Abstract: A method of operating a gas-turbine group, combined with a downstream waste-heat steam generator and a steam consumer, in particular a steam turbine, for heat/power cogeneration. The object of the invention is to provide a method which utilizes the utilizable heat energy in the waste-heat steam generator of such a combined-cycle plant at a lower cost and reduces the output fluctuations when demand varies at the external heat consumer. According to the invention, this is achieved in that first of all a quantity of feedwater increased by the maximum heating-water quantity required is directed into the waste-heat steam generator (2). After the feedwater is heated, the additional quantity is diverted as heating water from the water/steam cycle. The diverted heating water is then supplied to the external consumer (30) and the residual heat is used to heat the feedwater tank (3).

Abstract: The cooling air cooler (10) for power plants of combined operation is designed as a helix steam generator which works on the countercurrent principle and is located in a vertically arranged cylindrical pressure vessel (23) and the spirally coiled tubes (30) of which fill the space between an inner (26) and an outer (41) jacket tube, water (12) being capable of being supplied to the tubes (30) via a conduit (32) and steam (14) being capable of being discharged from the tubes (30) via a conduit (33), the evaporating water (12) flowing through the helix from the bottom upward and the cooling air (11), capable of being supplied by the compressor (1) via an inflow conduit (24), flowing through the helix from the top downward, and the air (11) experiencing deflection before reaching an outflow conduit (25) at the lowest point in the pressure vessel (23) after flowing out of the helix.

Abstract: A switching apparatus includes a grounded, insulating gas-filled housing, the housing having a housing wall, and a power circuit-breaker disposed in the housing. The apparatus further includes a current connection for a first busbar, a current connection for a second busbar, and a current connection for a load outgoer. The apparatus further includes a grounding switch disposed in the housing, the grounding switch being connected between the power circuit-breaker and the current connection for the load outgoer, and a busbar disconnector, the busbar disconnector being connected between the current connection of the first busbar and the power circuit-breaker and between the current connection of the second busbar and the power circuit-breaker. An outwardly extended, first tubular flange arrangement is attached over a first opening in the housing wall, and an outwardly extended, second tubular flange arrangement is attached over a second opening in the housing wall.

Abstract: In the bulb-type generator, the stator laminated body (2) is suspended on the housing ring (1) by means of V-shaped elements (14). The housing ring is reinforced by the V-shaped elements. Air or cooling water can be directed for cooling purposes to the cavities (18) produced by the V-shaped elements (14) and the inner wall of the housing ring (1). In this way, a portion of the lost heat is already dissipated over flowing water when passing over the cold housing wall enlarged by the V-shaped elements (14).

Abstract: In a steam condenser in which the steam is condensed on tubes (13) through which cooling water flows and which are combined in separate banks (20), each bank (20) being subdivided into compartments (10) by supporting plates (5) arranged perpendicularly to the tubes (13), a residual-steam/inert-gas mixture is drawn out of a precooler (2) via orifices (9) into an air cooler (3). The residual steam is condensed in the air cooler (3) and the collecting condensate (23) flows off on account of a slope of the air-cooler bottom (21) through a recess (18) to an adjacent compartment (10) having an air-cooler bottom (21) situated at a lower level. In this case, the condensate (23) flowing off from a compartment (10) situated at a higher level is retained at a retaining wall (22) on the air-cooler bottom (21) of the compartment (10) having the air-cooler bottom situated at the lowest level, this retaining wall (22) being arranged parallel to a supporting plate (5).

Abstract: A reversible short circuit current limiter which has at least one PTC thermistor connected in parallel with a shunt impedance branch, and is connected in series with at least one capacitor or a capacitor bank of the DC intermediate circuit. The short circuit current limiter may be arranged in the DC intermediate circuit or in the current convertor. A diode may be connected in the reverse-bias direction of a short circuit path in parallel with the PTC thermistor. The shunt impedance branch has a varistor connected in series with an ohmic resistor or a PTC thermistor and, if appropriate, an inductor. Structures of metal-based nonblocking PTC thermistors are specified.

