JP4240599B2 - Water supply equipment - Google Patents

Description

【００２６】
ただし、ｌ₂ ：動作点Ｐ₃ の軸動力（ｐ．ｕ．）＝Ｌ₂ ／Ｌ_N （ｐ．ｕ．）
Ｌ₂ ：動作点Ｐ₃ の軸動力（ｋＷ）
Ｌ_N ：定格軸動力（ｋＷ）
ｈ_pomax ：設定最大締め切り揚程（ｐ．ｕ．）＜（ｈ_a ＋ｈ_k ）（ｐ．ｕ．）
ｈ_a ：実揚程（ｐ．ｕ．）＝Ｈ_a ／Ｈ_N （ｐ．ｕ．）
ｈ_k ：管端圧力（ｐ．ｕ．）＝Ｈ_K ／Ｈ_N （ｐ．ｕ．）
Ｈ_a ：実揚程（ｍ）
Ｈ_k ：管端圧力（ｍ）
Ｈ_N ：電動ポンプ１２Ａ，１２Ｂの定格揚程（ｍ）
η_qB：バイパス流量ｑ_B （ｐ．ｕ．）のときの電動ポンプ効率（ｐ．ｕ．）
ｑ_B ：第１締め切り揚程制御におけるバイパス流量（ｐ．ｕ．）
【００２７】
この第（１）式で与えられる軸動力から、バイパス管揚程損失、水に与えた仕事分を差し引いた軸動力が、電動ポンプ１２Ａ，１２Ｂ内で消費されることになるので、バイパス流量ｑ_B が小さすぎると、電動ポンプ１２Ａ，１２Ｂ内の水、羽根車、パッキング、軸受け部、メカニカルシール、電動機コイルなどの温度が上昇することになる。
そして、電動ポンプ毎に各部の温度上昇が規定値内に収まるように、軸動力とバイパス流量の関係を実験値や試験値で求め、この求めた軸動力とバイパス流量の関係を満足するように許容最大締め切り揚程ｈ_pmaxを求め、設定最大締め切り揚程ｈ_pomax を決定する。
【００２８】
このようにして求めた許容最大締め切り揚程ｈ_pmaxにおける動作点、または設定最大締め切り揚程ｈ_pomax における動作点Ｐ₃ は、逆止め弁１３Ａ，１３Ｂを閉成させたままとする動作点である。
そして、設定最大締め切り揚程ｈ_pomax は電動ポンプ１２Ａ，１２Ｂを連続運転できるものの、許容最大締め切り揚程ｈ_pmaxは限られた時間だけ電動ポンプ１２Ａ，１２Ｂを運転できる。
【００２９】
また、第２締め切り揚程制御になると、設定最小締め切り揚程はｈ_poとなる。
この設定最小締め切り揚程ｈ_poは、第（２）式を満足する値で、電動ポンプ１２Ａ，１２Ｂのメカニカルシールを潤滑できて摩擦抵抗が最小となる許容最小締め切り揚程ｈ_pmin に可能な限り近い値に設定する。
【００３０】
【数２】

【００３１】
ただし、ｈ_pmax：許容最大締め切り揚程（ｐ．ｕ．）＜（ｈ_a ＋ｈ_k ）（ｐ．ｕ．）
ｈ_po：設定最小締め切り揚程（ｐ．ｕ．）
ｈ_pmin：許容最小締め切り揚程（ｐ．ｕ．）
なお、許容最小締め切り揚程ｈ_pmin は、電動ポンプ１２Ａ，１２Ｂのメカニカルシールを潤滑できて摩擦抵抗が最小となる締め切り揚程である。
第（２）式で与えられる第２締め切り揚程制御になると、低速度で電動ポンプ１２Ａ，１２Ｂが運転され、静粛かつ省エネルギー運転となる。
【００３２】
さらに、流量検出手段の小流量検出について説明する。
図８において、小流量運転を（ｈ−ｑ）_min とすれば、このとき電動ポンプ１２Ａ，１２Ｂが与える締め切り揚程は、ｈ−ｑ特性を電動ポンプ１２Ａ，１２Ｂの速度と流量の二次式で近似させた場合、第（３）式のように表すことができる。
【００３３】
【数３】

【００３４】
ただし、ａ：電動ポンプ１２Ａ，１２Ｂの定数
ｎ：電動ポンプ１２Ａ，１２Ｂの速度（ｐ．ｕ．）＝Ｎ／Ｎ_N （ｐ．ｕ．）
Ｎ：電動ポンプ１２Ａ，１２Ｂの速度（ｒｐｍ）
Ｎ_N ：電動ポンプ１２Ａ，１２Ｂの定格速度（ｒｐｍ）
ｈ_a ：実揚程（ｐ．ｕ．）
ｈ_k ：管端圧力（ｐ．ｕ．）
ｈ_omin ：補償揚程（ｐ．ｕ．）
ｈ_su：ポンプ押し込み揚程（ｐ．ｕ．）＝Ｈ_su／Ｈ_N （ｐ．ｕ．）
Ｈ_su：ポンプ押し込み揚程（逆止め弁１１の入り側）（ｍ）
Ｈ_N ：電動ポンプ１２Ａ，１２Ｂの定格揚程（ｍ）
ｈ_suc ：逆止め弁１１の固定損失揚程（ｐ．ｕ．）＝Ｈ_suc ／Ｈ_N （ｐ．ｕ．）
Ｈ_suc ：逆止め弁１１の固定損失揚程（ｐ．ｕ．）
【００３５】
この第（３）式の（ｈ_su−ｈ_suc ）は、実効押し込み揚程であり、図６に示すように、圧力検出器１８が水道管側に設けられた場合、検出値としての圧力ｈ_suと、実際に測定された固定損失揚程ｈ_suc との差によって得られる。
したがって、逆止め弁１３Ａ，１３Ｂよりも下流の給水本管２の流量が最小流量ｑ_min になったのを検出することができる。
【００３６】
図９は図６および図７に示した給水装置における切換制御部のフローチャートである。
図９において、ＳＴ１〜ＳＴ１０はステップを示す。
【００３７】
次に、切換制御部の制御、給水について説明する。
なお、図示を省略した蛇口が開放され、給水している状態で、比較器２１ｓは、流量が最小流量ｑ_min よりも多い第２信号を出力している。
まず、切換制御部２１ｔは、比較器２１ｓの出力が最小流量ｑ_min 以下の第１信号であるかを判定し（ステップＳＴ１）、比較器２１ｓの出力が最小流量ｑ_min 以下の第１信号でなければ、すなわち流量が最小流量ｑ_min よりも多い第２信号である給水状態であれば、選択スイッチ２１ｃ，２１ｋを接点ａ側へ切り換えるとともに、電動弁１６Ａ，１６Ｂを閉成し（ステップＳＴ２）、ステップＳＴ１へ戻る。
【００３８】
このように選択スイッチ２１ｃ，２１ｋが切換制御部２１ｔの制御によって接点ａ側になると、圧力検出器２０の圧力ｈ_i を検出値、推定末端圧力設定器２１ａの推定末端圧力ｈ_s を設定値とし、両者の差をゼロとするように比例積分制御器２１ｄの出力が変化し、公知の推定末端圧一定制御となる。
