JPH1090136A - Large-size water drop-collecting probe for steam flow in turbine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To properly collect liquid drops by forming a shutter cylinder end part selectively aligning with an axial slit fitted in a freely detachable and rotatable fashion in an outer cylinder, and a liquid drop circulation space from a leading end part of the axial slit to a leading end part of a moisture-absorbing mat member in a positioning metal fitting. SOLUTION: An outer cylinder 51 of a water drop probe 50 is formed by sequentially coupling a guide tube 53, a slit tube 55 and a leading guide tube 57 through meshing or the like manner. The slit tube 55 has a slit hole 55a extending in an axial direction, and the leading guide tube 57 has a slit tube hole 57a expanding up to a center position. A positioning metal fitting 59 is fixed at an internal leading end part of the leading guide tube 57. A shutter cylinder 61 is inserted in the outer cylinder 51 in a freely detachable state, having a slit hole 61a selectively aligning with the slit hole 55a. A mat-mounting stage 71 is fixed inside a slot part 65a at a lower part of a supporting rod 65. A moisture-absorbing mat material 75 facing from inside is secured to the mounting stage 71. Moreover, an axial space is provided at a central part of a base end part 65b of the supporting rod 65.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a probe used for measuring a liquid phase in a gas-liquid two-phase fluid such as a wet steam flow, and more particularly to a method for collecting water droplets contained in a steam flow in a low-pressure turbine. The present invention relates to a coarse water drop sampling probe used in the present invention.

[0002]

2. Description of the Related Art In a power plant in which a generator is driven by using a steam turbine, near-saturated steam is introduced into a low-pressure turbine. And may cause erosion of the moving blade, or may cause deterioration of blade performance. Therefore, in order to improve the performance of the low-pressure turbine, it is important to measure and grasp the behavior or track pattern of the coarse water droplets in the steam flow. The coarse water droplets are collected in the manner shown in FIG. In FIG. 3, the turbine rotor 1
The moving blades 3 and 5 implanted in are driven by the steam guided by the stationary blades 7 and 9. That is, the steam flows as shown by the white arrow. Then, the trace pattern of the coarse water droplet of the steam flow passing through the final stage stationary blade is measured by the probe 20 inserted from the outside of the outer casing 11. 4 and 5 show the mounting state of the probe 20 in a little more detail. The probe 20 is inserted through the mounting pipe 13 of the outer casing 11, and FIG.
The drive unit 15 opens and closes the water drop inlet of the probe 20. The probe 20 can move the water drop inlet from the base side of the wing to the tip side of the wing and rotate around the axis, fix the inlet at a required position and in a desired direction, and collect water drops in the steam flow. I do.

FIGS. 6 to 8 show the structure of a conventional probe 20. FIG. Referring to these figures, probe 2
The outer cylinder 21 having an elongated circular cross section of 0 has a slit hole 21a as a water droplet intake port, and a mat member 23 for water droplet adsorption is fixed to the mounting table 25 from the inside thereof. The mount 25 is further fixed to a support rod 27 of an assembled structure, and a mat member 23, a shutter cylinder 29 surrounding the mount 25 and the support rod 27 are rotatable at both ends of the support rod 27 via bearings 31 and 33. I support it. The shutter cylinder 29 can be inserted into and removed from the outer cylinder 21 together with the internal structural members. The shutter cylinder 29 has a slit hole 29a that is selectively aligned with the slit hole 21a of the outer cylinder 21. The plunger 35 inserted into the central shaft hole at the upper part of the support rod 27
The air hose 39 is fixed to the shutter cylinder 29 via a pin 37, and an air hole of the air hose 39 is opened toward an outer end surface thereof.
When high-pressure air is discharged from the air hose 37, the plunger 35 is opposed to the axial spring 41 and the rotational spring 43.
Move. Shutter cylinder 29 connected to plunger 35
Rotates while being displaced in the axial direction with respect to the support rod 27, the slit holes 21a and 29a are aligned, and the shutter is opened. The state shown in the figure shows this state. Normally, the slit holes 21a and 29a are shifted from each other in the circumferential direction, and the water droplet intake port is closed. As shown in FIGS. 4 and 5, the probe 20 having the above structure is positioned at a required position of the low-pressure turbine, and the slit hole 21 of the outer cylinder 21 is oriented in a desired direction.
A is directed, and the shutter cylinder 29 is moved to adsorb water droplets in the steam flow to the mat member 23. When such a water drop collecting operation is appropriately performed in a necessary space area, the behavior or track pattern of the coarse water drops is measured and grasped.

