RU2577678C1 - High-speed turbine generator with low-power steam drive - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: invention relates to power engineering and can be used in independent power electric power plants (up to 100 kW). High-speed turbine-generator equipped with low-power steam drive consists of flow part comprising turbine impeller with blades, vanes of turbine, electric generator. Turbine generator contains double turbine bearing installed rigidly and electric generator bearing installed flexibly. Turbine generator contains combined cooling system, consisting of stator liquid cooling jacket made in form of spiral channels, and air cooling system of stator and rotor of electric generator.

EFFECT: reduced friction in bearings of shaft of turbine generator at initial stage of starting, bi-lateral fixing of shaft axial displacement, improving cooling efficiency, increased reliability of operation of bearings, higher efficiency of turbine generator and reliability of electric generator.

4 cl, 8 dwg

Description

The invention relates to the field of power engineering and can be used in stand-alone power plants of low electrical power (up to 100 kW).

Known, for example, a steam turbine company "Turbopar" (http://www.turbopar.ru) low power (100-250 kW), designed to utilize excess steam energy from a steam boiler and consisting of a housing, a stop valve, an electric generator, a rotor which is located on the same shaft with the impeller of the turbine.

The disadvantage of this turbogenerator is the large mass and dimensions, which are due to the relatively small number of revolutions of the rotor of the generator - 3000 rpm

Known low-power turbogenerator (100 kW) Elliott TA-100 (http://stc-mtt.ru/publication). This is a high-speed single-shaft unit with a rotor speed of 68,000 rpm. Structurally, it is made in a single housing in which an electric generator is installed, the rotor of which with four permanent magnets is pressed onto the shaft. Along with its direct purpose - the production of electricity, an electric generator is also used as a starter at the initial stage of launch. A shaft with wheels of a centrifugal compressor and a centripetal turbine, fixed by friction welding, is installed in the stator of the electric generator on two supports. The first support is an angular contact rolling bearing with ceramic balls, the second is a hydrodynamic plain bearing. For forced cooling of the stator, as well as for cooling and lubricating both bearings, the turbogenerator is equipped with a special lubrication system. The turbogenerator has a combustion chamber, the combustion products of which are the working fluid of the turbine.

A disadvantage of the known turbogenerator is:

- design complexity;

- a large moment of resistance to rotation of the shaft at the moment of its moving away from a stationary state, created by hydrodynamic sliding bearings, the steel petals of which are pressed to the surface of the shaft, slide along its support in the dry friction mode (without lubrication), which requires the transfer of the generator at the initial start-up moment to starter mode and complications of the turbogenerator start-up program;

- a gas-fired combustion chamber is potentially explosive;

- single-row ceramic ball bearing perceives radial and bilateral axial loads, which reduces its reliability;

- the oil cooling system of the elements of the turbogenerator itself is equipped with an air cooling system for its oil radiator, and in the presence of a high-temperature combustion chamber it is also fire hazardous.

The prototype of the invention is a turbine generator of a centripetal wet-steam turbine (RF patent No. 134239), having a vertical design and consisting of a housing (main turbine housing and an electric generator housing), a stator and a rotor mounted therein on gas-dynamic sliding bearings, a flow part, consisting of a nozzle apparatus and from working blades (blades) located on the impeller of the turbine mounted on the cantilever section of the shaft, as well as the condenser, hermetically connected in a single design.

The disadvantages of the turbine generator of a centripetal wet-steam turbine are:

- a large moment of resistance to rotation of the shaft created by the frictional forces arising when the elastic lobes of two radial gas-dynamic sliding bearings are pressed against the neck of the shaft and to the two end surfaces of the thrust bearing heel at the time of moving the shaft from a stationary state at start-up, necessitates the use of a turbogenerator starter start;

- the petals of gas-dynamic bearings at the initial stage of launch (up to 10,000 rpm) are subject to intense friction, which leads to a decrease in the reliability of their operation during repeated starts of the turbogenerator;

- insufficient efficiency of liquid cooling of the generator with straight channels in its housing and the absence of an air cooling system.

