JPS59153901A - Cooling device for rotor in steam turbine - Google Patents

Abstract

PURPOSE:To aim at enhancing the effect of cooling, by arranging auxiliary movable blades along the outer periphery of a rotor in opposite to auxiliary stationary blades laid on a partition member defining a counter inflow chamber so that the outer periphery of the rotor is cooled down by the steam which has passed through the auxiliary movable blades. CONSTITUTION:Auxiliary movable blades 46 are arranged along the outer periphery of a rotor 40 in opposite to auxiliary stationary blades 44 arranged on the intermediate section of a partition member 43 which divides a steam inflow chamber into a main steam inflow chamber 14a and a counter steam inflow chamber 14b. The steam which is introduced in the counter inflow chamber 14b works through the auxiliary movable blades 46, and thereafter, flows along the counter inflow chamber 14b around the outer periphery of the rotor 40. With this arrangement, the outer surface of the rotor 40 may be maintained at a low temperature.

Description

[Detailed description of the invention] The present invention relates to a cooling device for a partial steam turbine rotor.

In general, the working fluid of a steam turbine is required to be heated to a higher temperature at the inlet in order to improve the efficiency of the thermal cycle, and the higher temperature working fluid is injected within the allowable range of the high temperature strength of the turbine rotor material. In order to avoid this problem, a method is used to cool the surface of the turbine rotor at a portion where the high temperature working fluid flows in with a lower temperature working fluid, and there is a need for a simpler cooling device that is not affected by the thermal cycle of the working fluid.

FIG. 1 shows a conventional embodiment, and is a vertical cross-sectional view of a main part of a high-humidity steam inlet chamber of a double-flow steam turbine. In the figure, 11' indicates a first-stage stator blade, 12 indicates a second-stage stator blade, 11 indicates a first-stage moving blade, and 12 indicates a second-stage moving blade. In each stage, a number of stator blades 11', 12' and 11;
Ill and 12 are attached to the turbine rotor 1o, and a shroud (not shown) is provided at the tip of the blade.

Reference numeral 13 denotes an annular partition member, which is provided between the fourteenth stationary blades 11', sandwiching the high-temperature steam inflow chamber 14, and covers the outer periphery of the turbine rotor 10 at the portion into which the high-temperature steam flows. The high-temperature steam enters the inlet chamber 14 from the inlet 15, is divided in the direction of arrow 16, and passes through the stationary blades 11' and the rotor blades 11 in sequence, generating torque that rotates the turbine rotor 1°. 17 is a pipe through which cooling fluid flows, and an inlet 15 for high temperature steam.
The cooling fluid is inserted into the partition wall member 13 from above, so that cooling fluid flows through the gap between the partition wall member 13 and the turbine rotor 10 in the direction of arrow 18. Therefore, the area where high-temperature steam flows is
The surface of the turbine rotor 10 is cooled, allowing the inflow of higher temperature steam within the allowable range of the high temperature strength of the turbine rotor. However, this method requires a piping system for the cooling fluid, which complicates the structure, and has the disadvantage of causing energy loss due to changes in the thermal cycle and mixing of high and low temperature fluids.

FIG. 2 shows another conventional example 1a, which is a longitudinal cross-sectional view of a main part of a high-temperature steam inlet chamber of a single-flow steam turbine.

In the figure, 20' is a stator blade holder, and 20 is a butter turbine rotor, and the stator blade holder 20' has a first stage stator blade 21' and a first stage moving blade 21 on one side with a high temperature steam inlet 25 in between. the second stage static R22'' and the second stage rotor blade 2 on the other hand.
2 and later are arranged. High temperature steam flows from inlet 25 to 2
6, the flow passes from the first stage stator blade 21' to the first stage rotor blade 21 via the shielding cover 23, and the shaft seal provided between the turbine rotor 20 and the stator vane holder 20'. The steam is reversed in the direction of arrow 27 by the device 24, and the steam whose temperature has been lowered is guided to the second and subsequent stages of blades. This avoids direct contact of hot steam with the surface of the turbine rotor 20. However, this method has the disadvantage that fluid pressure loss occurs due to the complexity of the flow path.

