WO2021039311A1 - Boiler system, control method, and program - Google Patents

Boiler system, control method, and program Download PDF

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Publication number
WO2021039311A1
WO2021039311A1 PCT/JP2020/029843 JP2020029843W WO2021039311A1 WO 2021039311 A1 WO2021039311 A1 WO 2021039311A1 JP 2020029843 W JP2020029843 W JP 2020029843W WO 2021039311 A1 WO2021039311 A1 WO 2021039311A1
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WIPO (PCT)
Prior art keywords
temperature
pipe
steam
superheater
regulating valve
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PCT/JP2020/029843
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French (fr)
Japanese (ja)
Inventor
瞭 加藤木
一芳 伊藤
建聖 渡邊
Original Assignee
住友重機械工業株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
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Application filed by 住友重機械工業株式会社 filed Critical 住友重機械工業株式会社
Priority to KR1020227007447A priority Critical patent/KR20220053585A/en
Priority to JP2021542682A priority patent/JPWO2021039311A1/ja
Publication of WO2021039311A1 publication Critical patent/WO2021039311A1/en

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F22—STEAM GENERATION
    • F22G—SUPERHEATING OF STEAM
    • F22G5/00—Controlling superheat temperature
    • F22G5/12—Controlling superheat temperature by attemperating the superheated steam, e.g. by injected water sprays
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F22—STEAM GENERATION
    • F22B—METHODS OF STEAM GENERATION; STEAM BOILERS
    • F22B1/00—Methods of steam generation characterised by form of heating method
    • F22B1/02—Methods of steam generation characterised by form of heating method by exploitation of the heat content of hot heat carriers
    • F22B1/18—Methods of steam generation characterised by form of heating method by exploitation of the heat content of hot heat carriers the heat carrier being a hot gas, e.g. waste gas such as exhaust gas of internal-combustion engines
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F22—STEAM GENERATION
    • F22B—METHODS OF STEAM GENERATION; STEAM BOILERS
    • F22B37/00—Component parts or details of steam boilers
    • F22B37/02—Component parts or details of steam boilers applicable to more than one kind or type of steam boiler
    • F22B37/38—Determining or indicating operating conditions in steam boilers, e.g. monitoring direction or rate of water flow through water tubes

Definitions

  • the present invention relates to a boiler system, a control method and a program.
  • the temperature of the steam at the outlet of the boiler (the temperature of the steam discharged from the most downstream superheater: hereinafter referred to as the "main steam temperature”. ) Is raised.
  • the main steam temperature is raised, high-temperature steam flows through the superheater tube constituting the superheater, and as a result, the surface temperature of the superheater tube also becomes high.
  • the ash composed of chlorides and sulfides contained in the exhaust gas may be melted and adhered to the surface of the superheater tube to promote high temperature corrosion of the superheater tube.
  • Patent Document 1 lowers the surface temperature of the superheater tube by lowering the temperature of the exhaust gas, but a superheater (particularly a superheater arranged at the most downstream side) is used. Since extremely high temperature (for example, 541 ° C.) steam flows inside the constituent superheater tubes, it was not possible to efficiently reduce the surface temperature of the superheater tube simply by lowering the temperature of the exhaust gas.
  • the present invention has been made in view of such circumstances, and an object of the present invention is to suppress high-temperature corrosion of pipes by efficiently lowering the surface temperature of the pipes constituting the boiler system.
  • the boiler system according to the present invention has a pipe through which steam flows and a steam temperature control in which the temperature of the steam flowing through the pipe is lowered below a predetermined temperature by supplying a fluid inside the pipe. It is equipped with a part.
  • control method is a method of controlling the steam temperature of a boiler system including a pipe through which steam flows, and a temperature of steam flowing through the pipe is determined by supplying a fluid inside the pipe. It includes a steam temperature control step that lowers the temperature below the temperature.
  • the program according to the present invention is a program for causing a computer to execute a method of controlling the steam temperature of a boiler system including a pipe for circulating steam, and the method is a program in which a fluid is supplied to the inside of the pipe. It includes a steam temperature control step of lowering the temperature of steam flowing through the pipe below a predetermined temperature.
  • the temperature of the steam flowing through the pipe can be lowered below a predetermined temperature by supplying the fluid to the inside of the pipe, so that the temperature of the exhaust gas can be lowered more than the conventional method of lowering the temperature of the pipe.
  • the surface temperature can be lowered efficiently. Therefore, it is possible to suppress the adhesion of molten ash to the surface of the pipe and suppress the high temperature corrosion of the pipe.
  • the boiler system according to the present invention can be provided with a temperature detection unit that detects the steam temperature.
  • the steam temperature control unit controls the supply unit that supplies the fluid into the pipe, the adjustment valve that adjusts the amount of fluid supplied by the supply unit, and the adjustment valve based on the steam temperature detected by the temperature detection unit. By doing so, it is possible to have a control unit that controls the flow rate of the fluid supplied into the pipe.
  • the flow rate of the fluid supplied into the pipe can be controlled by the control unit by controlling the regulating valve based on the steam temperature detected by the temperature detection unit. Therefore, appropriate control can be performed according to the steam temperature.
  • the control unit controls the regulating valve so that when the steam temperature detected by the temperature detection unit exceeds a predetermined threshold value, the steam temperature in the pipe is lowered below the threshold value.
  • the threshold value can be set according to the state of ash adhering to the pipe and the fuel properties of the ash.
  • the control unit can control the regulating valve so that the steam temperature in the pipe is lowered below the threshold value.
  • a superheater having a first superheater, a second superheater downstream of the first superheater, and a third superheater downstream of the second superheater.
  • the pipes are the first connection pipe connecting the superheater pipe of the first superheater part and the superheater pipe of the second superheater part, and the superheater pipe of the second superheater part and the superheater of the third superheater part. It can include a second connecting pipe that connects to the pipe.
  • the temperature detection unit includes a first temperature sensor that detects the steam temperature at the inlet of the superheater tube of the second superheater, and a second temperature sensor that detects the steam temperature at the outlet of the superheater tube of the second superheater.
  • a third temperature sensor that detects the steam temperature at the inlet of the superheater tube of the third superheater, and a fourth temperature sensor that detects the steam temperature at the outlet of the superheater tube of the third superheater can be included.
  • the supply unit can include a pump that supplies fluid, a first water supply pipe that connects the pump and the first connecting pipe, and a second water supply pipe that connects the pump and the second connecting pipe.
  • the regulating valve may include a first regulating valve that regulates the supply amount of fluid supplied to the first connecting pipe and a second regulating valve that regulates the supply amount of fluid supplied to the second connecting pipe. It can. Then, the control unit controls the first regulating valve based on the steam temperature detected by the first temperature sensor and the second temperature sensor, thereby setting the steam temperature in the superheater tube of the second superheating unit as the first threshold value. By controlling the second regulating valve based on the steam temperature detected by the third temperature sensor and the fourth temperature sensor, the steam temperature in the superheater tube of the third superheater is set to the second threshold value. Can be lowered than. At this time, the second threshold value can be set to a value larger than the first threshold value.
  • the first regulating valve is controlled based on the steam temperature (steam temperature at the inlet and outlet of the superheater tube of the second superheater) detected by the first temperature sensor and the second temperature sensor.
  • the steam temperature in the superheater tube of the second superheater is lowered below the first threshold, and the steam temperature detected by the third temperature sensor and the fourth temperature sensor (the inlet of the superheater tube of the third superheater and
  • the steam temperature in the superheater tube of the third superheater can be lowered below the second threshold.
  • the second threshold value is set to a value larger than the first threshold value, it is possible to control so that the steam temperature gradually rises.
  • the boiler system according to the present invention can be provided with a reheater that reheats the steam discharged from the turbine.
  • the pipe may include a turbine bleed pipe connecting the turbine and the reheater pipe of the reheater.
  • the temperature detection unit includes an inlet temperature sensor that detects the steam temperature at the inlet of the reheater tube of the reheater and an outlet temperature sensor that detects the steam temperature at the outlet of the reheater tube of the reheater.
  • the supply unit can include a pump that supplies the fluid and a third water supply pipe that connects the pump to the turbine bleed pipe, and the regulating valve is for the fluid supplied to the turbine bleed pipe.
  • a third regulating valve that regulates the supply amount can be included. Then, the control unit controls the third regulating valve based on the steam temperature detected by the inlet temperature sensor and the outlet temperature sensor, so that the steam temperature in the reheater tube of the reheater is set to be higher than the third threshold value. Can be lowered.
  • the third regulating valve is re-controlled based on the steam temperature (steam temperature at the inlet and outlet of the reheater tube of the reheater) detected by the inlet temperature sensor and the outlet temperature sensor.
  • the steam temperature in the reheater tube of the heater can be lowered below the third threshold. Therefore, high temperature corrosion of the reheater tube of the reheater can be suppressed.
  • the boiler system 1 according to the first embodiment of the present invention is a circulating fluidized bed type system that burns fuel while circulating a circulating material (silica sand or the like) that flows at a high temperature to generate steam.
  • a circulating material silicon sand or the like
  • the fuel for the boiler system for example, non-fossil fuel (woody biomass, waste tires, waste plastic, sludge, etc.) can be used.
  • the steam generated in the boiler system 1 is used to drive the turbines 100 and 101, which will be described later.
  • the boiler system 1 is configured to burn fuel in the fireplace 2, separate the circulating material from the exhaust gas by a cyclone 3 functioning as a solid air separating device, and return the separated circulating material to the furnace 2 for circulation. ing.
  • the separated circulating material is returned to the lower part of the fireplace 2 via the circulating material recovery pipe 4 connected below the cyclone 3.
  • the lower part of the circulation material recovery pipe 4 and the lower part of the fireplace 2 are connected to each other via a loop seal portion 4a having a narrowed flow path as shown in FIG.
  • a predetermined amount of circulating material is stored in the lower part of the circulating material recovery pipe 4.
  • the exhaust gas from which the circulating material has been removed by the cyclone 3 is supplied to the rear flue 5 via the exhaust gas flow path 3a.
  • the fireplace 2 is a combustion furnace that burns fuel.
  • a fuel supply port 2a for supplying fuel is provided in the middle portion of the fireplace 2, and a gas outlet 2b for discharging combustion gas is provided in the upper portion of the fireplace 2.
  • the fuel supplied to the fireplace 2 from the fuel supply device (not shown) is supplied to the inside of the fireplace 2 via the fuel supply port 2a.
  • a furnace wall pipe 6 for heating the boiler water supply is provided on the furnace wall of the fireplace 2. The boiler water supply flowing through the furnace wall pipe 6 is heated by combustion in the furnace 2.
  • the combustion / flow air introduced from the lower air supply line 2c causes the solid matter including the fuel supplied from the fuel supply port 2a to flow, and the fuel flows while flowing, for example, about 800 to 900.
  • the combustion gas generated in the fireplace 2 is introduced into the cyclone 3 with a circulating material.
  • the cyclone 3 separates the circulating material and the gas by a centrifugal separation action, returns the circulating material separated through the circulating material recovery pipe 4 to the fireplace 2, and returns the combustion gas from which the circulating material has been removed to the exhaust gas flow path 3a. Is sent to the rear flue 5, which will be described later.
  • in-core bed materials solid substances called in-core bed materials are generated and accumulated at the bottom, and impurities (low melting point substances, etc.) are concentrated in the in-core bed material to cause sintering and melt solidification of the bed material, or non-combustible contamination. It is necessary to suppress malfunctions caused by objects. Therefore, in the fireplace 2, the bed material in the furnace is continuously or intermittently discharged to the outside from the discharge port 2d at the bottom. The discharged bed material is supplied to the fireplace 2 again after removing unsuitable substances such as metal and coarse particle size on a circulation line (not shown), or is discarded as it is.
  • the circulation material of the fireplace 2 circulates in the circulation system composed of the fireplace 2, the cyclone 3, and the circulation material recovery pipe 4.
  • the rear flue 5 has a flow path for flowing the gas discharged from the cyclone 3 to the rear stage.
  • the rear flue 5 has a superheater 10 for generating superheated steam and an economizer 20 for preheating the boiler water supply as an exhaust heat recovery unit for recovering the heat of the exhaust gas.
  • the exhaust gas flowing through the rear flue 5 is cooled by exchanging heat with steam and boiler water supply flowing through the superheater 10 and the economizer 20.
  • the rear flue 5 stores the pump 7 that supplies the boiler water supply to the economizer 20 and the boiler water supply that has passed through the economizer 20, and the steam drum connected to the furnace wall pipe 6 of the fireplace 2. It has 8 and.
  • the configuration of the superheater 10 will be described in detail later.
  • the economizer 20 transfers the heat of the exhaust gas to the boiler water supply to preheat the boiler water supply.
  • the economizer 20 is connected to the pump 7 by a pipe 21 while being connected to the steam drum 8 by a pipe 22.
  • the boiler water supplied from the pump 7 to the economizer 20 via the pipe 21 and preheated by the economizer 20 is supplied to the steam drum 8 via the pipe 22.
  • a precipitation pipe 8a and a furnace wall pipe 6 are connected to the steam drum 8.
  • the boiler water supply in the steam drum 8 descends from the precipitation pipe 8a, is introduced into the furnace wall pipe 6 on the lower side of the furnace 2, and flows toward the steam drum 8.
  • the boiler water supply in the furnace wall pipe 6 is heated by the combustion heat generated in the furnace 2 and evaporates in the steam drum 8 to become steam.
  • An exhaust pipe 8b for discharging internal steam is connected to the steam drum 8.
  • the exhaust pipe 8b connects the steam drum 8 and the superheater 10.
  • the steam in the steam drum 8 is supplied to the superheater 10 via the exhaust pipe 8b.
  • the superheater 10 uses the heat of exhaust gas to superheat steam to generate superheated steam.
  • the superheated steam passes through the pipe 10a and is supplied to the turbines 100 and 101 outside the boiler system 1 to be used for power generation.
  • the superheater 10 includes a first superheater section 11 that superheats the steam introduced from the exhaust pipe 8b, and a second superheater section 12 that further superheats the steam introduced from the first superheater section 11. , A third superheater 13 that further superheats the steam introduced from the second superheater 12.
  • the first superheater section 11, the second superheater section 12, and the third superheater section 13 each have superheater tubes 11a, 12a, and 13a for passing steam. Further, the first superheated portion 11 and the second superheated portion 12 are connected by a first connecting pipe 14, and the second superheated portion 12 and the third superheated portion 13 are connected by a second connecting pipe 15.
  • the second overheat A second temperature sensor 16b for detecting the steam temperature T 2 at the outlet of the superheater tube 12a of the unit 12 is provided.
  • a third temperature sensor 16c is provided for detecting the steam temperature T 3 at the inlet of the superheater tubes 13a, on the downstream side of the third superheated portion 13, superheated fourth temperature sensor 16d for detecting the steam temperature T 4 at the outlet of the organ 13a.
  • Information on the steam temperature detected by the first temperature sensor 16a, the second temperature sensor 16b, the third temperature sensor 16c, and the fourth temperature sensor 16d is sent to the control unit 30 described later and used to control various control valves. ..
  • the first temperature sensor 16a, the second temperature sensor 16b, the third temperature sensor 16c, and the fourth temperature sensor 16d correspond to the temperature detection unit in the present invention.
  • the first connection pipe 14 that connects the first superheated portion 11 and the second superheated portion 12 is connected to the pump 7 by the first water supply pipe 7a, and connects the second superheated portion 12 and the third superheated portion 13.
  • the two connecting pipes 15 are connected by a second water supply pipe 7b.
  • water for steam cooling is supplied from the pump 7 to the first connecting pipe 14 via the first water supply pipe 7a, and is supplied from the pump 7 to the second connecting pipe 15 via the second water supply pipe 7b.
  • the first water supply pipe 7a and the second water supply pipe 7b have a common pipe portion 7ab on the upstream side (pump 7 side).
  • the pump 7 and the first and second water supply pipes 7a and 7b correspond to the supply unit in the present invention.
  • the first water supply pipe 7a connecting the pump 7 and the first connection pipe 14 is provided with a first adjustment valve 18 for adjusting the flow rate of water flowing through the first water supply pipe 7a, and the pump 7 and the first water supply pipe 14 are provided.
  • the second water supply pipe 7b that connects the two connection pipes 15 is provided with a second adjustment valve 19 that adjusts the flow rate of water flowing through the second water supply pipe 7b.
  • the first regulating valve 18 and the second regulating valve 19 adjust the amount of water supplied to the first connecting pipe 14 and the second connecting pipe 15 by being controlled by a control signal sent from the control unit 30 described later. Works like.
  • the boiler system 1 includes a control unit 30 that integrally controls various configurations provided in the system.
  • the control unit 30 is composed of a memory for storing various control programs, various control data, and the like, a processor for executing various control programs, and the like.
  • the control unit 30 first is based on the steam temperatures T 1 , T 2 , T 3 , and T 4 detected by the first temperature sensor 16a, the second temperature sensor 16b, the third temperature sensor 16c, and the fourth temperature sensor 16d. By controlling the regulating valve 18 and the second regulating valve 19, the flow rate of water supplied into the first connecting pipe 14 and the second connecting pipe 15 is controlled. More specifically, the control unit 30 has steam temperatures T 1 and T 2 (steam at the inlet and outlet of the superheater tube 12a of the second superheater 12) detected by the first temperature sensor 16a and the second temperature sensor 16b.
