JP5703082B2 - Dehumidifier for steam turbine - Google Patents

Description

  Embodiments described herein relate generally to a turbine moisture removal apparatus for a steam turbine.

  In the low-pressure stage of a steam turbine used in a power plant, the temperature and pressure of the steam, which is a working fluid, are lowered during the process of expanding the steam, so that a part of the steam is condensed in the flow path to become moisture. FIG. 10 shows a final low-pressure turbine composed of a pair of a turbine nozzle 1 supported between the diaphragm inner ring 2 and the diaphragm outer ring 3 and blades 4 arranged downstream of the turbine nozzle 1 and implanted in the turbine rotor 5. The trajectories of vapor and droplets are schematically shown in the region where the blades 4A of the previous paragraph having the same configuration as the paragraph are added.

  In FIG. 10, the working fluid vapor follows a trajectory as indicated by the flow line 36, whereas the moisture generated up to the previous paragraph is in the form of droplets, and the blade trailing edge of the blade 4 </ b> A. It is scattered from 37 to the diaphragm outer ring 3 side of the turbine nozzle 1 by a centrifugal force like a streamline 38.

  When these water droplets adhere to the periphery of the front edge 39 of the turbine nozzle 1, they flow on the surface toward the rear edge while forming a water film 40 on the surface, and when they reach the rear edge 41 of the turbine nozzle 1, they become water droplets again. Scatter. At this time, the water droplet cannot catch the flow of the steam due to inertia and collides with the vicinity of the front edge 42 of the blade 4 to cause erosion. Further, the collision of the water droplets causes a braking action against the rotation of the blades 4 and also consumes steam energy for accelerating the water droplets.

  Thus, various structures have been proposed to remove moisture that adversely affects turbine efficiency and reliability. For example, in order to separate and remove moisture adhering to the turbine nozzle surface, the inside of the turbine nozzle 1 is made hollow, a slit is provided on the surface, and moisture is collected and removed inside the turbine nozzle. There are those that flow high-temperature steam to prevent the generation of droplets, and those that provide a porous material with excellent water absorption and thermal conductivity on the surface of the turbine nozzle and that are heated by an electrical heat source.

Japanese Patent Laid-Open No. 11-22410 Japanese Patent Laid-Open No. 10-103008 JP 2010-116922 A

  However, among the moisture separation methods described above, in the method of discharging moisture from the turbine nozzle surface through the slit, the water film 40 on the surface of the turbine nozzle 1 moves while being dragged by the flow of steam as shown in FIG. In the process, it may be divided into several trickles 43 and water droplets 44 and head to the turbine nozzle trailing edge 41. Therefore, if a slit 45 is provided in the middle, not only moisture but also steam is entrained together. The steam flow may be reduced and the performance of the turbine may be reduced. For the steam turbine, it is desirable that only the water film 40 can be selectively removed.

  Moreover, when a porous material is used for the turbine nozzle surface, the turbine nozzle surface roughness increases and the friction loss on the surface increases. As a result, the aerodynamic performance of the turbine nozzle is lowered, and there is a disadvantage that the turbine efficiency is lowered.

  Therefore, the present invention evaporates a part or all of the liquid film formed on the turbine nozzle surface to suppress collision of relatively large water droplets on the suction surface side of the blade, thereby reducing braking loss and erosion. It is an object of the present invention to provide a moisture removing device for a steam turbine that can be performed.

  The steam turbine moisture removal device according to the present embodiment includes a diaphragm inner ring disposed on the outer periphery of the turbine rotor via a gap, a diaphragm outer ring disposed radially outward of the diaphragm inner ring, the diaphragm inner ring, and the diaphragm inner ring. A plurality of turbine nozzles supported by the outer ring of the diaphragm and arranged at a predetermined interval in the circumferential direction, and adjacent to the rear edge of the turbine nozzle and arranged at a predetermined interval in the circumferential direction. In the steam turbine moisture removing apparatus having one or more turbine stages comprising a plurality of blades attached to the turbine rotor as described above, a trailing edge from an intermediate portion on the ventral surface of the turbine nozzle An electric heating part having a smooth surface that is flush with the ventral side surface of the surrounding turbine nozzle is provided in a region extending over .

