Preparation and thermal energy storage properties of high heat conduction expanded graphite/palmitic acid form-stable phase change materials

doi:10.11949/0438-1157.20190179

Abstract

Abstract:

A kind of composite phase change materials (PCMs) was prepared by the process of “melting blend - solidification and form-stable” to improve the comprehensive performance of PCMs. Palmitic acid (PA) is used as PCM and expanded graphite (EG) is used for the supporting material. Twenty-one kinds of form-stable composite PCMs were prepared with different contents of EG. The morphologies and structures were characterized microscopically by SEM. On this basis, heat transfer performance analysis, thermophysical test, thermal stability test and heat storage performance analysis were conducted. SEM morphological characterization showed that PA could be absorbed into the pores of EG and the distribution was uniform. DSC test results revealed that the melting enthalpy of PCMs is 193.01 J/g with the 70%(mass) PA corresponding to the melting point of 61.08℃. The melting enthalpy of pure PA is 275.35 J/g corresponding to the melting point of 59.53℃. The thermal conductivity of the PCMs is significantly improved by the addition of EG. When the sample density was 900 kg/m³ and the content of EG was 30%(mass), the thermal conductivity of the composite PCM is 14.09 W/(m·K), which is about 87 times higher than that of pure PA. Cycle stability tests were carried out, the results suggest the samples with 24% and 30% EG content have no any change in shape, and therefore show excellent cycle stability in repeating charging and discharging processes.

Key words: palmitic acid, expanded graphite, form-stable, phase change materials (PCMs), preparation, thermal energy storage performance

摘要：

采用棕榈酸(palmitic acid, PA)作为相变材料，膨胀石墨(expanded graphite, EG)作为添加基质，通过“熔融共混-凝固定形”工艺制备了PA/EG定形复合相变材料以提高相变材料的综合性能。预测并制备了21种不同配比的定形复合相变材料，对其形貌结构和孔隙率进行了微观表征与理论分析，并在此基础上对样品进行了传热性能分析、热物性测试、热稳定性研究和储热性能分析。SEM形貌分析显示所使用工艺可使棕榈酸能较好地被吸附于膨胀石墨的孔隙结构并使之均匀分布；DSC测试结果表明定形复合相变材料[70%(质量) PA]的焓值为193.01 J/g，纯PA的焓值为275.35 J/g，对应于熔点分别为61.08℃和59.53℃。EG的添加，可有效提高相变材料的热导率。当样品密度为900 kg/m³，EG含量为30%(质量)时，定形复合相变材料的热导率为14.09 W/(m·K)，相比于纯PA[0.162 W/(m·K)]提高约87倍；对制备的样品进行50次循环稳定性实验，EG含量为24%(质量)和30%(质量)的样品形态均未出现明显变化，表现出良好的充放热循环稳定性。

关键词: 棕榈酸, 膨胀石墨, 定形, 相变材料, 制备, 储热性能

CLC Number:

TK 124

Shaofei WU, Ting YAN, Zihan KUAI, Weiguo PAN. Preparation and thermal energy storage properties of high heat conduction expanded graphite/palmitic acid form-stable phase change materials[J]. CIESC Journal, 2019, 70(9): 3553-3564.

吴韶飞, 闫霆, 蒯子函, 潘卫国. 高导热膨胀石墨/棕榈酸定形复合相变材料的制备及储热性能研究[J]. 化工学报, 2019, 70(9): 3553-3564.

Figures/Tables 15

Fig.1 Preparation procedure of PA/EG form-stable composite PCMs sample

Fig.2 PA/EG form-stable composite PCMs sample

Fig.3 Change of PA/EG form-stable composite PCMs density with porosity

Fig.4 PA/EG form-stable composite PCM samples with different proportions

Table1 PA/EG form-stable composite PCMs sample with different mass fractions of EG and different densities

方块密度/(kg/m³)	EG/%(mass)	质量/g	密度/(kg/m³)	样品序号
600	6	38.977	609	S1
	12	50.940	596	S2
	18	38.076	595	S3
	24	38.339	599	S4
	30	38.001	594	S5
700	6	44.530	696	S6
	12	44.539	696	S7
	18	44.596	697	S8
	24	44.679	698	S9
	30	44.730	699	S10
800	6	50.940	796	S11
	12	50.840	794	S12
	18	51.095	798	S13
	24	51.098	798	S14
	30	51.138	799	S15
900	6	—	—	—
	12	57.485	898	S16
	18	57.429	897	S17
	24	57.487	898	S18
	30	57.252	895	S19
1000	6	—	—	—
	12	—	—	—
	18	—	—	—
	24	63.847	998	S20
	30	63.620	994	S21

