基于四氢呋喃的相变蓄冷材料的制备及其性能研究

Preparation and Properties of Tetrahydrofuran-Based Phase Change Cold Storage Materials

摘要:

为满足北部湾海洋运输果蔬冷链保鲜的特定需求，研发一种适宜的相变蓄冷材料显得尤为重要。由于四氢呋喃（THF）相较于其他水合物所需严苛的低温高压生成条件不同，其水合物能够在常压环境下生成，因此被视为一种适宜的运输蓄冷介质。以浓度99%的THF（10.446 g）和去离子水（30 g）作为核心基液，以氯化钠（10 g）作为温度调节剂，选用3种不同质量分数（3%、6%、9%）的聚乙烯醇作为增稠剂，研制出了一种高效且性能稳定的相变蓄冷材料(PCM)。利用差示扫描量热法（DSC）探究了THF与氯化钠（NaCl）混合水合物的蓄冷性能，同时进行了不同质量分数增稠剂的对比实验。结果表明：浓度为99%的THF和去离子水作为核心基液，构成了PCM材料的主体框架，保障其基本热物理特性的稳定；引入的氯化钠作为温度调节剂，通过调控其比例可优化PCM材料的相变温度范围，以更好地满足特定应用场景的需求；聚乙烯醇作为增稠剂，不仅使PCM相变温度得到改善，而且还增强了PCM的稳定性、有效地抑制了相分离，确保了材料在固液相变过程中的稳定，从而提高了PCM蓄冷性能，当聚乙烯醇质量分数为6%时有助于维持材料在相变过程中的均匀性。为解决材料过冷度问题，引入了质量分数为1.4%的壬酸成核剂，并进行了梯度实验。结果表明，壬酸的加入能显著降低相变材料的过冷度（近乎降至零），从而使PCM材料表现出理想的相变特性，相变温度（Onset温度）稳定位于6.3—8.0 ℃的区间内，适用于低温储能领域。同时，PCM材料的相变潜热值为115 J?g^-1左右，表明其具有较高的能量存储密度，能够有效地吸收和释放热量。通过合理的药剂配比与优化，制备出了一种性能较好、过冷度极低的THF基共晶体相变材料，为蓄冷技术的发展提供了有力的支持。

Abstract:

Aiming at the application scenario of fruit and vegetable preservation in marine cold chain logistics within the Beibu Gulf， it is particularly important to synthesize a suitable phase change cold storage material. A phase change material （PCM） with high efficiency and stable performance was developed. Differential scanning calorimetry （DSC） was used to explore the cold storage performance of tetrahydrofuran （THF） and sodium chloride mixed hydrate， and a phase change material with high efficiency and stable performance was developed. The PCM was synthesized using a core base liquid containing 10.446 g of 99% THF and 30 g deionized water. Sodium chloride （10 g） was integrated as a temperature regulator to adjust the phase transition range for practical refrigeration requirements. The PCM was synthesized using a core base liquid containing 10.446 g 99% tetrahydrofuran （THF） and 30 g deionized water. In order to optimize the PCM phase change temperature range， sodium chloride （10 g） was integrated as a temperature regulator for practical refrigeration requirements. To mitigate phase separation， three different mass fractions （3%， 6%， 9%） of polyvinyl alcohol were selected for comparative experiments， and it was found that 6% polyvinyl alcohol optimally enhanced material homogeneity during the phase transition process. Additionally， nonanoic acid with a mass fraction of 1.4% was introduced as a nucleating agent through layer experiments. The addition of nonanoic acid significantly reduces the supercooling degree of the phase change material， almost reducing it to zero. The PCM exhibits ideal phase transition characteristics with stable phase transition onset temperature between 6.3—8.0 ℃， which is suitable for low temperature energy storage. The phase change enthalpy of the optimized PCM is about 115 J·g^-1， indicating high thermal energy storage capacity. This study has prepared a tetrahydrofuran-based eutectic phase change material with good performance and very low undercooling through reasonable drug ratio and optimization， providing strong support for the development of cold storage technology.