| 摘要: |
| 针对水作为冷藏保鲜领域常见的蓄冷剂存在相变时过冷度大、导热系数小的现象，研制了一种以水作为基液，添加纳米粒子及分散剂的复合相变材料，该材料配方质量比为水+0.7%纳米二氧化钛（TiO2）+1.0%十二烷基苯磺酸钠（SDBS），相变温度为0.216 ℃，相变潜热为353.1 kJ/kg。在水中加入纳米TiO2使水在相变过程的过冷度降低了5~6 ℃，且导热系数较基液提高了62.7%，从0.598 8 W/(m?K)升至0.974 5 W/(m?K)；同时添加分散剂SDBS，改善了水基纳米TiO2的沉降问题，提高了材料的稳定性，防止相分离。结合理论与实验，总结分析了纳米TiO2与分散剂SDBS不同质量比的水基纳米复合相变材料的热性能，确定纳米TiO2与分散剂SDBS在水中的最佳质量添加比为7∶10。通过最优例材料静置后的颜色观察和导热系数测试，表明纳米TiO2在水中具有良好的分散稳定性。 |
| 关键词: 复合相变材料 过冷度 导热系数 纳米材料 热性能 |
| DOI： |
| Received:March 03, 2017 |
| 基金项目:“十二五”农村领域国家科技支撑计划项目（2013BAD19B01）资助。 |
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| Preparation and Properties of Water-based Nano-TiO2 Composite Phase Change Material |
|
Ji Jun, Zeng Tao, Zhang Xuelai, Ren Yinglei, Chen Yufeng, Gao Yahan
|
| (Institute of Cool Thermal Energy Storage Technology, Shanghai Maritime University) |
| Abstract: |
| Water is a frequently used cool storage material in the field of refrigeration and food preservation. Because of the large supercooling degree during the phase change period and the low thermal conductivity of water, a composite water-based phase change material containing nanoparticles and a dispersing agent was developed. The mass ratio of the material is H2O+0.7% nano-TiO2+1.0% sodium dodecyl benzene sulfonate (SDBS). The phase change temperature of the composite phase change material is 0.216℃ and the latent heat is 353.1 kJ/kg. By adding nano-TiO2, the supercooling degree of water can be reduced by 5–6℃, while the thermal conductivity increases by 62.7%, from 0.5988 to 0.9745 W/(m?K). Moreover, adding the dispersing agent SDBS improves the sedimentation problems of water-based nano-TiO2, enhances the stability of the material, and prevents the phase separation phenomenon. Through theoretical and experimental analyses of the thermal properties of the composite phase change material with different nano-TiO2 and SDBS ratios, the optimal mass ratio is determined to be 7:10. The color and thermal conductivity of the optimal material after the installation indicate that nano-TiO2 has good dispersion stability in water. |
| Key words: composite phase change material supercooling degree thermal conductivity nanomaterial thermal property |
