摘要
【目的】针对热电联产系统在峰值负荷或极端环境下应急冷却需求激增、传统水蓄冷技术储能密度低以及有机相变材料热导率不足等问题,本研究旨在开发一种兼具适宜相变温度、高潜热与高热导率的复合相变材料(composite phase change material,CPCM),以提升系统热管理效率与能量利用率。【方法】本文以正辛酸(octanoic acid,OA)与月桂酸(lauric acid,LA)为基材,基于Schrader方程理论计算二元共晶配比,结合步冷曲线法、差示扫描量热法及熔融-凝固循环实验,筛选适用于5~8℃温域的共晶基液;进一步利用膨胀石墨(expanded graphite,EG)的多孔结构吸附特性制备OA-LA/EG复合材料,系统分析其相变温度、潜热、热导率及循环稳定性。【结果】研究表明,OA-LA质量比80:20的共晶基液相变温度为5.4℃,潜热为158.8 J/g;添加12 wt%EG后,复合材料的相变温度稳定于5.2℃,潜热为145.8 J/g,热导率提升至2.23 W/(m·K),较纯OA-LA提高约6倍,并显著抑制了过冷现象(过冷度≤0.2℃)。经1000次循环后,潜热衰减率仅为13.2%,表现出优异的循环稳定性。【结论】OALA/EG复合材料凭借其适配的相变温度、高储能密度与快速热响应特性,为热电联产系统提供了高效的应急冷源解决方案,对提升系统运行稳定性与能源综合利用效率具有重要应用价值。
[Objective]In response to the surge of emergency cooling demand of combined heat and power(CHP)system under peak load or extreme environment,the low energy storage density of traditional water storage technology,and the insufficient thermal conductivity of organic phase change materials,the present study is aimed at developing a composite phase change material(CPCM)with suitable phase change temperature,high latent heat,and high thermal conductivity in order to enhance the thermal management efficiency and energy utilization of the system.[Methods]Using octanoic acid(OA)and lauric acid(LA)as substrates,we calculated the binary eutectic ratios based on Schrader's equation theory,and screened the eutectic matrix suitable for the temperature range of 5~8℃by combining the stepcooling curve method,the differential scanning calorimetry(DSC)method,and the melting-solidification cycle experiments;and we further used the adsorption property of expanded graphite(EG)to prepare the OA-LA/EG composites,and systematically analyzed their phase change temperature and thermal conductivity.Further,the porous structure of expanded graphite(EG)was used to prepare OA-LA/EG composites,and the phase transition temperature,latent heat,thermal conductivity and cycling stability were systematically analyzed.[Results]The results show that the phase transition temperature of the eutectic matrix with 80:20 OA-LA mass ratio is 5.4℃,and the latent heat is 158.8 J/g.With the addition of 12 wt%EG,the phase transition temperature of the composites is stabilized at 5.2℃,and the latent heat is 145.8 J/g,and the thermal conductivity is increased to 2.23 W/(m·K),which is 6 times higher than that of the pure OA-LA,and the supercooling phenomenon has been suppressed.(supercooling degree≤0.2℃).After 1000 cycles,the latent heat decay rate is only 13.2%,showing excellent cycling stability.[Conclusion]OA-LA/EG composites provide an efficient emergency cooling solution for cogeneration systems by virtue of their adaptable phase change temperature,high energy storage density and fast thermal response,which is of great value for improving the stability of the system and the efficiency of the comprehensive use of energy.
作者
倪明龙
乐小龙
陈振乾
王磊
施娟
刘明涛
盛帮明
李晓琪
李志远
NI Minglong;YUE Xiaolong;CHEN Zhenqian;WANG Lei;SHI Juan;LIU Mingtao;SHENG Bangming;LI Xiaoqi;LI Zhiyuan(China Energy Engineering Group Jiangsu Power Design Institute Co.,Ltd.,Nanjing 211102,Jiangsu China;School of Energy and Environment,Southeast University,Nanjing 211189,Jiangsu China)
出处
《电力科技与环保》
2025年第3期477-487,共11页
Electric Power Technology and Environmental Protection
基金
中国电力工程顾问集团有限公司科技项目(DG2-A02-2022)。
关键词
有机脂肪酸
膨胀石墨
相变温度
导热率
复合材料
organic fatty acid
expanded graphite
phase change temperature
thermal conductivity
composite material
