Absorption Refrigerating Machine, Heat Pump and Dehumidifier Using Water+Ethylene Glycol+Lithium Chloride System and Water+Lithium Chloride System

2002 Fiscal Year Final Research Report Summary

• Project/Area Number: 13650239
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Thermal engineering
• Research Institution: Kansai University
• Principal Investigator: UEMURA Tadashi Kansai University, Faculty of Engineering, Professor, 工学部, 教授 (50067568)
• Co-Investigator(Kenkyū-buntansha): IYOKI Shigeki Kansai University, Faculty of Engineering, Associate Professor, 工学部, 助教授 (60098100)
• Project Period (FY): 2001 – 2002
• Keywords: Absorption refrigerating machine / Absorption heat pump / Absorption heat transformer / Coefficient of performance / Dehumidifier / Lithium chloride / Ethylene glycol / Bacteria

Research Abstract

This investigation was undertaken to examine whether the water + ethylene glycol + lithium chloride system (lithium chloride: ethylene glycol=4.9 : 1.0 mass) are suited for absorption refrigerating machines and heat pumps. Measurements of the physical properties (density, viscosity, surface tension, solubility and vapor pressure) and the thermal properties (heat capacity and heat of mixing) of lithium chloride+ethylene glycol aqueous solutions were carried out at various temperatures and absorbent concentrations. Empirical formulae of the density, viscosity, surface tension, solubility and heat capacity of these ternary systems were obtained from experimental data. The vapor pressure data were correlated as an Antoine-type equation. The hear of mixing data were correlated as a Redlich-Kister type equation. A theoretical analysis of the coefficient of performance was undertaken to examine the performance characteristics of the water + ethylene glycol + lithium chloride system. The coeff icient of performance for absorption refrigerating machines and absorption heat transformers was calculated using the enthalpies at various temperatures, pressures and absorbent concentrations. Two types of absorption refrigerating machines, two types of absorption heat transformers, two types of hybrid cycles, and a dual cycle were adopted for simulation. The performance characteristics of these systems were compared with those of the water + lithium bromide system, the water + lithium chloride system, the water + lithium bromide + ethylene glycol system and the water + lithium bromide + diethylene glycol system. Furthermore, by changing flow rate of lithium chloride aqueous solution, the number of bacteria in entrance and exit of this dehumidifier was examined. Bacteria were not detected from after dehumidifier starting operation 90 minutes. In the dehumidifier using lithium chloride aqueous solution, it was proven that there was sufficient sterilizing power. Minimum inhibition concentration (MIC) of some kinds of surface active agents as additive of lithium chloride aqueous solution using bacteria sterilizer were examined.