摘要
定形复合相变材料(SCPCM)具有高能量存储密度和高热稳定性的优点,然而内部的相变介质在持续吸热发生相变时,熔融态的相变介质容易泄漏,造成材料变形和腐蚀的问题。利用氢氧化钠(NaOH)对粉煤灰(FA)进行简单的改性处理,以改性粉煤灰(mFA)为陶瓷基体材料,Al-12Si合金粉为相变介质,通过混合烧结法制备高温定形复合相变材料(HTSCPCM)。采用扫描电子显微镜(SEM)、X射线能谱分析仪(EDS)、X射线衍射仪(XRD)、全自动比表面及孔隙度分析仪(BET)、同步热分析仪(TG-DSC)和导热系数仪(Hot Disk)等进行测试与表征。结果表明,碱改性制备的mFA表面呈丰富的多级结构,比表面积由3.82 cm^(2)/g提升到40.86 cm^(2)/g,孔容由0.008 cm^(3)/g提升到0.085 cm^(3)/g。混合烧结法制备的Al-12Si/mFA HTSCPCM成形效果良好,Al-12Si合金粉与改性粉煤灰陶瓷基体结合紧密,基体对Al-12Si合金粉的最大负载率为65%,相变潜热为97.76 J/g,热导率为15.10 W/(m·K)。在经过100次冷热循环后,形态依旧完整,无泄漏情况发生,相变潜热变为91.32 J/g,循环前后仅降低6.6%。因此,本工作制备的Al-12Si/mFA HTSCPCM具有相变温度适宜、热导率高、储热密度高和易加工等优点,有望在高温储热领域被应用。
Shaped composite phase change materials(SCPCMs) have the advantages of high energy storage density and high thermal stability.However,the internal phase change medium in the molten state is prone to leakage as it continuously absorbs heat during phase changes,resulting in material deformation and corrosion.To overcome this,a high temperatureshaped composite phase change material(HTSCPCM) was prepared using sodium hydroxidemodified fly ash(mFA) as a ceramic matrix and Al-12Si alloy powder as a phase change medium using a hybrid sintering method.Testing and characterization were conducted using scanning electron microscopy,energy-dispersive X-ray spectroscopy,X-ray diffraction,fully automated specific surface and porosity analyses,thermogravimetry-differential scanning calorimetry,and thermal conductivity.The results showed that sodium hydroxide-modification of FA resulted in multilevel surfaces and enhanced specific surface area(3.82 to 40.86 cm^(2)/g)and pore volume(0.008 to 0.085 cm^(3)/g).The Al-12Si alloy was shown to be securely bonded to the mFA ceramic matrix.The maximum loading of the matrix to the Al-12Si alloy was 65%,the latent heat of phase transition was 97.76 J/g,and the thermal conductivity was 15.10 W/(m·K).After 100 thermal cycles,the morphology of the AI-12Si/mFA HTSCPCM was unchanged,and no leakage was observed.The latent heat of the phase change was 91.32 J/g,and it decreased by only 6.6% before and after each cycle.The AI-12Si/mFA HTSCPCM prepared in this work has the advantages of a suitable phase transition temperature,high thermal conductivity,high heat storage density,and ease of processing.The results of this study indicate that this AI-12Si/mFA HTSCPCM can be used in the field of high-temperature heat storage.
作者
肖天烈
郁青春
刘治平
阴树标
XIAO Tianlie;YU Qingchun;LIU Zhiping;YIN Shubiao(Faculty of Metallurgical and Engineering,Kunming University of Science and Technology,Kunming 650093,Yunnan,China;National Engineering Research Centre of Vacuum Metallurgy,Kunming University of Science and Technology,Kunming 650093,Yunnan,China;Minegeology and Environment Academician and Expert Workstation,Ordos Institute of Technology,Ordos 017000,Inner Mongolia,China)
出处
《储能科学与技术》
CAS
CSCD
北大核心
2023年第12期3699-3708,共10页
Energy Storage Science and Technology
基金
粉煤灰改性真空烧结制备储能材料的基础研究(20230ITYSZJGZZ-001)。
关键词
粉煤灰
相变材料
热能储存
铝硅合金
fly ash
phase change material
thermal energy storage
Al-Si alloy