Abstract: The disclosure relates to a method for the scheduling and/or the operation of a system of at least two power supplies (11) providing DC pulses to a consumer (5), typically an electrostatic precipitator, wherein the power supplies (11) are energized by a common feeding (1). According to the proposed method one power supply (11) is defined to be the reference power supply, and the initial pulses of each further power supply (11) are shifted by controlled delays (?Pri) with respect to the pulses of the reference power supply so as to fill the gaps between the pulses of the reference power supply by the pulses of the further power supplies (11).

Abstract: A system for removing gaseous pollutants, such as mercury from flue gases of a solid-fueled furnace (17), includes a sorbent mill (34) that receives superheated steam and a sorbent (28), such as activated carbon, in a partially agglomerated state, that processes the sorbent (28) by de-agglomerating and comminuting the sorbent (28). An educator (35) transports the processed sorbent (28) to a distributor (36) that injects it into the flue gases at a contact location having a temperature between 500° F. and 900° F., whereupon the sorbent (28) adsorbs mercury from the flue gas. A particle collection device (24) removes the processed sorbent (28) having adsorbed mercury, from the flue gas.

Abstract: A phase angle drift method for loss of mains/grid protection is disclosed. According to one aspect, an accumulated electrical phase angle drift derived from the difference between the current measured local frequency and the estimated frequency using historical data is compared to an angle threshold. An estimated grid frequency may be calculated based on the historical delay, and the window, over which the estimated frequency is calculated. An addition/subtraction of a phase angle offset value is calculated for a half cycle is performed when the frequency difference between the estimated frequency fnest and the measured frequency fn is greater or equal to a first determined value.

Abstract: A nickel-based alloy suitable for casting gas turbine components having a lower density and basic heat treating process while achieving improved strength is disclosed. Multiple embodiments of the alloy are disclosed capable of providing both directionally-solidified and equiaxed castings. Also disclosed is a method of making a cast and heat treated article utilizing the improved nickel-base alloy.

Abstract: The present invention discloses various methods for repairing a side seal region of a transition duct aft frame region. Embodiments of the present invention include application of a braze filler material to worn locations of seal teeth, brazing of a braze preform to the seal teeth or removal of a worn seal tooth and brazing of material compatible with the transition duct to form a replacement tooth of the side seal. The transition duct is brazed in a furnace in an incremental heated process which elevates the transition duct to a temperature where the braze filler material adheres to the side seal region while also providing a stress relief to the transition duct.

Abstract: A system and method for controlling oxidation of sulfites in a slurry. The system includes a tank having an inlet for receiving a slurry used in wet flue gas desulfurization. The tank also includes an inlet for receiving a gas. The inlet for receiving the gas is configured so that at least a portion of the gas received in the tank is dispersed through at least a portion of the slurry received in the tank. A sensor is configured to measure a sulfite concentration S1 of the slurry received in the tank. In some embodiments, the sensor is a sulfite analyzer. In other embodiments, the sensor is a virtual analyzer. The system includes a controller. Software executing on the controller generates a signal indicative of an adjustment of a flow rate of gas into the tank based at least in part on the sulfite concentration S1.

Abstract: A turbo machine, especially gas turbine, comprises a rotor, which rotates about a horizontal machine axis, and which is enclosed by a coaxial enclosure comprising a metal casing, whereby an electrical heating system is provided on the lower half of said metal casing. A safe operation is achieved by having said heating system configured as a redundant system.

Abstract: A system and method for recovering a solvent from a decarbonated flue gas in an absorption column, the decarbonated flue gas having had carbon dioxide absorbed and removed by vapor-liquid contact with a carbon dioxide absorbing solution containing the solvent. The system includes an emission control section configured to bring a water stream substantially free of the solvent into contact with the decarbonated flue gas to recover the solvent from the decarbonated flue gas and to form a solvent containing wash water and a reduced solvent containing flue gas and a flue gas cooling section configured to bring cooled wash water into contact with the reduced solvent containing flue gas to cool the reduced solvent containing flue gas and condense water from the decarbonated flue gas thereby forming a cooled flue gas and used wash water.

Abstract: The invention relates to a method for operating a thermal power plant, which includes a gas turbine and a generator driven directly by the gas turbine by means of a shaft and being connected to an electrical grid having a grid frequency (FG) via an electronic decoupling apparatus and a step-up transformer. A synthetic inertia response is achieved by said method includes the steps of: sensing said grid frequency (FG); detecting if in case of an excursion of said grid frequency (FG) additional inertial power is required or not; if inertial power is required, calculating the magnitude and duration of the additional inertial power; and releasing additional inertial power to said electrical grid in accordance with said calculations via said electronic decoupling apparatus.

Abstract: An axial flow turbine is described having a casing defining a flow path for a working fluid therein, a rotor co-axial to the casing, a plurality of stages, each including a stationary row of vanes circumferentially mounted on the casing a rotating row blades, circumferentially mounted on the rotor, with within a stage n vanes have an extension such that at least a part of the trailing edge of each of the n vanes reaches into the annular space defined by the trailing edges of the remaining N-n vanes and the leading edges of rotating blades of the same stage.

