Procedure

The starting point of our strategy for target-oriented prevention of combustion oscillation in a combustion system is to compile a thorough understanding of the underlying causal mechanisms.

Diagnosis

In this area, we conduct calculations as well as measurements on each combustion system, which we can record using a DAT recorder. We can then carry out comprehensive analysis work at a later time. In the primary analysis, acoustic natural frequencies and modes are considered, together with the linked oscillating heat-release from the flame. To identify Eigenmodes in a combustion system, IfTA GmbH offers two processes: experimental modal analysis and numerical modal analysis. Alongside these diagnosis methods, our product Argus OMDS also comes into its own, enabling us to investigate phenomena which are difficult to observe, occurring as they do only sporadically, e.g. at certain ambient temperatures or in response to other specific conditions.

Devising a solution

Following this, it is possible to devise target-oriented, efficient and cost-effective courses of action to help prevent these phenomena from occurring. Depending on the problem and its cause, this may involve the use of a passive or an active measure.

With the first of these methods, in most cases the actual physical structure of the combustion system is modified in such a way that oscillations can be prevented. In contrast to this, with an active solution, the oscillation level is measured and influenced via a control loop by means of sensor, controller and actuator in such a way that the oscillation is suppressed. The latter method is especially used in cases where build modifications would prove very costly or time-consuming, or in cases where the oscillation problem is very complex, having for example several excited frequencies.