JP6115093B2

JP6115093B2 - Boiler system

Info

Publication number: JP6115093B2
Application number: JP2012251625A
Authority: JP
Inventors: 山田　和也; 和也山田; 嘉秀久保; 浩二三浦; 康弘兵頭
Original assignee: Miura Co Ltd
Current assignee: Miura Co Ltd
Priority date: 2012-11-15
Filing date: 2012-11-15
Publication date: 2017-04-19
Anticipated expiration: 2032-11-15
Also published as: JP2014098529A

Description

本発明は、ボイラシステムに関する。より詳しくは、燃焼状態の制御を比例制御で行うボイラシステムに関する。 The present invention relates to a boiler system. More specifically, the present invention relates to a boiler system that controls the combustion state by proportional control.

従来、複数のボイラを燃焼させて蒸気を発生させるボイラシステムとして、ボイラの燃焼量を連続的に増減させて蒸気の発生量を制御する、いわゆる比例制御方式のボイラシステムが提案されている。
例えば、特許文献１には、ボイラを、台数増加負荷ゾーン、最適運転負荷ゾーン及び台数減少負荷ゾーンの３つの負荷ゾーンに区分し、ボイラが台数増加負荷ゾーンで燃焼している場合に燃焼させるボイラの台数を増加させ、ボイラが台数減少負荷ゾーンで燃焼している場合に燃焼させるボイラの台数を減少させることで、ボイラ効率（ボイラによる熱の利用効率）を向上させる比例制御ボイラの制御方法が提案されている。そして、この特許文献１で提案された比例制御ボイラの制御方法では、燃焼させるボイラの台数の増減を行った後には、燃焼しているすべてのボイラを均等な負荷率で運転させている。 2. Description of the Related Art Conventionally, as a boiler system that generates steam by burning a plurality of boilers, a so-called proportional control type boiler system that controls the generation amount of steam by continuously increasing or decreasing the combustion amount of the boiler has been proposed.
For example, in Patent Document 1, a boiler is divided into three load zones, a load increase zone, an optimum operation load zone, and a load decrease load zone, and the boiler is burned when burning in the load increase load zone. There is a proportional control boiler control method that improves boiler efficiency (heat utilization efficiency by the boiler) by increasing the number of boilers and reducing the number of boilers to burn when the boiler is burning in the load reduction zone. Proposed. And in the control method of the proportional control boiler proposed by this patent document 1, after performing increase / decrease in the number of the boilers to burn, all the boilers which are burned are operated by the equal load factor.

特開平１１−１３２４０５号公報Japanese Patent Laid-Open No. 11-132405

特許文献１で提案された手法では、燃焼しているすべてのボイラを均等な負荷率（燃焼状態）で運転させるため、要求される負荷が変動するたびに、すべてのボイラの燃焼状態を変更させることとなる。そのため、この手法では、複数台のボイラの燃焼状態が頻繁に変更されることとなり、ボイラシステムにより出力される蒸気量の安定性が低下してしまう場合がある。 In the method proposed in Patent Document 1, since all the boilers that are burning are operated at an equal load factor (combustion state), the combustion state of all the boilers is changed every time the required load fluctuates. It will be. Therefore, in this method, the combustion state of a plurality of boilers is frequently changed, and the stability of the amount of steam output from the boiler system may be reduced.

従って、本発明は、ボイラ効率を高く保ちつつ、出力される蒸気量の安定性を高められるボイラシステムを提供することを目的とする。 Accordingly, an object of the present invention is to provide a boiler system that can improve the stability of the amount of steam that is output while maintaining high boiler efficiency.

本発明は、負荷率を連続的に変更して燃焼可能な複数のボイラを備えるボイラ群と、要求負荷に応じて前記ボイラ群の燃焼状態を制御する制御部と、を備えるボイラシステムであって、前記複数のボイラには、ボイラ効率が最も高くなる負荷率であるエコ運転ポイントと、ボイラ効率が第１閾値よりも高くなる負荷率の範囲であって前記エコ運転ポイントを含む負荷率の範囲であるエコ運転ゾーンと、ボイラ効率が前記第１閾値よりも低くなる負荷率の範囲であって前記エコ運転ゾーンよりも負荷率の高い範囲に位置する上側通常運転ゾーンと、ボイラ効率が前記第１閾値よりも低くなる負荷率の範囲であって前記エコ運転ゾーンよりも負荷率の低い範囲に位置する下側通常運転ゾーンと、が設定され、前記制御部は、燃焼状態にあるボイラのうちの少なくとも一台を、要求負荷の変動に応じて負荷率を変更して燃焼させる負荷追従ボイラに設定し、該負荷追従ボイラ以外のボイラを、前記エコ運転ゾーンで燃焼させるエコ運転ボイラに設定するボイラシステムに関する。 The present invention is a boiler system including a boiler group including a plurality of boilers capable of burning by continuously changing a load factor, and a control unit that controls a combustion state of the boiler group according to a required load. The plurality of boilers include an eco-operation point that is a load factor at which the boiler efficiency is highest, and a load factor range in which the boiler efficiency is higher than a first threshold value and includes the eco-operation point. The eco-operation zone, the upper normal operation zone that is located in the range of the load factor where the boiler efficiency is lower than the first threshold and the load factor is higher than the eco-operation zone, and the boiler efficiency is the first A lower normal operation zone that is located in a range of a load factor that is lower than one threshold value and that is lower than the eco-operation zone, and the control unit is in a boiler in a combustion state At least one of them is set as a load following boiler that changes the load factor according to the fluctuation of the required load and burns, and a boiler other than the load following boiler is set as an eco operation boiler that burns in the eco operation zone It relates to the boiler system.

また、前記制御部は、前記エコ運転ボイラを前記エコ運転ポイントで燃焼させることが好ましい。 Moreover, it is preferable that the said control part burns the said eco-operation boiler at the said eco-operation point.

