JPS5928001A - Gland steam controlling device of steam turbine - Google Patents

Abstract

PURPOSE:To prevent steam from blowing off to the outside of a steam turbine, or air from being sucked into the turbine from outside, by providing the pressure detecting point for a controller which controls each pressure control valve on the supply side and the exhaust side of a gland steam reservoir, at the inside port of a gland on the low pressure side. CONSTITUTION:A gland 7 for the high pressure side and a gland 8 for the low pressure side are respectively provided to both ends of a turbine shaft 6, which unitarily rotates with turbine blades 3, and pierces through a turbine wheel chamber 2, and the steam under the predetermined pressure is fed from a gland steam reservoir 19 to the inside ports 10 and 12 of each gland 7 and 8. In this case, the outside ports 9 and 11 of each gland 7 and 8 are connected to an exhaust passage 5, passing through an exhaust line 31 and a pressure control valve 32, and an exhaust line 17, respectively. The pressure control valve 32 is controlled by a controller 33 which responds to the pressure in the outside port 9. On the other hand, the pressure control valves 21 and 24 on the supply and the exhaust sides of the above-mentioned steam reservoir 19 are controlled by a controller 26 which responds to the pressure in the inside port 12.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a gland steam control device for a steam turbine that prevents steam from leaking to the outside in the gland of a labyrinth packing provided at a portion where a turbine shaft passes through a turbine casing 2. .

In a condensing turbine, the turbine rotor and turbine A labyrinth packing is provided between the turbine and the casing to minimize steam leakage from the high pressure section, and also sends sealing steam 7 to the low pressure gland to protect the turbine vacuum section from drawing in air.

The pressure of the sealing steam is slightly higher than atmospheric pressure (0,'[+5
~o, 15Ky/cdy), so the outermost port lag gland ejector of the high and low pressure gland section is
Below atmospheric pressure (-300
Generally, the water is sucked into the water (wnAq) and condensed using a ground condenser.

On the other hand, in small condensing turbines such as generator turbines for diesel ships, a method is adopted in which the gland steam is guided to the condenser without being equipped with a gland condenser in order to simplify the plant system. . In this case, it is necessary to control the gland steam so that it does not excessively blow out to the outside, and at the same time, prevents excessive air from being sucked into the turbine casing. In addition, in the case of diesel generator turbines for ships, for example, during voyages, low-pressure steam from an exhaust gas economizer is used in the middle, and during cargo handling, high-pressure steam and high output is often used from an auxiliary boiler. When conditions change significantly, manual fine adjustment of the sealing steam is required.

Such a conventional ground steam control device for a steam turbine will be explained with reference to FIG. 1. The steam pipe (11'!
'The steam that has passed through is introduced into the turbine casing (2) through a regulating valve, nozzle, etc. (not shown), and is then introduced into the turbine blade (3).
After being rotated to a low pressure, it is introduced into a condenser (not shown) through an exhaust port (4) and an exhaust passage (5). A turbine shaft (6) that rotates together with the turbine blade (3) passes through the turbine casing (2), and a high-pressure side gland (7) and a low-pressure side gland (8) are provided in the penetration part. ing. The high pressure side gland (7) is connected to the outer port (9).
) and an inner port (10) are formed, and an outer port 0υ and an inner port 0i are also formed in the low pressure side gland (8).

The outer port (9) of the high pressure side gland (7) is connected to line 0
1. Manual needle valve 04), line θ9, manual valve Q6)
It communicates with the exhaust passage (5) through 'a', and the outer port 0υ of the low pressure side gland (8) also connects to the line 0
η, manual needle valve α rotation line (one, connected to the exhaust passage (5) via the manual valve θθ).

(II is the grand steam reservoir, and steam is supplied from the line through the supply side pressure regulating valve (21). The grand steam reservoir It also communicates with the inner port α2 of the low-pressure side gland (8) by line c! Exhaust side pressure regulating valve 041. Exhaust passage (5
). 06), @ is a controller that receives the steam pressure in the grand steam reservoir 0!1, and controls the supply side pressure regulating valve CD and the discharge side pressure regulating valve Cl4.
Depending on the model, only one controller C! In some cases, the pressure regulating valve 61 controls both the supply side pressure regulating valve (211) and the discharge side pressure regulating valve Ca.

