一种新型环路重力热管的数值模拟和性能优化

doi:10.11949/0438-1157.20221530

化工学报 ›› 2023, Vol. 74 ›› Issue (2): 721-734.DOI: 10.11949/0438-1157.20221530

一种新型环路重力热管的数值模拟和性能优化

陈建勋¹^,²(), 刘金平¹^,²^,³(), 许雄文¹^,², 余银豪¹^,²

^1.华南理工大学电力学院，广东广州 510640
^2.华南理工大学广东省高效清洁能源利用重点实验室，广东广州 510640
^3.华南理工大学亚热带建筑科学国家重点实验室，广东广州 510640

收稿日期:2022-11-23 修回日期:2023-02-04 出版日期:2023-02-05 发布日期:2023-03-21
通讯作者: 刘金平
作者简介:陈建勋（1994—），男，博士研究生，171203147@qq.com
基金资助:
国家自然科学基金项目(51976063);广东省自然科学基金项目(2019A1515011253)

Numerical simulation and performance optimization of a new loop gravity heat pipe

Jianxun CHEN¹^,²(), Jinping LIU¹^,²^,³(), Xiongwen XU¹^,², Yinhao YU¹^,²

^1.School of Electric Power, South China University of Technology, Guangzhou 510640, Guangdong, China
^2.Guangdong Province Key Laboratory of Efficient and Clean Energy Utilization, South China University of Technology, Guangzhou 510640, Guangdong, China
^3.State Key Laboratory of Subtropical Building Science, South China University of Technology, Guangzhou 510640, Guangdong, China

Received:2022-11-23 Revised:2023-02-04 Online:2023-02-05 Published:2023-03-21
Contact: Jinping LIU

摘要/Abstract

摘要：

研究了一种新型的环路重力热管（LGHP），并提出一种基于VOF方法的简化两相流数值模型，能够有效地模拟热管蒸发器内部气泡的产生和干涸区的位置，从而研究蒸发器内部工质的流动特性。在数值模拟的基础上改进了蒸发器的流道结构，以延缓水平放置时蒸发器干涸区的出现。通过实验验证发现改进后蒸发器的传热性能得到了很大的提高，蒸发器中制冷剂的液相积存量得以提升，使其极限热通量（CHF）提高到140 kW/m²（加热功率2000.7 W），为改进前CHF的两倍。证明该简化模型在模拟干涸区位置方面具有准确性，可以为进一步的设计和改进平板蒸发器流道结构提供参考。

关键词: 环路重力热管, 极限热通量, 干涸区, 池沸腾

Abstract:

A new loop gravity heat pipe (LGHP) is researched and a simplified two-phase flow numerical model based on VOF method is proposed to study the flow characteristics of the working fluid in the evaporator, which can effectively simulate the generation of bubbles and the location of the dry area in the evaporator of LGHP. Based on the numerical simulation, the channel structure of the evaporator is improved to delay the appearance of the dry zone of the evaporator when it is placed horizontally. Through experimental verification, it is found that the heat transfer performance of the improved evaporator has been greatly improved, and the liquid phase storage capacity of the refrigerant in the evaporator has been improved, which double its critical heat flux (CHF) to 140 kW/m² (heating power 2000.7 W). It is proved that the simplified model is accurate in simulating the location of the dry area, and can provide a reference for further design and improvement of the flow channel structure of the flat evaporator.

Key words: loop gravity-assisted heat pipe, critical heat flux, dry area, pool boiling

中图分类号:

TK 172.4

陈建勋, 刘金平, 许雄文, 余银豪. 一种新型环路重力热管的数值模拟和性能优化[J]. 化工学报, 2023, 74(2): 721-734.

Jianxun CHEN, Jinping LIU, Xiongwen XU, Yinhao YU. Numerical simulation and performance optimization of a new loop gravity heat pipe[J]. CIESC Journal, 2023, 74(2): 721-734.

