JP3650839B2 - Fluidized bed apparatus Fluctuating load measuring method and apparatus for inner pipe - Google Patents

Description

ここに、添字Ｔはベクトルあるいはマトリクスの転置を意味する。
【０００７】
［Ｍ］，［Ｃ］，［Ｋ］及び｛Ｑ（ｔ）｝を用いれば、動荷重が作用した場合の伝熱管の振動方程式は次の数式（２）
【数２】

となる。｛Ｕ（ｔ）｝は図１３中の各質点の鉛直方向の変位ベクトルであり、ベクトル成分ｕ₁（ｔ）〜ｕ₈（ｔ）を用いて、次の数式（３）で表される。
【数３】

数式（２）中の

を表す。
【０００８】
確率論的振動解析手法に基づけば、伝熱管の変形量評価式は以下の数式（４）に導出される。
【数４】

【０００９】
ここに、ｕ_i，_rmsは図１３に示す伝熱管モデルの質点ｉの変位のroot mean square値（以下、実効値と称す）である。Ｓ_Q，_ev（ω）はｅ番目の質点（以下、質点ｅと言う）に働く変動荷重Ｑ_e（ｔ）のパワースペクトル、Ｓ_Q，_vv（ω）はｖ番目の質点（以下、質点ｖと言う）に働く変動荷重Ｑ_v（ｔ）のパワースペクトル、Ｗ_Q，_ev（ω）は質点ｅに働くＱ_e（ｔ）と質点ｖに働くＱ_v（ｔ）のコヒーレンススペクトル、θ_Q，_ev（ω）はＱ_e（ｔ）とＱ_v（ｔ）の位相スペクトルである。ｎは質点の数（＝８）、ｍは固有モード数であり、φ_ijは［Ｍ］で正規化したｊ次固有モードベクトルの節点ｉの成分である。
【００１０】
Ｈ_j（ω）はｊ次固有モードの周波数応答関数であり、図１３に示す管モデルと同じ管軸方向長さを持つ管のｊ次のモードの減衰比β_i、固有円振動数ω_j、変動荷重の周波数ω及び虚数γを用いて次の数式（５）に従って計算できる。
【数５】

