CAT Titan 250 - Manual (Page 23)

Turbomachinery Package Specification Titan 250 Generator Set
• Fuel pilot control valve
• Fuel pilot manifold
• Inlet gas filter/coalescer loose shipped for field installation
Component Operation
The gas fuel pressure supplied to the turbine skid must meet minimum and maximum
pressure and flow requirements. If the gas fuel pressure is too high or too low, the control
system will prevent turbine operation. Pneumatically actuated primary and secondary gas
fuel shutoff valves are controlled using pilot air pressure. For each valve, pilot air
pressure is admitted to and exhausted from a pneumatic actuator through a solenoid
valve. Fail-safe operation ensures both valves will close in case pilot air pressure is lost.
The gas fuel control valves and the SoLoNOx fuel pilot control valve, are powered by
integrated DC motor-driven actuators. Integrated actuator electronics provide precise
closed-loop valve control based on position command inputs versus position feedback
outputs. The three valves are fast acting and provide fuel metering for light-off,
acceleration, full load, and load transient conditions. Fail-safe operation ensures both
valves will close in case the command signal or control power is lost. During the start
sequence prior to ignition, the control system will verify gas pressure and perform a gas
valve check to verify proper operation of all gas fuel valves.
Table 5. Fuel System Specifications
Gas Fuel System
Acceptable Gas Fuels See Note (a) Natural Gas
Propane
Butane
Fuel Quality Refer to Solar’s Engineering Specification ES 9-98
Compliance National Association of Corrosion Engineers
(NACE) Compliant
Minimum/Maximum Gas Fuel Supply Pressure 2240 to 3447 kPag (325 to 500 psig), See Note (b)
Minimum Flow Rate 3513 to 5480 kg/hr (7746 to 12086 lbm/hr), See
Note (b)
Minimum/Maximum Fuel Supply Temperature -40 to 93 °C (-40 to 200°F), See Note (c)
Primary Gas Fuel Shutoff Valve Pneumatically Actuated Spring-Closed Ball Valve
Secondary Gas Fuel Shutoff Valve Pneumatically Actuated Vane Type Valve
Gas Fuel Control Valve and SoLoNOx Fuel Pilot
Control Valve Actuator Valve
Actuator Voltage 120 VDC
Valve Discrete Signals 0 to 24 VDC
Valve Analog Signals 4 to 20 mA
Maximum Operating Pressure 4137 kPag (600 psig)
Maximum Operating Temperature 93°C (200°F)
Response Time Less Than 100 msec From 10-to-90% Stroke
Valve Body Aluminum (Standard)
Stainless Steel (Optional)
Gas Fuel Filter (Conventional Units Only) 10 Micron
Offskid Coalescing Filter Module (SoLoNOx Units
Only)
Maximum Operating Pressure 3447 kPag (500 psig)
Maximum Flow 122 m 3 /min (4300 ft 3 /min)
Minimum/Maximum Operating
Temperatures -29 to 100 °C (-20 to 212°F)
Filtration Efficiency β0.3 > 200 per ISO 4572
© 2008 Solar Turbines Incorporated. All rights reserved. TPS250GS/908 - Preliminary
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