FIG. 3 shows another conventional embodiment, in which (a,)
2 shows a vertical cross section of the main part of the high temperature steam inlet chamber of a double flow steam turbine, and FIG. In the figure, the same components as those shown in FIG. 1 are given the same reference numerals and their explanations will be omitted. The high-temperature steam enters the inlet chamber 14 from the inlet 15, and a part of it is guided to the jet nozzle 34 provided at an angle on the partition wall member 33. From the jet nozzle 34, the steam flows in the direction of rotation of the turbine rotor 10 in the direction of arrow 35. It is arranged so that it flows out along the outer peripheral surface of the turbine rotor. Further, the steam is given a swirling speed that is the same as or faster than the circumferential speed of the turbine rotor, and the temperature of the fluid between the partition wall member 33 and the turbine rotor 10 is lowered by a throttling effect and a temperature corresponding to this speed energy. A method is known for cooling the surface of the turbine rotor 10 by cooling the surface of the turbine rotor 10.

However, with this method, the temperature reduction effect is limited by the circumferential speed of the turbine rotor, and at the same time, when the swirling speed of the fluid decreases due to friction loss, the velocity energy is regenerated into heat. The disadvantage is that the energy returned increases the temperature of the fluid and reduces the cooling effect.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the above-mentioned drawbacks and provide a steam turbine rotor cooling device that is simpler in terms of ffji and has a large cooling effect that is not affected by the thermal cycle of the working fluid.

According to the present invention, the above object is achieved by forming an annular steam inflow chamber into a main steam inflow chamber on the outer diameter side and a subgroup air inflow chamber on the inner diameter side by an annular partition member supported on the fixed part side of the inflow chamber. radial-type auxiliary stator vanes are disposed within the partition wall member to communicate between the auxiliary stator vanes to direct cooling steam for the turbine rotor from the main steam inflow chamber to the steam inflow resistant chamber in the radial direction. Introduced from the turbine rotor, the cooling steam flowing into the steam inflow resistant chamber is received at the outer circumferential portion of the turbine rotor facing the auxiliary stationary vanes, and power is generated, and the flow path of the steam is changed from the radial flow direction to the axial flow direction. This is achieved by arranging auxiliary rotor blades that change the temperature and cooling the outer periphery of the steam inlet chamber portion of the turbine rotor by the worked steam that has passed through the auxiliary rotor blades.

Embodiments of the present invention will be described below based on the drawings. Fourth
The figures show an embodiment of the present invention; FIG. 5 is a longitudinal cross-sectional view of the main part of the high-temperature steam inlet chamber of a double-flow steam turbine; FIG. 5 is a detailed view of section P shown in FIG. 4; and FIG. In the figure, (α) is the B-E cross section in Figure 4, and (6) is (
This figure shows the details of part 9 shown in α). In the figure, the same components as those shown in FIG. 1 are given the same reference numerals and their explanations will be omitted. Reference numeral 43 denotes an annular partition wall member, which is provided to cover the outer periphery of the turbine rotor 40 between the stator blades 11' of the first stage, sandwiching the inlet chamber 14, and 43 is an annular partition member. ), is divided into two parts as shown in G9, and has protrusions 4 as shown in FIG.
3a, and is supported by the shroud 19 of the first stage static R11. The steam inflow chamber 14 is formed by this partition wall member 43.
It is divided into a main steam inflow chamber 14α on the outer diameter side and a steam-resistant inflow chamber 14/l on the inner diameter side. In addition, the main steam inflow chamber 14
As shown in FIG.
An opening 45 is provided between the auxiliary stationary vanes 44, through which the two main steam inflow chambers 14α and the steam-resistant inflow chamber 14b communicate with each other. The outer periphery of the turbine rotor 40 facing this opening 45 is shown in FIG.
As shown in the figure, a plurality of auxiliary movement R46 are arranged.