It is a figure which shows the moisture removal apparatus of the steam turbine which concerns on the 1st Embodiment of this invention, (a) is the figure which looked at the steam turbine stage from the meridian surface, (b) is AA 'cross section of a stationary blade Figure. The figure which shows the moisture removal apparatus of the steam turbine which concerns on the 2nd Embodiment of this invention. It is a figure which shows the moisture removal apparatus of the steam turbine which concerns on the 3rd Embodiment of this invention, (a) is the figure which looked at the steam turbine stage from the meridian surface, (b) is AA 'cross section of a stationary blade Figure. It is a figure which shows the moisture removal apparatus of the steam turbine which concerns on the 4th Embodiment of this invention, (a) is the figure which looked at the steam turbine stage from the meridian surface, (b) is AA 'cross section of a stationary blade Figure. It is a figure which shows the moisture removal apparatus of the steam turbine which concerns on the 5th Embodiment of this invention, (a) is the figure which looked at the steam turbine stage from the meridian surface, (b) is AA 'cross section of a stationary blade Figure. The figure which shows the moisture removal apparatus of the steam turbine which concerns on the 6th Embodiment of this invention. The figure which shows the moisture removal apparatus of the steam turbine which concerns on the 7th Embodiment of this invention. The figure which looked at the steam and moisture flow of the steam turbine stage of a prior art from the meridian plane. The figure which looked at the steam turbine nozzle which provided the slit of a prior art, and the flow of moisture from the meridian surface.

  Hereinafter, a steam turbine moisture removing apparatus according to an embodiment of the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected to the same or similar components and site | parts throughout each figure, and the overlapping description is abbreviate | omitted suitably.

[First Embodiment]
Hereinafter, a first embodiment of a steam turbine moisture removing device according to the present invention will be described with reference to FIGS.

(Constitution)
FIG. 1 is a diagram showing a configuration of a turbine moisture removing apparatus according to a first embodiment, FIG. 1 (a) is a diagram showing an arbitrary turbine stage, and FIG. 1 (b) is a diagram of FIG. 1 (a). It is AA 'sectional drawing of a turbine nozzle.

  The steam turbine is disposed between the diaphragm inner ring 2 and the diaphragm outer ring 3 at a predetermined interval in the circumferential direction, and is disposed on the downstream side (steam) of the turbine nozzle 1 and the outer periphery of the turbine rotor 5. A plurality of turbine stages each composed of a blade 4 attached to the part by planting or the like are installed in the longitudinal direction of the rotor.

  In the present embodiment, as shown in FIG. 1 (b), with respect to a portion extending from the intermediate portion where the liquid film 7 in the direction 8 of the steam flow on the ventral surface 1a of the turbine nozzle 1 is formed to the trailing edge of the turbine nozzle. An electric heating section 6 is provided as a moisture removing means. Here, the intermediate portion of the ventral surface 1a does not mean the central portion between the front edge and the rear edge of the turbine nozzle 1, but the region near the front edge and the region near the rear edge. It means the area between.

  The step portion 1b is formed so that the portion on the ventral surface 1a where the electric heating portion 6 is provided is slightly depressed from the surrounding portion. And the electrothermal part 6 is affixed on this level | step-difference part 1b with the adhesive agent rich in heat resistance.

  The surface of the electric heating part 6 is formed on the same surface as the surrounding ventral surface 1a to which the electric heating part 6 is not attached as shown in FIG. 1B, and the surface of the electric heating part 6 itself is also smoothly processed. ing. Therefore, the stepped portion does not occur on the abdominal surface 1a of the turbine nozzle 1 due to the attachment of the electric heating portion 6, and the surface of the electric heating portion 6 itself is smoothly processed. The side surface 1a does not increase the friction loss as compared with the prior art.