したがって、図８の推定末端圧一定制御曲線Ａ上の動作点Ｐ₁ と、動作点Ｐ₂ のとの間を移動する推定末端圧力一定制御となる。
【００３９】
そして、全ての蛇口が閉じられることにより、流量が最小流量ｑ_min 以下になると、比較器２１ｓから流量が最小流量ｑ_min 以下の第１信号が出力される。
このように比較器２１ｓから第１信号が出力されると、切換制御部２１ｔは、比較器２１ｓからの信号が第１信号であることを確認した後（ステップＳＴ１）、タイマをセットする（ステップＳＴ３）。
そして、タイマを参照して第１所定時間、例えば６０秒が経過したかを判定し（ステップＳＴ４）、６０秒経過していなければ、比較器２１ｓからの第１信号が継続しているかを判定する（ステップＳＴ５）。
【００４０】
このステップＳＴ５の判定で、比較器２１ｓからの第１信号が継続していなければ、ステップＳＴ１へ戻り、比較器２１ｓからの第１信号が継続していれば、ステップＳＴ４へ戻る。
そして、ステップＳＴ４の判定で６０秒が経過していれば、選択スイッチ２１ｃを接点ｂ側へ切り換え、電動弁１６Ａ，１６Ｂを開放するとともに、タイマをセットする（ステップＳＴ６）。
【００４１】
このように選択スイッチ２１ｃが切換制御部２１ｔの制御によって接点ｂ側になると、比例積分制御器２１ｄの出力を検出値、第１締め切り揚程設定器２１ｉの設定最大締め切り揚程ｈ_pomax を設定値とし、両者の差をゼロとするように比例積分制御器２１ｄの出力が変化する第１締め切り揚程制御となるので、逆止め弁１３Ａ，１３Ｂはゆっくりと下流の給水配管１の圧力を保ちながら給水分岐管３Ａ，３Ｂを閉じ、電動ポンプ１２Ａ，１２Ｂから吐出される水は、バイパス管１５Ａ，１５Ｂを介して電動ポンプ１２Ａ，１２Ｂの上流に還流する。
【００４２】
そして、切換制御部２１ｔは、比較器２１ｓからの第１信号が継続しているかを判定し（ステップＳＴ７）、比較器２１ｓからの第１信号が継続していなければ、ステップＳＴ２へ戻り、比較器２１ｓからの第１信号が継続していれば、タイマを参照して第２所定時間、例えば３０分が経過したかを判定する（ステップＳＴ８）。
【００４３】
このステップＳＴ８の判定で、３０分が経過していなければ、ステップＳＴ７へ戻り、３０分間が継続していれば、選択スイッチ２１ｋを接点ｂ側へ切り換え（ステップＳＴ９）、比較器２１ｓからの信号が第２信号になるのを待機する（ステップＳＴ１０）。
このように選択スイッチ２１ｃ，２１ｋが切換制御部２１ｔの制御によって接点ｂ側になると、比例積分制御器２１ｄの出力を検出値、第２締め切り揚程設定器２１ｊの設定最小締め切り揚程ｈ_poを設定値とし、両者の差をゼロとするように比例積分制御器２１ｄの出力が変化する第２締め切り揚程制御となるので、電動ポンプ１２Ａ，１２Ｂから吐出される水は、バイパス管１５Ａ，１５Ｂを介して電動ポンプ１２Ａ，１２Ｂの上流に還流する。
【００４４】
そして、切換制御部２１ｔは、比較器２１ｓからの信号が第２信号になると（ステップＳＴ１０）、ステップＳＴ２へ戻る。
【００４５】
上述したように、本出願人が先に提案した給水装置によれば、電動ポンプ１２Ａ，１２Ｂは停止することなく回転し、すなわち発停を繰り返さず、給水時も低速回転数から所定の回転数へ急峻に立ち上がるので、所定の回転数への立ち上がり時の騒音が小さくなり、迅速な給水に対応することができるとともに、電動ポンプ１２Ａ，１２Ｂが凍結によって損傷するのを防止することができる。
そして、電動ポンプ１２Ａ，１２Ｂは発停を繰り返さずに回転しているので、電動ポンプ１２Ａ，１２Ｂのメカニカルシールおよび軸受けの寿命が長くなるため、電動ポンプ１２Ａ，１２Ｂのメインテナンス費用を低減させることができる。
【００４６】
さらに、第１締め切り揚程制御になると、逆止め弁１３Ａ，１３Ｂをソフトに閉成させて保圧するので、ウォーターハンマによる騒音の発生を防止することができ、圧力タンクが不要になったり、圧力タンクを小形化できるため、給水装置をコンパクトに構成することができる。
また、電動ポンプ１２Ａ，１２Ｂの回転数が第１締め切り揚程制御よりも低速回転数の第２締め切り揚程制御で長期の待機状態になるので、電動ポンプ１２Ａ，１２Ｂを連続運転させているにもかかわらず、給水していないときのランニングコストを、電動ポンプ１２Ａ，１２Ｂを停止させる場合に匹敵する程の安価にすることができるとともに、静粛な運転となる。
【００４７】
そして、絞り弁１７Ａ，１７Ｂをバイパス管１５Ａ，１５Ｂに設けたので、バイパス流量ｑ_B を調整することができるとともに、バイパス管１５Ａ，１５Ｂによる還流路に汎用性を持たせることができる。
さらに、推定末端圧一定制御で給水するときはバイパス管１５Ａ，１５Ｂを閉成して還流をなくしたので、効率よく給水することができる。
【００４８】
【発明が解決しようとする課題】
上述した本出願人が先に提案した給水装置は、締め切り運転状態における電動ポンプ１２Ａ，１２Ｂの軸動力が全て電動ポンプ１２Ａ，１２Ｂ内で消費されて水温を上昇させるため、また、締め切り運転状態における電動ポンプ１２Ａ，１２Ｂの吐出側と吸水側とを接続する全長がバイパス管１５Ａ，１５Ｂの長さで短いため、水の熱を有効に放熱させて電動ポンプ１２Ａ，１２Ｂの電動機巻線、軸受部およびメカニカルシールの温度上昇を低く抑えることに限界があり、電動ポンプ１２Ａ，１２Ｂの寿命が短くなるという不都合があった。
【００４９】
この発明は、上記した不都合を解消するためになされたもので、電動機巻線、軸受部およびメカニカルシールの温度上昇を低く抑えて電動ポンプの寿命を長くすることのできる給水装置を提供するものである。
