成核剂对八水氢氧化钡相变材料过冷度的影响
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摘要
八水氢氧化钡在相变过程中存在严重的相分离和过冷现象。采用步冷曲线法研究分析在冷水冷却封闭体系和室温冷却开放体系两种工况下石英、十二水磷酸氢二钠、硼砂和二水氯化钙4种成核剂对八水氢氧化钡相变材料的成核效果。实验表明:石英和十二水磷酸氢二钠随着添加量的增加,八水氢氧化钡的过冷度有增大的趋势。质量分数为3%或5%的硼砂和二水氯化钙在室温冷却开放体系工况下能够抑制八水氢氧化钡的过冷度,同时附加1%的明胶作为防相分层剂使用,八水氢氧化钡的过冷性能得到进一步改善,过冷度可降低至1℃以下,并且还可以有效地防止相分层。
Barium hydroxide octahydrate(Ba(OH)2·8H2O)has serious phase segregation and supercooling phenomena during phase change process.Nucleation of Ba(OH)2·8H2O doped 4nucleating agents such as quartz,Na2HPO4·12H2O,borax and CaCl2·2H2O was researched with gradually cooling method under closed system of water cooling and open system of room temperature cooling.The experiments showed that the supercooling degree of Ba(OH)2·8H2O doped the quartz and Na2HPO4·12H2O had an increasing tendency with the increasing of their adding amount.The additions of 3% or 5% borax and CaCl2·2H2O could reduce the supercooling degree of Ba(OH)2·8H2O under the open system of room temperature cooling.The supercooling performance of Ba(OH)2·8H2O can be further improved with 1% gelatin which was used as thickening agent,and the supercooling degree can be reduced below 1℃.It can effectively prevent phase segregation.
Barium hydroxide octahydrate(Ba(OH)2·8H2O)has serious phase segregation and supercooling phenomena during phase change process.Nucleation of Ba(OH)2·8H2O doped 4nucleating agents such as quartz,Na2HPO4·12H2O,borax and CaCl2·2H2O was researched with gradually cooling method under closed system of water cooling and open system of room temperature cooling.The experiments showed that the supercooling degree of Ba(OH)2·8H2O doped the quartz and Na2HPO4·12H2O had an increasing tendency with the increasing of their adding amount.The additions of 3% or 5% borax and CaCl2·2H2O could reduce the supercooling degree of Ba(OH)2·8H2O under the open system of room temperature cooling.The supercooling performance of Ba(OH)2·8H2O can be further improved with 1% gelatin which was used as thickening agent,and the supercooling degree can be reduced below 1℃.It can effectively prevent phase segregation.
引文
[1]张寅平,胡汉平,孔祥冬,等.相变贮能——理论和应用[M].合肥:中国科学技术大学出版社,1996,8-31.
[2]Naumann R,Emons H H.Results of thermal analysis for investigation of salt hydrates as latent heat-storage materials[J].Journal of Thermal Analysis,1989,35:1009-1031.
[3]曾翠华,张仁元.无机水合盐相变储热材料的过冷性研究[J].能源研究与信息,2005,21(1):44-49.
[4]沈卫东,曾丹苓.车用潜热贮热器相变贮热材料Ba(OH)2·8H2O的成核[J].工程热物理学报,1996,17:5-8.
[5]李金田,茅靳丰,李伟华,等.三水醋酸钠的过冷机理与实验研究[J].制冷学报,2009,30(5):32-35.
[6]李晶.相变蓄热材料及其相变特性的研究[D].北京:北京工业大学,2005.
[7]石海民,梁德青,李栋梁,等.CH3COONa·3H2O相变蓄热性能研究[J].制冷学报,2009,30(2):8-11.
[8]丁益民,阎立诚,薛俊慧.水合盐储热材料的成核作用[J].化学物理学报,1996,9(1):83-86.
[9]王智平,郭长华,王克振,等.相变材料三水醋酸钠储热性能实验研究[J].化学工程,2011,39(5):27-30.
[10]李晶,刘中良,马重芳.改善三水醋酸钠固液相变性能的实验研究[J].工程热物理学报,2006,27(5):817-819.
[2]Naumann R,Emons H H.Results of thermal analysis for investigation of salt hydrates as latent heat-storage materials[J].Journal of Thermal Analysis,1989,35:1009-1031.
[3]曾翠华,张仁元.无机水合盐相变储热材料的过冷性研究[J].能源研究与信息,2005,21(1):44-49.
[4]沈卫东,曾丹苓.车用潜热贮热器相变贮热材料Ba(OH)2·8H2O的成核[J].工程热物理学报,1996,17:5-8.
[5]李金田,茅靳丰,李伟华,等.三水醋酸钠的过冷机理与实验研究[J].制冷学报,2009,30(5):32-35.
[6]李晶.相变蓄热材料及其相变特性的研究[D].北京:北京工业大学,2005.
[7]石海民,梁德青,李栋梁,等.CH3COONa·3H2O相变蓄热性能研究[J].制冷学报,2009,30(2):8-11.
[8]丁益民,阎立诚,薛俊慧.水合盐储热材料的成核作用[J].化学物理学报,1996,9(1):83-86.
[9]王智平,郭长华,王克振,等.相变材料三水醋酸钠储热性能实验研究[J].化学工程,2011,39(5):27-30.
[10]李晶,刘中良,马重芳.改善三水醋酸钠固液相变性能的实验研究[J].工程热物理学报,2006,27(5):817-819.