CAPE-OPEN Integration for Advanced Process Engineering Co-Simulation

This paper highlights the use of the CAPE-OPEN (CO) standard interfaces in the Advanced Process Engineering Co-Simulator (APECS) developed at the National Energy Technology Laboratory (NETL). The APECS system uses the CO unit operation, thermodynamic, and reaction interfaces to provide its plug-and-play co-simulation capabilities, including the integration of process simulation with computational fluid dynamics (CFD) simulation. APECS also relies heavily on the use of a CO COM/CORBA bridge for running process/CFD co-simulations on multiple operating systems. For process optimization in the face of multiple and some time conflicting objectives, APECS offers stochastic modeling and multi-objective optimization capabilities developed to comply with the CO software standard. At NETL, system analysts are applying APECS to a wide variety of advanced power generation systems, ranging from small fuel cell systems to commercial-scale power plants including the coal-fired, gasification-based FutureGen power and hydrogen production plant. INTRODUCTION The Department of Energy’s (DOE’s) National Energy Technology Laboratory (NETL) is collaborating with its R&D technology partners to develop the Advanced Process Engineering Co-Simulator (APECS). APECS is as an integrated software suite that combines process simulation, high-fidelity computational fluid dynamics (CFD), immersive and interactive 3D plant walk-through virtual engineering, and advanced analysis capabilities for the improved design, operation, and optimization of process engineering systems (Zitney et al., 2006). For users in the process and energy industries, APECS offers process/CFD co-simulations that provide the necessary level of detail and accuracy required for engineers to analyze and optimize the coupled fluid flow, heat and mass transfer, and chemical reactions that drive overall plant performance and efficiency. At NETL, APECS facilitates for the first time the efficient and systematic integration of process simulation with CFD models of key power plant equipment items, such as combustors, gasifiers, syngas coolers, steam and gas turbines, heat recovery steam generators, and fuel cells. By coupling process/CFD co-simulations with advanced visualization and high-performance computing, APECS also offers opportunities for exploiting virtual plant simulation to reduce the time, cost, and technical risk of developing high-efficiency, zero-emission power plants such as the DOE’s FutureGen plant (Zitney, 2005a). In the APECS system, plug-and-play model interoperability is achieved by using the process industrystandard CAPE-OPEN (CO) interfaces (Osawe, 2005; Zitney, 2005b; Syamlal et al., 2004). The CO standard for process simulation was developed as an international collaborative among leading process industry companies, academic institutions, and software vendors (Braunschweig and Gani, 2002). The standard provides interfaces for process unit operations, physical properties, reaction kinetics, and numerical solvers. The interfaces are open, multi-platform, available free of charge, and supported by many of the leading commercial process simulators. Today the CAPE-OPEN Laboratories Network (CO-LaN, www.colan.org) is the internationally recognized, user-driven organization for the management, exploitation, and promotion of the CO standard. A recent review of industrial applications of the CO standard, including a brief discussion of the process/equipment co-simulation solution described here, can be found in Pons (2003). This paper describes the APECS integration framework for combining process simulation and CFD software using the CO interfaces. The application of APECS to process and fossil energy systems is also highlighted. APECS FEATURES AND CAPABILITIES The APECS integration framework uses the CAPE-OPEN (CO) software interfaces for unit operations, physical properties, and reaction kinetics. The methods of the CO unit operation interfaces enable the seamless use (e.g., Initialize, Edit, Calculate, Load, Save) of equipment models in the process flowsheet. The interfaces also facilitate the bi-directional exchange of stream information (flow rate, temperature, pressure, and compositions) between the process simulator and the equipment model. For CFD models, the multi-dimensional boundary conditions are mapped automatically to process streams and vice versa. The CO physical property interface is used to transfer constant or temperature-dependent physical properties (e.g., density, viscosity, heat capacity, thermal conductivity, molecular weight) from the process simulator to the equipment models. Similarly, the CO reaction kinetics interface facilitates the automatic transfer of reaction stoichiometry and power-law parameters from the process simulator to the equipment models. As shown in Figure 1, the hierarchy of unit operation/equipment models used by APECS ranges from high-fidelity CFD models to custom engineering models (CEMs) to fast reduced-order models (ROMs). The CFD models provide a detailed and accurate representation of a wide variety of process equipment items, while CEMs are typically engineering models that calculate mass and energy balances, phase and chemical equilibrium, and reaction kinetics. ROMs are a class of equipment models that are based on precomputed CFD solutions over a range of parameter values, but are much faster than CFD models. For example, the APECS system currently provides for automatically generating and using a ROM based on multiple linear regression to demonstrate the concept (Syamlal and Osawe, 2004). Future ROM solvers will include non-linear regression, neural networks (Osawe et al., 2006), and proper orthogonal decomposition. 2-3D Equipment Model Database Aspen Plus Process Model CFD Viewer CO Integration Controller (CAPE-OPEN Interface ) Configuration Wizard Reduced Order Model CO