In the area of heat supply, load range expansions usually stem from the need to follow the reduced heat demand with generation as optimally as possible in summer operation. This means a reduction of the minimum load.
The opposite requirement often arises in the continuous operation of boiler systems. For our customers, the question arises as to how high the load can be increased with reasonable effort and how it can be operated as a continuous load.
The task of extending the load range is thus related to the task resulting from fuel flexibilisation. The extension of the design load range of the boiler plant is associated with extensive work to understand and revise the firing system.
The following measures take place frequently. All measures are of course coordinated with the plant safety concept.
- Analysis to determine the limits of the existing plant technology, identification of possibilities to adapt the firing system
- The consideration of the firing system includes the combustion chamber incl. the system technology and the firing rate control as the “intelligence of the firing system”.
- Development of a concept for the adaptation or renewal of the firing rate control (EPOC®) and for the utilisation of the process-engineering possibilities that exist according to the analysis of the combustion chamber.
- Derivation of the specifically suitable bundle of measures – in addition to all measures on the furnace control system, the following are frequent: adaptation of refractory lining, adaptation of air preheating, change in recirculation gas quantity, fuel or air trimming.
- Requirement: maximum firing efficiency, minimised emissions, long travel times