JP2677616B2 - Condenser vacuum degree control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a condenser vacuum degree control device provided in a steam turbine power plant.

(Prior Art) FIG. 2 shows a configuration example of a conventional condenser vacuum degree control device. The steam sent from the steam generator to the steam turbine 2 via the main steam pipe 1 performs the work of rotating the generator 3, and then is introduced into the condenser 4 to be cooled and condensed to be condensed. It is sent to the deaerator side by the water pump 5. Cooling water circulates in the condenser 4 via a cooling water supply line 6. The degree of vacuum in the condenser 4 by the cooling water is controlled by the amount of cooling water supplied by the cooling water pump (hereinafter, referred to as CWP) 7. Reference numerals 8 and 9 are water chamber inlet / outlet valves provided in the cooling water supply line 6.

The wing angle of CWP7 is adjustable, and its opening is CW.
It is controlled based on a command from the P blade angle calculator 10.

Conventionally, such condenser vacuum control is generally regarded as an automated pattern control. That is, the output signal from the generator 3 and the cooling water temperature detection transmitter provided in the cooling water supply line 6
The detection signal from 11 is input to the CWP blade angle calculator 10.
In addition, the CWP blade angle calculator 10 has a control pattern program 1
The condition data signal for blade angle calculation from 2 is also input. The CWP blade angle is calculated based on these two series of signals, and C
CWP7 according to the control signal output from WP blade angle calculator 10
The wing angle of is increased or decreased.

By the way, as shown in FIG. 3, the contents of the control pattern program 12 represent the cooling water temperature on the vertical axis and the turbine output on the horizontal axis, and the required blade angle of the CWP 7 is set by the intersection thereof. However, as the setting elements of this program, in addition to the cooling water temperature and turbine output, the condenser performance curve,
Set target vacuum degree and CWP blade angle flow rate characteristic curve, etc.

(Problems to be Solved by the Invention) However, since the control pattern program 12 described above is created corresponding to a specific target degree of vacuum, an arbitrary degree of vacuum cannot be obtained. Therefore, when changing the degree of vacuum, Has the inconvenience of having to switch from automatic conditions to manual operation. Further, since the vacuum degree is not directly controlled, the range of the vertical error of the obtained vacuum degree becomes relatively large, and the operation is performed, for example, if the lower limit vacuum degree is satisfied, and it is not always possible to obtain a highly accurate vacuum degree. There is. Furthermore, very complicated calculations are required when creating the pattern program.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a condenser vacuum degree control device that can be controlled only by automatic operation, can obtain a highly accurate vacuum degree, and does not require complicated calculation. To aim.

[Configuration of the invention]

(Means for Solving the Problem) The present invention relates to a device for controlling the degree of vacuum of a condenser provided in a steam turbine plant, and a degree-of-vacuum detection transmitter provided in a condenser vacuum line and the degree of vacuum. An atmospheric pressure compensator that determines the actual degree of vacuum by correcting the output signal from the detection transmitter to the atmospheric pressure, and a turbine exhaust that is predetermined from the turbine exhaust volume that is obtained from the opening of the low-pressure steam control valve installed in the turbine. An optimum vacuum degree calculator for obtaining the optimum vacuum degree of the condenser by a function of the amount and the vacuum degree of the condenser, an optimum vacuum degree instruction signal from the optimum vacuum degree calculator, and a condenser water from the atmospheric pressure compensator. Calculating means for calculating the cooling water flow rate control value to the condenser using the actual vacuum degree signal as an element, and cooling water corresponding to the target condenser vacuum degree based on the control command output from this calculating means Control the flow rate in the line And a cooling water flow rate control device.

(Operation) In the calculating means, the cooling water flow rate control value is calculated based on the instruction signal of the optimum vacuum degree and the condenser vacuum degree signal subjected to the atmospheric pressure correction. The indicated value of the optimum vacuum degree is set corresponding to the turbine displacement. That is, the actual vacuum degree is directly controlled along the optimum point of the condenser vacuum degree according to the turbine operating condition. Therefore, a complicated calculation or the like unlike the conventional pattern control is not required. Further, automatic operation is performed according to the turbine displacement, and manual operation is not required. Then, a highly accurate vacuum degree can be obtained by the vacuum degree direct detection follow-up control.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

 FIG. 1 shows a first embodiment of the present invention.

Steam supplied through the main steam pipe 21 is steam turbine 22.
After being inflated in the inside and subjected to the work for the generator 23 rotation,
The condensed water is discharged to the condenser 24 and becomes condensed water, which is supplied to the deaerator side by the condensate pump 25. The cooling water line 26 that supplies the cooling water to the condenser 24 has a CWP2 as a cooling water supply control means.
7 are provided. Reference numerals 28 and 29 are water chamber inlet / outlet valves provided in the cooling water line 26.

