JP4476540B2

JP4476540B2 - Pipe blockage detection device

Info

Publication number: JP4476540B2
Application number: JP2002297174A
Authority: JP
Inventors: 宣夫宮地
Original assignee: Yokogawa Electric Corp
Current assignee: Yokogawa Electric Corp
Priority date: 2002-10-10
Filing date: 2002-10-10
Publication date: 2010-06-09
Anticipated expiration: 2022-10-10
Also published as: JP2004132817A

Description

【発明の属する技術分野】
本発明は、導圧管の詰まりを検出できる管路閉塞検出装置に関し、特にどのようなモードでもどの導圧管が詰まっているかを判定することができる管路閉塞検出装置に関するものである。
【０００１】
【従来の技術】
特許文献１には、差圧伝送器の導圧管路の閉塞を検出する装置の発明が記載されている。以下、この発明の概要を説明する。
【０００２】
図３はこの管路閉塞検出装置の一実施例の構成図である。図３において、測定対象７１が流れる管路７３内にオリフィス７２が設置されている。このオリフィス７２の高圧側と低圧側の圧力はそれぞれ導圧管７４ａ、７４ｂで差圧検出器７５に導かれて、高圧側の静圧及び差圧が検出される。これらの静圧および差圧は差分回路７６に入力されて低圧側の静圧が演算される。
【０００３】
高圧側および低圧側の静圧と差圧データは圧力データの記憶回路７７に蓄えられる。圧力揺動の度合計算回路７８は圧力データの記憶回路７７に蓄えられた圧力データから各圧力の揺動の度合いを計算する。相関計算回路７９は圧力揺動の度合計算回路７８が計算した各圧力の揺動の度合いの相関係数を計算する。
【０００４】
相関関係記録回路８１には導圧詰まり時の相関関係を示す値が格納されている。詰まり診断回路８２は相関計算回路７９が計算した相関値と相関関係記録回路８１に格納されているデータを比較して導圧管７４ａ、７４ｂの詰まり具合を計算して、詰まり診断結果信号８３を出力する。
【０００５】
導圧管７４ａ、７４ｂが詰まると、静圧および差圧の揺動幅が変化し、これによって導圧管の詰まりを判断することができる。例えば、導圧管７４ａ、７４ｂの両方が詰まると、差圧と静圧の両方の揺動幅が小さくなる。また、高圧側の導圧管７４ａのみが詰まると、差圧の揺動幅が大きくなり、静圧の揺動幅が小さくなる。さらに、低圧側の導圧管７４ｂのみ詰まると、差圧の揺動幅が大きくなり、静圧の揺動幅は変化しない。これらの揺動幅の変化は静圧と差圧の相関関係から求めることができる。
【０００６】
【特許文献１】
特許第３１２９１２１号明細書
【０００７】
【発明が解決しようとする課題】
しかしながら、このような管路閉塞検出装置には次のような課題があった。
【０００８】
前述したように、静圧と差圧の相関関係を計算することにより、理論上は高圧側導圧管７４ａ、低圧側導圧管７４ｂの詰まりを判断することができる。しかしながら、実際には相関係数を基準値と比較するだけでは、高圧側導圧管７４ａと低圧側導圧管７４ｂのうちどの導圧管が詰まっているかを明確に確定することができないという課題があった。また、どちら一方の導圧管が詰まっているか、あるいは両方の導圧管が詰まっているかを確実に検出することができないという課題もあった。
【０００９】
従って本発明が解決しようとする課題は、どの導圧管が詰まっているかを明確に特定することができる管路閉塞検出装置を提供することにある。
【００１０】
【課題を解決するための手段】
このような課題を解決するために、本発明のうち請求項１記載の発明は、２本の導圧管の間の差圧信号および前記導圧管のうちどちらか一方の前記導圧管の静圧信号が入力され、これら差圧信号と静圧信号の隣接するデータ間の差に基づくそれぞれの揺動を演算するとともにこれら差圧揺動の２乗和と静圧揺動の２乗和を演算し分散として出力する分散演算部と、この分散演算部の出力が入力され、前記差圧信号の分散と前記静圧信号の分散の比を演算して出力する比率演算部と、この比率演算部の出力が入力され、この入力値から前記導圧管の詰まりを判定する判定部とを有し、この判定部でどの導圧管が詰まっているかを判定するようにしたものである。確実に詰まりを検出することができる。
【００１１】
請求項２記載の発明は、請求項１記載の発明において、前記判定部は、入力された前記比率が１または１に近い値のときに前記導圧管のうち前記静圧信号を取った側と反対側の導圧管が詰まっていると判定し、前記入力された比率が１よりかなり大きいときに前記導圧管のうち前記静圧信号を取った側の導圧管が詰まっていると判定するようにしたものである。確実に詰まりを検出できる。
【００１３】
請求項３記載の発明は、２本の導圧管の間の差圧信号およびどちらか一方の前記導圧管の静圧信号が入力され、これらの隣接するデータ間の差に基づくそれぞれの信号の揺動を演算して出力する揺動演算部と、この揺動演算部の出力が入力され、これら２つの信号の相互相関係数および前記静圧信号の自己相関係数を演算する相関演算部と、この相関演算部の出力が入力され、前記相互相関係数および前記自己相関係数の比を演算して出力する比率演算部と、この比率演算部の出力が入力され、この入力値から前記導圧管の詰まりを判定する判定部とを有し、この判定部により前記導圧管の詰まりを判定するようにしたものである。確実に導圧管の詰まりを検出できる。
【００１４】
請求項４記載の発明は、請求項３記載の発明において、前記判定部は、入力された前記比率が１または１に近い値のときに前記導圧管のうち前記静圧信号を取った側と反対側の導圧管が詰まっていると判定し、前記入力された比率が０または０に近いときに前記導圧管のうち前記静圧信号を取った側の導圧管が詰まっていると判定するようにしたものである。確実に導圧管の詰まりを検出できる。
【００１５】
請求項５記載の発明は、２本の導圧管の間の差圧信号およびどちらか一方の前記導圧管の静圧信号が入力され、これらの信号の隣接するデータ間の差に基づくそれぞれの揺動を演算するとともにこれら差圧揺動の２乗和と静圧揺動の２乗和を演算し分散として出力する分散演算部と、この分散演算部の出力が入力され、前記差圧信号の分散と前記静圧信号の分散の比率を演算する比率演算部と、この比率演算部の出力および前記分散演算部が出力する前記差圧信号の分散が入力される判定部とを有し、この判定部は前記差圧信号の分散を所定の基準値と比較して前記２本の導圧管の両方が詰まっているかどうかを判定し、前記比率演算部が出力する比率の値から前記２本の導圧管のうちどちらかが詰まっているかどうかを判定するようにしたものである。全てのモードの詰まりに対応できる。
【００１６】
請求項６記載の発明は、請求項５記載の発明において、前記判定部は、入力された前記比率が１または１に近い値のときに前記導圧管のうち前記静圧信号を取った側と反対側の導圧管が詰まっていると判定し、前記入力された比率が１よりかなり大きいときに前記導圧管のうち前記静圧信号を取った側の導圧管が詰まっていると判定するようにしたものである。確実に導圧管の詰まりを検出できる。
【００１８】
請求項７記載の発明は、２本の導圧管の間の差圧信号およびどちらか一方の前記導圧管の静圧信号が入力され、これら差圧信号と静圧信号の隣接するデータ間の差に基づくそれぞれの揺動を演算するとともにこれら差圧揺動の２乗和と静圧揺動の２乗和を演算し分散として出力する分散演算部と、前記差圧信号および前記静圧信号が入力され、これら隣接するデータ間の信号の揺動を演算して出力する揺動演算部と、この揺動演算部の出力が入力され、前記差圧信号の揺動と前記静圧信号の揺動との相互相関係数および前記静圧信号の揺動の自己相関係数を演算する相関演算部と、この相関演算部の出力が入力され、前記相互相関係数と前記自己相関係数の比率を演算する比率演算部と、この比率演算部の出力および前記分散演算部が出力する前記差圧信号の分散が入力される判定部とを有し、この判定部は前記差圧信号の分散を所定の基準値と比較して前記２本の導圧管の両方が詰まっているかどうかを判定し、前記比率演算部が出力する比率の値から前記２本の導圧管のうちどちらかが詰まっているかどうかを判定するようにしたものである。全てのモードの詰まりに対応することができる。
【００１９】
請求項８記載の発明は、請求項７記載の発明において、前記判定部は、入力された前記比率が１または１に近い値のときに前記導圧管のうち前記静圧信号を取った側と反対側の導圧管が詰まっていると判定し、前記入力された比率が０または０に近いときに前記導圧管のうち前記静圧信号を取った側の導圧管が詰まっていると判定するようにしたものである。確実に導圧管の詰まりを検出できる。
【００２１】
５は管路閉塞検出装置であり、差圧伝送器４が検出した高圧側の静圧および差圧信号が入力される。管路閉塞検出装置５は、分散演算部５２、比率演算部５３および判定部５４から構成される。また、分散演算部５２は揺動演算部５２１および２乗和演算部５２２から構成される。
【００２２】
差圧伝送器４内で演算された静圧データおよび差圧データの所定時間の平均値は分散演算部５２内の揺動演算部５２１に入力される。揺動演算部５２１は下記（１）、（２）式に基づいて隣り合う静圧および差圧データの差の揺動を演算して出力する。
ｉ番目の差圧揺動値Ｆ_Δ _P,i＝ΔＰ_i−ΔＰ_i-1・・・(1)
ｉ番目の静圧揺動値Ｆ_PH,i＝ＰＨ_i−ＰＨ_i-1・・・(2)
但し、
ΔＰ_i，ΔＰ_i-1：ｉ、（ｉ−１）番目の差圧データ
ＰＨ_i，ＰＨ_i-1：ｉ、（ｉ−１）番目の差圧データ
【００２３】
この差圧揺動値Ｆ_Δ _P、静圧揺動値Ｆ_PHは（時間の要素ｉは省く）２乗和演算部５２２に入力される。２乗和演算部５２２は下記（３）、（４）式に基づいて、ｎ個の揺動値の各々を２乗して、これらの２乗した値を加算する。この加算値をそれぞれ差圧信号、静圧信号の分散という。
【００２４】
【数２】