また、前記上側通常運転ゾーンは、ボイラ効率が前記第１閾値と該第１閾値よりも低い第２閾値との間となる負荷率の範囲である第１上側通常運転ゾーンと、ボイラ効率が前記第２閾値よりも低くなる負荷率の範囲である第２上側通常運転ゾーンと、を有し、前記下側通常運転ゾーンは、ボイラ効率が前記第１閾値と該第１閾値よりも低い第２閾値との間となる負荷率の範囲である第１下側通常運転ゾーンと、ボイラ効率が前記第２閾値よりも低くなる負荷率の範囲である第２下側通常運転ゾーンと、を備え、前記制御部は、前記負荷追従ボイラの負荷率が前記第２上側通常運転ゾーンに位置する場合に、燃焼させるボイラの台数を増加させ、前記負荷追従ボイラの負荷率が前記第２下側通常運転ゾーンに位置する場合に、燃焼させるボイラの台数を減少させることが好ましい。 The upper normal operation zone includes a first upper normal operation zone in which the boiler efficiency is a load factor range between the first threshold value and a second threshold value lower than the first threshold value, and the boiler efficiency is A second upper normal operation zone that is a load factor range that is lower than the second threshold, and the lower normal operation zone has a boiler efficiency that is lower than the first threshold and the first threshold. A first lower normal operation zone that is a load factor range between the threshold and a second lower normal operation zone that is a load factor range in which the boiler efficiency is lower than the second threshold; The control unit increases the number of boilers to be burned when the load factor of the load following boiler is located in the second upper normal operation zone, and the load factor of the load following boiler becomes the second lower normal operation. Boiler to burn when located in the zone It is preferable to reduce the number.

本発明のボイラシステムによれば、ボイラ効率を高く保ちつつ、出力される蒸気量の安定性を高められる。 According to the boiler system of the present invention, it is possible to improve the stability of the output steam amount while keeping the boiler efficiency high.

本発明の一実施形態に係るボイラシステムの概略を示す図である。It is a figure showing the outline of the boiler system concerning one embodiment of the present invention. 本発明の一実施形態に係るボイラ群の概略を示す図である。It is a figure showing the outline of the boiler group concerning one embodiment of the present invention. ボイラシステムの動作の概略を示す図である。It is a figure which shows the outline of operation | movement of a boiler system. ボイラシステムの動作の概略を示す図であり、燃焼させるボイラの台数を増加させる状態を示す図である。It is a figure which shows the outline of operation | movement of a boiler system, and is a figure which shows the state which increases the number of boilers to burn. ボイラシステムの動作の概略を示す図であり、燃焼させるボイラの台数を増加させる状態を示す図である。It is a figure which shows the outline of operation | movement of a boiler system, and is a figure which shows the state which increases the number of boilers to burn. ボイラシステムの動作の概略を示す図であり、燃焼させるボイラの台数を減少させる状態を示す図である。It is a figure which shows the outline of operation | movement of a boiler system, and is a figure which shows the state which reduces the number of boilers to burn. ボイラシステムの動作の概略を示す図であり、燃焼させるボイラの台数を減少させる状態を示す図である。It is a figure which shows the outline of operation | movement of a boiler system, and is a figure which shows the state which reduces the number of boilers to burn. ボイラシステムの処理の流れを示すフローチャートである。It is a flowchart which shows the flow of a process of a boiler system.

以下、本発明のボイラシステムの好ましい実施形態について、図面を参照しながら説明する。
まず、本発明のボイラシステム１の全体構成につき、図１を参照しながら説明する。
ボイラシステム１は、複数（５台）のボイラ２０を含むボイラ群２と、これら複数のボイラ２０において生成された蒸気を集合させる蒸気ヘッダ６と、この蒸気ヘッダ６の内部の圧力を測定する蒸気圧センサ７と、ボイラ群２の燃焼状態を制御する制御部４を有する台数制御装置３と、を備える。 Hereinafter, preferred embodiments of the boiler system of the present invention will be described with reference to the drawings.
First, the overall configuration of the boiler system 1 of the present invention will be described with reference to FIG.
The boiler system 1 includes a boiler group 2 including a plurality of (five) boilers 20, a steam header 6 that collects steam generated in the plurality of boilers 20, and steam that measures the pressure inside the steam header 6. A pressure sensor 7 and a number control device 3 having a controller 4 that controls the combustion state of the boiler group 2 are provided.

ボイラ群２は、負荷機器としての蒸気使用設備１８に供給する蒸気を生成する。
蒸気ヘッダ６は、蒸気管１１を介してボイラ群２を構成する複数のボイラ２０に接続されている。この蒸気ヘッダ６の下流側は、蒸気管１２を介して蒸気使用設備１８に接続されている。
蒸気ヘッダ６は、ボイラ群２で生成された蒸気を集合させて貯留することにより、複数のボイラ２０の相互の圧力差及び圧力変動を調整し、圧力が調整された蒸気を蒸気使用設備１８に供給する。 The boiler group 2 produces | generates the vapor | steam supplied to the steam use installation 18 as a load apparatus.
The steam header 6 is connected to a plurality of boilers 20 constituting the boiler group 2 via a steam pipe 11. A downstream side of the steam header 6 is connected to a steam use facility 18 via a steam pipe 12.
The steam header 6 collects and stores the steam generated in the boiler group 2, thereby adjusting the pressure difference and pressure fluctuation of the plurality of boilers 20, and supplying the steam whose pressure is adjusted to the steam using facility 18. Supply.

蒸気圧センサ７は、信号線１３を介して、台数制御装置３に電気的に接続されている。蒸気圧センサ７は、蒸気ヘッダ６の内部の蒸気圧（ボイラ群２で発生した蒸気の圧力）を測定し、測定した蒸気圧に係る信号（蒸気圧信号）を、信号線１３を介して台数制御装置３に送信する。 The vapor pressure sensor 7 is electrically connected to the number control device 3 via the signal line 13. The steam pressure sensor 7 measures the steam pressure inside the steam header 6 (steam pressure generated in the boiler group 2), and sends a signal (steam pressure signal) related to the measured steam pressure via the signal line 13. It transmits to the control apparatus 3.