【００１１】
数式（５）により計算したＨ_j（ω）を数式（４）に入力し、さらに変動荷重のパワースペクトルＳ_Q，_ee（ω）及びＳ_Q，_vv（ω）、コヒーレンススペクトルＷ_Q，_ev（ω）、位相スペクトルθ_Q，_ev（ω）を式（４）に入力すればｕ_i，_rmsが計算できる。
【００１２】
以上より、図１３に示す伝熱管の管軸方向に分布して作用する変動荷重のパワースペクトルＳ_Q，_ev（ω）、コヒーレンススペクトルＷ_Q，_ev（ω）、位相スペクトルθ_Q，_ev（ω）等の変動荷重のランダム性を表す物理量が測定できれば、数式（４）により厳密な伝熱管変形量の評価が可能であることがわかる。
【００１３】
ところが、従来の変動荷重測定方法では、上記のような、管軸方向の動荷重のパワースペクトル、コヒーレンススペクトル及び位相スペクトルを測定できなかった。従来の測定方法を図１４及び図１５に示す。これら二つの図はElectric Power Research Instituteのプロジェクトの研究成果報告書（プロジェクト番号：７１８−２、報告期日：１９８０年９月、報告書タイトル：A Study of Forces on Immersed Tubes in Fluidized Beds、著者：T.C.Kennedy, Oregon State University）から抜粋したものである。
【００１４】
図１４と図１５について詳しく説明する。図１４は、ダミー管１１（固定端部のみ図示）全体に作用する変動荷重を測定する装置を示している。この装置は、中空のダミー管１１の内部に円板１３を固定し、この円板１３を支持管１４及び支持板１７を介して支持フレーム１２にリベット１８で接合したものであり、支持管１４にはひずみゲージ１５が貼付けられている。このような構造にすることにより、ダミー管１１に流動媒体が衝突してダミー管が振動した場合、この振動が支持管１４に伝播して、ひずみゲージ１５により、この振動が測定できる。測定したひずみは容易に荷重に換算でき、ダミー管１１の管軸方向全域に作用する変動荷重が測定できる仕組みになっている。
【００１５】
図１５は第２の従来例であり、ダミー管２１全体に作用する変動荷重を測定する装置を示している。この装置は、ダミー管２１をＵボルト２３で支持板２４に固定し、この支持板２４を支持具２５を介して支持フレーム２２に接合したものであり、支持板２４にはひずみゲージ１５が貼付られている。このような構造にすることにより、図１４と同様に、ダミー管２１の管軸方向全域に作用する変動荷重が測定される。
【００１６】
【発明が解決しようとする課題】
しかし、上述したように図１４または図１５に示した測定装置では、ダミー管１１、２１の管軸方向全域に作用する変動荷重はマクロ的に測定できるが、変動荷重の管軸方向の分布の他、相関性や位相等のランダム性は測定不可能であり、ひいては数式（４）による高精度な伝熱管変形量評価ができなかった。
【００１７】
また、このような理由により、従来においては、図１２に示すような変動荷重（Ｑ_i，Ｑ_j等）について、図１６に示すようなＱ_i，Ｑ_j間の相関や位相θ_ij等のランダム性を全く考慮せず、変動荷重（Ｑ_i，Ｑ_j等）の値を単純加算して伝熱管に負荷するという方法を採っていた。この方法では明らかに伝熱管の変形量を過大評価することになり、伝熱管断面及び管群支持構造の設計は非常に不合理に行ならざるを得ないことが問題であった。
【００１８】
本発明の課題は上記従来技術における欠点を解消し、下記の技術的課題を解決することである。
（１）流動層装置層内管の変形量評価式に必要な、変動荷重の時間的及び空間的な分布やランダム性を高精度に測定できる方法並びに装置を提供する。
（２）前記（１）により測定した変動荷重のランダム性を用いて、高精度に流動層装置層内管の変形量を評価することを可能にする。
【００１９】
【課題を解決するための手段】
上記課題は、次の構成によって解決される。
すなわち、層内に管群を有する流動層装置の中のある選ばれた層内管または該管を模擬したダミー管にひずみゲージを貼り付け、流動媒体の衝突によって管に発生する変動荷重を測定する方法において、層内管またはダミー管を管軸方向に少なくとも二つ以上に分割し、分割した各管のひずみを測定することにより、流動媒体による変動荷重の時間的または空間的な分布やランダム性を測定する流動層装置層内管の変動荷重測定方法である。
【００２０】
本発明は上述したように流動媒体による変動荷重の測定を対象とする管を、管軸方向に複数に分割することにより、分割したある一つの管に流動媒体が衝突して荷重が生じても、この荷重が他の分割した管に伝播することがない。これにより、管軸方向における変動荷重の分布の他、変動荷重管間の相関性や位相等のランダム性が測定できる。
【００２１】
ここで、管軸方向に少なくとも二つ以上に分割した各管の間での力の伝達が絶縁されるように、分割した管の周囲に配置される支持管によって、分割した各管を個々に支持することにより、より正確に管軸方向における変動荷重を測定できる。
【００２２】
本発明には次の構成も含まれる。
すなわち、層内に管群を有する流動層装置の中のある選ばれた層内管または該管を模擬したダミー管にひずみゲージを貼り付け、流動媒体の衝突によって管に発生する変動荷重を測定する装置において、層内管またはダミー管を管軸方向に少なくとも二つ以上に分割し、分割した各管に少なくとも一枚以上のひずみゲージを貼り付けて流動媒体による変動荷重を測定する流動層装置層内管の変動荷重測定装置である。
【００２３】
上記流動層装置層内管の変動荷重測定装置は、管軸方向に少なくとも二つ以上に分割した管の間での力の伝達が絶縁されるように、分割した管の周囲に配置される支持管によって、分割した管を個々に支持する構成を採用しても良い。また、上記変動荷重測定装置は流動層装置のケーシングに菱形の穴を開け、該穴に挿入できて、取り外しが可能な構成とすることもできる。
【００２４】
菱形の支持板に両端を支持された変動荷重測定装置を前記ケーシングに菱形の穴に装着して、変動荷重測定装置を流動層装置の管群に挿入すると、変動荷重測定装置は管群の管の配置ピッチを乱すことがなく、流動層装置における流動層の流動状態を阻害することがない。
【００２５】
本発明の測定方法及び装置が適用される流動層装置の層内に配置される管は伝熱管、反応管等など、ガスまたは水などの加熱用、各種反応用の配管として用いられる熱回収用管、あるいは流動層内の冷却用などに用いられる層内温度制御用の配管などである。前記熱回収用流動層装置とは、流動層ボイラ、蒸気ボイラの蒸気を非腐食性ガスで過熱するスーパーヒータ、一般的なプロセスガスの加熱管、反応性ガスの反応管などである。また、前記層内温度制御用流動層装置とは、ごみ焼却炉など層内温度を調節する伝熱管などである。
【００２６】
【発明の実施の形態】
本発明の実施の形態について説明する。
図１に本発明の一実施例の概略側面図を示す。本実施例では、管軸方向に分割した測定対象管２０１〜２０８にひずみゲージ１５をそれぞれ貼り付けて、管２０１〜２０８が鉛直方向にたわんだ場合のひずみ２０１Ｚ〜２０８Ｚを測定するものであり、これによって、管軸方向の変動荷重の分布の他、相関性、位相等のランダム性が評価可能である。
【００２７】
図１に示す装置は、ひずみゲージ１５、測定対象管２０１〜２０８等の部品が焼損しない運転状態（例えば、コールド運転状態）においては、事業用、産業用等の目的で実際に使用される流動層装置及び試験に使用される装置のどちらにも支障なく使える。以下、両者を「流動層装置」と総称して、本実施例を説明する。
【００２８】
図１中のＡ−Ａ線断面、Ｂ−Ｂ線断面及びＣ−Ｃ線断面を、各々図２、図３及び図４に示す。これらの三つの図２〜図４の内、まず最初に図３を説明し、続いて図２、図４の順に説明する。
【００２９】
図３は、図１におけるひずみゲージ１５の貼り付けられた測定対象管２０１〜２０８のうち、管２０３の断面を示したものである。測定対象管２０３は、該管２０３の両端部をＴ型の支持板２１０を介して分割しない管２１２、２１３、２１４に支持されている。
【００３０】
図２は、図１及び図３に示した支持管２１２、２１３、２１４の端部の断面を示したものである。図２から支持管２１２、２１３、２１４の端部は支持板２１５に接合されていることがわかる。また、図１に示すように管２１２、２１３、２１４のもう一方の端部は、支持板２１６に支持されている。なお、支持板２１５、２１６には、管ピッチを変えない目的で管２１１も接合されている。
