In order to conserve a good efficiency, the fin tubes of the ACC have to be clean periodically. A good question you could ask could be: When to clean? How to know that it’s time to clean? What key figures can I follow?
The most obvious control is Visual control : if the fouling is visible on your fins then it’s time to clean!
You can also measure the internal static pressure evolution inside your ACC. If the pressure goes up gradually, it shows that the air flow trough the fins drops: it’s time to clean! The internal static pressure can be measured with a differencial pressure recorder, but there is also a simpler trick using the door to access inside the ACC: If the torque required to open this door is more difficult than usally, it is a sign that the pressure inside the ACC is higher!
You also have to follow the vaccum level (in bar) in ACC. If it drops progressively, it’s also time to clean! Indeed, when the fin tubes are fouled, the ACC condenses the vapor into water slower, which causes a pressure increasements (vacumm droping) into the vapor circuit.
Finally, in following your production of electricity (in MW), you will definitly know when it’s time to clean! Indeed, when the vaccum level drops, the pressure differential on the turbine drops, which explains the productivity loss.
All these measurments depend on environnemental conditions (temperature, relative humidity…), but also on the powerplant using conditions such as loading or fan speed.
Therefore we recommand to clean periodically, at least once a year after the pollen season.
In all case, the more often you clean, the easier it is!