Reduced Energy Cost through the Furnace Pressure Control in Power Plants
Maintaining pressure in the boiler’s furnace is one of the key requirements for proper combustion in steam boilers in thermal power plants. This paper proposes a control strategy that eliminates flap in the channel for the output gases. This is achieved by applying the frequency regulator for asynchronous motor speed control. Reference value for the frequency regulator is obtained through the PI controller. Special attention is given to tuning of PI controller. Well-tuned PI controller with the use of frequency regulator provides significant energy savings, because asynchronous motor for ventilator of steam boiler in thermal power plants has a large power. Modification of relay feedback experiment has supported λ-tuning of controller whose two types (faster and robust) were tuned. This modification consists in: a) Replacement of relay characteristic with saturation curve, b) Fourth-order process identification with first-order process plus dead time. The methodology is illustrated by simulations.
Energy saving, Combustion, Frequency regulator, PI controller, λ-tuning.