Abstract: The present invention provides an eddy current sensing device capable of in-situ operation within a high temperature and high vibration environment of a combustion turbine engine. The eddy current sensing device is preferably utilized in an eddy current sensing system for monitoring crack formation and displacement of rotating members of the combustion turbine engine. The method according to the present invention provides inducing eddy currents in the rotating member, detecting the eddy currents, providing a signal indicative of the detected eddy currents, filtering the signal based on the condition to be monitored and evaluating the filtered signal to determine whether the condition, such as the formation of a crack in the surface of the rotating member exists, and if so, determining whether the condition is critical or routine.

Abstract: A method of reducing turbine inlet temperature excursions during sudden load demand reductions on a steam turbine, the turbine being coupled to a controllable source of high pressure, high temperature steam, incorporates throttling of steam within the steam source in conjunction with steam throttling at the turbine so as to apportion temperature drops between the source and turbine. In one form, the method includes the steps of sensing a sudden drop in load demand on the steam turbine, operating the steam source to reduce exit pressure of the steam at the steam source and bypassing sufficient steam around the steam turbine to reduce steam flow through the turbine by an amount commensurate with the drop in load demand.

Abstract: A gas turbine system in which the expanded gas from the turbine section is used to generate the steam in a heat recovery steam generator and to heat a mixture of gaseous hydrocarbon fuel and the steam in a reformer. The reformer converts the hydrocarbon gas to hydrogen and carbon monoxide for combustion in a combustor. A portion of the steam from the heat recovery steam generator is used to cool components, such as the stationary vanes, in the turbine section, thereby superheating the steam. The superheated steam is mixed into the hydrocarbon gas upstream of the reformer, thereby eliminating the need to raise the temperature of the expanded gas discharged from the turbine section in order to achieve effective conversion of the hydrocarbon gas.

Abstract: A turbine blade assembly is provided which comprises a rotor which is rotatable about a turbine axis of rotation and a plurality of turbine blades supported by the rotor where each of the turbine blades has a root and the rotor is provided with a plurality of grooves which terminate in a projection. Each groove is shaped for holding each root in a manner such that the root and the groove have mutually contacting surfaces which apply a radially inwardly directed restraining force to the root. The root has a bottom facing the turbine axis and the groove has a base which is located radially inwardly of, and faces, the root bottom. Positioned between the root bottom and the groove base is a lock strip and disc spring assembly for pressing together the mutually contacting surfaces of the root and the groove.

Abstract: Apparatus for evacuating and charging a refrigeration unit having a compressor; a condenser; a receiver; an evaporator; hot gas, liquid and suction lines; and suction, discharge and liquid line service valves each having a service port position. A vacuum pump is provided which has first, second and third vacuum hoses respectively connected to the suction, discharge and liquid line service valves, with each vacuum hose having a controllable valve. Refrigerant supply apparatus is provided which is connected to the liquid line service valve.

Abstract: A transport refrigeration system having electrical control which controls the temperature in a served space via heating and cooling cycles using hot refrigerant gas from a refrigerant compressor. The refrigeration system has high and low pressure sides. The high pressure side includes a discharge manifold of the compressor, a condenser coil, a refrigerant receiver tank, and an evaporator coil associated with the served space. The low pressure side extends from the evaporator coil to a suction manifold of the compressor. A first controllable refrigerant flow path means is controlled by the electrical control to purge the condenser coil in response to predetermined system parameters, causing refrigerant trapped in the condenser coil to flow to the low pressure side of the system.

Abstract: A method of testing a gas-cooled electrical generator (12) for leakage of pressurized coolant gas includes steps of communicating a container (14) with pressurized coolant gas that is within the generator (12); sealing the container (14) once the container (14) becomes filled with coolant gas at a pressure which is equal to a pressure within the sealed space; and subsequently comparing the pressure in the sealed space with the pressure in the sealed container (14), whereby a lower pressure in the sealed space will indicate coolant leakage. Preferably, the container (14) is insulated to preserve the coolant gas at the temperature it was at within the generator (12), for accurate measurements. In contrast to previously known methods, this method can be performed while the generator is operational, resulting in improved and more realistic detection and measurement of leakage.

