Showing papers by "Westinghouse Electric published in 1977"

Stabilization of tetragonal phase in polycrystalline zirconia

Abstract: It is shown that the tetragonal phase can be stabilized in the sintered body of a partially stabilized zirconia (PSZ) containing low concentrations of yttria. Such sintered body containing the metastable phase undergoes stress-induced phase transformation by the absorption of thermal or mechanical stress and exhibits strengths in excess of 690 MPa (100ksi).

Preparation of glasses and ceramics from metal-organic compounds

Abstract: The preparation of glass and ceramic systems from metal-organic compounds permits the mixing of the constituents at the molecular level. These mixes form clear glasses or sinter to dense bodies at temperatures considerably lower than the equivalent compositions prepared by classical methods. A significant recent development in this field has been the preparation of monolithic glass and ceramic material without the need of melting or high temperature sintering. Glass-forming reactions, previously achievable only by thermal means, can take place by chemical polymerization at room temperatures. Structural studies indicate that these materials are indeed amorphous or glassy in naturE. Thus, the often used description of glass as a “supercooled liquid” is, in the literal sense, inapplicable for these materials.

Crack Growth During Low-Cycle Fatigue of Smooth Axial Specimens

Abstract: Crack growth data are reported for small axially loaded smooth specimens of A533B steel subjected to strain cycling fatigue at large plastic strains. Surface crack lengths were monitored using cellulose acetate replicas, and occasional specimens were broken open to determine crack depth. Experimental crack growth rates for different strain levels are correlated in fracture mechanics fashion by the J integral concept, with J values being estimated from stress-strain hysteresis loops. The crack growth rate data of this investigation are compared with previous data for the same material obtained from linear elastic fracture mechanics tests. It is suggested that research on the behavior of small cracks is fundamental to a better understanding of the fatigue process.

Phase Relations and Stability Studies in the Si3N4‐SiO2‐Y2O3 Pseudoternary System

Abstract: Composite powders were hot-pressed to determine the phase relations in the Si/sub 3/N/sub 1/-SiO/sub 2/-Y/sub 2/O/sub 3/ pseudoternary system. Four quaternary compounds, Si/sub 3/Y/sub 2/O/sub 3/N/sub 4/, YSiO/sub 2/N, Y/sub 10/Si/sub 7/O/sub 23/N/sub 4/, and Y/sub 4/Si/sub 2/O/sub 7/N/sub 2/, were identified. Studies of polyphase and single-phase materials in this system showed that these 4 compounds are unstable under oxidizing conditions. Materials within the Si/sub 3/N/sub 4/-Si/sub 2/N/sub 2/O-Y/sub 2/Si/sub 2/O/sub 7/ compatibility triangle precluded the unstable compounds, and are extremely resistant to oxidation.

The fundamentals of chemical vapour deposition

Abstract: Fundamentals of the chemical vapour deposition process are described and examples given of its application. The most important aspects of the process are reviewed; these include deposit structure (with its relation to process parameters), process control through application of the principles of thermodynamics and reaction kinetics (with emphasis on deposit thickness uniformity, deposit composition control and deposit-substrate adherence) and basic design features of the equipment used.

Static Exciters for Induction Generators

Abstract: The utilization of the squirrel cage induction motor as an autonomous induction generator is briefly reviewed. In view of potential new applications, the discussion focuses on a simple exciter scheme based on using a static reactive power generator implemented with fixed capacitors and thyristor controlled inductors. The feasibility of the proposed scheme with naturally commutated thyristors is verified by measurements on a test setup employing a standard 15-hp induction motor.

