JPS6099933A - Manufacture of swirler - Google Patents

Abstract

PURPOSE:To prevent separation of inflow air and generation of combustion vibration by a method wherein the blade of the swirler is bent to form it in an axial flow type swirler providing primary air for gas turbine burner or the like with swirl. CONSTITUTION:An inner ring 1, consisting of a short tube having an outer diameter (d), is arranged at the center of the swirler and an outer ring 2, having an inner diameter D and a width H1, is arranged coaxially with the inner ring 1. A plurality of blades 3, whose outside 5 is fixed to said outer ring and whose inside is fixed to the inner ring 1, is arranged between both rings 1, 2. In this case, the number of said blade, the lapping size of the blades and the width of said outer ring are designed from experimental data while the inner diameter of said outer ring and the outflow angle of fluid are designed from design specifications whereby said blades are bent to form them so that the tangential line at the outlet side end of fluid of said blades coincide with the outflow direction of the fluid. The swirler, thus obtained, has a reduced pressure loss resistance of inflow air and disturbance due to separation or the like will never be generated, therefore, a high performance may be developed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing an axial flow swirler that applies swirl to primary air in a gas turbine combustor or the like.

A conventional example of this type of swan is shown in FIG.

In other words, the inner ring 01 and the outer ring 02 are arranged on the same axis, and a plurality of blades 03 are connected between the two wheels. When air flows into the blades, the air flows between the blades 03. The airflow passes through and flows out to the opposite side, but at that time, the airflow is twisted and the direction of the flow changes, causing the airflow to swirl.

However, the above-mentioned conventional swirler has a disadvantage in that the blade o3 is not curved, which causes air to separate, resulting in combustion vibration.

This invention was made in order to eliminate such drawbacks of the conventional swirler. The blade is aligned so that it matches the outflow direction of
The object of the present invention is to provide a method of manufacturing a swirler which eliminates the drawbacks of conventional swans by forming the swirler in a circular manner.

Next, referring to FIG. iii showing an embodiment of the present invention, in FIGS. An inner ring 1 made of a short tube having an outer diameter (1) is arranged in the center of the inner ring, and an outer ring 2 having an inner diameter and a width H1 is set on the same axis as the inner ring. 5 inscribed in the outer ring, and a plurality of blades 3 in which the inner blade 6 is circumscribed in the inner ring.
In this swirler, the projected width of the outer part of the blade is Hl, which is the same as the width of the outer ring, and the projected width of the inner part of the blade is I]2. Now, when the incoming air 4 is sent through the swirler in parallel to its axis, the air becomes outgoing air 4' that is swirled at a certain angle to the axis and is discharged. In addition, 3' indicates a blade adjacent to blade 3,
The outer ring portion wrap distance a between the two blades is empirically determined to be 1.
mm <a <, 3 mm, the inner ring portion wrap distance is similarly l mm≦l) < 3 mm, the number of blades +1 is empirically 12 x n≦30, and the outer ring width H is similarly 10 Since morning≦H1≦70, the equal length A of the outer ring is A-πD/II-a (Figure 4), and the equal length B of the inner ring is B-πφ-b (Figure 4). It will be given to you. Furthermore, if the outflow angle that forces the incoming air 4 to swirl is 01, the sharper the angle, the stronger the swirl.

Next, to explain in detail the manufacture of the swirler described above, the number of blades 3 n1 the width of the outer ring 2 (1, and the lap allowance a of the outer ring part of the blade, and the ramped part of the inner ring part 1) are each determined by the pressure drop resistance of the inflowing air 4. It is given from the flow characteristics and the number of blades, the more the air is swirled with less turbulence, and the outer ring width and the blade wrap width are smaller, the pressure drop resistance is smaller, but the outer ring If the width is too small, the section that gives twist to the air, that is, the run-up distance, will be short and the air will not be able to make a sufficient turn.If the width is too small, the air will not be able to pass through. It is known that the turning becomes insufficient, therefore, the number of blades n, the outer ring portion wrap allowance a, the inner ring portion wrap allowance 1) the paralyzed outer ring width H1 are often of the same value as described above. Furthermore, the inner diameter of the outer ring is determined by the design conditions such as the combustion burner shape, and the shunt outflow angle θ1 is determined by the setting conditions of the swing angle, so each of the above values is set from the crotch specification.5. Next, draw a straight line from point S+ (Fig. 4) on the width line of outer ring 2 in the direction of outflow angle θ, and draw perpendicular lines S and X'.
, and the perpendicular bisector of the straight line 5I82 connecting the point S with the point S2 on the narrow line separated by A+a and the straight line slx.
', and the radius R=XS with the intersection as the center
If we draw an arc of , we can obtain arcs S, S, , with a radius of curvature R. Therefore, the arcs S, S2 become the joining line 5 between the blade 3 and the outer ring 2, and furthermore, on the outer ring width line, a point S is obtained.
A point S3 is defined at a distance A equal to the length A of the outer ring from l, and the intersection point X is determined in the same manner as described above.

An arc 53s4 is drawn with the radius of R around the intersection, and the overlap between the points S2 and s3 becomes the outer ring portion wrap allowance a. Then, points s7 and S8 of equal angle ψ are determined inside the straight line s3x and 54 It is preset in advance.

