JPS5813109A - Spray control method for steam turbine exhaust chamber - Google Patents

Abstract

PURPOSE:To effectively control temperature in the exhaust chamber in such a way that sprayed water particles are atomized by providing a pressure regulating valve by which sprayed water pressure in a spray nozzle is made appropriate through the temperature in an exhaust chamber. CONSTITUTION:A spray nozzle 6 is installed near the upper part of the final stage blades 3 in an exhaust chamber 1. Sprayed water 7 directly cools exhaust air flow and an exhaust chamber casing 5. Temperatures in the exhaust chamber are detected by command of a controller 11, with this taken as the working condition, sprayed water pressure is worked within the proper using of the spray nozzle 6 by means of a sprayed pressure regulating valve 10. Thus, at the same time as sprayed water particles can be prevented from coarsening, temperature in the exhaust chamber can be smoothly controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is directed to a leakage turbine exhaust chamber spray control method.

For example, in the case of a reheating turbine, the exhaust chamber spray operating conditions are expected to be low, such as the turbine load, ie, the exhaust flow rate, due to the control valve stroke in the case of a reheat turbine, the control valve stroke, etc. and spray water pressure aS. Therefore, regardless of the actual exhaust chamber St, there is a possibility that the spray will be injected even when it is not necessary.

In the first place, in the exhaust haze spray device, when the turbine has a low load and a low flow rate, the exhaust flow rate also decreases, so if the final stage of the turbine is a long blade, the exhaust temperature increases due to windage loss. The temperature rise in CO@Kitomi poses problems for turbines in the following ways: ■ The 11-degree rise in the exhaust chamber causes thermal deformation of the exhaust figs and casings, and as a result, the rotating and stationary parts Contact may cause damage or vibration.

(2)) If the bearing stand is integrated with the case V-ring, the case yy
The thermal deformation of the engine is due to the change in the alignment of the engine.
Ifllll and vibration generation 4DJ [Causes.

(3) An increase in the temperature of the exhaust chamber reduces the allowable stress of the rotor disk and blade group.

(4) If the connection between the cable and the condenser is made of rubber, an increase in the temperature of the exhaust chamber will cause m*0□ of the collar.

For the exhaust haze of the turbines with long blades in the above salt mountains, the amount of spray silver is essential.

However, as mentioned above, spray injection other than when necessary is undesirable for the turbine. That is, exhaust N
When the temperature is not high enough to cause a problem, the spray water increases the humidity in the exhaust chamber, thereby accelerating drain erosion of the blade OI, the implanted and effective parts, and the rotor. C-This g:'yo, issue, j@, O The lifespan will be shortened or it will cause the blade to fly off. In the case of using reheating pressure, regulating valve stroke, or constant load as the spray operating conditions as in JJ, rounding that indirectly predicts the exhaust chamber temperature, and from a safety point of view, the In reality, the current situation is that the sprayer starts operating when there is no need for the sprayer. In addition, even if the exhaust chamber temperature is set at 8% as a spray operating condition,
There is also a method of setting the spray flow rate control valve on the 11 degree control @aa to a certain level and turning it 0N-OFF, but due to the nature of the spray nozzle 04I, this is due to the lack of water pressure at low flow rates. Therefore, the spray water becomes water droplets with large particles, which is also undesirable from the standpoint of drain erosion.

This invention OI! The object of the present invention is to provide a steam turbine exhaust chamber spray control method that eliminates the above-mentioned drawbacks and exhibits an effective exhaust chamber spray effect.

To achieve the objectives of the invention, exhaust air equipped with spray water supply A/! ii degree is detected and this is set as an operating condition,
The present invention also relates to an exhaust spray control method for a steam turbine, characterized in that the spray water pressure is operated within an appropriate operating range of a spray nozzle using a spray water supply pressure valve.

Hereinafter, a description will be given of FIG. 2, which shows the control method of the present invention. Figure 2 shows a steam turbine O low-pressure exhaust car, which directs the exhaust flow (4) discharged from the exhaust 311 (13 is the most MR nozzle l) and the most #IR blade (3) to the lower part of the casing (5). This is intended to lead to a condenser (not shown). This exhaust chamber (1) is provided with a spray nozzle (6) near the top of the second stage as shown in the figure.

