JPS58162702A - Axial flow type turbomachine - Google Patents

Abstract

PURPOSE:To provide an axial flow turbomachine adapted to reduce a secondary flow between blades, by having steps formed at side wall surfaces thereof, the surfaces being adjacent to blades at a root side or at a top end of static or moving blades each constructed in an annular configuration. CONSTITUTION:Steps 9, 10 are formed at end wall surfaces of a platform 7 or a shroud 8 of blade 1, the platform 7 and the shroud 8 each being adjacent to each other, and a web 2 of one blade 1 is arranged to be lower than a back face 3 of another adjacent blade. This arrangement can block a secondary flow passing from the web 2 to the back face of another adjacent blade.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to axial flow turbomachines such as steam turbines and gas turbines.

In conventional axial flow turbomachinery, as shown in Fig. 1, at the root or tip of the blade l, in order to balance the pressure of the flow, the ventral surface 2 of each blade also flows to the back surface 3 of the next blade, in addition to the main stream 4. A secondary flow 5 occurs, which causes large losses. In order to prevent this phenomenon from occurring, it has been considered, for example, to specially attach a fence 6 or the like between the blade rows near the root or tip of the blade 1, as shown in FIG. 2.

However, although providing the fence 6 in this way can reduce the secondary flow, the fence 6 must be thick enough not to obstruct the mainstream flow, which poses a problem in terms of strong IW, and the machining process is labor-intensive, resulting in a significant manufacturing cost. Cover up.

SUMMARY OF THE INVENTION An object of the present invention is to provide a trickle turbomachine that reduces the secondary flow of mass, has no problems in terms of strength, and is inexpensive to manufacture.

In order to achieve this object, in the present invention, when single stator blades or single rotor blades are arranged around a rotor and assembled in an annular shape, the base side or the tip side of each stator blade or single rotor blade, or the Steps are formed on the side wall surfaces of adjacent blade units on both sides, so that the ventral surface side of the blade is recessed from the rear side of the adjacent blade.

As a result, it is possible to achieve the same effect as a fence without having to install a special fence between the blade rows.

Hereinafter, embodiments ζ of the present invention will be explained in detail with reference to the drawings in FIGS. 3 to 7.

FIG. 3 is a perspective view of the blade vehicle body, and FIG. 4 is a sectional view taken along the line -IV in FIG. 3. The base 9111 of ll formed with streamlined ventral surface 2 and dorsal surface 3 is a platform 7,
The tip side is a shroud 8.

These blade wheel bodies are assembled in a circular ring around the rotor and arranged as shown in the side view of FIG. That is, a step 9 or 10 is formed on the end wall surfaces of the plant forms 7 or shrouds 8 of adjacent blade vehicle bodies, so that the ventral side of one wing is lower than the back side of the adjacent maple, that is, it is recessed. This makes it possible to block the secondary flow from the ventral side of the wing to the back side of the adjacent wing.

FIG. 6 shows a sectional view taken along the line Vl--Vl in FIG. 5, and the stepped portion 9 or io is straight. In this way, steps can be easily created, and unlike fences, there are no problems with strength (and the construction costs are not high).

In FIG. 5, a step is provided on the end wall 1f]l+ of both the plant form 7 and the juroud 80, but it may be provided only on the tipping force.

FIG. 6 shows a modification of FIG. 5, in which the step 9.100 part is streamlined like the wing surface. In this way, in addition to blocking the secondary flow 5, it is also possible to direct the flow exclusively in the direction of the main stream 4, thereby further improving the turbine efficiency.

[Brief explanation of drawings]

1 and 2 are plan views showing flow conditions in the blades of two conventional types of trickle turbomachines, FIG. 3 is a perspective view of the blade vehicle body, and FIG. 4 is the line N-- in FIG. 3. 5 is a side view showing the assembled state of the wing according to the present invention; FIG. 6 is a sectional view taken along line Vl-W in FIG. 5;
The figure is a sectional view of a modification of FIG. 6. 1... wing, 2... wing ventral surface, 3... wing back surface, 4... main stream,
5-@Secondary flow, 6...Fence, 7--Plant form, 8...7 u7ud, 9.10...Step. Akira 1 Figures 1 and 2 Figure 3 Figure 5 Procedural amendment C spontaneously] July 21, 1981 [1 Special +? '+-Mr. Kazuo Wakasugi, Commissioner of the Agency+ 1) Indication of fl Patent application 1982 44471
2. Name of the invention Axial flow turbomachinery: (Relationship with the case) Name of applicant Mitsubishi Heavy Industries, Ltd. 4th representative (ko166) Tadashi Kimura
J5, Amendment A, 11th month, Showa year
The description in the "Brief explanation of drawings" column will be corrected as follows. (1) For page 4, line 1, F, figure 6, correct 1 in figure 5 to read ``Figure 7 is in figure 6.'' (2) Page 4, lines 11-12 [line Vl-Vl in Figure 5]
Cross-sectional view along 1m 1 is corrected as [cross-sectional view near the platform or shroud in Figure 5].

Claims (1)

[Claims] An axial-flow turbomachinery characterized by a step that blocks the secondary flow toward the back side of the blade, which is assembled in an annular shape around a single rotor.