Wall Temperature Measurements in a Full-Scale Gas Turbine Combustor Test Rig With Fiber Coupled Phosphor Thermometry

Patrick Nau,Christoph Arndt,Torsten Endres,Benjamin Witzel,Simon Görs

doi:10.1115/1.4049104

Abstract

Abstract Wall temperature measurements with fiber coupled online phosphor thermometry were, for the first time, successfully performed in a full-scale H-class Siemens gas turbine combustor. Online wall temperatures were obtained during high-pressure combustion tests up to 8 bar at the Siemens Clean Energy Center (CEC) test facility. Since optical access to the combustion chamber with fibers being able to provide high laser energies is extremely challenging, we developed a custom-built measurement system consisting of a water-cooled fiber optic probe and a mobile measurement container. A suitable combination of chemical binder and thermographic phosphor was identified for temperatures up to 1800 K on combustor walls coated with a thermal barrier coating (TBC). To our knowledge, these are the first measurements reported with fiber coupled online phosphor thermometry in a full-scale high-pressure gas turbine combustor. Details of the setup and the measurement procedures will be presented. The measured signals were influenced by strong background emissions probably from CO*2 chemiluminescence. Strategies for correcting background emissions and data evaluation procedures are discussed. The presented measurement technique enables the detailed study of combustor wall temperatures and using this information an optimization of the gas turbine cooling design.

Highlights

Pled online phosphor thermometry were, for the first time, successfully performed in a full scale H-class Siemens gas turbine combustor
Online wall temperatures were obtained during high-pressure combustion tests up to 8 bar at the Siemens Clean Energy Center (CEC) test facility
Since optical access to the combustion chamber with fibers being able to provide high laser energies is extremely challenging, we developed a custombuilt measurement system, consisting of a watercooled fiber optic probe and a mobile measurement container

Summary

Fiber Coupled Phosphor Thermometry

Authors: Patrick Nau, Simon Görs, Christoph Arndt, Benjamin Witzel, Torsten Endres. https://asmedigitalcollection.asme.org/turbomachinery/article/doi/10.1115/ ASME Digital Collection URL: 1.4049104/1091388/Wall-Temperature-Measurements-in-a-Full-Scale-Gas. A suitable combination of chemical binder and thermographic phosphor was identified for temperatures up to 1800 K on combustor walls coated with a thermal barrier coating (TBC) To our knowledge these are the first measurements reported with fiber coupled online phosphor thermometry in a full scale high-pressure gas turbine combustor. The presented measurement technique enables detailed study of combustor wall temperatures and using this information an optimization of the gas turbine cooling design. We present the first successful wall temperature measurements with fiber coupled online phosphor thermometry at the Siemens CEC test facility. Online wall temperatures could be obtained during high-pressure combustion tests up to 8 bar, using a Siemens full scale H-class large gas turbine combustor. To achieve optical access to the combustor, the fiber probe is guided through the pressure vessel and the flow box to the combustor wall. It reached all the way to the probe tip, where the nitrogen exited into the combus-

Optical measurement setup

The phosphorescence signal can be described as an exponentially decaying curve

Phosphor coating and Calibration procedures

RESULTS AND DISCUSSION

PMT gate on

CONCLUSION