Therefore, the width H2 of the inner ring 1 is determined from the arc 57s8 (
As shown in Fig. 4) and Fig. 5, points S7 and S8 can be obtained from both the inner ring width ■I2 and the value of B.
If an arc 5788 with radius R is drawn, this arc becomes the joining line 6 between the blade 3 and the inner ring 1, and the height of the blade 3 is D/2-d/2.
Therefore, the outer side of the blade is inscribed in the outer ring 2 and has a curvature like an arc 5I82 (53S4), and the inner side of the blade is inscribed with the inner ring 1 and has a curvature like an arc S7 S8. Become. Therefore, by manufacturing n blades as described above and joining them between the inner and outer rings, a desired swirler can be obtained (FIG. 6).

Therefore, the swirler obtained by the above example is
Since the pressure loss resistance of the inflowing air is small and there is no disturbance due to separation etc., high performance can be achieved. Junction line 5 with 3 (
The arrangement of the arc 51s2) and the joining line 5' (arc 5384) is exactly the same as in the previous embodiment, but the width H2 of the inner ring 1 is determined as described below. That is, the joining line 5'
Assuming that the center of the width H of the first ring coincides with the center of the width H2 of the inner ring, the points s5 and s6 are set so that the straight line P2S is equal to the B+b value obtained in advance (7th point). After obtaining the width H2 of the inner ring l from the arc 55s6 (Fig. 7), as shown in Fig. 8, the inner ring width H
2 and B + ))), and then draw an arc S,, s6 of radius R. This arc is defined by the joining line 6 between the wing s, :3 and the inner ring 1. Therefore, ,
According to the other embodiment described above, in addition to the effects of the embodiment described above, the outer joining line 5' and the inner joining line 6 of the blade 3 are centered, making it easy to manufacture the blade. There are some advantages.

Further, another embodiment of the present invention will be explained with reference to FIGS. 9 and 10. The joining lines 5 and 5' between the outer ring 2 and the blades 3 are determined in exactly the same manner as in the previous embodiment, and the inner ring The width H2 of 1 is determined as follows. That is, parallel lines of width (B+b)/2 are drawn on both sides of the perpendicular bisector of the straight line P3S3 connecting the point P3 of the perpendicular foot to the width line of the outer ring 2 from point s4 and the point s3, and arc 5384 is drawn. The width H2 of the inner ring 1 is determined from the position of the image point after determining the intersection points with the points S9 and SIO, respectively (FIG. 9), and then, in FIG. 10, the same procedure as in the previous two embodiments is The joining line 6 is obtained by drawing an arc 59SlO.

Therefore, according to the further embodiment described above, in addition to the effects of the embodiment described above, the inner side of the blade 3. Since the center of the joining line 6 and the outer joining line 5' are aligned in the outflow direction, there is an effect of reducing the occurrence of turbulence due to flow rate fluctuations.

As mentioned above, this invention has extremely high industrial utility value because the incoming air does not separate, giving the blades a curved shape that does not cause combustion vibration, and making it possible to obtain a swirler with significantly higher performance. .

[Brief explanation of drawings]

FIG. 1 is a perspective view of a conventional axial flow type swirler, FIG. 2 is a longitudinal cross-sectional side view of the swirler according to the present invention, FIG. 3 is a front view thereof, and FIG. 4 is an embodiment of the present invention. Figure 5 is an explanatory diagram showing an example of a method for determining the joining line between the blade and the outer ring and the joining width between the blade and the inner ring. 6 is a plan view of the blade, FIG. 7 is an explanatory diagram showing a method of determining the joining line between the blade and the outer ring and the joining width with the inner ring, showing another embodiment of the invention, and FIG. FIG. 9 is an explanatory diagram illustrating a method for determining the joining line between the blade and the inner ring, and FIG. The explanatory diagram shown in FIG. 10 is also an explanatory diagram showing a method of determining the joining line between the blade and the inner ring. j...Inner ring, 2...Outer ring, 3...Blade, 3'...Adjacent blade, 4...Inflow air, 4'...Outflow air, 5...Blade outside (junction line with outer ring), 5' ...Other feathers 1. (1
111 (joining line), 6... Inner side of blade (joining line with inner ring)
, n... Number of blades, a... Wrap allowance for the outer ring part of the blade, 1
]...Inner ring part wrap distance of the blade, Hl...Width of the outer ring (projected width of the outer part of the blade), H2...Projected width of the inner part of the blade, D...Inner diameter of the outer ring, d...Outside of the inner ring Diameter, θ1: Outflow angle of air. Figure 102 Figure 4 Figure 6 Figure 7 Figure 6 Figure 9

Claims (1)

[Claims] When manufacturing an axial flow swirler in which an inner ring and an outer ring having the same axis are connected via a plurality of blades, the number of blades, the lap width of the blades, and the width of the outer ring are determined based on experience. The inner diameter of the outer ring and the fluid outflow angle are set from the design specifications, and the blade is curved so that the tangent at the fluid outlet side end of the blade coincides with the fluid outflow direction. A method of manufacturing a swara characterized by: