Diagnosing Severe Air In-Leakage in a 500-MW Power Plant
How data-driven diagnostics and helium leak detection restored 350 MW of lost generation eliminating up to $300,000 per day in lost revenue
Condenser air in-leakage is one of the most significant causes of reduced power plant efficiency. By degrading vacuum conditions, increasing turbine heat rate, and restricting output, unchecked air ingress can quietly force major derates while driving significant financial losses. Air in-leak is particularly dangerous because it can be hard to locate the source, (requiring investigation of all components under vacuum) and it can worsen over time as the damaged area expands.
When a 500-MW gas-fired unit began experiencing a sustained increase in air in-leakage and condenser backpressure, plant operators recognized the need for to bring in outside experts for diagnostics and leak detection. Historical performance data revealed patterns consistent with a worsening physical leak rather than a leak that varied under transient operating conditions, enabling engineers to significantly narrow the search area before deploying targeted helium leak detection.
The investigation ultimately led to a crack that had formed in the condenser’s expansion joint that, once repaired, immediately reduced air in-leakage and restored full generating capacity. This case study demonstrates how integrating continuous monitoring with expert diagnostic strategy can dramatically shorten troubleshooting timelines, diagnose the root cause of condenser performance issues, and protect plant profitability.
Read the full condenser air in-leakage case study
About the Author: Collin Eckel
Mr. Eckel is the Site Manager at the Bionetics CESG Division. At Bionetics he has been actively engaged in the analysis of plant and Bionetics instrument data, supporting customers and designing diagnostic software for RheoVac users. Collin contributes to Bionetics continuing efforts to improve instrument performance by refining our calibration and instrument preparation methods, and developing software improvements. He has visited numerous power plants, assisting customers with troubleshooting and participating with other Bionetics staff in the inspection and evaluation of condensers. He is a member of the Bionetics team conducting the installation, monitoring and data analysis of our advanced condenser monitoring systems.