图/表 24

图1 LGHP实验系统图

Fig.1 Schematic diagram of LGHP

表1 蒸发器结构参数

Table 1 The structure of evaporator

Parameter	Value
heating block
block size	120 mm×120 mm×50 mm
heating rod size	100 mm×10 mmϕ
evaporator
whole size	140 mm×120 mm×21 mm
top wall thickness	3 mm
side wall thickness	5.5 mm
bottom wall thickness	3 mm
square column size	3 mm×3 mm×15 mm
square column distance	3 mm
inlet diameter (O/I) length	8.5 mm/6.35 mm 53 mm
outlet diameter (O/I) length upward tube	8.5 mm/6.35 mm 65 mm
diameter (O/I)	10 mm/6.5 mm
length	2100 mm
downward tube
diameter (O/I) length	10 mm/6.5 mm 1800 mm

表2 R134a部分热物性参数

Table 2 Some thermal physical parameters of R134a

饱和温度T_s/℃	饱和压力p_s/MPa	液体密度ρ_l /(kg/m³)	气体密度ρ_g/(kg/m³)	汽化潜热r/(kJ/kg)
0	0.2928	1294.80	14.43	198.60
10	0.4146	1261.00	20.23	190.74
20	0.5717	1225.30	27.78	182.28
30	0.7702	1187.50	37.54	173.10
40	1.0166	1146.70	50.09	163.02

图2 改进前蒸发器结构

Fig.2 Structure of evaporator before improvement

图3 竖管降膜冷凝器示意图

Fig.3 Schematic diagram of vertical tube falling film condenser

图4 测温点分布

Fig.4 Distribution of temperature measuring points

表3 不确定度分析（置信概率95%）

Table 3 Uncertainty analysis （confidence level 95%）

Parameter

Uncertainty (u)

T-type thermocouple, T

K-type thermocouple, T

0.5 K

1.0 K

Pressure sensor, p

Power sensor, Q

7500 Pa

8.8 W

图5 蒸发器温度分布

Fig.5 Temperature distribution diagram of evaporator

表4 几何模型的设置

Table 4 Settings of geometric model

Wall material	Working fluid	$X m i n / X m a x$	$Y m i n / Y m a x$	$Z m i n / Z m a x$
copper	R-134a	5.5 mm/134.5 mm	4.5 mm/115.5 mm	0 mm/15 mm

表4 几何模型的设置

Table 4 Settings of geometric model

Wall material	Working fluid	$X m i n / X m a x$	$Y m i n / Y m a x$	$Z m i n / Z m a x$
copper	R-134a	5.5 mm/134.5 mm	4.5 mm/115.5 mm	0 mm/15 mm

图6 蒸发器网格模型

Fig.6 The mesh model of evaporator

图7 网格独立性验证

Fig.7 Verification of mesh independence

表5 CFD模型设置

Table 5 CFD model settings

CFD模型参数设置项	设置值
求解器类型	Pressure-based
算法（压力-速度耦合）	PISO
空间离散化
Gradient	Least square cell based
Pressure	PRESTO
Density	Second order upwind
Momentum	Second order upwind
Volume fraction	Geo-reconstruct
Turbulent kinetic energy	First order upwind
Turbulent dissipation rate	First order upwind
Energy	Second order upwind
时间步长离散化	First order implicit
残差
Continuity X-velocity Y-velocity Z-velocity Energy k $ε$	1×10^-3 1×10^-4 1×10^-4 1×10^-4 1×10^-8 1×10^-4 1×10^-4
时间步长	0.0002s
每个时间步长的最大迭代次数	40
湍流模型	k-ε realizable
湍流动能传输的有效Prandtl数	0.8
湍流耗散率传输的有效Prandtl数	0.8
能量的湍流Prandtl数	1

表5 CFD模型设置

Table 5 CFD model settings

CFD模型参数设置项	设置值
求解器类型	Pressure-based
算法（压力-速度耦合）	PISO
空间离散化
Gradient	Least square cell based
Pressure	PRESTO
Density	Second order upwind
Momentum	Second order upwind
Volume fraction	Geo-reconstruct
Turbulent kinetic energy	First order upwind
Turbulent dissipation rate	First order upwind
Energy	Second order upwind
时间步长离散化	First order implicit
残差
Continuity X-velocity Y-velocity Z-velocity Energy k $ε$	1×10^-3 1×10^-4 1×10^-4 1×10^-4 1×10^-8 1×10^-4 1×10^-4
时间步长	0.0002s
每个时间步长的最大迭代次数	40
湍流模型	k-ε realizable
湍流动能传输的有效Prandtl数	0.8
湍流耗散率传输的有效Prandtl数	0.8
能量的湍流Prandtl数	1