4Qα is a reinforcing rib of the auxiliary rotor blade 46. As shown in FIG. 4, the high temperature steam flows from the inlet 15 in the direction of arrow 47 and is guided to the main steam inflow chamber 14α. Main steam inflow chamber 14α
Most of the steam guided by the steam flows in the direction of arrow 16, passing through the first stage stationary blades 11 and the first stage rotor blades 11 in order to generate torque that rotates the turbine rotor 40. In addition, a part of the steam passes through the space 45 between the auxiliary stationary vanes 44 provided in the middle part of the partition wall member 43 in the radial direction 48 as shown in (A) in FIG. The steam is injected to the auxiliary rotor blades 46 to generate torque that rotates the turbine rotor 40.The steam that has completed its work in the auxiliary rotor blades 46 flows to the left and right of the steam-resistant inlet chamber 14b in the axial direction as seen by arrow 18, and is transferred to the first stage. The steam from the main steam inflow chamber 14α joins with the steam from the main steam inlet chamber 14α on the exit side of the stator vane 11″. In this way, a part of the high temperature steam at the inlet of the steam turbine is transferred to the steam inflow chamber 14 through the auxiliary stationary vanes 44.
/I, and the temperature of the introduced steam is lowered by performing work on the auxiliary rotor blades 46, and this introduced steam can maintain the surface temperature of the turbine rotor 40 at a lower temperature than the high temperature at the turbine inlet.

FIG. 7 shows another embodiment of the present invention, in which (α)
(b) shows a longitudinal cross section of the main part of the high temperature steam inlet chamber of the steam turbine of Gupuru 70-, and (b) shows the a-O cross section of (cL). In the figures, the same components as those shown in FIG. 4 are designated by the same reference numerals, and their explanations will be omitted. A labyrinth packing 71 is provided between the first-stage stationary blade 11 and the turbine rotor 40, and the steam that has finished its work at the auxiliary rotor blade 45 flows through the steam-resistant inflow chamber 14'A in the axial flow direction,
The liquid flows out to the second stage stator vane 12' side through a radial hole 72 provided in the stator vane 11 of the stage and a communication hole 73 provided in the stator vane holder 10'.

By causing the steam to flow out to the lower pressure side after the first stage rotor blade 11 in this manner, the pressure of the steam flowing through the steam-resistant inflow chamber 14b is lowered, and the temperature is lowered. Therefore, the surface temperature of the turbine rotor 40 in the side cover air inflow chamber 146 portion can be maintained at a lower temperature.

FIG. 8 shows still another embodiment of the present invention, and is a longitudinal cross-sectional view of a main part of a high-temperature steam inlet chamber of a single-flow steam turbine. In the figure, 87 is a stator blade holder, 80 is a turbine rotor, and the stator blade holder 87 is sandwiched between the high temperature steam inflow chamber 85.
An annular partition member 83 is provided between the first stator vane row 81 and the steam inflow chamber 85, and the steam inflow chamber 85 is divided into a main steam inflow chamber 85α and a sub-steam inflow chamber 85b. The partition wall member 83 is provided with auxiliary stator vanes 84 similar to those shown in FIG.
Auxiliary rotor blades 86 are provided on the turbine rotor 80 facing the turbine rotor 80 . The main steam flows in the direction of arrow 88α and is guided to the first stage stator blade row 81 and subsequent blade rows. The steam that has flowed into the subgroup air inflow chamber 85b via the auxiliary stationary vane 84 does work in the auxiliary station R86, and because one outlet end is closed by the labyrinth packing 89, the steam flows in the direction of the arrow 88b. It merges with the main steam at the outlet side of the first stage stationary blade 81, and cools the outer periphery of the turbine rotor 8o in the steam inlet chamber 85 portion.

