【作者】 晏双华；

【导师】 赵宗昌；

【作者基本信息】 大连理工大学 ， 化学工程， 2009， 硕士

【摘要】 热泵是一种重要的节能装置,它兼具高效、节能、环保等优点。随着经济的发展,人们环保意识的加强和能源结构的调整,热泵技术的发展越来越受到重视。近年来热泵的工质对的研究越来越成为热点。离子液体被称为一种绿色溶剂,具有化学性质稳定、液程宽、蒸汽压低、并且能和很多有机或无机溶剂相溶等特点,近年来受到人们的广泛关注。本文研究了离子液体1-乙基-3-甲基咪唑磷酸二乙酯（[EMIM][DEP]）分别与水、乙醇、甲醇组成的二元体系的热力学性质,主要做了如下工作:在实验室内合成离子液体[EMIM][DEP],用泡点法测定了该离子液体分别与水、乙醇、甲醇组成的三种二元溶液在不同离子液体浓度、不同温度下的蒸汽压数据,数据显示其蒸汽压均对Roault定律呈负偏差;利用NRTL模型对三个二元体系的蒸汽压数据进行了关联,拟合得到其模型参数,并且实验数据与拟合值的平均相对误差分别为2.72%、2.36%、1.26%,说明NRTL模型适合于本文研究的含离子液体的二元体系的汽液平衡的计算;实验测定以上三种溶液在离子液体摩尔浓度分别为0.2、0.4、0.6、0.8,温度为25℃时的混合热,结果显示该离子液体与以上三种溶剂的混合均为放热过程。这些热力学性质特点符合热泵工质的要求。通过测量离子液体及含离子液体的溶液的比热Cp发现,溶液的Cp随温度的升高线性增加。实验测定了以上三个二元体系从25℃～50℃的密度和粘度。结果显示当所研究的溶液浓度一定时,其密度随温度的升高而线性降低,但是变化的幅度很小。离子液体的粘度比普通溶剂的粘度要大的多,25℃时[EMIM][DEP]的粘度约为同温度下水的粘度的300倍,但是随着温度的升高,其粘度随之迅速降低。随着H₂O,C₂H₅OH,CH₃OH逐渐加入到离子液体中,溶液的粘度迅速降低。对于一定浓度的溶液,其粘度随温度的升高迅速降低,本文采用Arrheniusde方程对三个二元体系的粘度实验数据进行了拟合,实验与拟合值平均相对误差分别是2.42%、1.86%、2.15%。综合以上结果,离子液体[EMIM][DEP]分别与H₂O,C₂H₅OH和CH₃OH构成的二元溶液具有作为热泵新工质的潜力。更多还原

【Abstract】 Absorption heat pump is an important equipment for recovering industry waste heat.It has characteristics of high efficiency,energy saving and environmental protection.With economic development,strengthening of people’s awareness of environmental protection, there has been a growing interest in heat pump technology.The development of new working pairs has also been paid more and more attention.Ionic liquid is a kind of room temperature melted salt which consists of organic cations and inorganic anions.They have many advantages such as a negligible vapor pressure,strong solubility in many organic substances,and stable in a large temperature range.As green solvents,ionic liquids have a potential application in chemical industries in recent years.In this paper,binary systems containing ionic liquids are considered as new working pairs in absorption heat pumps.[EMIM][DEP]was synthesized in the lab.Vapor pressures for the three binary systems（[EMIM][DEP]+H₂O/C₂H₅OH/CH₃OH respectively） with different contents of[EMIM][DEP]were measured at different temperatures,The experimental data all showed a considerable negative deviation from Raoult’s law.The vapor pressure data were correlated by NRTL model.NRTL parameters were obtained.The average deviation between experimental data and correlated ones were 2.73%,2.36%,1.26% respectively.The mixing heat（H^E） for those three systems were also measured,the H^E data all showed that the mixing process were exothermic process.Heat capacities for the three systems were also measured in this paper.In the experiment,Densities and viscosities for the three binary systems mentioned above were measured at different temperature（From 25℃to 50℃）.The experimental data of densities showed a linear relationship against temperature.The viscosities of[EMIM][DEP] were obviously greater than those of H₂O,especially when the temperature was low.At the temperature of 298.15K the viscosity of[EMIM][DEP]is about 301 times of H₂O.Therefore when H₂O/C₂H₅OH/CH₃OH was added into[EMIM][DEP],the viscosity of the mixture decrease sharply.And as expected,for the system at the same composition,the viscosity of the system decreases sharply with the increase of the system’s temperature.The experimental viscosities were correlated using Arrhenius equation.The results indicated that the Arrhenius equation can be used to describe the viscosity of the binary system containing [EMIM][DEP]+H20 well.The average deviation between experimental data and correlated ones were 2.42%,1.86%,2.15%respectively.The results showed that ionic liquid[EMIM][DEP]+H₂O/C₂H₅OH/CH₃OH have potential as working pairs.更多还原