The long service life of incineration plants means that the assumptions made at the planning stage regarding fuel properties and fuel availability change in the course of operation and the original design range of the plant is abandoned.
This change in fuel properties is of course much more likely with biogenic fuels than with fossil fuels. The change in physical as well as calorific fuel properties leads to problems and negative effects on the consistent, trouble-free operation of a boiler plant.
The change in the ash softening temperature is also of particular importance, and the resulting caking in the combustion chamber repeatedly triggers optimisation measures in which we actively participate.
- Overall analyses of fuel flexibility with determination of the actual practical limits of an existing plant
- Examination of the permissible limits of the permit, the plant technology, the ecological impact and the economic efficiency
- Comparison of the limits thus determined with the extended/future requirements (e.g. by extending the waste wood fraction) – if the extended requirements exceed the actual limits, we design an optimisation path together with the client
Optimisation path concept
We carry out the conception of the optimisation path as a joint design work with you.
- Identification of the given bottlenecks that lead to limits
- Removal of these bottlenecks through appropriate measures – always following the basic principle of “minimally invasive” – this means the combination of control and process engineering measures
- Design of the modifications (calculation, simulation, engineering) – in terms of control and process technology
- Consideration of the permissible limits of the permit, the plant technology, the ecological impact and the economic efficiency
Implementation of optimisation measures
The implementation is carried out step by step or as a complete package – depending on the extent, scope of the approval situation – and of course in close coordination with the plant in order to make optimal use of planned shutdowns. All measures are coordinated with the plant safety concept. We frequently carry out the following measures:
- Design of the higher-level control system, renewal of the firing rate control system – for example with EPOC®.
- Extension of sensor technology, repair or renewal of actuator technology
- Avoidance of air leakage
- Adaptation of fuel conveying technology
- Increase of the degree of automation, e.g. by additional level sensors for equalisation of the delivery, dynamic speed adjustment of screw dosing to avoid fluctuating delivery rates.
- Adjustment of the combustion chamber pressure to prevent burn-back
If calorific fuel properties are changed, the firing system must be adapted to the new conditions. A description of this topic can be found under Load range extensions.