正十八烷/OBC/EG复合定型相变材料制备及热物性

doi:10.11949/0438-1157.20201504

摘要/Abstract

摘要：

针对正十八烷相变易泄漏的问题，采用烯烃嵌段共聚物（olefin block copolymer，OBC）作为封装结构，制备复合定型相变材料。并通过添加膨胀石墨（expanded graphite，EG），改善其热导率低的问题。研究结果表明，当OBC的质量分数为20%时，复合相变材料未发现明显泄漏，定型效果较好，此时复合相变材料的相变焓为166.87 J/g，相较纯十八烷（227.40 J/g）下降26.62%。针对添加有不同质量分数EG的复合相变材料，其热导率随EG含量的增加而增大。其中当EG质量分数为5%时，复合相变材料热导率为4.179 W/(m?K)，较纯相变材料热导率[0.24 W/(m?K)提高了约16倍，即EG能够有效提高复合相变材料的导热性能。此外，5%含量下的复合相变材料相变焓约为149.54 J/g，且在经历50次循环后，相变温度和相变焓均未有明显变化，即制备的复合相变材料具有较好的热稳定性。因此，该复合相变材料在建筑节能方面具有应用潜力。

关键词: 正十八烷, 相变, 混合, 烯烃嵌段共聚物, 热传导

Abstract:

Aiming at the problem that leakage always happen in the phase change process of octadecane, olefin block copolymer (OBC) is used as the packaging structure to prepare composite stereotyped phase change materials (PCMs). Meanwhile, the low thermal conductivity of octadecane is improved by adding expanded graphite (EG). The results show that when the mass fraction of OBC is 10%, the leakage will happen in the phase change process. However, leakage has not been observed when the mass fraction of OBC is equal to or higher than 20%. When the mass fraction of OBC is 20%, the phase change enthalpy of the composite PCM is 166.87 J/g, and lower than that of pure ocadecane (227.40 J/g) by 26.62%. The thermal conductivity of composite phase change materials with different mass fraction of EG increases with the increase of the content of EG. When the mass fraction of EG is 5%, the thermal conductivity of the composite PCM is 4.179 W/(m?K), which is about 16 times higher than that of the pure PCM [0.24 W/(m?K)], indicating that EG could effectively improve the thermal conductivity of the composite PCM. In addition, the phase change enthalpy of composite PCM with 5% EG was about 149.54 J/g, and there was no significant change in phase change temperature and enthalpy after 50 cycles, indicating that the thermal stability of the composite PCM is great. Therefore, the composite phase change material has the utilization potentiality in building energy conservation.

Key words: octadecane, phase change, mixtures, OBC, heat conduction

中图分类号:

TK 02

何起帆, 吴闽强, 李廷贤, 王如竹. 正十八烷/OBC/EG复合定型相变材料制备及热物性[J]. 化工学报, 2021, 72(S1): 539-545.

HE Qifan, WU Minqiang, LI Tingxian, WANG Ruzhu. Preparation and thermophysical properties of octadecane/ OBC/ EG composite shaped phase change material[J]. CIESC Journal, 2021, 72(S1): 539-545.

图/表 10

图1 复合相变材料定型效果

Fig.1 Pictures of composite PCM shape stability effect

图2 正十八烷/OBC复合相变材料DSC谱图

Fig.2 DSC thermogram of octaecane/OBC composite PCM

表1 正十八烷/OBC复合相变材料熔化过程的相变温度及相变焓

Table1 Phase change temperature and enthalpy of octaecane/OBC composite PCM in melting process

材料	起始温度T_ms/℃	峰值T_mp/℃	终止温度T_me/℃	相变焓H_m/(J/g)
纯正十八烷	27.97	30.08	31.06	227.40
10% OBC/正十八烷	23.64	27.03	30.45	193.62
20% OBC/正十八烷	22.72	26.98	32.56	166.87
30% OBC/正十八烷	21.92	26.96	29.26	136.37

表2 正十八烷/OBC复合相变材料凝固过程的相变温度及相变焓

Table2 Phase change temperature and enthalpy of octaecane/OBC composite PCM during solidification

材料	起始温度T_ms/℃	峰值T_mp/℃	终止温度T_me/℃	相变焓H_m/(J/g)
纯正十八烷	24.06	22.00	19.79	230.40
10% OBC/正十八烷	21.74	20.26	18.27	191.68
20% OBC/正十八烷	22.75	19.23	14.15	161.99
30% OBC/正十八烷	22.14	18.00	15.51	138.43

图3 正十八烷/OBC/EG复合相变材料DSC谱图

Fig.3 DSC thermogram of octaecane/OBC/EG composite PCM

图4 正十八烷/OBC/EG复合相变材料熔化过程相变焓及温度

Fig.4 Phase change enthalpy and temperature of octaecane/OBC/EG composite PCM in melting process

图5 正十八烷/20% OBC/5% EG复合相变材料50次循环DSC图谱

Fig.5 DSC thermogram of octaecane/ 20% OBC/ 5% EG composite PCM after 50 times circle