图8 不同加热功率下蒸发器底面温度分布

Fig.8 The distribution of temperature in evaporator under different heating powers

图9 数值模拟蒸发器内液体流动结果

Fig.9 Numerical simulation of liquid flow in evaporator

图10 数值模拟结果和实验结果对比

Fig.10 The simulation result compared with the actual temperature measurement

图11 不同加热功率下蒸发器内部工质流动云图

Fig.11 The simulation results of evaporator under different heating powers

图12 改进后蒸发器结构

Fig.12 The structure of the improved evaporator

图13 不同加热功率下改进后蒸发器内部工质流动云图

Fig.13 The simulation results of improved evaporator under different heating powers

图14 不同加热功率下改进后蒸发器底面温度分布

Fig.14 The distribution of temperature in the improved evaporator under different heating powers

图15 数值模拟结果和实验结果对比

Fig.15 The simulation result compared with the actual temperature measurement

图16 改进后蒸发器温度分布

Fig.16 Temperature distribution diagram of the improved evaporator

图17 改进前后蒸发器平均温度

Fig.17 Average temperature of the evaporator before and after improvement

图18 改进前后蒸发器传热系数

Fig.18 Heat transfer coefficient of evaporator before and after improvement

图19 垂直放置时改进前后蒸发器传热系数

Fig.19 Heat transfer coefficient of evaporator placed vertically before and after improvement

