JPS62136218A - Apparatus for removing foreign matter in main steam of steam turbine - Google Patents

Abstract

PURPOSE:To remove the foreign matter in steam by utilizing inertial force, by connecting one contraction pipe receiving steam from a boiler to a branch pipe having two piping parts different in a radius of curvature. CONSTITUTION:A branch pipe 7 having a contraction pipe 6 is used between a boiler 1 and a steam turbine main steam stop valve 2. In starting a steam turbine, the steam stop valve 3 is fully closed at first and bypass valves 4, 5 are fully opened. Steam passing through the bypass valve 4 enters the contraction pipe 6 and respectively divided into steam containing impurities to piping 8 and clean steam containing no impurities to piping 9 by the difference of inertial force. Clean steam is introduced into the steam turbine through the bypass valve 5 and the main steam stop valve 2 and steam containing impurities is introduced into a cyclone separator 10. The clean steam from which foreign impurities were removed by the cyclone separator 10 is introduced into the inlet side of the main steam stop valve 2 or a boiler reheating steam system through piping 11 and the stop valve 12.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a device for removing foreign matter from steam flowing into a steam turbine.

2. Prior Art There is no precedent for such a technology, and the present invention is the only one.

Problems to be Solved by the Invention When the steam turbine is started, scale (mainly oxide film on the inner wall of the piping) in the boiler side pipes flies in and erodes the steam turbine nozzle, causing a decrease in turbine efficiency and an increase in maintenance costs. It becomes.

As a countermeasure to this problem, a method has been adopted in which the surface of the nozzle is coated with a hard material, but the current state of the art in the industry is that the coated surface erodes and peels off due to long-term operation and frequent start and stop operations.

The invention was made in order to solve Sophia's problems.
Installed between the boiler and the steam turbine main steam stop valve,
In a device for removing foreign matter from steam turbine main steam,
One condenser pipe that receives steam from the boiler is connected to a branch pipe that has two piping sections with different radii of curvature, and among these piping sections, a piping section that receives steam that is inertially separated and does not contain solid particles. is connected to the inlet side of the steam turbine main steam stop valve, and a piping section that receives steam containing solid particles is connected to a cyclone separator.

According to the device of the present invention described above, foreign matter is separated by the combination of the converging pipe and two pipes with different radii of curvature, and only steam without foreign matter mixed in is supplied to the steam turbine main steam stop valve. . The steam from which foreign matter has been removed by the cyclone separator is introduced into the steam turbine or boiler reheat system. Note that this system is used only when starting the steam turbine.

Embodiment As shown in FIG. 1, in a preferred embodiment of the present invention, a steam stop valve 3 is disposed in the piping from the boiler to the steam turbine before the steam turbine main steam stop valve 20.

A bypass valve 4 is provided by branching the upstream side of the steam stopper, that is, the boiler side, and this bypass valve 4 is connected to the flow contraction pipe 6. The contraction pipe 6 is connected to two pipes 8.9 via a branch pipe 7.
One pipe 9 returns to the downstream side of the steam stop valve 3 via the bypass valve 5. The other pipe 8 is connected to a cyclone separator 10. The outlet side of the cyclone separator 10 communicates with the inlet side of the main steam stop valve 20 or the boiler reheat steam system via a pipe 11 and a stop valve 12. There is a storage container 13 at the bottom of the cyclone separator.
is the provision.

Now, the most important parts of the device of the present invention are the contraction tube 6 and the branch tube 7.
FIG. 2 shows an enlarged view of the piping 8.9. The contracting flow tube 6 is a tube having a shape in which one side of the converging tube 6 is gradually reduced in diameter to form a section A, and a bifurcated branch tube 7 is connected to the tip thereof.

One piping section 8/ of this branch pipe 7 is a pipe section with a relatively large radius of curvature, and therefore receives the flow of steam mixed with solid particles that has been inertially separated by the flow contraction pipe 6. This is connected to the pipe 8. The other pipe section 9/ is a pipe section with a relatively small radius of curvature, and receives the flow of steam that has been removed by inertial separation of solid particles in the condenser pipe 6. This is connected to the pipe 9.

The operation of the device having such a configuration will be explained below.

In FIG. 1, the present invention is applied between a boiler 1 and a steam turbine main stop valve 2. In FIG. When starting the steam turbine, the steam stop valve 3 is fully closed, and the bypass valves 4 and 5 are fully opened. The steam that has passed through the bypass valve 4 enters the condenser pipe 6, and in the branch pipe 7, due to the solid particle inertial separation effect described below, the steam containing foreign matter goes to pipe 8, and the clean steam containing no foreign matter goes to pipe 9. be done. Clean steam is bypass valve 5
The steam containing foreign matter is introduced into the steam turbine through the main steam stop valve 2 and into the cyclone separator 10, respectively. The clean steam from which foreign matter has been removed again by the cyclone separator is introduced into the inlet side of the main steam stop valve 2 or the boiler reheat steam system through the pipe 11 and the stop valve 12.

Note that the separated foreign matter is stored in a container 13 provided at the bottom of the cyclone separator 10.

Figure 2 shows inertial separation of solid particles (Particle 5e).
(para-ratol) action. The foreign matter in the convergence tube 6 collides with the A part of the convergence tube 6, further collides with the B part of the branch pipe 7, and flows into the pipe 8 together with steam. On the other hand, the clean steam from which foreign substances have been removed is introduced into the pipe 9.

Note that the dotted line inside the branch pipe 7 indicates the trajectory of the colliding particles.

Further, the particle collision surfaces of the flow contraction pipe 6 and the branch pipe 70 are coated with a hard material.

When the degree of foreign matter flying from the boiler 1 becomes low, the steam stop valve 3
By interlocking the bypass valve 4.5 with the bypass valve 4.5, the former is opened and the latter is closed, and clean steam is supplied to the turbine through the original main steam piping system.

Effects of the Invention As described above, according to the present invention, it is possible to remove foreign matter that flows in from the boiler together with the steam when the steam turbine is started, when a lot of foreign matter is flying, and it is possible to prevent erosion of the steam turbine nozzle. Therefore, efficiency reduction and maintenance costs are reduced, and the reliability of the steam turbine is improved.

[Brief explanation of drawings]

Fig. 1 is a circuit diagram showing a preferred embodiment of the present invention, and Fig. 2 is a cross-sectional view showing a contracting flow pipe and a branch pipe, which are the main points of the present invention, together with particle trajectories during inertial separation of solid particles therein. It is. 1. Boiler, 2. Steam turbine main steam stop valve, 3.
・Steam stop valve, 4. Bypass valve, 5. Bypass valve,
6... Condenser pipe, 7... Branch pipe, 8... Piping, 81... Piping section, 9... Piping, 9'... Piping section (1 other person) Fig. 1

Claims (1)

[Claims] Installed between the boiler and the steam turbine main steam stop valve,
In a device for removing foreign matter from steam turbine main steam,
One condenser pipe that receives steam from the boiler is connected to a branch pipe that has two piping sections with different radii of curvature, and among these piping sections, a piping section that receives steam that is inertially separated and does not contain solid particles. An apparatus for removing foreign matter from main steam of a steam turbine, characterized in that a piping section that receives steam containing solid particles is connected to an inlet side of the steam turbine main steam stop valve, and a piping section that receives steam containing solid particles is connected to a cyclone separator.