【００３１】
図４は、図１におけるひずみのゲージ１５の貼り付けられた測定対象管２０１〜２０８のうち、管２０３の右端部から管２０４の左端部までの距離の中央点での断面を示したものである。図４に示すように、図１のＣ−Ｃ線断面には、４つの支持管２１１〜２１４しか存在せず、測定対象管２０３と管２０４が連続していないことが分かる。
【００３２】
図１に示す測定対象管２０１〜２０８は、塩化ビニール樹脂等の変形しやすい低剛性な材料を用いて作製し、支持管２１１、２１２、２１３、２１４及び支持板２１０、２１５、２１６は、鉄等の変形しにくい高剛性な材料を用いて作製すればよい。
【００３３】
ひずみゲージ１５からひずみ測定計器（図示せず）の間はリード線（図示せず）で連結する必要があるが、このような配線は支持管２１１、２１２、２１３、２１４を這わせて図２中の支持板２１５に設けられた配線取り出し口２１７から取り出せるようになっている。
【００３４】
本実施例は上記のような構造であることから、測定対象管２０１〜２０８の間での力の伝達が絶縁され、個々の測定対象管２０１〜２０８に作用する変動荷重の管軸方向の分布の他、相関性や位相等を定量的に評価できる。以下、図１に示した装置のことを「管軸方向動荷重分布測定装置」と称す。
【００３５】
次に、前記管軸方向動荷重分布測定装置を流動層装置に設置する方法を説明する。図５に管軸方向から見た流動層装置を示す。管群９はケーシング１０６に固定され、装置の運転時には、管群９が流動媒体に埋没する状態になる。このような装置の任意の位置に、管軸方向動荷重分布測定装置を設置することができる。設置の方法は以下に述べる通りである。
【００３６】
図２（図１のＡ−Ａ線断面図）に示すように、管軸方向動荷重分布測定装置の支持板２１５は菱形になっている。支持板２１５を菱形にする理由は菱形の支持板２１５を有する管軸方向動荷重分布測定装置を図５の流動層装置の管群９に挿入すると、管群９の管の配置ピッチを乱すことがなく、ひいては図５の流動層装置における流動状態を阻害することがないためである。
【００３７】
支持板２１５の具体的な設置方法としては、図１中の菱形の支持板２１５に対応するように図５の装置のケージング１０６に穴２１５ａ〜２１５ｉを開け、その位置に管軸方向動荷重分布測定装置を挿入できる。このような構造にすることによって、装置における任意の場所（穴２１５ａ〜２１５ｉ等）の流動媒体変動荷重を測定することができる。
【００３８】
なお、本発明では、管軸方向動荷重分布測定装置を挿入する穴２１５ａ〜２１５ｉの個数の位置について特に限定はない。また、本発明では前述した測定対象管２０１〜２０８に貼り付けるひずみゲージ１５の枚数や位置の他、支持板２１５、２１６や支持管２１１、２１２、２１３、２１４等の部品の材質についても特に限定されるものではない。
【００３９】
図１に示す管軸方向動荷重分布測定装置を用いて、上記したひずみ２０１Ｚ〜２０８Ｚの時刻歴波形、周波数スペクトル等を測定した例を以下に示す。本測定例では、図１に示す測定装置を図５に示す流動層装置中の穴２１５ｈに設置した。装置の運転条件として、空気分散板３から吹き上げた空気により、ケーシング１０６内部に充填された流動媒体を管群９の上端まで上昇させた流動状態で、ひずみ測定を実施した。ひずみの時刻歴波形の測定時間は約１５分、測定対象としたひずみの周波数帯域は０〜１６Ｈｚ、スペクトルの平均回数は３２とした。
【００４０】
なお、以下では、分かり易くするため、図１に示す管軸方向動荷重分布測定装置を図６のように模式的に描いたものを説明に用いる。
図７に、管軸方向動荷重分布測定装置（図６）で測定したひずみ２０１Ｚ〜２０８Ｚのうち、ひずみ２０１Ｚ〜２０４Ｚの時刻歴波形を示す。これらの時刻歴波形に着目すると、ひずみ２０１Ｚ〜２０４Ｚの波形の高さがほぼ等しいこと、ひずみ２０１Ｚ〜２０４Ｚの波形の凹凸形状が時間軸に対してほぼ一致していることから、ひずみ２０１Ｚ〜２０４Ｚはほぼ同振幅、同位相で振動していることが窺える。
【００４１】
図８に、図７に示したひずみ２０１Ｚ〜２０４Ｚのパワースペクトルを示す。図８より、ひずみ２０１Ｚ〜２０４Ｚのパワースペクトルは約３Ｈｚを中心として２〜４Ｈｚの周波数帯域のひずみ成分が卓越している。装置における流動状態を観察した結果、流動媒体を含んだ気泡が伝熱管に衝突する頻度は１秒あたり約３回であったことから、本測定例で観測されたひずみは、図１１に示す流動媒体５を含んだ気泡２の衝突によるものであるといえる。
【００４２】
図９に本実施例での測定例によるコヒーレンススペクトルを示す。前述したように、図８に示すひずみのパワースペクトルでは２〜４Ｈｚの周波数帯域成分が卓越しているが、図９によるとコヒーレンススペクトルでも２〜４Ｈｚの周波数帯域成分が大きい。管２０１を基準点として管軸方向距離とコヒーレンスの関係を検討した結果、管２０１から距離が近い管２０２では管２０１に対する相関性が高いが、管２０１からの距離が長くなるにしたがって管２０３、２０４の順で相関性は徐々に低くなっている。
【００４３】
図１０に、ひずみ２０１Ｚ〜２０４Ｚの位相スペクトルを示す。ひずみのパワースペクトルは約３Ｈｚを中心として２〜４Ｈｚの周波数帯域成分が卓越しており、かつこの帯域においてコヒーレンススペクトルの値が大きいので、本実施例では位相スペクトルの周波数が３Ｈｚの点の位相値に着目した。これによると基準点である管２０１からの距離にかかわらず、ひずみ２０１Ｚに対する管２０１〜２０４のひずみ２０２Ｚ、２０３Ｚ及び２０４Ｚはほぼ同位相であり、管２０１〜２０４には同じ方向のひずみが発生していることが分かった。
【００４４】
【発明の効果】
本発明によれば、以下の事項が実現される。
（１）流動層装置において、流動媒体の衝突によって管群に生じる変動荷重の時間的空間的な分布やランダム性の測定が可能となる。
（２）前記（１）によって測定されたランダム性を考慮することにより、高精度かつ合理的な伝熱管の変形量評価が可能となる。
【００４５】
（３）前記（２）で述べた高精度かつ合理的な伝熱管の変形量評価に基づき、流動層装置の層内伝熱管群及び管群支持構造の信頼性評価が可能となる。
（４）前記（３）による信頼性評価の結果に基づいて流動層装置の運転状態を制御することにより、装置自体に損傷を与えることがなく、安定した流動層装置の運用が可能となる。
【図面の簡単な説明】
【図１】 本発明による変動荷重測定装置の一実施例を示した図である。
【図２】 図１の変動荷重測定装置のＡ−Ａ線断面図である。
【図３】 図１の変動荷重測定装置のＢ−Ｂ線断面図である。
【図４】 図１の変動荷重測定装置のＣ−Ｃ線断面図である。
【図５】 図１の変動荷重測定装置を流動層中に配置した流動層断面図である。
【図６】 図１に示す変動荷重測定装置の模式図である。
【図７】 本発明特有の効果の一例として、ひずみの時刻歴波形とパワースペクトルを示したものである。
【図８】 本発明特有の効果の一例として、ひずみの時刻歴波形とパワースペクトルを示したものである。
【図９】 本発明特有の効果の一例として、ひずみのコヒーレンススペクトル及び位相スペクトルを示したものである。
【図１０】 本発明特有の効果の一例として、ひずみのコヒーレンススペクトル及び位相スペクトルを示したものである。
【図１１】 本発明の変動荷重測定装置が適用される流動層ボイラの模式図である。
【図１２】 伝熱管の管軸方向に作用する変動荷重と伝熱管の変形量の関係を示した図である。
【図１３】 管の集中質点モデルを示したものである。
【図１４】 従来の変動荷重測定装置を示したものである。
【図１５】 従来の変動荷重測定装置を示したものである。
【図１６】 伝熱管の変形量評価手法の概要を示したものである。
【符号の説明】
３ 空気分散板 ９ 管群
１５ ひずみゲージ １０６ ケーシング
２０１〜２０８ 測定対象管 ２０１Ｚ〜２０８Ｚ ひずみ
２１２〜２１４ 非分割支持管 ２１０、２１５、２１６ 支持板
