JPS61138809A - Auxiliary steam device for compound generating installation - Google Patents

Abstract

PURPOSE:To feed each plant with auxiliary steam in a well-balanced manner under various operation conditions, by controlling an auxiliary steam feeding flow control valve, which makes pressure inside an auxiliary steam header constant, on the basis of steam pressure at the auxiliary steam feeding side. CONSTITUTION:When steam pressure inside an auxiliary steam header 4 is varied, the auxiliary steam feed setting value obtainable out of outlet main steam pressure in a gas turbine exhaust gas boiler 1 is altered so as to keep steam pressure inside the auxiliary steam header 4 constant whereby actual flow setting is calculated, the actual flow setting after this alteration is compared with an actual auxiliary steam supply, and a pressure regulating valve 8 is opened or closed as far as a portion for the deviation. With this constitution, pressure inside the auxiliary steam header 4 is always kept constant. This control motion takes place at each plant, and the auxiliary steam quantity fed out of each plant is regulated to such one as performing an operating state that brings each plant into the best efficiency, thus a supply of the auxiliary steam quantity is made to be well balanced.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to an auxiliary steam device for a combined power generation facility, and in particular,
The present invention relates to an auxiliary steam device for a combined power generation facility that can improve operational efficiency by equalizing the flow direction of auxiliary steam supplied from each plant.

[Technical background of the invention and its problems]

In recent years, combined cycle power generation plants that combine a gas turbine cycle and a steam turbine cycle have often been formed, and combined cycle power generation plants that use a plurality of these combined cycle power generation plants to form one power generation facility have also been developed. has been adopted. As shown in Fig. 3, this combined cycle power generation equipment is a small-capacity combined cycle power generation system in which main steam obtained from a gas turbine exhaust gas boiler equipment 1 is guided to a steam turbine 2 to drive a generator 3. It has multiple plants. The optimum number of each combined cycle power generation plant is operated according to the load at the time, to ensure efficient operation.

In addition, auxiliary steam used for common equipment such as gas turbine fuel equipment and peripheral equipment for starting and stopping is supplied from an auxiliary steam system provided as common equipment for each plant. This auxiliary steam system collects a part of the main steam in each plant into a common auxiliary steam header 4, and transfers the steam in this auxiliary steam header 4 to peripheral equipment 5 and common equipment 6.
We are making sure to send them as appropriate.

In this case, a pressure regulating valve 8 is provided in the auxiliary steam supply pipe 7 connecting the gas turbine exhaust gas boiler equipment 1 in operation and the auxiliary steam header 4, and the auxiliary steam pressure to be supplied is reduced to a constant pressure. I try to do that. This ensures stable supply of auxiliary steam. This pressure reduction control is performed by the pressure regulator 11 based on the signal from the pressure detector 9.
This is done so that the steam pressure inside the auxiliary steam header 4 is always constant. The auxiliary steam supply pipe 7 is provided with a check valve 12 that prevents backflow of steam, and an electric valve 13 that stops the supply of steam. is provided with an electric valve 15 for stopping the supply of steam.

FIG. 4 shows the pressure regulator 11 in detail. That is, the pressure detection signal S1 from the pressure detector 9 is received by the deviation calculating section 16 of the pressure regulator 11, and is compared with the pressure setting signal S2 emitted from the setting pressure transmitter 17, and a deviation signal S3 between the two is obtained. is subjected to upper and lower limits by the proportional-integral-differential calculator 18, and then outputted to the pressure regulating valve 8 as a valve opening/closing signal S4.

However, in such a combined power generation facility, if the entire amount of auxiliary steam is supplied from one plant operating at rated capacity and the other plants are started, the pressure adjustment described above will not be performed even if each plant enters rated operation. 11 may not operate at all, and the supply of auxiliary steam may remain unbalanced. This is a phenomenon because the pressure detection values obtained by each pressure detector 9 do not change.

Furthermore, since the pressure loss of the piping system differs from plant to plant, an imbalance may occur in the amount of auxiliary steam supplied. That is, as shown in FIG.
(Horizontal axis) shows the characteristics (I.