台数制御装置３は、信号線１６を介して、複数のボイラ２０と電気的に接続されている。この台数制御装置３は、蒸気圧センサ７により測定される蒸気ヘッダ６の内部の蒸気圧に基づいて、各ボイラ２０の燃焼状態を制御する。台数制御装置３の詳細については、後述する。 The number control device 3 is electrically connected to the plurality of boilers 20 through the signal line 16. The number control device 3 controls the combustion state of each boiler 20 based on the steam pressure inside the steam header 6 measured by the steam pressure sensor 7. Details of the number control device 3 will be described later.

以上のボイラシステム１は、ボイラ群２で発生させた蒸気を、蒸気ヘッダ６を介して、蒸気使用設備１８に供給可能とされている。
ボイラシステム１において要求される負荷（要求負荷）は、蒸気使用設備１８における蒸気消費量である。台数制御装置３は、この蒸気消費量の変動に対応して生じる蒸気ヘッダ６の内部の蒸気圧の変動を、蒸気圧センサ７が測定する蒸気ヘッダ６の内部の蒸気圧（物理量）に基づいて算出し、ボイラ群２を構成する各ボイラ２０の燃焼量を制御する。 The above boiler system 1 can supply the steam generated in the boiler group 2 to the steam using equipment 18 via the steam header 6.
The load required in the boiler system 1 (required load) is the amount of steam consumed in the steam using facility 18. The number control device 3 determines the fluctuation of the steam pressure inside the steam header 6 corresponding to the fluctuation of the steam consumption based on the steam pressure (physical quantity) inside the steam header 6 measured by the steam pressure sensor 7. The amount of combustion of each boiler 20 which comprises the boiler group 2 is calculated and controlled.

具体的には、蒸気使用設備１８の需要の増大により要求負荷（蒸気消費量）が増加し、蒸気ヘッダ６に供給される蒸気量が不足すれば、蒸気ヘッダ６の内部の蒸気圧が減少することになる。一方、蒸気使用設備１８の需要の低下により要求負荷（蒸気消費量）が減少し、蒸気ヘッダ６に供給される蒸気量が過剰になれば、蒸気ヘッダ６の内部の蒸気圧が増加することになる。従って、ボイラシステム１は、蒸気圧センサ７により測定された蒸気圧の変動に基づいて、要求負荷の変動をモニターすることができる。そして、ボイラシステム１は、蒸気ヘッダ６の蒸気圧に基づいて、蒸気使用設備１８の消費蒸気量（要求負荷）に応じて必要とされる蒸気量である必要蒸気量を算出する。 Specifically, if the required load (steam consumption) increases due to an increase in demand for the steam use facility 18, and the amount of steam supplied to the steam header 6 is insufficient, the steam pressure inside the steam header 6 decreases. It will be. On the other hand, if the demand load (steam consumption) decreases due to a decrease in the demand for the steam use facility 18 and the amount of steam supplied to the steam header 6 becomes excessive, the steam pressure inside the steam header 6 increases. Become. Therefore, the boiler system 1 can monitor the fluctuation of the required load based on the fluctuation of the vapor pressure measured by the vapor pressure sensor 7. Then, the boiler system 1 calculates a necessary steam amount that is a steam amount required according to the consumed steam amount (required load) of the steam using facility 18 based on the steam pressure of the steam header 6.

ここで、本実施形態のボイラシステム１を構成する複数のボイラ２０について説明する。図２は、本実施形態に係るボイラ群２の概略を示す図である。
本実施形態のボイラ２０は、負荷率を連続的に変更して燃焼可能な比例制御ボイラからなる。
比例制御ボイラとは、少なくとも、最小燃焼状態Ｓ１（例えば、最大燃焼量の２０％の燃焼量における燃焼状態）から最大燃焼状態Ｓ２の範囲で、燃焼量が連続的に制御可能とされているボイラである。比例制御ボイラは、例えば、燃料をバーナに供給するバルブや、燃焼用空気を供給するバルブの開度（燃焼比）を制御することにより、燃焼量を調整するようになっている。 Here, the several boiler 20 which comprises the boiler system 1 of this embodiment is demonstrated. FIG. 2 is a diagram showing an outline of the boiler group 2 according to the present embodiment.
The boiler 20 of this embodiment consists of a proportional control boiler which can be burned by changing the load factor continuously.
The proportional control boiler is a boiler in which the combustion amount can be continuously controlled at least in the range from the minimum combustion state S1 (for example, the combustion state at 20% of the maximum combustion amount) to the maximum combustion state S2. It is. The proportional control boiler adjusts the amount of combustion by, for example, controlling the opening degree (combustion ratio) of a valve that supplies fuel to the burner and a valve that supplies combustion air.

また、燃焼量を連続的に制御するとは、後述のローカル制御部２２における演算や信号がデジタル方式とされて段階的に取り扱われる場合（例えば、ボイラ２０の出力（燃焼量）が１％刻みで制御される場合）であっても、事実上連続的に出力を制御可能な場合を含む。 Further, the continuous control of the combustion amount means that the calculation or signal in the local control unit 22 described later is a digital method and is handled in stages (for example, the output (combustion amount) of the boiler 20 in increments of 1%). Even when the output is controlled).

本実施形態では、複数のボイラ２０には、最小燃焼状態Ｓ１における負荷率である最小負荷率Ｒ_ｍｉｎが設定されている。そして、ボイラ２０の燃焼停止状態Ｓ０と最小燃焼状態Ｓ１との間の燃焼状態の変更は、ボイラ２０（バーナ）の燃焼をオン／オフすることで制御される。そして、最小燃焼状態Ｓ１から最大燃焼状態Ｓ２の範囲においては、燃焼量が連続的に制御可能となっている。 In the present embodiment, a minimum load factor R _min that is a load factor in the minimum combustion state S1 is set for the plurality of boilers 20. And the change of the combustion state between the combustion stop state S0 and the minimum combustion state S1 of the boiler 20 is controlled by turning on / off the combustion of the boiler 20 (burner). In the range from the minimum combustion state S1 to the maximum combustion state S2, the combustion amount can be controlled continuously.