The objective of the invention is to provide a reliable high-speed turbogenerator with a steam drive of low power to generate electrical energy up to 100 kW, not requiring a starter start.

The technical result of the proposed high-speed turbogenerator with a steam drive of low power is:

- reduction of friction forces in the bearings of the shaft of the turbogenerator at the initial stage of the launch as a result of replacing three gas-dynamic sliding bearings with two ceramic rolling bearings: a twin turbine bearing, consisting of two angular contact closed ball bearings with grease and a radial ball bearing with ball bearings lubricated ceramic ball bearing of the generator, which reduces the moment of resistance of the friction forces to the rotation of the shaft of the turbogenerator and creates the conditions for it ezstarternogo run;

- fixing on both sides of the axial displacement of the shaft of the turbogenerator by ensuring a fixed position of the turbine bearing in the housing, and the shaft of the turbogenerator relative to the bearing, due to which the minimum labyrinth clearances between the back side of the turbine impeller and the turbine and turbine bearings are kept constant, which in turn minimizes steam leakage past the turbine impeller blades;

- increasing the cooling efficiency of the electric generator through the use of a combined - liquid and air cooling system;

- improving the reliability of the bearings of the turbogenerator due to unloading from the differential pressure of the turbine bearing and the mobility of the bearing of the generator in the housing;

- increasing the efficiency of the turbogenerator and the reliability of the generator due to, accordingly, eliminating steam leaks past the blades of the turbine impeller and into the region of the current-carrying elements of the generator.

The technical result of the invention is achieved by:

- a high-speed turbo-generator with a low-power steam drive, consisting of a flow part, including a turbine impeller with blades mounted on it, a turbine nozzle apparatus, an electric generator, a twin turbine bearing installed in the housing motionless, and an electric generator bearing mounted in the housing movably, in addition contains a combined cooling system;

- a high-speed turbo generator with a low-power steam drive, including a combined electric generator cooling system, consisting of a stator liquid cooling jacket made in the form of spiral channels, and an air stator cooling system and an electric generator rotor, including a centrifugal ventilation impeller;

- a high-speed turbine generator with a low-power steam drive, containing a vacuum chamber connected through an annular gap formed by the surfaces of the turbine bearing housings and the intermediate turbine housing and connected on one side through annular labyrinth seals between the surfaces of the shaft sleeve and the turbine bearing housing and the back of the turbine impeller with an annular chamber under the turbine bearing, and on the other hand connected through labyrinth seals between the back of the working ring the turbine and the intermediate turbine casing with an annular gap between the outer diameter of the turbine impeller and the turbine nozzle apparatus.

In turn, the vacuum chamber through the output communicated with the vacuum pump;

- a high-speed turbogenerator with a low-power steam drive, in which vertical and horizontal channels are made in the turbine bearing housing.

In FIG. 1 shows a longitudinal section through a high-speed turbo-generator with a low-power steam drive; FIG. 2 is a view A of a high speed turbo generator with a low power steam drive, FIG. 3 is a transverse section bB, in FIG. 4 is a cross-sectional view BB, in FIG. 5 is a transverse section GG, in FIG. 6 is a cross-sectional view of DD, in FIG. 7 - remote element AE, in FIG. 8 is a prototype of the invention as part of a mini cogeneration power plant.

