Appendix E-2.c.i Energy Plan 2004-2013 Follow-up Studies and ...

Re-powering Study for the Northport and Port Jefferson Power Stations
Appendix II Northport System Descriptions
total of 42 cells. The cells are in a “butterfly” arrangement with four streets on one side of the main
exhaust header and three streets on the opposite side.
Noncondensables are extracted from the steam by a hogging vacuum pump and a continuous holding
ejector. During startup, the hogging pump removes air from inside the steam ducts, steam manifolds and
bundles. It reduces the air pressure within the system from atmospheric to about 10 in. Hg absolute in a
time period usually not to exceed 30 minutes..
The condensate storage tank will be sized for a 10 minute operating storage capacity. The total tank size
will exceed the operating storage capacity by an amount equal to the total condensate held in the drain
pots and drain piping.
The steam duct system will connect the condenser inlet-steam manifold to the turbine exhaust flange. It
includes expansion joints, anchor points, elbows, turning vanes and duct supports.
Instrumentation includes temperature indicators and thermocouples; pressure indicators and transducers;
vibration-pickup transducers; liquid-level devices; status lights; annunciator panel; and recorders. The
controls will also control storage-tank condensate level; fan pitch control; air louver control; steam-valve
control; and fan-motor control. These controls will be designed to minimize auxiliary-fan power
consumption, and protect the condenser from freezing.
In the event of complete electric-power failure to the steam-condenser fans, an atmospheric-relief
diaphragm safety device is installed in the turbine exhaust system, to protect the turbine exhaust hood
from excessive steam pressure. A steam-bypass system is provided which exhausts attemperated main
steam directly into the cold reheat line during startup.
2.7 Condensate
Refer to PID-04-01A and 04-01B in Appendix III.
The Condensate System for Northport has two 100 percent condensate pumps. The second condensate
pump is started for steam turbine bypass operation.
The 100 percent capacity vertical turbine-type centrifugal condensate pumps, set in suction cans, take
suction from the condensate storage tank through individual suction lines and storage tank connections.
The Condensate System supplies condensate to both electric and steam air ejectors, gland steam
condenser, LP economizers of each HRSG, the auxiliary steam desuperheater, hot reheat and LP steam
bypass valves, turbine exhaust hood spray, and condenser curtain spray, as well as water for HRSG IP and
HP drum fill and closed cooling water system make-up. The Condensate System is capable of continuous
operation for flow rates ranging from minimum recirculation to 100 percent of design capacity.
Each pump suction line contains a butterfly isolation valve, a basket strainer, a relief valve and an
expansion joint at the pump suction connection. The basket strainer is supplied with a coarse mesh
element for normal plant operation and a fine mesh element for flushing and start-up. Pressure differential
indication is provided for each strainer in the distributed control system (DCS).
Each pump discharge line contains a local pressure gage, check valve, butterfly isolation valve, and slipstream
for pump seal water. Each pump is vented by individual lines to the condensate storage tank.
A recirculation valve provides condensate pump minimum flow protection and maintains the required
minimum flow through the gland steam condenser. Recirculation water is returned to the condensate
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