【００５０】
この発明は、並列に配設された電動ポンプの下流の各給水配管に逆止め弁が配設され、各電動ポンプよりも下流で、各逆止め弁よりも上流の各給水配管をバイパス管でその電動ポンプの上流の給水配管に連通させ、推定末端圧一定制御部または吐出圧一定制御部で各電動ポンプを停止させることなく回転させて給水する給水装置において、各電動ポンプよりも下流で、各逆止め弁よりも上流の各給水配管を各バイパス管でその電動ポンプ以外の上流の給水配管に連通させたものである。
【００５１】
または、電動ポンプよりも下流で、逆止め弁よりも上流の給水配管をバイパス管でその電動ポンプの上流の給水配管に連通させたその電動ポンプよりも上流の給水配管に、その電動ポンプ以外の電動ポンプよりも下流で、逆止め弁よりも上流の給水配管をバイパス管で少なくとも１つ連通させ、その電動ポンプよりも上流の給水配管に連通されていない、電動ポンプよりも下流で、逆止め弁よりも上流の給水配管をバイパス管でその電動ポンプ以外の上流の給水配管に連通させたものである。
【００５２】
または、電動ポンプよりも下流で、逆止め弁よりも上流の隣り合う給水配管を第１バイパス管で連通させ、電動ポンプよりも上流の隣り合う給水配管を第２バイパス管で連通させ、第１バイパス管と第２バイパス管とを第３バイパス管で連通させるとともに、給水配管と第３バイパス管との間に第１バイパス管に逆止め弁を配設し、各電動ポンプの吸い込み量と第２バイパス管から各電動ポンプの上流の給水配管への流入量とを異ならせるように第２バイパス管を構成したものである。
【００５３】
または、電動ポンプよりも下流で、逆止め弁よりも上流の隣り合う給水配管を第１バイパス管で連通させ、電動ポンプよりも上流の隣り合う給水配管を第２バイパス管で連通させるとともに、第１バイパス管と第２バイパス管とを第３バイパス管で連通させ、給水配管と第３バイパス管との間に第１バイパス管に逆止め弁を配設するとともに、第２バイパス管に絞り弁を配設したものである。
【００５４】
【発明の実施の形態】
以下、この発明の実施形態を図に基づいて説明する。
図１はこの発明の第１実施形態である給水装置の要部を示すブロック図であり、図示を省略した部分は、図６および図７と同様に構成されている。
図１において、４は受水槽を示し、給水分岐管３Ａ，３Ｂの一端側が接続されている。
【００５５】
そして、バイパス管１５Ａは、電動ポンプ１２Ａよりも下流で、逆止め弁１３Ａよりも上流の給水分岐管３Ａと、電動ポンプ１２Ｂよりも上流の給水分岐管３Ｂとを連通させている。
また、バイパス管１５Ｂは、電動ポンプ１２Ｂよりも下流で、逆止め弁１３Ｂよりも上流の給水分岐管３Ｂと、電動ポンプ１２Ａよりも上流の給水分岐管３Ａとを連通させている。
Ｓは給水分岐管３Ａとバイパス管１５Ｂとの接続点、Ｔは給水分岐管３Ｂとバイパス管１５Ａとの接続点を示す。
【００５６】
なお、電動ポンプ１２Ａの締め切り運転状態におけるバイパス管１５Ａの流量と、電動ポンプ１２Ｂの締め切り運転状態におけるバイパス管１５Ｂの流量とは、電動ポンプ１２Ａ，１２Ｂ、流量調整弁としての絞り弁１７Ａ，１７Ｂの特性が異なるため、例えば接続点Ｓにおけるバイパス管１５Ｂからの流入量よりも電動ポンプ１２Ａの吸い込み量が多く、接続点Ｔにおけるバイパス管１５Ａからの流入量よりも電動ポンプ１２Ｂの吸い込み量が少なくなる。
そして、バイパス管１５Ａ，１５Ｂの一端を受水槽４に接続したので、第（３）式における圧力ｈ_suとして圧力検出器２０の圧力ｈ_i を代用すればよい。
【００５７】
この第１実施形態における各部の動作は先の説明と同様になるが、締め切り運転状態における水の流れが異なるので、以下に説明する。
この第１実施形態においては、上述したように、接続点Ｓにおけるバイパス管１５Ｂからの流入量よりも電動ポンプ１２Ａの吸い込み量が多く、接続点Ｔにおけるバイパス管１５Ａからの流入量よりも電動ポンプ１２Ｂの吸い込み量が少ないので、受水槽４およびバイパス管１５Ｂから接続点Ｓに流入する水は電動ポンプ１２Ａに吸い込まれ、バイパス管１５Ａから接続点Ｔに流入する水は電動ポンプ１２Ｂへ吸い込まれるとともに、受水槽４へ還流する。
【００５８】
また、電動ポンプ１２Ｂが吸い込む水は電動ポンプ１２Ａを通過したものであるが、バイパス管１５Ａから接続点Ｔに流入する水の一部は受水槽４へ還流するので、電動ポンプ１２Ａ、バイパス管１５Ａ、電動ポンプ１２Ｂ、バイパス管１５Ｂを循環する水は少しずつ入れ代わる。
【００５９】
上述したように、この発明の第１実施形態によれば、電動ポンプ１２Ａ，１２Ｂよりも下流で、逆止め弁１３Ａ，１３Ｂよりも上流の給水分岐管３Ａ，３Ｂをバイパス管１５Ａ，１５Ｂでその電動ポンプ１２Ａ，１２Ｂ以外の上流の給水分岐管３Ａ，３Ｂに連通させたので、電動ポンプ１２Ａ，１２Ｂの締め切り運転状態においても、受水槽４から電動ポンプ１２Ａに流入する水に熱を放熱することにより、電動ポンプ１２Ａの温度上昇を低く抑えることができる。
また、電動ポンプ１２Ａ、バイパス管１５Ａ、電動ポンプ１２Ｂ、バイパス管１５Ｂを循環する水が少しずつ入れ代わるので、入れ代わる水の放熱作用より、電動ポンプ１２Ｂの温度上昇を低く抑えることができる。
【００６０】
したがって、電動ポンプ１２Ａ，１２Ｂの電動機巻線、軸受部およびメカニカルシールの温度上昇を低く抑えることができるので、電動ポンプ１２Ａ，１２Ｂの寿命を長くすることができる。
また、電動ポンプ１２Ａ，１２Ｂの電動機巻線、軸受部およびメカニカルシールの温度上昇を低く抑えるためのバイパス管１５Ａ，１５Ｂの長さが短くて済むので、所期の目的を安価な構成で達成することができる。