A high-speed turbogenerator (up to 40 thousand revolutions per minute) with a low-power steam drive consists (Fig. 1) of a turbine generator shaft 1, on which are installed: a turbine impeller 2 with blades 3, an electric generator rotor 4, rigidly mounted on a centrifugal ventilation turbogenerator shaft impellers 5 of the air cooling system, shaft sleeve 6, speed sensor disk 7 and turbine generator shaft speed sensor 8. In addition, a high-speed low-power steam turbine generator also contains and a pair 9, a steam manifold 10, a nozzle apparatus of a turbine 11, a main turbine housing 12, an intermediate turbine housing 13, a turbine bearing housing 14 in which a twin turbine 15 bearing is installed (Fig. 1 and Fig. 7), consisting of two radially thrust ceramic angular contact ball bearings sealed with grease (hereinafter referred to as “turbine bearing”). The bearing of the turbine 15 is fixed from axial movement along the shaft on one side of the centrifugal ventilation impeller 5, and on the other hand, by the shaft sleeve 6 (Fig. 7). In turn, the movement of the bearings of the turbine 15 together with the shaft of the turbogenerator 1 in the axial direction is limited on one side by a stop cap 16, which is bolted 17 to the intermediate housing of the turbine 13, and on the other hand by a protrusion in the bearing housing of the turbine 14, which ensures (guarantees) invariability the gap during operation of the turbogenerator between the rear side of the impeller of the turbine 2, on the one hand, and the intermediate housing of the turbine 13 and the bearing housing of the turbine 14, on the other hand.

An electric generator (not shown in FIG.) Of a high-speed turbo-generator with a low-power steam drive includes (Fig. 1) an electric generator housing 18 with a cover for the electric generator 19. On the outer side surface of the electric generator 18 there is a liquid cooling jacket 20 made in the form of spiral channels trapezoidal or rectangular thread, two annular chambers 21 and 22 with the inlet fitting 23 and the outlet pipe 24 of the coolant. A stator (not indicated) of a power generator consisting of a core of the stator 25, a coil 26 and the terminals of the phases 27 is fixedly mounted in the housing of the generator 18.

In the housing cover of the generator 19 is located the bearing housing of the generator 28, in which on the outer surface of the outer ring in a sliding fit there is a radial ceramic ball bearing of the electric generator closed with grease (hereinafter referred to as the “generator generator”) 29. On the inner surface of the inner ring, the generator bearing 29 is mounted on transition landing on the shaft of the turbogenerator 1.

On top of the housing of the electric generator 18, a cover of the speed sensor of the shaft of the turbogenerator 30 is installed. In the cover of the sensor of the speed of the shaft of the turbogenerator 30 there are radial holes 31 (Fig. 1, Fig. 3) designed to allow air to flow outside into the chamber 32. Through holes 33 in the housing the bearing of the generator 28, the chamber 32 is connected to the flow chamber 34. In addition, through the holes 35 (Fig. 2 and Fig. 3) in the flange (not shown in Fig.) of the cover of the speed sensor of the shaft of the turbogenerator 30, as well as in the cover of the generator body 19 (FIG. 1, Fig. 2, Fig. 3) the flow chamber 34 is connected to the environment. In turn, the flow chamber 34 through the axial grooves 36 in the stator and rotor of the generator is connected with the flow chamber 37 (Fig. 1, Fig. 4).

The flow chamber 37 through the openings 38 (Fig. 1) communicates with the environment, and through the vertical channels 39 (Fig. 1, Fig. 5, Fig. 6 and Fig. 7) and the horizontal channels 40 (Fig. 1, Fig. 6 and Fig. 7) communicates with the annular chamber 41 under the bearing of the turbine 15. In turn, the annular chamber 41 (Fig. 1. Fig. 7) under the housing of the turbine 14 through the annular labyrinth seal 42 between the shaft sleeve 6 and the turbine bearing housing 14 and then through the labyrinth seal 43 between the back of the impeller of the turbine 2 and the bearing housing of the turbine 14, through the ring the gap 44 between the bearing housing of the turbine 14 and the intermediate housing of the turbine 13 is in communication with the vacuum chamber 45. In turn, the vacuum chamber 45 through the output 46 (Fig. 6) is in communication with a vacuum pump (Fig. not shown). The vacuum chamber 45 through the annular gap 44 (Fig. 7) is also connected through a labyrinth seal 47 between the rear side of the impeller of the turbine 2 and the intermediate casing of the turbine 13 with an annular gap 48 (Fig. 7) between the outer diameter of the impeller of the turbine 2 and the nozzle apparatus of the turbine eleven.

The appearance of the turbogenerator is shown in FIG. 8 (item 49) as part of a mini-cogeneration power plant.

