| Popis: |
When designing pipeline networks, the knowledge of loss coefficient respectively resistance coefficient when flowing through various types of fluids through hydraulic elements, e.g. control valves, which are often used in the engineering and energy industry. Their specification is performed mainly experimentally. However, there are applications where the experimental approach of their determination is unrealistic and then mathematical methods can be considered. The article presents a methodology for determining the static characteristics of the DN25 control valve for different opening. The measurement of the characteristics was performed with an incompressible flowing medium - water and with a compressible flowing medium - air. Subsequently, a comparison of measurement and evaluation of loss and flow coefficients was performed. The measured values will be further used to verify the results of modelling and to precisely define mathematical models, so that the models can be subsequently used at vapour flow, where the experimental method of determination is difficult. Frequent applications are found in the flow of saturated and superheated vapour through control valves. |
