Investigations into the blockage of pulverized fuel pipes on coal-fired boilers using an electrostatic sensor system

Abstract

The blockage of pulverized fuel (PF) conveying pipes on a coal-fired power plant is a hazard accident. An in-depth understanding of the factors that cause PF pipe blockage provides operators with prior knowledge to avoid such accidents. Two representative primary air pipe blockage events are observed on two commercial boilers, respectively. The PF dynamic parameters of the two cases during the whole blockage processes are monitored by an electrostatic sensor array based instrumentation system. The variation trends of the velocity, mass flow rate, volumetric concentration and flow stability of PF particles in different blockage stages are described in detail. The main reasons for the two blockage events are analyzed based on the geometry of the PF conveying pipes and the dynamic parameters of the PF particles. The results obtained show that on-line monitoring of PF flow is an effective and reliable way for the early detection of PF pipe blockage.