  • the first and second thresholds T 12 and T 34 are used for the ash adhesion status, the component analysis values of fuel and combustion ash, the ash adhesion status to the pipe at the time of periodic inspection, the corrosion status of the pipe, and the like. It is a value appropriately determined based on, for example, the melting point of ash contained in the exhaust gas, the specific temperature set by the requirements of the turbine 100 connected to the boiler system 1 and the 101 side, and the like are adopted as predetermined threshold values. be able to.
  • the fuel may contain alkali metals (sodium, potassium, etc.), and the chlorides and sulfides produced by chlorine, sodium, potassium, etc. are the combustion field temperature (about 870) in the furnace 2.
  • the first and second thresholds T 12 and T 34 are preferably determined as appropriate in consideration of the low melting points of these substances. Similarly, the threshold value in the second embodiment described later is also appropriately determined.
  • the pump 7, the first and second water supply pipes 7a and 7b (supply unit), the first adjustment valve 18, the second adjustment valve 19, and the control unit 30 in the present embodiment provide the first connection pipe 14 and the first connection pipe.
  • a "steam temperature control unit" that lowers the temperature of the steam flowing through the first connecting pipe 14 and the second connecting pipe 15 below a predetermined temperature is configured. ..
  • a turbine (turbine 100 and turbine 101 arranged coaxially) is connected to the boiler system 1 according to the present embodiment.
  • Steam is supplied to the turbine 100 from the superheater 10 through the pipe 10a, and steam (reheated steam) from the reheater 40 described later is supplied to the turbine 101, whereby the turbines 100 and 101 rotate.
  • the pressure and temperature of the steam discharged from the turbine 100 is lower than the pressure and temperature of the steam discharged from the superheater 10.
  • the pressure of the steam supplied to the turbine 100 is about 10 to 17 MPa, and the temperature is about 530 to 570 ° C.
  • the pressure of the steam discharged from the turbine 100 is about 3 to 5 MPa, and the temperature is about 350 to 400 ° C.
  • a condenser 102 is provided downstream of the turbine 101. The steam discharged from the turbine 101 is supplied to the condenser 102, condensed in the condenser 102, returned to saturated water, and then supplied to the pump 7.
  • the boiler system 1 includes a reheater 40 that reheats the steam discharged from the turbine 100.
  • the reheater 40 has a reheater tube 40a for circulating steam.
  • the turbine 100 and the reheater 40 are connected by a turbine bleeding pipe 100a for supplying the steam discharged from the turbine 100 to the reheater 40.
  • the reheater 40 and the turbine 101 are connected by a turbine air supply pipe 101a for supplying the steam reheated by the reheater 40 to the turbine 101. Therefore, the steam supplied to the reheater 40 via the turbine bleeding pipe 100a is reheated by heat exchange in the reheater 40 and then supplied to the turbine 101 on the downstream side via the turbine air supply pipe 101a.
  • the upstream side of the reheater 40, and the inlet temperature sensor 51 is provided for detecting the steam temperature T 5 at the inlet of the reheater tubes 40a, on the downstream side of the reheater 40, reheater tubes 40a
  • An outlet temperature sensor 52 for detecting the steam temperature T 6 at the outlet of the above is provided.
  • the inlet temperature sensor 51 and the outlet temperature sensor 52 also correspond to the temperature detection unit in the present invention. Information about the steam temperature detected by the inlet temperature sensor 51 and the outlet temperature sensor 52 is sent to the control unit 30 and used for controlling the third regulating valve 60, which will be described later.
  • the turbine bleeding pipe 100a connecting the turbine 100 and the reheater 40 is connected to the pump 7 by a third water supply pipe 7c branching from the second water supply pipe 7b, and the water for steam cooling is supplied to the pump 7. Is supplied to the turbine bleeding pipe 100a (and by extension, the reheater pipe 40a) via the third water supply pipe 7c.
  • the pump 7 and the third water supply pipe 7c correspond to the supply unit in the present invention.
  • the third water supply pipe 7c is provided with a third regulating valve 60 that adjusts the flow rate of water flowing through the third water supply pipe 7c.
  • the third regulating valve 60 functions to adjust the amount of water supplied to the turbine bleeding pipe 100a (reheater pipe 40a) by being controlled by a control signal sent from the control unit 30.
  • the control unit 30 controls the third regulating valve 60 based on the steam temperatures T 5 and T 6 detected by the inlet temperature sensor 51 and the outlet temperature sensor 52, thereby controlling the turbine bleeding pipe 100a (reheater pipe 40a). Control the flow rate of water supplied inside. More specifically, the control unit 30 determines the turbine bleeding pipe when the average value of the steam temperatures T 5 and T 6 detected by the inlet temperature sensor 51 and the outlet temperature sensor 52 exceeds the third threshold value T 56.
  • the third regulating valve 60 is controlled so as to be lower than the threshold value T 56.
  • the third threshold value T 56 is a value appropriately determined based on the adhesion state of ash and the like, similarly to the first and second threshold values T 12 and T 34.
  • Water is supplied to the inside of the turbine bleeding pipe 100a (reheater pipe 40a) by the pump 7, the third water supply pipe 7c (supply unit), the third regulating valve 60, and the control unit 30 in the present embodiment.
  • a "steam temperature control unit” that lowers the temperature of the steam flowing through the turbine bleeding pipe 100a (reheater pipe 40a) below a predetermined temperature is configured.
  • the control unit 30 of the boiler system 1 detects the steam temperatures T 1 and T 2 at the inlet and outlet of the superheater tube 12a of the second superheating unit 12 by using the first temperature sensor 16a and the second temperature sensor 16b.
  • (1st and 2nd temperature detection step: S1) using the 3rd temperature sensor 16c and the 4th temperature sensor 16d, the steam temperatures T 3 and T at the inlet and outlet of the superheater tube 13a of the third superheating unit 13. 4 is detected (third and fourth temperature detection steps: S2).
  • control unit 30 detects the steam temperatures T 5 and T 6 at the inlet and outlet of the reheater tube 40a of the reheater 40 by using the inlet temperature sensor 51 and the outlet temperature sensor 52 (inlet / outlet temperature detection). Step: S3).
  • the control unit 30 of the boiler system 1 determines the first regulating valve when the average value of the steam temperatures T 1 and T 2 detected in the first and second temperature detection steps S1 exceeds the first threshold value T 12.
  • the steam temperature in the first connecting pipe 14 is lowered, and as a result, the superheater pipe 12a of the second superheating portion 12
  • the steam temperature T 1 at the inlet of the above is lowered below the first threshold value T 12 (first steam temperature control step: S4).
  • the control unit 30 controls the second regulating valve 19 when the average value of the steam temperatures T 3 and T 4 detected in the third and fourth temperature detection steps S2 exceeds the second threshold value T 34.
  • the steam temperature in the second connecting pipe 15 is lowered, and as a result, the steam at the inlet of the superheater pipe 13a of the third superheater portion 13
  • the temperature T 3 is lowered below the second threshold T 34 (second steam temperature control step: S5).
  • the control unit 30 controls the third regulating valve 60 to control the turbine when the average value of the steam temperatures T 5 and T 6 detected in the inlet / outlet temperature detection step S3 exceeds the third threshold value T 56.
  • the control mode of the first regulating valve 18 (second regulating valve 19) is not limited to this.
  • the first regulating valve is based on the difference in steam temperatures T 1 , T 2 (T 3 , T 4 ) at the inlet and outlet of the superheater tube 12a (13a) of the second superheater 12 (third superheater 13).
  • 18 (second regulating valve 19) can also be controlled.
  • FIG. 4 shows an example of a change in the steam temperature of the boiler system 1 according to the present embodiment.
  • the boiler water supply is preheated by the heat of the exhaust gas, raised to a predetermined temperature, and supplied to the steam drum 8.
  • the steam of the boiler supply water supplied to the steam drum 8 is heated by the combustion of the fireplace 2, and is supplied to the first superheater 11 of the superheater 10 in a state where the temperature has risen to the saturated steam temperature.
  • the steam supplied to the first superheated section 11 is supplied to the second superheated section 12 via the first connecting pipe 14 in a state of being superheated to, for example, a steam temperature of about 450 ° C. by the heat of the exhaust gas.
  • the control unit 30 controls the first regulating valve 18 to supply water into the first connecting pipe 14, thereby lowering the steam temperature in the first connecting pipe 14.
  • the control unit 30 controls the first regulating valve 18 based on the steam temperatures T 1 and T 2 at the inlet and outlet of the superheater tube 12a of the second superheater unit 12, and first. lowering the steam temperature in the first connecting pipe 14 by controlling the flow rate of water supplied to the connecting pipe 14, as a result, the steam temperatures T 1 at the inlet of the superheater tubes 12a of the second heating section 12 It is lower than the first threshold T 12.
  • the first threshold value T 12 used for controlling the first regulating valve 18 can be appropriately set according to the target main steam temperature (temperature of steam to be supplied to the turbine 100).
  • the first threshold value T 12 used for controlling the first regulating valve 18 is also a relatively high value (for example, about 450 ° C.). ). Then, as shown in the graph G 1 on the 4, the steam temperatures T 1 at the inlet of the second heating unit 12 is adjusted to a temperature lower than the first threshold T 12.
  • the target main steam temperature is a relatively low value (for example, about 500 ° C.)
  • the first threshold value T 12 used for controlling the first regulating valve 18 is also a relatively low value (for example, about 400 ° C.).
  • the steam temperature T 1 at the inlet of the second superheated portion 12 is adjusted to a temperature lower than the first threshold value T 12. In this way, in either case, the temperature of the steam flowing in the first connecting pipe 14 can be lowered, and the temperature of the steam flowing in the superheater pipe 12a of the second superheater portion 12 can also be lowered. Can be done.
  • control unit 30 controls the second regulating valve 19 to supply water into the second connecting pipe 15 to lower the steam temperature in the second connecting pipe 15.
  • the control unit 30 controls the second control valve 19 based on the steam temperature T 3, T 4 at the inlet and outlet of the superheater tube 13a of the third superheated portion 13 lowering the steam temperature of the second connecting pipe 15 by controlling the flow rate of water supplied into the connection tube 15, as a result, the steam temperature T 3 at the inlet of the superheater tubes 13a of the third superheated portion 13 Lower than the second threshold T 34.
  • the second threshold value T 34 used for controlling the second regulating valve 19 can be appropriately set according to the target main steam temperature (temperature of steam to be supplied to the turbine 100).
  • the second threshold value T 34 used for controlling the second regulating valve 19 is also a relatively high value (for example, about 500 ° C.).
  • steam temperature T 3 at the inlet of the third superheated portion 12 is adjusted to a temperature lower than the second threshold T 34.
  • the target main steam temperature is a relatively low value (for example, about 500 ° C.)
  • the second threshold value T 34 used for controlling the second regulating valve 19 is also a relatively low value (for example, about 450 ° C.).
  • steam temperature T 3 at the inlet of the third superheated portion 13 is adjusted to a temperature lower than the second threshold T 34. In this way, in either case, the temperature of the steam flowing in the second connecting pipe 15 can be lowered, and the temperature of the steam flowing in the superheater pipe 13a of the third superheater portion 13 can also be lowered. Can be done.
  • the steam temperature flowing through the pipes is set by supplying water to the inside of the pipes (first connecting pipe 14, second connecting pipe 15, reheater pipe 40a). Since the temperature can be lowered below a predetermined temperature, the surface temperature of the pipe can be lowered more efficiently than the conventional method of lowering the temperature of the exhaust gas. Therefore, it is possible to suppress the adhesion of molten ash to the surface of the pipe and suppress the high temperature corrosion of the pipe.
  • the temperature detection unit (first temperature sensor 16a, second temperature sensor 16b, third temperature sensor 16c, fourth temperature sensor 16d, inlet temperature sensor 51, outlet temperature). Adjustment valves (first adjustment valve 18, second adjustment valve 19, third adjustment valve) based on the steam temperature (T 1 , T 2 , T 3 , T 4 , T 5 , T 6 ) detected by the sensor 52). By controlling 60), the flow rate of water supplied into the pipes (first connecting pipe 14, second connecting pipe 15, reheater pipe 40a) can be controlled by the control unit 30. Therefore, appropriate control can be performed according to the steam temperature.
  • the control valve 30 can control the regulating valve so as to reduce the temperature.
  • the steam temperature detected by the first temperature sensor 16a and the second temperature sensor 16b (the steam temperature at the inlet and outlet of the superheater tube 12a of the second superheater portion 12).
  • the first regulating valve 18 By controlling the first regulating valve 18 based on T 1 and T 2 , the steam temperatures T 1 and T 2 in the superheater tube 12 a of the second superheater 12 are lowered below the first threshold T 12.
  • the second regulating valve is based on the steam temperature (steam temperature at the inlet and outlet of the superheater tube 13a of the third superheating unit 13) T 3 and T 4 detected by the third temperature sensor 16c and the fourth temperature sensor 16d.
  • the steam temperatures T 3 and T 4 in the superheater tube 13 a of the third superheater 13 can be lowered below the second threshold value T 34. Therefore, high temperature corrosion of the superheater tube 12a of the second superheater portion 12 and the superheater tube 13a of the third superheater portion 13 can be suppressed. Further, in the present embodiment, since the second threshold value T 34 is set to a value larger than the first threshold value T 12, it is possible to control so that the steam temperature gradually rises.
  • the boiler system according to the present embodiment is a modification of the configuration of the temperature sensor and the control unit of the boiler system 1 according to the first embodiment, and other configurations are substantially the same as those of the first embodiment. Therefore, the configurations different from those of the first embodiment will be mainly described, and the common configurations will be designated by the same reference numerals and detailed description thereof will be omitted.
  • the superheater 10 of the boiler system has a first superheater portion 11, a second superheater portion 12, and a third superheater portion 13, and has a first superheater.
  • the unit 11, the second superheated unit 12, and the third superheated unit 13 each have superheater tubes 11a, 12a, and 13a for passing steam, and the first superheated unit 11 and the second superheated unit 12 are first connected. It is connected by a pipe 14, and the second superheated portion 12 and the third superheated portion 13 are connected by a second connecting pipe 15. Since these configurations are the same as those in the first embodiment, detailed description thereof will be omitted.
  • a first downstream temperature sensor 16 for detecting the steam temperature T 1A at the outlet of the superheater tube 12a of the second superheater 12 is provided on the downstream side of the second superheater 12. Further, on the downstream side of the third superheater portion 13, a second downstream temperature sensor 17 for detecting the steam temperature T 2A at the outlet of the superheater tube 13a is provided. Information about the steam temperature detected by the first downstream temperature sensor 16 and the second downstream temperature sensor 17 is sent to the control unit 30A described later and used for controlling various control valves.
  • the first downstream temperature sensor 16 and the second downstream temperature sensor 17 correspond to the temperature detection unit in the present invention.
  • the first connecting pipe 14 connecting the first superheated portion 11 and the second superheated portion 12 is connected to the pump 7 by the first water supply pipe 7a, and connects the second superheated portion 12 and the third superheated portion 13.
  • the two connecting pipes 15 are connected by a second water supply pipe 7b, and the first water supply pipe 7a connecting the pump 7 and the first connecting pipe 14 adjusts the flow rate of water flowing through the first water supply pipe 7a.
  • the first regulating valve 18 is provided, and the second water supply pipe 7b that connects the pump 7 and the second connecting pipe 15 is a second regulating valve that adjusts the flow rate of water flowing through the second water supply pipe 7b. 19 is provided.
  • the pump 7, the first and second water supply pipes 7a and 7b, the first and second connecting pipes 14 and 15 and the first and second regulating valves 18 and 19 are the same as those in the first embodiment. Omit.
  • the control unit 30A in the present embodiment controls the first regulating valve 18 and the second regulating valve 19 based on the steam temperatures T 1A and T 2A detected by the first downstream temperature sensor 16 and the second downstream temperature sensor 17. Thereby, the flow rate of the water supplied into the first connecting pipe 14 and the second connecting pipe 15 is controlled.
  • the control unit 30A the steam temperature T 1A detected by the first downstream temperature sensor 16 and the second downstream temperature sensor 17, the first and second T 2A each of the threshold T T1, T T2
  • the steam temperature in the first connecting pipe 14 and the second connecting pipe 15 is lowered, and as a result, the steam temperature T 1A and the third superheated portion at the outlet of the superheater pipe 12a of the second superheated portion 12
  • the first regulating valve 18 and the second regulating valve 19 are controlled so that the steam temperature T 2A at the outlet of the superheater tube 13a of 13 is lowered below the first and second thresholds TT 1 and TT 2, respectively.
  • the first and second thresholds T T1, T T2, similarly to the first embodiment is a value appropriately determined based on the deposition conditions of the ash or the like.
  • the pump 7, the first and second water supply pipes 7a and 7b (supply unit), the first adjusting valve 18, the second adjusting valve 19, and the control unit 30A in the present embodiment provide the first connecting pipe 14 and the first connection pipe.
  • a "steam temperature control unit" that lowers the temperature of the steam flowing through the first connecting pipe 14 and the second connecting pipe 15 below a predetermined temperature is configured. ..
  • a third downstream temperature sensor 50 for detecting the steam temperature T 3A at the outlet of the reheater tube 40a is provided.
  • the third downstream temperature sensor 50 also corresponds to the temperature detection unit in the present invention.
  • Information about the steam temperature detected by the third downstream temperature sensor 50 is sent to the control unit 30A and used for controlling the third regulating valve 60, which will be described later.
  • the pump 7 and the third water supply pipe 7c correspond to the supply unit in the present invention.
