GB2073825A

GB2073825A - Turbine installation comprising a turbine installed in a duct

Info

Publication number: GB2073825A
Application number: GB8110841A
Authority: GB
Original assignee: Voestalpine AG
Current assignee: Voestalpine AG
Priority date: 1980-04-16
Filing date: 1981-04-07
Publication date: 1981-10-21
Also published as: AR225952A1; ATA204380A; JPS56162271A; IN155635B; AT364967B; MX152685A; GB2073825B; EP0038321B1; DE3160807D1; CA1139185A; BR8102280A; ES501205A0; TR20682A; ES8204071A1; JPS6349074B2; PL230671A1; MY8500632A; EP0038321A1

Description

1 GB 2 073 825 A 1

SPECIFICATION Turbine installation comprising a turbine installed in a duct

This invention relates to a turbine installation comprising flow passage-defining means defining an inlet chamber and a runner chamber and including two juxtaposed pipelines which connect the inlet chamber and the runner chamber and are disposed on opposite sides of an axial center plane and spaced apart in an intermediate part of their length, a turbine runner rotatably mounted in said runner chamber, an electric generator disposed outside the flow passage-defining means, and an output mechanism extending through the space between the two pipelines and operatively 80 connecting the runner to the generator.

In conventional turbine installations comprising a turbine installed in a duct, the runner and the generator constitute a central section, which is enclosed in a housing that is anchored in the duct 85 by means of radial arms and the interior of which can be walked in for assembling and repair work.

In these structures, one of the radial arms is hollow and serves as an access shaft. Whereas that design has proved quite satisfactory in large turbine installations comprising a turbine installed in a duct, the access to the central section becomes increasingly difficult as the size of the machine is decreased. For this reason that design of turbine installations comprising a turbine installed in a duct is not suitable for medium and small size installations.

In another construction, which is known from German Patent Specification 912,320, only the turbine runner is mounted in a center section housing and the generator is accommodated in a hollow shaft, which extends through the duct and divides it into two flow passages. As the hollow shaft itself occupies a relatively large space, the access to the generator through the hollow shaft 105 will also be difficult if the design is to be adopted for medium-size and small turbine installations comprising a turbine mounted in a duct. If the generator is disposed outside the duct and operatively connected to the turbine runner by level gear train, the generator will be easily accessible but the access to the level gear train accommodated in the hollow shaft will be difficult.

According to the present invention there is provided a turbine installation comprising:

flow passage-defining means that comprise two juxtaposed interconnecting passages spaced apart in an intermediate part of their length to define a space between them, an inlet chamber having an outlet communicating with each of said 120 interconnecting passages and a runner chamber having an inlet communicating with each of said interconnecting passages and a runner chamber having an inlet communicating with each of said interconnecting passages, a turbine runner mounted in said runner chamber forrotation on a fixed axis, an electric generator disposed outside said flow passage-defining means, and an output mechanism which extends through said space and operatively connects said runner to said generator, said two pipelines being disposed on opposite sides of an imaginary plane which contains said axis, characterised in that said interconnecting passages are defined by two pipelines, each of which is composed of a plurality of straight pipe sections and has a cross-section that is substantially the same as that part of the crosssection of said inlet chamber at said outlet which is disposed on the same side of said plane.as the respective pipeline, said pipelines converge to form a junction near said inlet of said runner chamber, a carrying tube is provided, which is centred on said axis and extends through and is sealed in both said pipelines adjacent to said junction and protrudes into said space, and said output mechanism comprises a turbine shaft that is mounted in said carrying tube for rotation on said axis and non-rotatably connected to said runner.