【００６１】
図２はこの発明の第２実施形態である給水装置の要部を示すブロック図であり、図示を省略した部分は、図６および図７と同様に構成されている。
図２において、３Ｃは給水配管１を構成する給水分岐管を示し、給水分岐管３Ａ，３Ｂと並列に配設され、一端が給水分岐管３Ａ，３Ｂとともに受水槽４に接続されている。
１２Ｃは給水分岐管３Ｃに配設された電動ポンプ、１３Ｃは電動ポンプ１２Ｃよりも下流の給水分岐管３Ｃに配設された逆止め弁、１４Ｃは逆止め弁１２Ｃよりも下流の給水分岐管３Ｃに配設された締め切り弁を示す。
【００６２】
１５Ｃはバイパス管を示し、電動ポンプ１２Ｃよりも下流で、逆止め弁１３Ｃよりも上流の給水分岐管３Ｃと、電動ポンプ１２Ｂよりも上流の給水分岐管３Ｂとを連通させるものである。
１６Ｃはバイパス管１５Ｃに配設された電動弁を示し、前述した切換制御部２１ｔによって制御され、バイパス管１５Ｃの流路を開閉するものである。
１７Ｃはバイパス管１５Ｃに配設された流量調整弁としての絞り弁を示す。
【００６３】
そして、バイパス管１５Ａは、電動ポンプ１２Ａよりも下流で、逆止め弁１３Ａよりも上流の給水分岐管３Ａと、電動ポンプ１２Ａよりも上流の給水分岐管３Ａとを連通させている。
また、バイパス管１５Ｂは、電動ポンプ１２Ｂよりも下流で、逆止め弁１３Ｂよりも上流の給水分岐管３Ｂと、電動ポンプ１２Ａよりも上流の給水分岐管３Ａとを連通させている。
Ｕは給水分岐管３Ａとバイパス管１５Ａ，１５Ｂとの接続点、Ｖは給水分岐管３Ｂとバイパス管１５Ｃとの接続点を示す。
【００６４】
なお、電動ポンプ１２Ｂの締め切り運転状態におけるバイパス管１５Ｂの流量と、電動ポンプ１２Ｃの締め切り運転状態におけるバイパス管１５Ｃの流量とは、電動ポンプ１２Ｂ，１２Ｃ、絞り弁１７Ｂ，１７Ｃの特性が異なるため、接続点Ｕにおけるバイパス管１５Ａ，１５Ｂからの流入量よりも電動ポンプ１２Ａの吸い込み量が少なく、例えば接続点Ｖにおけるバイパス管１５Ｃからの流入量よりも電動ポンプ１２Ｂの吸い込み量が多くなる。
【００６５】
この第２実施形態における各部の動作は先の説明と同様になるが、締め切り運転状態における水の流れが異なるので、以下に説明する。
この第２実施形態においては、上述したように、接続点Ｕにおけるバイパス管１５Ａ，１５Ｂからの流入量よりも電動ポンプ１２Ａの吸い込み量が少なく、接続点Ｖにおけるバイパス管１５Ｃからの流入量よりも電動ポンプ１２Ｂの吸い込み量が多いので、バイパス管１５Ａ，１５Ｂから接続点Ｕに流入する水は電動ポンプ１２Ａへ吸い込まれるとともに、受水槽４へ還流し、受水槽４およびバイパス管１５Ｃから接続点Ｖへ流入する水は電動ポンプ１２Ｂに吸い込まれ、電動ポンプ１２Ｃは受水槽４の水を吸い込むことになる。
【００６６】
また、電動ポンプ１２Ａが吸い込む水は電動ポンプ１２Ａ，１２Ｂを通過したものであるが、バイパス管１５Ａ，１５Ｂから接続点Ｕに流入する水の一部は受水槽４へ還流するので、電動ポンプ１２Ａ、バイパス管１５Ａを循環する水は少しずつ入れ代わる。
【００６７】
上述したように、この発明の第２実施形態によれば、電動ポンプ１２Ａ，１２Ｂよりも下流で、逆止め弁１３Ａ，１３Ｂよりも上流の給水分岐管３Ａ，３Ｂをバイパス管１５Ａ，１５Ｂで電動ポンプ１２Ａの上流の給水分岐管３Ａに連通させ、電動ポンプ１２Ｃよりも下流で、逆止め弁１３Ｃよりも上流の給水分岐管３Ｃをバイパス管１５Ｃで電動ポンプ１２Ｂよりも上流の給水分岐管３Ｂに連通させたので、電動ポンプ１２Ａ〜１２Ｃの締め切り運転状態においても、受水槽４から電動ポンプ１２Ｂ，１２Ｃに流入する水に熱を放熱することにより、電動ポンプ１２Ｂ，１２Ｃの温度上昇を低く抑えることができる。
また、電動ポンプ１２Ａ、バイパス管１５Ａを循環する水は少しずつ入れ代わるので、入れ代わる水による放熱作用により、電動ポンプ１２Ａの温度上昇を低く抑えることができる。
【００６８】
したがって、電動ポンプ１２Ａ〜１２Ｃの電動機巻線、軸受部およびメカニカルシールの温度上昇を低く抑えることができるので、電動ポンプ１２Ａ〜１２Ｃの寿命を長くすることができる。
また、電動ポンプ１２Ａ〜１２Ｃの電動機巻線、軸受部およびメカニカルシールの温度上昇を低く抑えるためのバイパス管１５Ａ〜１５Ｃの長さが短くて済むので、所期の目的を安価な構成で達成することができる。
【００６９】
図３はこの発明の第３実施形態である給水装置の要部を示すブロック図であり、図示を省略した部分は、図６および図７と同様に構成されている。
図３において、１５Ｄは第１バイパス管を示し、電動ポンプ１２Ａよりも下流で、逆止め弁１３Ａよりも上流の給水分岐管３Ａと、電動ポンプ１２Ｂよりも下流で、逆止め弁１３Ｂよりも上流の給水分岐管３Ｂとを連通させるものである。１５Ｅは第２バイパス管を示し、電動ポンプ１２Ａよりも上流の給水分岐管３Ａと、電動ポンプ１２Ｂよりも上流の給水分岐管３Ｂとを連通させるものである。
１５Ｆは第３バイパス管を示し、第１バイパス管１５Ｄと、第２バイパス管１５Ｅとを連通させるものである。
【００７０】
１３Ｄは逆止め弁を示し、給水分岐管３Ａと第３バイパス管１５Ｆとの間の第１バイパス管１５Ｄに配設されている。
１３Ｅは逆止め弁を示し、給水分岐管３Ｂと第３バイパス管１５Ｆとの間の第１バイパス管１５Ｄに配設されている。
１７Ｄは流量調整弁としての絞り弁を示し、給水分岐管３Ａと第３バイパス管１５Ｆとの間の第２バイパス管１５Ｅに配設されている。
１７Ｆは流量調整弁としての絞り弁を示し、給水分岐管３Ｂと第３バイパス管１５Ｆとの間の第２バイパス管１５Ｅに配設されている。
【００７１】