なお、上記（３）、（４）式のΣの下の“ｎ”は、ｎ個加算することを表しており、通常時系列的に引き続いた差圧あるいは静圧の揺動値Ｆ_ΔＰ、Ｆ_ＰＨの２乗を加算する。
【００２５】
２乗和演算部５２２の出力は比率演算部５３に入力され、下記（５）式に基づいて差圧信号の分散と静圧信号の分散の比率Ｒ_Ｖが演算される。
Ｒ_Ｖ＝Ｖ_ΔＰ／Ｖ_ＰＨ・・・・・・・・・・・・・・・・・・・・（５）
この比率Ｒ_Ｖおよび２乗和演算部５２２が出力する差圧揺動の２乗和Ｖ_ΔＰは判定部５４に入力され、これらの入力からどの導圧管が詰まっているかが判定される。
【００２６】
次に、判定部５４の動作を説明する。導圧管３１，３２が詰まると、周波数が高い揺動は差圧伝送器４に伝わり難くなる。すなわち、導圧管３１，３２の詰まりは時定数Ｔの１次遅れ系で表すことができる。詰まりが大きくなると時定数Ｔも大きくなる。また差圧伝送器４のカプセル（感圧部）および圧力信号を増幅するアンプも時定数Ｔ_{ｔｒａｎｓ}の１次遅れ系で表すことができる。このことから、導圧管３１，３２のいずれかが詰まると、詰まった側の静圧の揺動が小さくなることがわかる。
【００２７】
判定部５４は２乗和演算部５２２が出力した差圧揺動の２乗和を正常時（導圧管３１，３２のいずれも詰まっていない状態）の値と比較して、導圧管３１，３２の両方が詰まっているかどうかを判定する。両方の導圧管が詰まっていると差圧の周波数が高い揺動は小さくなるので、差圧の揺動の２乗和、すなわち分散が小さくなる。このことから、両方の導圧管が詰まっているかどうかを判定することができる。
【００２８】
前述したように、高圧側の導圧管３１が詰まると前記（２）式の静圧の揺動Ｆ_ＰＨがゼロに近くなるので、前記（４）式の静圧揺動の分散が小さくなり、分散の比率Ｒ_Ｖは大きくなる。また、低圧側の導圧管３２が詰まると低圧側の静圧揺動はゼロに近くなるので、高圧側の静圧揺動Ｆ_ＰＨと差圧揺動Ｆ_ΔＰはほぼ等しくなる。そのため、前記（５）式の分散の比率Ｒ_Ｖは１に近づく。このようにして、分散の比率Ｒ_Ｖからどちら側の導圧管が詰ったかを検出することができる。
【００２９】
すなわち、差圧の分散Ｖ_ΔＰを正常値の値と比較し、かつ差圧の分散Ｖ_ΔＰと静圧の分散Ｖ_ＰＨの分散比Ｒ_Ｖの値から、どちらかの導圧管が詰まっているか、あるいは両方の導圧管が詰まっているかを確定することができる。高圧側の導圧管３１が詰まっても差圧の分散Ｖ_ΔＰが正常値を示すことがあるので、分散の比率Ｒ_Ｖを用いて片方の導圧管が詰まっているかどうかを判定するようにする。
【００３０】
なお、この実施例では高圧側の静圧を用いたが、低圧側の静圧を用いるようにしてもよい。低圧側の静圧を用いた場合、高圧側の導圧管が詰まると差圧の分散Ｖ_ΔＰと静圧の分散Ｖ_ＰＨがほぼ等しくなるので、これらの比率はほぼ１に等しくなる。また、低圧側の導圧管が詰まると静圧の分散が小さくなり、分散の比率は大きくなる。このようにして、どちらの導圧管が詰まっているかを判定することができる。
【００３１】
図２に本発明の他の実施例を示す。なお、図１と同じ要素には同一符号を付し、説明を省略する。図２において、６は管路閉塞検出装置であり、分散演算部６２，揺動演算部６３，相関演算部６４，比率演算部６５および判定部６６で構成される。また、分散演算部６２は揺動演算部６２１および２乗和演算部６２２で構成される。
【００３２】
差圧伝送器４内で演算された差圧信号は分散演算部６２に入力される。分散演算部６２は分散演算部５２と同様に、前記（１）式によって差圧の揺動値Ｆ_ΔＰを演算し、前記（３）式によって差圧揺動の２乗和、すなわち分散を演算して判定部６６に出力する。
【００３３】
差圧信号と静圧信号は揺動演算部６３にも入力される。揺動演算部６３は前記（１）、（２）式に基づいて差圧の揺動値Ｆ_ΔＰおよび静圧の揺動値Ｆ_ＰＨを演算して相関演算部６４に出力する。相関演算部６４は下記（６）式に基づいて差圧揺動値Ｆ_ΔＰと静圧揺動値Ｆ_ＰＨの相互相関係数Ｃ_１を演算し、下記（７）式に基づいて静圧揺動値Ｆ_ＰＨの自己相関係数Ｃ_２を演算する。
【００３４】
【数３】