また、本実施形態では、複数のボイラ２０には、ボイラ効率が最も高くなる負荷率であるエコ運転ポイントＥＰが設定されると共に、所定の負荷率の範囲により区分された複数の運転ゾーンが設定される。
より具体的には、本実施形態では、複数の運転ゾーンとして、エコ運転ゾーンＺ１と、上側通常運転ゾーンＺ２と、下側通常運転ゾーンＺ３と、が設定されている。
エコ運転ゾーンＺ１は、ボイラ効率（ボイラ２０の熱効率）が第１閾値（例えば、９８％）よりも高くなる負荷率の範囲であり、エコ運転ポイントＥＰを含む。このエコ運転ゾーンＺ１は、ボイラ２０を燃焼させる上で、好ましい負荷率の範囲である。 In the present embodiment, the plurality of boilers 20 are set with eco-operating points EP, which is a load factor at which the boiler efficiency is highest, and are also set with a plurality of operation zones divided by a predetermined load factor range. Is done.
More specifically, in the present embodiment, an eco operation zone Z1, an upper normal operation zone Z2, and a lower normal operation zone Z3 are set as a plurality of operation zones.
The eco-operation zone Z1 is a load factor range in which the boiler efficiency (thermal efficiency of the boiler 20) is higher than a first threshold (for example, 98%), and includes an eco-operation point EP. This eco-operation zone Z1 is a preferable load factor range for burning the boiler 20.

上側通常運転ゾーンＺ２は、ボイラ効率が第１閾値よりも低くなる負荷率の範囲であってエコ運転ゾーンＺ１よりも負荷率の高い範囲に位置する。この上側運転ゾーンＺ２は、図２に示すように、ボイラ効率が第１閾値と、この第１閾値よりも低い第２閾値（例えば、９７％）との間となる負荷率の範囲である第１上側通常運転ゾーンＺ２１と、ボイラ効率が第２閾値よりも低くなる負荷率の範囲である第２上側通常運転ゾーンＺ２２と、を備える。 The upper normal operation zone Z2 is located in a load factor range in which the boiler efficiency is lower than the first threshold and in a range where the load factor is higher than the eco operation zone Z1. As shown in FIG. 2, the upper operation zone Z2 is a load factor range in which the boiler efficiency is between a first threshold value and a second threshold value (for example, 97%) lower than the first threshold value. 1 upper normal operation zone Z21 and 2nd upper normal operation zone Z22 which is the range of the load factor from which boiler efficiency becomes lower than a 2nd threshold value are provided.

下側通常運転ゾーンＺ３は、ボイラ効率が第１閾値よりも低くなる負荷率の範囲であってエコ運転ゾーンＺ１よりも負荷率の低い範囲に位置する。この下側通常運転ゾーンＺ３は、図２に示すように、ボイラ効率が第１閾値と第２閾値との間となる負荷率の範囲である第１下側通常運転ゾーンＺ３１と、ボイラ効率が第２閾値よりも低くなる負荷率の範囲である第２下側通常運転ゾーンＺ３２と、を備える。 The lower normal operation zone Z3 is located in a load factor range in which the boiler efficiency is lower than the first threshold and in a range where the load factor is lower than the eco operation zone Z1. As shown in FIG. 2, the lower normal operation zone Z <b> 3 includes a first lower normal operation zone Z <b> 31 in which the boiler efficiency is between the first threshold value and the second threshold value. A second lower normal operation zone Z32 that is a load factor range lower than the second threshold.

また、複数のボイラ２０には、それぞれ優先順位が設定されている。優先順位は、燃焼指示や燃焼停止指示を行うボイラ２０を選択するために用いられる。優先順位は、例えば整数値を用いて、数値が小さいほど優先順位が高くなるよう設定することができる。図２に示すように、ボイラ２０の１号機〜５号機のそれぞれに「１」〜「５」の優先順位が割り当てられている場合、１号機の優先順位が最も高く、５号機の優先順位が最も低い。この優先順位は、通常の場合、後述の制御部４の制御により、所定の時間間隔（例えば、２４時間間隔）で変更される。 Moreover, the priority order is set to each of the plurality of boilers 20. The priority order is used to select the boiler 20 that performs a combustion instruction or a combustion stop instruction. The priority order can be set, for example, using an integer value so that the lower the numerical value, the higher the priority order. As shown in FIG. 2, when the priorities of “1” to “5” are assigned to the first to fifth units of the boiler 20, the first unit has the highest priority, and the fifth unit has the highest priority. Lowest. In the normal case, this priority order is changed at predetermined time intervals (for example, 24 hour intervals) under the control of the control unit 4 described later.

以上説明したボイラ２０は、図１に示すように、燃焼が行われるボイラ本体２１と、ボイラ２０の燃焼状態を制御するローカル制御部２２と、を備える。
ローカル制御部２２は、要求負荷に応じてボイラ２０の燃焼状態を変更させる。具体的には、ローカル制御部２２は、信号線１６を介して台数制御装置３から送信される台数制御信号に基づいて、ボイラ２０の燃焼状態を制御する。
また、ローカル制御部２２は、台数制御装置３で用いられる信号を、信号線１６を介して台数制御装置３に送信する。台数制御装置３で用いられる信号としては、ボイラ２０の実際の燃焼状態、及びその他のデータが挙げられる。 The boiler 20 demonstrated above is provided with the boiler main body 21 in which combustion is performed, and the local control part 22 which controls the combustion state of the boiler 20, as shown in FIG.
The local control unit 22 changes the combustion state of the boiler 20 according to the required load. Specifically, the local control unit 22 controls the combustion state of the boiler 20 based on the number control signal transmitted from the number control device 3 via the signal line 16.
Further, the local control unit 22 transmits a signal used in the number control device 3 to the number control device 3 via the signal line 16. Examples of the signal used in the number control device 3 include an actual combustion state of the boiler 20 and other data.

