. Energy and Power Engineering, 2011, 3(2): 167-173.
18	Guo J F, Huai X L. Coordination analysis of cross-flow heat exchanger under high variations in thermodynamic properties[J]. International Journal of Heat and Mass Transfer, 2017, 113: 935-942.
19	Li H Z, Zhang Y F, Zhang L X, et al. PDF-based modeling on the turbulent convection heat transfer of supercritical CO₂ in the printed circuit heat exchangers for the supercritical CO₂ Brayton cycle[J]. International Journal of Heat and Mass Transfer, 2016, 98: 204-218.
20	Zhang Y D, Peng M J, Xia G L, et al. Numerical investigation on local heat transfer characteristics of S-CO₂ in horizontal semicircular microtube[J]. Applied Thermal Engineering, 2019, 154: 380-392.
21	Wen Z X, Lv Y G, Li Q, et al. Numerical study on heat transfer behavior of wavy channel supercritical CO₂ printed circuit heat exchangers with different amplitude and wavelength parameters[J]. International Journal of Heat and Mass Transfer, 2020, 147: 118922.
22	Li Y, Sun F, Xie G N, et al. Numerical investigation on flow and thermal performance of supercritical CO₂ in horizontal cylindrically concaved tubes[J]. Applied Thermal Engineering, 2019, 153: 655-668.
23	Zhang S J, Xu X X, Liu C, et al. The buoyancy force and flow acceleration effects of supercritical CO₂ on the turbulent heat transfer characteristics in heated vertical helically coiled tube[J]. International Journal of Heat and Mass Transfer, 2018, 125: 274-289.
24	Chen W, Yang Z N, Yang L, et al. Numerical investigation of heat transfer and flow characteristics of supercritical CO₂ in U-duct[J]. Applied Thermal Engineering, 2018, 144: 532-539.
25	Kim J K, Jeon H K, Lee J S. Wall temperature measurements with turbulent flow in heated vertical circular/non-circular channels of supercritical pressure carbon-dioxide[J]. International Journal of Heat and Mass Transfer, 2007, 50(23/24): 4908-4911.
26	Hasan M I, Rageb A A, Yaghoubi M, et al. Influence of channel geometry on the performance of a counter flow microchannel heat exchanger[J]. International Journal of Thermal Sciences, 2009, 48(8): 1607-1618.
27	Besarati S M, Yogi Goswami D, Stefanakos E K. Development of a solar receiver based on compact heat exchanger technology for supercritical carbon dioxide power cycles[J]. Journal of Solar Energy Engineering, 2015, 137(3): 031018.
28	Zhang H Y, Guo J F, Huai X L, et al. Thermodynamic performance analysis of supercritical pressure CO₂ in tubes[J]. International Journal of Thermal Sciences, 2019, 146: 106102.
29	Lei Y C, Chen Z Q. Numerical study on cooling heat transfer and pressure drop of supercritical CO₂ in wavy microchannels[J]. International Journal of Refrigeration, 2018, 90: 46-57.
30	Khalesi J, Sarunac N. Numerical analysis of flow and conjugate heat transfer for supercritical CO₂ and liquid sodium in square microchannels[J]. International Journal of Heat and Mass Transfer, 2019, 132: 1187-1199.
31	Yang Z N, Chen W, Chyu M K. Numerical study on the heat transfer enhancement of supercritical CO₂ in vertical ribbed tubes[J]. Applied Thermal Engineering, 2018, 145: 705-715.
32	Menter F R. Two-equation eddy-viscosity turbulence models for engineering applications[J]. AIAA Journal, 1994, 32(8): 1598-1605.
33	Liao S M, Zhao T S. An experimental investigation of convection heat transfer to supercritical carbon dioxide in miniature tubes[J]. International Journal of Heat and Mass Transfer, 2002, 45(25): 5025-5034.
34	Wang L, Pan Y C, Lee J D, et al. Experimental investigation in the local heat transfer of supercritical carbon dioxide in the uniformly heated horizontal miniature tubes[J]. International Journal of Heat and Mass Transfer, 2020, 159: 120136.
35	Yang C Y, Xu J L, Wang X D, et al. Mixed convective flow and heat transfer of supercritical CO₂ in circular tubes at various inclination angles[J]. International Journal of Heat and Mass Transfer, 2013, 64: 212-223.
36	Wang X C, Xiang M J, Huo H J, et al. Numerical study on nonuniform heat transfer of supercritical pressure carbon dioxide during cooling in horizontal circular tube[J]. Applied Thermal Engineering, 2018, 141: 775-787.

