Process Engineering Equipment Handbook 2009 Part 10 pdf

Solids removal efficiency: 100 percent for particles of 8 microns and larger, 99 percent for particles of 6 to 8 microns, 90 percent for particles of 4 to 6 microns, and 85 percent for particles of 2 to 4 microns. See Fig. F-32. Vertical absolute separators Definition: Vertical single or two-stage separator for removal of solids and very fine mists with liquid removal efficiency of 100 percent for particles 3 microns and larger, and 99.98 percent for particles less than 3 microns. Solids removal efficiency: 100 percent for particles of 3 microns and larger, and 99.5 percent for particles of 0.5 to 3 microns. Line separators Definition: Vertical vane-type separator with liquid removal efficiency of 100 percent for removal of particles 10 microns and larger. Fuel Systems; Fuel Flow Control One* of the most common types of fuel flow control is electrohydraulic control. There are electrohydraulic control solutions for differing environments, including low- pressure and potentially explosive conditions. Fuel Systems; Fuel Flow Control F-29 FIG. F-32 System installed in Saudi Arabia includes one vertical dry scrubber followed by two pressure regulating valves and a line separator. A condensate drain tank is mounted alongside. (Source: Peerless.) *Source: J.M. Voith GmbH, Germany. Adapted with permission. Modern industrial gas turbine systems require precise fuel dosage for the lowest possible NO x emissions. Each application requires the right actuator and valve combination to achieve exact, uniform fuel distribution to the burner. See Figs. F- 33 and F-34. The controller needs to be: 1. Inherently reliable (robust construction and low-pressure hydraulics) 2. Equipped with single-stage signal conversion which results in fast, accurate response times 3. Equipped with an oscillating magnet and minimized bearing forces to avoid static friction effects 4. Easy to install because the magnet and control electronics are all one unit 5. A control with availability of 99.9 percent The actuator is only one of the components necessary for accurate flow control. Some controls OEMs cooperate with leading valve manufacturers to offer a total control system. All valves and actuators are factory mounted and aligned to reduce labor- intensive adjustments during commissioning. Balanced valves have low force demands. Trip time of the complete valve assembly is less than 200 ms and the related increase in pressure is absorbed by the valve. Valves are available with soft seals as well as with bellows for gaseous fuels. For optimum performance and safety, electrical components face a burn test operated under “cold” conditions. (See Figs. F-35 and F-36.) Electrohydraulic actuators utilize an integrated position regulator that provides a true position signal. Other assembly features generally provided by actuator OEMs include: 1. Minimal interfaces 2. Valves designed to run without additional breakaway thrust, even after long, continuous operation 3. Flange mounting for easy assembly F-30 Fuel Systems; Fuel Flow Control FIG. F-33 Electrohydraulic actuator in a U.S. power station. (Source: J.M. Voith GmbH.) FIG. F-34 Section through an electrohydraulic actuator. Main components: 1, DC control magnet with integrated control electronics; 2, control piston; 3, position sensor; 4, clamp magnet; 5, drive piston; 6, piston rod; 7, stem; 8, stuffing box packing; 9, body; 10, trim; 11, fuel inlet; 12, seat. (Source: J.M. Voith GmbH.) F-31 4. Fail-safe design 5. Explosion-proof design 6. Controlled emergency trip 7. Ease of commissioning and installation 8. Low maintenance 9. Compact design F-32 Fuel Systems; Fuel Flow Control FIG. F-35 Schematic of gas turbine fuel system. ᭿ – ᭝ ᭞ = control valve assembly, G = generator, T = gas turbine. (Source: J.M. Voith, GmbH.) FIG. F-36 Functional schematic of control valve assembly. X 0 = pressure P A at I = 0 or 4 mA; X 1 = pressure P A at I = 20 mA; K p = proportional amplification; F M = magnetic signal/force; F 1 = feedback force/signal to controller; F A = hydraulic cylinder force. (Source: J.M. Voith, GmbH.) 10. Inherent long-life design 11. Failure indication signal 12. Insensitive to dirt due to encapsulated design 13. Control and performance insensitive to temperature 14. Precise repetition 15. Fast, hysteresis-free processing of signal 16. Friction free due to oscillating solenoid force 17. Compensation of different expansion factors with internal position regulator 18. Not affected by disturbance factors such as air gap, magnetic hysteresis, and voltage fluctuations 19. Open loop control, PID configuration Typical range of valve actuators for gas turbines* Control, emergency trip, and relief valves can be equipped with electrohydraulic actuators: Medium Nominal Widths Nominal Pressure Stages Natural gas Up to 200 mm (8 in) Up to 63 bar (914 psig) Diesel oil Up to 100 mm (4 in) Up to 160 bar (2320 psig) Water Up to 100 mm (4 in) Up to 160 bar (2320 psig) Performance parameters: ᭿ Maximum flow rate of gas valves: 450 