  The electric heating section 6 sets the amount of electric power via a diaphragm outer ring 3 and a thermally and electrically insulated cable (hereinafter simply referred to as an electric cable) 10 provided through a turbine casing (not shown) that supports the diaphragm outer ring 3. It is designed to be connected to the device 11. Although the internal configuration of the power amount setting device 11 is not particularly illustrated, it includes at least a power source and a power setting unit, and the power setting unit generates the liquid film 7 predicted in each turbine stage when the turbine stage is designed. The electric power required for the evaporation of the liquid film 7 is set so as to supply the electric heating unit 6 according to the amount.

(Function)
When the steam flow 8 as the working fluid flows into the turbine nozzle 1, the steam condenses in the vicinity of the blade leading edge due to the decrease in the steam temperature accompanying the expansion of the saturated steam, and the droplet 9 is generated. The droplet 9 flows on the ventral surface 1a of the turbine nozzle 1 toward the trailing edge of the turbine nozzle 1 while forming the liquid film 7, and then scatters and rotates again as a droplet reaching the trailing edge of the turbine nozzle. Collide with the blade 4
At this time, the scattered liquid droplets are relatively large and collide with the back side front edge of the blade 4, so that a braking force is applied to the rotation of the blade and a braking loss is generated.

  Therefore, in the first embodiment, an electric heating section 6 is provided as a moisture removing means from a portion where the liquid film 7 of the ventral surface 1a of the turbine nozzle 1 is formed to a portion including the trailing edge of the turbine nozzle. By supplying preset electric power from the electric energy setting device 11 to the electric heating unit 6 via the electric cable 10, the liquid film 7 flowing on the ventral surface 1 a of the turbine nozzle 1 toward the rear edge of the turbine nozzle All or most of the liquid was evaporated by heating so that the droplets 9 were not generated again at the trailing edge of the turbine nozzle.

  As a result, since the droplet 9 does not scatter from the trailing edge of the turbine nozzle 1 and does not collide with the rotating blade 4 as in the prior art, a braking force is applied to the rotation of the blade to generate a braking loss. There is no.

(effect)
As described above, according to the steam turbine moisture removing device of the present embodiment, the turbine nozzle trailing edge from the intermediate portion where the liquid film 7 in the steam flow direction of the ventral surface 1a of the turbine nozzle 1 is formed. Since the electric heating part 6 is provided as a moisture removing means for the part extending over and the liquid film 7 flowing on the ventral surface 1a toward the rear edge of the turbine nozzle is heated and evaporated by the electric heating part 6, the operation is performed. Wetness in steam is reduced, the amount of relatively large droplets that are the main cause of moisture loss can be eliminated or suppressed, turbine efficiency can be improved, and blade erosion can be suppressed It becomes.

[Second Embodiment]
Hereinafter, a second embodiment of the steam turbine moisture removing apparatus according to the present invention will be described with reference to FIG.

(Constitution)
In FIG. 2, the turbine moisture removal apparatus showing the second embodiment according to the present invention is characterized in that a liquid film detection sensor is added to the turbine moisture removal apparatus of the first embodiment (FIG. 1). Is.

  That is, with respect to a portion extending from the intermediate portion where the liquid film 7 in the direction 8 of the steam flow on the ventral surface 1a of the turbine nozzle 1 fixed between the diaphragm inner ring 2 and the diaphragm outer ring 3 is formed to the turbine nozzle trailing edge. In the turbine moisture removing apparatus configured by forming a stepped portion 1b that is slightly depressed from the surrounding portion and attaching the electric heating unit 6 to the stepped portion 1b, in the vicinity of the electric heating unit 6, for example, the surface of the electric heating unit 6 A concave portion is provided on the diaphragm outer ring 3 side, and the liquid film detection sensor 14 is accommodated therein.