Ｗは給水分岐管３Ａと第２バイパス管１５Ｅとの接続点、Ｘは給水分岐管３Ｂと第２バイパス管１５Ｅとの接続点を示す。
なお、電動ポンプ１２Ａの締め切り運転状態における吐出量と、第２バイパス管１５Ｅから接続点Ｗへの流入量とは、異なるように絞り弁１７Ｄで調整され、例えば流入量が少なくされている。
また、電動ポンプ１２Ｂの締め切り運転状態における吐出量と、第２バイパス管１５Ｅから接続点Ｘへの流入量とは、異なるように絞り弁１７Ｅで調整され、例えば流入量が多くされている。
しかし、両電動ポンプ１２Ａ，１２Ｂの吐出量の和と、第２バイパス管１５Ｅから両接続点Ｗ，Ｘへの流入量の和とは、同じである。
【００７２】
この第３実施形態における各部の動作は先の説明と同様になるが、締め切り運転状態における水の流れが異なるので、以下に説明する。
この第３実施形態においては、上述したように、接続点Ｗにおける第２バイパス管１５Ｅからの流入量よりも電動ポンプ１２Ａの吸い込み量が多く、接続点Ｘにおける第２バイパス管１５Ｅからの流入量よりも電動ポンプ１２Ｂの吸い込み量が少ないので、受水槽４および第２バイパス管１５Ｅから接続点Ｗに流入する水は電動ポンプ１２Ａに吸い込まれ、第２バイパス管１５Ｅから接続点Ｘに流入する水は電動ポンプ１２Ｂに吸い込まれるとともに、受水槽４へ還流する。
【００７３】
また、電動ポンプ１２Ｂが吸い込む水は電動ポンプ１２Ａを通過したものであるが、第２バイパス管１５Ｅから接続点Ｘに流入する水の一部は受水槽４へ還流するので、電動ポンプ１２Ａ、各バイパス管１５Ｄ，１５Ｅ，１５Ｆ、電動ポンプ１２Ｂを循環する水は少しずつ入れ代わる。
【００７４】
上述したように、この発明の第３実施形態によれば、電動ポンプ１２Ａ，１２Ｂよりも下流で、逆止め弁１３Ａ，１３Ｂよりも上流の給水分岐管３Ａ，３Ｂを第１バイパス管１５Ｄで連通させ、電動ポンプ１２Ａ，１２Ｂよりも上流の給水分岐管３Ａ，３Ｂを第２バイパス管１５Ｅで連通させるとともに、第１バイパス管１５Ｄと第２バイパス管１５Ｅとを第３バイパス管１５Ｆで連通させ、第２バイパス管１５Ｅに絞り弁１７Ｄ，１７Ｅを配設したので、電動ポンプ１２Ａ，１２Ｂの締め切り運転状態においても、受水槽４から電動ポンプ１２Ａに流入する水に熱を放熱することにより、電動ポンプ１２Ａの温度上昇を低く抑えることができる。
また、電動ポンプ１２Ａ、各バイパス管１５Ｄ，１５Ｅ，１５Ｆ、電動ポンプ１２Ｂを循環する水は少しずつ入れ代わるので、入れ代わる水による放熱作用により、電動ポンプ１２Ｂの温度上昇を低く抑えることができる。
【００７５】
したがって、電動ポンプ１２Ａ，１２Ｂの電動機巻線、軸受部およびメカニカルシールの温度上昇を低く抑えることができるので、電動ポンプ１２Ａ，１２Ｂの寿命を長くすることができる。
また、電動ポンプ１２Ａ，１２Ｂの電動機巻線、軸受部およびメカニカルシールの温度上昇を低く抑えるための各バイパス管１５Ｄ〜１５Ｆの長さが短くて済むので、所期の目的を安価な構成で達成することができる。
【００７６】
図４はこの発明の第４実施形態である給水装置の要部を示すブロック図であり、図示を省略した部分は、図６および図７と同様に構成されている。
この第４実施形態は、第３実施形態が２台の電動ポンプ１２Ａ，１２Ｂであるのに対し、３台の電動ポンプ１２Ａ〜１２Ｃである点が異なるのみである。
【００７７】
この第４実施形態における各部の動作は先の説明と同様になり、締め切り運転状態における水の流れは第３実施形態と同様になるので、省略するが、各実施形態と同様な効果を得ることができる。
【００７８】
図５はこの発明の第５実施形態である給水装置の要部を示すブロック図であり、図示を省略した部分は、図６および図７と同様に構成されている。
この第５実施形態は、第１実施形態と第３実施形態とを組み合わせたものである。
【００７９】
この第５実施形態における各部の動作は先の説明と同様になり、締め切り運転状態における水の流れは第１実施形態と第３実施形態とを組み合わせたものになるので、省略するが、各実施形態と同様な効果を得ることができる。
【００８０】
上記した第１および第２実施形態において、締め切り運転状態における電動ポンプ１２Ａ〜１２Ｃの吸い込み側にバイパス管１５Ａ〜１５Ｃで供給される流量と、その電動ポンプ１２Ａ〜１２Ｃがバイパス管１５Ａ〜１５Ｃへ吐出する流量とが電動ポンプ１２Ａ〜１２Ｃの特性によって異なる場合は、電動弁１６Ａ〜１６Ｃおよび絞り弁１７Ａ〜１７Ｃを省略しても同様な効果を得ることができる。
【００８１】
また、第３および第４実施形態において、締め切り運転状態における電動ポンプ１２Ａ〜１２Ｃの吸い込み側に各バイパス管１５Ｄ〜１５Ｆで供給される流量と、その電動ポンプ１２Ａ〜１２Ｃが第１バイパス管１５Ｄへ吐出する流量とを絞り弁１７Ｄ〜１７Ｅで異ならせているが、いずれかの絞り弁を省略して、各電動ポンプ１２Ａ〜１２Ｃの吸い込み量と第２バイパス管１５Ｅから各電動ポンプ１２Ａ〜１２Ｃの上流の給水配管３Ａ〜３Ｃへの流入量とを異ならせるようにしたり、各電動ポンプ１２Ａ〜１２Ｃの吸い込み量と第２バイパス管１５Ｅから各電動ポンプ１２Ａ〜１２Ｃの上流の給水配管３Ａ〜３Ｃへの流入量とを異ならせるように第２バイパス管１５Ｅを構成し、絞り弁１７Ａ〜１７Ｃを省略しても、同様な効果を得ることができる。
【００８２】
そして、図１は請求項１の一例を示したものであるが、電動ポンプは３台以上であってもよく、各電動ポンプよりも下流で、各逆止め弁よりも上流の各給水配管をバイパス管でその電動ポンプ以外の上流の給水配管に連通させる構成であれば、同様な効果を得ることができる。
【００８３】