High-speed turbogenerator with a steam drive of low power operates as follows.

Steam is supplied from the boiler (Fig. 1) through the steam inlet pipe 9 to the steam collector 10, from where, flowing through the nozzle apparatus of the turbine 11 and expanding between the blades 3 of the impeller of the turbine 2, as a result of changing the momentum, the steam stream creates a torque exceeding the moment the resistance created by the bearings of the turbine 15 and the bearing of the generator 29.

After straggling from the stationary state of the shaft of the turbogenerator 1 (together with the impeller of the turbine 2 and the rotor of the electric generator 4), its speed increases and the electric generator (not shown) is turned on, which transmits an electric current through the outputs of phases 27 to the output inverter - voltage converter (not indicated in FIG.). The frequency of rotation of the shaft of the turbogenerator 1 is controlled by the speed sensor of the shaft 8, in the coils of which the drive of the speed sensor 7 induces an electromotive force proportional to its speed of rotation.

The steam spent on the blades 3 of the impeller of the turbine 2 is sent to a receiving condenser (not indicated in Fig.), After which the condensate can be used for technological needs or in the heating system.

The operation of the turbogenerator is accompanied by the appearance on the shaft of the turbogenerator 1 of alternating axial loads, which are perceived by the bearing of the turbine 15, in which each of the angular contact bearings perceives axial loads in mutually opposite directions.

When an axial load occurs on the shaft of the turbogenerator 1, for example, upwardly, the force through the shaft sleeve 6, the turbine bearing 15, the thrust cover 16 and bolts 17 is transmitted to the intermediate turbine housing 13. The axial force of the opposite direction is transmitted from top to bottom to the intermediate turbine housing 13 the shaft of the turbogenerator 1 through a rigidly mounted centrifugal fan impeller 5 of the air cooling system, the bearing of the turbine 15 and through the bearing housing of the turbine 14 is also transmitted to the intermediate housing urbines 13. Thus, the power flows from axial loads occurring on the shaft of the turbogenerator 1 are closed by means of the bearing of the turbine 15 on the intermediate casing of the turbine 13, and through it on the main casing of the turbine 12 and the casing of the electric generator 18, as a result of which the shaft of the turbine generator 1 is fixed from axial movements.

Radial loads acting on the shaft of the turbogenerator 1 are perceived by both the bearing of the turbine 15 and the bearing of the generator 29, which, being movable in the bearing housing of the generator 28, with temperature changes in the length of the shaft of the turbogenerator 1 moves freely (without jamming) in the axial direction and only radial loads.

During operation of the generator in the core of the rotor of the generator 4, the core of the stator 25 and the coil 26, a significant amount of thermal energy is released, which is selected by the combined cooling system - liquid and air.

In a liquid cooling system of an electric generator, a cooling liquid, for example water, under pressure from an external source enters through an inlet fitting 23 into an annular chamber 21, from where it moves along the spiral channels of a liquid cooling jacket 20 of the stator and from an annular chamber 22 enters into an outlet fitting 24. Due to the use of the cooling system of the spiral channels increases the intensity of convective heat transfer by increasing the heat transfer coefficient in the spiral channels. In addition, as a result of the increase in the heat transfer area in the spiral channels compared to the straight channels, the amount of heat taken from the core of the stator 25 and the coil 26 of the electric generator increases.

An additional intensification of heat transfer is provided by an air cooling system, the operation of which is as follows. The centrifugal impeller 5 of the air cooling system during rotation of the shaft of the turbogenerator 1 expels air from the flow chamber 37 through the openings 38 in the lower part of the housing of the generator 18 (Fig. 1 and Fig. 5) to the outside. Moreover, in the flow chamber 37 creates a vacuum with a pressure p _in , due to which, under the influence of a differential pressure (Δp = p _atm- p _in ), air initially enters from the outside through the radial holes 31 in the cover of the sensor of the rotational speed of the turbogenerator shaft 30 (Fig. 1 and Fig. 3) into the chamber 32, from where through the holes 33 in the bearing housing of the electric generator 28 to the flow chamber 34. Along with this, the air also enters the flow chamber 34 from the outside through the openings 35 (Fig. 2, Fig. 3) in the flange of the number sensor cover revolutions of the shaft of the turbogenerator 30 and the housing cover lektrogeneratora 19 (FIG. 1 and FIG. 3). Air flows from the flow chamber 34 along axial grooves 36 in the stator and rotor of the electric generator, through the gaps between the windings of the stator coil 26 (Fig. 4), from where it enters the flow chamber 37. Flowing along axial grooves 36 in the stator and rotor of the electric generator, the air stream cools the stator core 25 and the rotor of the electric generator 4.

