| Abstract [eng] |
The final project of the master studies describes the adaptive flue gas control system of PTVM-100 boiler, which should increase the boiler efficiency factor and power by 1.5–2% allowing to achieve safe boiler operation and reduce emissions (NOx, CO, etc.) The work presents the imitation model of the flue gas control system – a pneumatic system simulating the exchange of the flue gas pressure and flows with the change of the throughput of the draught channel (louvre opening degree), chimney draught and flue gas pressure in the flame zone. The model evaluates the geometric, mechanical, and aerodynamic parameters of the boiler and the draught channel, as well as the changes of the flue gas temperature in the system. The model reliably simulates the flue gas transfer process in the draught system, which cannot be obtained experimentally. Based on the simulation model structure and the calculated parameters, six linear dynamic models of the draught system were prepared. By means of computer-based simulation, reaction curve families (in terms of all input variables for each combination of operating burners) were obtained. After performing the analysis of the draught control system and its potential structures, the following structure control system was selected for the research: single loop control system with the standard PI regulator, and adaptive control system with PI regulator, with parameters being continuously adjusted according to the changing burners and the supplied flue gas flow. Regulators of both systems have been tuned according to ITAE criterion. Quality benchmarks of the developed control systems (in terms of the main disturbances affecting the draught system – chimney draught and the resulting flue gas pressure) were obtained by mathematical modeling, and compared with each other. The program was developed for the adaptive PI regulator with stepwise correction of tuning parameters in the programmable logical controller (PLC). The control quality benchmarks when the draught process is controlled by the PI regulator having the stepwise adjustment parameter correction were obtained and evaluated by means of simulation. The results of the research allowed to conclude that the adaptive PI regulator with both continuous and stepwise correction of tuning parameters can be used for flue gas control of the PTVM-100 boiler. |
