GE94-02: Repair Flow Testing and Calibration Procedures for ...

such parts, without infringing existing patents. With infringement defined broadly, by one
attorney specializing in such issues, as, “the manufacturing, offering for sale, or selling any
product which includes the elements of even one claim made within a patent filing, is guilty of
infringing that patent.”
This paper attempts to, qualitatively, shed light on what steps must be taken by any entity,
which desires to reverse engineer, enhance engineer, or manufacture parts, which by be
patented. It is by no means a exhaustive dissertation on the subject, and can offer no hard and
fast guidelines in avoidance of infringement, rather this paper examines the patent process,
dissects some of the patents issued to either SWPC or GE, claim by claim, in an effort to offer
suggestions and guidelines for avoiding infringing the patents.
GEN21‐19: Combustion System Dynamic Monitoring. September 2002.
Monitoring combustion system dynamic pressure has, so far, been performed largely by the
Original Equipment Manufacturers (OEM), and primarily after modifying or changing the
combustion hardware, to ensure that the new hardware performs in accordance with OEM
requirements. However, as the user community becomes more comfortable with the
technology, and as they gain in knowledge and understanding of the advances turbine systems
and their inherent complexities, especially as it relates to dry combustion systems, what was
once considered “Black Art” and the realm of the OEM Engineering Specialist, is now beginning
to find acceptance as another weapon in the arsenal, in an attempt to control maintenance
cost.
All combustion processes, although for the purposes of this report we will concentrate on dry
NOX combustors, result in an inherent pressure release, called “thermoaccoustic” pressure. In
very basic terms, the combustion system pressure is directly proportional to the combustion
efficiency of a dry NOX combustor. By design, these combustors are intended to burn a
homogenous, or completely pre‐mixed fuel and air mixture, at a fuel lean ratio, or one in which
there is less than the stoichiometric, or ideal, fuel to air ratio. However, due to inefficient
mixing, local “pockets” of diffusion mode flame may be present, which will demonstrate a
higher combustion pressure than the pre‐mixed flame. By monitoring these pressure pulses,
the O&M Professional can gain insight into the health of the combustion system. Some of the
problems, which can be detected through the proper application and use of one of these
systems, are shown below:
� Combustion system hardware incipient failure
� Fuel control valve calibration
� Fuel nozzle pluggage/bypass