A Simulation Study on Boiler Fault Diagnosis Expert System

The boiler is one of the key parts of power station. Monitoring the operation of the boiler automatically, continuously and accurately is very important. In case of malfunctions, an expert system might be helpful to find the sources of faults, and thereafter will assist the operator to act correctly and to prevent the fault from further development.In this paper, a simulation study of an expert system, which can diagnose the running faults of boiler system, is conducted. Shallow and deep two-layer knowledge base structure is used in this two layers of knowledge base. So. this kind of expert system can overcome the disadvantages of the old types of expert systems, which are only able to deal with experience rules base.A simulator of power boiler is used for the research on fault diagnose expert system. This boiler simulator gives all necessary information for the diagnosis. The knowledge base of expert system is built in hierarchies, so the speed of reasoning may be invreased. After the reasoning the

Fault Diagnosis for Non-linear System Based On Adaptive Fuzzy System

Although lots of valuable results for fault diagnosis based on model have been achieved in linear system, it is difficult to apply these results to non-linear system due to the difficulty of modeling the non-linear system by analysis. Adaptive Fuzzy system provides a way for solving this problem because it can approximate any non-linear system at any accuracy. The key for adaptive Fuzzy system to solve problem is its learning ability, so the authors present a learning algorithm for Adaptive fuzzy system, which can build the system's model by learning from the measurement data as well as experience knowledge with high accuracy. Furthermore, the experiment using the learning algorithm to model a servo-mechanism and to construct the fault diagnosis system based on the model is carried out, the results is very good.

A Simulation Study on the Clouds Microphysical Processes of Heavy Precipitation in Hebei Area Caused by"Lekima"

During the period of the super typhoon"Lekima"(No.1909)landed on the coast of North China,a high-resolution numerical simulation study was carried out with the WRF model on the clouds microphysical process of heavy precipitation.The results showed that(1)the water vapor convergence tended to develop and strengthen on the way forward of typhoon center,and the evolution of water vapor convergence zone was closely related to the development of typhoon asymmetric structure,and had a good corresponding relationship with the falling zone of the rainstorm.(2)The eastern coast of Hebei was located in the big-value area of water vapor transport belt in the northwest quadrant of the typhoon.Below 850 hPa,northeast wind appeared,and warm humid water vapor was transported from marine area to terrestrial by typhoon.Affected by upper-level westerly trough,westerly wind was dominated above 700 hPa,and water vapor convergence was transported from low level to upper level,and several rainstorm center appeared.(3)In the spiral rain bands of typhoon,the big-value center of graupel particles cooperated with the warm cloud enriched with water content,and the ground would produce a center of heavy precipitation,and the precipitation center of pure warm cloud appeared in 117.5°E.This phenomenon rarely occurred during continental cloud precipitation.Therefore,the contribution of warm cloud precipitation mechanism to the typhoon spiral rain belt should be emphasized.