EVALUATION OF THERMOPHYSICAL PROPERTIES OF ETHYL ALCOHOL BASED SECONDARY FLUIDS

摘要

Ethyl alcohol (ethanol) based secondary fluids are commonly used in different types of indirect refrigeration systems in Scandinavia due to low toxicity, relatively good thermophysical properties and environmental regulations regarding leakage. Ethyl alcohol based commercial products available in Scandinavia contain different types of denaturing agents but no corrosion inhibitors. The most common denaturing agents are isopropyl alcohol (isopropanol), n-butyl alcohol (n-butanol), methyl ethyl ketone and methyl isobutyl ketone. Property measurements recently performed at KTH showed that presence of these additives in ethyl alcohol based secondary fluid improved thermophysical properties especially in terms of specific heat, thermal conductivity, and dynamic viscosity. Additionally, it was found that the specific heat capacity tendency is different than previously reported.