If, III). Therefore, with respect to the pressure value Po in the ladder 4 to the auxiliary steam, the auxiliary steam supply amount f, f2. f3 was sometimes set.

Furthermore, since coefficients such as order constants and gains differ from plant to plant, an imbalance may occur in the amount of auxiliary steam supplied. That is, as shown in FIG. 6, because the pressure setting values (vertical axis) of each pressure regulating valve 8 are different, the auxiliary steam flow II (horizontal axis) has characteristics (I', II'.

■'). Therefore, with respect to the pressure value P0 in the auxiliary steam header 4, the auxiliary steam 5! differs for each plant! The quantities (I', I[', I') may occur.

In this way, if there is an imbalance in the amount of auxiliary steam supplied,
This affected the output of each plant, making it impossible to maintain uniform operation. If uniform operation became impossible, the overall efficiency of the power plant would decline and the lifespan of the equipment would be shortened.

[Purpose of the invention]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an efficient and reliable auxiliary steam pressure control device that eliminates the drawbacks of such combined power generation equipment, makes the amount of auxiliary steam supplied from each plant constant, and provides an efficient and reliable auxiliary steam pressure control device.

[Summary of the invention]

In order to achieve the above object, the auxiliary steam control device according to the present invention includes a function generator that issues a basic flow rate setting signal for the auxiliary steam flow rate based on the main steam pressure of each plant, and a function generator that generates a basic flow rate setting signal for the auxiliary steam flow rate based on the main steam pressure of each plant, and a pressure regulator that issues a set value change signal based on the basic flow rate setting signal and the set value change signal; a multiplier that issues an actual flow rate setting signal that should actually flow from each plant based on the basic flow rate setting signal and the set value change signal; The device is characterized by being equipped with a comparator that issues a valve opening/closing signal to the flow direction control valve based on the actual auxiliary steam flow value supplied from the plant, and the auxiliary steam is controlled based on the main steam pressure on the supply side. I try to adjust the pressure inside the header.

[Embodiments of the invention]

Embodiments of the present invention will be described in detail below with reference to the drawings.

In FIG. 1, in which the same components as those in FIG. It is input to the pressure regulator 21 and processed. A set value change signal S11 is sent from this pressure regulator 21 to the flow rate regulator 22 of each plant. Further, a flow meter 23 is provided immediately after the pressure control valve 8 of the auxiliary steam supply pipe 7.

A flow rate detector 24 is attached to this flow meter 23, and an actual flow rate signal S1□ representing the actual flow rate of auxiliary steam is emitted from the flow rate detector 24.

Furthermore, this actual flow rate signal S1□ is
This process was received and processed by
A valve opening/closing signal 813 is issued to the pressure regulating valve 8 from. Further, a pressure detector 25 is provided in the main steam pipe line of the gas turbine exhaust gas boiler equipment 1.
A pressure detection signal S14 from 5 is applied to the flow meter 22.

FIG. 2 shows details of the control section, and as shown in this figure, the pressure detection signal $1° from the pressure detector 20 is received by the comparison calculator 26 of the flow rate controller 21. .

Roughly speaking, a set pressure signal 815 from a set pressure signal transmitter 27 is applied to this comparison calculator 26, and the deviation from the pressure detection signal 810 is calculated. This deviation value is received as a deviation signal 316 by the proportional-integral-derivative calculator 28 and subjected to upper and lower limits, and a set value change signal S17 is issued to the multiplier 29 of the flow ffi controller 22. .

On the other hand, the pressure detection signal S14 from the pressure detector 25 is applied to the function generator 31 of the flow rate regulator 22, and the basic flow rate setting signal S18 corresponding to the pressure value of the main steam is output from this function generator 31. It looks like this. This basic style 1
The 11 setting signal s18 is received by the multiplier 29 and multiplied by the setting value change signal S1□. As a result, an appropriate flow layer value corresponding to both the steam pressure on the supply side (main steam side) and the steam pressure on the demand side (auxiliary steam header side) can be obtained, and this value is used as the actual flow rate setting signal S19 for deviation. The signal is issued to the arithmetic unit 32. Furthermore, the actual flow rate detection signal S12 from the flow rate detector 24 is applied to this deviation calculator 32, and the deviation between both signals S19 and 81□ is calculated. This deviation value is then sent to the proportional-integral-differential calculator 33 as a deviation signal S2°.
After the proportional integral differential calculation, the valve opening/closing signal S13
is emitted. The pressure regulating valve 8 is driven to open and close by the amount of this valve opening/closing signal S13.