Abstract: A common turn-off circuit for a thyristor power converter is specified. The common turn-off circuit is particularly suitable for AC converters such as, for example, railway grid couplings. The turn-off thyristors are directly connected to the secondary transformer windings. Additionally provided is a special freewheeling path via which the energy stored, in particular, in the transformer inductors or other relevant inductors can be drawn away. What is advantageous is the fact that all of the thyristors of the power converter can be turned off reliably and without any special precautions, since the common turn-off circuit is automatically ready for turning off. Overvoltages are avoided, moreover, by the special freewheeling path.

Abstract: A multi-stage blade system of an axial flow turbo machine includes a wall (10, 11), which is on either the rotor side, the stator side, or both, which bounds the flow through the channel through which flow passes. The wall is provided, immediately at the outlet of the rotor blades (La1, La2, La3), with a kink angle (A, AA). This kink angle (A, AA) is dimensioned such that the outlet flow from the rotor blades is homogenized in terms of the total pressure and outlet flow angle. The wall (10, 11) is also provided with an opposing kink angle (B, BB) at least approximately in the inlet region of the stator blades (Le2, Le3) of the following stage. This allows the labyrinth mass flow to be reduced in blade systems having covering strip sealing.

Abstract: In the case of the method for determining the total mass flow of a gas mixture (2) which flows through a line (1) under pressure, a gas contained in the gas mixture is used as tracer (3). With the aid of pressure measurements (9, 10) of the gas mixture, total pressure and of the tracer partial pressure, the molar proportions of the tracer in the gas mixture are first ascertained. In this case the pressure measurements take place during a first phase, with the line system (1) gas-tight, and in a further phase with the system enriched with tracer.Solving the mass balances for the gas mixture and for the tracer makes it possible, by substituting the already determined tracer molar proportions, to calculate the total mass flow.Tracer enrichment of the gas mixture is carried out at supercritical pressure ratios between the vacuum prevailing in the line and the pressure of the tracer to be fed in by a critical orifice (4) which is built into the line (1) upstream of the pressure measurement locations (9, 10).

Abstract: The furnace vessel for a DC arc furnace has a thermostable wall which preferably consists, in the region situated above the slag line (S), of a plurality of water-cooled wall segments (1) made from steel. These wall segments are fastened to a support structure (13-18). At least one of the wall segments (3) consists of nonmagnetic steel or copper and is preferably arranged on the side of the furnace vessel (5) opposite the power supply device (7). In this way, the influence of the high-current lines which extend below or beside the furnace vessel and cause a deflection of the arc can be compensated.The effect of this nonmagnetic wall segment can be partially or virtually entirely cancelled by a trimming plate (19) which is detachably fastened from the outside to the nonmagnetic wall segment (3), in order in this way to achieve optimum trimming of the deflection of the arc.

Abstract: A device for damping thermoacoustic pressure vibrations in a combustion chamber (1), in particular in the combustion chamber of a gas turbine, includes a pressure sensor (6) which is connected to the input of a regulating device (10), the regulating device (10) is connected at its output to a device for electrically controlling the flame in the combustion chamber (1). This device for electrically controlling the flame includes a voltage source (11) and an electrode (14). The electrode (14) is connected to a heat shield (12) which surrounds the outflow side of a burner (3) in an annular manner.

Abstract: A quench cooler for cooling a hot flowing gas essentially comprises a cylindrical shell (10) which is connected to a hot-gas line (7) and to a cold-gas line (9) and which has means (30) for injecting water. The water injection means (30) are pressure-atomization nozzles to which water and steam are admitted. The steam is generated in an evaporator (17) which is arranged in the hot-air line (7).

Abstract: In an airblast atomizer nozzle (2) for the operation of a burner (1) operated with liquid and gaseous fuels (4, 6) the intermediate wall (18) between the inner (14) and outer (13) air duct is held via inner and outer support elements (21) which have a sliding fit (28) and which can be designed as swirl vanes. The atomizer edges (19) of the airblast nozzle (2) are angled in the direction of the nozzle axis (11). The nozzle is distinguished by small dimensions, a low pressure loss and a negligible tendency to coking.

