DETERMINING THERMOPHYSICAL PROPERTIES OF LITHIUM AND CALCIUM CHLORIDE AQUEOUS SOLUTIONS AS LOW TEMPERATURE SECONDARY WORKING FLUIDS
Secondary working fluids (secondary refrigerants, heat transfer fluids, etc.) are used for a variety of indirect refrigeration applications, incl. freezers in supermarkets and some applications at even lower temperatures. An ideal secondary working fluid should possess good thermo-physical properties. Besides giving sufficient freezing protection it should have good heat transport capacity, give good heat transfer and give small pressure drop for the system fluid flow. Commonly used secondary working fluids can often not be used in low temperature applications. Aqueous salts, such as calcium chloride and potassium salts are used, but not at operation temperatures below-35℃, as freezing points below -45℃ then are needed, getting too close to the eutectic temperature.However, the eutectic temperature of lithium chloride - water is below -65℃. Thermophysical properties of lithium chloride have been studied with sorption dehumidification in view at higher temperatures. This paper will focus on a literature search and some measurements to establish technically reliable thermophysical property values for aqueous solutions of lithium chloride, especially for temperatures below 0℃. The thermo-physical properties examined are freezing point, density, specific heat, thermal conductivity, viscosity. Viscosity of calcium chloride is also considered as low temperature values in refrigeration handbooks differ from some measurements recorded in literature and by author.
(A).MELINDER
Dept. of Energy Technology School of Industrial Engineering and Management Royal Institute of Technology, KTH S-10044 Stockholm, Sweden
国际会议
The 22nd International Congress of Refrigeration(第22届国际制冷大会)
北京
英文
2007-08-21（万方平台首次上网日期，不代表论文的发表时间）