Simulation of Boiler Feed Pump Using Controller Program: A Case Study of Sapele Power Boiler Feed Pump

Abstract

The goal of this work is to automate the Sapele Power Plant Boiler Feed Pumps (BFPs) using CODESYS software to simulate BFP controlled by a proposed PLC system that was manually controlled. The boiler pressure, level, feed stream flow, and primary heat transport (PHT) pressure BFP were restored to their optimal levels within a few seconds after trip. This was possible for the standby program used for automation within 14 seconds when compared to the manual process that was in place. During the simulation, the BFP goes into standby mode after 14 seconds. The results obtained under automated condition shows the boiler pressure rises to 40.3 kg/cm-1s-2 and remained stable for 147 seconds as against 55.9 kg/cm-1s-2 in 25 seconds under unautomated conditions. The flow rate of the feed water shows a decrease of -0.172 m at 50 seconds. The boiler pressure rose further to 44 kg/cm-1s-2 at 175 seconds, which corresponds to a specific gravity value of 59.5 kg/cm3 at the same time. At 146 seconds, the feed water hits the trip setting of -2.85m owed to low specific gravity (SG) level when compared to the unautomated condition. Thus, a further increase reached fluctuation level of -10m at 200 seconds. The PHT was 88.5 kg/cm-1s-2 at 146 seconds contrary to the expected pressure of 105.6 kg/cm-1s-2 for unautomated state. This change after 146 seconds results from generator trip. The pressure increases to 90.2 kg/cm3 at approximately 148 seconds and subsequently decreases to 48 kg/cm3 consequently opening of the condenser steam discharge valve (CSDVs) and atmospheric steam discharge valve (ASDVs) during the simulation state.