Rotary kinetic fluid motors or pumps – With passage in blade – vane – shaft or rotary distributor...
Reexamination Certificate
1998-12-23
2001-03-06
Verdier, Christopher (Department: 3745)
Rotary kinetic fluid motors or pumps
With passage in blade, vane, shaft or rotary distributor...
C415S116000, C416S095000, C416S09700R
Reexamination Certificate
active
06196791
ABSTRACT:
This application is a national stage application, filed under 35 U.S.C. 371, of International Application No. PCT/JP98/01765, filed Apr. 17, 1998, which claims priority based on Japanese Application No. JP 9-105928, filed Apr. 23, 1997.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a gas turbine cooled moving blade in which a cooling air supply passage, connected to a moving blade, is improved so that temperature elevation and pressure drop of cooling air on the way to the moving blade are suppressed.
2. Description of the Prior Art
FIG. 3
is a cross sectional view showing a prior art air cooled system of a moving blade in a gas turbine inlet portion. In the figure, numeral
21
designates a first stage moving blade, numeral
22
designates a platform thereof, numeral
23
designates a blade root portion and numeral
24
designates a shank portion of a lower portion of the platform
22
. Numeral
31
designates a stationary blade, which is adjacent to the moving blade
21
, numeral
32
designates an inner shroud thereof, numeral
33
designates a cavity in a lower portion of the inner shroud
32
and numeral
34
designates an outer shroud. Numeral
40
designates a rotor disc, numeral
41
designates a disc cavity and numeral
42
designates a radial hole, which is bored in the rotor disc
40
for supplying cooling air therethrough.
The moving blade
21
is arranged alternately with the stationary blade
31
in a rotor axial direction and is fixed to the rotor disc
40
via plural pieces along a rotor circumferential direction, so that the rotor may be driven rotatably due to combustion gas
60
coming from a combustor.
In the gas turbine constructed as above, cooling of the moving blade is achieved by the cooling air, for which a portion of rotor cooling air is used. That is, cooling air
50
flows into the disc cavity
41
and is led into the blade root portion
23
via the radial hole
42
provided in the rotor disc
40
. And then, the cooling air passes through the shank portion
24
and the platform
22
, flows into an air passage (not shown) provided in a blade interior for cooling of the blade and is discharged into a combustion gas passage through a blade surface or a blade trailing edge portion.
In the prior art arrangements cooling for the gas turbine moving blade, cooling air from a rotor cooling system is led from the disc cavity
41
into the air passage for cooling the moving blade through the radial hole
42
, the blade root portion
23
, the shank portion
24
and the platform
22
, as mentioned above. However, as the cooling air
50
is led into the moving blade
21
interior, the cooling air receives heat from the rotor disc etc. so as to become elevated in temperature, and pressure thereof is lowered, so that there occurs a loss until the cooling air is supplied into the air passage in the moving blade
21
. Thus, in order to enhance cooling efficiency, it is necessary to lessen such temperature elevation and pressure loss of the cooling air to the extent possible.
SUMMARY OF THE INVENTION
In view of the problem in the prior art gas turbine cooled moving blade, it is a first object of the present invention to provide an improved gas turbine cooled moving blade in which a cooling air passage is provided for supplying cooling air into a moving blade. Thereby the cooling air is jetted into a lower portion of a moving blade platform from below a stationary blade via a short passage so that temperature elevation is reduced to the extent possible and pressure loss is also reduced resulting in enhanced cooling efficiency.
Further, it is a second object of the present invention to provide an improved gas turbine cooled moving blade, mentioned above, in which the cooling air passage is directed optimally to a rotating moving blade so that the cooling air is jetted at an appropriate velocity so as to be supplied into the moving blade efficiently.
In order to attain the above objects, the present invention provides the following means:
(1) A gas turbine cooled moving blade constructed such that cooling air is led into a moving blade for cooling thereof from a lower portion of a moving blade platform. An air inflow hole is provided in a shank portion of the lower portion of the moving blade platform and a cooling air passage is provided passing through a turbine cylinder wall located below a stationary blade which is adjacent and in front of the moving blade. The cooling air passage is connected at one end to a turbine cylinder and at the other end to a space between the stationary blade and the moving blade. The cooling air is led from the one end and is jetted from the other end toward the air inflow hole so as to flow thereinto.
(2) A gas turbine cooled moving blade as mentioned in (1) above, characterized in that the cooling air passage is formed linearly and is directed to a position which is deviated in a rotational circumferential direction of the air inflow hole by an angle determined by a jetted velocity of the cooling air jetted the said cooling air passage and a rotational velocity of the moving blade from a position of the air inflow hole when the moving blade stands still in a row with the stationary blade in an axial direction of the rotor.
In the invention of (1) above, the cooling air from the turbine cylinder flows into one end of the cooling air passage and is jetted from the other end thereof into the space between the stationary blade and the moving blade toward the air inflow hole provided in the shank portion of the moving blade. The cooling air so jetted reaches the air inflow hole so as to flow thereinto and to be further led into the moving blade for cooling thereof through the shank portion and the platform.
Thus, according to the invention of (1) above, there no need for a radial hole such as that in the prior art as provided in the rotor disc of the moving blade and the cooling air is jetted toward the air inflow hole of the moving blade with the shortest length from below the stationary blade. Thereby ,temperature elevation of the cooling air on the way to the moving blade can be suppressed to a minimum and pressure loss thereof can be also lessened and cooling performance of the moving blade is enhanced.
In the invention of (2) above, the cooling air passage of the invention of (1) above is directed to the position deviated by a predetermined angle in the rotational direction of the moving blade from the position of the air inflow hole at the time when the moving blade stands still, and when the moving blade and thus the air inflow hole rotate. The cooling air is then jetted in the jetted velocity corresponding to the moving velocity of the air inflow hole so that the cooling air reaches the air inflow hole in time, thereby the cooling air can be supplied in the optimal direction while the moving blade rotates and the effect of invention (1) can be enhanced further.
REFERENCES:
patent: 3565545 (1971-02-01), Bobo et al.
patent: 3791758 (1974-02-01), Jenkinson
patent: 3832090 (1974-08-01), Matto
patent: 3873234 (1975-03-01), Penny
patent: 4178129 (1979-12-01), Jenkinson
patent: 4344736 (1982-08-01), Willliamson
patent: 4375891 (1983-03-01), Pask
patent: 4447190 (1984-05-01), Campbell
patent: 4456427 (1984-06-01), Evans et al.
patent: 4807433 (1989-02-01), Maclin et al.
patent: 2054046 (1981-02-01), None
patent: 49-86706 (1974-08-01), None
patent: 50-79610 (1975-06-01), None
patent: 52-34111 (1977-03-01), None
patent: 57-10704 (1982-01-01), None
patent: 3-275946 (1991-12-01), None
patent: 8-177526 (1996-07-01), None
Aoki Sunao
Fukuno Hiroki
Suenaga Kiyoshi
Tomita Yasuoki
Mitsubishi Heavy Industries Ltd.
Verdier Christopher
Wenderoth , Lind & Ponack, L.L.P.
LandOfFree
Gas turbine cooling moving blades does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Gas turbine cooling moving blades, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Gas turbine cooling moving blades will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2478473