  • the third water supply pipe 7c is provided with a third adjustment valve 60 that adjusts the flow rate of water flowing through the third water supply pipe 7c, and the third adjustment valve 60 receives a control signal sent from the control unit 30A. By being controlled, it functions to adjust the amount of water supplied to the turbine bleeding pipe 100a (reheater pipe 40a).
  • the control unit 30A controls the third regulating valve 60 based on the steam temperature T 3A detected by the third downstream temperature sensor 50, so that the water supplied into the turbine bleeding pipe 100a (reheater pipe 40a) is supplied. Control the flow rate of. More specifically, the control unit 30 is inside the turbine bleeding pipe 100a (reheater pipe 40a) when the steam temperature T 3A detected by the third downstream temperature sensor 50 exceeds the third threshold T T 3.
  • the third regulating valve 60 is controlled so that the steam temperature T 3A at the outlet of the reheater tube 40a of the reheater 40 is lowered below the third threshold value T T 3.
  • the third threshold value T T3 is a value appropriately determined based on the adhesion state of ash and the like, similarly to the first and second threshold values T T1 and T T2.
  • Water is supplied to the inside of the turbine bleeding pipe 100a (reheater pipe 40a) by the pump 7, the third water supply pipe 7c (supply unit), the third regulating valve 60, and the control unit 30A in the present embodiment.
  • a "steam temperature control unit" that lowers the temperature of the steam flowing through the turbine bleeding pipe 100a (reheater pipe 40a) below a predetermined temperature is configured.
  • the control unit 30A of the boiler system detects the steam temperature T 1A at the outlet of the superheater tube 12a of the second superheater unit 12 by using the first downstream temperature sensor 16 (first temperature detection step: S1A).
  • the second downstream temperature sensor 17 is used to detect the steam temperature T 2A at the outlet of the superheater tube 13a of the third superheater 13 (second temperature detection step: S2A).
  • the control unit 30A detects the steam temperature T 3A at the outlet of the reheater tube 40a of the reheater 40 by using the third downstream temperature sensor 50 (third temperature detection step: S3A).
  • the control unit 30A of the boiler system controls the first regulating valve 18 when the steam temperature T 1A detected in the first temperature detection step S1A exceeds the first threshold value T T 1 , and controls the first connecting pipe. by controlling the flow rate of water supplied to the 14, to reduce the steam temperature in the first connecting pipe 14, as a result, the steam temperature T 1A at the outlet of the superheater tube 12a of the second heating unit 12 first It is lowered below one threshold T T1 (first steam temperature control step: S4A). Further, when the steam temperature T 2A detected in the second temperature detection step S2A exceeds the second threshold value T T2 , the control unit 30A controls the second regulating valve 19 and enters the second connecting pipe 15.
  • the control unit 30A controls the third regulating valve 60 to reheat the turbine bleed pipe 100a (reheat).
  • the steam temperature in the turbine bleeding pipe 100a reheater pipe 40a
  • the reheater pipe 40a of the reheater 40 is lowered.
  • the steam temperature T 3A at the outlet of is lowered below the threshold T T 3 (third steam temperature control step: S6A).
  • the boiler system according to the embodiment described above can also obtain the same effect as that of the first embodiment.
  • the second threshold value used for controlling the second regulating valve 19 arranged on the downstream side is used as the first threshold value used for controlling the first regulating valve 18 arranged on the upstream side.
  • the second threshold value can be set to the same value as the first threshold value.
  • the present invention is not limited to each of the above embodiments, and those having a design modification appropriately made by those skilled in the art are also included in the scope of the present invention as long as they have the features of the present invention.
  • each element included in each of the above embodiments its arrangement, material, condition, shape, size, and the like are not limited to those exemplified, and can be appropriately changed.
  • the elements included in each of the above embodiments can be combined as much as technically possible, and the combination thereof is also included in the scope of the present invention as long as the features of the present invention are included.
  • Boiler system 7 Pump (supply part, part of steam temperature control part) 7a ... First water supply pipe (supply part, part of steam temperature control part) 7b ... Second water supply pipe (supply part, part of steam temperature control part) 7c ... Third water supply pipe (supply part, part of steam temperature control part) 11 ... 1st superheater 11a ... Superheater pipe 12 ... 2nd superheater 12a ... Superheater pipe 13 ... 3rd superheater 13a ... Superheater pipe 14 ... 1st connection pipe 15 ... 2nd connection pipe 16 ... 1st downstream Temperature sensor (temperature detector) 16a ... First temperature sensor (temperature detector) 16b ...

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Abstract

The present invention efficiently lowers the surface temperature of pipes that make up a boiler system, thereby suppressing high-temperature corrosion of the pipes. A boiler system 1 comprises: a pipe (first connection pipe 14, second connection pipe 15, reheater pipe 40a) for circulating steam; and a steam temperature control unit (pump 7, pipes 7a, 7b, 7c, first regulating valve 18, second regulating valve 19, third regulating valve 60, control unit 30) that lowers the temperature (T1, T3, T5) of the steam circulating through the pipe below a predetermined temperature (T12, T34, T56) by supplying fluid to the interior of the pipe.

Description

ボイラシステム、制御方法及びプログラムBoiler system, control method and program
　本発明は、ボイラシステム、制御方法及びプログラムに関する。 The present invention relates to a boiler system, a control method and a program.
　従来より、燃料を燃焼炉で燃焼させることによって得られる高温の排ガスの熱により蒸気を生成するボイラシステムが種々提案されている。かかるボイラシステムには、蒸気ドラムで発生した蒸気を更に高温・高圧に過熱する過熱器が設けられている。過熱器で過熱された蒸気は、蒸気タービンに供給されて発電機の駆動等に使用される。 Conventionally, various boiler systems have been proposed in which steam is generated by the heat of high-temperature exhaust gas obtained by burning fuel in a combustion furnace. Such a boiler system is provided with a superheater that heats the steam generated by the steam drum to a higher temperature and higher pressure. The steam superheated by the superheater is supplied to the steam turbine and used for driving a generator or the like.
　現在、火力発電所の熱サイクル（ランキンサイクル）から取り出すエネルギを最大化するために、ボイラ出口の蒸気の温度（最下流の過熱器から排出される蒸気の温度：以下「主蒸気温度」と称する）を上昇させる手法が採用されている。しかし、主蒸気温度を上昇させると、過熱器を構成する過熱器管内を高温の蒸気が流通することとなり、その結果、過熱器管の表面温度も高温となる。そうすると、排ガスに含まれる塩化物や硫化物等からなる灰が溶融して過熱器管の表面に付着し、過熱器管の高温腐食を促進してしまう虞がある。 Currently, in order to maximize the energy extracted from the thermal cycle (Rankine cycle) of a thermal power plant, the temperature of the steam at the outlet of the boiler (the temperature of the steam discharged from the most downstream superheater: hereinafter referred to as the "main steam temperature". ) Is raised. However, when the main steam temperature is raised, high-temperature steam flows through the superheater tube constituting the superheater, and as a result, the surface temperature of the superheater tube also becomes high. Then, the ash composed of chlorides and sulfides contained in the exhaust gas may be melted and adhered to the surface of the superheater tube to promote high temperature corrosion of the superheater tube.
　このため、近年、過熱器近傍に腐食検知器を設けておき、腐食信号が所定の閾値を超えた場合に、燃焼炉の運転を制御して排ガスの温度を低下させる技術が提案されている（例えば、特許文献１参照）。かかる技術を採用すると、過熱器管の表面に溶融灰が付着することを抑制することができ、腐食環境を軽減することができる、とされている。 For this reason, in recent years, a technique has been proposed in which a corrosion detector is provided near the superheater to control the operation of the combustion furnace to lower the temperature of the exhaust gas when the corrosion signal exceeds a predetermined threshold value. For example, see Patent Document 1). It is said that by adopting such a technique, it is possible to suppress the adhesion of molten ash to the surface of the superheater tube and reduce the corrosive environment.
特開２００２－１０６８２２号公報JP-A-2002-106822
　特許文献１に記載されたような従来の技術は、排ガスの温度を低下させることにより過熱器管の表面温度を低下させるものであるが、過熱器（特に最下流に配置される過熱器）を構成する過熱器管の内部にはきわめて高温（例えば５４１℃）の蒸気が流通するため、排ガスの温度を低下させるだけでは過熱器管の表面温度を効率良く低下させることできなかった。 The conventional technique as described in Patent Document 1 lowers the surface temperature of the superheater tube by lowering the temperature of the exhaust gas, but a superheater (particularly a superheater arranged at the most downstream side) is used. Since extremely high temperature (for example, 541 ° C.) steam flows inside the constituent superheater tubes, it was not possible to efficiently reduce the surface temperature of the superheater tube simply by lowering the temperature of the exhaust gas.
　本発明は、かかる事情に鑑みてなされたものであり、ボイラシステムを構成する管の表面温度を効率良く低下させることにより、管の高温腐食を抑制することを目的とする。 The present invention has been made in view of such circumstances, and an object of the present invention is to suppress high-temperature corrosion of pipes by efficiently lowering the surface temperature of the pipes constituting the boiler system.
　前記目的を達成するため、本発明に係るボイラシステムは、蒸気を流通させる管と、管の内部に流体を供給することにより、管を流通する蒸気の温度を所定温度よりも低下させる蒸気温度制御部と、を備えるものである。 In order to achieve the above object, the boiler system according to the present invention has a pipe through which steam flows and a steam temperature control in which the temperature of the steam flowing through the pipe is lowered below a predetermined temperature by supplying a fluid inside the pipe. It is equipped with a part.
　また、本発明に係る制御方法は、蒸気を流通させる管を備えるボイラシステムの蒸気温度を制御する方法であって、管の内部に流体を供給することにより、管を流通する蒸気の温度を所定温度よりも低下させる蒸気温度制御工程を含むものである。 Further, the control method according to the present invention is a method of controlling the steam temperature of a boiler system including a pipe through which steam flows, and a temperature of steam flowing through the pipe is determined by supplying a fluid inside the pipe. It includes a steam temperature control step that lowers the temperature below the temperature.
　また、本発明に係るプログラムは、蒸気を流通させる管を備えるボイラシステムの蒸気温度を制御する方法をコンピュータに実行させるプログラムであって、当該方法は、管の内部に流体を供給することにより、管を流通する蒸気の温度を所定温度よりも低下させる蒸気温度制御工程を含むものである。 Further, the program according to the present invention is a program for causing a computer to execute a method of controlling the steam temperature of a boiler system including a pipe for circulating steam, and the method is a program in which a fluid is supplied to the inside of the pipe. It includes a steam temperature control step of lowering the temperature of steam flowing through the pipe below a predetermined temperature.
　かかる構成及び方法を採用すると、管の内部に流体を供給することにより、管を流通する蒸気温度を所定温度よりも低下させることができるので、排ガスの温度を低下させる従来の手法よりも管の表面温度を効率良く低下させることができる。従って、管の表面に溶融灰が付着することを抑制して、管の高温腐食を抑制することができる。 By adopting such a configuration and method, the temperature of the steam flowing through the pipe can be lowered below a predetermined temperature by supplying the fluid to the inside of the pipe, so that the temperature of the exhaust gas can be lowered more than the conventional method of lowering the temperature of the pipe. The surface temperature can be lowered efficiently. Therefore, it is possible to suppress the adhesion of molten ash to the surface of the pipe and suppress the high temperature corrosion of the pipe.
　本発明に係るボイラシステムにおいて、蒸気温度を検出する温度検出部を備えることができる。かかる場合において、蒸気温度制御部は、管内に流体を供給する供給部と、供給部による流体の供給量を調整する調整弁と、温度検出部で検出された蒸気温度に基づいて調整弁を制御することにより管内に供給される流体の流量を制御する制御部と、を有することができる。 The boiler system according to the present invention can be provided with a temperature detection unit that detects the steam temperature. In such a case, the steam temperature control unit controls the supply unit that supplies the fluid into the pipe, the adjustment valve that adjusts the amount of fluid supplied by the supply unit, and the adjustment valve based on the steam temperature detected by the temperature detection unit. By doing so, it is possible to have a control unit that controls the flow rate of the fluid supplied into the pipe.
　かかる構成を採用すると、温度検出部で検出された蒸気温度に基づいて調整弁を制御することにより、管内に供給される流体の流量を制御部で制御することができる。従って、蒸気温度に応じて適切な制御を行うことができる。 If such a configuration is adopted, the flow rate of the fluid supplied into the pipe can be controlled by the control unit by controlling the regulating valve based on the steam temperature detected by the temperature detection unit. Therefore, appropriate control can be performed according to the steam temperature.
　本発明に係るボイラシステムにおいて、制御部は、温度検出部で検出された蒸気温度が所定の閾値を超えた場合に、管内の蒸気温度を当該閾値よりも低下させるように調整弁を制御することができる。ここで、閾値は、管への灰の付着状態や灰の燃料性状に応じて設定することができる。 In the boiler system according to the present invention, the control unit controls the regulating valve so that when the steam temperature detected by the temperature detection unit exceeds a predetermined threshold value, the steam temperature in the pipe is lowered below the threshold value. Can be done. Here, the threshold value can be set according to the state of ash adhering to the pipe and the fuel properties of the ash.
　かかる構成を採用すると、温度検出部で検出された蒸気温度が所定の閾値を超えた場合に、管内の蒸気温度を当該閾値よりも低下させるように制御部で調整弁を制御することができる。 By adopting such a configuration, when the steam temperature detected by the temperature detection unit exceeds a predetermined threshold value, the control unit can control the regulating valve so that the steam temperature in the pipe is lowered below the threshold value.
　本発明に係るボイラシステムにおいて、第一過熱部と、第一過熱部よりも下流側にある第二過熱部と、第二過熱部よりも下流側になる第三過熱部と、を有する過熱器を備えることができる。かかる場合において、管は、第一過熱部の過熱器管と第二過熱部の過熱器管とを接続する第一接続管と、第二過熱部の過熱器管と第三過熱部の過熱器管とを接続する第二接続管と、を含むことができる。また、温度検出部は、第二過熱部の過熱器管の入口における蒸気温度を検出する第一温度センサと、第二過熱部の過熱器管の出口における蒸気温度を検出する第二温度センサと、第三過熱部の過熱器管の入口における蒸気温度を検出する第三温度センサと、第三過熱部の過熱器管の出口における蒸気温度を検出する第四温度センサと、を含むことができ、供給部は、流体を供給するポンプと、ポンプと第一接続管とを接続する第一給水配管と、ポンプと第二接続管とを接続する第二給水配管と、を含むことができ、調整弁は、第一接続管に供給される流体の供給量を調整する第一調整弁と、第二接続管に供給される流体の供給量を調整する第二調整弁と、を含むことができる。そして、制御部は、第一温度センサ及び第二温度センサで検出された蒸気温度に基づいて第一調整弁を制御することにより、第二過熱部の過熱器管内の蒸気温度を第一の閾値よりも低下させるとともに、第三温度センサ及び第四温度センサで検出された蒸気温度に基づいて第二調整弁を制御することにより、第三過熱部の過熱器管内の蒸気温度を第二の閾値よりも低下させることができる。この際、第二の閾値を、第一の閾値よりも大きい値に設定することができる。 In the boiler system according to the present invention, a superheater having a first superheater, a second superheater downstream of the first superheater, and a third superheater downstream of the second superheater. Can be provided. In such a case, the pipes are the first connection pipe connecting the superheater pipe of the first superheater part and the superheater pipe of the second superheater part, and the superheater pipe of the second superheater part and the superheater of the third superheater part. It can include a second connecting pipe that connects to the pipe. Further, the temperature detection unit includes a first temperature sensor that detects the steam temperature at the inlet of the superheater tube of the second superheater, and a second temperature sensor that detects the steam temperature at the outlet of the superheater tube of the second superheater. , A third temperature sensor that detects the steam temperature at the inlet of the superheater tube of the third superheater, and a fourth temperature sensor that detects the steam temperature at the outlet of the superheater tube of the third superheater can be included. The supply unit can include a pump that supplies fluid, a first water supply pipe that connects the pump and the first connecting pipe, and a second water supply pipe that connects the pump and the second connecting pipe. The regulating valve may include a first regulating valve that regulates the supply amount of fluid supplied to the first connecting pipe and a second regulating valve that regulates the supply amount of fluid supplied to the second connecting pipe. it can. Then, the control unit controls the first regulating valve based on the steam temperature detected by the first temperature sensor and the second temperature sensor, thereby setting the steam temperature in the superheater tube of the second superheating unit as the first threshold value. By controlling the second regulating valve based on the steam temperature detected by the third temperature sensor and the fourth temperature sensor, the steam temperature in the superheater tube of the third superheater is set to the second threshold value. Can be lowered than. At this time, the second threshold value can be set to a value larger than the first threshold value.
