RU2307940C2 - Wet steam reaction turbine - Google Patents

Abstract

FIELD: mechanical engineering; turbines.

SUBSTANCE: proposed reaction turbine for wet steam has housing accommodating hollow rotor fitted on shaft and made in form of at least one disk with system of distributing channels, all communicating with space of rotor and connected on periphery with de Laval nozzles. Axes of de Laval nozzles are arranged tangentially. Rear walls of distributing channels are made in form of penetrable partitions separating distributing channels from condensate collecting chambers. Condensate collecting chambers communicate with ring chamber of disk with fitted-in condensate outlet pipes whose inlet holes are arranged square to direction of disk rotation. Pipes are connected with condensate outlet line.

EFFECT: increased service life and reliability of reaction turbine operating on wet steam or "wet" gas owing to elimination of erosion of nozzle walls.

5 cl, 2 dwg

Description

The invention relates to the field of turbine construction, mainly to turbines operating on wet steam and "raw" natural gas, and can be used in steam and gas turbomachines to drive electric generators, compressors, pumps.

Known dual-flow radial-axial turbines containing a radial nozzle apparatus with a flow separator and axial blade crowns between which there is a chamber with a separating ridge on the rotor, while the cavity of the flow separator communicates with the cavity of the chamber by means of an annular gap provided with side visors bent into the cavity of the separator (USSR author's certificate No. 901584, class F01D 25/32, 1982). The specified device provides for the removal of condensate in front of the working crowns due to the presence of a hollow separator flows in communication with the cavity of the chamber.

The disadvantages of the known device is the complexity of its design and insufficiently high separation efficiency. In addition, this device provides efficient operation only when using wet steam as a working fluid. When working on wet steam or "raw" gas, the device will not provide effective separation of condensate and solid particles, since the conditions for their directed separation are not created.

Also known are jet turbines containing a housing in which a working element of the Segner wheel type with tangentially mounted nozzles is placed (US Patent No. 3032988, CL 60-39.35, 1962). The impeller of the device is made in the form of a hollow drum, closed at the ends of two disks.

The specified design of the turbine when operating on a two-phase flow provides efficient condensate separation due to the original design of the impeller. However, it does not provide for the removal of condensate from the separation zone, as a result of which the separated condensate in the form of droplets is repeatedly reflected from one turbine blade to another, causing their erosion. In the process of droplet recirculation, they become larger and condensate accumulates in the cavity of the impeller.

A jet turbine for a two-phase flow is also known, comprising a housing and a rotor, on the hollow shaft of which an impeller is installed in the form of a system of curved radial channels communicating with the shaft cavity, in the outlet sections of which, bent in the tangential direction relative to the circumference of the impeller, Laval nozzles are installed ( GDR Economic Patent No. 213973, CL F01D 1/32, 1984).

However, in the specified device at the constructive level, the separation of the separated condensate is not organized, as a result of which the nozzles and the walls of the sections of the channels adjacent to the nozzles are eroded.

Of the known turbines, the closest to the proposed one is a jet turbine for a multiphase working fluid (RF Patent No. 2086774, class F01D 1/32, F01D 25/32, 1997), in which an impeller is installed on the hollow shaft in the form of a disk with a curved channel system communicating with the cavity of the shaft. The output sections of the channels are bent in a tangential direction relative to the circumference of the impeller and are connected to Laval nozzles. The outlet sections of the channels have additional diversion separation channels with drain openings blocked by check valves. The separated condensate is collected in the bypass separation channels and then discharged from the impeller through valves and drain holes.

The disadvantages of the above device: in fact, the Coriolis acceleration action arising from the movement of liquid particles in the radial direction is not actually used for separation purposes; Valves in operation are affected by significant centrifugal forces directed normally to the surfaces of their movable contact, which causes asymmetrically directed friction forces and increases the necessary stopping forces, reducing the degree of sensitivity of the valves as a column of separated condensate; the degree of increase in the level of condensate over the various valves is not the same, which causes the impeller mass unbalance and, as a result, an additional cause of turbine vibration.

The purpose of the present invention: the creation of the design of a jet turbine, providing when working on wet steam or "raw" gas, the elimination of erosion of the walls of the nozzles and, thus, increasing the reliability and resource of the turbine.

This goal is achieved by the fact that in a jet turbine for wet steam (gas) containing a housing, a shaft and a hollow rotor in the form of at least one disk, the rotor has a system of dispensing channels connecting the rotor cavity with Laval nozzles, which are placed tangentially on the periphery of the rotor. The walls of the distribution channels that are rear in relation to the direction of rotation are made in the form of permeable partitions separating the distribution channels from the condensate collection chambers. The zones of the chambers that are farthest in the direction of the radii communicate with the annular chamber of the disk with condensate drain pipes installed in it, the inlet openings of which are located normally to the direction of rotation of the disk. The tubes are connected to the condensate drain line from the turbine.

Condensation is separated from wet steam in the distribution channels under the influence of Coriolis acceleration, which occurs when liquid particles move in the radial direction. The separated condensate is collected by the condensate collection chambers and discharged into the annular disk chamber, from which the condensate drain pipes are discharged from the turbine to the condensate drain line.

