阅读说明：本技术 发电设备以及发电设备的输出增加控制方法 (Power generation facility and output increase control method for power generation facility ) 是由 富山朋哉 于 2019-12-10 设计创作，主要内容包括：本发明提供一种发电设备以及发电设备的输出增加控制方法,在增加发电设备的发电输出的方面,不需要冷凝水贮存罐或能够使其容量变小,此外,不依赖于脱气机容量。发电设备具备锅炉(1)、涡轮机(2、3、4)、冷凝器(6)、供水加热器(9)、脱气机(10)、脱气机水位调节阀(30)、将从涡轮机抽出的蒸汽导入到供水加热器的抽气系统中设置的抽气阀(31),在该发电设备中设置辅助蒸汽导入系统(23),其向供水加热器(9)导入辅助蒸汽；辅助蒸汽调节阀,其设置在辅助蒸汽导入系统中,调节向供水加热器供给的蒸汽量,在请求急速增加负荷时,将抽气阀控制为关闭方向,将脱气机水位调节阀控制为维持开度,将辅助蒸汽调节阀控制为打开方向。(The invention provides a power plant and an output increase control method of the power plant, which can reduce the capacity of a condensate water storage tank and do not depend on the capacity of a deaerator in the aspect of increasing the power generation output of the power plant. The power generation facility is provided with a boiler (1), turbines (2, 3, 4), a condenser (6), a feed water heater (9), a deaerator (10), a deaerator water level regulating valve (30), and an extraction valve (31) provided in an extraction system for introducing steam extracted from the turbines into the feed water heater, and the power generation facility is provided with an auxiliary steam introduction system (23) for introducing auxiliary steam into the feed water heater (9); and an auxiliary steam regulating valve provided in the auxiliary steam introduction system, for regulating the amount of steam supplied to the feed water heater, and for controlling the suction valve to a closing direction, the deaerator water level regulating valve to maintain an opening degree, and the auxiliary steam regulating valve to an opening direction when a rapid load increase is requested.)

1. A power generation facility is provided with:

a steam generating device;

a turbine driven by the steam generated by the steam generator;

a condenser for condensing the steam discharged from the turbine into condensed water;

a water supply heater for heating the condensed water boosted by the condensing pump;

a deaerator for heating and deaerating the condensed water heated by the feed water heater;

a deaerator water level regulating valve for regulating a water level of the deaerator;

an extraction system for introducing the steam extracted from the turbine into the feedwater heater; and

an air extraction valve provided in the air extraction system,

it is characterized in that the preparation method is characterized in that,

the power generation facility includes:

an auxiliary steam introduction system for introducing auxiliary steam into the water supply heater;

an auxiliary steam adjusting valve provided in the auxiliary steam introduction system and adjusting an amount of steam supplied to the feed water heater; and

a control device for outputting opening command signals to the deaerator water level regulating valve, the extraction valve and the auxiliary steam regulating valve,

when a rapid load increase is requested to the power plant, the control device controls the extraction valve in a closing direction, controls the deaerator water level adjustment valve in a maintaining opening degree, and controls the auxiliary steam adjustment valve in an opening direction.

2. The power generation apparatus of claim 1,

a desuperheater for auxiliary steam is provided in an auxiliary steam supply pipe of the auxiliary steam introduction system.

3. The power generation apparatus of claim 1,

a pressure reducer for auxiliary steam is provided in the auxiliary steam supply pipe of the auxiliary steam introduction system.

4. An output increase control method for a power generation facility, the power generation facility comprising:

a steam generating device;

a turbine driven by the steam generated by the steam generator;

a condenser for condensing the steam discharged from the turbine into condensed water;

a water supply heater for heating the condensed water boosted by the condensing pump;

a deaerator for heating and deaerating the condensed water heated by the feed water heater;

a deaerator water level regulating valve for regulating a water level of the deaerator;

an extraction valve provided in an extraction system for introducing the steam extracted from the turbine into the feed water heater;

an auxiliary steam introduction system for introducing auxiliary steam into the water supply heater;

an auxiliary steam regulating valve provided in the auxiliary steam introduction system for regulating the amount of steam supplied to the feed water heater,

it is characterized in that the preparation method is characterized in that,

when a rapid load increase is requested to the power plant, the extraction valve is controlled to a closing direction, the deaerator water level adjustment valve is controlled to maintain an opening degree, and the auxiliary steam adjustment valve is controlled to an opening direction.