２１１ 支持管 ２１７ 配線取り出し口[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fluidized bed apparatus used for all purposes such as improvement of heat exchange performance and reaction promotion, and in particular, distribution and randomness of fluctuating load of fluidized media colliding with heat transfer tubes and reaction tubes in the layer. The present invention relates to a method and an apparatus for enabling quantitative measurement.
[0002]
[Prior art]
Fluidized bed apparatuses are generally widely used for all purposes such as improving heat exchange performance and promoting reaction. As an example, in the field of thermal power plants, fluidized bed boilers are attracting attention in order to reduce CO ₂ emissions and fuel consumption. This type of boiler is characterized in that heat transfer efficiency is good because coal, which is fuel, is mixed with a fluid medium that is granular solid and burned.
[0003]
FIG. 11 shows a schematic diagram of a fluidized bed boiler. A heat transfer tube 1 is installed in the furnace 6 and is filled with a fluid medium 5. The fluid medium 5 is fluidized by hot air blown through a blower (not shown), the wind box 4 and the air dispersion plate 3, and when the bubbles 2 containing the fluid medium 5 collide with the heat transfer tube 1. A fluctuating load acts on the heat transfer tube 1. This fluctuating load is random in time and space, but when this fluctuating load repeatedly acts on the heat transfer tube 1, repeated stress is generated in the heat transfer tube 1 which is the heart of the fluidized bed boiler and its support structure. To do. Therefore, in order to evaluate the safety against fatigue of the heat transfer tube 1 and its supporting structure, and to obtain a highly reliable structure based on this evaluation, the deformation amount of the heat transfer tube 1 is determined in consideration of the randomness of the fluctuating load. Precise estimation is an important issue.
[0004]
FIG. 12 shows a state in which random variable loads (Q _i , Q _j, etc.) due to the fluid medium act on the heat transfer tube 1. To strictly evaluate the deformation amount (u _i , u _j, etc.) of the heat transfer tube 1, the distribution of the fluctuating load (Q _i , Q _j, etc.) in the axial direction, the correlation between the fluctuating loads and the randomness such as the phase It is necessary to measure the data representing Specifically, the required data includes the power spectrum that shows the square value of the fluctuating load for each frequency band component, the coherence spectrum that shows the correlation between fluctuating loads for each frequency band component, and the phase between the fluctuating loads in the frequency band. There is a frequency spectrum such as a phase spectrum shown for each component, and it is necessary to incorporate these spectra into the evaluation of the deformation amount of the heat transfer tube. This evaluation method will be specifically described below.
[0005]
In order to calculate the deformation amount of the heat transfer tube, a calculation model (concentrated mass point model) as shown in FIG. 13 is required. In FIG. 13, the number of mass points is 8 (m _{1 to} m ₈ ), but this number is the same as the number of strain measurement target tubes 201 to 208 in the dynamic load measuring apparatus (FIG. 1) according to the present invention described later. It corresponds.
[0006]
In this model, rigidity k ₁ to k ₈ and damping constants c _{1 to} c ₈ are set corresponding to the mass points, and dynamic loads Q ₁ (t) to Q ₈ (t) as external forces act on each mass point. . In this model, the mass matrix is [M], the stiffness matrix [K], the damping matrix is [C], and the dynamic load vector acting on each mass point is expressed by the following equation (1).
[Expression 1]