Then, the electric heating unit 6 is connected to the control device 11 </ b> A by the electric cable 12 and the liquid film detection sensor 14 is connected by the sensor signal line 30. Needless to say, the sensor signal line 30 is heat-resistant coated like the electric cable 12.
The surfaces of the electric heating unit 6 and the liquid film detection sensor 14 are continuous with the surrounding portion of the ventral surface 1a, and the surfaces are processed smoothly so that the friction loss of the blades does not increase.

(Function)
When the control device 11A receives the liquid film detection signal from the liquid film detection sensor 14, the control device 11A evaporates the liquid film 7 by supplying power to the electric heating unit 6 through the electric cable 12 to generate heat, and conversely. When the liquid film detection signal from the liquid film detection sensor 14 is not input, the power supply to the electric heating unit 6 is cut off.

(effect)
As described above, according to the moisture removing device for a steam turbine of the present embodiment, the liquid film detection sensor 14 is provided in addition to the electric heating unit 6, and when the liquid film detection sensor 14 detects the liquid film, or Since the electric power supplied to the electric heating unit 6 is controlled to be turned on or off according to the situation when not detected, the liquid film 7 is evaporated while the consumption of electric power used for moisture removal is minimized. Accordingly, it is possible to reduce the wet loss of the turbine and provide an efficient turbine.

[Third Embodiment]
Hereinafter, a third embodiment of the steam turbine moisture removing device according to the present invention will be described with reference to FIGS. 3 (a) and 3 (b).

(Constitution)
3 (a) and 3 (b), the turbine moisture removing apparatus showing the third embodiment according to the present invention is characterized in that a piezoelectric element 13 is added to the turbine moisture removing apparatus of the first embodiment. It is what.

  That is, in addition to attaching the above-described electric heating portion 6 to the stepped portion 1b formed in the region extending from the intermediate portion where the liquid film 7 of the ventral surface 1a of the turbine nozzle 1 is formed to the turbine nozzle trailing edge, piezoelectricity is applied. The element 13 is affixed, and a conductive wire 12 that connects the piezoelectric element 13 and the electric heating unit 6 is affixed. As for the positional relationship of these components, the electric heating portion 6 is disposed in the vicinity of the rear edge of the ventral surface 1a of the turbine nozzle 1, and the piezoelectric element 13 is disposed on the front edge side thereof.

  In the case of the present embodiment, since the electric power supplied to the electrothermal unit 6 is covered by the electromotive force generated in the piezoelectric element 13, the electric cable 10 and the power setting device 11 of the first embodiment described above can be omitted. .

(Function)
In the turbine nozzle 1 in the low pressure stage, the wetness increases toward the downstream, and the droplet 9 flowing through the passage portion forms a liquid film 7 on the ventral side of the turbine nozzle 1. The nozzle 1 is also subjected to pressure by the steam flow 8 in the passage. An electromotive force is generated in the piezoelectric element 13 attached to the surface of the nozzle 1 by the pressure of the steam flow 8 received by the nozzle 1. The electromotive force generated in the piezoelectric element 13 is supplied to the electric heating unit 6 through the conducting wire 12 to generate Joule heat in the electric heating unit 6 to evaporate the liquid film 7. In addition, since the nozzle 1 vibrates minutely by the steam flow 8 in the passage portion, the electromotive force generated by the steam pressure and the electromotive force generated by the vibration energy are added to the piezoelectric element 13 attached to the ventral surface 1a of the nozzle 1. Electromotive force is generated.

(effect)
As described above, according to the moisture removing device for a steam turbine of the present embodiment, the electric heating unit 6 is caused to generate heat by the electric power generated by the piezoelectric element 13 attached to the ventral surface 1a of the turbine nozzle 1. Therefore, in addition to the effect which 1st Embodiment show | plays, simplification of the structure by omission of the electric energy setting apparatus 11 and the electric cable 10 can be achieved.

[Fourth Embodiment]
Hereinafter, a fourth embodiment of the steam turbine moisture removing device according to the present invention will be described with reference to FIGS. 4 (a) and 4 (b).

