日光温室用无机复合相变材料的制备及应用研究

为改善日光温室热环境，采用步冷曲线法和差示扫描量热法等实验方法研究制备了一种Na₂SO₄·10H₂O-Na₂HPO₄·12H₂O基复合相变材料，并将其改性后应用在温室模型中进行效果实验。实验结果表明：改性后此材料的最佳配比（质量分数）为21.37%Na₂SO₄·10H₂O+64.10%Na₂HPO₄·12H₂O+4.27%KCl+4.27%H₂O+4.27%Na₂SiO₃·9H₂O+0.86%石墨粉+0.86%羧甲基纤维素钠（CMC），其过冷度降至0.6 ℃、相变温度为25.1 ℃、相变潜热为143.7 J/g，经过200次冷热循环实验，相变材料仍能保持较好的相变性能；将其应用在温室模型中对比发现，该相变材料可减小温室内温度波动，晴天条件下相变材料可使室内最高温度降低1.6~3.1 ℃，使室内最低温度提高1.7~2.7 ℃，使土壤温度提高0.3~1.4 ℃，且连续晴天条件下相变材料的控温效果更加明显。

Study on preparation and application of inorganic composite phase change materials for solar greenhouse

In order to improve the thermal environment of solar greenhouse，a Na₂SO₄·10H₂O-Na₂HPO₄·12H₂O based composite phase change material was prepared by step cooling curve method and differential scanning calorimetry.After modification，it was applied to the greenhouse model for effect test.The experimental results showed that the optimum ratio（mass fraction） of the modified material was 21.37% Na₂SO₄·10H₂O+64.10% Na₂HPO₄·12H₂O+4.27% KCl+4.27% H₂O+4.27% Na₂SiO₃·9H₂O+0.86% graphite powder+0.86% CMC.The undercooling degree was reduced to 0.6 ℃，the phase change temperature was 25.1 ℃ and the phase change latent heat was 143.7 J/g.After 200 cold and hot cycle experiments，the phase change material could still maintain good phase change properties.The composite phase change material was applied to the greenhouse model.It was found that the phase change material could reduce the indoor temperature fluctuation in the greenhouse.In sunny days，the phase change material could reduce the indoor maximum temperature by 1.6~3.1 ℃，increase the indoor minimum temperature by 1.7~2.7 ℃ and increase the soil temperature by about 0.3~1.4 ℃.Meanwhile，the temperature control effect of phase change material was more obvious in continuous sunny days.