　かかる構成を採用すると、第一温度センサ及び第二温度センサで検出された蒸気温度（第二過熱部の過熱器管の入口及び出口の蒸気温度）に基づいて第一調整弁を制御することにより、第二過熱部の過熱器管内の蒸気温度を第一の閾値よりも低下させるとともに、第三温度センサ及び第四温度センサで検出された蒸気温度（第三過熱部の過熱器管の入口及び出口における蒸気温度）に基づいて第二調整弁を制御することにより、第三過熱部の過熱器管内の蒸気温度を第二の閾値よりも低下させることができる。従って、第二過熱部及び第三過熱部の過熱器管の高温腐食を抑制することができる。この際、第二の閾値を第一の閾値よりも大きい値に設定しているため、蒸気温度が徐々に上昇するように制御することが可能となる。 When such a configuration is adopted, the first regulating valve is controlled based on the steam temperature (steam temperature at the inlet and outlet of the superheater tube of the second superheater) detected by the first temperature sensor and the second temperature sensor. , The steam temperature in the superheater tube of the second superheater is lowered below the first threshold, and the steam temperature detected by the third temperature sensor and the fourth temperature sensor (the inlet of the superheater tube of the third superheater and By controlling the second regulating valve based on the steam temperature at the outlet), the steam temperature in the superheater tube of the third superheater can be lowered below the second threshold. Therefore, high temperature corrosion of the superheater tubes of the second superheated portion and the third superheated portion can be suppressed. At this time, since the second threshold value is set to a value larger than the first threshold value, it is possible to control so that the steam temperature gradually rises.
　本発明に係るボイラシステムにおいて、タービンから排出された蒸気を再加熱する再熱器を備えることができる。かかる場合において、管は、タービンと再熱器の再熱器管とを接続するタービン抽気配管を含むことができる。また、温度検出部は、再熱器の再熱器管の入口における蒸気温度を検出する入口温度センサと、再熱器の再熱器管の出口における蒸気温度を検出する出口温度センサと、を含むことができ、供給部は、流体を供給するポンプと、ポンプとタービン抽気配管とを接続する第三給水配管と、を含むことができ、調整弁は、タービン抽気配管に供給される流体の供給量を調整する第三調整弁を含むことができる。そして、制御部は、入口温度センサ及び出口温度センサで検出された蒸気温度に基づいて第三調整弁を制御することにより、再熱器の再熱器管内の蒸気温度を第三の閾値よりも低下させることができる。 The boiler system according to the present invention can be provided with a reheater that reheats the steam discharged from the turbine. In such cases, the pipe may include a turbine bleed pipe connecting the turbine and the reheater pipe of the reheater. Further, the temperature detection unit includes an inlet temperature sensor that detects the steam temperature at the inlet of the reheater tube of the reheater and an outlet temperature sensor that detects the steam temperature at the outlet of the reheater tube of the reheater. The supply unit can include a pump that supplies the fluid and a third water supply pipe that connects the pump to the turbine bleed pipe, and the regulating valve is for the fluid supplied to the turbine bleed pipe. A third regulating valve that regulates the supply amount can be included. Then, the control unit controls the third regulating valve based on the steam temperature detected by the inlet temperature sensor and the outlet temperature sensor, so that the steam temperature in the reheater tube of the reheater is set to be higher than the third threshold value. Can be lowered.
　かかる構成を採用すると、入口温度センサ及び出口温度センサで検出された蒸気温度（再熱器の再熱器管の入口及び出口における蒸気温度）に基づいて第三調整弁を制御することにより、再熱器の再熱器管内の蒸気温度を第三の閾値よりも低下させることができる。従って、再熱器の再熱器管の高温腐食を抑制することができる。 When such a configuration is adopted, the third regulating valve is re-controlled based on the steam temperature (steam temperature at the inlet and outlet of the reheater tube of the reheater) detected by the inlet temperature sensor and the outlet temperature sensor. The steam temperature in the reheater tube of the heater can be lowered below the third threshold. Therefore, high temperature corrosion of the reheater tube of the reheater can be suppressed.
　本発明によれば、ボイラシステムを構成する管の表面温度を効率良く低下させることにより、管の高温腐食を抑制することが可能となる。 According to the present invention, it is possible to suppress high temperature corrosion of the pipe by efficiently lowering the surface temperature of the pipe constituting the boiler system.
本発明の第一実施形態に係るボイラシステムの全体構成を示す概略図である。It is the schematic which shows the whole structure of the boiler system which concerns on 1st Embodiment of this invention. 本発明の第一実施形態に係るボイラシステムの過熱器周辺の構成を示す図である。It is a figure which shows the structure around the superheater of the boiler system which concerns on 1st Embodiment of this invention. 本発明の第一実施形態に係るボイラシステムの蒸気温度を制御する方法を説明するためのフローチャートである。It is a flowchart for demonstrating the method of controlling the steam temperature of the boiler system which concerns on 1st Embodiment of this invention. 本発明の第一実施形態に係るボイラシステムの蒸気温度の変化の一例を示すグラフである。It is a graph which shows an example of the change of the steam temperature of the boiler system which concerns on 1st Embodiment of this invention. 本発明の第二実施形態に係るボイラシステムの過熱器周辺の構成を示す図である。It is a figure which shows the structure around the superheater of the boiler system which concerns on the 2nd Embodiment of this invention. 本発明の第二実施形態に係るボイラシステムの蒸気温度を制御する方法を説明するためのフローチャートである。It is a flowchart for demonstrating the method of controlling the steam temperature of the boiler system which concerns on 2nd Embodiment of this invention.
　以下、図面を参照して、本発明の各実施形態について説明する。なお、以下の各実施形態はあくまでも好適な適用例であって、本発明の適用範囲がこれに限定されるものではない。 Hereinafter, each embodiment of the present invention will be described with reference to the drawings. It should be noted that the following embodiments are merely suitable application examples, and the scope of application of the present invention is not limited thereto.
＜第一実施形態＞
　まず、図１～図４を用いて、本発明の第一実施形態に係るボイラシステム１について説明する。本実施形態に係るボイラシステム１は、循環流動層ボイラ（Circulating Fluidized Bed型）システムであって、高温で流動する循環材（珪砂等）を循環させながら燃料を燃焼して、蒸気を発生させるものである。ボイラシステム１の燃料としては、例えば非化石燃料（木質バイオマス、廃タイヤ、廃プラスチック、スラッジ等）を使用することができる。ボイラシステム１で発生した蒸気は、後述するタービン１００、１０１の駆動に用いられる。 <First Embodiment>
First, the boiler system 1 according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 4. The boiler system 1 according to the present embodiment is a circulating fluidized bed type system that burns fuel while circulating a circulating material (silica sand or the like) that flows at a high temperature to generate steam. Is. As the fuel for the boiler system 1, for example, non-fossil fuel (woody biomass, waste tires, waste plastic, sludge, etc.) can be used. The steam generated in the boiler system 1 is used to drive the turbines 100 and 101, which will be described later.
　ボイラシステム１は、火炉２内で燃料を燃焼させ、固気分離装置として機能するサイクロン３によって排ガスから循環材を分離し、分離された循環材を火炉２内に戻して循環させるように構成されている。分離された循環材は、サイクロン３の下方に接続された循環材回収管４を経由して火炉２の下部に返送される。なお、循環材回収管４の下部と火炉２の下部とは、図１に示すように流路が絞られたループシール部４ａを介して接続されている。これにより、循環材回収管４の下部には所定量の循環材が貯められた状態となる。サイクロン３によって循環材が取り除かれた排ガスは、排ガス流路３ａを経由して後部煙道５に供給される。 The boiler system 1 is configured to burn fuel in the fireplace 2, separate the circulating material from the exhaust gas by a cyclone 3 functioning as a solid air separating device, and return the separated circulating material to the furnace 2 for circulation. ing. The separated circulating material is returned to the lower part of the fireplace 2 via the circulating material recovery pipe 4 connected below the cyclone 3. The lower part of the circulation material recovery pipe 4 and the lower part of the fireplace 2 are connected to each other via a loop seal portion 4a having a narrowed flow path as shown in FIG. As a result, a predetermined amount of circulating material is stored in the lower part of the circulating material recovery pipe 4. The exhaust gas from which the circulating material has been removed by the cyclone 3 is supplied to the rear flue 5 via the exhaust gas flow path 3a.
　火炉２は、燃料を燃焼させる燃焼炉である。火炉２の中間部には、燃料を供給する燃料供給口２ａが設けられており、火炉２の上部には、燃焼ガスを排出するガス出口２ｂが設けられている。図示されていない燃料供給装置から火炉２に供給される燃料は、燃料供給口２ａを介して火炉２の内部に供給される。また、火炉２の炉壁には、ボイラ給水を加熱するための炉壁管６が設けられている。炉壁管６を流れるボイラ給水は、火炉２での燃焼によって加熱される。 The fireplace 2 is a combustion furnace that burns fuel. A fuel supply port 2a for supplying fuel is provided in the middle portion of the fireplace 2, and a gas outlet 2b for discharging combustion gas is provided in the upper portion of the fireplace 2. The fuel supplied to the fireplace 2 from the fuel supply device (not shown) is supplied to the inside of the fireplace 2 via the fuel supply port 2a. Further, a furnace wall pipe 6 for heating the boiler water supply is provided on the furnace wall of the fireplace 2. The boiler water supply flowing through the furnace wall pipe 6 is heated by combustion in the furnace 2.
　火炉２内では、下部の給気ライン２ｃから導入される燃焼・流動用の空気により、燃料供給口２ａから供給された燃料を含む固形物が流動し、燃料は流動しながら例えば約８００～９００℃ で燃焼する。サイクロン３には、火炉２で発生した燃焼ガスが循環材を同伴しながら導入される。サイクロン３は、遠心分離作用により循環材と気体とを分離し、循環材回収管４を介して分離された循環材を火炉２に戻すと共に、循環材が除かれた燃焼ガスを排ガス流路３ａから後述する後部煙道５へと送出する。 In the furnace 2, the combustion / flow air introduced from the lower air supply line 2c causes the solid matter including the fuel supplied from the fuel supply port 2a to flow, and the fuel flows while flowing, for example, about 800 to 900. Burns at ℃. The combustion gas generated in the fireplace 2 is introduced into the cyclone 3 with a circulating material. The cyclone 3 separates the circulating material and the gas by a centrifugal separation action, returns the circulating material separated through the circulating material recovery pipe 4 to the fireplace 2, and returns the combustion gas from which the circulating material has been removed to the exhaust gas flow path 3a. Is sent to the rear flue 5, which will be described later.
　火炉２では、炉内ベッド材と呼ばれる固形物が発生し底部に溜まるが、この炉内ベッド材で不純物（低融点物質等）が濃縮されて起こるベッド材の焼結及び溶融固化、或いは不燃夾雑物による動作不良を抑制することが必要である。このため、火炉２では、底部の排出口２ｄから炉内ベッド材が連続的又は断続的に外部に排出されている。排出されたベッド材は、図示されていない循環ライン上で金属や粗大粒径等の不適物を取り除いた後、再び火炉２に供給されるか、若しくはそのまま廃棄される。火炉２の循環材は、火炉２、サイクロン３及び循環材回収管４で構成される循環系内を循環する。 In the furnace 2, solid substances called in-core bed materials are generated and accumulated at the bottom, and impurities (low melting point substances, etc.) are concentrated in the in-core bed material to cause sintering and melt solidification of the bed material, or non-combustible contamination. It is necessary to suppress malfunctions caused by objects. Therefore, in the fireplace 2, the bed material in the furnace is continuously or intermittently discharged to the outside from the discharge port 2d at the bottom. The discharged bed material is supplied to the fireplace 2 again after removing unsuitable substances such as metal and coarse particle size on a circulation line (not shown), or is discarded as it is. The circulation material of the fireplace 2 circulates in the circulation system composed of the fireplace 2, the cyclone 3, and the circulation material recovery pipe 4.
　後部煙道５は、サイクロン３から排出されたガスを後段へ流す流路を有している。後部煙道５は、排ガスの熱を回収する排熱回収部として、過熱蒸気を発生させる過熱器１０と、ボイラ給水を予熱する節炭器２０と、を有している。後部煙道５を流れる排ガスは、過熱器１０及び節炭器２０を流通する蒸気やボイラ給水と熱交換されて冷却される。また、後部煙道５は、ボイラ給水を節炭器２０に供給するポンプ７と、節炭器２０を通過したボイラ給水が貯留されるとともに、火炉２の炉壁管６に接続された蒸気ドラム８と、を有している。過熱器１０の構成については、後に詳述する。 The rear flue 5 has a flow path for flowing the gas discharged from the cyclone 3 to the rear stage. The rear flue 5 has a superheater 10 for generating superheated steam and an economizer 20 for preheating the boiler water supply as an exhaust heat recovery unit for recovering the heat of the exhaust gas. The exhaust gas flowing through the rear flue 5 is cooled by exchanging heat with steam and boiler water supply flowing through the superheater 10 and the economizer 20. Further, the rear flue 5 stores the pump 7 that supplies the boiler water supply to the economizer 20 and the boiler water supply that has passed through the economizer 20, and the steam drum connected to the furnace wall pipe 6 of the fireplace 2. It has 8 and. The configuration of the superheater 10 will be described in detail later.
　節炭器２０は、排ガスの熱をボイラ給水に伝熱して、ボイラ給水を予熱するものである。節炭器２０は、配管２１によってポンプ７と接続される一方、配管２２によって蒸気ドラム８と接続されている。ポンプ７から配管２１を経由して節炭器２０に供給され、節炭器２０によって予熱されたボイラ給水は、配管２２を経由して蒸気ドラム８に供給される。 The economizer 20 transfers the heat of the exhaust gas to the boiler water supply to preheat the boiler water supply. The economizer 20 is connected to the pump 7 by a pipe 21 while being connected to the steam drum 8 by a pipe 22. The boiler water supplied from the pump 7 to the economizer 20 via the pipe 21 and preheated by the economizer 20 is supplied to the steam drum 8 via the pipe 22.
　蒸気ドラム８には、降水管８ａ及び炉壁管６が接続されている。蒸気ドラム８内のボイラ給水は、降水管８ａを下降し、火炉２の下部側で炉壁管６に導入されて蒸気ドラム８へ向かって流通する。炉壁管６内のボイラ給水は、火炉２内で発生する燃焼熱によって加熱されて、蒸気ドラム８内で蒸発し蒸気となる。 A precipitation pipe 8a and a furnace wall pipe 6 are connected to the steam drum 8. The boiler water supply in the steam drum 8 descends from the precipitation pipe 8a, is introduced into the furnace wall pipe 6 on the lower side of the furnace 2, and flows toward the steam drum 8. The boiler water supply in the furnace wall pipe 6 is heated by the combustion heat generated in the furnace 2 and evaporates in the steam drum 8 to become steam.
　蒸気ドラム８には、内部の蒸気を排出する排気管８ｂが接続されている。排気管８ｂは、蒸気ドラム８と過熱器１０とを接続している。蒸気ドラム８内の蒸気は、排気管８ｂを経由して過熱器１０に供給される。過熱器１０は、排ガスの熱を用いて蒸気を過熱して過熱蒸気を生成するものである。過熱蒸気は、配管１０ａを通り、ボイラシステム１外のタービン１００、１０１に供給されて発電に利用される。 An exhaust pipe 8b for discharging internal steam is connected to the steam drum 8. The exhaust pipe 8b connects the steam drum 8 and the superheater 10. The steam in the steam drum 8 is supplied to the superheater 10 via the exhaust pipe 8b. The superheater 10 uses the heat of exhaust gas to superheat steam to generate superheated steam. The superheated steam passes through the pipe 10a and is supplied to the turbines 100 and 101 outside the boiler system 1 to be used for power generation.
　ここで、図２を用いて、本実施形態に係るボイラシステム１の過熱器１０周辺の構成について具体的に説明する。 Here, with reference to FIG. 2, the configuration around the superheater 10 of the boiler system 1 according to the present embodiment will be specifically described.
　過熱器１０は、図２に示すように、排気管８ｂから導入された蒸気を過熱する第一過熱部１１と、第一過熱部１１から導入された蒸気をさらに過熱する第二過熱部１２と、第二過熱部１２から導入された蒸気をさらに過熱する第三過熱部１３と、を有している。第一過熱部１１、第二過熱部１２及び第三過熱部１３は各々、蒸気を流通させる過熱器管１１ａ、１２ａ、１３ａを有している。また、第一過熱部１１と第二過熱部１２は第一接続管１４で接続され、第二過熱部１２と第三過熱部１３は第二接続管１５で接続されている。 As shown in FIG. 2, the superheater 10 includes a first superheater section 11 that superheats the steam introduced from the exhaust pipe 8b, and a second superheater section 12 that further superheats the steam introduced from the first superheater section 11. , A third superheater 13 that further superheats the steam introduced from the second superheater 12. The first superheater section 11, the second superheater section 12, and the third superheater section 13 each have superheater tubes 11a, 12a, and 13a for passing steam. Further, the first superheated portion 11 and the second superheated portion 12 are connected by a first connecting pipe 14, and the second superheated portion 12 and the third superheated portion 13 are connected by a second connecting pipe 15.
