How often to clean an exchanger ?

To maintain good efficiency, the finned tubes of the Air-Cooled Condenser (ACC) should be periodically cleaned. The key questions to ask might be: When should you clean your ACC? How often? How do you know when it’s time to clean? What data should you measure and track?

Cleaning Your ACC: Visual Inspection

The first and most obvious check is a visual inspection: If the fins are visibly dirty, it’s time to clean!

Cleaning ACC: Pressure and Electrical Output Measurement

You can also measure the evolution of internal static pressure inside your ACC. If the pressure gradually increases, it indicates that airflow through the fins is decreasing: it’s time to clean! Static pressure can be measured with a differential pressure recorder, but there’s also a simple trick by opening the access door inside the ACC. If opening this door becomes increasingly difficult, it is a sign that the static pressure in the ACC is increasing. It’s time to clean!

Additionally, monitor the vacuum level (in bar) in the steam manifold. If it gradually decreases, it’s also time to clean! Indeed, when the finned tubes are dirty, the ACC condenses steam into water more slowly, causing an increase in pressure (vacuum drop) in the steam circuit.

Lastly, by tracking your electricity production (in MW), you’ll definitively know when it’s time to clean! Indeed, when the vacuum level drops, the pressure differential across the turbine decreases, explaining the loss of productivity.

Cleaning ACC: A Routine Necessity

All these measurements depend on environmental conditions (temperature, relative humidity, etc.), as well as on the operating conditions of the power plant, particularly the load or fan speeds. Therefore, we recommend periodic cleaning, at least once a year after the pollen season (usually spring).

In any case, the more frequently you clean, the more effective it is!