Fuzzy control and expert systems for regulation of biogas reactors
Anaerobic biogas digesters are often manual regulated. This manual regulation is based on evaluation of data from the process, intuition, experience and rule of the thump. It is possible to transfer this kind of regulation into a more automatic regulation, using fuzzy regulation.
The project objective is development of a prototype automatic regulation system for biogas production systems, based on fuzzy-control and expert system technology. The system development will be based on experience from previous EFP-projects on modelling and control of biogas processes, combined will hands-on experience from Danish biogas plants. The system development will be the existing manual control strategies, combined with results from experimental work with biogas processes and anaerobic digestion models in previous EFP-project etc. The manual control strategies are in general based on evaluation of actual measurements and on-line data, intuition, experience and rules of thumb. These strategies can be transformed to linguistic rules in order to from fuzzy regulation and expert systems. Project plan: 1) Litterature update. 2) Definition and development fuzzy rules for biogas processes. 3) Development of sub-models for estimation of important process parameters. 4) Elaboration of a proto-type fuzzy control system. 5) System verification. 6) Experimental test in laboratory scale. 7) Dissemination of project results. The project will be carried out in cooperation between the Danish Technological Institute, Nellemann, Nielsen og Rauschenberger A/S, Burmeister og Wain Scandinavian Contractor A/S and the joint biogas plant in Filskov and one additional plant. NeuroTech A/S will be responsible for software development. The project will be closely coordinated with previous and running project at Dansk Teknologisk Institut and Technical University of Denmark on modelling and regulation of biogas processes. The project results are planned to be implemented at an existing joint biogas plant at a later phase. Initially as a kind of 'advisor' program, which advises the process operator concerning process malfunctions and optimal feeding patterns based on available substrates. A detailed report will be elaborated at the end of the project, together with a system evaluation from process operators and a popular paper in Danish Bioenergy
Through this project, a state of the art on fuzzy regulation of anaerobic digestion has been made. A set of rules for fuzzy variables, and fuzzy models has been developed. This has been implemented into a prototype regulation system, and the system has been tried on data from a full-scale digester. The strategy for the regulation is a stepwise regulation in three steps, which influence each other. In case of lack of data from the process, it is possible to regulate the digester (maximise gas production) using only the lowest regulation level in the system. The input data is expected biogas production from the raw material, and the output is regulation of the mass flow to the digester. If more data is available such as volatile fatty acid concentration and methane concentration, the next level of regualtion will be active to stabilise the digester. The prototype system has been tested on full-scale digesters as well as on laboratory digesters. The system reacts qualitative as intended, and the concept can handle the complex system and make it more manageable. The test shown that the system can bee used in practice, as it is very robust aginst 'outliners', which are peaks in the data and not a expression for the trend in the process
Key figures
Category
Participants
| Partner | Subsidy | Auto financing |
|---|---|---|
| Energinet | ||
| Burmeister & Wain Scandinavian Contractor A/S | ||
| NIRAS A/S | ||
| Filskov Energiselskab |
Contact
Postboks 141
DK-2630 Taastrup, Denmark
Hamann, Finn ; Projektleder: Jungersen, Gert (cand.scient.), 43504350, gert.jungersen@dti.dk
Øvr. Partnere: Elsamprojekt A/S; Burmeister og Wain Scandinavian Contractor A/S; NIRAS A/S; Filskov Energiskelskab