In the conventional device shown in FIG. 1 mentioned above, line C! In the low output region where the amount of leaked steam from (1 (Steam is supplied to I.

In addition, in the high output region where the amount of leaked steam from line y (221 is greater than the amount of steam supplied to line c21), the supply side pressure regulating valve Cll+ is fully closed, and the discharge side pressure regulating valve 041
is open and the steam line inside the grand steam reservoir ON (c),
The air is discharged through the exhaust passage (5) to a condenser (not shown).

In this way, the steam pressure in the grand steam reservoir H is controlled, so in the low output region the pressure in the grand steam reservoir 09 is reduced to the inner port O (1 becomes higher than the pressure of
On the other hand, in the high power region, the pressure in the grand steam reservoir (19) is lower than the pressure in the inner port ao+.As a result, the amount of steam leaking to Li/H changes, and in the low power region, the pressure in the grand steam reservoir (19) is lower than the pressure in the inner port ao+. In the output range, the opening degree of the manual needle valve α must be adjusted.
If the opening degree of 41 is kept constant (if the opening degree of Problems such as vacuum cracking of the condenser may occur due to excessive intake of air from the outside into the condenser.

The purpose of the present invention is to eliminate the need for such manual adjustment by moving the pressure detection point of the controller that controls the supply side pressure regulating valve and discharge side pressure regulating valve of the gland steam reservoir to the inside of the low pressure side gland. At the same time, a pressure regulating valve is installed in the exhaust line leading from the outer port of the high-pressure side gland to the exhaust passage, and this pressure regulating valve is controlled by a controller that receives pressure from the outer port of the high-pressure side gland. This invention relates to a ground steam control device for a steam turbine.

Next, one embodiment of the present invention will be described with reference to FIG. 2, using the same reference numerals for the same parts as in FIG. 1.

In Figure 2, the steam pipe (from 11 to the turbine casing (2)
The steam introduced therein rotates the turbine blades (3), becomes low pressure, and is introduced into a condenser (not shown) through an exhaust port (4) and an exhaust passage (5). The turbine shaft (6), which rotates together with the turbine blades (3), is the turbine casing (2).
The high-pressure side gland (7) and low-pressure side gland (8) of the through-hole part are connected to the outer port (9) and the inner port).
00 and an outer port) tll), an inner port Oz is formed. The outer port (01) of the low pressure side gland (8) communicates with the exhaust passage (5) via the line θD, the manual needle valve aυ, and the line +151'&.

O9 is a grand steam reservoir, and steam is supplied from the line (to) through the supply side pressure regulating valve (2+1'1%.The grand steam reservoir +11 is connected to the line (to)
Inner port of high pressure side gland (7) by 3)
It is also connected to the inner port (13) of the low pressure side gland (8) by line Q31. In order to adjust the steam pressure in the gland steam reservoir 09, the discharge side pressure regulating valve 04 is connected from the grand steam reservoir OI. , line (251) so that the air can be exhausted to the exhaust passage (5).

The outer port (9) of the high pressure side gland (7) is connected to the exhaust line 0υ and the exhaust passage (5) through the pressure regulating valve C3aya.
It is connected to the. This pressure regulating valve 03 is controlled by the controller ct1, and the controller (c) is connected to the outer port (9) of the high pressure side gland (7).
) pressure is being guided.

The aforementioned supply side pressure regulating valve 011, discharge side pressure regulating valve C,
Il is controlled by the controller country, @ °C, controller country, r5 is not subjected to the pressure of the gland steam reservoir 09 as in the conventional case, but is controlled by the inner port O3 of the low pressure side gland (8). The country is coming under increasing pressure. In addition, the controller ■, is 1 without 2 cages.
It is also possible to control both the supply-side pressure regulating valve Ca1l and the discharge-side pressure regulating valve Cn.