(Constitution)
4 (a) and 4 (b), a turbine moisture removing device showing a fourth embodiment according to the present invention is configured such that a turbine nozzle is formed from an intermediate portion where a liquid film 7 on the ventral surface 1a of the turbine nozzle 1 is formed. In addition to attaching the electric heating part 6 and the piezoelectric element 13 to the step part 1b formed at the site extending over the rear edge, a liquid film detection sensor 14 for detecting the liquid film on the ventral surface 1a of the turbine nozzle 1 is attached. It is comprised as follows.

The mounting position of the liquid film detection sensor 14 is embedded in a recess formed in the electrothermal section 6 as in the second embodiment (FIG. 2) described above, for example.
Needless to say, the surface of the electric heating unit 6, the piezoelectric element 13, and the liquid film detection sensor 14 is configured to be continuous with the portion around the ventral surface 1a.

  The electric heating unit 6 is connected to a power supply device (not shown) via the electric cable 10 as in the first embodiment, while the liquid film detection sensor 14 is supplied with electric power necessary for operation from the piezoelectric element 13, The film detection signal is sent to a power supply device (not shown) that supplies electricity to the electric heating unit 6.

(Function)
In the turbine nozzle 1 in the low pressure stage, the wetness increases toward the downstream, and the droplet 9 flowing through the passage portion forms a liquid film 7 on the ventral side of the turbine nozzle 1. Further, the nozzle 1 vibrates slightly by the steam flow 8 in the passage portion. As in the second embodiment, the piezoelectric element 13 attached to the surface of the nozzle 1 generates an electromotive force by vibration energy, and electric power is supplied to the liquid film detection sensor 14 attached to the surface of the nozzle 1 by this electromotive force. . The electric heating unit 6 is supplied with electric power having a magnitude corresponding to the signal of the liquid film detection sensor 14 from a power supply device (not shown), and generates heat to evaporate the liquid film 7.

(effect)
As described above, according to the moisture removing device for a steam turbine of the present embodiment, the electrothermal unit 6, the piezoelectric element 13, and the liquid film detection sensor 14 are provided on the ventral surface 1 a of the turbine nozzle 1, and the liquid film detection sensor is provided. Since the electric heating unit 6 is configured to generate heat in response to the 14 output signals, the liquid film 7 can be appropriately evaporated as compared with the first and second embodiments. In addition, since the power necessary for the operation of the liquid film detection sensor 14 is covered by the power generated by the piezoelectric element 13, the connection configuration with an external circuit is simplified. Others are the same as the effect which 1st Embodiment thru | or 3rd Embodiment show | plays.

[Fifth Embodiment]
Hereinafter, a fifth embodiment of the steam turbine moisture removing apparatus according to the present invention will be described with reference to FIGS.

(Constitution)
5 (a) and 5 (b), the turbine moisture removing apparatus according to the fifth embodiment of the present invention is located at a position facing the ventral surface 1a of the turbine nozzle 1 and the steam flow 8 of the diaphragm outer ring 3. The piezoelectric element 13 is attached, and a space is provided in a part of the diaphragm outer ring 3. The storage battery 15 is accommodated in the space, and the storage battery 15, the electric heating unit 6, the piezoelectric element 13, and the liquid film detection sensor 14 are connected to the lead 12. Is electrically connected.

(Function)
In the turbine nozzle 1 in the low pressure stage, the wetness increases toward the downstream, and the droplet 9 flowing through the passage portion forms a liquid film 7 on the ventral side of the turbine nozzle 1. Further, the nozzle 1 vibrates slightly by the steam flow 8 in the passage portion. The piezoelectric elements 13 attached to the surface of the nozzle 1 and the surface of the diaphragm outer ring 3 generate an electromotive force based on pressure and vibration energy generated by the steam flow 8 and store the electromotive force in the storage battery 15. The liquid film detection sensor 14 and the electric heating unit 6 are supplied with electric power stored in the storage battery 15.

