Na_2SO_4·10H_2O复合相变储冷体系的热力学性质

Thermodynamic Properties of Sodium Sulfate-Based Complex Phase-Change Cool Storage System

目的 研究制备相变温度在 5～ 1 0℃之间的新型空调储冷材料 .方法 测定以Na2 SO4· 1 0 H2 O为主要成分的低共熔混合体系的相变温度随组成变化的关系 ,确定适宜配方 .研究抑制过冷和相分层现象的方法 .结果 由质量分数为 80 %的 Na2 SO4· 1 0 H2 O、2 %～ 8%的 KCl、5 %～ 1 0 %NH4Cl和 1 %～ 5 %( NH4) 2 SO4组成的低共熔水合盐体系的相变温度降至 9～ 1 0℃ .结论 加入无机盐 KCl,NH4Cl,( NH4) 2 SO4或 Na Cl可降低 Na2 SO4.1 0 H2 O的相变温度 .加入成核剂和增稠剂是解决过冷和相分层的有效方法 .

Aim To investigate and prepare a new material for cool storage of air conditioner in temperature range of 5～10 ℃. Methods The variation of phase transition temperature with the composition of the cool storage system in which Na 2SO 4·10H 2O was selected as the main component was determined, and suitable formulas were defined. Means for preventing supercooling and segregation were studied. Results An eutectic salt hydrate composition comprising 80% of Na 2SO 4·10H 2O,2%～8% of KCl, 5%～10%NH 4Cl and 1%～5%(NH 4) 2SO 4 has a melting point of 9～10 ℃. Conclusion Na 2SO 4·10H 2O's transition temperature was reduced by adding salts——KCl, NH 4Cl, (NH 4) 2SO 4 or NaCl. Adding a nucleating agent and a thickening agent can inhibit supercooling and eliminate segregation.