次に、台数制御装置３の詳細について説明する。
台数制御装置３は、蒸気圧センサ７からの蒸気圧信号に基づいて、要求負荷に応じたボイラ群２の必要燃焼量、及び必要燃焼量に対応する各ボイラ２０の燃焼状態を算出し、各ボイラ２０（ローカル制御部２２）に台数制御信号を送信する。この台数制御装置３は、図１に示すように、記憶部５と、制御部４と、を備える。 Next, details of the number control device 3 will be described.
Based on the vapor pressure signal from the vapor pressure sensor 7, the number control device 3 calculates the required combustion amount of the boiler group 2 according to the required load and the combustion state of each boiler 20 corresponding to the required combustion amount, The number control signal is transmitted to the boiler 20 (local control unit 22). As shown in FIG. 1, the number control device 3 includes a storage unit 5 and a control unit 4.

記憶部５は、台数制御装置３（制御部４）の制御により各ボイラ２０に対して行われた指示の内容や、各ボイラ２０から受信した燃焼状態等の情報、複数のボイラ２０の運転ゾーンの設定に関する情報、複数のボイラ２０の燃焼パターンの設定条件等の情報、複数のボイラ２０の優先順位の設定の情報、優先順位の変更（ローテーション）に関する設定の情報等を記憶する。 The storage unit 5 includes information on instructions given to each boiler 20 under the control of the number control device 3 (control unit 4), information such as the combustion state received from each boiler 20, and operation zones of the plurality of boilers 20. , Information on setting conditions of combustion patterns of the plurality of boilers 20, information on setting priority of the plurality of boilers 20, information on setting on changing priority (rotation), and the like.

制御部４は、信号線１６を介して各ボイラ２０に各種の指示を行ったり、各ボイラ２０から各種のデータを受信したりして、５台のボイラ２０の燃焼状態や優先順位を制御する。各ボイラ２０は、台数制御装置３から燃焼状態の変更指示の信号を受けると、その指示に従って当該ボイラ２０を制御する。 The control unit 4 gives various instructions to each boiler 20 via the signal line 16 and receives various data from each boiler 20 to control the combustion state and priority order of the five boilers 20. . When each boiler 20 receives a signal for changing the combustion state from the number control device 3, it controls the boiler 20 according to the instruction.

ここで、本実施形態のボイラシステム１による複数のボイラ２０の燃焼状態の制御の詳細について説明する。図３〜図７は、それぞれ、本実施形態のボイラシステム１の動作の概略を示す図である。
本実施形態では、制御部４は、燃焼状態にあるボイラ２０のうちの少なくとも１台を負荷追従ボイラ２０Ａに設定し、その他のボイラ２０をエコ運転ボイラ２０Ｂに設定する。
負荷追従ボイラ２０Ａとは、要求負荷の変動に応じて負荷率を変更して燃焼させるボイラを示す。また、エコ運転ボイラ２０Ｂとは、要求負荷の変動の有無にかかわらず、エコ運転ゾーンＺ１の範囲の負荷率で燃焼させるボイラを示す。 Here, details of control of the combustion state of the plurality of boilers 20 by the boiler system 1 of the present embodiment will be described. 3-7 is a figure which shows the outline of operation | movement of the boiler system 1 of this embodiment, respectively.
In the present embodiment, the control unit 4 sets at least one of the boilers 20 in the combustion state as the load following boiler 20A, and sets the other boilers 20 as the eco-operation boiler 20B.
The load following boiler 20A refers to a boiler that changes the load factor in accordance with fluctuations in the required load and burns it. Further, the eco-operation boiler 20B indicates a boiler that burns at a load factor in the range of the eco-operation zone Z1 regardless of whether or not the required load varies.

尚、ボイラシステム１における負荷変動ボイラ２０Ａの台数は、予め規定値（例えば、１台）に設定してもよく、燃焼させるボイラ２０の台数に応じて設定してもよい。本実施形態では、燃焼させるボイラ２０のうち、優先順位の最も低いボイラ２０を負荷追従ボイラ２０Ａに設定した場合について説明する。 Note that the number of load fluctuation boilers 20A in the boiler system 1 may be set in advance to a specified value (for example, one) or may be set according to the number of boilers 20 to be burned. This embodiment demonstrates the case where the boiler 20 with the lowest priority among the boilers 20 to be burned is set as the load following boiler 20A.

例えば、図３に示すように、３台のボイラを燃焼させる場合、制御部４は、優先順位の最も低い３号機ボイラを負荷追従ボイラ２０Ａに設定し、その他のボイラである１号機ボイラ及び２号機ボイラをエコ運転ボイラ２０Ｂに設定する。そして、制御部４は、エコ運転ボイラ２０Ｂである１号機ボイラ及び２号機ボイラを、エコ運転ゾーンＺ１で燃焼させ、負荷追従ボイラ２０Ａである３号機ボイラの負荷率を要求負荷に応じて変更し、ボイラ群２の燃焼状態を調整する。
この場合、制御部４は、図３に示すように、エコ運転ボイラ２０Ｂを、エコ運転ポイントＥＰで燃焼させることが好ましい。 For example, as shown in FIG. 3, when three boilers are burned, the control unit 4 sets the No. 3 boiler with the lowest priority as the load following boiler 20 </ b> A, and the other No. 1 boilers and 2 boilers. Unit No. boiler is set to eco-operation boiler 20B. And the control part 4 burns the 1st machine boiler and 2nd machine boiler which are eco-operation boilers 20B in eco-operation zone Z1, and changes the load factor of the 3rd machine boiler which is 20A of load follow-up boilers according to request | requirement load. The combustion state of the boiler group 2 is adjusted.
In this case, as shown in FIG. 3, the control unit 4 preferably burns the eco-operation boiler 20B at the eco-operation point EP.

また、制御部４は、負荷追従ボイラ２０Ａの負荷率を、第１下側通常運転ゾーンＺ３１と第１上側通常運転ゾーンＺ２１との間の範囲で変更させてもよい。
この場合、制御部４は、負荷追従ボイラ２０Ａの負荷率が、第２上側通常運転ゾーンＺ２２に位置する場合に、燃焼させるボイラ２０の台数を増加させる。また、制御部４は、負荷追従ボイラ２０Ａの負荷率が、第２下側通常運転ゾーンＺ３２に位置する場合に、燃焼させるボイラ２０の台数を減少させる。 Further, the control unit 4 may change the load factor of the load following boiler 20A within a range between the first lower normal operation zone Z31 and the first upper normal operation zone Z21.
In this case, the control unit 4 increases the number of boilers 20 to be burned when the load factor of the load following boiler 20A is located in the second upper normal operation zone Z22. Further, the control unit 4 reduces the number of boilers 20 to be burned when the load factor of the load following boiler 20A is located in the second lower normal operation zone Z32.