[0004]

FIG. 9 (a) shows an example of the track distribution of water droplets at the mounting portion of the drain catcher 17 of the low-pressure turbine measured using the probe 20 and the like as described above. The slit holes 21a of the probe 20 inserted into the low-pressure turbine and the trace patterns A, B,
The relationship with C is shown in FIG. 7B, and it was found that there were many track patterns A and B. For this reason, as described above, in the conventional device having the slit 21a for taking in water droplets only on the side of the outer cylinder 21 of the probe 20, it is not possible to accurately measure the amount of water droplets for the water droplet flows of the track patterns A and B. It was difficult. Therefore, the object of the present invention is to
It is an object of the present invention to provide a coarse water droplet sampling probe that can appropriately and accurately collect a droplet in any direction and pattern in a gas-liquid two-phase flow such as wet steam.

[0005]

According to the present invention, there is provided a coarse water drop sampling probe for a steam flow in a turbine, wherein a continuous axial slit is formed on the side surface of the tip and the center of the tip surface. An outer cylinder, a shutter cylinder having a shutter slit which is removably and rotatably mounted in the outer cylinder and which is selectively aligned with the axial slit.
A rod-shaped support member provided in the shutter cylinder and supporting the moisture-absorbing mat member disposed inside the shutter cylinder from the inside of the axial slit and sliding on the base-side hollow shaft portion of the rod-shaped support member. An operation plunger freely inserted and connected to the shutter barrel, a positioning bracket fixedly provided at an inner tip of the outer barrel, and the positioning bracket attached to a tip of a support member extending through a tip face of the shutter barrel; , And a water drop circulation space is formed in the distal end portion of the shutter cylinder and the positioning fitting from the distal end portion of the axial slit toward the distal end portion of the moisture absorbing mat member.

[0006]

Embodiments of the present invention will be described below with reference to the accompanying drawings. Referring to FIGS. 1 and 2,
The outer tube 51 of the water drop probe 50 is formed by sequentially joining a guide tube 53, a slit tube 55, and a tip guide tube 57 by screwing or pin joining. A slit hole 55a extending in the axial direction is formed in the slit tube 55, and a slit hole 57a extending to the center position of the spherical distal end surface is formed in the distal end guide tube 57. The slit hole 55a and the slit hole 57a are shown in FIG. And so on. A positioning metal fitting 59 is provided at the distal end inside the distal end guide tube 57.
Has been fixed. The positioning metal fitting 59 has a cylindrical shape, and further has a slit hole 5 continuous with the slit hole 57a.
9a. On the other hand, a shutter cylinder 61 is removably inserted into the outer cylinder 51, which is
5a has a slit hole 61a that is selectively aligned, which further follows the slit hole 61b at the tip. A rod-shaped support member or support rod 65 having a guide tube 63 at the distal end which engages with the positioning metal fitting 59 to determine the direction is supported in the shutter cylinder 61 by bearings 67 and 69 so as to be relatively rotatable. A mat mounting base 71 is fixed in a slot portion 65a below the support rod 65 by mounting bolts 73, and a hygroscopic mat member 75 facing the slit hole 55a from inside is fixed to the mat mounting base 71. Further, the base end portion 65b of the support rod 65 has an axial space at the center portion, into which an operation plunger 77 similar to a conventional one is inserted so as to be relatively displaceable. The plunger 77 is connected to the shutter cylinder 61 by a connecting pin 79.