Here, the subscript T means transposition of a vector or a matrix.
[0007]
If [M], [C], [K] and {Q (t)} are used, the vibration equation of the heat transfer tube when a dynamic load is applied is expressed by the following equation (2).
[Expression 2]

It becomes. {U (t)} is a vertical displacement vector of each mass point in FIG. 13, and is expressed by the following equation (3) using vector components u ₁ (t) to u ₈ (t).
[Equation 3]

In formula (2)

Represents.
[0008]
Based on the probabilistic vibration analysis method, the deformation amount evaluation formula of the heat transfer tube is derived by the following formula (4).
[Expression 4]

[0009]
Here, u _i and _rms are root mean square values (hereinafter referred to as effective values) of the displacement of the mass point i of the heat transfer tube model shown in FIG. S _Q , _ev (ω) is the power spectrum of the fluctuating load Q _e (t) acting on the e-th mass point (hereinafter referred to as mass point e), and S _Q , _vv (ω) is the v-th mass point (hereinafter referred to as mass point v). work to say) fluctuating load Q _v power spectrum of (t), W _Q, coherence spectrum of _{ev (ω)} is working with the mass point v Q _e (t) acting on the mass point _{e Q v (t), θ} Q, _ev (ω) is a phase spectrum of Q _e (t) and Q _v (t). n is the number of mass points (= 8), m is the number of eigenmodes, and φ _ij is the component of node i of the j-th eigenmode vector normalized by [M].
[0010]
H _j (omega) is the frequency response function of the j-th order eigenmodes, damping ratio beta _i of j order mode of the tube having the same axial length as the tube model shown in FIG. 13, the natural circular frequency [omega _j The frequency can be calculated according to the following equation (5) using the frequency ω and the imaginary number γ of the fluctuating load.
[Equation 5]

