The Research Of Steam Boiler Combustion Process Of Piecewise PID Control

With the change of the housing condition, central heating has been becoming common heatingsystem. Boiler acts the main heating facility, so it must be reasonable control mode design that notonly ensuring the heating quality but also ensuring that environmental and economic combustion.Chain boiler is the main coal-fired heating. It is still inadequate that the combustion efficiency is stillrelatively low. In this case, it is necessary that boiler combustion should be studied and controlsystem is designed.In this paper, through Lao shi dan coal heating boiler project of Wuhai energy companysupporting, we design a set ofreasonable controlsystemafter a fullunder-standing ofthe process ofsteam boiler. The complexity of the boiler combustion control is divided into three parts: control ofdrum level control, furnace pressure control, combustion efficiency ofcontrol namely the ratio ofairand coal. This article analyzes the reason of the false water level. In the part of burning efficiency,the relationship between thethermal efficiency of the furnace and the air supply volume is analyzed.The ratio ofair and coalself-optimizing controlalgorithm is proposed.Although a common PID regulation is widely used in practical engineering projects and therelative stability of the control system and to a certain extent eliminating steady state error, it is easyto overshoot. It is harmful for the boiler control system, especially for closed boiler drum. Once theovershoot is difficult to make the liquid level to the set value. The control performances of singlePID controlsystemto a boiler heating systemare not ideal, either overshoot or controltime too long.The fuzzy PID control in PLC is difficult to achieve. Piecewise PID can restrain the overshoot as akind of easy achieve, so this paper uses this method to carry on the control to the boiler combustionprocess.In this paper, the PC, PLC and electrical equipments, instruments and sensors are electricallyconnected components of boiler combustion control system. The host computer is used for theWincc configuration screen to real-time monitoring for the boiler control system. PLC and the hostcomputer connecting ensure operation of real-time information to transmit boiler configuration screen display. At the same time, the operator commands are ordered control the operation of boilerauxiliary equipment. Instruments and sensors realize data acquisition, transmission and display andso on.