Showing papers by "Westinghouse Electric published in 2002"

Advances in Parabolic Trough Solar Power Technology

Abstract: Parabolic trough solar technology is the most proven and lowest cost large-scale solar power technology available today, primarily because of the nine large commercial-scale solar power plants that are operating in the California Mojave Desert. These plants, developed by Luz International Limited and referred to as Solar Electric Generating Systems (SEGS), range in size from 14-80 MW and represent 354 MW of installed electric generating capacity. More than 2,000,000 m 2 of parabolic trough collector technology has been operating daily for up to 18 years, and as the year 2001 ended, these plants had accumulated 127 years of operational experience. The Luz collector technology has demonstrated its ability to operate in a commercial power plant environment like no other solar technology in the world. Although no new plants have been built since 1990, significant advancements in collector and plant design have been made possible by the efforts of the SEGS plants operators, the parabolic trough industry, and solar research laboratories around the world. This paper reviews the current state of the art of parabolic trough solar power technology and describes the R&D efforts that are in progress to enhance this technology. The paper also shows how the economics of future parabolic trough solar power plants are expected to improve.

Hybrid ceramic material composed of insulating and structural ceramic layers

Abstract: A hybrid ceramic structure (10), for use in high temperature environments such as in gas turbines, is made from an insulating layer (12) of porous ceramic that is thermally stable at temperatures up to 1700 C bonded to a high mechanical strength structural layer (8) of denser ceramic that is thermally stable at temperatures up to 1200 C, where optional high temperature resistant adhesive (9) can bond the layers together, where optional cooling ducts (11) can be present in the structural layer and where hot gas (14) can contact the insulating layer (12) and cold gas (15) can contact the structural layer (8).

Ceramic matrix composite component for a gas turbine engine

Abstract: A ceramic matrix composite (CMC) component for a combustion turbine engine ( 10 ). A blade shroud assembly ( 30 ) may be formed to include a CMC member ( 32 ) supported from a metal support member ( 32 ). The CMC member includes arcuate portions ( 50, 52 ) shaped to surround extending portions ( 46, 48 ) of the support member to insulate the metal support member from hot combustion gas ( 16 ). The use of a low thermal conductivity CMC material allows the metal support member to be in direct contact with the CMC material. The gap ( 42 ) between the CMC member and the support member is kept purposefully small to limit the stress developed in the CMC member when it is deflected against the support member by the force of a rubbing blade tip ( 14 ). Changes in the gap dimension resulting from differential thermal growth may be regulated by selecting an angle (A) of a tapered slot ( 76 ) defined by the arcuate portion.

A comparison of balloon- and self-expanding stents

Abstract: This paper summarizes some of the key differences between self-expanding and balloon-expanding stents, aligning engineering and design differences with clinical performance While neither type of stent can be considered universally superior, the differences are significant enough to make each type more appropriate in specific circumstances Many of the differences concern long-term outcome, for which there is still insufficient data

Tubular Solid Oxide Fuel Cell/Gas Turbine Hybrid Cycle Power Systems: Status

Abstract: The solid oxide fuel cell (SOFC) is a simple electrochemical device that operates at 1000°C, and is capable of converting the chemical energy in natural gas fuel to AC electric power at approximately 45% efficiency (net AC/LHV) when operating in a system at atmospheric pressure. Since the SOFC exhaust gas has a temperature of approximately 850°C, the SOFC generator can be synergistically integrated with a gas turbine (GT) engine generator by supplanting the turbine combustor and pressurizing the SOFC, thereby enabling the generation of electricity at efficiencies approaching 60% or more. Conceptual design studies have been performed for SOFC/GT power systems employing a number of the small recuperated gas turbine engines that are now entering the marketplace. The first hardware embodiment of a pressurized SOFC/GT power system has been built for Southern California Edison and is scheduled for factory acceptance tests beginning in Fall 1999 at the Siemens Westinghouse facilities in Pittsburgh, PA. The hybrid power cycle, the physical attributes of the hybrid systems, and their performance are presented and discussed.

