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Description / Abstract:
(a) This Appendix has been prepared to facilitate the calculation and
correction of turbine test
results by furnishing numerical examples of the procedures outlined in
The Performance Test Code on
Steam Turbines (PTC 6-1996). The feedwater heating cycles and gland
leakoff systems have been
simplified by avoiding unnecessarily long or repetitive calculations
while still demonstrating the
basic principles involved. Section 3 of this Appendix gives general
guidance for making these
calculations and comparisons to specified performance.
(b) Throughout this publication, the assumptions regarding turbine
performance and the numerical
values of corrections are hypothetical and should not be considered
applicable to any particular
unit.
(c) Except with written agreements to the contrary, the latest edition
of the ASME Steam Tables,
Thermodynamic and Transport Properties of Steam and its
enthalpy-entropy diagram (Mollier chart),
shall be used in the calculation of test results. When computers are
used, they may link to
compiled versions of the source code as supplied with the steam
tables. As of January 1999 a new
set of steam properties formulations, referred to as IAPWS IF-1997,
became the international
standard for calculations in the power industry. The IF-1997
formulations now supersede the
IFC-1967 formulations that were used for the preceding three decades.
Steam turbine performance tests based on heat balances utilizing the
IFC-1967 formulations, no
matter when conducted, must still use the IFC-1967 formulations.
The numerical examples in this document are based on the use of the
IFC-1967 formulations, as they
merely demonstrate a computational procedure. In actual tests, the
users must decide on the
formulations appropriate for their circumstances.
(d) It is ASME policy that "all works, papers, and periodicals
published by the Society shall
require units to be in the International System (SI)." In response to
that policy, all results are
shown in both units, and a calculation example of a complete expansion
condensing turbine is
provided in U.S. Customary units (Section 6) and SI units (Section
6a).
(e) Performance Test Code 6 on Steam Turbines (PTC 6-1996) is the
basic reference for this Appendix
and will be termed "the Code" in further references herein. Reference
should also be made to the
ASME Performance Test Code Supplements on Instruments and Apparatus
(PTC 19 Series) for guidance in
the selection, installation, and use of instrumentation.
(f) The numerical calculations shown in Sections 6 through 13 in this
Appendix have been computed
in sufficient detail to illustrate the technique involved. In many
instances, intermediate steps
that lead to the final answer have been included using assumed
guidelines for roundoff and number
of significant figures. The reader is cautioned that the use of
different guidelines or
computational procedures may result in slightly different values but
should have negligible effect
on the results of a test.