(effect)
As described above, according to the moisture removing device for a steam turbine of the present embodiment, the liquid film detection sensor 14 and the electric heating unit 6 are supplied with the electric power stored in the storage battery 15. There is no need to supply from the turbine casing as in the embodiment, and the configuration is simplified accordingly. Others are the same as the effect which 1st Embodiment thru | or 3rd Embodiment show | plays.

[Sixth Embodiment]
Hereinafter, a sixth embodiment of the steam turbine moisture removing device according to the present invention will be described with reference to FIG.

(Constitution)
FIG. 6 shows a turbine moisture removing apparatus according to a sixth embodiment of the present invention, and particularly shows a downstream turbine stage having a long blade length.
The turbine moisture removal apparatus of the present embodiment is characterized in that the electric heating unit 6 is biased to the diaphragm outer ring 3 side (or casing side) corresponding to the trajectory of droplets.

(Function)
As shown in the figure, the steam flow 8 flows from the first turbine stage (nozzle 1 ₁ , blade 4 ₁ ) to the second turbine stage (nozzle 1 ₂ , blade 4 ₂ ) and further to the third turbine stage (nozzle 1 ₃ , blade 4 _3). ), The length of the turbine nozzle 1 and the blades 4 increases, so that the steam passing through each turbine stage also spreads to the diaphragm outer ring 3 side (or casing side). Moreover, since the steam flow 8 performs the work of rotating the blades 4, it gradually loses energy and condenses into droplets.

For example, the droplets scattered from the blade 4 of the _second turbine stage is a centrifugal force of the blades 4 _2, toward the diaphragm outer ring 3 side as indicated by broken line arrows 28 (or turbine casing), downstream of the third turbine position at which the liquid film collides with the nozzle 1 ₃ paragraph is often the position of over the diaphragm outer ring 3 side from the substantially central portion of the third blade height 29 direction of the nozzle 1 ₃ turbine stage (or casing).

  For this reason, in the present embodiment, the electric heating section 6 is not arranged from the diaphragm inner ring 2 to the diaphragm outer ring 3, but is arranged so as to be biased from the substantially central portion in the blade height 29 direction toward the diaphragm outer ring 3 side (or casing side). It is what you do.

(effect)
By configuring as described above, it is possible to intensively heat the liquid film 7 that exists in a large amount from the substantially central portion of the blade height 29 to the diaphragm outer ring 3 side (or the casing side). Since the area can be reduced and only necessary portions can be heated, the amount of heat used for liquid film evaporation, that is, electric power can be reduced. Furthermore, since the electric heating part 6 is not provided in a wide range, the cost can be reduced.
Others are the same as the operational effects of the first embodiment.

[Seventh Embodiment]
A seventh embodiment of the steam turbine moisture removing device according to the present invention will be described below with reference to FIG.

(Constitution)
In FIG. 7, the turbine moisture removing device according to the seventh embodiment of the present invention connects the electric heating unit 6 and the liquid film detection sensor 14 to the diaphragm outer ring 3 side (or casing side) corresponding to the trajectory of the droplets. It is characterized by being arranged in a biased manner.

  That is, the electric heating parts 6 are arranged in two rows (three in total) in the height direction on the diaphragm outer ring 3 side in the vicinity of the rear end edge of the ventral surface 1a of the turbine nozzle 1 and surround each electric heating part 6. The liquid film detection sensor 14 is attached to the. And the point which connects the electrothermal part 6 to the control apparatus 11A with the electric cable 12, and the liquid film detection sensor 14 with the sensor signal line 30 is the same as 2nd Embodiment (FIG. 2). The numbers of the heating device 33 and the liquid film detection sensors 14 are not limited to the illustrated example, and may be plural or single.