Fig.5 SEM image of EG and composite PCMs

Fig.6 DSC curves of pure PA and five different proportions of PA/EG form-stable composite PCM samples

Fig.7 Prediction and experimental curve of latent heat of PA/EG composite PCMs samples with EG mass fraction

Fig.8 Relation curve of supercooling degree of PA/EG form-stable PCMs with content of EG

Fig.9 Microstructure of PA/EG composite PCMs

Fig.10 Changes in horizontal and vertical thermal conductivity of PA/EG form-stable composite samples with sample density when content of EG is 30%(mass)

Fig.11 Curve of thermal conductivity with sample density

Fig.12 Relation curve of effective thermal conductivity change with cycle times

Fig.13 Relation curve of sample mass change with cycle times

Fig.14 Changes of sample morphology during charging/discharging process

References 38

1	Huang X , Alva G , Liu L . et al. Microstructure and thermal properties of cetyl alcohol/high density polyethylene composite phase change materials with carbon fiber as shape-stabilized thermal storage materials [J]. Applied Energy, 2017, 200: 19-27.
2	Kant K , Shukla A , Sharma A . Advancement in phase change materials for thermal energy storage applications [J]. Solar Energy Materials and Solar Cells, 2017, 172: 82-92.
3	Chandel S S , Agarwal T . Review of current state of research on energy storage, toxicity, health hazards and commercialization of phase changing materials [J]. Renewable and Sustainable Energy Reviews, 2017, 67: 581-596.
4	Tang Y , Jia Y , Alva G , et al . Synthesis, characterization and properties of palmitic acid/high density polyethylene/graphene nanoplatelets composites as form-stable phase change materials [J]. Solar Energy Materials and Solar Cells, 2016, 155: 421-429.
5	Lin Y , Zhu C , Alva G , et al . Palmitic acid/polyvinyl butyral/expanded graphite composites as form-stable phase change materials for solar thermal energy storage [J]. Applied Energy, 2018, 228:1801-1809.
6	Cárdenas B , León N . High temperature latent heat thermal energy storage: phase change materials, design considerations and performance enhancement techniques [J]. Renewable and Sustainable Energy Reviews, 2013, 27: 724-737.
7	Atinafu D G , Dong W , Huang X , et al . Introduction of organic-organic eutectic PCM in mesoporous N-doped carbons for enhanced thermal conductivity and energy storage capacity [J]. Applied Energy, 2018, 211: 1203-1215.
8	Ma G , Liu S , Xie S , et al . Binary eutectic mixtures of stearic acid- n-butyramide/n-octanamide as phase change materials for low temperature solar heat storage [J]. Applied Thermal Engineering, 2017, 111: 1052-1059.
9	Tay N H S , Liu M , Belusko M , et al . Review on transportable phase change material in thermal energy storage systems [J]. Renewable and Sustainable Energy Reviews, 2017, 75: 264-277.
10	Lin Y , Jia Y , Alva G , et al . Review on thermal conductivity enhancement, thermal properties and applications of phase change materials in thermal energy storage [J]. Renewable and Sustainable Energy Reviews, 2018, 82: 2730-2742.
11	Khan M A , Saidur R , Al-Sulaiman F A . A review for phase change materials (PCMs) in solar absorption refrigeration systems [J]. Renewable and Sustainable Energy Reviews, 2017, 76: 105-137.
12	Alva G , Liu L , Huang X , et al . Thermal energy storage materials and systems for solar energy applications[J]. Renewable and Sustainable Energy Reviews, 2017, 68: 693-706.
13	Souayfane F , Fardoun F , Biwole P H . Phase change materials (PCM) for cooling applications in buildings: a review [J]. Energy and Buildings [J]. 2016, 129: 396-431.
14	Miró L , Gasia J , Cabeza L F . Thermal energy storage (TES) for industrial waste heat (IWH) recovery: a review [J]. Applied Energy, 2016, 179: 284-301.
15	Cao R R , Li X , Chen S , et al . Fabrication and characterization of novel shape-stabilized synergistic phase change materials based on PHDA/GO composites [J]. Energy, 2017, 138: 157-166.
16	Xu Y , Li M J , Zheng Z J , et al . Melting performance enhancement of phase change material by a limited amount of metal foam: configurational optimization and economic assessment [J]. Applied Energy, 2018, 212: 868-880.
17	Wu S , Li T X , Yan T , et al . High performance form-stable expanded graphite/stearic acid composite phase change material for modular thermal energy storage [J]. International Journal of Heat and Mass Transfer, 2016, 102: 733-744.
