Advanced Process System in Cement production
Customer: Denizli Cimento (OYAK GROUP) (http://www.denizlicimento.com.tr/)
In 2019, an agreement was signed between PROSTO and Denizli Cimento (DC). According to the contract PROSTO specialists with DC specialists have to work on the modernization of the expert system to achieve better of Kiln control.
Documentation for the expert system, as well as program settings, was provided as initial data. The main and most difficult task for the PROSTO company was to determine what Modelinig Predictive Control (MPC) responsible for in the overall control scheme of the firing process in the factory and is it good or not enough.
Close cooperation with factory specialists helped to better understand the features of the process and the design of the current control system.
It was defined that MPC largely works on large time frames and its main task is to find the optimal equilibrium state of the system through solving a set of mathematical equations in a given range.
According to the theory and practice of numerical methods of solving such problems with incorrectly set parameters and coefficients, the system may not find an equilibrium state and will work in non-optimal modes; when the MPC program is launched, the expert system goes on the range boundaries and does not produce the necessary control. Also it was written that at least PID should control the process and MPC intended for manage PID setpoints, but in DC project was no any PID up to now.
It was also defined the lack of logic for controlling fast processes, such as maintaining temperature on cyclones, the logic of maintaining the kiln current setpoint by setting the rotation speed and material feed.
The logic of compensating drops down of alternative fuel was not fully implemented. A faster reaction was required to change the rotational speed of the kiln. The main drawback of the Pavillion expert system was that it could not work in an unstable mode and could not straighten out the technological process.
PROSTO company experts proposed standard steps that allowed the kiln to remain stable, solved the problem of “fast” control of fuel supply to maintain temperatures, and also developed in close cooperation with technologists special algorithms that allow optimization of costs (electricity and fuel consumption) by automatically adjusting the set points.
Also special SCADA page was developed to provide better way of controlling the process by means in case of using expert system.
Thus, the developed control algorithms made it possible to control the technological process in automatic mode, and the task of the operators is to monitor the state of the technological process, in case of emergency, transfer the control to manual mode.
At present, the process is being watched by production staff, operators of various shifts monitor the system and issue necessary comments on the system.
The advantage of the newly created system is that the whole control logic is clearly defined for each state of the process. The impact of expert system is the same, unlike different operators manner of control the system. Constant and predictable control provide stability of the process.