JPH01300003A - Control device of degree of vacuum in condenser - Google Patents

Abstract

PURPOSE:To make the optimized control of the degree of vacuum of a condenser possible by controlling an inlet valve of driving steam by means of measuring the equivalent quantity of the steam volume ejected to the condensor and calculating the optimum quantity of driving steam in a device where air of the condensor is ejected by injection of steam. CONSTITUTION:A condenser 2 condenses steam (exhaust) ejected from a steam turbine 1, and incondensable gas, etc. in the exhaust are inducted to a steam injection type air extractor 3, maintaining the degree of vacuum in the condenser 2 at a specified level. In this occasion, a computing element 11 computes the volume of the exhaust from the turbin by the output of a motor 10, and the result of this computation enables a computing element 12 to determine the optimum degree of vacuum. A governing device 15 compares this optimum degree of vacuum with condenser's actual degree of vacuum detected by a transmitter 13, then, the volume of driving steam inducted to the extractor 3 is controlled by governing the opening of a driving steam inlet valve 6 through a controller 16 according to the deflection signal obtained.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to an air extraction system of a condenser of a steam turbine generator equipment, and relates to an air extraction system for a condenser of a steam turbine generator equipment, in which the suction performance of a steam injection air extractor is variable. The present invention relates to a condenser vacuum level control device that controls the vacuum level of a condenser.

(Prior Art) A conventional condenser extraction system equipped with a steam injection type air extractor is generally constructed as shown in FIG. Note that the steam injection type air extractor 3 shown in this figure is a two-stage, two-stage type. steam valve 8a
, 8b, 9a, 9b, the actuated steam inlet valve 6 is typically a manually or electrically actuated stop valve. The exhaust gas of the steam turbine 1 is condensed in a condenser 2. The non-condensable gas present in the exhaust gas of the steam turbine 1 and the air leaking from equipment and piping whose pressure drops below atmospheric pressure during operation of the steam turbine cycle are removed by the steam injection air extractor 3 via the air pipe 4. Emitted into the atmosphere. The drive steam pressure control valve 5 disposed in the drive steam line 20 is constantly controlled to maintain a secondary pressure of, for example, 14 atg.

The suction performance of the steam injection air extractor 3 is fixed because the steam pressure and steam amount in front of the drive steam inlet valve 6 are constant, and the degree of vacuum of the condenser is controlled by operating the drive steam inlet valve 6. What is to be done is not done.

(Problem to be solved by the invention) Recently, power generation equipment, especially thermal power generation equipment, has been forced to perform load adjustment operation. In the case of load adjustment operation, the turbine displacement changes, but conventionally, as mentioned above, the suction performance of the steam injection air extractor is constant, so the degree of vacuum in the condenser depends on the turbine displacement. and condenser cooling water temperature/
The value is determined from the condenser performance determined by the amount of cooling water and the performance of the steam injection air extractor.

Figure 2 is a diagram showing an example of the correlation between the turbine displacement and the effective degree of vacuum. It is necessary to adjust the vacuum level. However, in the past, turbines were not necessarily operated under the conditions of condenser vacuum that would result in the highest turbine efficiency.

The present invention improves the problems of the prior art described above.

It is an object of the present invention to provide a condenser vacuum degree control device with improved thermal efficiency.

[Structure of the invention]

(Means for Solving the Problems) A method for controlling the degree of vacuum in a condenser according to the present invention is to control the degree of vacuum in the condenser to the optimum degree of vacuum corresponding to the turbine displacement. The suction performance of the steam injection type air extractor is made variable by using the drive steam inlet valve of the steam injection device as a control valve to change the drive steam pressure and drive steam amount.

FIG. 3 is a diagram showing an example of the correlation between a change in the amount of driving steam of the steam injection type air extractor and the suction performance of the steam injection type air extractor.

In the case of the control device of the present invention, by throttling the drive steam inlet valve, the drive steam amount is reduced and the drive steam pressure is reduced. As shown, as the amount of driving steam decreases, the amount of air sucked into the steam injection air extractor decreases. Therefore, by effectively utilizing this feature, the suction performance of the steam injection air extractor is made variable so that the degree of vacuum in the condenser matches changes in the displacement of the turbine.

(Function) According to the condenser vacuum degree control method with the above configuration, 1. For example, during load adjustment operation, partial load operation, when the condenser cooling water temperature is lower than the design point of the condenser, etc. The degree of vacuum in the condenser can also be controlled so that the turbine efficiency is maximized, and thermal efficiency can be improved.

(Example) An example of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a system control method showing an embodiment of the condenser vacuum level control device according to the present invention. Note that the same elements as those in the conventional example shown in FIG. 4 are given the same reference numerals, and detailed explanation thereof will be omitted.

The output signal of the generator 10 is converted into a signal indicating the turbine displacement by a computing unit 11. The primary signal indicating the turbine displacement is converted into a signal indicating the optimum degree of vacuum by the computing unit 12. The signal indicating the optimum degree of vacuum is compared with the signal from the transmitter 13 which detects the degree of vacuum in the condenser 2 at the adjuster 15. The deviation signal obtained by the adjuster 15 is converted into a valve opening degree setting signal for the drive steam inlet valve 6 by the controller 16, and the drive steam inlet valve 6 is controlled. In this embodiment, the generator output signal is used to calculate the turbine displacement, but it is also possible to use other signals that can be easily converted into the turbine displacement, such as a condensate flow rate signal (not shown). .

[Brief explanation of the drawing]

Fig. 1 is a system diagram showing an embodiment of the condenser vacuum degree control device according to the present invention, Fig. 2 is a diagram showing an example of the correlation between turbine displacement and efficient vacuum degree, and Fig. 3 is a diagram showing an example of the correlation between the turbine displacement and the effective degree of vacuum. A diagram showing an example of the correlation between changes in the driving steam amount of an injection type air extractor and the suction performance of the steam injection type air extractor. Figure 4 shows a condenser equipped with a conventional steam injection type air extractor. FIG. 2 is a system diagram showing a vacuum degree control device. 1...Steam turbine 2...Condenser 3...Steam injection air extractor 4...Air pipe 5...Drive steam pressure control valve 6...Drive steam inlet valve 7a... Extraction air inlet valve 7
b... Extraction air inlet valve 8a, 8b... First stage steam valve 'Ja, 9b... Second stage steam valve 10... Generator 11... Arithmetic unit 12...
・Arithmetic unit 13... Pressure quadrature transmitter 14
...Pressure transmitter 15...Adjuster 16...Controller 2
0... Drive steam line agent Patent attorney Nori Ken Chika Yudo Daishimaru Ken Figure 1 Condenser Maki Return High Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] A condenser that condenses steam discharged from a steam turbine, a steam injection air extractor that discharges air from this condenser, and high-pressure steam that drives this air extractor. In a condenser vacuum degree control device that includes a supply drive steam line and a drive steam inlet valve disposed on the drive steam line, an amount equivalent to the amount of exhaust steam discharged from the steam turbine to the condenser is measured. means for calculating an optimum amount of driving steam corresponding to the equivalent amount of exhaust steam; and means for controlling a driving steam inlet valve to supply the optimum amount of driving steam to the air extractor. Features a condenser vacuum control device.