18	Zhang Q , Luo Z , Guo Q , et al . Preparation and thermal properties of short carbon fibers/erythritol phase change materials [J]. Energy Conversion and Management, 2017, 136: 220-228.
19	Xu T , Chen Q , Huang G , et al . Preparation and thermal energy storage properties of D-mannitol/expanded graphite composite phase change material [J]. Solar Energy Materials and Solar Cells, 2016, 155: 141-146.
20	Karaipekli A , Biçer A , Sarı A , et al . Thermal characteristics of expanded perlite/paraffin composite phase change material with enhanced thermal conductivity using carbon nanotubes [J]. Energy Conversion and Management, 2017, 134: 373-381.
21	Harish S , Orejon D , Takata Y , et al . Thermal conductivity enhancement of lauric acid phase change nanocomposite with graphene nanoplatelets [J]. Applied Thermal Engineering, 2015, 80: 205-211.
22	Leng G , Qiao G , Xu G , et al . Erythritol-Vermiculite form-stable phase change materials for thermal energy storage [J]. Energy Procedia, 2017, 142: 3363-3368.
23	Lv P , Liu C , Rao Z . Experiment study on the thermal properties of paraffin/kaolin thermal energy storage form-stable phase change materials [J]. Applied Energy, 2016, 182: 475-487.
24	Lin C , Rao Z . Thermal conductivity enhancement of paraffin by adding boron nitride nanostructures: a molecular dynamics study [J]. Applied Thermal Engineering, 2017, 110: 1411-1419.
25	Babapoor A , Karimi G . Thermal properties measurement and heat storage analysis of paraffin nanoparticles composites phase change material: comparison and optimization [J]. Applied Thermal Engineering, 2015, 90: 945-951.
26	Xiao X , Zhang P , Li M . Preparation and thermal characterization of paraffin/metal foam composite phase change material [J]. Applied Energy, 2013, 112: 1357-1366.
27	Zheng H , Wang C , Liu Q , et al . Thermal performance of copper foam/paraffin composite phase change material [J]. Energy Conversion and Management, 2018, 157: 372-381.
28	Zhang H , Gao X , Chen C , et al . A capric-palmitic-stearic acid ternary eutectic mixture/expanded graphite composite phase change material for thermal energy storage [J]. Composites Part A: Applied Science and Manufacturing, 2016, 87: 138-145.
29	Tang Y , Su D , Huang X , et al . Synthesis and thermal properties of the MA/HDPE composites with nano-additives as form-stable PCM with improved thermal conductivity [J]. Applied Energy, 2016, 180: 116-129.
30	Li Y L , Li J H , Feng W W , et al . Design and preparation of the phase change materials paraffin/porous Al₂O₃@graphite foams with enhanced heat storage capacity and thermal conductivity [J]. ACS Sustainable Chemistry & Engineering, 2017, 5: 7594-7603.
31	Yang J , Qi G Q , Liu Y , et al . Hybrid graphene aerogels/phase change material composites: thermal conductivity, shape-stabilization and light-to-thermal energy storage [J]. Carbon, 2016, 100: 693-702.
32	Wang J , Huang X , Gao H , et al . Construction of CNT@Cr-MIL-101-NH₂ hybrid composite for shape-stabilized phase change materials with enhanced thermal conductivity [J]. Chemical Engineering Journal, 2018, 350: 164-172.
33	Liang W , Zhang G , Sun H , et al . Graphene-nickel/n -carboxylic acids composites as form-stable phase change materials for thermal energy storage [J]. Solar Energy Materials and Solar Cells, 2015, 132: 425-430.
34	Zhai T Y , Li T X , Wu S , et al . Preparation and thermal performance of form-stable expanded graphite/stearic acid composite phase change materials with high thermal conductivity [J]. Chinese Science Bulletin, 2017, 63(7): 674-683.
35	仵斯, 李廷贤, 闫霆, 等 . 高性能定形复合相变储能材料的制备及热性能[J]. 化工学报, 2015, 66 (12): 5127-5134.
	Wu S ， Li T X ， Yan T , et al . Preparation and thermal properties of high performance shape-stabilized phase change composites using stearic acid and expanded graphite [J]. CIESC Journal, 2015, 66 (12): 5127-5134.
36	向欢欢 . 三水合乙酸钠复合相变储热材料的制备与热物性研究 [D]. 广州: 广东工业大学, 2016.
	Xiang H H . Preparation and thermal performance research of sodium acetate trihydrate composite phase change heat storage material [D]. Guangzhou: Guangdong University of Technology, 2016.
37	秦盟盟 . 碳复合材料的微观结构调控及性能研究 [D]. 天津: 天津大学, 2017.
	Qin M M . Carbon-based composites with high thermal and mechanical properties by controlling their microstructures [D]. Tianjin: Tianjin University, 2017.
38	Wang T , Wang S , Wu W . Experimental study on effective thermal conductivity of microcapsules based phase change composites [J]. International Journal of Heat and Mass Transfer, 2017, 109: 930-937.