また、図２は請求項２の一例を示したものであるが、電動ポンプは２台以上であればよく、電動ポンプよりも下流で、逆止め弁よりも上流の給水配管をバイパス管でその電動ポンプの上流の給水配管に連通させたその電動ポンプよりも上流の給水配管に、その電動ポンプ以外の電動ポンプよりも下流で、逆止め弁よりも上流の給水配管をバイパス管で少なくとも１つ接続し、その電動ポンプよりも上流の給水配管に接続されていない、各電動ポンプよりも下流で、各逆止め弁よりも上流の各給水配管をバイパス管でその電動ポンプ以外の上流の給水配管に連通させた構成であればよい。
【００８４】
さらに、受水槽４から給水する例で説明したが、図６に示すように、給水本管２から直接給水する構成であってもよい。
このように給水本管２から直接給水する場合、第３〜第５実施形態において、第２バイパス管１５Ｅを省略して第３バイパス管１５Ｆを給水本管２に連通させるとともに、第３バイパス管１５Ｆに絞り弁を配設しても、同様な効果を得ることができる。
【００８５】
また、第１実施形態と第３実施形態とを組み合わせることによって第５実施形態となるが、第１実施形態、第２実施形態および第３実施形態を適当に組み合わせてこの発明の給水装置とすることができることは言うまでもない。
【００８６】
さらに、推定末端圧一定制御で給水する例で説明したが、推定末端圧一定制御部を吐出圧一定制御部に変えることにより、吐出圧一定制御で給水する給水装置にも適用できることは言うまでもない。
また、上述したように各バイパス管１５Ａ〜１５Ｃに電動弁１６Ａ〜１６Ｃおよび絞り弁１７Ａ〜１７Ｃを設けた例で説明したが、電動弁１６Ａ〜１６Ｃおよび絞り弁１７Ａ〜１７Ｃを省いても同様な効果を得ることができるとともに、バイパス管１５Ａ〜１５Ｃによる還流路に汎用性を持たせることができる。
【００８７】
このように電動弁１６Ａ〜１６Ｃおよび絞り弁１７Ａ〜１７Ｃを省くと、図８に示すように、常時バイパス流量ｑ_B で還流することになり、定格揚程、定格流量では動作点Ｐ₅ のバイパス流量ｑ_B となるので、前述の条件などを考慮して可能な限りバイパス流量ｑ_B を少量にして動力損失を少なくする必要がある。
そして、各制御部の構成は一例を示したもので、同様に機能する他の構成であってもよいことは言うまでもない。
【００８８】
さらに、圧力検出器１８，２０などで流量検出手段を構成した例を示したが、フロースイッチ１９を流量検出手段として利用できることは言うまでもない。
また、第１揚程を、設定最大締め切り揚程ｈ_pomax として説明したが、最大締め切り揚程にしたり、この最大締め切り揚程と、設定最大締め切り揚程ｈ_pomax との間の揚程にしても、同様な効果を得ることができる。
そして、第２揚程を、設定最小締め切り揚程ｈ_pomin として説明したが、許容最小締め切り揚程ｈ_pminにしたり、許容最大締め切り揚程ｈ_pmaxと許容最小締め切り揚程ｈ_pminとの間の揚程にしても、同様な効果を得ることができる。
【００８９】
さらに、受水槽４から給水する給水装置の例で説明したが、図６に示すように、水道管に接続する給水装置にも適用でき、同様な効果を得ることができる。
また、時計およびカレンダを設け、凍結しない時期の夜中の１２時頃から翌朝の５時頃までのように水道を使用しない時間帯と、発停の少ない時間帯とを記憶させ、その時間帯は電動ポンプ１２Ａ〜１２Ｃを停止させる構成とすることも可能である。
【００９０】
そして、給水要求を流量検出手段の出力で判断する構成としたが、圧力検出器２０の圧力ｈ_i で判断する構成としてもよい。
さらに、タイマを参照することによって各時間の経過を確認し、各締め切り揚程制御へ移行する例で説明したが、電動ポンプ１２Ａ〜１２Ｃ、または水の温度を検出する各温度検出手段の出力に基づいて各締め切り揚程制御へ移行する構成とすることも可能である。
【００９１】
【発明の効果】
以上のように、この発明によれば、各電動ポンプよりも下流で、各逆止め弁よりも上流の各給水配管をバイパス管でその電動ポンプ以外の上流の給水配管に接続したり、または、電動ポンプよりも下流で、逆止め弁よりも上流の給水配管をバイパス管でその電動ポンプの上流の給水配管に連通させたその電動ポンプよりも上流の給水配管に、その電動ポンプ以外の電動ポンプよりも下流で、逆止め弁よりも上流の給水配管をバイパス管で少なくとも１つ連通させ、その電動ポンプよりも上流の給水配管に連通されていない、電動ポンプよりも下流で、逆止め弁よりも上流の給水配管をバイパス管でその電動ポンプ以外の上流の給水配管に連通させたり、または、電動ポンプよりも下流で、逆止め弁よりも上流の隣り合う給水配管を第１バイパス管で連通させ、電動ポンプよりも上流の隣り合う給水配管を第２バイパス管で連通させ、第１バイパス管と第２バイパス管とを第３バイパス管で連通させるとともに、給水配管と第３バイパス管との間に第１バイパス管に逆止め弁を配設し、各電動ポンプの吸い込み量と第２バイパス管から各電動ポンプの上流の給水配管への流入量とを異ならせるように第２バイパス管を構成したり、または、電動ポンプよりも下流で、逆止め弁よりも上流の隣り合う給水配管を第１バイパス管で連通させ、電動ポンプよりも上流の隣り合う給水配管を第２バイパス管で連通させるとともに、第１バイパス管と第２バイパス管とを第３バイパス管で連通させ、給水配管と第３バイパス管との間に第１バイパス管に逆止め弁を配設するとともに、第２バイパス管に絞り弁を配設したので、電動ポンプの締め切り運転状態においても、バイパス管以外から電動ポンプに流入する水に熱を放熱することにより、その電動ポンプの温度上昇を低く抑えることができる。
