JPS58167808A - Mixed pressure turbine - Google Patents

Abstract

PURPOSE:To obtain a flow uniform with respect to the tengential direction in order to reduce fluid loss by forming a peripheral flow passage in connection to a low-pressure supply pipe of a mixed pressure turbine and by installing a fluid control member serving as a fluid guide at an entrance part of this peripheral flow passage. CONSTITUTION:A peripheral flow passage 5 is formed in connection to a low- pressure supply pipe 3, while a member 12 that is used concurrently as a guide for the secondary working fluid is formed bent in an arc shape at an entrance part 5b of the peripheral flow passage 5. Owing to the member 12, the secondary working fluid is separated uniformly to join later the primary working fluid passing through a flow passage 11.

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention relates to a mixed pressure turbine (also referred to as a mixed pressure turbine) Kid used in a geothermal turbine plant, in particular, to reduce fatigue of rotor blades in this mixed pressure turbine. Relating to a damage prevention device.

[Technical background of the invention]

This type of mixed-pressure turbine, which has already been proposed, mainly supplies high-pressure/secondary working fluid to the first stage and supplies low-pressure primary working fluid to the middle stage, in order to improve power generation efficiency in geothermal turbine plants. It is configured to supply

That is, the above-mentioned mixed pressure turbine that has already been proposed has a first
As shown in the figure and No. JIlIK, the turbine casing/flc/high pressure supply pipe (high pressure steam supply pipe) J into which the secondary working fluid flows and the low pressure supply pipe (J) into which the secondary working fluid flows
Low pressure steam supply pipe) J is installed.

A plurality of silent blades are formed in the turbine passage ll of the turbine casing located in the inner circumferential flow passages e and jK, respectively, to form respective muddy flow passages e and j that communicate with the high pressure supply pipe J and the low pressure supply pipe J, respectively. 7.1. The stator blades 4.7. The blades 10a of the rotor shaft IO are arranged in the turbine casing at positions t and f, and the blades 10a of the rotor shaft IO are arranged at a distance of Km so as to be able to rotate.

Therefore, the above-mentioned high-pressure turbine has the above-mentioned high-pressure supply pipe.
The working fluid in the form of high-pressure steam flowing from the turbidity flow path to each of the stator vanes j, 7. #, f rotates the blades 10 & of the rotor shaft 10 while flowing out from the circumferential passage j to the stator vanes l, j [K].

The blades lN10m of the rotor shaft io are rotated.

1 Special K, the above/next working fluid and the above second working fluid are formed at the outlet (outflow part) s*lc of the above-mentioned muddy flow path j, and while merging at the above-mentioned turbine flow path ll of the 9th turbine middle stage section. , as shown in FIG. 1, it flows out in the circumferential direction.

[Problems with background technology]

However, the above-mentioned mixed pressure turbine has a muddy flow path formed on the outside of the turbine passage.

Therefore, a portion of the upper secondary fluid as low-pressure steam is stored as 9IL1. Although the flow is biased in the circumferential direction, most of the quaternary working fluid is communicated with the low pressure supply pipe 3 and flows through the nine circumferential flow path j.
As a result, after the above/next working fluid and the next working fluid join together, these combined working fluids flow extremely non-uniformly in the circumferential direction. In the middle stage of the turbine where the non-uniform converging working fluid flows in, the pupil loss due to turbulence in the bridge of body #1 increases, but the fluid excitation force acts on the blade 10IL of the rotor shaft 10. , there is a risk of fatigue failure.
L-turbine efficiency is reduced and there is a problem in reliability for long-term continuous operation.

[Purpose of the invention]

The present invention was made in view of the above-mentioned circumstances! Therefore, a fluid control member that also serves as a fluid guide is attached to the inlet of the turbid flow path that communicates with the low pressure supply pipe of the turbine casing to generate a uniform flow in the circumferential direction and reduce various fluid losses. The present invention provides a mixed pressure turbine that aims to prevent the generation of fluid excitation force, and at the same time, improve turbine efficiency and improve reliability for long-term operation.

