Title: Model predictive control for an industrial coal pulveriser

Authors: Vini Dadiala; Jignesh Patel; Jayesh Barve

Addresses: Department of Instrumentation and Control, Institute of Technology, Nirma University, Sarkhej – Gandhinagar Highway, Gota, Ahmedabad, Gujarat-382481, India ' Department of Instrumentation and Control, Institute of Technology, Nirma University, Sarkhej – Gandhinagar Highway, Gota, Ahmedabad, Gujarat-382481, India ' GE Global Research, GE India Technology Center, Whitefield Road, Bengaluru, Karnataka-560066, India

Abstract: The coal-pulveriser/coal-mill is an important subsystem upstream of boilers in coal-based thermal power plants. The efficient boiler operations demand optimum combustion-air to coal-fuel ratio (AFR). In fact, portion of (preheated) combustion-air called primary-air, passes through coal-mill and carries pulverised coal to the boiler. The safe, efficient coal-mill operation is important and requires - safe temperature control of primary air-coal mixture inside/outlet of mill; optimum primary air-to-fuel ratio (pAFR); and swift tracking of coal-flowrate setpoints to cater for variable power-load demands. In this paper, a multivariable Model Predictive Control (MPC) scheme is proposed for specific industrial coal-mill. Also, simulation study is performed using validated industrial coal-mill model, and performance of MPC is compared with two other control schemes - industrial 2PI, and prior published 3PI with selective control. The MPC outperforms the other two control schemes and provides better control performance; well-respects coal-mill operational constraints; and improves pAFR.

Keywords: coal pulveriser; AFR; air-fuel ratio; model predictive control; pAFR; primary air-fuel ratio; stochiometric AFR; 3PI with selective control; coal moisture; latent heat; sensible heat.

DOI: 10.1504/IJMIC.2020.117491

International Journal of Modelling, Identification and Control, 2020 Vol.36 No.4, pp.353 - 362

Received: 31 Aug 2020
Accepted: 27 Oct 2020
Published online: 09 Sep 2021 *

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