Measurement of steam quality for the control of steam-generating collectors

A safe operation of steam generating parabolic trough collectors under transient weather conditions requires a control of the specific enthalpy of a two-phase flow. Such a control depends on a measurement of the steam quality. This contribution presents the design of a capacitance voidmeter for this purpose. It allows the measurement of the steam fraction of a two-phase flow in horizontal pipes that is independent from the flow pattern. Experiments performed over the relevant range of parameters show a reliable operation and accurate results