また、電動ポンプ、バイパス管を循環する水は少しずつ入れ代わるので、入れ代わる水による放熱作用により、その電動ポンプの温度上昇を低く抑えることができる。
【００９２】
したがって、電動ポンプの電動機巻線、軸受部およびメカニカルシールの温度上昇を低く抑えることができるので、電動ポンプの寿命を長くすることができる。
また、電動ポンプの電動機巻線、軸受部およびメカニカルシールの温度上昇を低く抑えるためのバイパス管の長さが短くて済むので、所期の目的を安価な構成で達成することができる。
【図面の簡単な説明】
【図１】この発明の第１実施形態である給水装置の要部を示すブロック図である。
【図２】この発明の第２実施形態である給水装置の要部を示すブロック図である。
【図３】この発明の第３実施形態である給水装置の要部を示すブロック図である。
【図４】この発明の第４実施形態である給水装置の要部を示すブロック図である。
【図５】この発明の第５実施形態である給水装置の要部を示すブロック図である。
【図６】本出願人が先に提案した給水装置の構成を示すブロック図である。
【図７】図６に示した制御部の一例の構成を示すブロック図である。
【図８】図６および図７に示した給水装置の動作を説明する揚程−流量特性図である。
【図９】図６および図７に示した給水装置における切換制御部のフローチャートである。
【符号の説明】
１ 給水配管
２ 給水本管
３Ａ〜３Ｃ 給水分岐管
４ 受水槽
１１ 逆止め弁
１２Ａ〜１２Ｃ 電動ポンプ
１３Ａ〜１３Ｅ 逆止め弁
１４Ａ〜１４Ｃ 締め切り弁
１５Ａ〜１５Ｃ バイパス管
１５Ｄ 第１バイパス管
１５Ｅ 第２バイパス管
１５Ｆ 第３バイパス管
１６Ａ〜１６Ｃ 電動弁
１７Ａ〜１７Ｅ 絞り弁
１８，２０ 圧力検出器
１９ フロースイッチ
２１ 制御部
２１ａ 推定末端圧力設定器
２１ｂ 減算器
２１ｃ 選択スイッチ
２１ｄ 比例積分制御器
２１ｅ 直線指令器
２１ｆ 一次遅れ要素
２１ｇ 二乗演算器
２１ｈ 定数乗算器
２１ｉ 第１締め切り揚程設定器
２１ｊ 第２締め切り揚程設定器
２１ｋ 選択スイッチ
２１ｌ 減算器
２１ｍ，２１ｏ 定数設定器
２１ｎ 加算器
２１ｐ〜２１ｒ 減算器
２１ｓ 比較器
２１ｔ 切換制御部
２２Ａ，２２Ｂ インバータ
ｈ_a 実揚程
ｈ_k 管端圧力
ｈ_c 固定揚程
ｈ_s 推定末端圧力
ｈ_i 圧力
ｎ^* 出力
ｎ^*2 出力
ａ 定数
ｈ_poi 出力
ｈ_pomax 設定最大締め切り揚程
ｈ_po 設定最小締め切り揚程
ｈ_omin 補償揚程
ｈ_suc 固定損失揚程
ｈ_su 圧力
ｈ_pos 出力
ｑ_min 最小流量
ｑ_B バイパス流量[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a water supply apparatus that supplies water with an electric pump.
[0002]
[Prior art]
In the conventional water supply device described above, a flow switch and a check valve are disposed in the water supply pipe downstream of the electric pump, and the electric pump is controlled via the inverter by the estimated terminal pressure constant control unit or the discharge pressure constant control unit. It is supposed to be configured.
[0003]
In this water supply apparatus, when the faucet disposed on the terminal side of the water supply pipe is opened to release water, the control unit is electrically driven so that the estimated terminal pressure is constant or the discharge pressure is constant based on the output of the flow switch or the like. Rotate the pump to pressurize and supply water.
When the faucet is closed, the flow switch stops detecting the flow of water and outputs a flow rate non-detection signal that is the first signal, so that the control unit is based on the flow rate non-detection signal from the flow switch. Stop the electric pump.
[0004]
Since the water pressure in the water supply pipe decreases from when the faucet is opened until the electric pump is operated, water of a predetermined pressure is discharged from the pressure tank to the water supply pipe by providing a pressure tank.