なお、Σの下の“ｎ”はｎ個の揺動値について相関係数を演算することを表している。
【００３５】
相関演算部６４で演算された２つの相関は比率演算部６５に入力される。比率演算部６５は下記（８）式により、２つの相関の比率Ｒ_Ｃを演算して判定部６６に出力する。
【数４】

【００３６】
次に、判定部６６の動作を説明する。判定部６６は差圧の分散Ｖ_ΔＰを正常値のそれと比較して、導圧管３１，３２の両方が詰まっているかどうかを判定する。この判定手順は図１実施例と同じなので、詳細を省略する。
【００３７】
次に、判定部６６は比率演算部６５の出力である相関の比率Ｒ_Ｃにより導圧管３１，３２のどちらかが詰まっているかどうかを判定する。低圧側の導圧管３２のみが詰まると、低圧側の静圧揺動はゼロに近くなり、差圧の揺動は高圧側の静圧揺動に近い値になる。そのため、前記（６）式の差圧揺動と静圧揺動の相互相関係数Ｃ_１の値は前記（７）式の静圧揺動の自己相関Ｃ_２に近い値になり、これらの比率Ｒ_Ｃは１に近い値をとる。
【００３８】
これに対して、高圧側の導圧管３１のみが詰まると、差圧揺動は低圧側の静圧揺動に近い値をとる。そのため、高圧側の静圧揺動と差圧揺動の間の関連性がなくなり、高圧側の静圧揺動と差圧揺動の相互相関係数Ｃ_１はゼロに近い値、場合によっては負の値になる。このように、相関係数の比率を計算することによって、高圧側または低圧側の導圧管の詰まりを検出することができる。
【００３９】
なお、この実施例も図１の実施例と同じように、静圧として低圧側の圧力を用いることも出来る。この場合、高圧側の導圧管３１が詰まると差圧揺動と静圧揺動は同程度の値になり、比率Ｒ_Ｃは１に近い値を取る。これに対して、低圧側の導圧管３２が詰まると差圧揺動と静圧揺動との間に関連性がなくなるため相互相関係数Ｃ_１がゼロ近くの値になり、比率Ｒ_Ｃも同様の値を取る。
【００４０】
また、前記（１）、（２）式の差圧揺動Ｆ_ΔＰ、ｉ、静圧揺動Ｆ_ＰＨ，ｉの計算は直近の２つの差圧データまたは静圧データを用いることがのぞましい。
【００４１】
さらに、高圧側導圧管３１、低圧側導圧管３２のうちどちらかの導圧管の詰まりを検出するだけなら、前記（３）式の差圧の分散ＶΔＰを正常時の基準値と比較する必要はなく、前記（５）式の分散の比率ＲＶまたは前記（８）式の相関係数の比率ＲＣの値を調べるだけでよい。
【発明の効果】
以上説明したことから明らかなように、本発明によれば、次の効果が期待できる。
請求項１記載の発明によれば、２本の導圧管の間の差圧信号および前記導圧管のうちどちらか一方の前記導圧管の静圧信号が入力され、これら差圧信号と静圧信号の隣接するデータ間の差に基づくそれぞれの揺動を演算するとともにこれら差圧揺動の２乗和と静圧揺動の２乗和を演算し分散として出力する分散演算部と、この分散演算部の出力が入力され、前記差圧信号の分散と前記静圧信号の分散の比を演算して出力する比率演算部と、この比率演算部の出力が入力され、この入力値から前記導圧管の詰まりを判定する判定部とを有し、この判定部でどの導圧管が詰まっているかを判定するようにした。
【００４２】
導圧管の詰まりによる統計量である分散の比率変化のみを検出する事によってどの導圧管が詰まっているかを判定する方式であるので、実際のプロセスの流量範囲や揺動の大小など、プラントの運転条件に左右されずに正確な検出を行うことができるという効果がある。
【００４３】
請求項２記載の発明によれば、請求項１記載の発明において、前記判定部は、入力された前記比率が１または１に近い値のときに前記導圧管のうち前記静圧信号を取った側と反対側の導圧管が詰まっていると判定し、前記入力された比率が１よりかなり大きいときに前記導圧管のうち前記静圧信号を取った側の導圧管が詰まっていると判定するようにした。比率の大小を比較するだけなので、簡単かつ確実に導圧管の詰まりを検出することができるという効果がある。
【００４５】
請求項３記載の発明によれば、２本の導圧管の間の差圧信号およびどちらか一方の前記導圧管の静圧信号が入力され、これらの隣接するデータ間の差に基づくそれぞれの信号の揺動を演算して出力する揺動演算部と、この揺動演算部の出力が入力され、これら２つの信号の相互相関係数および前記静圧信号の自己相関係数を演算する相関演算部と、この相関演算部の出力が入力され、前記相互相関係数および前記自己相関係数の比を演算して出力する比率演算部と、この比率演算部の出力が入力され、この入力値から前記導圧管の詰まりを判定する判定部とを有し、この判定部により前記導圧管の詰まりを判定するようにした。
【００４６】
導圧管の詰まりによる統計量である相関係数の比率変化のみを検出する事によってどの導圧管が詰まっているかを判定する方式であるので、実際のプロセスの流量範囲や揺動の大小など、プラントの運転条件に左右されずに正確な検出を行うことができるという効果がある。
【００４７】
請求項４記載の発明によれば、請求項３記載の発明において、前記判定部は、入力された前記比率が１または１に近い値のときに前記導圧管のうち前記静圧信号を取った側と反対側の導圧管が詰まっていると判定し、前記入力された比率が０または０に近いときに前記導圧管のうち前記静圧信号を取った側の導圧管が詰まっていると判定するようにした。比率の大小を比較するだけなので、簡単かつ確実に導圧管の詰まりを検出することができるという効果がある。
【００４８】
請求項５記載の発明によれば、２本の導圧管の間の差圧信号およびどちらか一方の前記導圧管の静圧信号が入力され、これらの信号の隣接するデータ間の差に基づくそれぞれの揺動を演算するとともにこれら差圧揺動の２乗和と静圧揺動の２乗和を演算し分散として出力する分散演算部と、この分散演算部の出力が入力され、前記差圧信号の分散と前記静圧信号の分散の比率を演算する比率演算部と、この比率演算部の出力および前記分散演算部が出力する前記差圧信号の分散が入力される判定部とを有し、この判定部は前記差圧信号の分散を所定の基準値と比較して前記２本の導圧管の両方が詰まっているかどうかを判定し、前記比率演算部が出力する比率の値から前記２本の導圧管のうちどちらかが詰まっているかどうかを判定するようにした。
【００４９】
導圧管の詰まりによる統計量である分散とその比率変化のみを検出する事によってどの導圧管が詰まっているかを判定する方式であるので、実際のプロセスの流量範囲や揺動の大小など、プラントの運転条件に左右されずに正確な検出を行うことができるという効果がある。また、片側の導圧管のみが詰まっている場合、両方の導圧管が詰まっている場合の全てのモードの詰まりに対して正確に詰まりを検出することができるという効果もある。
【００５０】
請求項６記載の発明によれば、請求項５記載の発明において、前記判定部は、入力された前記比率が１または１に近い値のときに前記導圧管のうち前記静圧信号を取った側と反対側の導圧管が詰まっていると判定し、前記入力された比率が１よりかなり大きいときに前記導圧管のうち前記静圧信号を取った側の導圧管が詰まっていると判定するようにした。分散とその比率を所定の値と比較するだけなので、簡単かつ確実に導圧管の詰まりを検出することができるという効果がある。
【００５２】
請求項７の発明によれば、２本の導圧管の間の差圧信号およびどちらか一方の前記導圧管の静圧信号が入力され、これら差圧信号と静圧信号の隣接するデータ間の差に基づくそれぞれの揺動を演算するとともにこれら差圧揺動の２乗和と静圧揺動の２乗和を演算し分散として出力する分散演算部と、前記差圧信号および前記静圧信号が入力され、これら隣接するデータ間の信号の揺動を演算して出力する揺動演算部と、この揺動演算部の出力が入力され、前記差圧信号の揺動と前記静圧信号の揺動との相互相関係数および前記静圧信号の揺動の自己相関係数を演算する相関演算部と、この相関演算部の出力が入力され、前記相互相関係数と前記自己相関係数の比率を演算する比率演算部と、この比率演算部の出力および前記分散演算部が出力する前記差圧信号の分散が入力される判定部とを有し、この判定部は前記差圧信号の分散を所定の基準値と比較して前記２本の導圧管の両方が詰まっているかどうかを判定し、前記比率演算部が出力する比率の値から前記２本の導圧管のうちどちらかが詰まっているかどうかを判定するようにした。
【００５３】
導圧管の詰まりによる統計量である分散および相関係数の比率変化のみを検出する事によってどの導圧管が詰まっているかを判定する方式であるので、実際のプロセスの流量範囲や揺動の大小など、プラントの運転条件に左右されずに正確な検出を行うことができるという効果がある。また、片側の導圧管のみが詰まっている場合、両方の導圧管が詰まっている場合の全てのモードの詰まりに対して正確に詰まりを検出することができるという効果もある。
【００５４】
請求項８記載の発明によれば、請求項７記載の発明において、前記判定部は、入力された前記比率が１または１に近い値のときに前記導圧管のうち前記静圧信号を取った側と反対側の導圧管が詰まっていると判定し、前記入力された比率が０または０に近いときに前記導圧管のうち前記静圧信号を取った側の導圧管が詰まっていると判定するようにした。分散と相関係数の比率を所定の値と比較するだけなので、簡単かつ確実に導圧管の詰まりを検出することができるという効果がある。
【図面の簡単な説明】
【図１】本発明の一実施例を示す構成図である。
【図２】本発明の他の実施例を示す構成図である。
【図３】従来の管路閉塞検出装置の構成図である。
【符号の説明】
３１，３２導圧管
４差圧伝送器
５、６管路閉塞検出装置
５２，６２分散演算部
５２１，６２１，６３揺動演算部
５２２、６２２２乗和演算部
５３、６５比率演算部
５４，６６判定部
６４相関演算部BACKGROUND OF THE INVENTION
The present invention relates to a conduit blockage detecting device capable of detecting clogging of a pressure guiding tube, and more particularly to a conduit blockage detecting device capable of determining which pressure guiding tube is clogged in any mode.
[0001]
[Prior art]
Patent Document 1 describes an invention of an apparatus for detecting blockage of a pressure guiding line of a differential pressure transmitter. The outline of the present invention will be described below.
[0002]
FIG. 3 is a block diagram of an embodiment of this pipe blockage detecting device. In FIG. 3, an orifice 72 is installed in a pipe 73 through which a measurement object 71 flows. The high pressure side pressure and the low pressure side pressure of the orifice 72 are respectively guided to the differential pressure detector 75 by pressure guiding pipes 74a and 74b, and the high pressure side static pressure and differential pressure are detected. These static pressure and differential pressure are input to the difference circuit 76, and the low-pressure side static pressure is calculated.
[0003]
The high pressure side and low pressure side static pressure and differential pressure data are stored in the pressure data storage circuit 77. The pressure fluctuation degree calculation circuit 78 calculates the degree of fluctuation of each pressure from the pressure data stored in the pressure data storage circuit 77. The correlation calculation circuit 79 calculates a correlation coefficient of the degree of pressure fluctuation calculated by the pressure fluctuation degree calculation circuit 78.
[0004]