Method and apparatus for eccentricity correction in a rolling mill

Abstract: A method and apparatus is disclosed for eccentricity correction in a rolling mill, in which prior to rolling, the eccentricity of the back-up rolls is measured and recorded both initially and each time the back-up rolls are changed. In an analog loop, constant roll gap is maintained by bidirectionally displacing the back-up rolls so as to maintain constant roll force in accordance with a reference roll force signal, the displacements being such as to neutralize the measured and recorded eccentricity. In a digital feedback loop, controlled by a digital computer, roll force is maintained constant in accordance with changes in the gauge of the work product, with the displacement of the back-up rolls producing a change in roll opening. The analog and digital control loops are cooperatively combined, so that the change in roll opening resulting from digital control, produces a new roll force reference for the analog loop. Effectively then, the intercooperation of analog and digital loops simultaneously produces roll eccentricity and gauge change compensation.

Influence of particles on AC and DC electrical performance of gas insulated systems at extra-high-voltage

Abstract: High-voltage breakdown measurements were made in two similar particle contaminated coaxial test systems, one with AC and the other with DC voltages. Information is presented on the effects of particle size, shape, and material for both SF 6 and N 2 gases at pressures up to 15 atm in a plain coaxial gap and a coaxial gap including a post-type support spacer. Particle motion and location were found to strongly influence insulation performance. Measured values of electric fields which lifted and drove the particles, so that they bounced vertically and laterally, compare favorably with calculated levels. Movement into the the higher stress region at the center conductor was correlated with the initiation of sparkover. These breakdowns could be at levels more than a factor of five lower than those obtained when contamination was not introduced. Large variations in breakdown voltage of as much as 3 to 1 encountered under DC correspond to conditions where particle motion could be restricted, presumably by corona discharge, to motion near the outer electrode. AC sparkover levels were typically at the lower limits of the DC range. Both free and attached particles on the dielectric spacer surface would trigger flashover at the same low levels as were measured in the gas gap.

Hybrid combustor with staged injection of pre-mixed fuel

Abstract: A combustor for a gas turbine engine which includes a fuel nozzle at the head end of the combustor, to provide a diffusion flame, and downstream inlet means at a plurality of axial dimensions of the combustor to inject pre-mixed lean fuel/air into the combustor for admission downstream from the diffusion flame resulting in a series of low temperature premixed flames to provide relatively high turbine inlet temperatures from the combustor with a minimum of thermally formed NOx compounds.

Digital processing and calculating ac electric energy metering system

Abstract: A metering system for electric utility power line measurements includes voltage and current signal inputs that are randomly sampled and converted to binary representations. A system sequence controller and calculator provides programmed control for processing digital control and data signals and for producing digital calculations of electric energy parameters from the binary representations of the instantaneous signal values. Memory registers totalize and accumulate digitally calculated values for producing visual displays and output signals that correspond to electric energy parameters to be measured.

High voltage signal coupler for a distribution network power line carrier communication system

Abstract: A high voltage signal coupler couples carrier communication signals between a distribution network primary conductor and communication elements located at spaced intervals on the distribution network. A single bushing, high frequency, coupling capacitor communicates the carrier communication signals between one of the distribution network primary conductors and a conductor which is at ground or real earth potential with respect to power current frequencies. A parallel resonant circuit, formed by a tuning capacitor and a hollow core of magnetic material inductively surrounding the power frequency ground conductor, couples the carrier communication signals to the communication elements connected thereto at a predetermined frequency without interfering with the operation of the ground conductor at the frequency of the power current.

Tagging particles which are easily detected by luminescent response, or magnetic pickup, or both

Abstract: Small particles for tagging of objects to be identified comprise luminescent material plus other material which provides information indicia for tagging purposes. Included in the tagging particles are very small particles of magnetic material which is reflective both for the radiations which excite the luminescent material and also for the radiations generated by the excited luminescent material. The inclusion of the reflective magnetic particles introduces only a minimal decrease in the effectiveness of the luminescent material to provide a spotting or locating function. The particles may thus be located either by their luminescent response, or by magnetic pickup, or both. Inorganic species of these particles are especially useful for tagging explosives for post-explosion indentification of the explosives.