Because the driving water is fed to the runner chamber in two spaced apart pipelines, each of which consists of a plurality of straight pipe sections, the two pipelines define between them a space which is easily accessible and in which-the drive means for controlling the turbine can be accommodated and through which the output mechanism connected to the turbine may extend. Even though that space is relatively small, it is easily accessible because there is no hollow shaft that extends through the flow passage but the driving water is fed to the turbine runner in two pipelines, each of which consists of a plurality of pipe sections. The total cross-section of these two pipelines is substantially the same as the crosssection of the inlet chamber at its outlet so that the conditions of flow are not greatly altered by the fact that the flow passage is divided into two pipelines, particularly because only a small diversion of flow is required by the division into two pipelines. The space between the two pipelines need not be large because it is easily accessible.

The two pipelines can easily be manufactured because they are composed each of a plurality of straight pipe sections so that the generatrices consist of straight lines. The pipelines can be connected to the inlet chamber without need for complicated and expensive junction fittings. This is due to the fact that the cross-section of each pipe section is substantially the same as that part of the cross-section of the inlet chamber at its outlet which is left free by the respective oiher pipeline so that the total cross-section of the two pipelines is. substantially the same as the cross section of the inlet chamber at its outlet. As the inlet chamber is generally defined by a pipe which is circular in cross- section so that its cross-section at its outlet will also be circular, the pipelines will be semicircular in cross-section. In that case, the pipe sections for the two pipelines can be made in 2 GB 2 073 825 A 2 that circular-section pipes are bisected along axial planes.

Because the total cross-section remains the same adjacent to the two pipelines and the flow is only slightly diverted, such design can be used also for installations having high inlet velocities and operating under high pressures so that such turbine installations comprising a turbine installed in a duct can be used also where the heads are large. Besides, the installation can easily be installed in exciting pipelines because it will be sufficient to replace part of that pipeline by the flow passage-defining means of the turbine installation.

Particularly simple conditions are ensured by the provision of the tube which carries the turbine shaft because that carrying tube reduces the cross-section of flow for the driving water so that the latter is a ccelerated in the desired manner before entering the runner chamber.

The carrying tube acts to stiffen the confronting planar walls of the two pipelines in the region in which the driving water is accelerated. Further downstream, the carrying tube tends to reduce the turbulence of the water flowing to the runner wheel. Although the carrying tube is straight, favourable conditions of flow can be ensured because the carrying tube does not terminate in the interior of the flow passagedefining means and for this reason need not be streamlined. Besides, the carrying tube, which extends through the flow passages defined by the converging end portions of the two pipelines near the runner chamber, permits the provision of a simple mechanism which operatively connects the generator and the runner because the turbine shaft which extends out of the carrying tube into the space between the pipelines is freely accessible. A bevel gear train may be arranged in the space between the pipelines and may be used 105 to establish an operative connection to the generator, which may be supported by the two pipelines. The bevel gear train may be replaced by a belt drive, which connects the turbine shaft to the generator shaft.

If the diameter of the carrying tube is as large as the largest distance between the two pipelines, this will permit a particularly advantageous utilization of space, on the one hand, and the provision of a particularly stiff structure, on the other hand.

To ensure that all parts of the structure which may require to be serviced will be readily accessible, the interlor of the carrying tube communicates with the interior of the flow 120 passage defining means so that the required seal against the driving water is effected at the point where the turbine shaft emerges from that end of the carrying tube which protrudes into the space between the pipelines. That seal is effected in the 125 usual manner by a stuffing box, which in that arrangement is accessible from the space between the two pipelines. Because the carrying tube is filled with driving water, the driving water cannot be contaminated from the carrying tube. 130 This fact is of essential significance for turbine installations installed in drinking water mains. Any leakage water can enter the space between the two pipelines only through the stuffing box but this is no problem.

If the interior of the flow passage-defining means communicates with the interior of the carrying tube, a contamination of the driving water by the means by which the turbine shaft is supported in the carrying tube must be prevented. If the turbine shaft is supported in the carrying tube by a water-lubricated rubber bearing, a contamination by lubricating oil will be prevented. Besides, the water which fills the carrying tube will then act as an emergency lubricant if the separate supply of water to the rubber bearing should fail.