[0011]
H _j (ω) calculated by Expression (5) is input to Expression (4), and the power spectrum S _Q , _ee (ω) and S _Q , _vv (ω) and coherence spectrum W _Q , _ev ( If ω) and the phase spectrum θ _Q , _ev (ω) are input to Equation (4), u _i and _rms can be calculated.
[0012]
From the above, the power spectrum S _Q , _ev (ω), the coherence spectrum W _Q , _ev (ω), and the phase spectrum θ _Q , _ev (ω) of the fluctuating load acting in the tube axis direction of the heat transfer tube shown in FIG. If the physical quantity representing the randomness of the fluctuating load such as) can be measured, it will be understood that the strict evaluation of the heat transfer tube deformation amount can be made by Equation (4).
[0013]
However, the conventional variable load measuring method cannot measure the power spectrum, coherence spectrum, and phase spectrum of the dynamic load in the tube axis direction as described above. Conventional measurement methods are shown in FIGS. These two figures show the research results report of the project of Electric Power Research Institute (project number: 718-2, reporting date: September 1980, report title: A Study of Forces on Immersed Tubes in Fluidized Beds, author: TCKennedy , Oregon State University).
[0014]
14 and 15 will be described in detail. FIG. 14 shows an apparatus for measuring a fluctuating load acting on the entire dummy tube 11 (only the fixed end portion is shown). In this apparatus, a disc 13 is fixed inside a hollow dummy tube 11, and this disc 13 is joined to a support frame 12 with a rivet 18 via a support tube 14 and a support plate 17. Is attached with a strain gauge 15. With such a structure, when the fluid medium collides with the dummy tube 11 and the dummy tube vibrates, this vibration propagates to the support tube 14 and this vibration can be measured by the strain gauge 15. The measured strain can be easily converted into a load, and the variable load acting on the entire region of the dummy tube 11 in the tube axis direction can be measured.
[0015]
FIG. 15 shows a second conventional example and shows an apparatus for measuring a fluctuating load acting on the entire dummy tube 21. In this apparatus, a dummy tube 21 is fixed to a support plate 24 with U bolts 23, and this support plate 24 is joined to a support frame 22 via a support 25. A strain gauge 15 is attached to the support plate 24. It has been. By adopting such a structure, the variable load acting on the entire region of the dummy tube 21 in the tube axis direction is measured as in FIG.
[0016]
[Problems to be solved by the invention]
However, as described above, in the measuring apparatus shown in FIG. 14 or FIG. 15, the fluctuating load acting on the entire region of the dummy tubes 11 and 21 in the tube axis direction can be measured macroscopically. Besides, randomness such as correlation and phase cannot be measured, and as a result, the heat pipe deformation amount cannot be evaluated with high accuracy according to the formula (4).
[0017]
Moreover, such a reason, in the conventional, fluctuating load (Q _i, Q _j and the like) as shown in FIG. 12 for, Q _i, as shown in FIG. 16, such as correlation and phase theta _ij between Q _j Randomness was not taken into account at all, and the method of simply adding the values of fluctuating loads (Q _i , Q _j, etc.) and loading the heat transfer tubes was adopted. This method clearly overestimated the deformation of the heat transfer tube, and the design of the heat transfer tube cross section and tube group support structure had to be extremely unreasonable.
[0018]
An object of the present invention is to eliminate the above-mentioned drawbacks of the prior art and to solve the following technical problems.
(1) Fluidized bed apparatus Provided is a method and apparatus capable of measuring with high accuracy the temporal and spatial distribution and randomness of fluctuating loads necessary for the equation for evaluating the deformation amount of the pipe in the bed.
(2) Using the randomness of the fluctuating load measured according to (1), it is possible to evaluate the deformation amount of the fluidized bed apparatus inner pipe with high accuracy.
[0019]
[Means for Solving the Problems]
The above problem is solved by the following configuration.
In other words, a strain gauge is attached to a selected inner tube or a dummy tube simulating the tube in a fluidized bed apparatus having a tube group in the layer, and the variable load generated in the tube due to the collision of the fluid medium is measured. In this method, the inner tube or the dummy tube is divided into at least two or more in the tube axis direction, and the strain of each divided tube is measured. This is a method for measuring a fluctuating load of a pipe in a fluidized bed apparatus for measuring the properties.
[0020]
As described above, the present invention divides a pipe intended for measurement of a fluctuating load by a fluid medium into a plurality of parts in the tube axis direction, so that even if a fluid medium collides with one of the divided pipes, a load is generated. This load will not propagate to other divided tubes. Thereby, in addition to the distribution of the variable load in the tube axis direction, the randomness such as the correlation and the phase between the variable load tubes can be measured.
[0021]
Here, each of the divided tubes is individually supported by a support tube arranged around the divided tubes so that transmission of force between the divided tubes at least in the tube axis direction is insulated. By supporting, the variable load in the tube axis direction can be measured more accurately.
[0022]
The present invention includes the following configurations.
In other words, a strain gauge is attached to a selected inner tube or a dummy tube simulating the tube in a fluidized bed apparatus having a tube group in the layer, and the variable load generated in the tube due to the collision of the fluid medium is measured. A fluidized bed device for measuring a fluctuating load due to a fluidized medium by dividing an inner tube or a dummy tube into at least two in the tube axis direction and attaching at least one strain gauge to each divided tube This is a variable load measuring device for an in-layer pipe.
[0023]
The fluidized bed apparatus is a support that is arranged around a divided pipe so that the transmission of force between the pipes divided into at least two parts in the pipe axis direction is insulated. You may employ | adopt the structure which supports the divided | segmented pipe | tube separately with a pipe | tube. Further, the fluctuating load measuring device can be configured such that a rhombus hole is formed in the casing of the fluidized bed device and can be inserted and removed.
[0024]
When a variable load measuring device supported at both ends by a rhombus support plate is installed in the rhombus hole in the casing and the variable load measuring device is inserted into the tube group of the fluidized bed device, the variable load measuring device is Is not disturbed, and the fluidized state of the fluidized bed in the fluidized bed apparatus is not hindered.
[0025]
The tubes arranged in the bed of the fluidized bed apparatus to which the measurement method and apparatus of the present invention are applied are for heat transfer tubes, reaction tubes, etc., for heating gas or water, for heat recovery used as piping for various reactions. A pipe or a pipe for controlling the temperature in the bed used for cooling the inside of the fluidized bed. Examples of the heat recovery fluidized bed apparatus include a fluidized bed boiler, a super heater that superheats steam of a steam boiler with a non-corrosive gas, a general process gas heating tube, and a reactive gas reaction tube. The fluidized bed device for controlling the temperature in the bed is a heat transfer tube for adjusting the temperature in the bed such as a waste incinerator.
[0026]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described.
FIG. 1 shows a schematic side view of an embodiment of the present invention. In this embodiment, the strain gauges 15 are attached to the measurement target tubes 201 to 208 divided in the tube axis direction, and the strains 201Z to 208Z when the tubes 201 to 208 are bent in the vertical direction are measured. This makes it possible to evaluate randomness such as correlation and phase in addition to the distribution of fluctuating loads in the tube axis direction.
[0027]
The apparatus shown in FIG. 1 is a flow that is actually used for business purposes, industrial purposes, and the like in an operating state (for example, a cold operating state) in which parts such as the strain gauge 15 and the measurement target tubes 201 to 208 are not burned. It can be used without any problem for both the layer device and the device used for testing. Hereinafter, this example will be described by collectively referring to both of them as “fluidized bed apparatus”.
[0028]
The AA line cross section, BB line cross section and CC line cross section in FIG. 1 are shown in FIG. 2, FIG. 3 and FIG. 4, respectively. Of these three FIGS. 2 to 4, FIG. 3 will be described first, followed by FIGS. 2 and 4 in this order.
[0029]
FIG. 3 shows a cross section of the tube 203 among the measurement target tubes 201 to 208 to which the strain gauge 15 in FIG. 1 is attached. The measurement target tube 203 is supported by tubes 212, 213, and 214 that do not divide both ends of the tube 203 via a T-shaped support plate 210.
[0030]
FIG. 2 shows a cross section of the end portion of the support pipes 212, 213, and 214 shown in FIGS. 1 and 3. It can be seen from FIG. 2 that the ends of the support tubes 212, 213, and 214 are joined to the support plate 215. As shown in FIG. 1, the other ends of the tubes 212, 213, and 214 are supported by a support plate 216. The pipe 211 is also joined to the support plates 215 and 216 for the purpose of not changing the pipe pitch.