Abstract: A voltage source converter includes three branches connected at a first end to a junction to form a star configuration, the second end of each branch defining a DC terminal, the second ends of the second and third branches being connectable to a first DC voltage, and the second ends of the first and second branches being connectable to a second DC voltage. The first and second branches include primary switching elements, and the third branch includes a primary inductive element. The converter includes a converter limb connected in parallel with one of the first and second branches, the converter limb including a chain-link auxiliary converter including multiple series-connected modules controllable to selectively provide a voltage source to modify a branch voltage across the branch connected in parallel with the converter limb, each module including at least one secondary switching element and at least one energy storage device.

Abstract: The invention relates to a steam turbine governing system for maintaining synchronization between an electrical grid and an electric generator, driven by a steam turbine, after the occurrence of a grid short circuit at the electrical grid. The governing system includes a governor adapted to control an arrangement of valves for regulating the steam flow in the steam turbine and means for measuring the voltage drop at the output of the electric generator. The governing system further includes means for measuring the electric power drop at the output of the electric generator. The governor is adapted to initiate operation of the arrangement of valves of the steam turbine in response to a voltage drop exceeding a predetermined value and to an electric power drop exceeding a predetermined value.

Abstract: A method for filtration of harmful gas effluents from an industrial installation including the steps of providing a gas effluent from an industrial installation, the gas effluent including a mixture of gases; filtering the harmful, elements from the gas effluent by membrane separation through a plurality of membranes, the membrane separation being achieved by sifting, sorption and/or diffusion, each membrane being adapted for filtering a specific harmful element; sorting the filtered harmful elements and storing them in separate storage reservoirs, and discharging the processed gas effluent to the atmosphere.

Abstract: A compressor component having an improved airfoil profile so as to eliminate previously known vibratory issues in the blade tip is disclosed. By altering the airfoil profile throughout its span, the natural frequency of the airfoil is altered so as to not coincide with a critical engine order of the compressor. Further, the present invention provides a novel airfoil profile in accordance with the coordinates of Table 1.

Abstract: A component or coupon for use in a thermal machine under extreme thermal and mechanical conditions comprises an alloy material having a controllable grain size (d). A grain size distribution (d(X,Y,Z)) of the component or coupon corresponds to at least one of an expected temperature distribution (T(X,Y,Z)), an expected stress distribution (?(X,Y,Z)) and an expected strain distribution (?(X,Y,Z)), which vary with geometrical coordinates (X,Y,Z) of the component or coupon, such that a lifetime of the component or coupon is improved with respect to a similar component or coupon having a substantially uniform grain size.

Abstract: A seal arrangement is installed between confronting co-planar portions of a low pressure steam turbine exhaust hood and a circular bulkhead that forms part of an exhaust duct structure of a steam turbine module. The seal arrangement forms a vacuum seal between the interior and exterior of the exhaust hood and comprises a flexible gasket in the form of an annular diaphragm. This diaphragm has a radially inner circumferential portion that seals with the bulkhead, a radially outer circumferential portion that seals with the exhaust hood, and a radially median resilient portion. Sealing is achieved by providing radially inner and outer clamping flanges operative to sealingly clamp inner and outer circumferential portions of the gasket to the bulkhead and the exhaust hood respectively.

Abstract: The present invention relates to an on-load tap changer control method for a power excitation chain. The chain includes a generator, a step-up transformer equipped with an on-load tap changer and connected on the one hand to the output of the generator and on the other hand to a transmission bus, and an excitation control system with a generator automatic voltage regulator (AVRG) and one excitation limiter (OELG, UELG). The method monitors the excitation conditions of the generator, activates the one excitation limiter (OELG, UELG) when the monitored excitation conditions are outside a predefined range, and temporarily inhibits the change of step of the on-load tape changer.

Abstract: An inspection vehicle for inspecting a substantially cylindrical object composed of a magnetizable material includes a chassis. A plurality of wheels is disposed on the chassis so as to be rotatable and is configured to move the chassis in a circumferential direction along an external surface of the cylindrical object, at least some of the plurality of wheels being motor-drivable. The plurality of wheels is disposed so as to provide a chassis clearance allowing a movement of the chassis over an obstruction on the external surface of the cylindrical object. A magnetic device is disposed on the chassis and is configured to hold the vehicle on the external surface of the cylindrical object.

Abstract: A spray dryer absorber operative for removing gaseous pollutants from a hot process flue gas and a vibrator device for removing accumulated deposits therefrom is provided. The spray dryer absorber includes a spray dryer chamber equipped with a plurality of dispersers and atomizers mounted at a roof of the spray dryer chamber. The vibrator device is operative to remove accumulated deposits from the spray dryer absorber and its components, such as its dispersers and atomizers, to avoid spray dryer absorber performance interference caused by such deposit accumulations.

Abstract: The invention concerns energy delivery system and method for a gate drive unit controlling a thyristor-based valve (19). The system comprises at least one current transformer (22) located in the main current path of the valve.