Wenger 72944 Especificações descarregar pdf (Página 256)

Section 6 The Selected Alternative Plan

EAA Storage Reservoirs Revised Draft PIR and EIS February 2006

6-28

Engines now operate at 720 RPM, but speed can be increased as high as 900

RPM.

Although horsepower increases with RPM, the maximum normally aspirated

design output is 200 hp per cylinder, or 1600 hp at G-370 and 1800 hp at G-372.

Unless horsepower requirements can be reduced by changing the pump

discharge design, the only way to have enough horsepower is to turbo-charge the

engines at both pumping stations. Turbo-charging this type of engine allows 280

to 350 hp per cylinder to be produced. An engine turbo charging design should be

selected so the operational horsepower requirement is at least 50% of the rated

output. This means that in cases of low head differential between intake and

discharge, the flow might need to be restricted to create head and put enough

load on the engine.

Fairbanks-Morse (F-M) engines are capable of operating at 110% of the rated

output for a 2 hour overload period. F-M has verified that all F-M engines can

satisfy this requirement which is considered an industry standard.

Modified G-370 pump design as proposed by the pump manufacturer, Flowserve,

assumes a 10% increase in speed. Either changing the gear ratio or increasing

the engine speed could achieve this increase. Coordination with both F-M and

Philadelphia Gear will determine which change is more effective. The design of

the reduction gears, shafts, and power transmission components need to be

checked to see whether capable of handling the increased horsepower and

maintaining the recommended safety factor.

Engine modifications will require upgrades and changes in some auxiliaries. The

raw cooling water flow can likely be increased using the same pumps and

adjusting the orifices. The heat exchangers are believed to be the plate and

frame design, and it may be possible to merely extend their area and capacity.

The silencers may need to be upsized to handle the higher engine operational

level.

6.4.3.2.8 Backflow Prevention Modification Details

The original design of G-370 and G-372 used the control of a discharge chamber

as the only means of backflow prevention. However, the maximum EAA

reservoir depth of 12 feet makes it necessary to add both backflow control gates

and an arrangement for inserting stop logs or dewatering bulkheads. The

backflow gate and bulkhead system is needed to provide two means of backflow

prevention, a design requirement for cases when the pump discharge is located

below the discharge water maximum water level. A means for inserting stop

logs downstream of the backflow gates is needed to allow the backflow gates to

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Wenger 72944 Especificações Página 256