Abstract: A combined combustion and steam turbine power plant which includes a steam turbine unit, a boiler unit for supplying steam to the steam turbine unit, and a combustion turbine unit with an exhaust gas duct structure for supplying the turbine exhaust gases to the boiler unit, has at least one heat recovery steam generator arranged in the exhaust gas flow downstream of the boiler unit and connected to the steam-turbine unit so as to supply any steam generated in the heat recovery steam generator to the steam turbine unit.

Abstract: Methods and apparatus for checking the position and condition of a return air temperature sensor in a refrigeration system. The refrigeration system draws air from a served space in heat exchange relation with an evaporator coil, and discharges conditioned air into the served space, to maintain a predetermined set point temperature SP via selectable refrigeration cycles. The return air sensor provides a value RA responsive to the temperature of the air on the return side of the evaporator coil. A discharge air temperature sensor provides a value DA responsive to the temperature of the air on the discharge side of the evaporator coil, an evaporator coil temperature sensor provides a value ECT responsive to the temperature of the evaporator coil, and an ambient air temperature sensor provides a value AA responsive to the temperature of the ambient air.

Abstract: An adaptive noise control system comprises a reference microphone (12) (FIG. 2) for generating a reference signal (x(t)) that is correlated with noise emanating from a primary noise source (10), secondary loud speaker sources (S.sub.1, S.sub.2, . . . S.sub.N) for generating a plurality of secondary sound waves, microphones (e.sub.1, e.sub.2, . . . e.sub.M) for detecting a plurality of far-field sound waves in a far-field of the primary noise source and generating a plurality of error signals (e.sub.1 (t), e.sub.2 (t), . . . e.sub.M (t)) each of which is indicative of the power of a corresponding far-field sound wave, and an adaptive controller (14) for controlling the secondary sources in accordance with the reference signal and the error signals so as to minimize the power in the far-field sound waves.

Abstract: An online valve monitoring system senses operational characteristics of a valve and provides a diagnosis of aberrations in the characteristics. Sensors, coupled to a valve, supply sensor signals as output to a data acquisition system to be transmitted to a remote location. An I/O processor at the remote location receives the sensor signals and a diagnostic processor extracts characteristic features from the sensor signals as deviations from baseline data for the valve. An expert system applies a rule base to the characteristic features individually or in combination to diagnose the causes of the deviations. Use of multiple sensors increases the confidence of the diagnosis which can be immediately communicated to an operator and used for scheduling maintenance of the valve. Use of this diagnosis and the trend line of historical data permits scheduling of preventive maintenance.

Abstract: Methods and apparatus for monitoring an arc welding process are disclosed. In a preferred embodiment, the present invention creates a digital representation of the arc created during welding and, using a neural network computer, determines if the arc is representative of normal or abnormal welding conditions. The neural network disclosed is trained to identify abnormal conditions and normal conditions and may be adaptively retrained to classify images that are not in the initial set of normal and abnormal images. In certain embodiments, other data, such as current, weld wire emission spectra, or shielding gas flow rate are also collected and the neural network is trained to monitor these data. Also, in certain embodiments, an audio signal is collected from the vicinity of the welding process and is used by the neural network computer to further classify the arc as normal or abnormal.

Abstract: A superconducting magnet coil is protected from local damage due to quenching by inductively driven heaters formed by heater strips embedded in the coil and connected in closed loops. A cold bypass diode shunting the coil winding commutates current out of the magnet when the voltage drop across the region of the coil which has gone normal exceeds the forward bias of the diode. This change in coil current induces sufficient current in the heater loops to cause the entire coil to go normal for uniform dissipation of stored energy throughout the magnet.

Abstract: A high performance steam turbine blade is provided in which the geometry of the blade airfoil is configured to minimize energy loss through the row of blades and control the radial distribution of the degree of reaction. The velocity of the steam over the blade surface is minimized to reduce friction losses, rapid deceleration of the steam velocity as it expands toward the trailing edge is avoided to prevent boundary layer separation and the reaction distribution is adjusted so that a relatively high reaction occurs at the base of the airfoil, thereby reducing secondary flow, and a relatively low reaction occurs at tip of the airfoil, thereby minimizing tip leakage. Specifically, the radial reaction distribution is such that in the hub region at least 20% of the stage pressure drop occurs in the blade row and in the tip region less than 50% of the stage pressure drop occurs in the blade row.