具体的には、制御部４は、図４に示すように、負荷追従ボイラ２０Ａ（３号機ボイラ）の負荷率が第１上側通常運転ゾーンＺ２１の上限に到達する、つまり、第２上側通常運転ゾーンＺ２２の下限に到達すると、４号機ボイラの燃焼を開始させる。この場合、制御部４は、図５に示すように、３号機ボイラの設定をエコ運転ボイラ２０Ｂに変更してエコ運転ポイントＥＰで燃焼させ、新たに燃焼を開始した４号機ボイラを負荷追従ボイラ２０Ｂに設定する。 Specifically, as shown in FIG. 4, the control unit 4 determines that the load factor of the load following boiler 20A (No. 3 boiler) reaches the upper limit of the first upper normal operation zone Z21, that is, the second upper normal operation. When the lower limit of the zone Z22 is reached, combustion of the No. 4 boiler is started. In this case, as shown in FIG. 5, the control unit 4 changes the setting of the No. 3 boiler to the eco-operating boiler 20B and burns it at the eco-operating point EP, and the No. 4 boiler that has newly started combustion is a load following boiler. Set to 20B.

また、制御部４は、図６に示すように、負荷追従ボイラ２０Ａ（３号機ボイラ）の負荷率が第１下側通常運転ゾーンＺ３２の下限に到達する、つまり、第２下側通常運転ゾーンＺ３１の上限に到達すると、３号機ボイラの燃焼を停止させる。この場合、制御部４は、図７に示すように、２号機ボイラの設定を負荷追従運転ボイラ２０Ａに変更してこの２号機ボイラの負荷率を上昇させる。 Further, as shown in FIG. 6, the control unit 4 determines that the load factor of the load following boiler 20A (No. 3 boiler) reaches the lower limit of the first lower normal operation zone Z32, that is, the second lower normal operation zone. When the upper limit of Z31 is reached, the combustion of the No. 3 boiler is stopped. In this case, as shown in FIG. 7, the control unit 4 changes the setting of the No. 2 boiler to the load following operation boiler 20A and increases the load factor of the No. 2 boiler.

また、制御部４は、要求負荷が急激に変動した場合、負荷追従ボイラ２０Ａの負荷率を変動させると共に、エコ運転ボイラ２０Ｂの負荷率を、エコ運転ゾーンＺ１の範囲内で変動させてもよい。具体的には、単位時間あたりの要求負荷の変動量が、負荷追従ボイラ２０Ａの単位時間あたりの負荷率の最大変動量を上回った場合、制御部４は、負荷追従ボイラ２０Ａの負荷率を最大変動量分変動させると共に、エコ運転ボイラ２０Ｂの負荷率を、要求負荷の変動量と負荷追従ボイラ２０Ａの負荷率の最大変動量との差分変動させる。これにより、要求負荷が急激に変動した場合におけるボイラシステム１の負荷変動への追従性を向上させられる。
尚、この場合、制御部４は、エコ運転ボイラ２０Ｂが複数台あれば、すべてのエコ運転ボイラ２０Ｂが均等な負荷率となるように、負荷率を変動させる。 In addition, when the required load changes rapidly, the control unit 4 may change the load factor of the load following boiler 20A and may change the load factor of the eco-operation boiler 20B within the range of the eco-operation zone Z1. . Specifically, when the fluctuation amount of the required load per unit time exceeds the maximum fluctuation amount of the load factor per unit time of the load following boiler 20A, the control unit 4 maximizes the load factor of the load following boiler 20A. While varying the amount of variation, the load factor of the eco-operation boiler 20B is varied by a difference between the variation amount of the required load and the maximum variation amount of the load factor of the load following boiler 20A. Thereby, the followability to the load fluctuation of the boiler system 1 when a required load fluctuates rapidly can be improved.
In this case, if there are a plurality of eco-operation boilers 20B, the control unit 4 varies the load factor so that all the eco-operation boilers 20B have an equal load factor.

次に、本実施形態のボイラシステム１の動作を実現するための処理の流れについて、図８を参照して説明する。図８は、ボイラシステム１の処理の流れを示すフローチャートである。 Next, the flow of processing for realizing the operation of the boiler system 1 of the present embodiment will be described with reference to FIG. FIG. 8 is a flowchart showing a process flow of the boiler system 1.

初めに、処理の前準備として各ボイラ２０に対して負荷追従ボイラ２０Ａの台数の設定（ステップＳＴ１）及び運転ゾーンの設定（ステップＳＴ２）を行い、記憶部５の所定の領域に記憶する。 First, the number of load following boilers 20A is set for each boiler 20 as a preparation for processing (step ST1) and the operation zone is set (step ST2), and stored in a predetermined area of the storage unit 5.

次いで、ステップＳＴ３において、制御部４は、負荷追従ボイラ２０Ａの負荷率が第２上側通常運転ゾーンＺ２２に位置するかを判定する。負荷追従ボイラ２０Ａの負荷率が第２上側通常運転ゾーンＺ２２に位置すると判定された場合、処理は、ステップＳＴ４に進む。負荷追従ボイラ２０Ａの負荷率が第２上側通常運転ゾーンＺ２２に位置しないと判定された場合、処理は、ステップＳＴ６に進む。 Next, in step ST3, the control unit 4 determines whether the load factor of the load following boiler 20A is located in the second upper normal operation zone Z22. When it is determined that the load factor of the load following boiler 20A is located in the second upper normal operation zone Z22, the process proceeds to step ST4. When it is determined that the load factor of the load following boiler 20A is not located in the second upper normal operation zone Z22, the process proceeds to step ST6.