The correlation recording circuit 81 stores a value indicating the correlation at the time of pressure clogging. The clogging diagnosis circuit 82 compares the correlation value calculated by the correlation calculation circuit 79 with the data stored in the correlation recording circuit 81 to calculate the clogging degree of the pressure guiding tubes 74a and 74b, and outputs a clogging diagnosis result signal 83. To do.
[0005]
When the pressure guiding pipes 74a and 74b are clogged, the fluctuation widths of the static pressure and the differential pressure are changed, whereby the clogging of the pressure guiding pipes can be determined. For example, when both of the pressure guiding tubes 74a and 74b are clogged, the swing widths of both the differential pressure and the static pressure are reduced. Further, when only the high pressure side pressure guide tube 74a is clogged, the rocking width of the differential pressure becomes large and the rocking width of the static pressure becomes small. Furthermore, if only the pressure guide tube 74b on the low pressure side is clogged, the fluctuation width of the differential pressure increases and the fluctuation width of the static pressure does not change. These changes in the swing width can be obtained from the correlation between the static pressure and the differential pressure.
[0006]
[Patent Document 1]
Japanese Patent No. 3129121 [0007]
[Problems to be solved by the invention]
However, such a pipe blockage detecting device has the following problems.
[0008]
As described above, by calculating the correlation between the static pressure and the differential pressure, it is theoretically possible to determine whether the high pressure side pressure guiding tube 74a or the low pressure side pressure guiding tube 74b is clogged. However, in practice, there is a problem that it is not possible to clearly determine which of the high pressure side pressure guiding tube 74a and the low pressure side pressure guiding tube 74b is clogged only by comparing the correlation coefficient with the reference value. . In addition, there is a problem that it is impossible to reliably detect which one of the pressure guiding tubes is clogged or whether both of the pressure guiding tubes are clogged.
[0009]
Therefore, the problem to be solved by the present invention is to provide a conduit blockage detecting device that can clearly identify which pressure guiding tube is clogged.
[0010]
[Means for Solving the Problems]
In order to solve such a problem, the invention according to claim 1 of the present invention is a differential pressure signal between two pressure guiding tubes and a static pressure signal of one of the pressure guiding tubes. Is calculated, and the respective fluctuations based on the difference between adjacent data of the differential pressure signal and the static pressure signal are calculated, and the square sum of the differential pressure fluctuations and the square sum of the static pressure fluctuations are calculated. A dispersion calculation unit that outputs the variance, an output of the dispersion calculation unit, a ratio calculation unit that calculates and outputs a ratio of the variance of the differential pressure signal and the variance of the static pressure signal, and a ratio calculation unit An output is input, and a determination unit that determines clogging of the pressure guiding tube from the input value is provided, and the determination unit determines which pressure guiding tube is clogged. Clogging can be detected reliably.
[0011]
According to a second aspect of the present invention, in the first aspect of the invention, the determination unit includes a side of the pressure guiding tube that has received the static pressure signal when the input ratio is 1 or a value close to 1. It is determined that the pressure guiding tube on the opposite side is clogged, and it is determined that the pressure guiding tube on the side that has received the static pressure signal is clogged when the input ratio is considerably larger than 1. It is a thing. Clogging can be detected reliably.
[0013]
According to the third aspect of the present invention, a differential pressure signal between two pressure guiding pipes and a static pressure signal of one of the pressure guiding pipes are inputted, and the fluctuation of each signal based on the difference between these adjacent data is input. A swing calculation unit that calculates and outputs a motion, and a correlation calculation unit that receives the output of the swing calculation unit and calculates a cross-correlation coefficient of these two signals and an autocorrelation coefficient of the static pressure signal; The output of the correlation calculation unit is input, the ratio calculation unit that calculates and outputs the ratio of the cross-correlation coefficient and the autocorrelation coefficient, and the output of the ratio calculation unit is input. A determination unit that determines clogging of the pressure guiding tube, and the determination unit determines clogging of the pressure guiding tube. The clogging of the pressure guiding tube can be detected reliably.
[0014]
According to a fourth aspect of the present invention, in the third aspect of the present invention, the determination unit includes a side of the pressure guiding tube that has received the static pressure signal when the input ratio is 1 or a value close to 1. It is determined that the pressure guiding tube on the opposite side is clogged, and when the input ratio is 0 or close to 0, it is determined that the pressure guiding tube on the side that has received the static pressure signal is clogged. It is a thing. The clogging of the pressure guiding tube can be detected reliably.
[0015]