Ceramic matrix composite structure having integral cooling passages and method of manufacture

Abstract: A multi-layer ceramic matrix composite structure (40) having a plurality of fiber-reinforced cooling passages (42) formed therein. The cooling passages are formed by the removal of a fugitive material. The fugitive material is part of a wrapped fugitive material structure containing a layer of reinforcing ceramic fibers (26) that is used to lay-up the multi-layer structure. An intermediate layer of ceramic fabric may be placed alternately over and under the wrapped fugitive material structure to separate the cooling passages into alternating upper and lower cooling passages. The transversely oriented fibers surrounding the cooling passages serve to increase the interlaminar strength of the structure when compared to prior art designs. An airfoil member incorporating such reinforced integral cooling passages is provided.

Composite structure formed by cmc-on-insulation process

Abstract: A method of manufacturing a composite structure uses a layer of an insulating material ( 22 ) as a mold for forming a substrate of a ceramic matrix composite (CMC) material ( 24 ). The insulating material may be formed in the shape of a cylinder ( 10 ) with the CMC material wound on an outer surface ( 14 ) of the cylinder to form a gas turbine combustor liner ( 20 ). Alternatively, the insulating material may be formed in the shape of an airfoil section ( 32 ) with the CMC material formed on an inside surface ( 36 ) of the insulating material. The airfoil section may be formed of a plurality of halves ( 42, 44 ) to facilitate the lay-up of the CMC material onto an easily accessible surface, with the halves then joined together to form the complete composite airfoil. In another embodiment, a box structure ( 102 ) defining a hot gas flow passage ( 98 ) is manufactured by forming insulating material in the shape of opposed airfoil halves ( 104 ) joined at respective opposed ends by platform members ( 109 ). A layer of CMC material ( 107 ) is then formed on an outside surface of the insulating material. A number of such composite material box structures are then joined together to form a vane ring ( 100 ) for a gas turbine engine.

Mixed powder deposition of components for wear, erosion and abrasion resistant applications

Abstract: An abrasive coating and a process for forming the abrasive coating by co-depositing hard particles within a matrix material onto a substrate using a cold spray process. The cold sprayed combination of hard particles and matrix material provides a coating that is wear, erosion and oxidation resistant. The abrasive coating may have different compositions across its depth. The hard particles may be deposited at different densities across the thickness of the matrix material. A first layer of the abrasive coating proximate the surface of the substrate may be devoid of hard particles.

Evaluation of the Potential of Laser-Induced Breakdown Spectroscopy for Detection of Trace Element in Liquid

Abstract: The analytical figure of merit of the potential of laser-induced breakdown spectroscopy (LIBS) has been evaluated for detection of trace element in liquid. LIBS data of Mg, Cr, Mn, and Re were studied. Various optical geometries, which produce the laser spark in and at the liquid sample, were tested. The calibration curves for Mg, Cr, Mn, and Re were obtained at the optimized experimental conditions with bulk liquid and in liquid jet. It was found that measurements using a liquid jet provide better detection limits than bulk liquid measurements. The limits of detection (LOD) of Mg, Cr, Mn, and Re in the present liquid jet measurement are found to be 0.1, 0.4, 0.7, and 8 ppm, respectively. The LOD of Mg using Mg 279.55 nm was compared with the values found in other liquid work.

Method and apparatus for instrumenting a gas turbine component having a barrier coating

Abstract: A method ( 50 ) of instrumenting a component ( 10 ) having a barrier coating ( 14 ). A sensor ( 76 ) is embedded within or below the coating. Material forming the sensor is deposited within a trench ( 80 ) formed into the barrier coating. The trench is then backfilled with material ( 70 ) to protect the sensor from the environment within which the component is operating. In this manner, the sensor may be embedded at any desired location and any desired depth within a barrier coating on a previously fabricated component. An array of sensors ( 98, 100, 102 ) may be embedded across the depth of the coating to provide signals indicative of operating conditions across the coating. The signals may be conducted to a connection location ( 24 ) by conductors ( 62, 64 ) that are deposited within the trench. The trench may be formed with a laser engraving process ( 54 ) and the material for the sensor and conductors may be deposited with a selective laser melting process ( 58 ).