[0007] The method of using the water droplet probe 50 having the above-described configuration will be described. The water droplet probe 50 is put into a low-pressure turbine in a state as shown in Figs. When high-pressure air from an unillustrated air pipe acts on an unillustrated end of the operation plunger 75, the operation plunger 77 moves against the spring 81 and relatively displaces the shutter cylinder 61 downward. The shutter cylinder 61 rotates by a predetermined angle due to the mutual relationship with the non-rotating support bar 65, and the mat member 75 is exposed to the outside through the slit holes 55a and 57a as shown in the figure. Water droplets in the steam flowing around the water droplet probe 50 collide with the mat member 75 through the slit holes 55a and 57a and are adsorbed. Specifically, the water droplet of the upward steam flow flows upward through the slit hole 57a, further flows upward through the slit hole 59a of the positioning metal fitting 59 and the slit hole 61b at the tip of the shutter cylinder 61, and reaches the mat member 75. Adsorbed. When the predetermined sampling time has elapsed, the pressing of the operation plunger 77 by the high-pressure air is stopped. By doing so, the shutter cylinder 61 returns to the upper position, and the slit holes 55a and 57a are closed by the shutter cylinder 61.

[0008]

As described above, according to the present invention,
The axial slit, which is the water inlet for the probe, is formed not only on the side surface of the outer cylinder but also on the center of the tip surface, so that not only water droplets of the steam flowing horizontally in the low-pressure turbine but also those of the upward steam flow can be taken in. Therefore, there is no restriction due to the direction of the steam flow, and water droplets in a wide range of the steam flow can be appropriately adsorbed.

[Brief description of the drawings]

FIG. 1 is a partially cutaway partial cross-sectional view showing a main part of an embodiment of the present invention.

FIG. 2 is a partially cutaway front view corresponding to the cross-sectional view of FIG.

FIG. 3 is a conceptual sectional view showing an example in which water droplets of a gas-liquid two-phase fluid are measured by the device according to the present invention.

FIG. 4 is a conceptual cross-sectional view showing a situation where water droplets of a gas-liquid two-phase fluid are measured by the device according to the present invention.

FIG. 5 is a conceptual diagram corresponding to FIG.

FIG. 6 is a partial sectional view showing an example of a conventional probe.

FIG. 7 is a partially cutaway front view showing an example of a conventional probe.

FIG. 8 is a sectional view taken along line VIII-VIII in FIG.

FIG. 9 is a conceptual diagram showing a trace pattern of water droplets in a steam flow in a steam turbine.

[Explanation of symbols]

 Reference Signs List 50 probe 51 outer tube 53 guide tube 55 slit tube 55a slit hole 57 tip guide tube 57a slit hole 59 positioning fitting 59a slit hole 61 shutter tube 61a, 61b slit hole 63 guide tube 65 support rod 67, 69 bearing 71 mounting table 75 mat Material 77 Operation plunger

Claims (1)

[Claims] An outer cylinder having a continuous axial slit formed on a side surface of the distal end portion and a center of the distal end surface, and a shutter selectively removably and rotatably mounted in the outer cylinder and inserted in and removed from the outer cylinder. A shutter cylinder provided with a slit, a rod-shaped support member provided in the shutter cylinder for supporting a moisture-absorbing mat member disposed inside the shutter cylinder so as to face the axial slit, and a base end of the rod-shaped support member An operation plunger slidably inserted into the side hollow shaft portion and connected to the shutter cylinder, a positioning bracket fixedly provided at an inner distal end of the outer cylinder, and a support member extending through the distal end surface of the shutter cylinder A guide tube attached to a leading end for engaging with the positioning fitting, wherein the hygroscopic mat member is provided at the leading end of the shutter cylinder and the positioning fitting from the leading end of the axial slit. A water droplet circulation space is formed toward the tip of the turbine, and a coarse water droplet sampling probe for steam flow in a turbine characterized by being formed.