[0031]
FIG. 4 shows a cross section at the center point of the distance from the right end of the tube 203 to the left end of the tube 204 among the measurement target tubes 201 to 208 to which the strain gauge 15 in FIG. 1 is attached. is there. As shown in FIG. 4, it can be seen that there are only four support tubes 211 to 214 in the cross section taken along the line CC in FIG. 1, and the measurement target tube 203 and the tube 204 are not continuous.
[0032]
The measurement target tubes 201 to 208 shown in FIG. 1 are manufactured using a low-rigidity material that easily deforms, such as vinyl chloride resin, and the support tubes 211, 212, 213, and 214 and the support plates 210, 215, and 216 are made of iron. What is necessary is just to produce using the highly rigid material which cannot change easily.
[0033]
It is necessary to connect the strain gauge 15 and the strain measuring instrument (not shown) with a lead wire (not shown). Such wiring is formed by connecting the support tubes 211, 212, 213, and 214 together. It can be taken out from a wiring outlet 217 provided in the support plate 215 inside.
[0034]
Since the present embodiment has the structure as described above, the transmission of force between the measurement target tubes 201 to 208 is insulated, and the distribution of variable loads acting on the individual measurement target tubes 201 to 208 in the direction of the tube axis. In addition, correlation and phase can be quantitatively evaluated. Hereinafter, the apparatus shown in FIG. 1 is referred to as a “tube axis direction dynamic load distribution measuring apparatus”.
[0035]
Next, a method for installing the pipe axial direction dynamic load distribution measuring apparatus in the fluidized bed apparatus will be described. FIG. 5 shows the fluidized bed apparatus viewed from the tube axis direction. The tube group 9 is fixed to the casing 106, and the tube group 9 is buried in the fluid medium when the apparatus is operated. A pipe axis direction dynamic load distribution measuring apparatus can be installed at an arbitrary position of such an apparatus. The installation method is as described below.
[0036]
As shown in FIG. 2 (cross-sectional view taken along the line AA in FIG. 1), the support plate 215 of the tube-axis direction dynamic load distribution measuring device has a diamond shape. The reason why the support plate 215 is rhombus is that if the tube axial dynamic load distribution measuring device having the rhombus support plate 215 is inserted into the tube group 9 of the fluidized bed apparatus of FIG. This is because there is no hindrance to the fluid state in the fluidized bed apparatus of FIG.
[0037]
As a specific installation method of the support plate 215, holes 215a to 215i are formed in the casing 106 of the apparatus of FIG. 5 so as to correspond to the diamond-shaped support plate 215 in FIG. A measuring device can be inserted. By adopting such a structure, it is possible to measure the fluid medium fluctuation load at any place (holes 215a to 215i, etc.) in the apparatus.
[0038]
In the present invention, the number of positions of the holes 215a to 215i into which the pipe axial direction dynamic load distribution measuring device is inserted is not particularly limited. In the present invention, in addition to the number and positions of the strain gauges 15 to be attached to the measurement target tubes 201 to 208, the material of the parts such as the support plates 215 and 216 and the support tubes 211, 212, 213, and 214 is also particularly limited. Is not to be done.
[0039]
An example in which the time history waveform, frequency spectrum, and the like of the strains 201Z to 208Z described above are measured using the tube axis direction dynamic load distribution measuring apparatus shown in FIG. In this measurement example, the measuring apparatus shown in FIG. 1 was installed in the hole 215h in the fluidized bed apparatus shown in FIG. As an operating condition of the apparatus, strain measurement was performed in a flow state in which the fluid medium filled in the casing 106 was raised to the upper end of the tube group 9 by the air blown from the air dispersion plate 3. The measurement time of the strain time history waveform was about 15 minutes, the strain frequency band to be measured was 0 to 16 Hz, and the average number of spectra was 32.
[0040]
In the following, for the sake of easy understanding, the tube axis direction dynamic load distribution measuring apparatus shown in FIG. 1 is schematically illustrated as shown in FIG.
FIG. 7 shows time history waveforms of strains 201Z to 204Z among the strains 201Z to 208Z measured by the pipe-axis direction dynamic load distribution measuring apparatus (FIG. 6). Focusing on these time history waveforms, since the waveform heights of the strains 201Z to 204Z are substantially equal, and the concave and convex shapes of the waveforms of the strains 201Z to 204Z substantially match the time axis, the strains 201Z to 204Z Is oscillating with almost the same amplitude and phase.
[0041]
FIG. 8 shows power spectra of the strains 201Z to 204Z shown in FIG. From FIG. 8, the distortion spectrum in the frequency band of 2 to 4 Hz centering on about 3 Hz is dominant in the power spectrum of the distortions 201Z to 204Z. As a result of observing the flow state in the apparatus, the frequency at which the bubbles containing the flow medium collided with the heat transfer tube was about 3 times per second. Therefore, the strain observed in this measurement example is the flow shown in FIG. It can be said that this is due to the collision of the bubble 2 containing the medium 5.
[0042]
FIG. 9 shows a coherence spectrum according to a measurement example in this example. As described above, in the distortion power spectrum shown in FIG. 8, the frequency band component of 2 to 4 Hz is dominant, but according to FIG. 9, the frequency band component of 2 to 4 Hz is also large in the coherence spectrum. As a result of examining the relationship between the tube axis direction distance and the coherence with the tube 201 as a reference point, the tube 202 close to the tube 201 has a high correlation with the tube 201, but as the distance from the tube 201 increases, the tube 203, In the order of 204, the correlation gradually decreases.
[0043]
In FIG. 10, the phase spectrum of distortion 201Z-204Z is shown. Since the power spectrum of distortion has a frequency band component of 2 to 4 Hz centered at about 3 Hz, and the value of the coherence spectrum is large in this band, in this embodiment, the phase value at the point where the frequency of the phase spectrum is 3 Hz. Focused on. According to this, the strains 202Z, 203Z and 204Z of the tubes 201 to 204 with respect to the strain 201Z are substantially in phase regardless of the distance from the tube 201 which is the reference point, and strains in the same direction are generated in the tubes 201 to 204. I found out.
[0044]
【The invention's effect】
According to the present invention, the following matters are realized.
(1) In the fluidized bed apparatus, it is possible to measure the temporal and spatial distribution and randomness of the fluctuating load generated in the tube group by the collision of the fluid medium.
(2) Considering the randomness measured in the above (1), it is possible to evaluate the deformation amount of the heat transfer tube with high accuracy and rationality.
[0045]
(3) Based on the highly accurate and rational deformation amount evaluation of the heat transfer tubes described in (2) above, it is possible to evaluate the reliability of the in-layer heat transfer tube group and the tube group support structure of the fluidized bed apparatus.
(4) By controlling the operation state of the fluidized bed apparatus based on the result of the reliability evaluation according to (3), the fluidized bed apparatus can be stably operated without damaging the apparatus itself.
[Brief description of the drawings]
FIG. 1 is a diagram showing an embodiment of a fluctuating load measuring apparatus according to the present invention.
2 is a cross-sectional view taken along line AA of the fluctuating load measuring apparatus of FIG.
3 is a cross-sectional view of the fluctuating load measuring device of FIG. 1 taken along the line BB.
4 is a cross-sectional view taken along line CC of the fluctuating load measuring apparatus of FIG.
5 is a fluidized bed sectional view in which the fluctuating load measuring device of FIG. 1 is arranged in a fluidized bed. FIG.
6 is a schematic diagram of the fluctuating load measuring apparatus shown in FIG.
FIG. 7 shows a distortion time history waveform and a power spectrum as an example of an effect peculiar to the present invention.
FIG. 8 shows a time history waveform of a distortion and a power spectrum as an example of an effect unique to the present invention.
FIG. 9 shows a coherence spectrum and a phase spectrum of distortion as an example of an effect unique to the present invention.
FIG. 10 shows a coherence spectrum and a phase spectrum of distortion as an example of an effect unique to the present invention.
FIG. 11 is a schematic view of a fluidized bed boiler to which the fluctuating load measuring device of the present invention is applied.
FIG. 12 is a diagram showing the relationship between the fluctuating load acting in the tube axis direction of the heat transfer tube and the deformation amount of the heat transfer tube.
FIG. 13 shows a concentrated mass point model of a pipe.
FIG. 14 shows a conventional variable load measuring apparatus.
FIG. 15 shows a conventional variable load measuring apparatus.
FIG. 16 shows an outline of a method for evaluating a deformation amount of a heat transfer tube.
[Explanation of symbols]
3 Air dispersion plate 9 Tube group 15 Strain gauge 106 Casing 201-208 Measuring object tube 201Z-208Z Strain 212-214 Non-divided support tube 210, 215, 216 Support plate 211 Support tube 217 Wiring outlet