As described above, the present invention guides a part of the working fluid to the auxiliary rotor blades of the turbine rotor via the auxiliary stator vanes, and distributes the worked, low-humidity working fluid that has passed through the auxiliary rotor blades to the subgroup air inflow chamber. As a result, it is possible to provide a steam turbine rotor cooling device that has a simple structure and has a large cooling effect that does not affect the thermal cycle of the working fluid.

[Brief explanation of the drawing]

Fig. 1 shows a conventional embodiment, which is a vertical sectional view of the main part of the high-temperature steam inlet chamber of a double-flow steam turbine, and Fig. 2 shows another conventional embodiment, which shows the high-temperature steam inflow of a single-flow steam turbine. A vertical cross-sectional view of the main part of the chamber, FIG. 3 shows still another conventional embodiment, in which (α) is a vertical cross-section of the main part of the high-temperature steam inlet chamber of a double-flow steam turbine, and (h) is
), FIG. 4 shows an embodiment of the present invention, and FIG. 5 is a longitudinal sectional view of the main part of the high temperature steam inlet chamber of a double flow steam turbine, and FIG. 5 shows the P section shown in FIG. 4. FIG. 6 further shows the main part of FIG. 4, and (α) shows the BB cross section of FIG. Figure 7 shows another embodiment of the present invention, in which (α) shows a longitudinal section of the main part of the high-temperature steam inlet chamber of a double-flow steam turbine, and (b) shows the a-C cross section of (α). FIG. 8 shows still another embodiment of the present invention, and is a longitudinal cross-sectional view of a main part of a high-temperature steam inlet chamber of a single-flow steam turbine. 1self 81: Stationary blade, 14.85: Steam inflow chamber, 14α. 85σ: Main steam inflow chamber, 14b, 85b: Subgroup air inflow chamber, 40.80: Turbine rotor, 43.83
: Bulkhead assembly, 44.84 : Auxiliary stator vane, 46.86
: Auxiliary casing, 71.89 : Labyrinth packing, 72
: hole, 73: communicating hole. j Su 1 day 72 圀(b74 Figure 11' γ mu 口(Su7'7 Figure 78 硼

Claims (1)

[Claims] 1) An annular steam inflow chamber is divided into a main steam inflow chamber on the outer diameter side and a side cover air inflow chamber on the inner diameter side by an annular partition member supported on the fixed part side of the inflow chamber. , radial-type auxiliary stator vanes are disposed within the partition wall member, and turbine rotor cooling steam is introduced from the main steam inflow chamber to the side cover air inflow chamber from the radial direction through the auxiliary stator vanes, and the turbine rotor is cooled. An auxiliary rotor blade is disposed on an outer peripheral portion facing the auxiliary stator vane, which generates power by receiving the cooling steam flowing into the side cover air inflow chamber and changes the flow path of the steam from an axial flow direction to an axial flow direction. A cooling device for a steam turbine rotor, characterized in that the outer periphery of a steam inflow chamber portion of the turbine rotor is cooled by the worked steam that has passed through the auxiliary rotor blades. 2. In the cooling device according to claim 1, the steam turbine is an axial flow double-acting turbine, the partition member is supported by stator vanes at both ends, and the auxiliary stator vane is located at the axial center of the partition member. A cooling device for a steam turbine rotor, characterized in that the auxiliary rotor blades are arranged in the side cover air inflow chamber and divide and convert the flow path of cooling steam flowing into the side cover air inflow chamber from the radial flow direction to the left and right axial flow directions. . 3), ;l'l+yo. □Yes, 18. . □Eng. 5
: The end of the partition wall member is supported by the stator blade, and a labyrinth packing is provided between the end of the partition wall member and the outer periphery of the turbine rotor, and cooling steam from the auxiliary rotor blade is perforated into the stator blade. A cooling device for a steam turbine rotor, characterized in that the cooling device is led to a low pressure part of a turbine through a radial hole provided and a communication hole drilled in a stator vane holder that supports the stator blade.