Abstract: The object of the invention is to increase the efficiency of a low-pressure steam turbine connected to a condenser and to reduce its cost of manufacture.According to the invention this is achieved when the dividing plane (8) of the top and bottom part (6, 7) of the outer casing (1) of the low-pressure steam turbine lies at the level of the axis (9) of the turbine rotor (4) and the concrete foundation (14) reaches up to the dividing plane (8). Both the bottom part (7) of the outer casing (1) and the bearing points (10) of the turbine rotor (4) are secured in the concrete foundation (14). The outer casing (1) is designed to be open at least on one side at right angles to and horizontally to the axis (9) of the turbine rotor (4). A condenser (16) is attached to each lateral opening (17) in the outer casing (1).

Abstract: In a device (1) for pressing in slot sealing pieces (12, 14) for winding bars (20) inserted into the slots of a stator laminated core of an electric machine, a plunger (8) is arranged by means of a force-generating device (4) in a collet (2) with a cam (3). The plunger (8) and the cam (3) are situated opposite one another and move toward one another in the fashion of a screw clamp during operation of the force-generating device (4). In this arrangement, when slot sealing pieces are pressed in the cam (3) engages in an axial slit (11) of a first, upper prismatic body (12), and the plunger (8) acts on an end face (13) of a second, lower prismatic body (14). The device (1) for pressing in slot sealing pieces (12, 14) is arranged with lifting devices (22) on a support frame (23) which can be moved along the slot sealing pieces (12, 14) in the stator laminated core.

Abstract: An arrangement for providing exciter current in the rotor of an electric machine. The rotor winding is connected to the slip rings by exciter current conductors which are arranged in pairs in a central shaft bore of the rotor. The slip rings are arranged on a shaft stub which is connected to the rotor shaft with a releasable coupling. The central shaft bore includes bolt-side connection elements into which radially extending current supply bolts are releasably attached. The exciter current conductors are metallic pipes with an orbicular cross-section which are connected permanently at the other end to solid coupling-side connection elements. The ends of the connection elements penetrate a sealing plate in the coupling and are electrically insulated therefrom. Sealing rings are used to seal the sealing plate with respect to the rotor shaft and the ends of the coupling side connection elements which penetrate the sealing plate.

Abstract: A power semiconductor module is specified. It comprises a housing into which any desired power semiconductor circuit is installed. The power semiconductor circuit has at least two connections, which are passed out of the housing. According to the invention, the connections have the form of an elongate plug contact. An insulating plate may additionally be provided between the adjacent plug contacts. Reliable, yet easily releasable, low-inductance electrical contact is achieved by this form of the connections.

Abstract: In a steam generator (1) having, downstream of the fire-box (7), a radiant part and, subsequent thereto, a convective part, the latter essentially comprising, connected in series on the flue-gas side, contact heat exchanger (18), superheater (9) and economizer (2), the steam generator (1) being used in a circuit for the direct selective catalytic reduction (SCR process) of the nitrogen oxides in the flue gas (19), the economizer (2) consists of two parts.

Abstract: Winding bars of AC machines include a multiplicity of mutually electrically insulated conductor elements, which are transposed according to the Roebel principle. The conductor elements in the two end clip sections and in the active part section are transposed with one another.In order to achieve virtually perfect field compensation in the winding overhang, the conductor elements in the two end clip sections have a transposition of between 60.degree. and 120.degree.. In the active part section, either an incomplete transposition is provided, i.e. the transposition in the active part section is uniform and less than 360.degree., or, given a complete 360.degree. transposition in the active part section a void, i.e. a nontransposed section, is provided in the center of the active part, while the transposition in the active part section outside this nontransposed section is a uniform 180.degree. transposition.

Abstract: A multi-pressure waste-heat boiler (7) comprises at least one circulation steam generator, having a low-pressure economizer (15), a low-pressure drum (17) and a low-pressure evaporator (16), and at least one once-through steam generator having a high-pressure economizer (21), a high-pressure evaporator (22) and a high-pressure superheater (23). An oxygen addition (32) is arranged between the steam drum (17) of the circulation steam generator and the high-pressure economizer (21) of the once-through steam generator. An ammonia addition (31) is arranged in the feed line (33) leading to the circulation steam generator.