参考文献 31

1	Zhang H N, Shao S Q, Tian C Q, et al. A review on thermosyphon and its integrated system with vapor compression for free cooling of data centers[J]. Renewable and Sustainable Energy Reviews, 2018, 81: 789-798.
2	Samba A, Louahlia-Gualous H, Le Masson S, et al. Two-phase thermosyphon loop for cooling outdoor telecommunication equipments[J]. Applied Thermal Engineering, 2013, 50(1): 1351-1360.
3	曲燕. 环路热管技术的研究热点和发展趋势[J]. 低温与超导, 2009, 37(2): 7-14.
	Qu Y. Hot study and development trend of loop heat pipes[J]. Cryogenics and Superconductivity, 2009, 37(2): 7-14
4	Bai L Z, Guo J H, Lin G P, et al. Steady-state modeling and analysis of a loop heat pipe under gravity-assisted operation[J]. Applied Thermal Engineering, 2015, 83: 88-97.
5	Tuhin A R, Huynh P H, Htoo K Z, et al. Thermal performance comparison of flat plate evaporator loop heat pipe operating between horizontal condition and gravity assisted condition[J]. Journal of Physics: Conference Series, 2018, 1086: 012013.
6	Zhu K, Li X Q, Li H L, et al. Experimental and theoretical study of a novel loop heat pipe[J]. Applied Thermal Engineering, 2018, 130: 354-362
7	战洪仁, 惠尧, 吴众. 闭式热虹吸管强化传热研究进展[J]. 化工进展, 2017, 36(8): 2764-2775
	Zhan H R, Hui Y, Wu Z. Research progress on heat transfer enhancement in closed thermosyphon[J]. Chemical Industry and Engineering Progress, 2017, 36(8): 2764-2775
8	张先锋. 平板式环路热管性能的实验[J]. 化工进展, 2012, 31(6): 1200-1205.
	Zhang X F. Experimental investigation on the performance of loop heat pipe with flat evaporator[J]. Chemical Industry and Engineering Progress, 2012, 31(6): 1200-1205
9	赵忠超, 周根明, 陈育平, 等. 环路热管理论研究进展[J]. 江苏科技大学学报(自然科学版), 2009, 23(5): 416-420.
	Zhao Z C, Zhou G M, Chen Y P, et al. Progress in loop heat pipe theory[J]. Journal of Jiangsu University of Science and Technology (Natural Science Edition), 2009, 23(5): 416-420
10	梁灵娇, 刘金平, 许雄文. 用于高热通量电子散热的平板环路重力热管[J]. 化工学报, 2018, 69(10): 4231-4238.
	Liang L J, Liu J P, Xu X W. Novel flat plate evaporator of loop gravity assisted heat pipe for high heat flux electronic cooling[J]. CIESC Journal, 2018, 69(10): 4231-4238
11	Gai D X, Liu Z C, Liu W, et al. Experimental investigation of temperature oscillation in miniature loop heat pipe [J]. AIP Conference Proceedings, 2010, 1207(1): 465-470
12	孙志坚. 电子器件回路型热管散热器的数值模拟与试验研究[D]. 杭州: 浙江大学, 2007.
	Sun Z J. Numerical simulation and experimental studies on loop heat pipe radiator for electronic device cooling[D]. Hangzhou: Zhejiang University, 2007.
13	Tsai T E, Wu H H, Chang C C, et al. Two-phase closed thermosyphon vapor-chamber system for electronic cooling[J]. International Communications in Heat and Mass Transfer, 2010, 37(5): 484-489.
14	陈彬彬, 刘伟, 刘志春, 等. 平板式小型环路热管的实验研究[J]. 宇航学报, 2011, 32(4): 953-958.
	Chen B B, Liu W, Liu Z C, et al. Experimental study on miniature loop heat pipe with flat-plate evaporator[J]. Journal of Astronautics, 2011, 32(4): 953-958.
15	Liu Z C, Wang D D, Jiang C, et al. Experimental study on loop heat pipe with two-wick flat evaporator[J]. International Journal of Thermal Sciences, 2015, 94: 9-17.
16	韩晓红, 闵旭伟, 李鹏, 等. 一种利用气泡泵效应重力辅助回路热管的实验研究[J]. 西安交通大学学报, 2012, 46(3): 9-14.
	Han X H, Min X W, Li P, et al. Experimental study on an thermosyphon loop with bubble pump effect[J]. Journal of Xi'an Jiaotong University, 2012, 46(3): 9-14
17	Hong S H, Zhang X Q, Wang S F, et al. Experiment study on heat transfer capability of an innovative gravity assisted ultra-thin looped heat pipe[J]. International Journal of Thermal Sciences, 2015, 95: 106-114.
18	Wang D D, Liu Z C, Shen J, et al. Experimental study of the loop heat pipe with a flat disk-shaped evaporator[J]. Experimental Thermal and Fluid Science, 2014, 57: 157-164.
19	Liu Z C, Gai D X, Li H, et al. Investigation of impact of different working fluids on the operational characteristics of miniature LHP with flat evaporator[J]. Applied Thermal Engineering, 2011, 31(16): 3387-3392.
20	李志崇. 平板型双毛细芯蒸发器环路热管的实验研究[D]. 武汉: 华中科技大学, 2015.
	Li Z C. Experimental study of the double capillary wick evaporator flat plate type loop heat pipes[D]. Wuhan: Huazhong University of Science and Technology, 2015.
21	柏立战, 林贵平, 张红星. 重力辅助环路热管稳态运行特性的实验研究[J]. 航空学报, 2008, 29(5): 1112-1117.
	Bai L Z, Lin G P, Zhang H X. Experimental study on steady-state operating characteristics of gravity-assisted loop heat pipes[J]. Acta Aeronautica et Astronautica Sinica, 2008, 29(5): 1112-1117.
22	Tu Z K, Liu Z C, Liu C, et al. Heat and mass transfer in a flat disc-shaped evaporator of a miniature loop heat pipe[J]. Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering, 2009, 223(6): 609-618.
23	Alizadehdakhel A, Rahimi M, Alsairafi A A. CFD modeling of flow and heat transfer in a thermosyphon[J]. International Communications in Heat and Mass Transfer, 2010, 37(3): 312-318.
24	Fadhl B, Wrobel L C, Jouhara H. CFD modelling of a two-phase closed thermosyphon charged with R134a and R404a[J]. Applied Thermal Engineering, 2015, 78: 482-490.
25	Wang X Y, Wang Y F, Chen H J, et al. A combined CFD/visualization investigation of heat transfer behaviors during geyser boiling in two-phase closed thermosyphon[J]. International Journal of Heat and Mass Transfer, 2018, 121: 703-714.
26	Jiang Y Y, Osada H, Inagaki M, et al. Dynamic modeling on bubble growth, detachment and heat transfer for hybrid-scheme computations of nucleate boiling[J]. International Journal of Heat and Mass Transfer, 2013, 56(1/2): 640-652.
27	Abadi N R, Ahmadpour A, Meyer J P. Numerical simulation of pool boiling on smooth, vertically aligned tandem tubes[J]. International Journal of Thermal Science, 2018, 132: 628-644.
28	Kunkelmann C, Stephan P. Numerical simulation of the transient heat transfer during nucleate boiling of refrigerant HFE-7100[J]. International Journal of Refrigeration, 2010, 33(7): 1221-1228.
29	Sato Y, Niceno B. Nucleate pool boiling simulations using the interface tracking method: boiling regime from discrete bubble to vapor mushroom region[J]. International Journal of Heat and Mass Transfer, 2017, 105: 505-524.
30	Ruan J G, Liu J P, Xu X W, et al. Experimental study of an R290 split-type air conditioner using a falling film condenser[J]. Applied Thermal Engineering, 2018, 140: 325-333.
31	Moffat R J. Describing the uncertainties in experimental results[J]. Experimental Thermal and Fluid Science, 1988, 1(1): 3-17.