　第二過熱部１２の上流側には、過熱器管１２ａの入口における蒸気温度Ｔ１を検出する第一温度センサ１６ａが設けられており、第二過熱部１２の下流側には、第二過熱部１２の過熱器管１２ａの出口における蒸気温度Ｔ２を検出する第二温度センサ１６ｂが設けられている。また、第三過熱部１３の上流側には、過熱器管１３ａの入口における蒸気温度Ｔ３を検出する第三温度センサ１６ｃが設けられており、第三過熱部１３の下流側には、過熱器管１３ａの出口における蒸気温度Ｔ４を検出する第四温度センサ１６ｄが設けられている。第一温度センサ１６ａ、第二温度センサ１６ｂ、第三温度センサ１６ｃ及び第四温度センサ１６ｄで検出された蒸気温度に関する情報は、後述する制御部３０に送られて各種調整弁の制御に用いられる。第一温度センサ１６ａ、第二温度センサ１６ｂ、第三温度センサ１６ｃ及び第四温度センサ１６ｄは、本発明における温度検出部に対応するものである。 On the upstream side of the second heating unit 12, and the first temperature sensor 16a is provided for detecting the steam temperature T 1 of at the inlet of the superheater tubes 12a, on the downstream side of the second heating unit 12, the second overheat A second temperature sensor 16b for detecting the steam temperature T 2 at the outlet of the superheater tube 12a of the unit 12 is provided. Further, on the upstream side of the third superheated portion 13 has a third temperature sensor 16c is provided for detecting the steam temperature T 3 at the inlet of the superheater tubes 13a, on the downstream side of the third superheated portion 13, superheated fourth temperature sensor 16d for detecting the steam temperature T 4 at the outlet of the organ 13a. Information on the steam temperature detected by the first temperature sensor 16a, the second temperature sensor 16b, the third temperature sensor 16c, and the fourth temperature sensor 16d is sent to the control unit 30 described later and used to control various control valves. .. The first temperature sensor 16a, the second temperature sensor 16b, the third temperature sensor 16c, and the fourth temperature sensor 16d correspond to the temperature detection unit in the present invention.
　第一過熱部１１と第二過熱部１２とを接続する第一接続管１４は、第一給水配管７ａによってポンプ７と接続され、第二過熱部１２と第三過熱部１３とを接続する第二接続管１５は、第二給水配管７ｂによって接続されている。そして、蒸気冷却用の水が、ポンプ７から第一給水配管７ａを経由して第一接続管１４に供給され、ポンプ７から第二給水配管７ｂを経由して第二接続管１５に供給される。なお、第一給水配管７ａ及び第二給水配管７ｂは、上流側（ポンプ７側）の配管部分７ａｂが共通している。ポンプ７及び第一・第二給水配管７ａ、７ｂは、本発明における供給部に対応するものである。 The first connection pipe 14 that connects the first superheated portion 11 and the second superheated portion 12 is connected to the pump 7 by the first water supply pipe 7a, and connects the second superheated portion 12 and the third superheated portion 13. The two connecting pipes 15 are connected by a second water supply pipe 7b. Then, water for steam cooling is supplied from the pump 7 to the first connecting pipe 14 via the first water supply pipe 7a, and is supplied from the pump 7 to the second connecting pipe 15 via the second water supply pipe 7b. To. The first water supply pipe 7a and the second water supply pipe 7b have a common pipe portion 7ab on the upstream side (pump 7 side). The pump 7 and the first and second water supply pipes 7a and 7b correspond to the supply unit in the present invention.
　ポンプ７と第一接続管１４とを接続する第一給水配管７ａには、第一給水配管７ａ内を流通する水の流量を調整する第一調整弁１８が設けられており、ポンプ７と第二接続管１５とを接続する第二給水配管７ｂには、第二給水配管７ｂ内を流通する水の流量を調整する第二調整弁１９が設けられている。第一調整弁１８及び第二調整弁１９は、後述する制御部３０から送られる制御信号によって制御されることにより、第一接続管１４及び第二接続管１５への水の供給量を調整するように機能する。 The first water supply pipe 7a connecting the pump 7 and the first connection pipe 14 is provided with a first adjustment valve 18 for adjusting the flow rate of water flowing through the first water supply pipe 7a, and the pump 7 and the first water supply pipe 14 are provided. The second water supply pipe 7b that connects the two connection pipes 15 is provided with a second adjustment valve 19 that adjusts the flow rate of water flowing through the second water supply pipe 7b. The first regulating valve 18 and the second regulating valve 19 adjust the amount of water supplied to the first connecting pipe 14 and the second connecting pipe 15 by being controlled by a control signal sent from the control unit 30 described later. Works like.
　本実施形態に係るボイラシステム１は、システムに設けられた各種構成を統合制御する制御部３０を備えている。制御部３０は、各種制御プログラムや各種制御用データ等を格納するメモリや、各種制御プログラムを実行するプロセッサ等によって構成されている。 The boiler system 1 according to the present embodiment includes a control unit 30 that integrally controls various configurations provided in the system. The control unit 30 is composed of a memory for storing various control programs, various control data, and the like, a processor for executing various control programs, and the like.
　制御部３０は、第一温度センサ１６ａ、第二温度センサ１６ｂ、第三温度センサ１６ｃ及び第四温度センサ１６ｄで検出された蒸気温度Ｔ１、Ｔ２、Ｔ３、Ｔ４に基づいて第一調整弁１８及び第二調整弁１９を制御することにより、第一接続管１４及び第二接続管１５内に供給される水の流量を制御する。さらに具体的には、制御部３０は、第一温度センサ１６ａ及び第二温度センサ１６ｂで検出された蒸気温度Ｔ１、Ｔ２（第二過熱部１２の過熱器管１２ａの入口及び出口における蒸気温度）の平均値と、第三温度センサ１６ｃ及び第四温度センサ１６ｄで検出された蒸気温度Ｔ３、Ｔ４（第三過熱部１３の過熱器管１３ａの入口及び出口における蒸気温度）の平均値と、が各々第一及び第二の閾値Ｔ１２、Ｔ３４を超えた場合に、第一接続管１４内及び第二接続管１５内の蒸気温度を低下させ、その結果、第二過熱部１２の過熱器管１２ａの入口における蒸気温度（第一接続管１４内の蒸気温度）Ｔ１及び第三過熱部１３の過熱器管１３ａの入口における蒸気温度（第二接続管１５内の蒸気温度）Ｔ３を第一及び第二の閾値Ｔ１２、Ｔ３４よりも各々低下させるように第一調整弁１８及び第二調整弁１９を制御する。 The control unit 30 first is based on the steam temperatures T 1 , T 2 , T 3 , and T 4 detected by the first temperature sensor 16a, the second temperature sensor 16b, the third temperature sensor 16c, and the fourth temperature sensor 16d. By controlling the regulating valve 18 and the second regulating valve 19, the flow rate of water supplied into the first connecting pipe 14 and the second connecting pipe 15 is controlled. More specifically, the control unit 30 has steam temperatures T 1 and T 2 (steam at the inlet and outlet of the superheater tube 12a of the second superheater 12) detected by the first temperature sensor 16a and the second temperature sensor 16b. Average value of temperature) and steam temperatures T 3 and T 4 (steam temperature at the inlet and outlet of the superheater tube 13a of the third superheater 13) detected by the third temperature sensor 16c and the fourth temperature sensor 16d). When the values and the values exceed the first and second thresholds T 12 and T 34 , respectively, the steam temperature in the first connecting pipe 14 and the second connecting pipe 15 is lowered, and as a result, the second overheating part steam temperature at the inlet of the superheater tubes 12a of 12 steam temperature (first steam temperature of the connecting pipe 14) T 1 and the steam temperature at the inlet of the superheater tubes 13a of the third superheated portion 13 (the second connecting pipe 15 ) The first regulating valve 18 and the second regulating valve 19 are controlled so that T 3 is lower than the first and second thresholds T 12 and T 34, respectively.
　ここで、第一及び第二の閾値Ｔ１２、Ｔ３４は、灰の付着状況、燃料や燃焼灰の成分分析値、定期検査時の灰の管への付着状況、管の腐食状況、等に基づいて適宜決定される値であり、例えば、排ガスに含まれる灰の融点、ボイラシステム１に接続されるタービン１００、１０１側の要求によって設定される特定の温度、等を所定の閾値として採用することができる。燃料には、塩素のほかアルカリ金属類（ナトリウムやカリウム等）が含まれることがあり、塩素、ナトリウム、カリウム等で生成される塩化物や硫化物は、火炉２内の燃焼場温度（約８７０℃）よりも低い融点を有することがある。低融点物質としては、例えば塩化ナトリウム、塩化カルシウム、塩化カリウム、硫酸ナトリウム、硫酸カリウム、ピロ硫酸カリウム、ナトリウム又はカリウムの三硫化物（Na3Fe(SO4)3、K3Fe(SO4)3）、等が挙げられる。第一及び第二の閾値Ｔ１２、Ｔ３４は、これらの物質の低融点を考慮して適宜決定されることが好ましい。後述する第二実施形態における閾値も同様に、適宜決定される。 Here, the first and second thresholds T 12 and T 34 are used for the ash adhesion status, the component analysis values of fuel and combustion ash, the ash adhesion status to the pipe at the time of periodic inspection, the corrosion status of the pipe, and the like. It is a value appropriately determined based on, for example, the melting point of ash contained in the exhaust gas, the specific temperature set by the requirements of the turbine 100 connected to the boiler system 1 and the 101 side, and the like are adopted as predetermined threshold values. be able to. In addition to chlorine, the fuel may contain alkali metals (sodium, potassium, etc.), and the chlorides and sulfides produced by chlorine, sodium, potassium, etc. are the combustion field temperature (about 870) in the furnace 2. It may have a melting point lower than (° C.). Examples of low melting point substances include sodium chloride, calcium chloride, potassium chloride, sodium sulfate, potassium sulfate, potassium pyrosulfate, sodium or potassium trisulfide (Na 3 Fe (SO 4 ) 3 , K 3 Fe (SO 4 )). 3 ), etc. The first and second thresholds T 12 and T 34 are preferably determined as appropriate in consideration of the low melting points of these substances. Similarly, the threshold value in the second embodiment described later is also appropriately determined.
　本実施形態におけるポンプ７及び第一・第二給水配管７ａ、７ｂ（供給部）と、第一調整弁１８及び第二調整弁１９と、制御部３０と、によって、第一接続管１４及び第二接続管１５の内部に水を供給することにより第一接続管１４及び第二接続管１５を流通する蒸気の温度を所定温度よりも低下させる「蒸気温度制御部」が構成されることとなる。 The pump 7, the first and second water supply pipes 7a and 7b (supply unit), the first adjustment valve 18, the second adjustment valve 19, and the control unit 30 in the present embodiment provide the first connection pipe 14 and the first connection pipe. (Ii) By supplying water to the inside of the connecting pipe 15, a "steam temperature control unit" that lowers the temperature of the steam flowing through the first connecting pipe 14 and the second connecting pipe 15 below a predetermined temperature is configured. ..
　本実施形態に係るボイラシステム１には、図２に示すように、タービン（同軸上に配置されるタービン１００及びタービン１０１）が接続される。タービン１００には、過熱器１０から配管１０ａを通って蒸気が供給され、タービン１０１には、後述する再熱器４０からの蒸気（再熱蒸気）が供給され、これによりタービン１００・１０１が回転して発電を行う。タービン１００から排出された蒸気の圧力と温度は、過熱器１０から排出される蒸気の圧力と温度よりも低い。特に限定されるものではないが、タービン１００へ供給される蒸気の圧力は、約１０～１７ＭＰａ程度であり、温度は約５３０～５７０℃ 程度となる。タービン１００から排出される蒸気の圧力は、約３～５ＭＰａ程度であり、温度は約３５０～４００℃ 程度となる。なお、タービン１０１の下流には復水器１０２が設けられている。タービン１０１から排出された蒸気は復水器１０２に供給され、復水器１０２において凝縮して飽和水に戻された上でポンプ７へと供給される。 As shown in FIG. 2, a turbine (turbine 100 and turbine 101 arranged coaxially) is connected to the boiler system 1 according to the present embodiment. Steam is supplied to the turbine 100 from the superheater 10 through the pipe 10a, and steam (reheated steam) from the reheater 40 described later is supplied to the turbine 101, whereby the turbines 100 and 101 rotate. To generate electricity. The pressure and temperature of the steam discharged from the turbine 100 is lower than the pressure and temperature of the steam discharged from the superheater 10. Although not particularly limited, the pressure of the steam supplied to the turbine 100 is about 10 to 17 MPa, and the temperature is about 530 to 570 ° C. The pressure of the steam discharged from the turbine 100 is about 3 to 5 MPa, and the temperature is about 350 to 400 ° C. A condenser 102 is provided downstream of the turbine 101. The steam discharged from the turbine 101 is supplied to the condenser 102, condensed in the condenser 102, returned to saturated water, and then supplied to the pump 7.
　本実施形態に係るボイラシステム１は、図２に示すように、タービン１００から排出された蒸気を再加熱する再熱器４０を備えている。再熱器４０は、蒸気を流通させる再熱器管４０ａを有している。タービン１００と再熱器４０とは、タービン１００から排出された蒸気を再熱器４０へ供給するためのタービン抽気配管１００ａで接続されている。また、再熱器４０とタービン１０１とは、再熱器４０で再加熱された蒸気をタービン１０１へ供給するためのタービン給気配管１０１ａで接続されている。よって、タービン抽気配管１００ａを介して再熱器４０へ供給された蒸気は、再熱器４０で熱交換によって再加熱された後、タービン給気配管１０１ａを介して下流側のタービン１０１へ供給される。 As shown in FIG. 2, the boiler system 1 according to the present embodiment includes a reheater 40 that reheats the steam discharged from the turbine 100. The reheater 40 has a reheater tube 40a for circulating steam. The turbine 100 and the reheater 40 are connected by a turbine bleeding pipe 100a for supplying the steam discharged from the turbine 100 to the reheater 40. Further, the reheater 40 and the turbine 101 are connected by a turbine air supply pipe 101a for supplying the steam reheated by the reheater 40 to the turbine 101. Therefore, the steam supplied to the reheater 40 via the turbine bleeding pipe 100a is reheated by heat exchange in the reheater 40 and then supplied to the turbine 101 on the downstream side via the turbine air supply pipe 101a. To.
　再熱器４０の上流側には、再熱器管４０ａの入口における蒸気温度Ｔ５を検出する入口温度センサ５１が設けられており、再熱器４０の下流側には、再熱器管４０ａの出口における蒸気温度Ｔ６を検出する出口温度センサ５２が設けられている。入口温度センサ５１及び出口温度センサ５２もまた、本発明における温度検出部に対応するものである。入口温度センサ５１及び出口温度センサ５２で検出された蒸気温度に関する情報は、制御部３０に送られて、後述する第三調整弁６０の制御に用いられる。また、タービン１００と再熱器４０とを接続するタービン抽気配管１００ａは、第二給水配管７ｂから分岐する第三給水配管７ｃによってポンプ７と接続されており、蒸気冷却用の水が、ポンプ７から第三給水配管７ｃを経由してタービン抽気配管１００ａ（ひいては再熱器管４０ａ）に供給されるようになっている。ポンプ７及び第三給水配管７ｃは、本発明における供給部に対応するものである。 The upstream side of the reheater 40, and the inlet temperature sensor 51 is provided for detecting the steam temperature T 5 at the inlet of the reheater tubes 40a, on the downstream side of the reheater 40, reheater tubes 40a An outlet temperature sensor 52 for detecting the steam temperature T 6 at the outlet of the above is provided. The inlet temperature sensor 51 and the outlet temperature sensor 52 also correspond to the temperature detection unit in the present invention. Information about the steam temperature detected by the inlet temperature sensor 51 and the outlet temperature sensor 52 is sent to the control unit 30 and used for controlling the third regulating valve 60, which will be described later. Further, the turbine bleeding pipe 100a connecting the turbine 100 and the reheater 40 is connected to the pump 7 by a third water supply pipe 7c branching from the second water supply pipe 7b, and the water for steam cooling is supplied to the pump 7. Is supplied to the turbine bleeding pipe 100a (and by extension, the reheater pipe 40a) via the third water supply pipe 7c. The pump 7 and the third water supply pipe 7c correspond to the supply unit in the present invention.
　第三給水配管７ｃには、第三給水配管７ｃ内を流通する水の流量を調整する第三調整弁６０が設けられている。第三調整弁６０は、制御部３０から送られる制御信号によって制御されることにより、タービン抽気配管１００ａ（再熱器管４０ａ）への水の供給量を調整するように機能する。制御部３０は、入口温度センサ５１及び出口温度センサ５２で検出された蒸気温度Ｔ５、Ｔ６に基づいて第三調整弁６０を制御することにより、タービン抽気配管１００ａ（再熱器管４０ａ）内に供給される水の流量を制御する。さらに具体的には、制御部３０は、入口温度センサ５１及び出口温度センサ５２で検出された蒸気温度Ｔ５、Ｔ６の平均値が第三の閾値Ｔ５６を超えた場合に、タービン抽気配管１００ａ（再熱器管４０ａ）内の蒸気温度を低下させ、その結果、再熱器４０の再熱器管４０ａの入口における蒸気温度Ｔ５（タービン抽気配管１００ａ内の蒸気温度）を第三の閾値Ｔ５６よりも低下させるように第三調整弁６０を制御する。第三の閾値Ｔ５６は、第一及び第二の閾値Ｔ１２、Ｔ３４と同様に、灰の付着状況等に基づいて適宜決定される値である。 The third water supply pipe 7c is provided with a third regulating valve 60 that adjusts the flow rate of water flowing through the third water supply pipe 7c. The third regulating valve 60 functions to adjust the amount of water supplied to the turbine bleeding pipe 100a (reheater pipe 40a) by being controlled by a control signal sent from the control unit 30. The control unit 30 controls the third regulating valve 60 based on the steam temperatures T 5 and T 6 detected by the inlet temperature sensor 51 and the outlet temperature sensor 52, thereby controlling the turbine bleeding pipe 100a (reheater pipe 40a). Control the flow rate of water supplied inside. More specifically, the control unit 30 determines the turbine bleeding pipe when the average value of the steam temperatures T 5 and T 6 detected by the inlet temperature sensor 51 and the outlet temperature sensor 52 exceeds the third threshold value T 56. 100a reduces the steam temperature in (reheater tube 40a), as a result, the reheater tubes 40a reheater 40 the steam temperature T 5 at the inlet (steam temperature in the turbine extraction pipe 100a) of the third The third regulating valve 60 is controlled so as to be lower than the threshold value T 56. The third threshold value T 56 is a value appropriately determined based on the adhesion state of ash and the like, similarly to the first and second threshold values T 12 and T 34.
