FAST RESPONSE TEMPERATURE MEASUREMENT WITHIN A GAS TURBINE

摘要

A fast response temperature probe (1) which may be used for a method for measuring an instantaneous temperature of a periodically changing fluid flow within a gas turbine is proposed. The temperature probe (1) comprises a substrate (5) and a resistive element (3) arranged at a surface of the substrate (5). Therein, at least at a surface of the substrate (5) contacting the resistive element (3), the substrate (5) comprises an insulating material having a thermal product of less than 1.5 kJ/(m2K sqrt(s)). Advantageously, the substrate or at least its surface if made from polyamide-imide such as for example fibre-reinforced Torlon© 5030. The temperature probe may allow to measure instantaneous local temperatures of very fast fluctuations of more than 50 kHz at high spatial resolutions of e.g. less than 0.5 mm2. For measuring the instantaneous temperature of a periodically changing fluid flow, the temperature probe (1) is positioned at a position within the fluid flow and then a first set of temperature measurements is acquired. The temperature probe is then set at a different temperature near the mean temperature for example by inducing a different constant heating current through the resistive element of the temperature probe. Subsequently, a second set of temperature measurements is acquired. Finally, the instantaneous temperature may be determined by correlating the first and second sets of temperature measurements taking into account the periodicity of the periodically changing fluid flow.