According to the fifth aspect of the present invention, a differential pressure signal between two pressure guiding pipes and a static pressure signal of one of the pressure guiding pipes are input, and each fluctuation based on a difference between adjacent data of these signals is input. A dispersion calculating unit that calculates the motion and calculates the square sum of the differential pressure fluctuation and the square sum of the static pressure fluctuation and outputs the variance, and an output of the dispersion calculating unit is input, and the differential pressure signal A ratio calculator that calculates a ratio of variance and variance of the static pressure signal; and a determination unit that receives the output of the ratio calculator and the variance of the differential pressure signal output by the variance calculator. The determination unit compares the variance of the differential pressure signal with a predetermined reference value to determine whether both of the two pressure guiding tubes are clogged, and determines the two values from the ratio value output by the ratio calculation unit. Judgment is made as to whether one of the impulse lines is clogged. Than is. It can cope with clogging of all modes.
[0016]
According to a sixth aspect of the present invention, in the fifth aspect of the present invention, the determination unit includes a side of the pressure guiding tube that has received the static pressure signal when the input ratio is 1 or a value close to 1. It is determined that the pressure guiding tube on the opposite side is clogged, and it is determined that the pressure guiding tube on the side that has received the static pressure signal is clogged when the input ratio is considerably larger than 1. It is a thing. The clogging of the pressure guiding tube can be detected reliably.
[0018]
According to the seventh aspect of the present invention, a differential pressure signal between two pressure guiding tubes and a static pressure signal of one of the pressure guiding tubes are input, and a difference between adjacent data of these differential pressure signals and the static pressure signal is input. A dispersion calculating unit for calculating each of the oscillations based on the differential pressure oscillation and calculating the square sum of the differential pressure oscillations and the square sum of the static pressure oscillations, and outputting them as variances, and the differential pressure signal and the static pressure signal The fluctuation calculation unit that calculates and outputs the fluctuation of the signal between the adjacent data that is input and the output of the fluctuation calculation unit are input, and the fluctuation of the differential pressure signal and the fluctuation of the static pressure signal are input. A correlation calculation unit that calculates a cross-correlation coefficient with motion and an auto-correlation coefficient of fluctuation of the static pressure signal, and an output of the correlation calculation unit is input, and the cross-correlation coefficient and the autocorrelation coefficient A ratio calculation unit that calculates a ratio, an output of the ratio calculation unit, and an output of the variance calculation unit A determination unit to which the variance of the differential pressure signal is input, and the determination unit compares the variance of the differential pressure signal with a predetermined reference value to determine whether both of the two pressure guiding tubes are clogged. It is determined, and it is determined whether one of the two pressure guiding pipes is clogged from the ratio value output by the ratio calculation unit. It is possible to deal with clogging in all modes.
[0019]
The invention according to claim 8 is the invention according to claim 7 , wherein the determination unit includes a side of the pressure guiding tube that has received the static pressure signal when the input ratio is 1 or a value close to 1. It is determined that the pressure guiding tube on the opposite side is clogged, and when the input ratio is 0 or close to 0, it is determined that the pressure guiding tube on the side that has received the static pressure signal is clogged. It is a thing. The clogging of the pressure guiding tube can be detected reliably.
[0021]
Reference numeral 5 denotes a pipe blockage detection device, to which a high-pressure side static pressure and differential pressure signal detected by the differential pressure transmitter 4 is input. The pipe blockage detecting device 5 includes a dispersion calculation unit 52, a ratio calculation unit 53, and a determination unit 54. The variance calculation unit 52 includes a swing calculation unit 521 and a square sum calculation unit 522.
[0022]
The static pressure data calculated in the differential pressure transmitter 4 and the average value of the differential pressure data for a predetermined time are input to the swing calculation unit 521 in the dispersion calculation unit 52. The swing calculation unit 521 calculates and outputs the swing of the difference between adjacent static pressure and differential pressure data based on the following equations (1) and (2).
i-th difference圧揺Dochi _{_{_{F Δ P, i = ΔP i}}} -ΔP i-1 ··· (1)
i-th static pressure fluctuation value F _{PH, i} = PH _i −PH _i−1 (2)
However,
ΔP _i , ΔP _i-1 : i, (i-1) th differential pressure data PH _i , PH _i-1 : i, (i-1) th differential pressure data
This difference圧揺Dochi F _delta _P, the static圧揺Dochi F _PH is (are omitted elements i times) is inputted to the square sum calculating section 522. The sum-of-squares calculation unit 522 squares each of the n swing values based on the following equations (3) and (4), and adds these squared values. This added value is called dispersion of the differential pressure signal and the static pressure signal , respectively.
[0024]
[Expression 2]