[Summary of the invention]

Particularly, one aspect of the present invention is to provide a turbine casing with a high-pressure supply pipe into which a secondary working fluid flows and a low-pressure supply pipe into which a primary working fluid flows, and to communicate with the low-pressure supply pipe to form a turbid flow path. It is constructed by providing a fluid control member that also serves as a fluid guide at the entrance of the turbid flow path.

[Embodiments of the invention]

The present invention will be described below with reference to an illustrated embodiment.

Table 1 The present invention will be described by assigning the same reference numerals to the same constituent members as in the above-mentioned circular embodiment.

In FIGS. 1 to 5, reference numeral 1 denotes a turbine casing, and this turbine casing has a high-pressure supply pipe 3 into which the working fluid flows and a low-pressure supply pipe 3 into which the working fluid flows. The low pressure supply pipe 3 and the low pressure supply pipe 3 are provided with flow passages Q and j communicating therewith. In addition, a plurality of stationary blades 4.7. They are arranged concentrically in the order of # and de, and each of these @4.7.1. The blade 101L of the rotor shaft IO is arranged in the turbine casing l where f is located. Further, at the inlet portion 5b of the turbid flow path j communicating with the low pressure supply pipe J, a fluid control member/co which also serves as a fluid guide for the next working fluid is formed in a curved arc shape. The relationship between the maximum width of the fluid control member l and the maximum width of the inlet part jt+ of the turbid flow path j is developed and shown in FIG.

It is desirable that the structure be configured such that IL"J + L, L position > Ll - However, Ll indicates the minimum width of the inlet part jll of the turbid flow path j, and The maximum width wA'Ik is formed near the inlet jb of the circumferential flow path 5).

It is formed to become narrower as it moves away from the low pressure supply pipe J. The flow path of the primary working fluid flowing from the low-pressure supply pipe 3 is formed to be narrow at the entrance portion jb of the turbid flow path j, and to become wider as it moves away from the low-pressure supply pipe 3.

Therefore, the 1 inflow from the queen high pressure supply pipe according to the present invention
The next working fluid rotates the blades 10a of the rotor shaft 10 while flowing out from the muddy channel to the stator vanes 4.7, l, and d, while the primary working fluid as low pressure steam Although it flows from the low-pressure supply pipe into the turbidity flow path J, the flow is uniform due to the fluid control member /J attached to the inlet of this turbidity flow path J) K which also serves as a companion fluid guide, and the flow is uniform in the circumferential direction. The above 7 flows through the turbine flow path //l while turning Km.
In this way, the primary working fluid flowing through the muddy flow path jKk is uniformly divided by the upper mud body control member l- so that it merges with the next working fluid and rotates the blade 10a of the rotor shaft 10. , the working fluid flows through the turbine flow path // and works by merging with the above/next working fluid, so it is possible to prevent losses caused by fi body vortices and i flows, and also to prevent fatigue damage caused by fluid excitation force. Harmful effects can be prevented.

Next, the embodiment shown in FIG. 1 is another example of the present invention, in which a fluid control member/co' is integrally formed at the inlet part jb of the MI flow path j. This has the same inner tube as the specific example described above.

The embodiment shown in FIG. 7 is another embodiment of the present invention, in which the turbine casing/is provided with a low-pressure supply 'IJ on the stiffness, and each inlet section j of the turbid flow path j communicating therewith is provided.
P is attached with a fluid control member/J on the stiffness,
This is the same content as the specific example described above. - Furthermore, the embodiment shown in FIG. 1 is another embodiment of the present invention, which includes fluid control members l! representing each pair of inlets jbK of the turbid flow path S communicating with the low-pressure supply pipe J. It is designed to separate the primary working fluid, and has the same configuration as the specific example described above.