The invention will be more fully understood from the embodiments described below by way of example only with reference to the several figures of the accompanying drawings, in which:- Figure 1 is a view in oblique perspective showing flow passage-defining means of a turbine installation embodying the invention and comprising a turbine installed in a duct; Figure 2 is a longitudinal axial part sectional view showing such a turbine installation comprising a turbine installed in a duct; Figure 3 is a cross-sectional view taken on section station 111-111 of Figure 2; Figure 4 is a side elevation (in the direction of arrow IV in Figure 5) showing a modified turbine installation embodying the invention; Figure 5 is a sectional view taken on section station V-V of Figure 4; and Figure 6 is a longitudinal and part sectional view showing another modified turbine installation embodying the invention.

Referring now to the figures of the drawing in Figure 1, flow passage-defining means shown generally at 1 has an inlet chamber 2 of circular cross-section and comprise two pipelines 4, 42 which extend and divide from the inlet chamber 2 and are disposed on opposite sides of an axial center plane (a, b, c, d) and define between them a free space 3. The pipelines 41, 42 converge to form a junction at a runner feedpipe 5, which leads to a runner chamber P that is followed in the line of flow by a diffuser 7. The runner feedpipe 5 has at its inlet end 51 a circular cross-section, which is substantially the same as the circular crosssection of the inlet chamber 2 at its outlet 2, The inlet chamber 2 is defined by a pipe. Because each of the pipelines 41, 4, is composed of straight pipe sections that are semicircular in cross-section and have a total cross-seGtion that is substantially the same as the cross-section of the inlet chamber 2 at its inlet and the cross-section of the runner feed pipe 5 at its inlet 5, the two pipelines 41, 4, can easily be connected to the outlet opening 21 of the inlet chamber 2 and to the inlet opening 5, of the runner feed pipe 5. Each of the pipelines 4 is virtually the result of a dichotomy of the inlet chamber.

A turbine runner 8 is mounted upstream in a carrying tube 9, that extends through and is sealed 3 GB 2 073 825 A 3 in pipelines 4 in end portions thereof which converge to a junction at the runner feed pipe 5.

The carrying tube 9 protrudes into the free space 3 between the two pipelines 4, 42. To show clearly how the interpenetration of the carrying tube 9 70 and the inner walls 101, 102 of the pipelines 41, 4, is effected a part 421 and 51 of the outer wall of one pipeline 42 and of the runner feed pipe 5, is shown detached. Clearly the pipelines 41, 42 define between them the free space 3 that is freely accessible and in which parts of the structure that may require to be serviced can be accommodated. This will hardly restrict the des ign of the mechanism by which the runner 8 is operatively connected to a generator because the 80 carrying tube 9 and the turbine shaft protrude into that free space 3. Although the output mechanism connected to the turbine and the control mechanism for controlling the turbine can be accommodated in the free space 3 so that said mechanisms can easily be serviced, there will be favourable conditions of flow so that such turbine installations can be used also wherever relatively high inlet velocities and high pressures are encountered. Because the diversion of flow is small and the cross-sections of flow remain substantially constant as far as to the carrying tube 9, it may be expected that the conditions will remain substantially constant in a major part of the length of the two pipelines 4, 4, Only adjacent to the junction of the two pipelines 41, 42 95 before the runner feed-pipe 5 is the cross-section of flow decreased by the carrying tube 9; this will result in a desired acceleration of the driving water before it enters the runner chamber 6.