Note that “n” below Σ in the above equations (3) and (4) indicates that n is added, and the differential value or static pressure fluctuation value F _ΔP , which is normally continued in time series, It is added to the square of the F _PH.
[0025]
The output of the square sum calculating section 522 is input to the ratio calculation unit 53, the ratio R _V of the variance of the following (5) dispersing the static pressure signal of the differential pressure signal based on the expression is calculated.
R _V = V _ΔP / V _PH (5)
Square sum V _{[Delta] P} of the differential pressure fluctuation of the ratio R _V and the square sum calculating section 522 is output is input to the determination unit 54, or is clogged with which impulse line from these inputs is determined.
[0026]
Next, the operation of the determination unit 54 will be described. When the

pressure guiding pipes

31 and 32 are clogged, it becomes difficult for the oscillation having a high frequency to be transmitted to the differential pressure transmitter 4. That is, the clogging of the

pressure guiding tubes

31 and 32 can be expressed by a first-order lag system with a time constant T. As the clogging increases, the time constant T also increases. Further, the capsule (pressure-sensitive portion) of the differential pressure transmitter 4 and the amplifier that amplifies the pressure signal can also be expressed by a first-order lag system with a time constant T _trans . From this, it can be seen that if any one of the

pressure guiding tubes

31 and 32 is clogged, the fluctuation of the static pressure on the clogged side becomes small.
[0027]
The determination unit 54 compares the square sum of the differential pressure fluctuation output from the square sum calculation unit 522 with a normal value (a state in which neither of the

pressure guide tubes

31 and 32 is clogged), and compares the

pressure guide tubes

31 and 32. Determine if both are clogged. If both of the pressure guiding pipes are clogged, the fluctuation with a high differential pressure frequency becomes small, so that the square sum of the fluctuations of the differential pressure, that is, the dispersion becomes small. From this, it can be determined whether or not both pressure guiding tubes are clogged.
[0028]
As described above, when the high pressure side guiding tube 31 is clogged, the static pressure fluctuation _{FPH in the} expression (2) becomes close to zero, so that the dispersion of the static pressure fluctuation in the expression (4) becomes small, the ratio _{R V} of the dispersion increases. Further, the static pressure fluctuation of the impulse line 32 of the low pressure side is clogged low voltage side so close to zero, the static pressure fluctuation F _PH and the differential pressure fluctuation F _{[Delta] P} of the high-pressure side is substantially equal. Therefore, the ratio _{R V} of dispersion of the (5) approaches 1. In this way, it is possible to detect whether the one side impulse line from the dispersion of the ratio R _V jammed.
[0029]
That is, the pressure distribution V _ΔP is compared with the normal value, and from the value of the differential pressure distribution V _ΔP and the dispersion ratio R _V of the static pressure distribution V _PH , which pressure guiding tube is clogged? Alternatively, it can be determined whether both pressure guiding tubes are clogged. Even if the pressure guiding tube 31 on the high pressure side is clogged, the variance V _{ΔP of the} differential pressure may show a normal value. Therefore, it is determined whether one of the pressure guiding tubes is clogged using the dispersion ratio R _V.
[0030]
In this embodiment, the high-pressure side static pressure is used, but the low-pressure side static pressure may be used. When the low-pressure side static pressure is used, the differential pressure distribution V _ΔP and the static pressure distribution V _PH become substantially equal when the high-pressure side pressure guiding tube is clogged. Further, when the pressure guiding tube on the low pressure side is clogged, the dispersion of the static pressure is reduced, and the dispersion ratio is increased. In this way, it can be determined which pressure guiding tube is clogged.
[0031]
FIG. 2 shows another embodiment of the present invention. In addition, the same code | symbol is attached | subjected to the same element as FIG. 1, and description is abbreviate | omitted. In FIG. 2, reference numeral 6 denotes a pipe blockage detection device, which includes a dispersion calculation unit 62, a swing calculation unit 63, a correlation calculation unit 64, a ratio calculation unit 65, and a determination unit 66. The variance calculation unit 62 includes a swing calculation unit 621 and a square sum calculation unit 622.
[0032]
The differential pressure signal calculated in the differential pressure transmitter 4 is input to the dispersion calculation unit 62. Similar to the dispersion calculation unit 52, the variance calculation unit 62 calculates the differential pressure fluctuation value F _ΔP by the above equation (1), and calculates the square sum of the differential pressure fluctuations, that is, the variance by the above equation (3). And output to the determination unit 66.
[0033]
The differential pressure signal and the static pressure signal are also input to the swing calculation unit 63. The swing calculation unit 63 calculates a differential pressure swing value F _ΔP and a static pressure swing value F _PH based on the equations (1) and (2) and outputs the calculated values to the correlation calculation unit 64. Correlation calculating unit 64 calculates a cross-correlation coefficient C ₁ of the difference圧揺Dochi F _{[Delta] P} and the electrostatic圧揺Dochi F _PH in accordance with the following equation (6), static on the basis of the following equation (7)圧揺computing the autocorrelation coefficients _{C 2} of Dochi _{F PH.}
[0034]
[Equation 3]

Note that “n” under Σ represents that a correlation coefficient is calculated for n fluctuation values.
[0035]
The two correlations calculated by the correlation calculation unit 64 are input to the ratio calculation unit 65. The ratio calculation unit 65 calculates two correlation ratios _{RC according} to the following equation (8), and outputs them to the determination unit 66.
[Expression 4]

[0036]
Next, the operation of the determination unit 66 will be described. The determination unit 66 compares the differential pressure variance V _{ΔP with} that of the normal value to determine whether both of the

pressure guiding tubes

31 and 32 are clogged. This determination procedure is the same as that in the embodiment of FIG.
[0037]
Next, the determination unit 66 determines whether one of the