5. The output increase control method of a power generating apparatus according to claim 4,

and measuring the pressure in the feed water heater, and controlling the opening of the auxiliary steam regulating valve by using the pressure in the feed water heater as a control index.

6. The output increase control method of a power generating apparatus according to claim 4,

and measuring the flow rate of the extracted steam flowing through the extraction system, and controlling the opening degree of the auxiliary steam regulating valve by using the flow rate of the extracted steam as a control index.

Technical Field

The present invention relates to a power plant and an output increase control method for the power plant.

Background

In response to a request for a rapid load increase in the power output of the power plant, there is a control method called condensate throttling operation control (for example, patent document 1) in which an extraction valve and a deaerator water level adjustment valve are closed at a constant speed until a fixed opening degree is reached, and the power output is temporarily increased.

In the condensate throttling operation control, since the deaerator water level regulating valve is closed, the flow rate of condensate water downstream of the deaerator water level regulating valve is temporarily decreased, and the water level of the deaerator is lowered. Therefore, it is necessary to provide a deaerator having a capacity capable of compensating for a decrease in water level, and the provision of such a deaerator has a problem of increasing facility cost.

In order to avoid the rise of the water level in the condenser due to the closing control of the deaerator water level regulating valve, a condensate storage Tank (hereinafter referred to as CCST) for temporarily storing condensate water upstream of the deaerator water level regulating valve needs to be provided, and the provision of such CCST causes further increase in equipment cost.

Patent document 1: japanese patent laid-open publication No. 2013-53531

Disclosure of Invention

An object of the present invention is to provide a power plant and an output increase control method for the power plant, which can increase the power output of the power plant without requiring CCST or reducing the capacity thereof, and which do not depend on the capacity of a deaerator.

The power generation facility of the present invention includes: a steam generating device; a turbine driven by the steam generated by the steam generating device; a condenser for condensing steam discharged from the turbine into condensed water; a water supply heater for heating the condensed water boosted by the condensing pump; a deaerator for heating and deaerating the condensed water heated by the water supply heater; a deaerator water level regulating valve which regulates a water level of the deaerator; an extraction system that guides the steam extracted from the turbine to the feed water heater; and an extraction valve provided in the extraction system, the power generation apparatus being provided with: an auxiliary steam introduction system which introduces auxiliary steam to the water supply heater; and an auxiliary steam regulating valve provided in the auxiliary steam introduction system, for regulating the amount of steam supplied to the feed water heater, and for controlling the suction valve in a closing direction, maintaining the deaerator water level regulating valve in an opening degree, and controlling the auxiliary steam regulating valve in an opening direction when a rapid load increase is requested.

According to the present invention, in increasing the power output of the power generation facility, the CCST can be eliminated or the capacity thereof can be reduced, and an increase in power output independent of the capacity of the deaerator can be achieved, and as a result, an increase in facility cost can be suppressed.

Problems, structures, and effects other than those described above will become more apparent from the following description of the embodiments.

Drawings

Fig. 1 shows a configuration example of a power plant according to an embodiment of the present invention.

Detailed Description

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

Fig. 1 shows a configuration example of a power plant according to the present invention. In the drawings, the illustration of valves such as a main steam valve and other auxiliary machines such as a desalination device is omitted.

The power generation plant (steam turbine power generation plant) is constituted by: a boiler (steam generating apparatus) 1, a high-pressure turbine 2 driven by main steam from the boiler 1, an intermediate-pressure turbine 3 driven by reheat steam obtained by reheating exhaust steam of the high-pressure turbine 2 by the boiler 1, a low-pressure turbine 4 driven by exhaust steam of the intermediate-pressure turbine, and a generator 5 driven by the high-pressure turbine, the intermediate-pressure turbine, and the low-pressure turbine. The power plant is also provided with a condensation/water supply system including a condenser 6, a condensation pump 8, a low-pressure feed water heater 9, a deaerator 10, a feed water pump 11, a high-pressure feed water heater 12, and the like.