Schedule-based load estimator and method for electric power and other utilities and resources

Abstract: A method for schedule-based load estimation in a system including a utility energy provider and a utility energy consumer, comprises the steps of generating a near-term proposed schedule set containing at least one near-term proposed schedule for operation of power-consuming resources; monitoring energy consumption of the consumer for providing a set of historical consumption data; providing from priorly stored data a set of historical schedule data for the consumer; providing a set of historical unscheduled factors that affect the consumer's power consumption; providing a set of unscheduled factor predictions; and performing a correlation operation on the near-term proposed schedule set, the set of historical consumption data, the set of historical schedule data, the set of historical unscheduled factors, and the set of unscheduled factor predictions, for providing a respective near-term load estimate for each near-term proposed schedule in the near-term proposed schedule set.

Honeycomb structure thermal barrier coating

Abstract: A device having an improved thermal barrier coating (46) and a process for manufacturing the same. A support structure (28) for retaining a ceramic insulating material (46) on a substrate (16) is formed by the deposition of a support structure material through a patterned masking material (14). The support structure can define cells into which the ceramic insulating material is deposited following removal of the masking material. The masking material may be patterned by known photolithographic techniques (22, 24) or by laser etching (48). The support structure (28) may be a composite metal-ceramic material having either discreet layers (30, 34) or a graded composition and may be deposited by an electro-deposition process followed by a heat treatment to form a solid state diffusion bond with the substrate. The ceramic filler material may be deposited (44) by the electrophoretic deposition of ceramic particles coated with a bonding material that is subsequently heated to oxidize and to bond the particles together. The support structure may be provided with included walls in order to improve its resistance to foreign object impact damage.

Ultra-low emission power plant

Abstract: An integrated gasification power generating system ( 100 ) includes an oxygen separator ( 1 ) for providing an oxygen rich gas stream ( 2 ) from an oxygen containing gaseous mixture such as air ( 13 ). The oxygen separator ( 1 ) provides an oxygen stream ( 2 ) preferably including at least 99% oxygen. The system includes a gasifier ( 25 ) for generating a synthesis gas and a combustor ( 21 ) for combusting a mixture including the oxygen rich gas stream ( 20 ), a steam flow ( 23 ) and the synthesis gas ( 22 ) or a product derived therefrom, to produce thermal energy.

Protective overlayer for ceramics

Abstract: A xenotime phosphate protective overlayer ( 22 ) for protecting a ceramic material ( 24 ) from a high temperature, moisture-containing environment. Yttrium phosphate may be used as a protective overlayer to protect an underlying mullite layer to temperatures in excess of 1,500° C. The coating may have porosity of greater than 15% for improved thermal shock protection. To prevent the ingress of oxygen to an underlying ceramic non-oxide material, such as silicon carbide or silicon nitride, an oxygen barrier layer ( 34 ) is disposed between the xenotime phosphate coating and the non-oxide material. Such a protective overlayer may be used for an article having a ceramic matrix composite substrate.

Introducing the family of "Sen" transformers: a set of power flow controlling transformers

Abstract: Real and Reactive power flow in an alternating current transmission line are independently controlled by connecting, to the transmission line, a series-compensating voltage, which is variable in magnitude and at variable angle with respect to the transmission line voltage as well as the prevailing line current. The traditional technology of transformer and tap changer is used to implement this novel technique. An additional voltage regulation capability can also be implemented. The speed of tap changer operation determines the response time of this power flow controller, which is quite adequate in most utility applications. The response time can be improved if suitable solid-state switches are available to replace the mechanical taps.

Development of Swirling Flow in a Rod Bundle Subchannel

Abstract: Experimental measurements of the axial development of swirling flow in a rod bundle subchannel are presented. Swirling flow was introduced in the subchannel from a split vane pair located on the downstream edge of the support grid. Particle image velocimetry using an optical borescope yielded full-field lateral velocity data. Lateral flow fields and axial vorticity fields at axial locations ranging from 4.2 to 25.5 hydraulic diameters downstream of the support grid were examined for a Reynolds number of 2.8×10 4

Business management system and method for a deregulated electric power market with sharing of supply chain data

Abstract: A business management method for trading in load estimations with interaction between an electrical energy supplier and a plurality of customer energy consumers, comprises the steps of: grouping the plurality of customers into respective customer circles such that each circle comprises a number of customers engaged in similar activities; developing respective load profiles for each of the customer circles for a predetermined period past; inputting the respective load profiles to an aggregate load profile estimator for providing an aggregate load estimate; and trading in the load estimate. The method is likewise applicable to other commodities such as a water supply, fuel gas supply, or the like.