(Function)
Information obtained from the liquid film detection sensor 14 is sent to the control device 11A via the sensor signal line 30. The control device 11A estimates based on the information obtained from the liquid film detection sensor 14 to estimate the distribution of the liquid film, and determines which part of the heating device to send electricity to based on the estimation result. And based on the determination result, it supplies electric power to the corresponding heating device 6 through the electric cable 10 to generate heat.

  As described above, according to the moisture removing device for a steam turbine of the present embodiment, the distribution of the liquid film is estimated based on the information obtained from the liquid film detection sensor 14, and the place where the liquid film exists is selected. Then, the liquid film can be evaporated by heating. As a result, since the place where the liquid film does not exist is not heated, the liquid film can be efficiently evaporated with the minimum necessary power. Others are the same as the effect which 1st Embodiment thru | or 2nd Embodiment show | plays.

  The embodiment described above is presented as an example, and is not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 1 ... Turbine nozzle, 2 ... Diaphragm inner ring, 3 ... Diaphragm outer ring, 4 ... Blade | wing, 5 ... Turbine rotor, 6 ... Electric heating part, 7 ... Liquid film, 8 ... Steam flow, 9 ... Droplet, 10 ... Electric cable, DESCRIPTION OF SYMBOLS 11 ... Electric energy setting apparatus, 12 ... Conductor, 13 ... Piezoelectric element, 14 ... Liquid film detection sensor, 15 ... Storage battery, 28 ... Droplet flow, 29 ... Blade height, 30 ... Signal wire, 36 ... Steam flow Line 37: Final front blade trailing edge 38: Moisture stream line 39 Turbine nozzle leading edge 40 Water film 41 Turbine nozzle trailing edge 42 Final blade front edge 43 ... trickle, 44 ... water drop, 45 ... slit.

Claims (8)

A diaphragm inner ring disposed on the outer periphery of the turbine rotor via a gap, a diaphragm outer ring disposed radially outward of the diaphragm inner ring, supported by the diaphragm inner ring and the diaphragm outer ring, and provided with a predetermined interval in the circumferential direction. A plurality of turbine nozzles arranged at intervals, and a plurality of blades attached to the turbine rotor so as to be arranged at a predetermined interval in the circumferential direction adjacent to the rear edge of the turbine nozzle. In the steam turbine moisture removal apparatus having one or more turbine stages,
A steam turbine characterized in that an electric heating part having a smooth surface in the same plane as a ventral side surface of a surrounding turbine nozzle is provided in a region extending from an intermediate portion to a rear edge on the ventral surface of the turbine nozzle. Turbine moisture removal device.   The turbine moisture of a steam turbine according to claim 1, wherein a liquid film detection sensor is provided in the vicinity of the electric heating section, and electric power supplied to the electric heating section is controlled based on a detection signal of the liquid film detection sensor. Removal device.   The turbine moisture removal device for a steam turbine according to claim 1 or 2, wherein a piezoelectric element is attached in the vicinity of the electric heating section. The turbine moisture removal device for a steam turbine according to claim 2 , wherein a piezoelectric element is attached in the vicinity of the electric heating section, and electric power generated by the piezoelectric element is supplied to the liquid film detection sensor.   The turbine moisture removal apparatus for a steam turbine according to claim 3 or 4, wherein the electric power generated by the piezoelectric element is supplied to the electric heating section. The storage battery is housed in a space provided in the outer ring of the diaphragm, and electricity generated by the piezoelectric element is stored in the storage battery, and the electric heating unit and the liquid film detection sensor are fed by the storage battery. 4. A turbine moisture removing device for a steam turbine according to claim 4 .   The turbine moisture removal of a steam turbine according to any one of claims 1 to 6, wherein a range in which the surface of the turbine nozzle is heated is on the diaphragm outer ring side with respect to a substantially center of blade height. apparatus. A plurality of the liquid film detection sensor and the electric heating unit are provided, and a control device that supplies power by selecting an electric heating unit to be heated from the plurality of electric heating units based on a detection signal of the liquid film detection sensor. The turbine moisture removal device for a steam turbine according to claim 2.

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