Kawasaki Heavy Industries (KHI) has developed a new type of industrial gas turbine L30A. The turbine part consists of a two-stage high-pressure turbine (gas generator turbine) and a three-stage low-pressure turbine (power turbine). During the development phase, a commercial two color pyrometer system was used to measure the blade temperature under real engine conditions. The two color pyrometer is equipped with a new detector module, which can also measure lower temperatures than traditional two color pyrometer. In this way, a two color pyrometer can be used to measure the various stages of the blade. By comparing with the data of other conventional methods, the effectiveness of this method is verified. The temperature distribution of the blade surface can be easily obtained by using the two color pyrometer system, and the cooling capacity of the blade can be evaluated without spending a lot of time. This article describes the measurement and analysis process in detail.

introduction
Due to the significant progress in CFD (computational fluid dynamics) and CHT (coupled heat transfer) analysis in recent years, gas turbine engineers can design turbine components with higher accuracy in a shorter time. However, since the failure of the rotating parts of the gas turbine can cause catastrophic damage to the gas turbine, it is still of great significance to accurately measure the operating temperature of the blades. This is why gas turbine manufacturers have been working hard to measure blade temperature.

The most accurate way to obtain the surface temperature is to use a thermocouple embedded in the blade. The output is transmitted via slip ring or telemetry. Since the temperature can be directly measured with a thermocouple, it has the highest accuracy compared to other techniques described later. But wiring in the rotor and data transmission device requires a lot of time and cost. Short thermocouple life can sometimes not make up for the cost. The biggest disadvantage is the limitation of measuring points. In recent years, as the turbine inlet temperature has increased, the cooling structure of the blade has become more and more complex. Therefore, the limited number of measurement locations is not enough to fully understand the temperature distribution on the blade surface.