SU1149135A1 - Microturbine directing apparatus investigating stand - Google Patents

Abstract

STAND FOR RESEARCH guide apparatus microturbine comprising a housing placed therein investigational guide apparatus spun mL guide krshchatku, konsolnr mounted on the shaft, located in the gas bearings and connected to a lever that interacts with measuring scales, characterized in that, in order to increase the accuracy of the study in determining the moment of the amount of motion acting on the device under study, by eliminating gas leaks, the alignment impeller is provided with a toroid-cylindrical shell, With a gap relative to the housing, it has an axial hole, and in the case, in the exit zone, there is a spacing (the left head plate is annular from: the chamber and a source of high pressure gas is connected to it.

Description

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WITH

WITH

The invention relates to test stands, namely, test stands for the study of low-output steam and gas turbine guides or turbo-expanders. A stand for examining microturbine guiding apparatus is known, containing the guiding apparatus under study, fixedly mounted in housing J and directing the impeller associated with swinging in bearings bearing shaft 5 which is kept in supporting state outer lever. ÜDICH devices with a blade height of 26 mm выс In this case, part of the air passes, in addition to the spreading needle, into the gap between the casing and the impeller and does not give the moment, which introduces an error in the deotenie ef ciency. At significant heights of guide vanes and small zaragla the magnitude of the error is small, with decreasing blade sizes, the age error The closest to the invention to the technical essence and achieves the result is a stand for microturbine guide apparatuses, comprising a housing spaced in it. spraying apparatus, spraying impeller j mounted on the shaft, located in the gas supports and connected to the lever, which interacts with the measuring weight ami 2.

A disadvantage of the known test bench is that a part of the gas released from the guide vane does not enter the spraying impeller, but leaks through the gaps between, the casing and the spraying impeller. Due to the presence of the indicated leaks, a systematic error appears in determining the moment of the amount of movement, the flow after it leaves the guiding apparatus.

This error, CHiiKaeT, is an accuracy of determining the effectiveness of a guiding apparatus; it is especially great (up to 100%) when testing microturbine guiding apparatus, the flow area of which soposta ™

The spraying impeller 4 is mounted on a shaft 7 located in gas supports 8 and connected to a lever 9 interacting with measuring scales 10 fixing the moment of amount of movement acting on the apparatus under study 3. A labyrinth seal 11 is installed between the impeller 4 and gas supports 8 The torocylindrical shell 6 is installed with a gap 12 relative to the flange 2 of the housing 1, in which an annular chamber 13 is made in the exit zone of the spraying impeller .4 and a high-pressure gas source is connected to it (not yet en) connected to the housing 1. The system 5 with area of gaps between the housing and the guide vane ml spr "The aim of the invention increase the accuracy in determining the study of angular momentum dvi7keni 5 acting on the monitoring apparatus by eliminating gas leaks. This goal is achieved by the fact that, in a test bench, a microturbine guide1-1x apparatus, comprising a housing, an exploration guide1 apparatus located in it, which retracts the impeller, mounted on a Baxiyj located in gas supports and connected to an arm the balancer impeller is equipped with a torto-cylindrical shellJ located with a gap relative to the housing j and has an axial extrusion, and in the housing in the exit zone of the regulating impeller there is an annular chamber and A high pressure gas source is connected to it. Fig. 1 shows the layout of the test bench for the direction of microturbine apparatus; fig. 2, displacing impeller; fig, 3 section. in FIG. 2; FIG. 4, view B in FIG. 2 (without torus-cylindrical shell), FIG. 5 shows the dependence of the angle of exit of the flow from the impeller; Stand containing body 1 with detachable flange 2, housed in housing 1, the guiding device 3 under investigation, mounted on removable flange 2 of housing 1, fixing Krishchatka 4 with radial blades 5, on which the torocylinder shell 6 is fixed.

3

14 communications with regulating valves consisting of a valve 15 for supplying the working gas to the guide ™ apparatus 3, valve 16 for supplying pressurized gas to the annular chamber 13 on the code from the spraying impeller 4 and valve 17 for supplying the pressure gas to the annular pressure in the annular chamber 18 for the labyrinth seal 11, and also contains the flow rate of measures 19, instrumentation 20 for determining pressure and temperature at the inlet of the stand gauge 21 for measuring the pressure behind the guide vane 3 and differential pressure gauges 22 and 23 for monitoring zero differential pressure in the gap 12 between the detachable flange 2 of the housing 1 and the torocylindrical shell 6. The distributor impeller 4, as well as in the gap 24 between the housing 1 and the back side of the impeller 4 connected to the differential pressure gauge 23 pulse holes 25, Similarly, the gap. 12 is connected to a pulse pressure sensor 22 and apertures 26,

The annular chambers 13 and 18 of the pressurized gas supply are connected to the gaps 12 and 24, respectively.

The spraying impeller 4 (Fig. 2) has the number Z of the radial blades .5, The radial vanes 5 have an outer diameter d and a length B and are located at a distance of a step t from one another (Fig. 3)

 In order to avoid the influence of the ends of the radial blades 5 on the readings of the differential pressure gauge 22, the pulse holes 25 are located at a distance of & 0.2 length In the radial blade 5 of the spinning impeller 4 from its ends (Fig. 1).

The gas flow coming out of the radial blades 5 cpp from the impeller .4 has an exit angle o4 (Fig 4)

In order to avoid systematic errors associated with the presence of swirling flow on the inlet of the spinning impeller 4, the flow at the outlet of the spinning impeller must: have an axial direction j i. angle Ci, 90 °.

491354

In order for the direction of flow of the entrance to the radial blades 5 not to affect the axial output, the ratio of the blade pitch t to their B should not be more than 0.3; and the ratio of the length of the blades b to their outer diameter d is not less than 10, / Z,

This is confirmed by the experimental graph (Fig. 5) 5 in which 10 shows the change in the magnitude of the flow out angle (, 2 from the ratio B to i,

When the number of blades and the ratio B / d approaching 2, the flow direction becomes axial (o, 90 °),

The stand works as follows.

When high pressure gas is supplied (fig. 1, not shown), shaft 7 is weighed on supports 20 and 8 with spraying impeller 4 fixed on it. Then, through valve 15, flow meter 19 and P13 measuring instruments 20, the working gas is supplied to guiding apparatus under test 3

High pressure gas is supplied to the annular chambers 13 and 18 through the valves 15 and 17 until zero pressure drop is established in the impulse ports 25 and 26, measuring differential diameters 22 and 23,

When a zero pressure drop is reached in the outer holes 25 and 26, as evidenced by the zero readings of the differential pressure gauges 22 and 23, the moment of movement is measured using a measuring scale of 10 °.

Measurement of the momentum quantity at zero differential pressure allows to eliminate the systematic error J caused by the presence of leaks.

As shown by the tests carried out on the proposed stand, the elimination of this error makes it possible to increase the accuracy of determining the efficiency of the guide devices for each turbine from 20 to 100%, depending on the size of the flow sections of the guide vehicles.

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Claims (1)

STAND FOR RESEARCH OF GUIDING DEVICES OF MICROTURBINES, containing a housing, an investigated guide apparatus placed therein, a straightening impeller, cantilever mounted on a shaft located in gas supports and connected to a lever interacting with a measuring scale, characterized in that, in order to improve accuracy studies when determining the moment of momentum acting on the apparatus under study by eliminating gas leaks, the straightening impeller is equipped with a torocylindrical shell located minutes with a clearance relative to the housing and has an axial outlet and a housing in the exit region of the impeller is formed of rectifier ', annular chamber and connected to it a source of high pressure gas. 1149-135