Health monitoring display system for a complex plant

Abstract: A single page enterprise wide level display provides a comprehensive readily understood representation of the overall health status of a complex plant. Color coded failure domains allow rapid intuitive recognition of component failure status. A three-tier hierarchy of displays provide details on the health status of the components and systems displayed on the enterprise wide level display in a manner that supports a logical drill down to the health status of sub-components on Tier 1 to expected faults of the sub-components on Tier 2 to specific information relative to expected sub-component failures on Tier 3.

System and method for supporting fuel nozzles in a gas turbine combustor utilizing a support plate

Abstract: A system for supporting a plurality of fuel nozzles in a combustor includes a plurality of fuel nozzles coupled to a fuel nozzle support housing proximate an upstream end of each fuel nozzle, a plurality of swirler vanes rigidly coupled to respective fuel nozzles proximate an intermediate portion of the fuel nozzle, a plurality of shrouds rigidly coupled to respective swirler vanes, each shroud having an upstream end adjacent the intermediate portion of the fuel nozzle and a downstream end and a support plate rigidly coupled to the plurality of shrouds proximate an intermediate portion of each of the shrouds. The support plate has a perimeter approximately equal to an inside perimeter of combustor housing which allow the support plate to limit the movement and vibration of the fuel nozzles.

Wear and erosion resistant alloys applied by cold spray technique

Abstract: A wear alloy coating (14) applied to a substrate material (12) by a cold spray process. Particles of the wear alloy coating material (16) are directed toward a target surface (18) of the substrate at a velocity sufficiently high for the particles to deform and to adhere to the target surface. The size and composition of the particles may be varied during the cold spray process to produce a coating with a varying property across the depth of the coating. Particles of the wear alloy material may be applied by cold spraying along with particles of a second material such as a lubricant or a ceramic material. For Group 5 hard facing materials, the size and distribution of the embedded carbide nodules may be controlled by controlling the selection of the carbide particles being sprayed. The cold spray process permits a wear alloy coating to be applied proximate a brazed joint or over a directionally stabilized or single crystal material without degrading the underlying material.

Business management system and method for a deregulated electric power market using online diagnostic services

Abstract: A business management method for detection of anomalies with interaction between an electric distribution company and a plurality of customer energy consumers with respective smart electric metering systems, comprises the steps of: the respective smart electric metering system providing an error message to the electric distribution company upon occurrence of an anomaly; electric distribution company performing online diagnostics upon detection of an anomaly at a respective customer energy consumer site; the electric distribution company determines whether repairs are required; and upon a determination of a need for repair, electric distribution company schedules a repair visit at the respective customer energy consumer site. The method is likewise applicable to other commodities such as a water supply, fuel gas supply, or the like.

The influence of microstructure and environment on the crack growth behavior of Powder Metallurgy nickel superalloy RR1000

Abstract: A study of crack growth in vacuum and air at 725 °C (T/T m=06) highlights the relative importance of creep and environmental crack-tip damage mechanisms in Powder Metallurgy (P/M) disc alloy RR1000 Both of these mechanisms are associated with a transition to intergranular fracture during fatigue crack growth at 025 Hz Crack growth under sustained loads reveals the precise nature of these mechanisms in RR1000 The severity of creep and environmental mechanisms is controlled by the grain-boundary microstructure and the crack-tip stress Near-tip cavitation leads to fracture in vacuum Sigma-phase precipitation causes an increase in crack growth rate through increased crack-tip cavity nucleation Rapid near-tip stress relaxation induced by γ′ coarsening has a beneficial effect on the severity of this type of damage In air, increases in crack growth rates are associated with near-tip intergranular oxidation It is proposed that the extent of this damage and subsequent growth rates are increased by sigma-phase precipitation through enhanced oxidation due to chromium depletion and subsequent decreased passivation Again, a beneficial effect of rapid near-tip stress relaxation due to selective γ′ coarsening is apparent and environmental damage is reduced under these conditions

