- 學位論文
乙二醇(EG, DEG, TEG, T4EG, PG, DPG)水溶液及鹽類(LiCl 或LiBr) + (DEG 或TEG)水溶液之密度及黏度量測研究
Density and viscosity measurements of aqueous glycol (EG, DEG, TEG, T4EG, PG, DPG) solutions and aqueous (LiCl or LiBr) + (DEG or TEG) solutions
摘要
液體除濕劑之特性對控制水氣含量有重要的影響，直接關係到除 濕的效率，而液體除濕劑主要可分為無機鹽類與有機醇類水溶液，但 是混合溶劑除濕液於文獻中鮮少被研究，以致於數據上之缺乏。本文 提供有機醇類(EG, DEG, TEG, T4EG, PG, DPG)與混合溶劑除濕液(LiCl or LiBr)/(DEG or TEG)/H2O 之密度、黏度數據，濃度範圍為鹽類(4 ~ 25 mass %)，有機醇類(20 ~ 80 mol %)，溫度為30 ~ 70 oC。實驗設備 方面，密度採用Anton Paar SVM 3000，量測範圍為0.65 ~ 3 g·cm-3； 黏度採用Cannon-Fenske Routine Viscometer 毛細管黏度計量測。對於 醇類水溶液之密度與黏度採用Redlich-Kister equation 之過剩體積及 過剩動黏度之模式計算；而混合溶劑密度方面，因含有電解質，採用 Söhnel and Novotný (1985, 1988)所提出之經驗式並加以改良來計算本 研究系統之密度，黏度方面採用Wang et al. (2004)提出之模式計算。 密度之增減會影響蒸汽壓之變化，黏度則直接會影響其除濕效果，與 所需驅動能量的大小，本研究之數據可作為設計除濕設備之基礎參考 數據。
並列摘要
The absorption of water vapor by means of liquid desiccant may offer advantages in comparison with air-cooling dehumidification, both in industrial and specialized application. Liquid desiccants in absorption dehumidification systems are aqueous solutions of either aqueous salts, such as lithium chloride (LiCl), lithium bromide (LiBr), or organic compounds such as diethylene glycol (DEG), triethylene glycol (TEG), propylene glycol (PG), dipropylene glycol (DPG), and tetraethylene glycol (T4EG) (Chung and Luo, 1999). For the rational design of the absorption dehumidification system, the thermodynamic properties such as vapor pressure, density, viscosity, and heat capacity of the liquid desiccants are required. However, the experimental data such as vapor pressure, density, viscosity, and heat capacity of aqueous organic desiccants are very few in the literature. The density, viscosity of the mixed-solvent desiccants have been studied of temperature ranging from 30 to 70 0C. The mixed-solvent desiccants are aqueous-organic systems with salt. The salts chosen are lithium chloride (LiCl), lithium bromide (LiBr). The organic solvents are diethylene glycol (DEG), triethylene glycol (TEG). Two ternaries (salt/glycol/water) were selected for study. For each ternary system, four system of which (4-25 mass %) salt mixed with various glycols (20 ~ 80 mol %) were studied. In the equipments of experiment, we adopt the equipment of Anton Paar SVM 3000 and Cannon - Fenske Routine Viscometer to measure the densities and viscosities of solution. The Redlich - Kister equations for the excess volume and the excess kinematic viscosity were used to model the measured density and viscosity of aqueous glycols. For the salt/glycol/water systems, we adopt the model proposed by Wang et al. (2004). The increase and decrease of densities and viscosities will influence the change of vapor pressure and the efficiency of dehumidify. The thermodynamics properties measured in this study can be used as the data base for design dehumidifier process using mixed-solvent desiccants as absorbents.