图6 正十八烷/OBC/EG复合相变材料热导率

Fig.6 Thermal conductivity of octaecane/ OBC/ EG composite PCM

图7 正十八烷/OBC/EG复合相变材料升温曲线

Fig.7 Heating curves of octaecane/ OBC/ EG composite PCM

图8 正十八烷/OBC/EG复合相变材料升温过程实时温度分布

Fig.8 Temperature distribution of octaecane/ OBC/ EG composite PCM in heating process

参考文献 33

1	Moss R H, Edmonds J A, Hibbard K A, et al. The next generation of scenarios for climate change research and assessment [J]. Nature, 2010, 463(7282): 747-756.
2	Lippelt J, Sindram M. Global energy consumption [J]. CESifo Forum, 2011, 12: 80-82.
3	Ji H X, Sellan D P, Pettes M T, et al. Enhanced thermal conductivity of phase change materials with ultrathin-graphite foams for thermal energy storage [J]. Energy Environ. Sci., 2014, 7(3): 1185-1192.
4	Nomura T, Okinaka N, Akiyama T. Waste heat transportation system, using phase change material (PCM) from steelworks to chemical plant [J]. Resources, Conservation and Recycling, 2010, 54(11): 1000-1006.
5	Song M J, Niu F X, Mao N, et al. Review on building energy performance improvement using phase change materials [J]. Energy and Buildings, 2018, 158: 776-793.
6	Gur I, Sawyer K, Prasher R. Engineering. Searching for a better thermal battery [J]. Science, 2012, 335(6075): 1454-1455.
7	Han G G D, Li H S, Grossman J C. Optically-controlled long-term storage and release of thermal energy in phase-change materials [J]. Nature Communications, 2017, 8: 1446.
8	Kenisarin M, Mahkamov K. Solar energy storage using phase change materials [J]. Renewable and Sustainable Energy Reviews, 2007, 11(9): 1913-1965.
9	Xiao X, Zhang P, Li M. Experimental and numerical study of heat transfer performance of nitrate/expanded graphite composite PCM for solar energy storage [J]. Energy Conversion and Management, 2015, 105: 272-284.
10	Huang M J, Eames P C, McCormack S, et al. Microencapsulated phase change slurries for thermal energy storage in a residential solar energy system [J]. Renewable Energy, 2011, 36(11): 2932-2939.
11	Khan Z, Khan Z, Ghafoor A. A review of performance enhancement of PCM based latent heat storage system within the context of materials, thermal stability and compatibility [J]. Energy Conversion and Management, 2016, 115: 132-158.
12	Soares N, Costa J J, Gaspar A R, et al. Review of passive PCM latent heat thermal energy storage systems towards buildings' energy efficiency [J]. Energy and Buildings, 2013, 59: 82-103.
13	王鑫, 方建华, 刘坪, 等. 相变材料的研究进展[J]. 功能材料, 2019, 50(2): 2070-2075.
	Wang X, Fang J H, Liu P, et al. Research progress of phase change materials [J]. Journal of Functional Materials, 2019, 50(2): 2070-2075.
14	Tao P, Shang W, Song C Y, et al. Bioinspired engineering of thermal materials [J]. Advanced Materials, 2015, 27(3): 428-463.
15	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.
16	Aftab W, Mahmood A, Guo W H, et al. Polyurethane-based flexible and conductive phase change composites for energy conversion and storage [J]. Energy Storage Materials, 2019, 20: 401-409.
17	Yang J, Zhang E W, Li X F, et al. Cellulose/graphene aerogel supported phase change composites with high thermal conductivity and good shape stability for thermal energy storage [J]. Carbon, 2016, 98: 50-57.
18	Li G Y, Zhang X T, Wang J, et al. From anisotropic graphene aerogels to electron- and photo-driven phase change composites [J]. Journal of Materials Chemistry A, 2016, 4(43): 17042-17049.
19	Kholmanov I, Kim J, Ou E, et al. Continuous carbon nanotube-ultrathin graphite hybrid foams for increased thermal conductivity and suppressed subcooling in composite phase change materials [J]. ACS Nano, 2015, 9(12): 11699-11707.
20	Ye S B, Zhang Q L, Hu D D, et al. Core–shell-like structured graphene aerogel encapsulating paraffin: shape-stable phase change material for thermal energy storage [J]. Journal of Materials Chemistry A, 2015, 3(7): 4018-4025.
21	Wu S, Li T X, Wu M Q, et al. Highly thermally conductive and flexible phase change composites enabled by polymer/graphite nanoplatelet-based dual networks for efficient thermal management [J]. Journal of Materials Chemistry A, 2020, 8(38): 20011-20020.
22	Giro-Paloma J, Martínez M, Cabeza L F, et al. Types, methods, techniques, and applications for microencapsulated phase change materials (MPCM): a review [J]. Renewable and Sustainable Energy Reviews, 2016, 53: 1059-1075.
23	de Cortazar M G, Rodríguez R. Thermal storage nanocapsules by miniemulsion polymerization [J]. Journal of Applied Polymer Science, 2013, 127(6): 5059-5064.
24	Zhang J, Wang S S, Zhang S D, et al. In situ synthesis and phase change properties of Na₂SO₄·10H₂O@SiO₂ solid nanobowls toward smart heat storage [J]. The Journal of Physical Chemistry C, 2011, 115(41): 20061-20066.
25	Fang Y T, Kuang S Y, Gao X N, et al. Preparation and characterization of novel nanoencapsulated phase change materials [J]. Energy Conversion and Management, 2008, 49(12): 3704-3707.
26	蔡迪, 李静, 焦乃勋. 纳米石墨烯片-正十八烷复合相变材料制备及热物性研究[J]. 物理学报, 2019, 68(10): 18-26.
	Cai D, Li J, Jiao N X. Preparation and thermophysical properties of graphene nanoplatelets-octadecane phase change composite materials [J]. Acta Physica Sinica, 2019, 68(10): 18-26.
27	李琳, 李东旭, 刘洋, 等. 月桂酸-肉豆蔻酸/膨胀石墨封装复合相变储能材料的制备及表征[J]. 太阳能学报, 2016, 37(10): 2627-2632.
	Li L, Li D X, Liu Y, et al. Preparation and characterization of lauric acid-myristic acid/expanded graphite composite encapsulated phase change energy storage material [J]. Acta Energiae Solaris Sinica, 2016, 37(10): 2627-2632.
28	刘菁伟, 杨文彬, 田本强, 等. 石蜡/高密度聚乙烯/膨胀石墨导热增强型复合相变材料热导率的影响因素[J]. 高分子材料科学与工程, 2015, 31(5): 83-86, 92.
	Liu J W, Yang W B, Tian B Q, et al. Thermal conductivity of paraffin/HDPE/expanded graphite phase change composite [J]. Polymer Materials Science & Engineering, 2015, 31(5): 83-86, 92.
29	Shi J M, Huang X Y, Guo H C, et al. Experimental investigation and numerical validation on the energy-saving performance of a passive phase change material floor for a real scale building [J]. ES Energy & Environment, 2020, 8: 21-28.
30	Kuznik F, Virgone J. Experimental assessment of a phase change material for wall building use [J]. Applied Energy, 2009, 86(10): 2038-2046.
31	Kuznik F, Virgone J, Johannes K. In-situ study of thermal comfort enhancement in a renovated building equipped with phase change material wallboard [J]. Renewable Energy, 2011, 36(5): 1458-1462.
32	Mi X M, Liu R, Cui H Z, et al. Energy and economic analysis of building integrated with PCM in different cities of China [J]. Applied Energy, 2016, 175: 324-336.
33	Butala V, Stritih U. Experimental investigation of PCM cold storage [J]. Energy and Buildings, 2009, 41(3): 354-359.

