Gas Turbine Handbook : Principles and Practices

236 Gas Turbine Handbook: Principles and Practices
closed unloading station and transferred to a coal storage dome.
The unloading station will consist of two receiving hoppers, each
equipped with a vibrating-type unloading feeder that will feed the
raw coal conveyor systems. All material handling systems will be
enclosed and supplied with dust collection systems for environmental
control.
The steam turbine will be a straight condensing unit with an
uncontrolled extraction and an uncontrolled admission. The guaranteed
rating is 46226 kW, with the VWO expected output of 50785
kW. The steam conditions are 950 psia [65.5 Bars], 950°F [510°C]
inlet, with exhaust at 0.98 psia [67mBars]. At the rating, the
uncontrolled extraction pressure is 485 psia [33.4Bars], and the
uncontrolled admission is 54 psia [3.7Bars]. The turbine will have
26 inch [0.66m] last stage buckets in an axial exhaust configuration.
The turbine will be fully packaged, baseplate mounted, with
a combined lubrication and control system mounted on a separate
console. The control will be a GE Mark V Simplex system. The
generator is a fully packaged and baseplate mounted GE TEWAC
unit rated at 59000 KVA at 0.85 power factor.
The gas turbine is a General Electric MS6001FA. It is an
evolutionary design, being aerodynamically scaled from the larger
MS7001FA machine. It shares the same thermodynamic cycle with
previous GE “F”-class machines. Key characteristics of the “FA”
cycle pertinent to the Sierra Pacific application are the 2350°F
[1288°C] firing temperature and high output for this frame size, elevated
exhaust temperature making possible high combined cycle
efficiencies and the ability of the combustion system to burn a wide
spectrum of fuels.
The MS6001FA has a compressor or “cold-end” drive flange,
turning an open-ventilated GE 7A6 generator (82000 KVA @
0.85PF) through a reduction load gear. The exhaust is an axial
design directing the gas flow into the HRSG. These mechanical
features have facilitated an optimum plant arrangement for Sierra
Pacific’s combined cycle heat recovery application.
Plant Performance
Key aspects of the predicted plant performance are summarized
in the tables opposite.