　本実施形態におけるポンプ７及び第三給水配管７ｃ（供給部）と、第三調整弁６０と、制御部３０と、によって、タービン抽気配管１００ａ（再熱器管４０ａ）の内部に水を供給することによりタービン抽気配管１００ａ（再熱器管４０ａ）を流通する蒸気の温度を所定温度よりも低下させる「蒸気温度制御部」が構成されることとなる。 Water is supplied to the inside of the turbine bleeding pipe 100a (reheater pipe 40a) by the pump 7, the third water supply pipe 7c (supply unit), the third regulating valve 60, and the control unit 30 in the present embodiment. As a result, a "steam temperature control unit" that lowers the temperature of the steam flowing through the turbine bleeding pipe 100a (reheater pipe 40a) below a predetermined temperature is configured.
　次に、図３のフローチャートを用いて、本実施形態に係るボイラシステム１の蒸気温度を制御する方法について説明する。 Next, a method of controlling the steam temperature of the boiler system 1 according to the present embodiment will be described with reference to the flowchart of FIG.
　まず、ボイラシステム１の制御部３０は、第一温度センサ１６ａ及び第二温度センサ１６ｂを用いて、第二過熱部１２の過熱器管１２ａの入口及び出口における蒸気温度Ｔ１、Ｔ２を検出する（第一第二温度検出工程：Ｓ１）とともに、第三温度センサ１６ｃ及び第四温度センサ１６ｄを用いて、第三過熱部１３の過熱器管１３ａの入口及び出口における蒸気温度Ｔ３、Ｔ４を検出する（第三第四温度検出工程：Ｓ２）。さらに、制御部３０は、入口温度センサ５１及び出口温度センサ５２を用いて、再熱器４０の再熱器管４０ａの入口及び出口における蒸気温度Ｔ５、Ｔ６を検出する（入口出口温度検出工程：Ｓ３）。 First, the control unit 30 of the boiler system 1 detects the steam temperatures T 1 and T 2 at the inlet and outlet of the superheater tube 12a of the second superheating unit 12 by using the first temperature sensor 16a and the second temperature sensor 16b. (1st and 2nd temperature detection step: S1), using the 3rd temperature sensor 16c and the 4th temperature sensor 16d, the steam temperatures T 3 and T at the inlet and outlet of the superheater tube 13a of the third superheating unit 13. 4 is detected (third and fourth temperature detection steps: S2). Further, the control unit 30 detects the steam temperatures T 5 and T 6 at the inlet and outlet of the reheater tube 40a of the reheater 40 by using the inlet temperature sensor 51 and the outlet temperature sensor 52 (inlet / outlet temperature detection). Step: S3).
　次いで、ボイラシステム１の制御部３０は、第一第二温度検出工程Ｓ１で検出された蒸気温度Ｔ１、Ｔ２の平均値が第一の閾値Ｔ１２を超えた場合に、第一調整弁１８を制御して第一接続管１４内に供給される水の流量を制御することにより、第一接続管１４内の蒸気温度を低下させ、その結果、第二過熱部１２の過熱器管１２ａの入口における蒸気温度Ｔ１を第一の閾値Ｔ１２よりも低下させる（第一蒸気温度制御工程：Ｓ４）。また、制御部３０は、第三第四温度検出工程Ｓ２で検出された蒸気温度Ｔ３、Ｔ４の平均値が第二の閾値Ｔ３４を超えた場合に、第二調整弁１９を制御して第二接続管１５内に供給される水の流量を制御することにより、第二接続管１５内の蒸気温度を低下させ、その結果、第三過熱部１３の過熱器管１３ａの入口における蒸気温度Ｔ３を第二の閾値Ｔ３４よりも低下させる（第二蒸気温度制御工程：Ｓ５）。さらに、制御部３０は、入口出口温度検出工程Ｓ３で検出された蒸気温度Ｔ５、Ｔ６の平均値が第三の閾値Ｔ５６を超えた場合に、第三調整弁６０を制御してタービン抽気配管１００ａ（再熱器管４０ａ）内に供給される水の流量を制御することにより、タービン抽気配管１００ａ（再熱器管４０ａ）内の蒸気温度を低下させ、その結果、再熱器４０の再熱器管４０ａの入口における蒸気温度Ｔ５を第三の閾値Ｔ５６よりも低下させる（第三蒸気温度制御工程：Ｓ６）。 Next, the control unit 30 of the boiler system 1 determines the first regulating valve when the average value of the steam temperatures T 1 and T 2 detected in the first and second temperature detection steps S1 exceeds the first threshold value T 12. By controlling 18 to control the flow rate of water supplied into the first connecting pipe 14, the steam temperature in the first connecting pipe 14 is lowered, and as a result, the superheater pipe 12a of the second superheating portion 12 The steam temperature T 1 at the inlet of the above is lowered below the first threshold value T 12 (first steam temperature control step: S4). Further, the control unit 30 controls the second regulating valve 19 when the average value of the steam temperatures T 3 and T 4 detected in the third and fourth temperature detection steps S2 exceeds the second threshold value T 34. By controlling the flow rate of water supplied into the second connecting pipe 15, the steam temperature in the second connecting pipe 15 is lowered, and as a result, the steam at the inlet of the superheater pipe 13a of the third superheater portion 13 The temperature T 3 is lowered below the second threshold T 34 (second steam temperature control step: S5). Further, the control unit 30 controls the third regulating valve 60 to control the turbine when the average value of the steam temperatures T 5 and T 6 detected in the inlet / outlet temperature detection step S3 exceeds the third threshold value T 56. By controlling the flow rate of water supplied into the bleed air pipe 100a (reheater pipe 40a), the steam temperature in the turbine bleed air pipe 100a (reheater pipe 40a) is lowered, and as a result, the reheater 40 The steam temperature T 5 at the inlet of the reheater tube 40a is lowered below the third threshold value T 56 (third steam temperature control step: S6).
　なお、本実施形態においては、第二過熱部１２（第三過熱部１３）の過熱器管１２ａ（１３ａ）の入口及び出口における蒸気温度Ｔ１、Ｔ２（Ｔ３、Ｔ４）の平均値に基づいて第一調整弁１８（第二調整弁１９）を制御した例を示したが、第一調整弁１８（第二調整弁１９）の制御態様はこれに限られるものではない。例えば、第二過熱部１２（第三過熱部１３）の過熱器管１２ａ（１３ａ）の入口及び出口における蒸気温度Ｔ１、Ｔ２（Ｔ３、Ｔ４）の差に基づいて第一調整弁１８（第二調整弁１９）を制御することもできる。 In this embodiment, the average values of the steam temperatures T 1 , T 2 (T 3 , T 4 ) at the inlet and outlet of the superheater tube 12a (13a) of the second superheater portion 12 (third superheater portion 13). Although an example in which the first regulating valve 18 (second regulating valve 19) is controlled is shown based on the above, the control mode of the first regulating valve 18 (second regulating valve 19) is not limited to this. For example, the first regulating valve is based on the difference in steam temperatures T 1 , T 2 (T 3 , T 4 ) at the inlet and outlet of the superheater tube 12a (13a) of the second superheater 12 (third superheater 13). 18 (second regulating valve 19) can also be controlled.
　図４は、本実施形態に係るボイラシステム１の蒸気温度の変化の一例を示すものである。 FIG. 4 shows an example of a change in the steam temperature of the boiler system 1 according to the present embodiment.
　ボイラシステム１の節炭器２０においては、排ガスの熱によりボイラ給水を予熱し、所定の温度まで上昇させて蒸気ドラム８に供給する。蒸気ドラム８に供給されたボイラ給水の蒸気は、火炉２の燃焼によって加熱され、飽和蒸気温度まで上昇した状態で過熱器１０の第一過熱部１１に供給される。第一過熱部１１に供給された蒸気は、排ガスの熱によって例えば蒸気温度約４５０℃まで過熱された状態で第一接続管１４を経由して第二過熱部１２に供給される。 In the economizer 20 of the boiler system 1, the boiler water supply is preheated by the heat of the exhaust gas, raised to a predetermined temperature, and supplied to the steam drum 8. The steam of the boiler supply water supplied to the steam drum 8 is heated by the combustion of the fireplace 2, and is supplied to the first superheater 11 of the superheater 10 in a state where the temperature has risen to the saturated steam temperature. The steam supplied to the first superheated section 11 is supplied to the second superheated section 12 via the first connecting pipe 14 in a state of being superheated to, for example, a steam temperature of about 450 ° C. by the heat of the exhaust gas.
　制御部３０は、第一調整弁１８を制御して第一接続管１４内に水を供給することにより、第一接続管１４内の蒸気温度を低下させる。この際、制御部３０は、既に述べたように、第二過熱部１２の過熱器管１２ａの入口及び出口における蒸気温度Ｔ１、Ｔ２に基づいて第一調整弁１８を制御して第一接続管１４内に供給される水の流量を制御することにより第一接続管１４内の蒸気温度を低下させ、その結果、第二過熱部１２の過熱器管１２ａの入口における蒸気温度Ｔ１を第一の閾値Ｔ１２よりも低下させる。第一調整弁１８の制御に用いる第一の閾値Ｔ１２は、目標とする主蒸気温度（タービン１００に供給されるべき蒸気の温度）に応じて適宜設定することができる。 The control unit 30 controls the first regulating valve 18 to supply water into the first connecting pipe 14, thereby lowering the steam temperature in the first connecting pipe 14. At this time, as described above, the control unit 30 controls the first regulating valve 18 based on the steam temperatures T 1 and T 2 at the inlet and outlet of the superheater tube 12a of the second superheater unit 12, and first. lowering the steam temperature in the first connecting pipe 14 by controlling the flow rate of water supplied to the connecting pipe 14, as a result, the steam temperatures T 1 at the inlet of the superheater tubes 12a of the second heating section 12 It is lower than the first threshold T 12. The first threshold value T 12 used for controlling the first regulating valve 18 can be appropriately set according to the target main steam temperature (temperature of steam to be supplied to the turbine 100).
　例えば、目標とする主蒸気温度が比較的高い値（例えば約５５０℃）である場合には、第一調整弁１８の制御に用いる第一の閾値Ｔ１２も比較的高い値（例えば約４５０℃）に設定する。すると、図４の上のグラフＧ１に示されるように、第二過熱部１２の入口における蒸気温度Ｔ１は、第一の閾値Ｔ１２よりも低い温度に調整される。一方、目標とする主蒸気温度が比較的低い値（例えば約５００℃）である場合には、第一調整弁１８の制御に用いる第一の閾値Ｔ１２も比較的低い値（例えば約４００℃）に設定する。すると、図４の下のグラフＧ２に示されるように、第二過熱部１２の入口における蒸気温度Ｔ１は、第一の閾値Ｔ１２よりも低い温度に調整される。このように、何れの場合も、第一接続管１４内を流通する蒸気の温度を低下させることができ、第二過熱部１２の過熱器管１２ａ内を流通する蒸気の温度をも低下させることができる。 For example, when the target main steam temperature is a relatively high value (for example, about 550 ° C.), the first threshold value T 12 used for controlling the first regulating valve 18 is also a relatively high value (for example, about 450 ° C.). ). Then, as shown in the graph G 1 on the 4, the steam temperatures T 1 at the inlet of the second heating unit 12 is adjusted to a temperature lower than the first threshold T 12. On the other hand, when the target main steam temperature is a relatively low value (for example, about 500 ° C.), the first threshold value T 12 used for controlling the first regulating valve 18 is also a relatively low value (for example, about 400 ° C.). ). Then, as shown in the graph G 2 at the bottom of FIG. 4, the steam temperature T 1 at the inlet of the second superheated portion 12 is adjusted to a temperature lower than the first threshold value T 12. In this way, in either case, the temperature of the steam flowing in the first connecting pipe 14 can be lowered, and the temperature of the steam flowing in the superheater pipe 12a of the second superheater portion 12 can also be lowered. Can be done.
　また、制御部３０は、第二調整弁１９を制御して第二接続管１５内に水を供給することにより、第二接続管１５内の蒸気温度を低下させる。この際、制御部３０は、既に述べたように、第三過熱部１３の過熱器管１３ａの入口及び出口における蒸気温度Ｔ３、Ｔ４に基づいて第二調整弁１９を制御して第二接続管１５内に供給される水の流量を制御することにより第二接続管１５内の蒸気温度を低下させ、その結果、第三過熱部１３の過熱器管１３ａの入口における蒸気温度Ｔ３を第二の閾値Ｔ３４よりも低下させる。第二調整弁１９の制御に用いる第二の閾値Ｔ３４は、目標とする主蒸気温度（タービン１００に供給されるべき蒸気の温度）に応じて適宜設定することができる。 Further, the control unit 30 controls the second regulating valve 19 to supply water into the second connecting pipe 15 to lower the steam temperature in the second connecting pipe 15. At this time, the control unit 30, as already mentioned, the second controls the second control valve 19 based on the steam temperature T 3, T 4 at the inlet and outlet of the superheater tube 13a of the third superheated portion 13 lowering the steam temperature of the second connecting pipe 15 by controlling the flow rate of water supplied into the connection tube 15, as a result, the steam temperature T 3 at the inlet of the superheater tubes 13a of the third superheated portion 13 Lower than the second threshold T 34. The second threshold value T 34 used for controlling the second regulating valve 19 can be appropriately set according to the target main steam temperature (temperature of steam to be supplied to the turbine 100).
　例えば、目標とする主蒸気温度が比較的高い値（例えば約５５０℃）である場合には、第二調整弁１９の制御に用いる第二の閾値Ｔ３４も比較的高い値（例えば約５００℃）に設定する。すると、図４の上のグラフＧ１に示されるように、第三過熱部１２の入口における蒸気温度Ｔ３は、第二の閾値Ｔ３４よりも低い温度に調整される。一方、目標とする主蒸気温度が比較的低い値（例えば約５００℃）である場合には、第二調整弁１９の制御に用いる第二の閾値Ｔ３４も比較的低い値（例えば約４５０℃）に設定する。すると、図４の下のグラフＧ２に示されるように、第三過熱部１３の入口における蒸気温度Ｔ３は、第二の閾値Ｔ３４よりも低い温度に調整される。このように、何れの場合も、第二接続管１５内を流通する蒸気の温度を低下させることができ、第三過熱部１３の過熱器管１３ａ内を流通する蒸気の温度をも低下させることができる。 For example, when the target main steam temperature is a relatively high value (for example, about 550 ° C.), the second threshold value T 34 used for controlling the second regulating valve 19 is also a relatively high value (for example, about 500 ° C.). ). Then, as shown in the graph G 1 on the 4, steam temperature T 3 at the inlet of the third superheated portion 12 is adjusted to a temperature lower than the second threshold T 34. On the other hand, when the target main steam temperature is a relatively low value (for example, about 500 ° C.), the second threshold value T 34 used for controlling the second regulating valve 19 is also a relatively low value (for example, about 450 ° C.). ). Then, as shown in the graph G 2 in the bottom of FIG. 4, steam temperature T 3 at the inlet of the third superheated portion 13 is adjusted to a temperature lower than the second threshold T 34. In this way, in either case, the temperature of the steam flowing in the second connecting pipe 15 can be lowered, and the temperature of the steam flowing in the superheater pipe 13a of the third superheater portion 13 can also be lowered. Can be done.
　以上説明した実施形態に係るボイラシステム１においては、管（第一接続管１４、第二接続管１５、再熱器管４０ａ）の内部に水を供給することにより、管を流通する蒸気温度を所定温度よりも低下させることができるので、排ガスの温度を低下させる従来の手法よりも管の表面温度を効率良く低下させることができる。従って、管の表面に溶融灰が付着することを抑制して、管の高温腐食を抑制することができる。 In the boiler system 1 according to the above-described embodiment, the steam temperature flowing through the pipes is set by supplying water to the inside of the pipes (first connecting pipe 14, second connecting pipe 15, reheater pipe 40a). Since the temperature can be lowered below a predetermined temperature, the surface temperature of the pipe can be lowered more efficiently than the conventional method of lowering the temperature of the exhaust gas. Therefore, it is possible to suppress the adhesion of molten ash to the surface of the pipe and suppress the high temperature corrosion of the pipe.