m 3 /h (1982 GPM) ᭿ Maximum flow rate of oil/water valves: 160 m 3 /h (705 GPM) ᭿ Design of the valves to: ANSI or DIN specifications ᭿ Internal fittings: Perforated or solid cone ᭿ Flow curve characteristics: Linear, same percentage, open-closed, or specific ᭿ Installation: Flanges or welded ends ᭿ Valve tightness: Up to 0.001% of nominal K VS value Actuators* Performance features include: ᭿ Standard actuator stroke 50 mm (2 in) to maximum stroke 200 mm (8 in) ᭿ Explosion-proof design is standard ᭿ Operation with hydraulic or pneumatic auxiliary energy ᭿ Low- and high-pressure designs up to 170 bar (2,500 psig) available ᭿ Accuracy: ±0.1 mm absolute ᭿ Tripping force at a stroke of 0 percent: ≥15.000 N Fuel Systems; Fuel Flow Control F-33 *Source: J.M. Voith GmbH, Germany. Adapted with permission. ᭿ Hydraulic force: ≥41.000 N ᭿ Opening time: ≥200 ms ᭿ Tripping time: £150 ms ᭿ Operation with negligible hysteresis: Resolution <20 mm ᭿ Availability: >99.9 percent ᭿ MTBF: >5 · 10 6 ᭿ Service life: >2 · 10 6 Fuel Skid Fuel systems, whether part of a turbomachinery system or otherwise, generally consist of a skid to hold the main components, piping, control valves, and metering valves. The illustration of a fuel system skid in Fig. F-37 is typical of a skid that is supplied with a turbomachinery package. Typical valves in the system are indicated in Fig. F-38; they perform metering, isolation (shutoff), or staging functions. Figure F-39 illustrates a typical hydraulic-actuated modulating sleeve valve. Note the mechanical feedback on this valve type. Figure F-40 illustrates a servo motor actuated plug metering valve and its performance parameters. F-34 Fuel Systems; Fuel Flow Control FIG. F-37 Universal all-electric DLE and SACn gas test cell fuel skid used with LM engines. (DLE and SACn are Whittaker model designations; LM refers to GE LM series gas turbines.) Approved to CSA, Ex standards. (Source: Whittaker Controls.) FIG. F-38 Some typical fuel system components. (Source: Whittaker Controls.) Fuel Systems; Fuel Flow Control F-35 FIG. F-39 Typical 3-in hydraulic actuated modulating sleeve valve. (Source: Whittaker Controls.) F-36 Fuel Systems; Fuel Flow Control FIG. F-40 Typical 2-in servo motor actuated plug metering valve. (Source: Whittaker Controls.) OPERATING FLUID: Natural gas APPLICATION: Aeroderivative TEMPERATURE: Ambient: -65 °F to 350 °F Fluid: 32 °F to 400 °F ELECTRICAL: Motor Voltage: 170 VDC servo motor Current: 0.3 amp max steady state Resolver Voltage: 4 VAC Current: 25 to 60 ma max Position switch Voltage: 28 VDC Current: 2.5 amp Connector: Terminal block INSTALLATION DATA: Flanges: Per ANSI B16.5, 1.5 inch pipe, Class 600 both ends WEIGHT: 80 lb max PERFORMANCE: Flow: 0 to 4.0 lb/sec, in direction shown effective area linearly propertional to valve stroke. Accuracy ±1% from 1.0 to 4.0 lb/sec Pressure: Operating: 100 to 600 psig Proof: 1,440 psig DP: 15 psid at 4 lb/sec, 500 psig at 60 °F Hydrostatic: 2,160 psig at room temperature Leakage: Internal: ANSI class IV Operating time: Open to closed: 100 msec max Closed to open: 100 msec max Fail safe closed: 500 msec max *Source: Whittaker Controls, USA. Adapted with permission. Fuel System Testing Part of a typical test routine is outlined here. The end user concerned about fuel system malfunction needs to question the supplier, often a subvendor, about the results of some of these tests. Typically, the OEM adds its own nameplate to the system provided by the subvendor. Typical fuel systems test specification* (for dual fuel machines or DLE systems) A typical test specification would call for performance of the following tests: ᭿ Fuel pressure cycle testing (DAT) ᭿ Performance ᭿ Endurance ᭿ Burst ᭿ Surge ᭿ Fire resistance ᭿ Leakage (internal) ᭿ Leakage (external) Expected results vary based on line size. For instance, typical nominal test capabilities for a 3-in line size cover three ranges. 1. Static bench test for leakage (100 gpm at 1300 psig) 2. Self-contained dynamic test (low flow) (150 gpm at 600 psig) 3. Self-contained dynamic test (high flow) (300 gpm at 1300 psig and 1800 gpm at 600 psig) Fuels, Alternative; Fuels, Gas Turbine* The term fuel in process engineering generally means fossil fuel. The most common fossil fuels in use today are natural gas, oil, and coal. The latter two have many varying grades and sulfur contents. The emissions evolved from combustion of the fossil fuels are dealt with under other subject headings in this book, including Emissions and Turbines. Common Gas Turbine Fuels In broad terms, gas turbine fuels can be classified as gaseous or liquid fuels. The terms “gaseous” and “liquid” indicate the state of the fuel as it enters the gas turbine and not the state it is stored in at the site. The most commonly encountered gaseous fuels include: ᭿ Natural gas ᭿ LNG (liquefied natural gas) ᭿ LPG (liquefied petroleum gas; typically a blend of propane and butane) ᭿ Refinery gas ᭿ Blast furnace gas ᭿ Coke oven gas ᭿ Coal gas ᭿ Hydrogen Suitable liquid fuels include: ᭿ Distillate No. 2 (diesel fuel) ᭿ Kerosene (K-1) ᭿ Jet A ᭿ Naphtha ᭿ Condensate fuels ᭿ Methanol (CH 3 OH) ᭿ Ethanol (C 2 H 5 OH) ᭿ Crude oil ᭿ Heavy fuel oil Fuels, Alternative; Fuels, Gas Turbine F-37 *Source: Adapted from extracts from Narula, “Alternative Fuels for Gas Turbine Plants—An Engineering, Procurement, and Construction Contractor’s Perspective,” ASME paper 98-GT-122. [...]