In a preferred embodiment: the distribution channels are located at an acute angle relative to the axes of the nozzles; the cross section of the dispensing channels has a rectangular shape and is located so that the large side of the rectangle is parallel to the axis of the rotor; the cross section of the nozzles is rectangular; permeable partitions are made in the form of blinds, the plates of which are installed in the distribution channels at an acute angle towards the steam flow.

In Fig.1 the device is depicted in the form of an axial section aa in Fig.2; figure 2 presents the transverse sections BB and BB in figure 1.

The turbine contains a housing 1 with a pipe 2 for exhaust steam. In the housing 1, a rotor is installed on the shaft 3, consisting of one or several disks 4 having a central channel 5 connected by distributing channels 6 with tangentially located Laval nozzles 7. The rear wall (taking into account the direction of rotation of the rotor 4) of the channel 6 is made in the form of a permeable partition 8, separating the channel 6 from the condensate collection chamber 9. The most distant along the radius (peripheral) part of the chamber 9 through the hole 10 communicates with the cavity of the annular chamber 11 of the disk 4. Inside the chamber 11 is fixed relative to the housing 1 condensate discharge tubes 12, the ends of which are bent so that their inlet openings are normal to the direction of rotation of the disk. The tubes 12 are connected to the condensate drain line 13 from the turbine.

The rotor is installed in the housing 1 by means of bearings 14 and is equipped with seals 15.

The housing 1 is equipped with a steam pipe 16, constantly in communication with the Central channel 5 of the rotor 4.

The operation of the turbine is based on the reactive action of 7 jets of the steam (gas) stream flowing out of the nozzles.

The working fluid in the form of wet steam or "raw" natural gas is supplied under pressure through the pipe 16, the Central channel 5 and the distribution channels 6 to the nozzles 7 and expire them. The torque created at the same time on the rotor and shaft 3 drives the consumer of mechanical work into rotation: an electric generator, compressor, pump or other unit.

In the dispensing channels 6, the condensate contained in wet steam or natural gas under the action of forces due to Coriolis acceleration is discarded to the permeable walls 8 and passes from the channels 6 into the condensate collection chambers 9 and accumulates in its peripheral part. As condensate accumulates in the chambers 9, it is discharged into the cavity of the annular chamber 11, then through the condensate drain pipes 12 to the condensate drain line 13. In this case, the movement of the condensate is caused, firstly, by the action of the pressure differential between the chambers 9 and the outlet from the line 13, and secondly, by the action of the high-speed pressure of the condensate having an angular velocity of the rotor relative to the stationary tubes 12.

The location of the dispensing channels 6 at an acute angle relative to the axes of the nozzles 7 leads to the fact that the Coriolis acceleration vector is directed normally (with small deviations from the normal) towards the permeable partitions 8. In addition, in the case of choosing the cross-sectional shape of the channels 6 in the form of a rectangle with an arrangement so that the large side of the rectangle is parallel to the axis of the rotor, minimizing the length of the trajectory of the movement of liquid particles to the permeable septum 8. These two factors contribute to an effective and practical lnoy separation of liquid particles and move them into the condensate collecting chamber 9.

The condensate under the action of centrifugal forces is located inside the annular chamber 11 in the form of a liquid ring, the thickness of which is identical at all points around the circumference. This results in a lack of rotor unbalance and causes turbine vibrations.

Laval nozzles 7 can be made with a classic round cross-section, ensuring their maximum intrinsic efficiency. However, the variant in which the nozzles 7 are made with a rectangular cross-sectional shape makes it possible to reduce the length of the transitional part of the channel 6 while reducing aerodynamic losses in it, optimizing the efficiency of the "channel 6 - nozzle 7" system, and also to simplify the manufacturing technology of the disk 4 as a whole.

Permeable partitions 8 are made in the form of grids.

In the embodiment of the permeable partitions 8 in the form of blinds, the plates of which are installed at an acute angle to the flow of steam, the capture of liquid particles by the plates of the blinds and the additional effect of the high-pressure head of the steam flow in channel 6 on the flow of droplets from channels 6 to chambers 9 are achieved.

The casing and disks of the turbine can be made by known technologies using both foundry and welding joints of stamped molds from sheet sections, which is more preferable and economical for the adopted configurations.

The proposed design of the turbine due to the increased resource and relatively low cost of manufacture can find application in the power industry and in the fields of gas condensate fields as a turbo-throttle to reduce pressure while at the same time generating electric pressure differential with its subsequent use.

Claims (4)

1. Jet turbine for wet steam, comprising a housing in which a hollow rotor is mounted on the shaft in the form of at least one disk with a system of dispensing channels communicating with the rotor cavity and connected at the periphery with Laval nozzles, the axes of which are tangentially different the fact that the rear walls of the distribution channels are made in the form of permeable partitions separating the distribution channels from the condensate collection chambers, which communicate with the annular disk chamber with the condensate drain tubes installed in it, Stia which are arranged normal to the direction of rotation of the disk, and the tube connected to the condensate discharge line. 2. The jet turbine according to claim 1, characterized in that the distribution channels are located at an acute angle relative to the axes of the nozzles. 3. The jet turbine according to claim 1, characterized in that the permeable partitions are made in the form of blinds, the plates of which are installed at an acute angle towards the flow of steam. 4. The jet turbine according to claim 1, characterized in that the cross section of the distribution channels is rectangular in shape and is located so that the greater side of the channel is parallel to the axis of the rotor.

Images