【作者】 于静；

【导师】 张晓冬；

【作者基本信息】 大连理工大学 ， 安全技术及工程， 2012， 硕士

【摘要】 在能源紧张和环境问题突出的今天,利用太阳能和工业废热的吸收式制冷技术方兴未艾,而目前工业上广泛应用的吸收式制冷工质对氨-水溶液和溴化锂-水溶液的先天缺陷(冷剂氨有毒、易爆、与吸收剂水的沸点差较小；溴化锂-水溶液易结晶、对设备腐蚀、无法获得0℃以下的低温)制约着制冷技术的发展,所以寻找适应范围广,效率高的新工质对成为吸收式制冷技术的发展方向。离子液体具有蒸汽压近似等于零、可设计性(通过改变阴阳离子)、较低的腐蚀性、对许多极性和非极性物质均有良好的溶解性、热力学性质稳定、在200℃以下仍能稳定以液体形式存在等特性,使其有成为吸收式制冷新型工质的潜能。本文提出将离子液体1-乙基-3-甲基咪唑磷酸二甲酯([EMIM][DMP])+醇类+水的三元混合溶液作为吸收式制冷机的新型工质,对其热力学性质进行了实验研究和数据关联。采用沸点仪法测量离子液体[EMIM][DMP]+甲醇/乙醇+水所组成的二个三元体系不同浓度和温度下的汽液相平衡实验数据,结果表明两体系均对Raoult定律呈负偏差。并采用NRTL模型对本实验两个三元体系汽液相平衡进行预测,实验值与预测值的平均相对误差分别为3.09%,3.89%。采用绝热量热法测量了温度为298.15K时,[EMIM][DMP]分别与水/乙醇/甲醇所组成的三个三元体系的混合热,结果显示三个体系均为放热过程。实验结果采用Nagata-Tamura和Cibulka提出的多元方程进行拟合,用NRTL和UNIQUAC方程预测,得到了超额混合焓与组成之间的关系。采用绝热量热法测量了[EMIM][DMP]+甲醇乙醇/+水组成的二个三元体系在常压、温度范围为298.15K-323.15K、不同浓度下的比热容。本文还对实验数据进行拟合,得到定压比热容与组成、温度之间的关系,结果显示比热容与温度大体呈线性关系,随着温度的升高而增大。更多还原

【Abstract】 The technology of absorption refrigeration by employing solar energy and industrial waste heat is developing rapidly in today’s society, which is confronted with great energy strain. However, the development of technology of absorption refrigeration is held back due to the inherent weaknesses of widely used working pairs, LiBr-H2O and NH3-H2O for absorption refrigeration at present, with the features of strong corrosion to equipment, easy crystallization, toxicity etc, to name just a few. Therefore, it leads the direction of development to seek new working pairs with wider application and higher efficiency. Many unique properties of Ionic Liquid (IL), such as a nearly zero vapor pressure, ability to be designed (by changing the anion or cation), lower corrosion, strong solubility, thermal stability, consistency in existence under200℃, make it probable to be used as working pairs for absorption refrigeration. The author of this paper put forward ternary systems, with ionic liquid1-ethyl-3-methylimidazolium dimethylphosphate ([EMIM][DMP]), methanol/ethanol and water in it, as the new working pairs for absorption refrigeration, and conducted the experimental study on its thermodynamic properties.The ebulliometer was used to measure the experimental data of gas-liquid equilibrium of the two ternary systems, which contain [EMIM][DMP] and methanol/ethanol and water with different concentrations and under different temperatures. The results reveal that the two systems show negative deviation in terms of Raoult’s law. NRTL model was used to predict the data of the gas-liquid equilibrium of these two ternary systems. The average relative errors of the experimental and predicted values are3.09%and3.89%, respectively,the excess molar enthalpies (HE) of three ternary mixtures for [EMIM][DMP]+methanol/ethanol/water were measured with an isothermal calorimeter made by the author at298.15K and under the normal atmospheric pressure, which show that all the three mixed processes are exothermic. The experimental results have been correlated with the polynomial proposed by Nagata and Tamura (NT) and Cibulka. Meanwhile, NRTL and UNIQUAC equations were employed to predict the ternary systems, and found the relation between HE and the components.The specific heat capacity of ternary mixtures for [EMIM][DMP]+methanol/ethanol+water were measured by the isothermal calorimeter at the temperature ranging from298.15K to323.15K, under the constant atmospheric pressure, and with different concentrations. The data were correlated to find that the relationship between the heat capacity and the temperature.更多还原