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Thesis for the Degree of Master of Science

 

Year 2008
Janne Kallioniemi

Process monitoring application to a biopower plant


Process industry companies are nowadays forced to develop more efficient processes due to tightening competition, high prices on the energy market, and environmental and fuel policies. The target of production plant suppliers is to maximise power plant availability and efficiency, and to minimise production costs and environmental impacts. The most essential feature is to respond to the demand for electric and thermal power in a biopower plant. In addition, it is important that the live steam pressure and temperature values are correct. If the live steam pressure increases too much before a steam turbine, then the live steam generated in a steam boiler may not be utilised completely, thus reducing the efficiency of the plant. In such a case the live steam is by-passed via a steam turbine reduction valve. Use of the reduction valves always decreases the plant’s efficiency.

This study analyses the control system of a biopower plant and its operations. Measurements and controllers that affect the fluctuation of live steam production are investigated using process monitoring methods such as principal component analysis (PCA). Measurements and process values of the biopower plants supplied by Wärtsilä Biopower are utilised in the experimental part.

In the literature part of the study, the different process monitoring methods are introduced. Principal component analysis (PCA) and partial least squares (PLS), their modifications and applications are presented in more detail. Biopower plants, components and fuels are also illustrated in the literature part. The chapter concerning combustion technology discusses burning processes in general, grate combustion and emissions.

The experimental part of the study deals with process measurements and controllers, which affect fluctuations in a biopower plant process and in live steam production. Static and recursive principal components analysis are used in the research. Different control systems and controllers of the biopower plants are also presented in the experimental part. Based on this study, the measurements, controllers and process parameters that have the greatest effect on the biopower plant process are identified. In conclusion, ideas for improving process control are presented for future development.


This info last modified 22 Nov 2017 by Jerri Kämpe-Hellenius