[1]	王海, 林宏, 王晨, 许浩洁, 左磊, 王军锋. 高压静电场强化多孔介质表面沸腾传热特性研究[J]. 化工学报, 2023, 74(7): 2869-2879.
[2]	林石泉, 赵雅鑫, 吕中原, 赖展程, 胡海涛. 亲疏水性对泡沫金属池沸腾换热特性的影响[J]. 化工学报, 2021, 72(S1): 295-301.
[3]	曹海亮, 张红飞, 左潜龙, 安琪, 张子阳, 刘红贝. 梯形微槽道表面池沸腾换热性能研究[J]. 化工学报, 2021, 72(8): 4111-4120.
[4]	牟帅, 赵长颖, 徐治国. 局部表面改性紫铜方柱阵列池沸腾传热特性和机理[J]. 化工学报, 2019, 70(4): 1291-1301.
[5]	陈宏霞, 孙源, 宫逸飞, 黄林滨. 单晶硅表面池沸腾可视化测量及数据分析[J]. 化工学报, 2019, 70(4): 1309-1317.
[6]	黄瑞连, 赵长颖, 徐治国. 梯度金属泡沫池沸腾过程中气泡脱离特性[J]. 化工学报, 2018, 69(7): 2890-2898.
[7]	梁灵娇, 刘金平, 许雄文. 用于高热通量电子散热的平板环路重力热管[J]. 化工学报, 2018, 69(10): 4231-4238.
[8]	冀文涛, 张定才, 赵创要, 何雅玲, 陶文铨. 高热通量水平管外池沸腾传热[J]. 化工学报, 2016, 67(S1): 28-32.
[9]	魏进家, 张永海. 柱状微结构表面强化沸腾换热研究综述[J]. 化工学报, 2016, 67(1): 97-108.
[10]	莫冬传, 张晖, 吕树申. TiO₂纳米管阵列表面的池沸腾实验[J]. 化工学报, 2014, 65(S1): 308-315.
[11]	朱冬生, 周吉成, 霍正齐, 李军, 李燕. 满液式蒸发器中螺旋扁管的池沸腾传热[J]. 化工学报, 2013, 64(4): 1151-1156.
[12]	程云, 李菊香, 莫光东. 水在开孔泡沫铜中的池沸腾传热特性[J]. 化工学报, 2013, 64(4): 1231-1235.
[13]	胡自成，王谦，谢强，宋新南. 表面活性剂水溶液池热核沸腾传热的试验研究[J]. 化工进展, 2013, 32(07): 1510-1514.
[14]	邓鹏，陶金亮，魏峰，史晓平. 纳米管阵列表面池沸腾强化传热实验[J]. 化工进展, 2012, 31(10): 2172-2175.
[15]	黄金印, 屈治国, 李定国, 徐治国, 陶文铨. 紫铜纤维毡水平表面的池沸腾换热性能 [J]. 化工学报, 2011, 62(S1): 26-30.

一种新型环路重力热管的数值模拟和性能优化

Numerical simulation and performance optimization of a new loop gravity heat pipe

RichHTML

PDF (PC)

可视化

摘要/Abstract

引用本文

使用本文

图/表 24

参考文献 31

相关文章 15

编辑推荐

Metrics

本文评价