The extracted steam from the low-pressure turbine 4 is supplied to the low-pressure feed water heater 9 through the low-pressure extraction pipe 22. In the drawing, only one low-pressure feed water heater 9 is shown, but a plurality of low-pressure feed water heaters are provided as necessary. Further, the extracted steam from the intermediate-pressure turbine may be supplied to the low-pressure feed water heater on the rear stage side.

The extracted steam from the intermediate-pressure turbine 3 is supplied to the deaerator 10 via the 2 nd high-pressure extraction pipe 21. The extraction steam may be supplied to the deaerator 10 through a 1 st high-pressure extraction pipe 20 having an extraction position on the upstream side of the intermediate-pressure turbine 3.

The extracted steam is supplied to the high-pressure feed water heater 12 through a 1 st high-pressure extraction pipe 20 having an extraction position on the upstream side of the intermediate-pressure turbine 3. In the drawings, only one high-pressure feed water heater 12 is shown, but a plurality of high-pressure feed water heaters are provided as necessary. Further, the extracted steam from the high-pressure turbine may be supplied to the high-pressure feed water heater on the rear stage side.

A deaerator water level regulating valve 30 for regulating the water level of the deaerator 10 is provided in the condensing system on the upstream side of the deaerator 10. In the present embodiment, a deaerator water level regulating valve 30 is provided in the condensate pipe 7 downstream of the condensate pump 8. Further, an extraction valve 31 is provided in the low-pressure extraction pipe 22, and the extraction valve 31 is used to cut off the steam extracted from the low-pressure turbine or to adjust the amount of extracted steam.

In the present embodiment, an auxiliary steam introduction system for introducing auxiliary steam into the low-pressure feed water heater 9 is further provided. The auxiliary steam introduction system includes an auxiliary steam source 50 such as an in-system boiler, and an auxiliary steam supply pipe 23 for introducing steam from the auxiliary steam source 50 into the low-pressure feed water heater 9, and the auxiliary steam supply pipe 23 is provided with an auxiliary steam control valve 32 for controlling the amount of steam supplied to the low-pressure feed water heater 9. The boiler in the system is used for obtaining steam for driving a water supply pump-driven turbine, steam for cooling a steam turbine, steam for starting a deaerator, and the like, and has flexibility superior to that of the boiler 1.

In the present embodiment, a flow meter 41 for measuring the amount of steam to be extracted is provided in the low-pressure extraction pipe 22, and a pressure gauge 42 for measuring the pressure in the low-pressure feed water heater 9 is provided.

In the present embodiment, a control device 100 is provided, and the control device 100 receives as input a rise command signal, signals from the flow meter 41 and the pressure gauge 42, and outputs a fuel input command signal to the boiler 1, opening command signals of the deaerator water level adjusting valve 30, the suction valve 31, and the auxiliary steam adjusting valve 32, and the like.

Next, an embodiment of an output increase control method of a power plant according to the present invention will be described.

When a rapid load increase request is made to the power plant, the power plant configured as described above is controlled by the following method until the boiler load increases, and the rapid increase request of the power generation output is handled.

For example, when the system frequency is decreased in the power system, a 3% output increase command is output from the central power supply command or the like to the control device 100 of the power generation facility.

When receiving the 3% output increase command, the control device 100 outputs a close command to the extraction valve 31 and an open command to the auxiliary steam control valve 32. At this time, neither the off command nor the on command is output to the deaerator water level regulating valve to which the off command is input in the conventional condensate water throttling operation control, and the opening degree at that time point is maintained. At this time, the controller 100 outputs a boiler fuel input command to the boiler 1 to increase the fuel, thereby increasing the steam generation amount of the boiler 1.