After cooling the electric generator (not shown in FIG.), Air flows out of the flow chamber 37 through openings 38 into the environment. At the same time, from the flow chamber 37 through the vertical channels 39 and horizontal channels 40 (Fig. 1 and Fig. 7), air enters the annular chamber 41 under the bearing of the turbine 15, as a result of which the pressures in the cavities of the flow chamber 37 and the annular chamber 41 are equalized, therefore the cuffs of the bearing of the turbine 15 are unloaded from the differential pressure of air, which guarantees the safety of grease in the bearing of the turbine 15, thereby increasing the reliability and service life of the bearing of the turbine 15.

Air under the influence of rarefaction (Fig. 6, Fig. 7) created by the vacuum pump in the vacuum chamber 45, moves from the annular chamber 41 through the annular labyrinth seal 42, the labyrinth seal 43 and enters the vacuum chamber 45 through the annular gap 44. Such a path of movement air eliminates its flow to the blades 3 of the impeller of the turbine 2, which eliminates steam leakage past the blades 3 of the impeller of the turbine 2, and thereby increases the efficiency of the turbine. In turn, the steam from the annular gap 48 formed between the outer diameter of the impeller of the turbine 2 and the nozzle apparatus of the turbine 11 through the labyrinth seal 47, restricting the leakage of steam, moves into the annular gap 44, from where it enters the vacuum chamber 45 together with air, which eliminates steam entering the flow chamber 37 to the current-carrying elements of the electric generator. From the vacuum chamber 45 by means of a vacuum pump, the air-vapor mixture is aspirated in the direction of arrow A through terminal 46 (Fig. 6) into the atmosphere.

The claimed objectives and technical result can be achieved by manufacturing the invention according to the drawings shown in FIG. 1-7, with subsequent testing and implementation of the invention into operation. To date, a prototype of a turbogenerator has been manufactured and passed preliminary tests as part of a mini-cogeneration power plant (see Fig. 8, item 49).

Claims (4)

1. A high-speed turbo-generator with a low-power steam drive, consisting of a flowing part including a turbine impeller with blades mounted on it, a turbine nozzle apparatus, an electric generator, characterized in that it comprises a coupled turbine bearing mounted in the housing stationary and an electric generator bearing installed in the case it is movable, besides it contains a combined cooling system. 2. A high-speed turbogenerator with a low-power steam drive according to claim 1, comprising a combined electric generator cooling system, consisting of a stator liquid cooling jacket made in the form of spiral channels, and an air stator cooling system and an electric generator rotor, including a centrifugal ventilation impeller. 3. High-speed turbogenerator with a low-power steam drive according to claim 1, characterized in that it contains a vacuum chamber connected through an annular gap formed by the surfaces of the turbine bearing housings and the intermediate turbine housing, and connected on one side through an annular labyrinth seal between the surfaces of the shaft sleeve and a bearing housing and a labyrinth seal between the intermediate turbine housing and the rear side of the turbine impeller with an annular chamber under the turbine bearing, and on the other hand connected through a labyrinth seal between the rear side of the turbine impeller and the intermediate turbine casing with an annular gap between the outer diameter of the turbine impeller and the turbine nozzle apparatus, and, in addition, the vacuum chamber is connected to the vacuum pump via an outlet. 4. High-speed turbogenerator with a low-power steam drive according to claim 1, characterized in that the vertical and horizontal channels are made in the turbine bearing housing.

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