The general control value of the condenser vacuum level is 722 mmHg, but the optimum vacuum point of the condenser changes depending on the turbine type, capacity, or the state of changes in operating load. For example, the turbine exhaust loss value changes depending on the turbine displacement, but a condenser vacuum degree that minimizes the loss value is required. That is,
The optimum vacuum degree changes greatly in a power generation facility where the load changes greatly or in a turbine where the turbine extraction amount changes drastically.

Therefore, in this embodiment, an exhaust amount calculator 37 is connected to the low pressure steam control valve 36 of the turbine 22 provided with the extraction pipe 21a, and the turbine displacement is obtained based on the opening signal output from the low pressure steam control pressure 36. I am trying. The exhaust amount signal output from the exhaust amount calculator 37 is input to the optimum vacuum degree calculator 38, and the optimum vacuum degree calculator 38 obtains the optimum vacuum degree based on the turbine discharge amount from the calculation data that has been input in advance. To be A vacuum degree detection transmitter 31 is provided in the vacuum line 30 of the condenser 24, and an atmospheric pressure compensator 32 is provided on the secondary side thereof.

An outlet valve opening degree instruction calculator 39 is provided as a means for calculating the flow rate control value. This outlet valve opening instruction calculator 39
The output signal from the optimum vacuum degree calculator 38 and the condenser actual vacuum degree signal that has passed through the atmospheric pressure compensator 32 are input to the. Then, based on these two series of signals, the outlet valve opening degree instruction calculator 39 obtains the outlet valve opening degree corresponding to the optimum degree of vacuum in accordance with the valve opening degree calculation data input in advance.
This output signal is a settling relay to avoid continuous operation 35
It is input to the water chamber outlet valve 29 via and is controlled to the optimum opening degree. As a result, the circulating amount of cooling water to the condenser 24 via the cooling water line 26 is determined, and the optimum vacuum degree is maintained.

According to the first embodiment as described above, the optimum vacuum degree corresponding to the load change can be obtained, and further, the vacuum degree according to the target value can be obtained by the direct detection control of the condenser vacuum degree. Therefore especially
It is suitable for power generation equipment that operates DSS (Daily Start Stop).

Although the cooling water flow rate is controlled by the opening of the water chamber outlet valve 29 in the first embodiment, it may be controlled by increasing or decreasing the blade angle of the CWP 27 in the second embodiment. In this case, the CWP blade angle calculator is used instead of the outlet valve opening instruction calculator of the first embodiment, and the actual vacuum degree signal from the atmospheric pressure compensator and the optimum vacuum degree instruction from the optimum vacuum degree calculator are used. Based on the signal, the CWP blade angle increase / decrease calculation is performed, and the operation signal increases / decreases the CWP blade angle. Therefore, the same control of the cooling water flow rate as in the first embodiment can be performed.

[Advantages of the Invention] As described above, according to the condenser vacuum degree control device according to the present invention, even in a power generation facility where the load change is large only by automatic operation or in a turbine where the turbine extraction amount changes drastically, it is optimal for the load change. The degree of vacuum can be obtained according to the target value, and the operation can be facilitated without requiring complicated calculation.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a first embodiment of a condenser vacuum degree control device according to the present invention, FIG. 2 is a block diagram showing a conventional example, and FIG. 3 is a pattern control diagram showing the operation of the conventional example. is there. 22 …… turbine, 24 …… condenser, 26 …… cooling water line,
27 …… CWP (cooling water flow controller), 29 …… water chamber outlet valve (cooling water flow controller), 30 …… vacuum line, 31 …… vacuum detection transmitter, 32 …… atmospheric pressure compensator, 38 ... Optimal vacuum degree calculator, 39 ... Outlet valve opening instruction calculator (calculation means).

Claims (1)

(57) [Claims] 1. An apparatus for controlling the degree of vacuum of a condenser provided in a steam turbine plant, wherein a vacuum degree detection transmitter provided in a condenser vacuum line and an output signal from the vacuum degree detection transmitter are provided. An atmospheric pressure compensator that determines the actual vacuum level by correcting the atmospheric pressure, and a turbine exhaust volume and the vacuum level of the condenser that are predetermined from the turbine exhaust volume that is obtained from the opening of the low-pressure steam control valve installed in the turbine. The optimum vacuum degree calculator for obtaining the optimum vacuum degree of the condenser by the function of, and the optimum vacuum degree instruction signal from the optimum vacuum degree calculator and the condenser actual vacuum degree signal from the atmospheric pressure compensator are used as elements. Calculation means for calculating the control value of the cooling water flow rate to the condenser, and cooling for controlling the flow rate in the cooling water line corresponding to the target condenser vacuum degree based on the control command output from this calculation means With water flow controller Condenser vacuum control device, characterized in that.