　また、以上説明した実施形態に係るボイラシステム１においては、温度検出部（第一温度センサ１６ａ、第二温度センサ１６ｂ、第三温度センサ１６ｃ、第四温度センサ１６ｄ、入口温度センサ５１、出口温度センサ５２）で検出された蒸気温度（Ｔ１、Ｔ２、Ｔ３、Ｔ４、Ｔ５、Ｔ６）に基づいて調整弁（第一調整弁１８、第二調整弁１９、第三調整弁６０）を制御することにより、管（第一接続管１４、第二接続管１５、再熱器管４０ａ）内に供給される水の流量を制御部３０で制御することができる。従って、蒸気温度に応じて適切な制御を行うことができる。特に、本実施形態に係るボイラシステム１においては、温度検出部で検出された蒸気温度が所定の閾値（Ｔ１２、Ｔ３４、Ｔ５６）を超えた場合に、管内の蒸気温度を当該閾値よりも低下させるように制御部３０で調整弁を制御することができる。 Further, in the boiler system 1 according to the embodiment described above, the temperature detection unit (first temperature sensor 16a, second temperature sensor 16b, third temperature sensor 16c, fourth temperature sensor 16d, inlet temperature sensor 51, outlet temperature). Adjustment valves (first adjustment valve 18, second adjustment valve 19, third adjustment valve) based on the steam temperature (T 1 , T 2 , T 3 , T 4 , T 5 , T 6 ) detected by the sensor 52). By controlling 60), the flow rate of water supplied into the pipes (first connecting pipe 14, second connecting pipe 15, reheater pipe 40a) can be controlled by the control unit 30. Therefore, appropriate control can be performed according to the steam temperature. In particular, in the boiler system 1 according to the present embodiment, when the steam temperature detected by the temperature detection unit exceeds a predetermined threshold value (T 12 , T 34 , T 56 ), the steam temperature in the pipe is set from the threshold value. The control valve 30 can control the regulating valve so as to reduce the temperature.
　また、以上説明した実施形態に係るボイラシステム１においては、第一温度センサ１６ａ及び第二温度センサ１６ｂで検出された蒸気温度（第二過熱部１２の過熱器管１２ａの入口及び出口の蒸気温度）Ｔ１、Ｔ２に基づいて第一調整弁１８を制御することにより、第二過熱部１２の過熱器管１２ａ内の蒸気温度Ｔ１、Ｔ２を第一の閾値Ｔ１２よりも低下させるとともに、第三温度センサ１６ｃ及び第四温度センサ１６ｄで検出された蒸気温度（第三過熱部１３の過熱器管１３ａの入口及び出口の蒸気温度）Ｔ３、Ｔ４に基づいて第二調整弁１９を制御することにより、第三過熱部１３の過熱器管１３ａ内の蒸気温度Ｔ３、Ｔ４を第二の閾値Ｔ３４よりも低下させることができる。従って、第二過熱部１２の過熱器管１２ａ及び第三過熱部１３の過熱器管１３ａの高温腐食を抑制することができる。また、本実施形態においては、第二の閾値Ｔ３４を第一の閾値Ｔ１２よりも大きい値に設定しているため、蒸気温度が徐々に上昇するように制御することが可能となる。 Further, in the boiler system 1 according to the embodiment described above, the steam temperature detected by the first temperature sensor 16a and the second temperature sensor 16b (the steam temperature at the inlet and outlet of the superheater tube 12a of the second superheater portion 12). ) By controlling the first regulating valve 18 based on T 1 and T 2 , the steam temperatures T 1 and T 2 in the superheater tube 12 a of the second superheater 12 are lowered below the first threshold T 12. At the same time, the second regulating valve is based on the steam temperature (steam temperature at the inlet and outlet of the superheater tube 13a of the third superheating unit 13) T 3 and T 4 detected by the third temperature sensor 16c and the fourth temperature sensor 16d. By controlling 19, the steam temperatures T 3 and T 4 in the superheater tube 13 a of the third superheater 13 can be lowered below the second threshold value T 34. Therefore, high temperature corrosion of the superheater tube 12a of the second superheater portion 12 and the superheater tube 13a of the third superheater portion 13 can be suppressed. Further, in the present embodiment, since the second threshold value T 34 is set to a value larger than the first threshold value T 12, it is possible to control so that the steam temperature gradually rises.
　また、以上説明した実施形態に係るボイラシステム１においては、入口温度センサ５１及び出口温度センサ５２で検出された蒸気温度（再熱器４０の再熱器管４０ａの入口及び出口における蒸気温度）Ｔ５、Ｔ６に基づいて第三調整弁６０を制御することにより、タービン抽気配管１００ａ内（再熱器４０の再熱器管４０ａ内）の蒸気温度を第三の閾値Ｔ５６よりも低下させることができる。従って、再熱器４０の再熱器管４０ａの高温腐食を抑制することができる。 Further, in the boiler system 1 according to the above-described embodiment, the steam temperature (steam temperature at the inlet and outlet of the reheater tube 40a of the reheater 40) T detected by the inlet temperature sensor 51 and the outlet temperature sensor 52. 5, by controlling the third control valve 60 on the basis of T 6, is lower than the steam temperature within the turbine extraction pipe 100a (reheater tube 40a reheater 40) a third threshold T 56 be able to. Therefore, high temperature corrosion of the reheater tube 40a of the reheater 40 can be suppressed.
＜第二実施形態＞
　次に、図５及び図６を用いて、本発明の第二実施形態に係るボイラシステムについて説明する。本実施形態に係るボイラシステムは、第一実施形態に係るボイラシステム１の温度センサ及び制御部の構成を変更したものであり、その他の構成については第一実施形態と実質的に同一である。このため、第一実施形態と異なる構成について主に説明し、共通する構成については同一の符号を付して詳細な説明を省略することとする。 <Second embodiment>
Next, the boiler system according to the second embodiment of the present invention will be described with reference to FIGS. 5 and 6. The boiler system according to the present embodiment is a modification of the configuration of the temperature sensor and the control unit of the boiler system 1 according to the first embodiment, and other configurations are substantially the same as those of the first embodiment. Therefore, the configurations different from those of the first embodiment will be mainly described, and the common configurations will be designated by the same reference numerals and detailed description thereof will be omitted.
　本実施形態に係るボイラシステムの過熱器１０は、図５に示すように、第一過熱部１１と、第二過熱部１２と、第三過熱部１３と、を有しており、第一過熱部１１、第二過熱部１２及び第三過熱部１３は各々、蒸気を流通させる過熱器管１１ａ、１２ａ、１３ａを有しており、第一過熱部１１と第二過熱部１２は第一接続管１４で接続され、第二過熱部１２と第三過熱部１３は第二接続管１５で接続されている。これらの構成については、第一実施形態と同様であるので詳細な説明を省略する。 As shown in FIG. 5, the superheater 10 of the boiler system according to the present embodiment has a first superheater portion 11, a second superheater portion 12, and a third superheater portion 13, and has a first superheater. The unit 11, the second superheated unit 12, and the third superheated unit 13 each have superheater tubes 11a, 12a, and 13a for passing steam, and the first superheated unit 11 and the second superheated unit 12 are first connected. It is connected by a pipe 14, and the second superheated portion 12 and the third superheated portion 13 are connected by a second connecting pipe 15. Since these configurations are the same as those in the first embodiment, detailed description thereof will be omitted.
　第二過熱部１２の下流側には、第二過熱部１２の過熱器管１２ａの出口における蒸気温度Ｔ１Ａを検出する第一下流温度センサ１６が設けられている。また、第三過熱部１３の下流側には、過熱器管１３ａの出口における蒸気温度Ｔ２Ａを検出する第二下流温度センサ１７が設けられている。第一下流温度センサ１６及び第二下流温度センサ１７で検出された蒸気温度に関する情報は、後述する制御部３０Ａに送られて各種調整弁の制御に用いられる。第一下流温度センサ１６及び第二下流温度センサ１７は、本発明における温度検出部に対応するものである。 A first downstream temperature sensor 16 for detecting the steam temperature T 1A at the outlet of the superheater tube 12a of the second superheater 12 is provided on the downstream side of the second superheater 12. Further, on the downstream side of the third superheater portion 13, a second downstream temperature sensor 17 for detecting the steam temperature T 2A at the outlet of the superheater tube 13a is provided. Information about the steam temperature detected by the first downstream temperature sensor 16 and the second downstream temperature sensor 17 is sent to the control unit 30A described later and used for controlling various control valves. The first downstream temperature sensor 16 and the second downstream temperature sensor 17 correspond to the temperature detection unit in the present invention.
　第一過熱部１１と第二過熱部１２とを接続する第一接続管１４は、第一給水配管７ａによってポンプ７と接続され、第二過熱部１２と第三過熱部１３とを接続する第二接続管１５は、第二給水配管７ｂによって接続され、ポンプ７と第一接続管１４とを接続する第一給水配管７ａには、第一給水配管７ａ内を流通する水の流量を調整する第一調整弁１８が設けられており、ポンプ７と第二接続管１５とを接続する第二給水配管７ｂには、第二給水配管７ｂ内を流通する水の流量を調整する第二調整弁１９が設けられている。ポンプ７、第一・第二給水配管７ａ、７ｂ、第一及び第二接続管１４・１５及び第一及び第二調整弁１８・１９は、第一実施形態と同様であるので詳細な説明を省略する。 The first connecting pipe 14 connecting the first superheated portion 11 and the second superheated portion 12 is connected to the pump 7 by the first water supply pipe 7a, and connects the second superheated portion 12 and the third superheated portion 13. The two connecting pipes 15 are connected by a second water supply pipe 7b, and the first water supply pipe 7a connecting the pump 7 and the first connecting pipe 14 adjusts the flow rate of water flowing through the first water supply pipe 7a. The first regulating valve 18 is provided, and the second water supply pipe 7b that connects the pump 7 and the second connecting pipe 15 is a second regulating valve that adjusts the flow rate of water flowing through the second water supply pipe 7b. 19 is provided. The pump 7, the first and second water supply pipes 7a and 7b, the first and second connecting pipes 14 and 15 and the first and second regulating valves 18 and 19 are the same as those in the first embodiment. Omit.
　本実施形態における制御部３０Ａは、第一下流温度センサ１６及び第二下流温度センサ１７で検出された蒸気温度Ｔ１Ａ、Ｔ２Ａに基づいて第一調整弁１８及び第二調整弁１９を制御することにより、第一接続管１４及び第二接続管１５内に供給される水の流量を制御する。さらに具体的には、制御部３０Ａは、第一下流温度センサ１６及び第二下流温度センサ１７で検出された蒸気温度Ｔ１Ａ、Ｔ２Ａが各々第一及び第二の閾値ＴＴ１、ＴＴ２を超えた場合に、第一接続管１４内及び第二接続管１５内の蒸気温度を低下させ、その結果、第二過熱部１２の過熱器管１２ａの出口における蒸気温度Ｔ１Ａ及び第三過熱部１３の過熱器管１３ａの出口における蒸気温度Ｔ２Ａを第一及び第二の閾値ＴＴ１、ＴＴ２よりも各々低下させるように第一調整弁１８及び第二調整弁１９を制御する。ここで、第一及び第二の閾値ＴＴ１、ＴＴ２とは、第一実施形態と同様に、灰の付着状況等に基づいて適宜決定される値である。 The control unit 30A in the present embodiment controls the first regulating valve 18 and the second regulating valve 19 based on the steam temperatures T 1A and T 2A detected by the first downstream temperature sensor 16 and the second downstream temperature sensor 17. Thereby, the flow rate of the water supplied into the first connecting pipe 14 and the second connecting pipe 15 is controlled. More specifically, the control unit 30A, the steam temperature T 1A detected by the first downstream temperature sensor 16 and the second downstream temperature sensor 17, the first and second T 2A each of the threshold T T1, T T2 When it exceeds, the steam temperature in the first connecting pipe 14 and the second connecting pipe 15 is lowered, and as a result, the steam temperature T 1A and the third superheated portion at the outlet of the superheater pipe 12a of the second superheated portion 12 The first regulating valve 18 and the second regulating valve 19 are controlled so that the steam temperature T 2A at the outlet of the superheater tube 13a of 13 is lowered below the first and second thresholds TT 1 and TT 2, respectively. Here, the first and second thresholds T T1, T T2, similarly to the first embodiment is a value appropriately determined based on the deposition conditions of the ash or the like.
　本実施形態におけるポンプ７及び第一・第二給水配管７ａ、７ｂ（供給部）と、第一調整弁１８及び第二調整弁１９と、制御部３０Ａと、によって、第一接続管１４及び第二接続管１５の内部に水を供給することにより第一接続管１４及び第二接続管１５を流通する蒸気の温度を所定温度よりも低下させる「蒸気温度制御部」が構成されることとなる。 The pump 7, the first and second water supply pipes 7a and 7b (supply unit), the first adjusting valve 18, the second adjusting valve 19, and the control unit 30A in the present embodiment provide the first connecting pipe 14 and the first connection pipe. (Ii) By supplying water to the inside of the connecting pipe 15, a "steam temperature control unit" that lowers the temperature of the steam flowing through the first connecting pipe 14 and the second connecting pipe 15 below a predetermined temperature is configured. ..
　本実施形態に係るボイラシステムの再熱器４０の下流側には、再熱器管４０ａの出口における蒸気温度Ｔ３Ａを検出する第三下流温度センサ５０が設けられている。第三下流温度センサ５０もまた、本発明における温度検出部に対応するものである。第三下流温度センサ５０で検出された蒸気温度に関する情報は、制御部３０Ａに送られて、後述する第三調整弁６０の制御に用いられる。ポンプ７及び第三給水配管７ｃは、本発明における供給部に対応するものである。 On the downstream side of the reheater 40 of the boiler system according to the present embodiment, a third downstream temperature sensor 50 for detecting the steam temperature T 3A at the outlet of the reheater tube 40a is provided. The third downstream temperature sensor 50 also corresponds to the temperature detection unit in the present invention. Information about the steam temperature detected by the third downstream temperature sensor 50 is sent to the control unit 30A and used for controlling the third regulating valve 60, which will be described later. The pump 7 and the third water supply pipe 7c correspond to the supply unit in the present invention.
　第三給水配管７ｃには、第三給水配管７ｃ内を流通する水の流量を調整する第三調整弁６０が設けられており、第三調整弁６０は、制御部３０Ａから送られる制御信号によって制御されることにより、タービン抽気配管１００ａ（再熱器管４０ａ）への水の供給量を調整するように機能する。制御部３０Ａは、第三下流温度センサ５０で検出された蒸気温度Ｔ３Ａに基づいて第三調整弁６０を制御することにより、タービン抽気配管１００ａ（再熱器管４０ａ）内に供給される水の流量を制御する。さらに具体的には、制御部３０は、第三下流温度センサ５０で検出された蒸気温度Ｔ３Ａが第三の閾値ＴＴ３を超えた場合に、タービン抽気配管１００ａ（再熱器管４０ａ）内の蒸気温度を低下させ、その結果、再熱器４０の再熱器管４０ａの出口における蒸気温度Ｔ３Ａを第三の閾値ＴＴ３よりも低下させるように第三調整弁６０を制御する。第三の閾値ＴＴ３は、第一及び第二の閾値ＴＴ１、ＴＴ２と同様に、灰の付着状況等に基づいて適宜決定される値である。 The third water supply pipe 7c is provided with a third adjustment valve 60 that adjusts the flow rate of water flowing through the third water supply pipe 7c, and the third adjustment valve 60 receives a control signal sent from the control unit 30A. By being controlled, it functions to adjust the amount of water supplied to the turbine bleeding pipe 100a (reheater pipe 40a). The control unit 30A controls the third regulating valve 60 based on the steam temperature T 3A detected by the third downstream temperature sensor 50, so that the water supplied into the turbine bleeding pipe 100a (reheater pipe 40a) is supplied. Control the flow rate of. More specifically, the control unit 30 is inside the turbine bleeding pipe 100a (reheater pipe 40a) when the steam temperature T 3A detected by the third downstream temperature sensor 50 exceeds the third threshold T T 3. As a result, the third regulating valve 60 is controlled so that the steam temperature T 3A at the outlet of the reheater tube 40a of the reheater 40 is lowered below the third threshold value T T 3. The third threshold value T T3 is a value appropriately determined based on the adhesion state of ash and the like, similarly to the first and second threshold values T T1 and T T2.
　本実施形態におけるポンプ７及び第三給水配管７ｃ（供給部）と、第三調整弁６０と、制御部３０Ａと、によって、タービン抽気配管１００ａ（再熱器管４０ａ）の内部に水を供給することによりタービン抽気配管１００ａ（再熱器管４０ａ）を流通する蒸気の温度を所定温度よりも低下させる「蒸気温度制御部」が構成されることとなる。 Water is supplied to the inside of the turbine bleeding pipe 100a (reheater pipe 40a) by the pump 7, the third water supply pipe 7c (supply unit), the third regulating valve 60, and the control unit 30A in the present embodiment. As a result, a "steam temperature control unit" that lowers the temperature of the steam flowing through the turbine bleeding pipe 100a (reheater pipe 40a) below a predetermined temperature is configured.
　次に、図６のフローチャートを用いて、本実施形態に係るボイラシステムの蒸気温度を制御する方法について説明する。 Next, a method of controlling the steam temperature of the boiler system according to the present embodiment will be described with reference to the flowchart of FIG.
　まず、ボイラシステムの制御部３０Ａは、第一下流温度センサ１６を用いて、第二過熱部１２の過熱器管１２ａの出口における蒸気温度Ｔ１Ａを検出する（第一温度検出工程：Ｓ１Ａ）とともに、第二下流温度センサ１７を用いて、第三過熱部１３の過熱器管１３ａの出口における蒸気温度Ｔ２Ａを検出する（第二温度検出工程：Ｓ２Ａ）。さらに、制御部３０Ａは、第三下流温度センサ５０を用いて、再熱器４０の再熱器管４０ａの出口における蒸気温度Ｔ３Ａを検出する（第三温度検出工程：Ｓ３Ａ）。 First, the control unit 30A of the boiler system detects the steam temperature T 1A at the outlet of the superheater tube 12a of the second superheater unit 12 by using the first downstream temperature sensor 16 (first temperature detection step: S1A). , The second downstream temperature sensor 17 is used to detect the steam temperature T 2A at the outlet of the superheater tube 13a of the third superheater 13 (second temperature detection step: S2A). Further, the control unit 30A detects the steam temperature T 3A at the outlet of the reheater tube 40a of the reheater 40 by using the third downstream temperature sensor 50 (third temperature detection step: S3A).
