The objective of the pilot plant construction is to verify the design principles, developed in an earlier project, thus creating the basis for construction of a commercial plant, i.e. larger than 100 MWt. The aim is to establish the necessary experimental fluidized bed data, for instance, knowledge on flue gas cleaning at high pressure and temperature, gas turbine corrosion/erosion problems, control conditions, thermal and environmental performance.
Since 1984 Aalborg Boilers A/S, Ris National Laboratory and Aalborg University Centre have accomplished extensive development work in relation to atmospheric circulating fluidized bed combustion. The result of this work has been the construction of a 20 MW demo plant located at I/S Midtkraft in Aarhus. The plant has operated successfully since February 90.
A project concerning pressurization of circulating fluidized bed has been carried out since 1987, partly financed by the Commission (contract EN3F-0064-DK(B)). The object of the project which has been carried out by Aalborg Boilers with the same partners was to establish the design basis for a 100-500 MW plant. The concept is based on pressurization of Aalborg Boiler's patented multi-circulating fluidized bed boiler. It is anticipated that the design principles will be competitive economically as well as environmentally.
In addition, the efforts have been concentrated on optimization of the process - i.e. analysis of the influence of the design parameters on the process conditions, such as desulphurization and NOx formation. Based on tests with a 2 MW circulating fluidized bed plant, general empirical models have been established for calculation of emission values.
The present project mainly consists of construction and test of an 8 MW pilot plant, and will be coordinated by Aalborg Boilers A/S in cooperation with Ris National Laboratory, NU-Energy A/S, the Technical University of Denmark and the Universidade do Porto.
With reference to the selection of turbo machinery for a demo plant, further analyses will be made in order to clearly explain the plant's fundamental operational capabilities. The necessary calculation tools for this have been developed during the previous project. Special attention will be paid to analyses on dynamic behaviour, for instance start, stop and load changes. When the current cyclone test has been finished, the results will be processed in order to finalize design of the gas cleaning system.
The empirical model for the calculation of emission values is based on data from an atmospheric circulating fluidized bed. The influence of the pressure has yet been included in a qualitative way only. The intention is that the test results from the pilot plant will form the basis for an improved model. In this relation further theoretical and experimental work will be required in connection with combustion of coal and coke under pressure, desulphurization under pressure, and NOx formation under pressure.
Funding SchemeCSC - Cost-sharing contracts
2800 Build Lyngby
9220 Ålborg O
2628 BL Delft