Heat storage characteristic and structure optimum inrectangular unit

doi:10.19799/j.cnki.2095-4239.2020.0035

Abstract

Abstract:

The melting process of paraffin wax in rectangular unit is simulated by using FLUENT software. The effects of different upper geometry sizes and different wall temperatures on the melting process of different rectangular units are studied separately. The criterion relations between the liquid fraction β and the dimensionless number Fo, Ste, and Ra are obtained by nonlinear fitting. The scheme and basis are provided for optimizing the overall melting rate of PCM (phase change material) in the rectangular unit. The results show that, during the paraffin melting process, the time proportion of natural convection as the dominant heat transfer method increases first and then decreases as the size of the upper part of the rectangular unit increases. The enhancement of heat transfer by natural convection increases with the increase of the unit upper size. However, the average heat storage rate first increases and then decreases with the increase of the upper size of the unit until it tends to be stable, and there is an optimal value. During the paraffin melting process, the time proportion of natural convection as the dominant heat transfer method increases first and then decreases as the size of the upper part of the rectangular unit increases. The temperature difference is one of the key factors affecting the melting of PCM. The temperature difference is increased from 43 °C to 53 °C, and then from 53 °C to 63 °C, as a consequence of this, the melting time is shortened by 14.63% and 24.26% respectively.

Key words: PCM, heat transfer enhancement, natural convection, optimization, numerical simulation

CLC Number:

TQ 051.5

ZHOU Huilin, QIU Yan. Heat storage characteristic and structure optimum inrectangular unit[J]. Energy Storage Science and Technology, 2020, 9(4): 1082-1090.

