NDE Methodology for Identifying Condenser Design Deficiencies

Harpster, J.W.
“NDE Methodology for Identifying Condenser Design Deficiencies” EPRI Balance of Plant Heat Exchanger NDE Symposium, Big Sky, MT, June 26-28, 2006.

Abstract

Application of NDE methodology, appropriate condenser monitoring and diagnostic instrumentation, and a condenser model and theory under development since 2001 are used to help identify or confirm condenser design issues.  These design problems are the cause for inadequate steam space venting and the accumulation of noncondensable gases in pockets within the tube bundle; both contribute to a condition generally referred to as air binding (AB).  The result is diminished heat transfer rates leading to excess condenser pressure, reduced thermal efficiency and in many cases, high dissolved oxygen (DO) and other gases that can lead to corrosion, forced outages and reduced plant life.

Measurements on numerous power plant condensers using diagnostic equipment employing a MultiSensor Probe (MSP) have been made that allow, determination of the properties, make-up and flow rate of water vapor and noncondensables being removed from condensers through the vent line by the condenser exhauster(s).  For all condenser configurations, the model and theory identify the behavior of these gaseous components in the Air Removal Section (ARS) of the condenser and within the main steam condensing region of the tube bundle.  Discrepancies between expected response from condenser dynamic behavior and those determined from actual MSP and other plant measurements are shown to be related to well understood condenser configuration issues.