　次いで、ボイラシステムの制御部３０Ａは、第一温度検出工程Ｓ１Ａで検出された蒸気温度Ｔ１Ａが第一の閾値ＴＴ１を超えた場合に、第一調整弁１８を制御して第一接続管１４内に供給される水の流量を制御することにより、第一接続管１４内の蒸気温度を低下させ、その結果、第二過熱部１２の過熱器管１２ａの出口における蒸気温度Ｔ１Ａを第一の閾値ＴＴ１よりも低下させる（第一蒸気温度制御工程：Ｓ４Ａ）。また、制御部３０Ａは、第二温度検出工程Ｓ２Ａで検出された蒸気温度Ｔ２Ａが第二の閾値ＴＴ２を超えた場合に、第二調整弁１９を制御して第二接続管１５内に供給される水の流量を制御することにより、第二接続管１５内の蒸気温度を低下させ、その結果、第三過熱部１３の過熱器管１３ａの出口における蒸気温度Ｔ２Ａを閾値ＴＴ２よりも低下させる（第二蒸気温度制御工程：Ｓ５Ａ）。さらに、制御部３０Ａは、第三温度検出工程Ｓ３Ａで検出された蒸気温度Ｔ３Ａが第三の閾値ＴＴ３を超えた場合に、第三調整弁６０を制御してタービン抽気配管１００ａ（再熱器管４０ａ）内に供給される水の流量を制御することにより、タービン抽気配管１００ａ（再熱器管４０ａ）内の蒸気温度を低下させ、その結果、再熱器４０の再熱器管４０ａの出口における蒸気温度Ｔ３Ａを閾値ＴＴ３よりも低下させる（第三蒸気温度制御工程：Ｓ６Ａ）。 Next, the control unit 30A of the boiler system controls the first regulating valve 18 when the steam temperature T 1A detected in the first temperature detection step S1A exceeds the first threshold value T T 1 , and controls the first connecting pipe. by controlling the flow rate of water supplied to the 14, to reduce the steam temperature in the first connecting pipe 14, as a result, the steam temperature T 1A at the outlet of the superheater tube 12a of the second heating unit 12 first It is lowered below one threshold T T1 (first steam temperature control step: S4A). Further, when the steam temperature T 2A detected in the second temperature detection step S2A exceeds the second threshold value T T2 , the control unit 30A controls the second regulating valve 19 and enters the second connecting pipe 15. by controlling the flow rate of water supplied, reducing the steam temperature in the second connection pipe 15, as a result, the threshold T T2 steam temperature T 2A at the outlet of the superheater tube 13a of the third superheated portion 13 Is also reduced (second steam temperature control step: S5A). Further, when the steam temperature T 3A detected in the third temperature detection step S3A exceeds the third threshold value T T3 , the control unit 30A controls the third regulating valve 60 to reheat the turbine bleed pipe 100a (reheat). By controlling the flow rate of water supplied into the vessel 40a), the steam temperature in the turbine bleeding pipe 100a (reheater pipe 40a) is lowered, and as a result, the reheater pipe 40a of the reheater 40 is lowered. The steam temperature T 3A at the outlet of is lowered below the threshold T T 3 (third steam temperature control step: S6A).
　以上説明した実施形態に係るボイラシステムにおいても、第一実施形態と同様の作用効果を得ることができる。 The boiler system according to the embodiment described above can also obtain the same effect as that of the first embodiment.
　なお、以上の各実施形態においては、三つの過熱部を有する過熱器を採用した例を示したが、過熱部の個数はこれに限られるものではなく、例えば一つのみの過熱部を有する過熱器を採用したり、二つの過熱部を有する過熱器を採用したり、四つ以上の過熱部を有する過熱器を採用したりすることもできる。 In each of the above embodiments, an example in which a superheater having three superheated parts is adopted has been shown, but the number of superheated parts is not limited to this, and for example, a superheater having only one superheated part is shown. It is also possible to adopt a device, a superheater having two superheaters, or a superheater having four or more superheaters.
　また、以上の各実施形態においては、蒸気冷却用の流体として「水」を採用した例を示したが、「水」以外の流体（例えば低温の蒸気等）を蒸気冷却用の流体として採用することもできる。 Further, in each of the above embodiments, an example in which "water" is adopted as the fluid for steam cooling is shown, but a fluid other than "water" (for example, low-temperature steam) is adopted as the fluid for steam cooling. You can also do it.
　また、以上の各実施形態においては、下流側に配置された第二調整弁１９の制御に用いる第二の閾値を、上流側に配置された第一調整弁１８の制御に用いる第一の閾値よりも大きい値に設定した例を示したが、第二の閾値を第一の閾値と同一の値に設定することもできる。 Further, in each of the above embodiments, the second threshold value used for controlling the second regulating valve 19 arranged on the downstream side is used as the first threshold value used for controlling the first regulating valve 18 arranged on the upstream side. Although an example in which the value is set to a value larger than is shown, the second threshold value can be set to the same value as the first threshold value.
　本発明は、以上の各実施形態に限定されるものではなく、これら実施形態に当業者が適宜設計変更を加えたものも、本発明の特徴を備えている限り、本発明の範囲に包含される。すなわち、前記各実施形態が備える各要素及びその配置、材料、条件、形状、サイズ等は、例示したものに限定されるわけではなく適宜変更することができる。また、前記各実施形態が備える各要素は、技術的に可能な限りにおいて組み合わせることができ、これらを組み合わせたものも本発明の特徴を含む限り本発明の範囲に包含される。 The present invention is not limited to each of the above embodiments, and those having a design modification appropriately made by those skilled in the art are also included in the scope of the present invention as long as they have the features of the present invention. To. That is, each element included in each of the above embodiments, its arrangement, material, condition, shape, size, and the like are not limited to those exemplified, and can be appropriately changed. In addition, the elements included in each of the above embodiments can be combined as much as technically possible, and the combination thereof is also included in the scope of the present invention as long as the features of the present invention are included.
　１…ボイラシステム
　７…ポンプ（供給部、蒸気温度制御部の一部）
　７ａ…第一給水配管（供給部、蒸気温度制御部の一部）
　７ｂ…第二給水配管（供給部、蒸気温度制御部の一部）
　７ｃ…第三給水配管（供給部、蒸気温度制御部の一部）
　１１…第一過熱部
　１１ａ…過熱器管
　１２…第二過熱部
　１２ａ…過熱器管
　１３…第三過熱部
　１３ａ…過熱器管
　１４…第一接続管
　１５…第二接続管
　１６…第一下流温度センサ（温度検出部）
　１６ａ…第一温度センサ（温度検出部）
　１６ｂ…第二温度センサ（温度検出部）
　１６ｃ…第三温度センサ（温度検出部）
　１６ｄ…第四温度センサ（温度検出部）
　１７…第二下流温度センサ（温度検出部）
　１８…第一調整弁（蒸気温度制御部の一部）
　１９…第二調整弁（蒸気温度制御部の一部）
　３０・３０Ａ…制御部（蒸気温度制御部の一部）
　４０…再熱器
　４０ａ…再熱器管
　５１…入口温度センサ（温度検出部）
　５２…出口温度センサ（温度検出部）
　６０…第三調整弁（蒸気温度制御部の一部）
　１００ａ…タービン抽気配管
　Ｓ４・Ｓ４Ａ…第一蒸気温度制御工程
　Ｓ５・Ｓ５Ａ…第二蒸気温度制御工程
　Ｓ６・Ｓ６Ａ…第三蒸気温度制御工程
  1 ... Boiler system 7 ... Pump (supply part, part of steam temperature control part)
7a ... First water supply pipe (supply part, part of steam temperature control part)
7b ... Second water supply pipe (supply part, part of steam temperature control part)
7c ... Third water supply pipe (supply part, part of steam temperature control part)
11 ... 1st superheater 11a ... Superheater pipe 12 ... 2nd superheater 12a ... Superheater pipe 13 ... 3rd superheater 13a ... Superheater pipe 14 ... 1st connection pipe 15 ... 2nd connection pipe 16 ... 1st downstream Temperature sensor (temperature detector)
16a ... First temperature sensor (temperature detector)
16b ... Second temperature sensor (temperature detector)
16c ... Third temperature sensor (temperature detector)
16d ... Fourth temperature sensor (temperature detector)
17 ... Second downstream temperature sensor (temperature detector)
18 ... First regulating valve (part of steam temperature control unit)
19 ... Second regulating valve (part of steam temperature control unit)
30 / 30A ... Control unit (part of steam temperature control unit)
40 ... Reheater 40a ... Reheater tube 51 ... Inlet temperature sensor (temperature detector)
52 ... Outlet temperature sensor (temperature detector)
60 ... Third regulating valve (part of steam temperature control unit)
100a ... Turbine bleeding pipe S4 / S4A ... First steam temperature control process S5 / S5A ... Second steam temperature control process S6 / S6A ... Third steam temperature control process

Claims (9)

  1. 　蒸気を流通させる管と、
    　前記管の内部に流体を供給することにより、前記管を流通する蒸気の温度を所定温度よりも低下させる蒸気温度制御部と、
    を備える、ボイラシステム。     A pipe for circulating steam,
    A steam temperature control unit that lowers the temperature of steam flowing through the pipe below a predetermined temperature by supplying a fluid to the inside of the pipe.
    Boiler system with.
  2. 　蒸気温度を検出する温度検出部を備え、
    　前記蒸気温度制御部は、
    　前記管内に前記流体を供給する供給部と、
    　前記供給部による前記流体の供給量を調整する調整弁と、
    　前記温度検出部で検出された蒸気温度に基づいて前記調整弁を制御することにより前記管内に供給される前記流体の流量を制御する制御部と、
    を有する、請求項１に記載のボイラシステム。     Equipped with a temperature detector that detects steam temperature
    The steam temperature control unit
    A supply unit that supplies the fluid into the pipe,
    A regulating valve that adjusts the amount of fluid supplied by the supply unit,
    A control unit that controls the flow rate of the fluid supplied into the pipe by controlling the adjustment valve based on the steam temperature detected by the temperature detection unit.
    The boiler system according to claim 1.
  3. 　前記制御部は、前記温度検出部で検出された蒸気温度が所定の閾値を超えた場合に、前記管内の蒸気温度を当該閾値よりも低下させるように前記調整弁を制御する、請求項２に記載のボイラシステム。 The control unit controls the regulating valve so that the steam temperature in the pipe is lowered below the threshold value when the steam temperature detected by the temperature detection unit exceeds a predetermined threshold value. Described boiler system.
  4. 　前記閾値は、前記管への灰の付着状態及び／又は前記灰の燃料性状に応じて設定される、請求項３に記載のボイラシステム。 The boiler system according to claim 3, wherein the threshold value is set according to the state of adhesion of ash to the pipe and / or the fuel property of the ash.
  5. 　第一過熱部と、前記第一過熱部よりも下流側にある第二過熱部と、前記第二過熱部よりも下流側になる第三過熱部と、を有する過熱器を備え、
    　前記管は、前記第一過熱部の過熱器管と前記第二過熱部の過熱器管とを接続する第一接続管と、前記第二過熱部の過熱器管と前記第三過熱部の過熱器管とを接続する第二接続管と、を含み、
    　前記温度検出部は、前記第二過熱部の過熱器管の入口における蒸気温度を検出する第一温度センサと、前記第二過熱部の過熱器管の出口における蒸気温度を検出する第二温度センサと、前記第三過熱部の過熱器管の入口における蒸気温度を検出する第三温度センサと、第三過熱部の過熱器管の出口における蒸気温度を検出する第四温度センサと、を含み、
    　前記供給部は、前記流体を供給するポンプと、前記ポンプと前記第一接続管とを接続する第一給水配管と、前記ポンプと前記第二接続管とを接続する第二給水配管と、を含み、
    　前記調整弁は、前記第一接続管に供給される前記流体の供給量を調整する第一調整弁と、前記第二接続管に供給される前記流体の供給量を調整する第二調整弁と、を含み、
    　前記制御部は、前記第一温度センサ及び前記第二温度センサで検出された蒸気温度に基づいて前記第一調整弁を制御することにより、前記第二過熱部の過熱器管内の蒸気温度を前記第一の閾値よりも低下させるとともに、前記第三温度センサ及び前記第四温度センサで検出された蒸気温度に基づいて前記第二調整弁を制御することにより、前記第三過熱部の過熱器管内の蒸気温度を前記第二の閾値よりも低下させる、請求項３又は４に記載のボイラシステム。     A superheater having a first superheater, a second superheater downstream of the first superheater, and a third superheater downstream of the second superheater is provided.
    The pipes are a first connecting pipe that connects the superheater pipe of the first superheater portion and the superheater pipe of the second superheater portion, and the superheater pipe of the second superheater portion and the superheater of the third superheater portion. Including a second connecting pipe that connects to the vessel,
    The temperature detection unit includes a first temperature sensor that detects the steam temperature at the inlet of the superheater tube of the second superheater, and a second temperature sensor that detects the steam temperature at the outlet of the superheater tube of the second superheater. A third temperature sensor that detects the steam temperature at the inlet of the superheater tube of the third superheater, and a fourth temperature sensor that detects the steam temperature at the outlet of the superheater tube of the third superheater.
    The supply unit includes a pump that supplies the fluid, a first water supply pipe that connects the pump and the first connecting pipe, and a second water supply pipe that connects the pump and the second connecting pipe. Including
    The regulating valve includes a first regulating valve that adjusts the supply amount of the fluid supplied to the first connecting pipe, and a second regulating valve that adjusts the supply amount of the fluid supplied to the second connecting pipe. , Including
    The control unit controls the first regulating valve based on the steam temperature detected by the first temperature sensor and the second temperature sensor, thereby controlling the steam temperature in the superheater tube of the second superheater. By lowering the temperature below the first threshold value and controlling the second regulating valve based on the steam temperature detected by the third temperature sensor and the fourth temperature sensor, the inside of the superheater tube of the third superheater portion is used. The boiler system according to claim 3 or 4, wherein the steam temperature of the above is lowered below the second threshold value.
  6. 　前記第二の閾値は、前記第一の閾値よりも大きい値である、請求項５に記載のボイラシステム。 The boiler system according to claim 5, wherein the second threshold value is a value larger than the first threshold value.
  7. 　タービンから排出された蒸気を再加熱する再熱器を備え、
    　前記管は、前記タービンと前記再熱器の再熱器管とを接続するタービン抽気配管を含み、
    　前記温度検出部は、前記再熱器の再熱器管の入口における蒸気温度を検出する入口温度センサと、前記再熱器の再熱器管の出口における蒸気温度を検出する出口温度センサと、を含み、
    　前記供給部は、前記流体を供給するポンプと、前記ポンプと前記タービン抽気配管とを接続する第三給水配管と、を含み、
    　前記調整弁は、前記タービン抽気配管に供給される前記流体の供給量を調整する第三調整弁を含み、
    　前記制御部は、前記入口温度センサ及び前記出口温度センサで検出された蒸気温度に基づいて前記第三調整弁を制御することにより、前記再熱器の再熱器管内の蒸気温度を前記第三の閾値よりも低下させる、請求項３から６の何れか一項に記載のボイラシステム。     Equipped with a reheater that reheats the steam discharged from the turbine
    The pipe includes a turbine bleed pipe connecting the turbine and the reheater pipe of the reheater.
    The temperature detection unit includes an inlet temperature sensor that detects the steam temperature at the inlet of the reheater tube of the reheater, an outlet temperature sensor that detects the steam temperature at the outlet of the reheater tube of the reheater, and the like. Including
    The supply unit includes a pump that supplies the fluid and a third water supply pipe that connects the pump and the turbine bleed pipe.
    The regulating valve includes a third regulating valve that regulates the supply amount of the fluid supplied to the turbine bleed pipe.
    The control unit controls the third regulating valve based on the steam temperature detected by the inlet temperature sensor and the outlet temperature sensor, thereby controlling the steam temperature in the reheater tube of the reheater. The boiler system according to any one of claims 3 to 6, wherein the temperature is lowered below the threshold value of.
  8. 　蒸気を流通させる管を備えるボイラシステムの蒸気温度を制御する方法であって、
    　前記管の内部に流体を供給することにより、前記管を流通する蒸気の温度を所定温度よりも低下させる蒸気温度制御工程を含む、制御方法。     A method of controlling the steam temperature of a boiler system equipped with a pipe through which steam flows.
    A control method comprising a steam temperature control step of lowering the temperature of steam flowing through the pipe below a predetermined temperature by supplying a fluid to the inside of the pipe.
  9. 　蒸気を流通させる管を備えるボイラシステムの蒸気温度を制御する方法をコンピュータに実行させるプログラムであって、
    　前記方法は、前記管の内部に流体を供給することにより、前記管を流通する蒸気の温度を所定温度よりも低下させる蒸気温度制御工程を含む、プログラム。
          A program that causes a computer to execute a method of controlling the steam temperature of a boiler system equipped with a pipe for circulating steam.
    The method comprises a steam temperature control step of supplying a fluid to the inside of the pipe to lower the temperature of steam flowing through the pipe below a predetermined temperature.
PCT/JP2020/029843 2019-08-30 2020-08-04 Boiler system, control method, and program WO2021039311A1 (en)

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