Claims (5)

A method of measuring a fluctuating load generated in a pipe by collision of a fluid medium by attaching a strain gauge to a selected inner pipe or a dummy pipe simulating the pipe in a fluid bed apparatus having a pipe group in the bed In
Measure the temporal or spatial distribution and randomness of the fluctuating load due to the fluidized medium by dividing the inner tube or dummy tube into at least two in the tube axis direction and measuring the strain of each divided tube. A method for measuring a fluctuating load of a pipe in a fluidized bed apparatus. 2. The fluidized bed apparatus layer according to claim 1, wherein each of the divided pipes is individually supported so that transmission of force between each of the pipes divided into at least two in the pipe axis direction is insulated. Fluctuating load measurement method for inner pipe. A device that measures a fluctuating load generated in a pipe by collision of a fluid medium by attaching a strain gauge to a selected inner pipe or a dummy pipe simulating the pipe in a fluid bed apparatus having a tube group in the bed In
A fluidized bed characterized in that an inner layer pipe or a dummy pipe is divided into at least two in the axial direction of the pipe, and at least one strain gauge is attached to each of the divided pipes to measure a fluctuating load due to a fluid medium. Fluctuating load measuring device for pipes in the device layer. The divided pipes are individually supported by support pipes arranged around the divided pipes so that the transmission of force between the pipes divided into at least two parts in the tube axis direction is insulated. The fluidized bed apparatus according to claim 3, wherein the fluctuating load measuring device for the inner pipe of the bed. 5. A fluidized bed apparatus in which a fluctuating load measuring device of a fluidized bed apparatus inner pipe supported at both ends by a rhombus support plate is detachably attached to a rhombus hole provided in a casing of the fluidized bed apparatus. Fluidized bed device Fluctuating load measuring device for inner tube of bed.

Images