In the area of smart plant operations, AVESTAR’s dynamic simulators enable researchers to analyze plant-wide performance over a wide range of operating scenarios, including plant startup (cold, warm, hot), shutdown, fuel switchovers, on-load cycling, high-load operations of 90-120% of rated capacity, and high frequency megawatt changes for automatic generation control. The dynamic simulators also let researchers analyze the plant’s response to disturbances and malfunctions. The AVESTAR team is also using dynamic simulators to develop effective strategies for the operation and control of pre-combustion capture technology capable of removing at least 90% of the CO2 emissions. Achieving operational excellence can have significant impact on the extent and the rate at which commercial-scale capture processes will be scaled-up, deployed, and used in the years to come. If deployment of new CO2 capture technologies is to be accelerated, power generators must be confident in ensuring efficient, flexible, reliable, environmentally-friendly, and profitable plant operations.
AVESTAR’s dynamic simulators enable users to analyze capture process performance over a wide range of transient operations. Under carbon-constrained scenarios, power plants with CO2 capture will need to exploit variable operating strategies for capture facilities. AVESTAR’s IGCC simulator enables researchers to examine how adjusting CO2 emissions per unit of power generated impacts generation efficiency, cost, and net power output. AVESTAR’s dynamic simulators also let researchers ensure that the CO2 capture facilities do not impose serious restrictions on power plant controllability, flexibility, and emissions of other pollutants. CO2 capture processes must be able to recover smoothly from disturbances and move to new controller set points in a measured and timely manner. Potential disturbances include variable fuel input flow rates and compositions and fluctuating ambient conditions. Moreover, dynamic plant interactions, particularly heat integration issues, between CO2 capture and power generation processes must be considered. For improved profitability, effective control strategies are required to maintain plant operation close to economic constraints under conditions different than nominal design conditions, including varying rates of CO2 capture. In addition, the emission levels of other pollutants must be regulated in concert with the desired CO2 removal.
- Zitney, S.E. , Liese, E.A. , P. Mahapatra, R. Turton, and D. Bhattacharyya, “Accelerating Progress Toward Operational Excellence of Fossil Energy Plants with CO2 Capture,” AIChE 2012 Annual Meeting, Pittsburgh, PA, October 28 – November 2 (2012).
- Bhattacharyya, D. , R. Turton, and S.E. Zitney, “Dynamic Simulation and Load-Following Control of an IGCC power plant with CO2 Capture,” AIChE 2012 Annual Meeting, Pittsburgh, PA, October 28 – November 2 (2012).
- Zitney, S.E. , E.A. Liese, P. Mahapatra, R. Turton, D. Bhattacharyya, and G. Provost, "AVESTARTM Center: Dynamic Simulation-based Collaboration Toward Achieving Operational Excellence for IGCC Plants with Carbon Capture,” Proc. of the 29th Annual International Pittsburgh Coal Conference, Pittsburgh, PA, October 15-18 (2012).
- Provost, G.T. , M. McClintock, S.E. Zitney, Liese, E.A. , P. Mahapatra, R. Turton, and D. Bhattacharyya, “AVESTAR Center for Operational Excellence of IGCC Power Plants with CO2 Capture,” 2012 Gasification Technologies Conference, October 28-31, Washington D.C. (2012).
- Zitney, S.E. , E.A. Liese, P. Mahapatra, R. Turton, D. Bhattacharyya, and G. Provost “Advanced Virtual Energy Simulation, Training, and Research: IGCC with CO2 Capture Power Plant,” Proc. of the 28th Annual International Pittsburgh Coal Conference, Pittsburgh, PA, September 12-15 (2011).
Coal- and natural gas-fired power plants are experiencing increased stress as the demand for electricity from the grid fluctuates over time and as the use of variable renewable power generation (e.g. , wind, solar) grows more rapidly in the modern grid era. Many conventional fossil energy power plants were not designed to operate with large variations in power output, but must now cope with wide changes in power demand, often on an hourly basis. These frequent fluctuations in power output are referred to as “cycling” and “load-following” operation. These types of operation will accelerate equipment damage via thermo-mechanical fatigue, and will compromise plant performance, including pollutant controls, which were designed only to meet steady, base-load conditions. Using dynamic simulation, AVESTAR researchers can evaluate plant control and operation schemes without interrupting the physical plant. This can be especially useful in identifying unwanted plant responses during cycling and load-following operation.
- Zitney, S.E. , “AVESTAR Center for Innovation in Energy Plant Operations and Control,” Presented at the Fall NETL-Regional University Alliance Meeting on Energy & Innovation, Cannonsburg, PA, November 28-29 (2012).
- Zitney, S.E. , “AVESTAR Center for Smart Operation of Clean Energy Systems,” Smart Manufacturing Leadership Coalition (SMLC) Forum, Washington D.C. , October 2-3 (2012).
- Liese, E.A. , S.E. Zitney, P. Mahapatra, R. Turton, D. Bhattacharyya, and G. Provost, “AVESTAR Center for Operational Excellence of Clean Energy Plants,” 2012 Power Plant Simulation Conference (PowerPlantSim'12), San Diego, CA, February 12-17 (2012).
- Zitney, S.E. , “AVESTAR Center for Clean Energy Plant Operators of the Future,” Sixteenth Annual ARC World Industry Forum: Transforming Industry through New Processes and Technologies, Orlando, FL, February 6-9 (2012).
- Zitney, S.E. and R. Turton, “AVESTAR Center for Operational Excellence of Clean Energy Plants,” Presented at Invensys OpsManage’11, Nashville, TN, November 8-10 (2011).
For example, the results of a dynamic simulation using a prototype natural gas combined cycle (NGCC) power plant simulator at the AVESTAR Center show the temperature history of the turbine, the high-pressure superheater (HP/SH) steam temperatures (in, out), HP/SH temperatures (in and out) as well as the turbine flows. Simulation of plant dynamics can help identify strategies that reduce thermal cycling. For example, it could be possible to modulate the inlet guide vanes to reduce the thermal impact to the HRSG during load fluctuations– a control strategy which might not be normally employed because the control is designed to maximize steady-state efficiency. Scenarios like this can be explored rather quickly using AVESTAR’s dynamic simulators, allowing comparison of the efficacy of proposed changes long before implementation in a real power plant.
- Liese, E.A. and S.E. Zitney, “A Dynamic Process Model of a Natural Gas Combined Cycle – Model Development with Startup and Shutdown Simulations,” Proc. of the ASME 2013 Power Conference, Boston, MA, July 29 – August 1 (2013).