[1]	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.
[2]	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.
[3]	谈莹莹, 刘晓庆, 王林, 黄鲤生, 李修真, 王占伟. R1150/R600a自复叠制冷循环开机动态特性实验研究[J]. 化工学报, 2023, 74(S1): 213-222.
[4]	江河, 袁俊飞, 王林, 邢谷雨. 均流腔结构对微细通道内相变流动特性影响的实验研究[J]. 化工学报, 2023, 74(S1): 235-244.
[5]	吴延鹏, 刘乾隆, 田东民, 陈凤君. 相变材料与热管耦合的电子器件热管理研究进展[J]. 化工学报, 2023, 74(S1): 25-31.
[6]	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.
[7]	刘远超, 关斌, 钟建斌, 徐一帆, 蒋旭浩, 李耑. 单层XSe₂（X=Zr/Hf）的热电输运特性研究[J]. 化工学报, 2023, 74(9): 3968-3978.
[8]	程小松, 殷勇高, 车春文. 不同工质在溶液除湿真空再生系统中的性能对比[J]. 化工学报, 2023, 74(8): 3494-3501.
[9]	汪尔奇, 彭书舟, 杨震, 段远源. 含HFO混合体系气液相平衡的理论模型评价[J]. 化工学报, 2023, 74(8): 3216-3225.
[10]	史昊鹏, 钟达文, 廉学新, 张君峰. 朝下多尺度沟槽翅片结构表面沸腾换热实验研究[J]. 化工学报, 2023, 74(7): 2880-2888.
[11]	黄可欣, 李彤, 李桉琦, 林梅. 加装旋转叶轮T型通道流场的模态分解[J]. 化工学报, 2023, 74(7): 2848-2857.
[12]	史方哲, 甘云华. 超薄热管启动特性和传热性能数值模拟[J]. 化工学报, 2023, 74(7): 2814-2823.
[13]	邢美波, 张中天, 景栋梁, 张洪发. 磁调控水基碳纳米管协同多孔材料强化相变储/释能特性[J]. 化工学报, 2023, 74(7): 3093-3102.
[14]	张贲, 王松柏, 魏子亚, 郝婷婷, 马学虎, 温荣福. 超亲水多孔金属结构驱动的毛细液膜冷凝及传热强化[J]. 化工学报, 2023, 74(7): 2824-2835.
[15]	张艳梅, 袁涛, 李江, 刘亚洁, 孙占学. 高效SRB混合菌群构建及其在酸胁迫条件下的性能研究[J]. 化工学报, 2023, 74(6): 2599-2610.