pressure guiding tubes

31 and 32 is clogged based on the correlation ratio _RC that is the output of the ratio calculation unit 65. When only the low pressure side pressure guiding tube 32 is clogged, the low pressure side static pressure fluctuation is close to zero, and the differential pressure fluctuation is close to the high pressure side static pressure fluctuation. Therefore, the equation (6) is the difference圧揺value of cross-correlation coefficient C ₁ of the dynamic and static pressure swing becomes a value close to the autocorrelation C ₂ static pressure fluctuation of the equation (7), these The ratio _RC takes a value close to 1.
[0038]
On the other hand, when only the high pressure side pressure guiding tube 31 is clogged, the differential pressure fluctuation takes a value close to the low pressure side static pressure fluctuation. Therefore, there is no association between the static pressure fluctuation and the differential pressure fluctuation of the high pressure side, the high pressure side of the static pressure fluctuation and the cross-correlation coefficient C ₁ of the differential pressure fluctuation is close to zero, in some cases Negative value. Thus, by calculating the ratio of the correlation coefficient, it is possible to detect clogging of the high pressure side or low pressure side pressure guiding tube.
[0039]
In this embodiment, as in the embodiment of FIG. 1, a low-pressure side pressure can be used as the static pressure. In this case, when the high-pressure side pressure guiding tube 31 is clogged, the differential pressure fluctuation and the static pressure fluctuation are approximately the same, and the ratio _RC takes a value close to 1. In contrast, the value of the close correlation coefficient C ₁ is zero because the relevance is eliminated between the low pressure side of the impulse line 32 is clogged when the differential pressure fluctuation and static swing, also the ratio R _C Take similar values.
[0040]
Moreover, the (1), (2) the differential pressure fluctuation F _{[Delta] P, i,} the static pressure swing _{F PH,} calculation of _i is is possible to use the last two differential pressure data or static data desirable.
[0041]
Furthermore, if only clogging of one of the high pressure side pressure guiding tube 31 and the low pressure side pressure guiding tube 32 is detected, it is necessary to compare the differential pressure variance VΔP in the equation (3) with the reference value in the normal state. Instead, it is only necessary to examine the value of the dispersion ratio RV in the equation (5) or the correlation coefficient ratio RC in the equation (8).
【The invention's effect】
As is clear from the above description, the following effects can be expected according to the present invention.
According to the first aspect of the present invention, a differential pressure signal between two pressure guide tubes and a static pressure signal of one of the pressure guide tubes are input, and the differential pressure signal and the static pressure signal are input. A dispersion computing unit that computes each oscillation based on a difference between adjacent data and computes a sum of squares of these differential pressure oscillations and a square sum of static pressure oscillations, and outputs the variance as a variance The output of the unit is input, the ratio calculating unit that calculates and outputs the ratio of the variance of the differential pressure signal and the variance of the static pressure signal, and the output of the ratio calculating unit is input, and the pressure guiding tube is input from this input value And a determination unit that determines clogging of the pressure guide, and the determination unit determines which pressure guiding tube is clogged.
[0042]
Since it is a method to determine which pressure guiding tube is clogged by detecting only the dispersion ratio change, which is a statistic due to clogging of the pressure guiding tube, operation of the plant such as the flow range of the actual process and the magnitude of fluctuation There is an effect that accurate detection can be performed regardless of conditions.
[0043]
According to a second aspect of the present invention, in the first aspect of the invention, the determination unit takes the static pressure signal in the pressure guiding tube when the input ratio is 1 or a value close to 1. It is determined that the pressure guiding tube on the opposite side is clogged, and it is determined that the pressure guiding tube on the side that has received the static pressure signal is clogged when the input ratio is considerably larger than 1. I did it. Since the ratios are simply compared, there is an effect that clogging of the pressure guiding tube can be detected easily and reliably.
[0045]
According to the third aspect of the present invention, two static pressure signal of the differential pressure signal and either of the impulse line between the impulse line is input, each of the signals based on the difference between these adjacent data A rocking calculation unit that calculates and outputs the rocking of the sway, and a correlation calculation that calculates the cross-correlation coefficient of these two signals and the autocorrelation coefficient of the static pressure signal by inputting the output of the rocking calculation unit And the output of the correlation calculation unit, the ratio calculation unit for calculating and outputting the ratio of the cross-correlation coefficient and the autocorrelation coefficient, and the output of the ratio calculation unit are input, the input value And a determination unit for determining clogging of the pressure guiding tube. The determination unit determines clogging of the pressure guiding tube.
[0046]
Since it is a method to determine which pressure pipe is clogged by detecting only the ratio change of the correlation coefficient, which is a statistic due to clogging of the pressure pipe, the plant's flow rate range of the actual process, fluctuation of the fluctuation, etc. There is an effect that accurate detection can be performed regardless of the operating conditions.
[0047]
According to a fourth aspect of the present invention, in the third aspect of the present invention, the determination unit takes the static pressure signal in the pressure guiding tube when the input ratio is 1 or a value close to 1. It is determined that the pressure guiding tube on the opposite side is clogged, and when the input ratio is 0 or close to 0, it is determined that the pressure guiding tube on the side that has received the static pressure signal is clogged. I tried to do it. Since the ratios are simply compared, there is an effect that clogging of the pressure guiding tube can be detected easily and reliably.
[0048]
According to the fifth aspect of the present invention, the differential pressure signal between the two pressure guiding pipes and the static pressure signal of one of the pressure guiding pipes are input, and each is based on the difference between adjacent data of these signals. A dispersion calculation unit that calculates the sum of squares of the differential pressure fluctuations and the square sum of the static pressure fluctuations and outputs the variance as a variance, and an output of the dispersion calculation unit is input, A ratio calculator that calculates a ratio of signal variance and static pressure signal variance; and a determination unit that receives the output of the ratio calculator and the variance of the differential pressure signal output by the variance calculator. The determination unit compares the variance of the differential pressure signal with a predetermined reference value to determine whether both of the two pressure guiding tubes are clogged, and determines the 2 from the ratio value output by the ratio calculation unit. To determine whether one of the pressure tubes is clogged It was.
[0049]
Since it is a method to determine which pressure pipes are clogged by detecting only dispersion and ratio change, which is a statistic due to clogging of the pressure guide pipes, the actual flow rate range of the process and the magnitude of fluctuations, etc. There is an effect that accurate detection can be performed regardless of operating conditions. Further, when only one of the pressure guiding pipes is clogged, there is an effect that clogging can be accurately detected with respect to clogging in all modes when both of the pressure guiding pipes are clogged.
[0050]
According to a sixth aspect of the present invention, in the fifth aspect of the present invention, the determination unit takes the static pressure signal in the pressure guiding tube when the input ratio is 1 or a value close to 1. It is determined that the pressure guiding tube on the opposite side is clogged, and it is determined that the pressure guiding tube on the side that has received the static pressure signal is clogged when the input ratio is considerably larger than 1. I did it. Since the dispersion and its ratio are only compared with a predetermined value, there is an effect that the clogging of the pressure guiding tube can be detected easily and reliably.
[0052]
According to the seventh aspect of the present invention, the differential pressure signal between the two pressure guiding pipes and the static pressure signal of one of the pressure guiding pipes are input, and between the differential pressure signal and the adjacent data of the static pressure signal. A dispersion calculating unit that calculates each oscillation based on the difference, calculates a square sum of the differential pressure oscillations and a square sum of the static pressure oscillations, and outputs the result as variance; the differential pressure signal and the static pressure signal Is inputted, and the fluctuation calculation unit that calculates and outputs the fluctuation of the signal between the adjacent data, and the output of the fluctuation calculation part are inputted, the fluctuation of the differential pressure signal and the static pressure signal A correlation calculation unit that calculates a cross-correlation coefficient with fluctuation and an auto-correlation coefficient of fluctuation of the static pressure signal, and an output of the correlation calculation part are input, and the cross-correlation coefficient and the auto-correlation coefficient The ratio calculator that calculates the ratio of the output, the output of the ratio calculator, and the output of the variance calculator A determination unit to which the variance of the differential pressure signal is input, and the determination unit compares the variance of the differential pressure signal with a predetermined reference value to determine whether both of the two pressure guiding tubes are clogged. And determining whether one of the two pressure guiding tubes is clogged from the ratio value output by the ratio calculation unit.
[0053]
Since it is a method to determine which pressure pipe is clogged by detecting only the variance and correlation coefficient ratio change that are statistics due to clogging of the pressure pipe, the flow range of the actual process and the magnitude of fluctuation etc. There is an effect that accurate detection can be performed regardless of the operating conditions of the plant. Further, when only one of the pressure guiding pipes is clogged, there is an effect that clogging can be accurately detected with respect to clogging in all modes when both of the pressure guiding pipes are clogged.
[0054]
According to an eighth aspect of the present invention, in the seventh aspect of the invention, the determination unit takes the static pressure signal in the pressure guiding tube when the input ratio is 1 or a value close to 1. It is determined that the pressure guiding tube on the opposite side is clogged, and when the input ratio is 0 or close to 0, it is determined that the pressure guiding tube on the side that has received the static pressure signal is clogged. I tried to do it. Since only the ratio between the variance and the correlation coefficient is compared with a predetermined value, there is an effect that the clogging of the pressure guiding tube can be detected easily and reliably.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing an embodiment of the present invention.
FIG. 2 is a block diagram showing another embodiment of the present invention.
FIG. 3 is a configuration diagram of a conventional pipe blockage detecting device.
[Explanation of symbols]
31 and 32 Pressure guiding pipe 4 Differential pressure transmitter 5 and 6 Pipe