The embodiment shown in FIG. 9 and FIG. A nine flow system member I made of copper material is provided, which allows the primary working fluid to be uniformly divided into turbine flow paths /l/l.
This makes it possible to merge with the next working fluid.

Furthermore, the embodiments shown in Fig. 1/ and Fig. 1-
This is another embodiment of the present invention, in which a fluid control member "l" composed of a large number of pins forming a density is provided at the entrance part j'kl of the turbid flow path S communicating with the low pressure supply pipe 3. As a result, the second working fluid can be uniformly divided and merged with the second working fluid in the turbine flow path/l to perform work.

The graph shown in Figure IS shows the circumferential distribution of the muddy flow path j by making the experimental result K dimensionless using the average value Vm. At point P near the low-pressure supply pipe 3 (inlet part), the velocity of the primary working fluid is approximately - times the average value.
On the other hand, at point Q, which is the farthest position from the low-pressure supply pipe 3, almost no inflow occurs and the distribution is non-uniform in one circumferential direction.

On the other hand, in the present invention, as shown by the curved edge l, the inflow velocity is uniform in the circular direction. Next, the graph shown in Fig.
4, which shows the total pressure loss ζ of the flow at 61.111
Curve #1m is a conventional mixed pressure turbine, and Curve 1a is according to the present invention. Therefore, as is clear from this graph, the total pressure loss in the conventional type is extremely large. This is because the primary working fluid flows non-uniformly in the circumferential direction and disturbs the main flow. In contrast, in the present invention.

- Next, the working fluid flows uniformly in the circumferential direction.

〔Effect of the invention〕

As described above, according to the present invention, the high pressure supply pipe 3 into which the working fluid flows into the turbine casing and the low pressure supply pipe 3 into which the working fluid flows into the turbine casing are provided.
The inlet part j of this side channel j is connected to form both channels 5.
Since a fluid control member (l) which also serves as a fluid guide is provided at (b), it is possible not only to prevent an increase in total pressure loss due to non-uniformity of flow, but also to prevent the occurrence of fluid vibration. , the reliability for long-term operation is improved, and since the configuration is simple, it can be provided at low cost.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a part of a mixed pressure turbine that has already been proposed, FIG. 1 is a longitudinal sectional view taken along the dashed line in FIG. 7, and FIG. FIG. 9 is a cross-sectional view showing a part of the pressure turbine, and FIG. 5 is a longitudinal cross-sectional view taken along the chain line IV-mV in FIG. 3. Developed views of the fluid control member incorporated in the present invention, and FIGS. 4 to 7 are views showing other Ovl embodiments of the present invention. Figure 1J and Figure 1 are graphs showing the inflow velocity of the J-th working fluid.
...Low pressure supply pipe, j...Both channels, 4.7. r, W.
...Stator blade, 10...Rotor shaft, I-co...Fluid control member. To the applicant's agent Kiyoshi Inomata - Figure 1 Figure 350 Figure 15 Figure 6 Figure 7 Figure 8 Figure 9 Figure 11

Claims (1)

[Claims] 1. A high pressure supply pipe into which the secondary working fluid flows and a low pressure supply pipe into which the primary working fluid flows are provided in the turbine casing,
A mixed pressure turbine characterized in that a turbid flow path is formed in communication with the low pressure supply pipe, and a fluid control member that also serves as a fluid guide is provided at the entrance of the turbid flow path. (h) The O mixed pressure turbine according to claim 7, wherein the fluid control member is curved in an arc shape. J, install a low pressure supply pipe higher than the turbine casing KJ,
The O mixed pressure turbine according to claim 7 or 1, characterized in that a fluid control member may be attached at each inlet portion KJ or higher of the muddy flow path communicating with these. Pavilion, entrance part of the muddy channel K11l! The mixed pressure turbine according to claim 1, 2 or 3, characterized in that a fluid control member made of steel or a large number of bottles can be installed in the IF.