Several components in biomass and waste such as alkali metals result in combustion residues.
Part of them form deposits on the walls of superheaters and water walls, leading to corrosion
and lower heat output. These deposits are to be removed during operation of the power plant.
An adjusted cleaning of the deposits improves the plant’s efficiency by increased heat output
or enables a higher throughput and leads to reduced maintenance costs. Both the deposit
location and the deposit properties affect the efficiency of the cleaning. Thus, measurement
setups aim to detect the deposits online and to analyze their properties.
Laser-based diagnostic comprises the detection of deposits and their thickness by measuring
wall distances. The system can be used as stand-alone setup or in combination with different
measurement setups as well as in combination with balancing tools to predict deposit
development of large heat exchanger areas. The established measurement setup is presented
followed by the integration of the system into modern monitoring systems.
Afterwards, results are presented that were recorded during a measurement campaign at a
German waste power plant. The results are applicable to biomass fired power plants. As part
of the study several measurement setups were installed and compared. Topology plots
recorded with the laser distance sensor and an assessment of their usefulness regarding
cleaning optimization follow, both as single measurement setup and as part of a monitoring
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