GateCycle Software for Combined-Cycle Design and Thermal Performance

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GateCycle: Combined-Cycle Design and Thermal Performance Modeling Software

by GE Enter Software, LLC

GateCycle Background

GateCycle is an advanced, commercial power plant design, simulation and analysis program developed and supported by GE Enter Software. The program originally was developed by Enter Software, Inc. with early support from EPRI, the Electric Power Research Institute. The GateCycle program was first commercially released in 1988 and the EPRI funding support for GateCycle development ended in 1993. Since that time, GateCycle has been a fully self-supporting commercial software application with a large, active and growing user base. There are currently more than 400 active users of GateCycle at leading manufacturing and engineering companies around the world, including GE, ABB, Siemens-Westinghouse, Bechtel, Sargent & Lundy, Texaco, Shell, Southern Companies, Trigen and many others.

GateCycle is built upon a solid state-of-the-art software foundation. Its primary use is for the preliminary and engineering design of most types of conventional power plants, including simple-cycle gas turbine plants, combined-cycle and cogeneration plants, conventional fossil and fluidized-bed plants. GateCycle also includes advanced power plant engineering models which enable it to be applied to more advanced cycles, includes major portions of IGCC plants, advanced gas-turbine systems, and other advanced power plant concepts. GateCycle includes detailed design and off-design analysis routines in a single, integrated and consistent analysis framework, making it easy to apply the program through various stages of plant design and analysis such as advanced systems studies, preliminary screening analyses, initial conceptual design and detailed engineering design. GateCycle has been used to generate correction curves for acceptance test calculations and complex GateCycle models even been configured as part of a contractual on-line acceptance test calculator. With its flexibility and detailed off-design analysis capability, GateCycle can also be used to model existing plants to aid in off-line performance monitoring analyses, evaluating conversions and modifications, etc.

GateCycle is a Windows-based software program with an advanced graphical user interface system built partly around the PROVISION modeling environment licensed from Simulation Sciences (developers of an advanced process simulation software system for chemical processes known as PRO/II). The PROVISION library is used to provide the graphical model-building diagram and equipment data entry windows in GateCycle. The other interface elements in GateCycle (database functions, utility screens, plotting, Access reports, etc.) are developed primarily using Microsoft Foundation Class (MFC) software, including various third-party MFC libraries. GateCycle includes a simple but robust single-user database system. GateCycle is written in a mixture of FORTRAN and



C++: most of the engineering analysis routines remain in FORTRAN but most of the supporting database, interface and programming interface software is written in object-oriented C++. GateCycle is developed within the Microsoft Visual Studio environment, using Microsoft C++ and DEC Visual FORTRAN.

GateCycle runs on standard Microsoft Windows-based PC’s under Windows 95, Windows 98 or Windows NT (and is expected to run under Windows 2000). There are no special hardware requirements, although a fast Pentium-class PC (> 100 MHz) with reasonable RAM memory (> 32 MB) is recommended.

Features in Current GateCycle Addressing Current Power System Requirements

The current GateCycle features that satisfy current requirements for a combined-cycle thermal performance modeling package include:

• Underlying Software Architecture • Steam/Water Property Methods • Exhaust Gas Property Methods • Program Convergence Schemes • Error Handling • Hardware and Software Requirements • Model-Building GUI • Commercial Grade Installation, Support, Help, etc. • Basic Equipment Models • Core Functionality for External Program and Data I/O

The following paragraphs describe in more detail some of these key design elements and features in the current version of GateCycle.

Underlying Software Architecture

GateCycle is written using a modular, object-oriented software design approach. An object-oriented approach makes it easier to maintain the software, add new features and even restructure for new applications (such as web-based applications), particularly in a team programming environment. A modular design means that the core program modules (database, analysis, interface and primary application control) are relatively separate sets of code so that each can be maintained, updated or even replaced independently of the others with little impact on the end-user or the other modules.

Steam/Water Property Methods

GateCycle already includes most industry-standard steam/water property routines of interest, including the 1993 ASME formulations and the 1997 IAPWS (ASME) formulations.



Exhaust Gas Property Methods

GateCycle already includes several advanced gas property sets for primary exhaust-gas constituents, including JANAF and PTC formulations (for ideal gas) and some real gas property sets.

Program Convergence Schemes

GateCycle’s convergence scheme is independent of the power plant configuration. It is transparent to the user, but is based on a sequential-modular analysis structure where the flowsheet decomposition routines are built into the software. Although it has not proven to be necessary for any of the standard and advanced power plant cycles which have been studied with GateCycle so far, there are some advanced techniques and features which could be added to GateCycle’s convergence scheme to speed convergence in some situations or to aid in customization of the calculations. This will probably only be necessary when the GateCycle software architecture is extended to allow the inclusion of user-supplied equipment models (not just equations, but entire new icon models).

Error Handling

GateCycle already includes detailed error-logging utilities, which even automatically display error and logging messages in user-defined unit sets. Although currently adequate, GateCycle could be improved to more of the error-checking functions from the analysis module into the interface to allow more direct user interaction and even to eventually to provide automated model changes in response to some kinds of errors. This would be particularly useful for novice users.

Hardware and Software Requirements

As described above, GateCycle runs on standard MS Windows 32-bit PC’s with reasonable processor and memory requirements.

Model-Building GUI

With the PROVISION interface, GateCycle already offers an intuitive graphical model-building environment. However, the graphical output could be improved for customer reports, plots and diagrams.

Commercial-Grade Installation, Support, Help, etc.

Since GateCycle is a commercially offered software program, it includes commercial grade installation, help, tutorials, etc. and GE Enter Software offers phone/fax/e-mail support. GateCycle even includes a menu command to automatically e-mail entire models to other users or to the company for support questions.

Basic Equipment Models

GateCycle currently includes most of the core engineering models needed for basic combined-cycle and cogeneration plant design. The level of engineering detail is such that it is sufficient to enable GateCycle model to model plants at the design point with less than 0.5% error and less than 1% error over most normal off-design operating ranges.



Additional detail in the equipment models might be useful to extend the results to a sufficient level of detail for costing calculations at a detailed equipment and material level, or to reduce inaccuracies in more extreme off-design runs.

Core Functionality for External Program and Data I/O

GateCycle’s modular, object-oriented software design enables the core program functionality to be exposed to other standard Windows applications using Microsoft VB scripting. For example, the CycleLink Excel add-in utility is a simple VBA application developed for MS Excel that enables Excel users to access all GateCycle inputs and outputs directly from Excel spreadsheets and actually drive the GateCycle program (reading and writing to the database, running analysis, etc.). The same sets of functions used to develop the CycleLink utility are available to any Microsoft Visual Basic program, so GateCycle can already be easily linked to external programs and databases. In addition, the current version of GateCycle can generate Microsoft Access formatted report table files which could be linked to other programs easily.

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GateCycle Software for Combined-Cycle Design and Thermal Performance