... LPG is a by-product of natural gas treating processes or an incidental gas recovered during the oil extraction process It generally comprises propane, butane, or a combination of both As the spot market price for propane and butane varies with the seasonal demand, the receiving terminal and power plant facilities must be designed to handle 100 percent propane, 100 percent butane, or any combination of... (typical blend) Propane Butane Refinery gas Blast furnace gas Coke oven gas Hydrogen 35.5 (900) 35.5 (900) 104 .8 (2,700) 91.2 (2,300) 118.5 (3,000) Varies 3.6 (90) 11.8 (300) 10. 8 (270) Comments* (1), (2), (2), (2), (2), (7) (7), (7), (9), (2), (4) (3), (6) (3), (5) (5) (5) (8), (17) (11), (14), (16) (10) , (16) * Refer to comments nomenclature below Table F-9 TABLE F-9 Liquid Fuels for Gas Turbines Fuel... adjacent equipment ᭿ Gas dispersion analysis—Determines the dispersion of vaporized LNG for various climatic conditions The extent of a vapor cloud is used in determining the minimum distance to sources of possible ignition ᭿ Detonation analysis—Addresses the resultant blast from unconfined or confined vapor explosions This determines blast protection requirements and the safe distance for structures and equipment. .. even the once-stranded gas fields are turning out to be economically viable sources of fuel supply From the source the gas is piped to a coastal location where it is processed to remove impurities and inerts After extracting heavy ends, the processed gas is finally refrigerated to make LNG and stored at atmospheric pressure and at a temperature of approximately -160°C (-256°F) After the LNG is loaded into... respectively The LPG tankers are generally smaller (80,000 m3) and less expensive than LNG tankers The higher boiling temperatures of these gases (relative to LNG) and the owner’s desire to use 100 percent propane, 100 percent butane, or a mixture of both has a significant impact on the size and design of the refrigeration system for storage tanks as well as on the design of the vaporization facility It... Power Transmission) Reference and Additional Reading 1 Bloch, H., and Soares, C M., Process Plant Machinery, 2d ed., Butterworth-Heinemann, 1998 Gears (see Power Transmission) Generators; Turbogenerators* This section is written with reference to specific models made by the Alstom corporation Most generator original equipment manufacturers (OEMs) use similiar standards Standard Design The modular design... quantities of other pollution Arrangement Forms The machines can be supplied in the following versions: Arrangement Forms Descriptions IM 100 5 Horizontal shaft, two bearings mounted in the bearing end shields, one free shaft extension end with coupling flange IM 100 7 Horizontal shaft, two bearings mounted in the bearing end shields, two free shaft extensions with one coupling flange This version permits... Turbogenerators FIG G-9 G-13 Cooling air direction (Source: Alstom.) FIG G -10 Closed cooling system (Source: Alstom.) Rotating rectifier The purpose of the rectifier is to rectify the AC current from the main exciter and provide the rotor winding of the turbogenerator with DC current via connectors in the center of the shaft The electrical equipment in the rectifier consists of silicon diodes and RC protection... bracket is provided with a brush holder pocket for connection of a handle to hold two carbon brushes The carbon brushes in the handle parts are mounted in holders of coil-spring type that give a constant brush pressure during the service life of the brush The handle parts are insulated and the brush holders can be removed from the brush holder pockets by hand when the brushes are to be replaced Brush... more extensive test can be offered separately Control and Protection Temperature monitoring A number of platinum wire resistance elements installed in different parts of the machine are used for continuous monitoring of the temperature of the parts The connection cables of the elements are routed to junction boxes on the outside of the stator housing The number and location of the elements are shown . removal efficiency: 100 percent for particles of 8 microns and larger, 99 percent for particles of 6 to 8 microns, 90 percent for particles of 4 to 6 microns, and 85 percent for particles of 2 to. liquid removal efficiency of 100 percent for particles 3 microns and larger, and 99.98 percent for particles less than 3 microns. Solids removal efficiency: 100 percent for particles of 3 microns and. 99.5 percent for particles of 0.5 to 3 microns. Line separators Definition: Vertical vane-type separator with liquid removal efficiency of 100 percent for removal of particles 10 microns and larger. Fuel