The highest temperatures in the boiler combustion chamber are the Waterwall pipe metal temperatures. In general, the temperature on a clean side wall pipe is 75°F above the saturated temperature.

There is a temperature difference similar to 50°F-75°F between the highest pipe temperature in supercritical boiler combustion chamber and the temperature of the fluid passing through the side wall.

Whether there is a general problem in the circulation or not is determined with the pipe temperatures whose deposit forming is highly increased in the boiler pipes.

Besides, the metal temperature can increase to the metal extreme heating point.

The chordal thermocouples are useful tools to predict the problems encountered in the water wall.

The chordal thermocouple values are extracted directly from the side wall pipes. After the equipments are installed, weekly records must be taken and temperature graphics must be followed. These graphics must be taken when same burners run under the same load. Even a tiny deposit forming in water could cause temperature difference. Iron oxide layer has a heat transfer coefficient of 1/70 more than the steel.

In case a slightly increasing temperature curve is determined in the chordal thermocouples attached to the boiler, some sample pipes must be cut for further detailed analyses.