Simplified transmission and generation system analysis procedures for subsynchronous resonance problems

Abstract: An analysis of subsynchronous resonance problems requires a clear understanding of the physical relationships that produce the phenomenon. This paper presents these relationships and uses them to derive a number of useful formulas for studying the problems. The mathematical basis of these formulas is shown and the approximations required for their derivation are described. These formulas are most useful in planning a series capacitor compensated transmission system to avoid or minimize subsynchronous resonance problems. This application is the subject of a companion paper.

Kalman estimator tracking system

Abstract: A radar tracking system having a Kalman estimator is disclosed. The estimator is provided with angle and range track error measurements in a coordinate system that is aligned with and normal to the antenna line of sight, commonly referred to as the LOS coordinate system. This estimator implementation uses less computing resources in converting the measurements provided relative to the antenna LOS coordinate system, to predict target position referenced to a stable coordinate system such as geographic, wander azimuth, or inertial.

Modular operating centers and methods of building same for use in electric power generating plants and other industrial and commercial plants, processes and systems

Abstract: Modular operating centers for use in electric power generating plants and other industrial and commercial plants, processes and systems are constructed by using a novel prefabricated modular technique. This technique includes loading a plurality of transportable room-size building modules with control system equipment at a factory site. Typically, the control system equipment includes sophisticated and complex electrical and electronics data processing and control equipment. The control system equipment is installed and bolted down in the different building modules and the equipment in each module is inter-wired at the factory site. Temporary inter-module connections are established between the control system equipment in different ones of the building modules and such equipment, as a whole, is then thoroughly tested and adjusted under simulated use conditions. Thereafter, the loaded and tested building modules are separated and separately transported to the industrial or commercial installation site. At the installation site, the building modules are joined together to form an integral weatherproof building structure and the inter-module control system equipment connections are re-established to provide a tested and substantially ready-to-go control center for the plant, process or system in question. A novel feature of this technique is that structural building modules are used as the shipping containers for transporting complex electrical and electronics equipment to the final installation site.

Threat signal detection system

Abstract: A tracking system for predicting the incidence of threat signals having at least one beam at a predetermined location in space in which a receiver detects the incidence of the threat signals at the predetermined location, a tracker cooperates with the receiver to predict the detection of threat signals by the receiver, and a controller condenses threat signals from harmonically related beams of a pulse group detected by the receiver and controls the predictions of the tracker in response to the characteristics of the condensed threat signals.

Apparatus for hydraulically expanding a tube

Abstract: A mandrel that forms an annular space when inserted within a tube and has O rings adjacent each end and a leading end having a tapered portion and a spring cooperatively associated with the O ring to facilitate sliding the mandrel into the tube and forming a fluid-tight seal adjacent the leading end of the mandrel so that pressurized fluid can be introduced into the annular space to expand the tube into engagement with a tube sheet.

Secure television transmission system

Abstract: A system for transmitting a secure television image is as disclosed. At the transmitter each line of the television image is digitized to generate a series of digital numbers representing the complete video line. The digital numbers representing the picture portion of each scan line are cyclically rotated by a random amount leaving the synchronizing portion unchanged. The digital numbers are converted to an analog signal which is filtered to generate a composite signal with the picture portion of each line cyclically shifted by a random amount. At the receiver the signal is digitized and the picture portion of each line is rotated to restore the picture portions of each line to their original position. The process of rotation is identical to that used at the transmitter except that the amount of rotation must be adjusted to restore all portions of the picture portion of the signal to their original position. The degree of security resulting from this system depends on the complexity of the system used to determine the random rotation of the individual scan lines.

Gas turbine power plant control apparatus including an ambient temperature responsive control system

Abstract: A gas turbine power plant is provided with an industrial gas turbine which drives a generator coupled to a power system through a breaker. The turbine-generator plant is operated by a hybrid control system having digital function capability during sequenced startup, synchronizing, load buildup and steady state load, and shutdown operations. The control system also contains monitoring and protective subsystems which function through all stages of operation, with redundancy and permissive features which maximize turbine availability.