In the auxiliary steam pressure control device having such a configuration, when the steam pressure in the auxiliary steam header 4, which is the steam demand side, fluctuates, the pressure changes depending on the main steam pressure at the outlet of the gas turbine exhaust gas boiler 1, which is the steam supply side. The control valve 8 is opened and closed.

That is, the pressure fluctuation within the auxiliary steam header 4 (signal 51o
), the set amount of auxiliary steam supply obtained from the main steam pressure (
signal 518) is changed to keep the steam pressure in the auxiliary steam header 4 constant (signal 519). The changed flow device setting W/i (signal 519) is compared with the actual auxiliary steam supply amount (signal S1□), and the pressure regulating valve 8 is adjusted by the difference. This allows the auxiliary steam header 4
The pressure inside is always kept constant.

Such *+w e operation is performed for each plant, and it is possible to keep the pressure in the auxiliary steam header 4 constant while maintaining the amount of auxiliary steam supplied according to the operating state of each plant. In other words, the auxiliary steam supply m sent from each plant is adjusted to an amount that allows each plant to always operate at its highest efficiency, and the amount of auxiliary steam supplied m is adjusted to avoid any imbalance in the auxiliary steam supply m. It can be prevented.

〔Effect of the invention〕

As described above, according to the present invention, in the auxiliary steam device of a combined cycle power generation facility that combines a plurality of combined cycle power plants, the auxiliary steam is opened and closed so that the pressure in the ladder to the auxiliary steam is maintained constant. Since the supply flow rate control valve is controlled based on the steam pressure on the auxiliary steam supply side, auxiliary steam can be supplied without causing imbalance between plants under various operating conditions. Therefore, the operating efficiency of each plant can always be maintained at its optimum level, and extremely high reliability and economic efficiency can be achieved.

[Brief explanation of drawings]

Fig. 1 is a system explanatory diagram of the combined power generation facility according to the present invention;
Fig. 3 is a block diagram showing the control circuit of the present invention, Fig. 3 is a system explanatory diagram of a conventional combined power generation facility, Fig. 4 is a block diagram showing a conventional control circuit, Figs. The figure is a diagram showing variations in the supply amount of auxiliary steam. 1... Gas turbine exhaust gas boiler equipment, 2... Steam turbine, 3... Generator, 4... Auxiliary steam header,
5... Peripheral equipment, 6... Common equipment, 7... Auxiliary steam supply pipe, 8... Flow rate control valve, 20... Pressure detector, 21... Pressure controller, 22...・Flow rate controller, 23
...Flow meter, 24...Flow rate detector, 25...Pressure detector, 26...Comparison calculator, 27...Setting pressure signal transmitter, 28.33...Proportional integral differential calculation vessel, 29
. . . Multiplier, 31 . . . Function generator, 32 . . . Deviation calculator. Applicant's Representative Inomata Section 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] In an auxiliary steam device for a combined cycle power generation facility that is equipped with a plurality of combined cycle power plants each having a gas turbine and a steam turbine, a part of the main steam of each plant is once collected in a common auxiliary steam header and used in various peripheral equipment, A function generator that issues a basic flow rate setting signal for the auxiliary steam flow rate based on the main steam pressure of each plant, a pressure controller that issues a set value change signal based on the steam pressure value in the auxiliary steam header, and the basic flow rate described above. A multiplier that issues an actual flow rate setting signal to be actually flowed from each plant based on a setting signal and a setting value change signal, and a valve opening/closing based on this actual flow rate setting signal and the actual auxiliary steam flow rate value supplied from each plant. An auxiliary steam device for a combined power generation facility, characterized by comprising a comparator and a comparator that issues a signal to a flow rate control valve.