APPLICATION OF AN EXPERT-SYSTEM TO THE DESIGN OF FURNACE OF A CIRCULATING FLUIDIZED-BED BOILER

The design of a boiler using a new technology, i.e., circulating fluidized bed combustion, requires a considerable amount of expertise, which is a combination of experience, knowledge of the subject, and intuition. Boiler vendors, who are required to prepare a large number of proposals, rely heavily on the skill and judgment of their senior (expert) designers. An artificial intelligence based expert system can greatly simplify this task. This system can assist expert designers to store their experience and decision-making skill through the code of a computer program, which remains intact and ready to apply their skill uniformly and rapidly to all designs when required. This may allow novice designers to carry out routine proposal designs, freeing the experts to improve current designs. The present paper gives an illustration of the use of expert systems to the design of only one aspect of the furnace, which is furnace cross section. It shows that in addition to the standard method of determining the furnace area from the fluidization, the design can take advantage of previous experience, which lists grate heat release rate and other relevant parameters. The expert system also modifies the calculated value to meet different concerns of the boiler purchaser and/or his consultants. Finally the expert develops a compromise of different considerations and requirements with importance attached to them. The paper also shows how the design will change when the importance attached to a particular constraint is relaxed.