Figures/Tables 16

Fig.1

Table 1

Fig.2

Fig.3

Fig.4

Fig.5

Table 2

Table 3

Fig.6

Table4

Fig.7

Fig.8

Fig.9

Fig.10

Fig.11

Fig.12

References 23

1	DING N, DUAN J, XUE S, et al. Overall review of peaking power in China: status quo, barriers and solutions[J]. Renewable & Sustainable Energy Reviews, 2014, 42: 503-516.
2	刘树林, 钟世民, 陶翠翠, 等. 相变储能材料的研制与封装应用研究现状及展望[J]. 建筑热能通风空调, 2010, 29(6): 11-15.
	LIU Shulin, ZHONG Shimin, TAO Cuicui, et al. The Study situation and prospect of the manufacture and encapsulated application of phase-change energy storage material[J]. Building Energy & Environment, 2010, 29(6): 11-15.
3	张宇, 俞国勤, 施明融, 等. 电力储能技术应用前景分析[J]. 华东电力, 2008(4): 91-93.
	ZHANG Yu, YU Guoqin, SHI Mingrong, et al. Review of energy storage systems[J]. East China Electric Power, 2008(4): 91-93.
4	崔武军, 吴玉庭, 熊亚选, 等. 低熔点熔盐蓄热罐内温度分布与散热损失实验[J]. 化工学报, 2014, 65(S1): 162-167.
	CUI Wujun, WU Yuting, XIONG Yaxuan, et al. Temperature distribution and heat loss experiments of low melting point molten salt heat storage tank[J]. CIESC Journal, 2014, 65(S1): 162-167.
5	程友良, 王月坤, 张夏, 等. 新型太阳能混合蓄热罐的放热特性[J]. 化工进展, 2018, 37(5): 1718-1725.
	CHENG Youliang, WANG Yuekun, ZHANG Xia, et al. Heat release characteristics of new solar hybrid heat storage tank[J]. Chemical Industry and Engineering Progress, 2018, 37(5): 1718-1725.
6	孟强, 陈梦东, 胡晓, 等. 管内熔融盐强制对流传热的数值模拟[J]. 储能科学与技术, 2019, 8(3): 544-550.
	MENG Qiang, CHEN Mengdong, HU Xiao, et al. Numerical simulation of forced convective heat transfer of molten salt in tubes[J]. Energy Storage Science and Technology, 2019, 8(3): 544-550.
7	SHARMA A, TYAGI V V, CHEN C R, et al. Review on thermal energy storage with phase change materials and applications[J]. Renewable & Sustainable Energy Reviews, 2009, 13(2): 318-345.
8	孟锋, 安青松, 郭孝峰, 等. 蓄热过程强化技术的应用研究进展[J]. 化工进展, 2016, 35(5): 1273-1281.
	MENG Feng, AN Qingsong, GUO Xiaofeng, et al. Research progress in application of heat storage enhancement technology[J]. Chemical Industry and Engineering Progress, 2016, 35(5): 1273-1281.
9	徐治国, 赵长颖, 纪育楠, 等. 中低温相变蓄热的研究进展[J]. 储能科学与技术, 2014, 3(3): 179-190.
	XU Zhiguo, ZHAO Changying, JI Yunan, et al. State-of-the-art of phase-change thermal storage at middle-low temperature[J]. Energy Storage Science and Technology, 2019, 8(3): 544-550.
10	YUAN Yanping, CAO Xiaoling, BAI Li, et al. Melting behaviors of capric acid in rectangular enclosure[J]. Journal of Southwest Jiaotong University, 2012, 47(2): 236-240.
11	ASSIS E, KATSMAN L, ZISKIND G, et al. Numerical and experimental study of melting in a spherical shell[J]. International Journal of Heat & Mass Transfer, 2007, 50(9/10): 1790-1804.
12	HOSSEINIZADEH S F, DARZI A R. Unconstrained melting inside a sphere[J]. International Journal of Thermal Sciences, 2013, 63(63): 55-64.
13	NG K W, GONG Z X, MUJUMDAR A S. Melting of a phase change material in concentric horizontal annuli of arbitrary cross-section[J]. Applied Thermal Engineering, 2000, 20: 893-912.
14	刘泛函, 王仕博, 王华, 等. 圆柱形相变蓄热单元性能的理论与数值研究[J]. 太阳能学报, 2015, 36(3): 575-580.
	LIU Fanhan, WANGShibo, WANG Hua, et al. Theoretical cylindrical phase change thermal storage unit performance and numerical study[J]. Acta Energiae Solaris Sinica, 2015, 36(3): 575-580.
15	胡春妍, 袁艳平, 曹晓玲, 等. 环形单元内月桂酸熔化过程的传热特性[J]. 化工学报, 2014, 65(S2): 71-77.
	HU Chunyan, YUAN Yanping, CAO Xiaoling, et al. Mechanism of heat transfer during melting of lauric acid in horizontal annulus[J]. CIESC Journal, 2014, 65(S2): 71-77.
16	REGIN A F, SOLANKI S C, SAINI J S. Heat transfer characteristics of thermal energy storagesystem using PCM capsules: A review[J]. Renewable & Sustainable Energy Reviews, 2008, 12(9): 2438-2458.
17	WANG Yifei, WANG Liang, XIE Ninging, et al. Experimental study on the melting and solidification behavior of erythritol in a vertical shell-and-tube latent heat thermal storage unit[J]. International Journal of Heat & Mass Transfer, 2016, 99: 770-781.
18	CHANG J, DENNIS Y C L, WU C Z. A review on the energy production, consumption, and prospect of renewable energy in China[J]. Renewable &Sustainable Energy Reviews, 2003, 7(5): 453-468.
19	彭冬华, 陈振乾, 施明恒. 泡沫金属内相变材料融化传热过程的数值模拟[J]. 工程热物理学报, 2009, 30(6): 1025-1028.
	PENG Donghua, CHEN Zhenqian, SHI Mingheng. Numerical simulation of phase change material thawing process in metallicfoams[J]. Journal of Engineering Thermophysics, 2009, 30(6): 1025-1028.
20	毛前军.管壳式太阳能相变蓄热装置的数值模拟[C]//中国工程热物理学会传热传质分会， 2017.
	MAO Qianjun. Numerical simulation of shell and tube solar energy phase change thermal storage device [C]//Chinese Society of Engineering Thermophysics, Heat and Mass Transfer, 2017.
21	郭英利. 石蜡圆管外相变蓄热与释热规律的研究[D]. 天津: 天津大学, 2008.
	GUO Yingli． Study on the heat storage and heat releaseby paraffin phase change outside the pipe[D]. Tianjin: TianjinUniversity， 2008．
22	周慧琳, 邱燕. 矩形蓄热单元内石蜡的相变传热特性[J]. 山东大学学报（工学版）, 2019, 49(4): 1-9.
	ZHOU Huilin, QIU Yan. Phase change characteristics of paraffin in rectangular storage unit[J]. Journal of Shandong University(Engineering Science), 2019, 49(4): 1-9.
23	龙伟月, 曹晓玲, 袁艳平, 等. 内径尺寸对环形相变蓄热单元熔化特性影响规律的数值分析[J]. 太阳能学报, 2018, 39(6): 1502-1510.
	LONG Weiyue, CAO Xiaoling, YUAN Yanping, et al. Numerical analysis of effect of inner diameter on melting characteristics of annular phase change heat storage unit[J]. Acta Energiae Solaris Sinica, 2018, 39(6): 1502-1510.