In Figure 2 where thesame reference numbers 100 are used to denote similar integers to those of Figure 1 turbine shaft 12 carrying runner 8 is mounted in carrying tube 9 in a water-lubricated rubber bearing 13, placed near the runner 81. The turbine shaft 12 is supported at one end by the 105 water-lubricated rubber bearing 13 and its other end by a bevel gear train in a housing 17, The interior of the carrying tube 9 is sealed, against the driving water, by a stuffing box 14, comprising a labyrinth seal disposed at that end of the carrying 110 tube 9 that is remote from the runner 8. As a result, the carrying tube 9 is filled with the driving water and the stuffing box 14 is accessible from the free space 3 between the two pipelines 4, 4, For this reason the stuffing box 14 can be serviced 115 even during operation. The mechanism by which the runner 8 is operatively connected to an electric generator 15 comprises turbine shaft 12 and a rigid coupling 16 connecting the said turbine shaft 12 to the bevel gear train (not shown) in a housing 120 indicated by numeral 171. An output shaft 17, of that bevel gear train is connected by a flexible coupling 18 to a shaft 19 of the generator 15 that is carried by a bracket 20, that spans the free space 3 and is supported by the pipelines 41, 4, 125 The bevel gear train 17, may be mounted on crossbeams 2 1, that connect the pipelines 41, 4, and hold them spaced apart. Control motors for controlling the turbine may be accommodated in the free space 3. One of such control motors is indicated at 22.

In Figures 2 and 3 the center plane a, b, c, d between the two pipelines 4, 4, is substantially vertical so that the genertor shaft 19 is also substantially vertical but as shown in Figures 4 and 5 it may be substantially horizontal. The electric generator 15 may then be additionally supported by a foundation 23. The bracket 20 may be omitted.

In Figure 6 the flow passage-defining means 1 is inclined. The shaft 19 of the generator is parallel to the turbine shaft 12 and is connected to it by a belt drive 24. In other respects the turbine installation shown in Figure 6 is similar to that of Figure 1 but particularly suitable for turbine installations of small and medium size.

The turbine used in any embodiment above may have adjustable runner blades, adjustable guide vanes or adjustable runner blades and guide vanes may also be used as is well understood by those skilled in the turbine art.

Claims

1. A turbine installation comprising:

flow passage-defining means that comprise two juxtaposed interconnecting passages spaced apart in an intermediate part of their length to define a space between them, an inlet chamber having an outlet communicating with each of said interconnecting passages and a runner chamber having an inlet communicating with each of said interconnecting passages, a turbine runner mounted in said runner chamber for rotation on a fixed axis, an electric generator disposed outside said flow passage-defining means, and an electric generator disposed outside said flow passage-defining means, and an output mechanism which extends through said space and operatively connects said runner to said generator, said two pipelines being disposed on opposite sides of an imaginary plane which contains said axis, characterised in that said interconnecting passages are defined by two pipelines, each of which is composed of a plurality of straight pipe sections and has a cross-section that is substantially the same as that part of the cross section of said inlet chamber at said outlet which is disposed on the same side of said plane as the respective pipeline, said pipelines converge to form a junction near said inlet of said runner chamber, a carrying tube is provided, which is centered on said axis and extends through and is sedled in both said pipelines adjacent to said junction and protrudes into said space, and said output mechanism comprises a turbine shaft that is mounted in said carrying tube for rotation on said axis and non-rotatably connected to said runner.

2. The installation as claimed in claim 1, wherein the diameter of said carrying tube equals 4 GB 2 073 825 A 4 the largest distance between said pipelines..

3. The installation as claimed in claim 1, wherein the interior of said carrying tube communicates with the interior of said flow 5 passage-defining means.

4. The installation as claimed in claim 3, wherein said carrying tube contains a waterlubricated rubber bearing, in which said turbine shaft is rotatably mounted.

5. A turbine installation constructed and arranged to operate substantially as hereinbefore described and as shown in Figures 1, 2 and 3 of the accompanying drawings.

6. A turbine installation constructed and arranged to operate substantially as hereinbefore described and as shown in Figures 4 and 5 of the accompanying drawings.

7. A turbine installation constructed and arranged to operate substantially as hereinbefore described and as shown in Figure 6 of the accompanying drawings.

Printed for Her Majesty's Stationery Office by the Courier Press, Leamington Spa, 1981. Published by the Patent Office, 25 Southampton Buildings, London, WC2A lAY, from which copies may be obtained.