ステップＳＴ４において、制御部４は、燃焼させるボイラを１台増加させ、処理は、ステップＳＴ５に進む。
ステップＳＴ５において、制御部４は、これまで負荷追従ボイラ２０Ａであったボイラをエコ運転ボイラ２０Ｂに設定してこのボイラをエコ運転ポイントＥＰで燃焼させると共に、新たに燃焼を開始したボイラを負荷追従ボイラ２０Ａに設定し、処理は終了する。 In step ST4, the control unit 4 increases one boiler to be burned, and the process proceeds to step ST5.
In step ST5, the control unit 4 sets the boiler that has been the load following boiler 20A as the eco operation boiler 20B and burns the boiler at the eco operation point EP, and loads the boiler that has newly started combustion. The boiler 20A is set and the process ends.

ステップＳＴ３において、制御部４により負荷追従ボイラ２０Ａの負荷率が第２上側通常運転ゾーンＺ２２に位置しないと判定された場合、ステップＳＴ６において、制御部４は、負荷追従ボイラ２０Ａの負荷率が第２下側通常運転ゾーンＺ３２に位置するかを判定する。負荷追従ボイラ２０Ａの負荷率が第２下側通常運転ゾーンＺ３２に位置すると判定された場合、処理は、ステップＳＴ７に進む。負荷追従ボイラ２０Ａの負荷率が第２下側通常運転ゾーンＺ３２に位置しないと判定された場合、処理は、ステップＳＴ３に戻る。 In step ST3, when the control unit 4 determines that the load factor of the load following boiler 20A is not located in the second upper normal operation zone Z22, in step ST6, the control unit 4 determines that the load factor of the load following boiler 20A is the first. 2. It is determined whether it is located in the lower normal operation zone Z32. When it is determined that the load factor of the load following boiler 20A is located in the second lower normal operation zone Z32, the process proceeds to step ST7. When it is determined that the load factor of the load following boiler 20A is not located in the second lower normal operation zone Z32, the process returns to step ST3.

ステップＳＴ７において、制御部４は、燃焼させるボイラを一台減少させ、処理は、ステップＳＴ８に進む。
ステップＳＴ８において、制御部４は、負荷追従ボイラ２０Ａの燃焼を停止すると共に、燃焼しているボイラのうち最も優先順位の低いボイラの設定をエコ運転ボイラ２０Ｂから負荷追従ボイラ２０Ａに変更して、この負荷追従ボイラ２０Ａの負荷率を増加させ、処理は終了する。 In step ST7, the control unit 4 decreases the number of boilers to be burned, and the process proceeds to step ST8.
In step ST8, the control unit 4 stops the combustion of the load following boiler 20A, changes the setting of the lowest priority boiler among the burning boilers from the eco-operation boiler 20B to the load following boiler 20A, The load factor of the load follower boiler 20A is increased, and the process ends.

以上説明した本実施形態のボイラシステム１によれば、以下のような効果を奏する。 According to the boiler system 1 of this embodiment demonstrated above, there exist the following effects.

（１）複数のボイラ２０を、エコ運転ゾーンＺ１、上側通常運転ゾーンＺ２、及び下側通常運転ゾーンＺ３に区分し、制御部４に、燃焼状態にあるボイラ２０のうちの少なくとも１台を負荷追従ボイラ２０Ａに設定させ、この負荷追従ボイラ２０Ａ以外のボイラを、エコ運転ゾーンＺ１で燃焼させるエコ運転ボイラ２０Ｂに設定させた。これにより、要求負荷が変動した場合に、エコ運転ボイラ２０Ｂをエコ運転ゾーンＺ１で燃焼させつつ、負荷追従ボイラ２０Ａの負荷率を変動させることで、ボイラ群２による出力蒸気量を要求負荷の変動に追従させられる。よって、要求負荷の変動があった場合に複数台のボイラ２０の燃焼状態が頻繁に変更されないので、出力される蒸気量の安定性を高めつつボイラ効率を高く保てる。 (1) A plurality of boilers 20 are divided into an eco-operation zone Z1, an upper normal operation zone Z2, and a lower normal operation zone Z3, and the control unit 4 is loaded with at least one of the boilers 20 in a combustion state. The follower boiler 20A was set, and the boilers other than the load follower boiler 20A were set to the eco-operation boiler 20B for burning in the eco-operation zone Z1. As a result, when the required load fluctuates, the output steam amount of the boiler group 2 is changed in the required load by changing the load factor of the load following boiler 20A while burning the eco-operation boiler 20B in the eco-operation zone Z1. It is made to follow. Therefore, when the required load fluctuates, the combustion state of the plurality of boilers 20 is not frequently changed, so that the boiler efficiency can be kept high while improving the stability of the output steam amount.

（２）制御部４に、エコ運転ボイラ２０Ｂをエコ運転ポイントＥＰで燃焼させた。これにより、エコ運転ボイラ２０Ｂを最もボイラ効率のよい状態で燃焼させられるので、ボイラシステム１のボイラ効率をより向上させられる。 (2) The eco-driving boiler 20B was burned at the eco-driving point EP in the control unit 4. Thereby, since the eco-operation boiler 20B can be burned in a state with the best boiler efficiency, the boiler efficiency of the boiler system 1 can be further improved.

（３）上側通常運転ゾーンＺ２を、第１上側通常運転ゾーンＺ２１と、第２上側通常運転ゾーンＺ２２と、を含んで構成し、下側通常運転ゾーンＺ３を、第１下側通常運転ゾーンＺ３１と、第２下側通常運転ゾーンＺ３２と、を含んで構成した。そして、制御部４に、負荷追従ボイラ２０Ａの負荷率が第２上側通常運転ゾーンＺ２２に位置する場合に、燃焼させるボイラ２０の台数を増加させ、負荷追従ボイラ２０Ａの負荷率が第２下側通常運転ゾーンＺ３２に位置する場合に燃焼させるボイラ２０の台数を減少させた。これにより、負荷追従ボイラ２０Ａがボイラ効率の低い状態で燃焼する場合に、燃焼させるボイラの台数を増加又は減少させることで、よりボイラ効率の高い状態で複数のボイラ２０を燃焼させられる。よって、ボイラシステム１のボイラ効率を更に向上させられる。 (3) The upper normal operation zone Z2 includes the first upper normal operation zone Z21 and the second upper normal operation zone Z22, and the lower normal operation zone Z3 is defined as the first lower normal operation zone Z31. And the second lower normal operation zone Z32. Then, when the load factor of the load following boiler 20A is positioned in the second upper normal operation zone Z22, the controller 4 increases the number of boilers 20 to be burned, and the load factor of the load following boiler 20A is reduced to the second lower side. The number of boilers 20 to be burned when located in the normal operation zone Z32 was reduced. Thereby, when the load following boiler 20A burns in a state where the boiler efficiency is low, the plurality of boilers 20 can be burned in a state where the boiler efficiency is higher by increasing or decreasing the number of boilers to be burned. Therefore, the boiler efficiency of the boiler system 1 can be further improved.