Abstract: A plate for spreading bolt loading around the horizontal joint flanges of a turbomachine, such as a steam turbine, is provided. The plate is contoured so that its surface area substantially matches that of the surface of the steam turbine flange against which the compressive load associated with the joint bolt preloading is applied. The plate is disposed between the flange and the nuts on the joint bolts and is made from a high yield strength material so that the locally high stresses under the nuts do not cause creeping or yielding of the plate. The plate serves to distribute the compressive joint loading around the entire surface of the flange, thereby eliminating the locally high compressive stresses that can cause creep and yielding in the flange. Spherical counter bores are machined in the plate bolt holes and spherical washers are installed between the plate and the nuts so that misalignment of bolt holes does not cause the nuts to impose bending forces on the bolts.

Abstract: An ultrasonic position sensing apparatus for detecting open, closed and intermediate positions of a valve element movably mounted in a valve housing includes an ultrasonic target fixedly attached to the valve and having an echo surface which provides a travel time difference for a returning echo, depending on the position of the valve element. An ultrasonic transducer coupled to an outer surface of the valve housing transmits an ultrasonic pulse towards the target thereby generating the echo by striking the target; a monitor means connected to the ultrasonic transducer correlates valve position to the travel time of the returning echo.

Abstract: A brush assembly for providing contact between a grounding brush and a rotating shaft, in which the noncontact time associated with brush bounce is reduced. A brush is provided which is fixed to a pivotable arm, with a bias force applied to the arm, such that when the brush is bounced from a shaft as a result of vibration or shaft wobbling, the bias force will reestablish contact between the brush and shaft. Rolling contact between a negator spring and the arm is also provided for reducing friction associated with contact between the spring and pivotable arm. Due to the reduced friction provided by the rolling contact, and more significantly by the pivotal mounting of the arm to which the brush is fixed, the response of the assembly in reestablishing contact with the shaft is greatly improved.

Abstract: An auxiliary stranded copper conductor carries the fault currents generated by a diode failure about the periphery of a brushless exciter diode wheel. The auxiliary conductor is constructed with a lower high-frequency impedance than the adjacent diode wheel, so that AC fault currents in particular are diverted to the auxiliary conductor. The auxiliary conductor carries the fault currents to equalize both AC and DC fault currents among the fuse-legs of the same phase. In a preferred embodiment, the auxiliary conductor is circular and is mounted between all of the diode fuse bases at one end of the diode wheel and the diode wheel itself.

Abstract: Fine and coarse resolvers are used to detect the length of cable withdrawn from a spool to provide an indication of the position of a neutron flux detector at the end of the cable. The position indicated by the resolvers when the neutron flux detector passes a withdrawn limit switch is stored in nonvolatile memory as an offset when the cable is first installed in a flux mapping system. Thereafter, the position indicated by the resolvers, each time the neutron flux detector passes the withdraw limit switch, is compared to the offset. If the difference between the two is significant, a warning is generated, but operation of the flux mapping system continues. During movement of the flux detector, the change in position between two readings of the resolvers is divided by an amount of time measured by a programmable interval timer to determine average speed. A warning is generated if the average speed is outside an expected range. The expected range may vary depending upon the position of the detector.

Abstract: A wall structure for insulating the exterior surface of a high voltage coil having Roebeled windings is provided that comprises an inner insulating layer formed from a hardenable epoxy material for surrounding the coil and filling void spaces on the surface of the coil created by the Roebeled windings, a ground wall layer surrounding the inner layer for grounding the wall structure, and a semiconductive layer formed from a carbon filled epoxy material integrally molded around the outer surface of the inner insulating layer for reducing the electric stress across the insulating layer and in particular across any voids remaining after the insulative layer has been applied over the Roebeled windings on the exterior of the coil. The improved wall structure advantageously increases the lifespan of high voltage coils by reducing the electric stress across the inner moulding layer, thereby reducing the probability that damaging electric arcing will ever occur in any void spaces present in this layer.