相变温度/K	相变潜热/kJ·kg^-1	密度/kg·m^-3		热导率/W·(m·K)^-1		比热容/kJ·(kg·K)^-1
相变温度/K	相变潜热/kJ·kg^-1	固态	液态	固态	液态	固态	液态
319.68	141.91	916	776	0.27	0.11	1.7	2.5

序号	H₂=H₃/mm	N=H₁/H₂	PCM完全熔化时间/s
1	20	1	4711
2	20	1.5	4801
3	20	2	6057
4	20	4	9152
5	20	6	12602

N	PCM完全熔化时间/s	自然对流为传热主导方式时间/s	自然对流为主占熔化总时间比例	单元内平均努塞尔数的平均值
1	4711	600	12.74%	23.81
1.5	4801	841	17.49%	27.75
2	6057	1020	16.84%	24.27
4	9152	840	9.18%	23.92
6	12602	960	7.62%	23.91

[1]	Wei ZENG, Junjie XIONG, Jianlin LI, Suliang MA, Yiwen WU. Optimal configuration of energy storage power station in multi-energy system based on weight adaptive whale optimization algorithm [J]. Energy Storage Science and Technology, 2022, 11(7): 2241-2249.
[2]	Guohui FENG, Tianyu WANG, Gang WANG. A simulation analysis on the effect of encapsulation mode on the heat storage and release performance of phase change water tank [J]. Energy Storage Science and Technology, 2022, 11(7): 2161-2176.
[3]	Wenlan YE, Ming ZHAO, Mingyu HU, Yang TIAN. Analysis of heat storage and release performance of tube bundle phase change heat accumulator [J]. Energy Storage Science and Technology, 2022, 11(7): 2151-2160.
[4]	Zhongbo LI, Jingxiao HAN, Chengcheng WANG, Hui YANG, Na YANG, Shaowu YIN, Li WANG, Lige TONG, Zhiwei TANG, Yulong DING. Simulation and the parameter influence relationship of the discharging process in a thermochemical reactor [J]. Energy Storage Science and Technology, 2022, 11(7): 2133-2140.
[5]	Liande LIU, Jiang HE, Jiaxu ZHOU, Cuiping LI, Kaiqiang LI, Xingxu ZHU, Gangiu YAN, Junhui LI. Optimization control strategy of pumped storage station in power system with high proportion wind/photovoltaic power [J]. Energy Storage Science and Technology, 2022, 11(7): 2197-2205.
[6]	WU Xiaoling, ZHOU Tao, LIU Yuzhao, DU Yanping, CHEN Huiping, LI Shun. Numerical study on cooling enhancement of micro devices by designing turbulence based hollow micro pin-fin arrays with lateral holes [J]. Energy Storage Science and Technology, 2022, 11(6): 1980-1987.
[7]	Shuai HAN, Leping SUN, Jianbin LU, Xiaoxuan GUO. Multi-objective optimal dispatch strategy of gas-electric interconnected virtual power plant interval with electric vehicles [J]. Energy Storage Science and Technology, 2022, 11(5): 1428-1436.
[8]	Xinyi WANG, Weijie LI, Chao HAN, Huakun LIU, Shixue DOU. Challenges and optimization strategies of the anode of aqueous zinc-ion battery [J]. Energy Storage Science and Technology, 2022, 11(4): 1211-1225.
[9]	Luyu GAN, Rusong CHEN, Hongyi PAN, Siyuan WU, Xiqian YU, Hong LI. Multiscale research strategy of lithium ion battery safety issue： Experimental and simulation methods [J]. Energy Storage Science and Technology, 2022, 11(3): 852-865.
[10]	Shangyu ZHAO, Zhen ZHANG, Baoyuan WANG, Quhu ZENG. An engineering method for detection of problems of lithium iron phosphate batteries [J]. Energy Storage Science and Technology, 2022, 11(2): 643-651.
[11]	Ang LI, Xiaomeng LI, Lin YANG, Han WANG, Junfan XIANG, Yuhan LIU. Compression force calculation of redox flow battery [J]. Energy Storage Science and Technology, 2022, 11(2): 609-614.
[12]	Yongxue ZHANG, Zixi WANG, Bohui LU, Shengqi YANG, Hongyu ZHAO. Enhancement of charging and discharging performance of a latent-heat thermal-energy storage unit using snowflake-shaped fins [J]. Energy Storage Science and Technology, 2022, 11(2): 521-530.
[13]	Xiaobin XU, Yefei XU, Hengyun ZHANG, Shunliang ZHU, Haifeng WANG. Multiobjective optimization of thermal performance and grouping efficiency for air cooling battery module [J]. Energy Storage Science and Technology, 2022, 11(2): 553-562.
[14]	Xiaoguang ZHANG, Xiaonan PAN, Jinming LI, Li LIU, Yan HE. Effect of battery arrangement on the phase change thermal management performance of lithium-ion battery packs [J]. Energy Storage Science and Technology, 2022, 11(1): 127-135.
[15]	Huihui YANG, Li ZENG, Bo TANG, Xiaoqing WANG, Yong LU. Experimental study on an EG/paraffin composite thermal storage material and its feasibility for off-peak power heating utilization [J]. Energy Storage Science and Technology, 2022, 11(1): 19-29.