blockage detection devices

52 and 62

Dispersion calculation sections

521, 621 and 63

Oscillation calculation sections

522 and 622 Square

sum calculation sections

53 and 65 Ratio calculation sections 54 and 66 Determination unit 64 Correlation calculation unit

Claims

A differential pressure signal between two pressure guiding pipes and a static pressure signal of one of the pressure guiding pipes are input, and each of these is based on a difference between adjacent data of the differential pressure signal and the static pressure signal. A dispersion calculating unit that calculates the sum of squares of these differential pressure fluctuations and the square sum of the static pressure fluctuations and outputs as a variance,
An output of the dispersion calculation unit is input, and a ratio calculation unit that calculates and outputs a ratio of dispersion of the differential pressure signal and dispersion of the static pressure signal;
An apparatus for detecting a blockage of a conduit, comprising: an output of the ratio calculation unit; and a determination unit that determines clogging of the pressure guiding tube from the input value.

The determination unit determines that the pressure guide tube on the opposite side of the pressure guide tube from which the static pressure signal is taken is clogged when the input ratio is 1 or a value close to 1, and the input is performed. 2. The pipe blockage detecting device according to claim 1, wherein when the ratio is considerably larger than 1, it is determined that the pressure guiding tube on the side where the static pressure signal is taken out of the pressure guiding tubes is clogged. .

The differential pressure signal between the two pressure guiding tubes and the static pressure signal of one of the pressure guiding tubes are input, and the fluctuations of the respective signals based on the difference between the adjacent data are calculated and output. A dynamic calculation unit;
An output of the swing calculation unit is input, and a correlation calculation unit for calculating a cross-correlation coefficient of these two signals and an autocorrelation coefficient of the static pressure signal,
An output of the correlation calculation unit is input, a ratio calculation unit that calculates and outputs a ratio of the cross-correlation coefficient and the autocorrelation coefficient; and
An apparatus for detecting a blockage of a conduit, comprising: an output of the ratio calculation unit; and a determination unit that determines clogging of the pressure guiding tube from the input value.

The determination unit determines that the pressure guiding tube on the side opposite to the side where the static pressure signal is taken is clogged in the pressure guiding tube when the input ratio is 1 or a value close to 1, and the input is performed. 4. The pipeline blockage detection according to claim 3 , wherein when the ratio is 0 or close to 0, it is determined that the pressure guiding tube on the side where the static pressure signal is taken out of the pressure guiding tubes is clogged. apparatus.

The differential pressure signal between the two pressure guiding tubes and the static pressure signal of one of the pressure guiding tubes are input, and the respective fluctuations based on the difference between adjacent data of these signals are calculated and these differential pressures are calculated. A dispersion calculation unit that calculates a sum of squares of oscillation and a square of static pressure oscillations and outputs as a variance;
An output of the dispersion calculation unit is input, and a ratio calculation unit that calculates a ratio of dispersion of the differential pressure signal and dispersion of the static pressure signal;
An output of the ratio calculation unit and a determination unit to which the variance of the differential pressure signal output by the variance calculation unit is input;
The determination unit compares the variance of the differential pressure signal with a predetermined reference value to determine whether both of the two pressure guiding tubes are clogged, and determines the two values based on the ratio value output by the ratio calculation unit. A pipe blockage detecting device characterized in that it is determined whether any of the pressure guiding pipes is clogged.

The determination unit determines that the pressure guiding tube on the side opposite to the side where the static pressure signal is taken is clogged in the pressure guiding tube when the input ratio is 1 or a value close to 1, and the input is performed. 6. The pipe blockage detecting device according to claim 5 , wherein when the ratio is considerably larger than 1, it is determined that the pressure guiding tube on the side of the pressure guiding tube that has received the static pressure signal is clogged.

The differential pressure signal between the two pressure guiding pipes and the static pressure signal of either one of the pressure guiding pipes are input, and the respective fluctuations based on the difference between the adjacent data of the differential pressure signal and the static pressure signal are calculated. And a variance computing unit that computes the square sum of the differential pressure fluctuations and the square sum of the static pressure fluctuations and outputs the result as a variance,
An oscillation calculation unit that receives the differential pressure signal and the static pressure signal, calculates and outputs oscillation of a signal between the adjacent data , and
Correlation calculation for calculating the cross-correlation coefficient between the fluctuation of the differential pressure signal and the fluctuation of the static pressure signal and the autocorrelation coefficient of the fluctuation of the static pressure signal when the output of the fluctuation calculation unit is input And
The output of this correlation calculation unit is input, a ratio calculation unit that calculates the ratio of the cross-correlation coefficient and the autocorrelation coefficient;
An output of the ratio calculation unit and a determination unit to which the variance of the differential pressure signal output by the variance calculation unit is input;
The determination unit compares the variance of the differential pressure signal with a predetermined reference value to determine whether both of the two pressure guiding tubes are clogged, and determines the two values based on the ratio value output by the ratio calculation unit. A pipe blockage detecting device characterized in that it is determined whether any of the pressure guiding pipes is clogged.

The determination unit determines that the pressure guiding tube on the side opposite to the side where the static pressure signal is taken is clogged in the pressure guiding tube when the input ratio is 1 or a value close to 1, and the input is performed. 8. The pipe blockage detection according to claim 7 , wherein when the ratio is 0 or close to 0, it is determined that the pressure guiding tube of the pressure guiding tube which has received the static pressure signal is clogged. apparatus.