Pratik Pednekar

Modeling and Simulation of Components in an Integrated Gasification Combined Cycle Plant for Developing Sensor Networks to Detect Faults

The goal of this work is to help synthesize a sensor network to detect and diagnose faults and to monitor conditions of the key equipment items. The desired algorithm for sensor network design would provide information about the number, type and location of sensors that should be deployed for fault diagnosis and condition monitoring of a plant. In this work, the focus was on the integrated gasification combined cycle (IGCC) power plant where the faults at the equipment level and the plant level are considered separately. For component level sensor placement, high-fidelity partial differential algebraic equation (PDAE)-based models are developed. In this work, the sour water gas shift reactor (SWGSR) and the gasifier are considered at the unit level. A MATLAB-based PDAE model of the SWGSR has been developed that considers key faults such as changes in the porosity, surface area, and catalyst activity. For capturing the slag formation, and detachment phenomena accurately, a novel hybrid shrinking core-shrinking particle (HSCSP) model is developed. For tracking the detached slag droplets and the char particles along the gasifier, a particle model is developed and integrated with the HSCSP model. A slag model is developed that captures the process of the detachment of the slag droplets from the char surface, transport of the droplets towards the wall, deposition of a fraction of the droplets on the wall and formation of a slag layer on the wall. Finally, a refractory degradation model is developed for calculating the penetration of the slag inside the wall and the size and time for a spall to occur due to the combined effects of volume change as a result of slag penetration as well as thermal and mechanical stresses. Sensor placement using a "two-tier" approach is also performed by developing a sensor network for a combined system that includes unit level as well as system level faults. A model of the gasification island is developed by integrating the SWGSR model developed in MATLAB with the model of the rest of the plant developed in Aspen Plus Dynamics. Since the two models are developed using different software platforms, an integration framework is developed that couples and synchronizes the two dynamic models. The sensor network obtained using the models developed in this work is found to be effective in observing and resolving faults both at the unit level as well as the plant level. 

• Pednekar P, Bhattacharyya D, Turton R, Rengaswamy R, “Dynamic Model of a Slagging Entrained-Flow Gasifier Including Models of Slag Transport, Deposition, and Slag Layer”, Industrial and Engineering Chemistry Research, 55, 279-292, 2016 

• Pednekar P, Bhattacharyya D, Turton R, Rengaswamy R, “Development of a Hybrid Shrinking-Core Shrinking-Particle Model for Entrained Flow Gasifiers”, AICHE Journal, 62, 3, 659-669, 2016

• Pednekar P, Bhattacharyya D, Turton R, Rengaswamy R, “Development of a Slag Submodel for an Entrained-Flow Gasifier,” Proc. of the 29th Annual International Pittsburgh Coal Conference, Pittsburgh, PA, October 15-18 (2012)

• Pednekar P, Bhattacharyya D, Turton R, Rengaswamy R, “Modeling Slag Deposition and Refractory Degradation in an Entrained-Flow Gasifier”, Paper 186c, AIChE Annual Meeting, Atlanta, GA, November 16-21, 2014

• Pednekar P, Bhattacharyya D, Turton R, Rengaswamy R,  “Modeling Refractory Degradation in an Entrained-Flow Gasifier”, 57th Annual ISA Power Industry Division Symposium, Scottsdale, AZ, June 2-4, 2014

• Rengaswamy R, Mobed P, Maddala J, Bhattacharyya D, Turton R, Pednekar P, “Model-Based Sensor Placement for Component Condition Monitoring and Fault Diagnosis in Fossil Energy Systems,” 2014 National Energy Technology Laboratory Crosscutting Research Review Meeting, Pittsburgh, PA, May 19-23, 2014

• Pednekar P, Bhattacharyya D, Turton R, Rengaswamy R, “Modeling Refractory Degradation Due to Slag Penetration in an Entrained-Flow Gasifier”, Paper 122g, AIChE Annual Meeting, San Francisco, CA, November 3-8, 2013

• Pednekar P, Bhattacharyya D, Turton R, Rengaswamy R, “Dynamic modeling of detachment, transport, and flow of slag in an entrained-flow gasifier,” Paper 529g, AIChE Annual Meeting, Pittsburgh, PA, October 28- November 2, 2012

• Pednekar P, Bhattacharyya D, Turton R, Rengaswamy R, “Development of a slag submodel for an entrained-flow gasifier,” Session 27 Gasification: General-4, 29th Annual International Pittsburgh Coal Conference, Pittsburgh, PA, October 15-18, 2012