Experimental study on ice intensity and type detection for wind turbine blades with multi-channel thermocouple array sensor

Abstract

A multi-channel thermocouple array (MCTCA) sensor has been fabricated and tested for in-situ monitoring of the temperature variation under icing conditions for wind turbine blades. The obtained temperature data is analysed as a tool to predict the icing intensity (g m−2) and type (rime and glaze) with respect to the temperature gradients. The tests are performed in an environmental chamber with a water spraying system. The temperature of the chamber is set to −15 °C to ensure the sprayed water is supercooled before reaching the apparatus surface. Based on the various tests, the following conclusions can be drawn. Firstly, the MCATA can successfully predict icing events where the maximum temperature rise is monitored as 11.9 °C for 2 mm and 9.8 °C for 3 mm resin thicknesses with the same amount of accumulated ice. Secondly, this study suggests the temperature change per unit mass as an indicator of the ice intensity. Severe icing events can be expected when the indicator converges to zero. Finally, this study found that the surface temperature gradient is changed over time due to the amount of latent heat released where the two different environmental conditions, −15 °C and −5 °C, are considered. It could be used to evaluate the ice types.