By closing the extraction valve 31, the steam flow rate at the subsequent stage inside the low-pressure turbine 4 is increased by the amount of extraction flow rate reduction, whereby the power generation output is increased (achieving a 3% increase in power generation output).

In order to increase the steam generation amount of the boiler 1, an increase command is output for the feed water flow rate to the boiler 1. In the conventional condensate throttling control, the flow rate of condensate flowing into the deaerator is reduced by throttling the deaerator water level regulating valve, while the flow rate of feed water to be fed from the deaerator to the boiler pressure by the feed water pump is increased by the feed water flow rate increase command. As a result, in the conventional condensate throttling operation control, an imbalance occurs between the amount of feed water discharged from the deaerator (increase) and the amount of condensate water entering the deaerator (decrease), and the water level of the deaerator is lowered. Therefore, conventionally, a deaerator having a capacity capable of compensating for a drop in water level needs to be provided, and the facility cost is increased.

In this embodiment, the water level of the deaerator 10 is not lowered because the opening degree of the deaerator water level regulating valve 30 is maintained. Therefore, it is not necessary to increase the capacity of the deaerator 10 in terms of increasing the power generation output. That is, an increase in power generation output independent of deaerator capacity can be achieved. Further, even if the suction valve 31 is closed, the auxiliary steam regulating valve 32 is controlled to be opened to supply the auxiliary steam to the low-pressure feed water heater 9, so that the required feed water heating can be performed.

According to the embodiment of the present invention, during the operation of responding to the rapid load increase request, the deaerator water level adjustment valve 30 does not need to be closed, the flow rate of the condensed water flowing into the low-pressure feed water heater 9 can be kept constant, and the deaerator water level and the condenser water level do not change, so that the CCST can be reduced, and the deaerator capacity can be reduced.

In the boiler 1, when the boiler generated steam reaches a boiler generated steam amount that can increase the output by 3%, the operation for responding to the rapid load increase request is terminated. Specifically, an opening command signal is output from the control device 100 to the extraction valve 31 and the auxiliary steam control valve 32 so that the extraction valve 31 is returned to a normal opening and the auxiliary steam control valve 32 is closed.

Further, it is preferable to control the opening degree of the auxiliary steam adjusting valve 32 so as to compensate for the amount of extracted steam that decreases due to the closing operation of the extraction valve 31, based on the flow rate signal from the flow meter 41.

Further, it is preferable to control the opening degree of the auxiliary steam adjusting valve 32 so as to compensate for the pressure in the low-pressure feed water heater 9 which is lowered by the closing operation of the suction valve 31, based on the pressure signal from the pressure gauge 42.

Further, it is preferable that a desuperheater 60 or a decompressor 70 is provided in the auxiliary steam supply pipe 23 so that the temperature or pressure of the auxiliary steam from the auxiliary steam source 50 is equal to the temperature or pressure of the extracted steam.

The present invention is not limited to the above-described embodiments, and various modifications may be made. For example, the above-described embodiments are described in detail for the purpose of facilitating understanding of the present invention, and not necessarily all of the structures described. Note that a part of the structure of one embodiment may be replaced with the structure of another embodiment, or the structure of another embodiment may be added to the structure of one embodiment. Further, addition, deletion, and replacement of another structure may be performed for a partial structure of each embodiment.

Description of the symbols

1 … boiler, 2 … high-pressure turbine, 3 … medium-pressure turbine, 4 … low-pressure turbine, 5 … generator, 6 … condenser, 7 … condensation piping, 8 … condensation pump, 9 … feed water heater (low-pressure feed water heater), 10 … deaerator, 11 … feed water pump, 12 … high-pressure feed water heater, 20 … 1 st high-pressure extraction piping, 21 … nd 2 high-pressure extraction piping, 22 … low-pressure extraction piping, 23 … auxiliary steam supply pipe, 30 … deaerator water level regulating valve, 31 … extraction valve, 32 … auxiliary steam regulating valve, 41 … flow meter, 42 …, 50 … auxiliary steam source, 60 … desuperheater, 70 … decompressor, 100 manometer 100 … control device.