以上、本発明のボイラシステムの好ましい一実施形態につき説明したが、本発明は、上述の実施形態に制限されるものではなく、適宜変更が可能である。
例えば、本実施形態では、ボイラ２０を、５つの運転ゾーンに区分したが、これに限らない。即ち、ボイラは、少なくともエコ運転ゾーン、上側通常運転ゾーン及び下側通常運転ゾーンの３つの運転ゾーンに区分されていればよく、ボイラを６つ以上の運転ゾーンに区分してもよい。 The preferred embodiment of the boiler system of the present invention has been described above, but the present invention is not limited to the above-described embodiment, and can be modified as appropriate.
For example, in this embodiment, although the boiler 20 was divided into five operation zones, it is not restricted to this. In other words, the boiler only needs to be divided into at least three operation zones of an eco-operation zone, an upper normal operation zone, and a lower normal operation zone, and the boiler may be divided into six or more operation zones.

また、本実施形態では、本発明を、５台のボイラ２０からなるボイラ群２を備えるボイラシステム１に適用したが、これに限らない。即ち、本発明を、６台以上のボイラからなるボイラ群を備えるボイラシステムに適用してもよく、また、２台のボイラからなるボイラ群を備えるボイラシステムに適用してもよい。 Moreover, in this embodiment, although this invention was applied to the boiler system 1 provided with the boiler group 2 which consists of the five boilers 20, it is not restricted to this. That is, the present invention may be applied to a boiler system including a boiler group including six or more boilers, or may be applied to a boiler system including a boiler group including two boilers.

また、本実施形態では、ボイラ２０を、燃焼停止状態Ｓ０と最小燃焼状態Ｓ１との間の燃焼状態の変更をボイラ２０の燃焼をオン／オフすることで制御し、最小燃焼状態Ｓ１から最大燃焼状態Ｓ２の範囲においては燃焼量を連続的に制御可能な比例制御ボイラ２０により構成したが、これに限らない。即ち、ボイラを、燃焼停止状態から最大燃焼状態の範囲すべてにおいて、燃焼量を連続的に制御可能な比例制御ボイラにより構成してもよい。 Further, in the present embodiment, the boiler 20 is controlled by changing the combustion state between the combustion stop state S0 and the minimum combustion state S1 by turning on / off the combustion of the boiler 20, and the maximum combustion from the minimum combustion state S1. In the range of state S2, although comprised with the proportional control boiler 20 which can control a combustion amount continuously, it is not restricted to this. That is, the boiler may be configured by a proportional control boiler that can continuously control the combustion amount in the entire range from the combustion stop state to the maximum combustion state.

１ボイラシステム
２ボイラ群
４制御部
２０ボイラ
Ｒ_ｍｉｎ最小負荷率
Ｚ１エコ運転ゾーン
Ｚ２上側通常運転ゾーン
Ｚ３下側通常運転ゾーン
Ｚ２１第１上側通常運転ゾーン
Ｚ２２第２上側通常運転ゾーン
Ｚ３１第１下側通常運転ゾーン
Ｚ３２第２下側通常運転ゾーン
ＥＰエコ運転ポイント DESCRIPTION OF SYMBOLS 1 Boiler system 2 Boiler group 4 Control part 20 Boiler _Rmin Minimum load factor Z1 Eco-operation zone Z2 Upper normal operation zone Z3 Lower normal operation zone Z21 First upper normal operation zone Z22 Second upper normal operation zone Z31 First lower side Normal operation zone Z32 Second lower normal operation zone EP Eco operation point

Claims

A boiler system comprising a boiler group including a plurality of boilers capable of burning by continuously changing a load factor, and a control unit that controls a combustion state of the boiler group according to a required load,
In the plurality of boilers,
Eco-driving point, which is the load factor that gives the highest boiler efficiency,
An eco-operation zone that is a load factor range in which the boiler efficiency is higher than the first threshold and includes the eco-operation point; and
An upper normal operation zone located in a range of a load factor in which the boiler efficiency is lower than the first threshold and a load factor higher than the eco-operation zone;
A lower normal operation zone located in a load factor range in which the boiler efficiency is lower than the first threshold value and in a range where the load factor is lower than the eco-operation zone, is set,
The controller is
At least one of the boilers in a combustion state is burned in a range between the lower limit of the lower normal operation zone and the upper limit of the upper normal operation zone by changing a load factor according to a change in required load. A boiler system that is set as a load following boiler and is set as an eco-operation boiler that burns boilers other than the load-following boiler in the eco-operation zone.

The boiler system according to claim 1, wherein the control unit burns the eco-operation boiler at the eco-operation point.

The upper normal operation zone is
A first upper normal operation zone that is a load factor range in which the boiler efficiency is between the first threshold and a second threshold lower than the first threshold;
A second upper normal operation zone that is a load factor range in which the boiler efficiency is lower than the second threshold,
The lower normal operation zone is
A first lower normal operation zone which is a load factor range in which the boiler efficiency is between the first threshold and a second threshold lower than the first threshold;
A second lower normal operation zone that is a load factor range in which the boiler efficiency is lower than the second threshold,
The controller is
When the load factor of the load following boiler is located in the second upper normal operation zone, increase the number of boilers to be burned,
The boiler system according to claim 1 or 2, wherein the number of boilers to be burned is reduced when a load factor of the load following boiler is located in the second lower normal operation zone.