The Study On Steam Dryness Controller Used In Oil Field Steam Boiler

The DC steam boiler used in oil field is the key equipment to produce the high-pressure steam. Dryness fraction is an important parameter in the safe operation of steam boiler used in oil field,and also an important indicator that affects thermal production. Dryness fraction is effected by multiple parameters,therefore,it has a certain degree of difficulty to effective control the dryness fraction. Since the introduction of steam boiler in 80s of last century,the steam boiler have gradually realized the localization,but the Dry-degree detection is still a manual test,detection is less efficient,dryness of control still remains in the original technical level. With the advanced control theory and computer technology continue to develop,it is a tendency that fuzzy control and other advanced control technology are applied to steam boiler to improve control efficiency of steam boiler control system. It is also imperative for Dry-degree detection to looking for a convenient and accurate detection method.This paper introduced a variety of measurement principles and methods of Dryness fraction,referring to the manual testing currently being used (visual colorimetry) method,applying principles of chemistry and optical,designed a dryness fraction spectral resolution online detection device. The device achieves titration process automation and intelligent analysis,the titration process and the spectral analysis are achieved automatic,after the end of the process,dryness fraction can be analyzed out without manual intervention. Experiment validated that the device has a higher detection accuracy in stable operation.Then the paper analyzed the factors that affect the dryness fraction,the dryness fraction is a strong coupling of the controlled variable,the previous single-loop PID control of anti-disturbance capability is not strong,this paper presents a model based on TS Fuzzy PID Controller,fuzzy inference is adopted by antecedent,PID control output is adopted by consequent ,TS-PID controller combines the advantages of fuzzy control and PID control,it improves the system's rapid response and anti-jamming capability.Finally,with the combine of the dryness fraction spectral resolution online detection device and TS-PID control strategy to control dryness fraction, experimental results show that Dry-degree detection and Dry-degree control have achieved good results. The design of dryness fraction spectral resolution online detection device has been successfully applied in a steam boiler of Liao he oil field.