| Popis: |
This master thesis deals with the basic problems of solar thermal systems, which are using heat transfer medium. At the beginning this thesis describes basic components of the solar system, especially their meaning and attributes. Further in the thesis are mentioned heat transfer liquids for commercial usage which are used in those systems, their basic properties and dependence on temperature. There is described the physical nature of liquid viscosity and also ways how to measure them. The same is for measurement of liquid density and thermal conductivity. At the end was made measurement of dynamic viscosity of heat transfer liquids for commercial usage at different temperatures. In practical part of the thesis were mixed samples of alternative heat transfer mediums. It was measured their thermal and physical attributes, like for example density, dynamic viscosity and coefficient of volumetric expansion. Each measurement was compared and evaluated. |