In the device shown in FIG. 2, the controller C6) receives pressure from the inner port f12 of the low-pressure side gland (81).
This controls the supply side pressure regulating valve Cυ and the discharge side pressure regulating valve B, and the inner port) +1'! Since the pressure of J is directly controlled, line C3 is controlled by changing the exhaust vacuum.
Even if the amount of steam in 1 changes, the inner port 03 remains in line c! It is not affected by the pressure loss of j and remains constant.

The pressure of +I[l (inner port of high pressure side gland (7)) is equal to the pressure of line C'3. Since the pressure is the sum of the pressure loss of C':1, the line C1+ due to the vacuum change at the exhaust port (4:
This system is affected by changes in pressure loss in line C22 due to changes in pressure loss in line c22 and changes in turbine load, so compared to the conventional system that is only affected by changes in pressure loss in line c22, Pressure change increases. However, in the system shown in Figure 2, the outside port (9
) is directly controlled by the pressure regulating valve C13, so it is not affected by pressure changes at the inner port 00.

Therefore, regardless of changes in steam conditions such as turbine load and exhaust vacuum, the outer port (
9) and the pressure at the inner port az of the low-pressure side gland (8) can both be controlled to be constant.

In the present invention, the supply side pressure regulating valve c! t+, by setting the pressure detection point of the discharge side pressure regulating valve C31 to the inner port Q2 of the low pressure gland (8) and directly controlling the pressure, the amount of steam leaking into the line H becomes constant. Therefore, by keeping the opening degree of the manual needle valve Ql constant, the pressure at the outer port (1υ) of the low pressure side gland (8) can be controlled to be constant.

In addition, the pressure change at the inner port θ1 of the high-pressure side gland (7) will be larger than in the conventional system because of the pressure loss in the line (c), but instead of the conventional manual needle valve 04), the pressure regulating valve 03 By providing '2, the pressure at the outer port (9) of the high pressure side gland (7) can be controlled to be constant.

In this way, regardless of changes in the turbine load or steam conditions, the pressures of the outer ports [91, (Ill) of the high-pressure side gland (7) and the low-pressure side gland (8) can be kept constant, so that steam is not blown to the outside. Or it can prevent heat from being sucked in from outside.

[Brief explanation of the drawing]

FIG. 1 is a system diagram of a conventional device, and FIG. 2 is a system diagram of an embodiment of the present invention. (2)...turbine casing, (5)...exhaust passage, (
6)...Turbine shaft, (7)...High pressure side gland,
(8)...Low pressure side ground, (91,Ql)...Outside port, 01. α2...inner port, (lI...
Grand steam reservoir, Ql)...supply side pressure regulating valve, (2
s, 6s...line, Q4...discharge side pressure regulating valve, shoes (c)...controller, 61)...discharge line, Zeng...pressure regulating valve. Patent applicant Ishikawajima Harima Heavy Industries Co., Ltd. @2 diagram

Claims (1)

[Claims] 1) An outer port and an inner port formed in the high-pressure side gland of the turbine shaft that penetrates the turbine casing, an outer port and an inner port formed in the low-pressure side gland of the turbine shaft, a grand steam reservoir, and the gland. a supply side pressure regulation valve and a discharge side pressure regulation valve of the steam reservoir; a line leading from the grand steam reservoir to the inner port of the high pressure side gland; and a line leading from the grand steam reservoir to the inner port of the low pressure side gland; A controller that receives the inner port pressure of the low-pressure side gland is provided with a controller that controls the supply-side pressure regulating valve and the discharge-side pressure regulating valve, an exhaust line that leads from the outer port of the high-pressure side gland to the exhaust passage, and a discharge line that is connected to the exhaust line. 1. A gland steam control device for a steam generator, comprising: a pressure regulating valve that receives external port pressure of the high-pressure side gland; and a controller that receives external port pressure of the high-pressure side gland and controls the pressure regulating valve.