Direct Solar Thermal Energy Storage Using a Semitransparent Phase Change Material

使用半透明相变材料的直接太阳能热存储

• 批准号: 01550729
• 负责人: NISHIMURA Makoto
• 金额: $ 1.28万
• 依托单位: Gifu University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1989
• 资助国家: 日本
• 起止时间: 1989 至 1990
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-01550729/
• 关键词: Heat storage; Latent heat storage; Phase change material; Solar thermal energy; Volume heat trap; 輻射伝熱; 温度分布

The latent heat storage of a volume heat trap (VHT) type was proposed as a new passive system of solar thermal energy storage, in which a plane layer of a semitransparent phase change material (PCM) is directly heated and melted by the sun. The performance was investigated in the indoor and the outdoor experiments and analyzed theoretically. Those of the latent heat storage of surface heat trap (SHT) type and the sensible heat storage of VHT type were examined in parallel. Paraffin wax was used as a PCM and the time changes of temperature distributions in the collector during heat storage weremeasured. The tilt angle of the collector and the thickness of PCM were varied. In the theoretical analysis, the basic equations were derived by assuming the two-dimensional fluid flow and heat transfer and by applying the concept of overall specific heat, and were solved numerically. The effects of the tilt angle and the thickness of PCM on the time changes of temperature distribution and heat storage efficiency were discussed. As a result, the following conclusions were obtained.1) The calculated results reasonably expressed the tendencies of the experimental data so that the present theoretical analysis was considered to be valid.2) The latent heat storage of VHT type was superior in performance to the latent heat storage of SHT type and the sensible heat storage of VHT type.3) In the latent heat storage of VHT type, the internal heating and the heat and fluid flow by natural convection affected the characteristics of heat storage.4) In the outdoor experiments, the most suitable tilt angle was found to be solar incidence angle at the time of culmination.

提出了体积热阱（VHT）型潜热蓄能作为一种新型的被动式太阳能热能蓄能系统，该系统将半透明相变材料（PCM）的平面层直接由太阳加热和熔化。通过室内和室外实验对其性能进行了研究，并进行了理论分析。并对地表热阱（SHT）型潜热蓄热和VHT型感热蓄热进行了对比研究。采用石蜡作为PCM，测量了蓄热过程中集热器内温度分布的时间变化。改变了集电极的倾角和PCM的厚度。在理论分析中，通过假设二维流体流动和换热，应用总比热的概念推导了基本方程，并进行了数值求解。讨论了倾斜角度和厚度对温度分布和蓄热效率随时间变化的影响。结果得出以下结论：1)计算结果合理地表达了实验数据的趋势，认为本文的理论分析是有效的。2) VHT型潜热蓄热性能优于SHT型潜热蓄热和VHT型感热蓄热。3)在VHT型潜热蓄热中，内部加热和自然对流的热量和流体流动影响了蓄热特性。4)在室外实验中，发现最适宜的倾角为日全食时的太阳入射角。

项目成果

Makoto Nishimura, Yoshiyuki Bando, Hiroyuki Sota, Masahito Hayashi and Mitsutoshi Minatani: "Effect of Number and Setting Position of Transparent Partitioning Films on Collection Characteristics of "Volume Heat Trap" Solar Collector" Kagaku Kogaku Ronbuns

Makoto Nishimura、Yoshiyuki Bando、Hiroyuki Sota、Masahito Hayashi 和 Mitsutoshi Minatani：“透明隔断膜的数量和设置位置对“体积热阱”太阳能集热器集热特性的影响” Kagaku Kogaku Ronbuns

西村 誠,坂東 芳行,曽田 裕行,林 雅人,南谷 充利: "体積受熱型ソ-ラコレクタの集熱特性に及ぼす透過性仕切膜の枚数および設置位置の影響" 化学工学論文集. 第16巻. 1038-1044 (1990)

Makoto Nishimura、Yoshiyuki Bando、Hiroyuki Soda、Masato Hayashi、Mitsutoshi Minamitani：“渗透隔断膜的数量和安装位置对体积受热太阳能集热器的集热特性的影响”化学工程杂志第 16 卷，第 1038 卷。 -1044 (1990)