Status of Pressurized SOFC/Gas Turbine Power System Development at Siemens Westinghouse

Abstract: Pressurized solid oxide fuel cell (PSOFC)/micro gas turbine generator (MTG) hybrid power systems have the potential to generate electric power at high efficiency [circa 60% (net AC/LHV)] at multi-hundred kWe and multi-MWe capacities. Thus, good fuel economy and low CO2 emissions are positive system attributes, as are low NOx and SOx emissions due to the propensity of the SOFC for low NOx generation, the need for no firing of the gas turbine combustor during normal hybrid system power operations, and the use of desulfurized fuel. Exhaust temperatures are sufficiently high to enable the recovery of heat for steam/hot-water production, and system energy efficiencies of at least 80% are feasible. Work is ongoing at Siemens Westinghouse on three PSOFC/MTG power systems. Two, with 220 kWe and 300 kWe capacities, are proof-of-concept demonstration units. The 220 kWe PSOFC/MTG power system is in test at the National Fuel Cell Research Center, University of California-Irvine, and the 300 kWe system, which is currently being designed, will be demonstrated in two tests to be performed in Europe. The status of work on the 220 kWe and 300 kWe power systems is reviewed. The third system is to have capacity of at least 500 kWe. This system, which will be demonstrated also, is viewed as a prototype commercial product. The 500 kWe-class PSOFC/MTG concept is described and performance estimates are presented.Copyright © 2002 by ASME

Variable exhaust struts shields

Abstract: A gas turbine engine having an exhaust casing that includes a plurality of fairings that shield struts that are affixed to and extend between concentric rings. Each fairing has a moveable tail section that is adjusted during turbine operation to change the angle of attack of the exhaust gases to minimize vortex shedding and the corresponding vibrations that result.

Automatic combustion control for a gas turbine

Abstract: A method of controlling a gas turbine engine to provide protection against damaging pressure transients in the combustion process and to ensure compliance with emission requirements. Pressure fluctuations are monitored in a plurality of frequency ranges, and unacceptable pressure transients in different frequency ranges trigger different corrective actions. Unacceptable pressure transients in low and intermediate frequency ranges trigger a change in the pilot fuel fraction of a dual-mode combustor, while unacceptable pressure transients in a high frequency range trigger immediate power reduction in the engine. A control system for a gas turbine engine includes a plurality of timers for defining consecutive time periods for alternate monitoring of pressure transients and not monitoring pressure transients. Corrective action is taken only if unacceptable pressure transients are detected in each of the monitored time periods. As the combustion process is slowly adjusted to optimize emissions, the system will respond rapidly to an indication of an unacceptable dynamic condition.

Comparison of field results and digital simulation results of voltage-sourced converter-based FACTS controllers

Abstract: This paper compares the field results of voltage-sourced converter (VSC)-based flexible alternating current transmission system (FACTS) controllers, such as static synchronous compensator (STATCOM), static synchronous series compensator (SSSC), and unified power flow controller (UPFC) with that obtained from the computer models of the FACTS controllers using an Electro Magnetic Transients Program (EMTP) simulation package. The operational results of the actual equipment include the control of the line voltage and the control of the real and reactive power flow in the line. The correlation of the results establishes the validity of the models. The protection scheme of the FACTS controllers during faults and contingencies is also described. The simulation results can be used to accurately predict the behavior of an actual controller.

Turbine blade clearance on-line measurement system

Abstract: A system (90) for measuring the gap (16) between a rotating blade (14) and a stationary component (12) of a turbo-machine, including an eddy current coil (30) and an eddy current tester (91) The eddy current tester may excite the coil in a pulsed eddy current testing mode The coil is positioned in a stationary portion (12) of a turbo-machine traversed by a rotating blade and the eddy current tester is coupled to the eddy current coil to provide an indication responsive to a distance between the blade and the stationary portion as the blade traverses the position The coil may be mounted in a frangible ceramic pill (70) movably disposed in a housing (74) The coil is positioned near the turbine blade, the coil is excited with a voltage step function (120), and the response (122) of the coil to the step function is detected and processed to determine the proximity of the blade