Corrosion of zirconium-base alloys: an overview

Abstract: The corrosion and hydriding performance of zirconium-base alloys under pressurized water reactor (PWR) and boiling water reactor (BWR) conditions, as gaged by a comprehensive review of the technical literature, has been evaluated. Starting with a brief historical description of the development of zirconium for cladding and structural material in nuclear reactors and the corrosion problems associated with the use of the pure metal, it is shown that the development of zirconium-base alloys proceeded down two major paths. One development involved the zirconium-tin system and led to the development of the Zircaloys, whereas the other concentrated upon zirconium-niobium materials and produced the two major alloys of this system in use today: Zr-1Nb and Zr-2.5Nb. The corrosion data generated for each system, both in and ex-reactor, are evaluated, and the benefits and potential problems associated with each alloy are discussed for both PWR and BWR applications. Potential areas of concern for the Zircaloy alloys in both applications include exposure temperature limitations and the formation of nonuniform accelerated corrosion products in the oxygenated irradiation environment. The zirconium-niobium alloys are found to be very sensitive to oxygen in the coolant and to prior heat treatment in ex-reactor experiments but show either minimum or negativemore » acceleration due to the presence of neutron irradiation. Alloys that combine these two additives (for example, Zr-3Nb-1Sn and Ozhennite-0.5) do not appear to show promise as possible replacements for the Zircaloys under present-day conditions. The lack of a unifying theory for describing the mechanisms involved in the corrosion of zirconium-base alloys may hamper seriously possible future applications under different design conditions.« less

Multi-ply laminar pasted air electrodes

Abstract: An air electrode, for use in electrochemical energy cells, is made, comprising a multi-layer hydrophilic section, consisting of at least two substantially uncompacted laminated layers of plaques cntaining loaded, catalytically active battery material; each loaded plaque consisting of a 75% porous to 95% porous metal current collector, having between about 45% to about 95% of its pore volume filled with the active material, where the weight ratio of active material:plaque current collector in the laminated layers is between 0.40:1 and 2.80:1.

Detection of arcing faults in generator windings

Abstract: A method is provided for detecting the presence of arcing faults in the stator windings of large dynamoelectric machines, such as turbine generators. Arcing faults, such as broken strands in a winding conductor with continued arcing, give rise to high frequency currents which flow in the neutral lead of the generator winding. The presence of the arcing fault can thus be detected by observing the high frequency neutral currents and monitoring them for the presence of the characteristic frequency distribution resulting from the resonance characteristics of the current path.

Load balancing system for ups rectifiers

Abstract: In order to maintain a balanced load between power rectifiers operating in parallel within an uninterruptible power system, individual closed loops are established for regulating the direct current voltage at the output of the rectifiers and an open loop generates a reference voltage for each of such regulations. An operational amplifier is used as a current source to develop a current representative of the load in a particular rectifier. Parallel current dissipating resistors between each rectifier line and a floating potential common to all rectifier lines generates a reference voltage which is proportional to the average of such current dissipations and represents the average rectifier load.

Multiple side entry root for multiple blade group

Abstract: A multiple number of rotatable, axial flow turbine blades having a common platform and shroud portion from which two arcuately separated, axially extending, side entry roots protrude radially inwardly toward the axis of rotation of a rotatable shaft.

Study of the MHD spectrum of an elliptic plasma column

Abstract: The MHD spectrum associated with small perturbations about an analytic equilibrium is determined for a configuration with magnetic flux surfaces which are nested similar elliptic cylinders generated by a uniform axial current. Since the system is periodic, it models the essential features of a toroid. Both analytic and numerical techniques are used to investigate many properties of the modes, including the continuous shear Alfven and slow acoustic spectra as well as the discrete modes associated with fast magnetosonic waves, kinks, and instabilities where the interchange criterion is violated. In particular, the relationship between discrete and continuum modes is described both qualitatively and quantitatively, and it is shown how the unstable interchange modes emerge from the shear-Alfven branch of the spectrum.