Benefits of extended thermocouple installations on HRSG tubes

If your plant suffers from frequent failures, installing additional thermocouples can prove to be invaluable when assessing the actual root cause of the failures.

During a recent Tetra project in the Middle East, a number of thermocouples were installed at the top and bottom headers joining economizer tubes which had previously been subject to failures.  The thermocouples were positioned around one of the failure locations to clearly map temperature distributions on the tubes, during various operational conditions.  Tetra built looms of K-type weldable cable that was routed inside the boiler and capacitance discharge welded to the tubes of interest.  Although the front rows of tubes were very easy to attach the thermocouples to it was felt that more information would be obtained by getting the group around the failed area. Thermocouples were welded to the tubes in the area where fins had already been welded but then removed as part of the tube manufacturing process. 

After the installation, the plant could easily log various operating conditions and send the data back to the Tetra office for analysis. 

For more information about thermocouple installation contact Dave Moelling dave.moelling@tetra-eng.com (Americas) or Mark Taylor mark.taylor@tetra-eng.com (EMEA).