编辑推荐 0

Metrics

阅读次数

全文

967

HTML			PDF

最新录用	在线预览	正式出版	最新录用	在线预览	正式出版
3	0	14	14	0	936

来源	本网站	其他网站

次数	193	774
比例	20%	80%

摘要

458

最新录用	在线预览	正式出版

31	0	427

来源	本网站	其他网站

次数	314	144
比例	69%	31%

[1]	叶展羽, 山訸, 徐震原. 用于太阳能蒸发的折纸式蒸发器性能仿真[J]. 化工学报, 2023, 74(S1): 132-140.
[2]	张双星, 刘舫辰, 张义飞, 杜文静. R-134a脉动热管相变蓄放热实验研究[J]. 化工学报, 2023, 74(S1): 165-171.
[3]	张义飞, 刘舫辰, 张双星, 杜文静. 超临界二氧化碳用印刷电路板式换热器性能分析[J]. 化工学报, 2023, 74(S1): 183-190.
[4]	陈爱强, 代艳奇, 刘悦, 刘斌, 吴翰铭. 基板温度对HFE7100液滴蒸发过程的影响研究[J]. 化工学报, 2023, 74(S1): 191-197.
[5]	刘明栖, 吴延鹏. 导光管直径和长度对传热影响的模拟分析[J]. 化工学报, 2023, 74(S1): 206-212.
[6]	王志国, 薛孟, 董芋双, 张田震, 秦晓凯, 韩强. 基于裂隙粗糙性表征方法的地热岩体热流耦合数值模拟与分析[J]. 化工学报, 2023, 74(S1): 223-234.
[7]	宋嘉豪, 王文. 斯特林发动机与高温热管耦合运行特性研究[J]. 化工学报, 2023, 74(S1): 287-294.
[8]	张思雨, 殷勇高, 贾鹏琦, 叶威. 双U型地埋管群跨季节蓄热特性研究[J]. 化工学报, 2023, 74(S1): 295-301.
[9]	晁京伟, 许嘉兴, 李廷贤. 基于无管束蒸发换热强化策略的吸附热池的供热性能研究[J]. 化工学报, 2023, 74(S1): 302-310.
[10]	程成, 段钟弟, 孙浩然, 胡海涛, 薛鸿祥. 表面微结构对析晶沉积特性影响的格子Boltzmann模拟[J]. 化工学报, 2023, 74(S1): 74-86.
[11]	李艺彤, 郭航, 陈浩, 叶芳. 催化剂非均匀分布的质子交换膜燃料电池操作条件研究[J]. 化工学报, 2023, 74(9): 3831-3840.
[12]	王玉兵, 李杰, 詹宏波, 朱光亚, 张大林. R134a在菱形离散肋微小通道内的流动沸腾换热实验研究[J]. 化工学报, 2023, 74(9): 3797-3806.
[13]	齐聪, 丁子, 余杰, 汤茂清, 梁林. 基于选择吸收纳米薄膜的太阳能温差发电特性研究[J]. 化工学报, 2023, 74(9): 3921-3930.
[14]	李科, 文键, 忻碧平. 耦合蒸气冷却屏的真空多层绝热结构对液氢储罐自增压过程的影响机制研究[J]. 化工学报, 2023, 74(9): 3786-3796.
[15]	何松, 刘乔迈, 谢广烁, 王斯民, 肖娟. 高浓度水煤浆管道气膜减阻两相流模拟及代理辅助优化[J]. 化工学报, 2023, 74(9): 3766-3774.

方形微通道内超临界CO₂流动换热特性研究

Heat transfer characteristics of supercritical CO₂ in square microchannels

RichHTML

PDF (PC)

可视化

摘要/Abstract

引用本文

使用本文

图/表 16

参考文献 36

相关文章 15

编辑推荐 0

Metrics

本文评价