The spray water (7) injected from the spray nozzle (6) at
・111? The structure number corresponding to tj1 has been completed. In addition, in this case, the lower part of the case □ν song 3) and the shelf pedestal j81 are integrated, and the bearing (8) is located near the exhaust m (IJ).
The island of the exhaust chamber is affected by R-type O. For this reason, exhaust m
The electrical spray action in 1(1) may cause the above-mentioned bearing filament O breath, which may cause the receiving metal temperature and ring vibration, leading to plant shutdown.

In the present invention, the spray nozzle (6J ow control method) at the exhaust 31 m (1) is used, and as shown in Fig. Spray control is performed by position II.T
That is, the temperature of the exhaust chamber is detected by a command from the control device 10, and the spray water supply pressure is adjusted to the appropriate level of the spray nozzle using the spray water pressure m11 valve a@, using this as the operating condition. Figure 512 shows the relationship between spray water pressure CP) and spray flow rate (Q)O. Because of its 04I nature, the spray nozzle produces coarse particles at low water pressures, but when the pressure reaches a certain pressure of 21 or higher, good mold particles can be obtained. Also, in the relationship between spray water pressure and flow rate, water pressure P is slightly lower than water pressure P1,
! I can't get a proportional relationship between water pressure, flow rate, and O in the vicinity? ,
From the vicinity, a proportional relationship can be obtained. Next, FIG. 3 shows the relationship between spray water pressure P and exhaust temperature T. At the exhaust temperature T, the spray water pressure imm valve Q (l nozzle inlet water pressure Pi4 is adjusted to the same level.Furthermore, when the exhaust IK degree T1 or higher, the spray water pressure P at the exhaust chamber tIAF!JL upper limit T) is adjusted. Adjust so that it becomes !

Reference numeral 11411113 is a V-can for carrying out the exhaust spray control method of the present invention, and the control position a in Figure ll & 1 is the water pressure regulating valve ( 11) is exhaust type 1
Provided that Ili (Tc) is equal to or higher than the temperature (T1) in Diagram 3, and other conditions necessary for 6-spray operation are satisfied, -, the exhaust chamber m K (Tc) is fig
(Tt) @Th (and the water pressure regulating valve Ql is controlled to close under the condition that the exhaust temperature jic
(Tt ) to αd) from spray water pressure PM to P
, or proportionally controlled.

As described above, according to the present invention, it is easy to operate the spray when the reheat pressure, regulating valve stroke, or negative *'i* is independent of the conventional spray operation chamber temperature. It is possible to eliminate wasteful and costly spray operations at inopportune times. Also, Headquarters 111
4. Even if the operating condition is ms degree of exhaust as in the past, it is possible to operate the spray source valve 0N-OFF under a simple exhaust type temperature condition and prevent the spray water particles generated at the time of death from becoming coarse. One of the smoothest exhaust chambers! It becomes possible to control the degree.

[Brief explanation of the drawing]

11IlrIA is the location of the turbine exhaust chamber in which the a-chamber spray control method of the steam turbine of the present invention is carried out. Figure 2 is a relationship between spray water pressure and spray flow rate, 1/s
Figure s is a relationship diagram between spray water pressure and exhaust mold temperature, and Figure 4 is a sequence diagram for implementing the control method according to the present invention. l...Low pressure exhaust chamber 2...Final stage nozzle 3...Final stage nozzle 4...Exhaust flow 5...Casing 6...Spray nozzle 7...Spray water 8...Bearing 9...・・Water supply pipe lO ・Water pressure adjustment valve 11 ・・Control device (7317) Representative patent attorney Kensuke Norichika (and 1 other person) 1st
Figure 2 Figure 3 Pressure on surface 1.

Claims (1)

[Claims] Detecting the exhaust gas that is the installation of the spray nozzle,
A steam turbine exhaust chamber spray control method characterized in that this is the operating condition and the spray water pressure at which mold JiII particles are obtained is operated by a spray water supply O pressure regulating valve within the proper usage range of the spray nozzle.