| The article content mainly contains two parts,the first part of this paper introduces the design of monitoring and control system of industrial boilers; the second part is a detailed introduction about the way of prolonging the using life of zirconium oxide.The first part: aiming at some state-owned three 35t/h steam boiler in Huludao city Liaoning province, this paper puts forward a set of solutions based on The SHCAN2000 model field bus control system. With 35T/h industrial steam boiler as the research object, combining theory with practice, respectively for boiler water loop and burning process control circuit of the system is analyzed and the corresponding control scheme are acquired. The software and hardware system structure of The SHCAN2000 model field bus control system are detailed Discussed and the application process for the software and hardware of monitoring and control system of industrial boilers are designed and realized. At the same time, the first part also introduces the way of finishing the PC operating station and the site of the control unit.This system use high stability and reliability of the SHCAN2000 series intelligent measurement as the controller of site control layer which is the combination of PLC and Loop adjustment. And use the Can bus technology to realize the communication between the PC operating station and the site of the control unit. The system can realize the automatic of various circuit control function, automatically data acquisition, friendly human-machine interface, data report of the automatic generation of function, etc. The system has achieved successful application and good application value, with powerful control function and good control effect.The second part: this paper, which is based on the background of industrial boilers and the purpose of prolonging the service life of zirconium oxide, propose the control scheme the soft measurement oxygen gas which is based on precise wind/coal ratio curve + PID controller, instead of the application of zirconium oxide, through analyzing the reasons of shortening service life of zirconium oxide. The wind/coal ratio is the key to guarantee to achieve economic burning. The combustion process control's difficulty is how to search the wind/coal ratio within various operation condition of boiler. According to the steady-state operation records data for wind and coal in different conditions to form precise wind/coal ratio in this paper, which are more adapted to the change of industrial boilers than the primary ratio. The wind/coal ratio not only ensure the best combustion but also reduce the time lag and improve the system of quality control, which will transfer the amount of coal quickly and accurately to the wind loop through the feed-forward effect. The soft measurement technology can replace the actual measuring oxygen gas in a certain extent, This paper introduces the least-square method and the BP neural network algorithm and in previous studies, digest and absorb the basis, the gas oxygen soft measure model is respectively build by using the least-square solutions and the BP neural network through taking the historical data which come from the monitoring system of industrial boiler auxiliary variables (coal, wind, Smoke temperature, the steam flow, the steam pressure and temperature) as training samples. Compared with measured will be predicted, through comparative analysis of two kinds of models .It proved that the model by BP neural network model is higher estimating accuracy than the model by the least-square method and more accord with the actual requirement. |
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