[1]	Wentao WU, Liangyong CHU, Lingjie ZHANG, Weimin TAN, Liming SHEN, Ningzhong BAO. High-efficient preparation of cardanol-based self-healing microcapsules [J]. CIESC Journal, 2023, 74(7): 3103-3115.
[2]	Zhilong WANG, Ye YANG, Zhenzhen ZHAO, Tao TIAN, Tong ZHAO, Yahui CUI. Influence of mixing time and sequence on the dispersion properties of the cathode slurry of lithium-ion battery [J]. CIESC Journal, 2023, 74(7): 3127-3138.
[3]	Zhen LI, Bo ZHANG, Liwei WANG. Development and properties of PEG-EG solid-solid phase change materials [J]. CIESC Journal, 2023, 74(6): 2680-2688.
[4]	Feng ZHU, Kailin CHEN, Xiaofeng HUANG, Yinzhu BAO, Wenbin LI, Jiaxin LIU, Weiqiang WU, Wangwei GAO. Performance study of KOH modified carbide slag for removal of carbonyl sulfide [J]. CIESC Journal, 2023, 74(6): 2668-2679.
[5]	Xueting ZHANG, Jijiang HU, Jing ZHAO, Bogeng LI. Preparation of high molecular weight polypropylene glycol in microchannel reactor [J]. CIESC Journal, 2023, 74(3): 1343-1351.
[6]	Zhiyuan JIN, Guorong SHAN, Pengju PAN. Preparation and heat and salt resistance of AM/AMPS/SSS terpolymer [J]. CIESC Journal, 2023, 74(2): 916-923.
[7]	Chengwei LI, Huayong LUO, Mingxuan ZHANG, Peng LIAO, Qian FANG, Hongwei RONG, Jingyin WANG. Microfludically-generated lanthanum hydroxide cross-linked chitosan microspheres for phosphate removal [J]. CIESC Journal, 2022, 73(9): 3929-3939.
[8]	Jianing LIU, Jiahao MA, Junying ZHANG, Jue CHENG. Construction and properties of sequential dual thermal curing thiol-acrylate-epoxy 3D network [J]. CIESC Journal, 2022, 73(9): 4173-4186.
[9]	Lei ZHONG, Xueqing QIU, Wenli ZHANG. Advances in lignin-derived carbon anodes for alkali metal ion batteries [J]. CIESC Journal, 2022, 73(8): 3369-3380.
[10]	Duanhui GAO, Weiqiang XIAO, Feng GAO, Qian XIA, Manqiu WANG, Xinbo LU, Xiaoli ZHAN, Qinghua ZHANG. Preparation and application of polyimide-based aerogels [J]. CIESC Journal, 2022, 73(7): 2757-2773.
[11]	Chaoyu SONG, Yaxuan XIONG, Jinhua ZHANG, Yuhe JIN, Chenhua YAO, Huixiang WANG, Yulong DING. Preparation and performance study of incinerated slag based shape-stable phase change composites [J]. CIESC Journal, 2022, 73(5): 2279-2287.
[12]	Hang GUO, Wenli HAN, Xiaoling DONG, Wencui LI. Adjusting carbonization process to optimize sodium storage performance of coal-based hard carbon anode [J]. CIESC Journal, 2022, 73(4): 1794-1806.
[13]	Chaoqun XU, Juan YU, Yimin FAN, Jifu WANG, Fuxiang CHU. Chemical modification of nanocellulose via atom transfer radical polymerization: strategy, applications and challenges [J]. CIESC Journal, 2022, 73(3): 1022-1043.
[14]	ZHOU Dongyi, XIAO Xianghua, XIAO Biao, LIU Yicai. Method of determining optimum mass ratio of fatty acids in composite phase change materials for thermal energy storage [J]. CIESC Journal, 2021, 72(S1): 560-566.
[15]	Kang YAN, Song YANG, Shoujun LIU, Chao YANG, Huiling FAN, Ju SHANGGUAN. In-situ preparation of ZnO-based activated carbon desulfurizer from low-rank coal [J]. CIESC Journal, 2021, 72(9): 4921-4930.