Then, a predetermined amount of water with a predetermined pressure is stored in the pressure tank after the faucet is closed until the electric pump stops.
Therefore, it is possible to supply water with a stable water pressure, and to reduce the number of electric pumps.
[0005]
However, since the electric pump starts and stops based on opening and closing of the faucet, a large noise is generated during operation of the electric pump due to frequent start and stop of the electric pump.
Moreover, since the service life of the mechanical seal and the bearing of the electric pump is shortened due to frequent start and stop of the electric pump, there is a disadvantage that the maintenance cost of the electric pump increases.
[0006]
Accordingly, the present applicant has previously proposed a water supply apparatus as Japanese Patent Application No. 8-272661 in order to eliminate the above-mentioned disadvantages.
[0007]
FIG. 6 is a block diagram showing the structure of the water supply apparatus previously proposed by the present applicant as Japanese Patent Application No. 8-272661.
The signal lines from the control unit to each motor-operated valve are not shown.
In FIG. 6, 1 is a water supply pipe, one end is connected to a water pipe (not shown), and a plurality of taps (not shown) are arranged at the other end.
The water supply pipe 1 is composed of a water supply main pipe 2 and two water supply branch pipes 3A and 3B inserted in parallel in the middle of the water supply main pipe 2.
[0008]
11 is a check valve disposed in the water supply main pipe 2 upstream of the water supply branch pipes 3A and 3B, 12A and 12B are electric pumps incorporating a motor, and the electric pump 12A is provided in the water supply branch pipe 3A. The electric pump 12B is disposed in the water supply branch pipe 3B.
13A is a check valve disposed in the water supply branch pipe 3A downstream of the electric pump 12A, 13B is a check valve disposed in the water supply branch pipe 3B downstream of the electric pump 12B, and 14A is a check valve 13A. A shut-off valve 14B is provided in the downstream water supply branch pipe 3A, and a shut-off valve 14B is provided in the feed water branch pipe 3B downstream of the check valve 13B.
[0009]
Reference numeral 15A denotes a bypass pipe that connects the feed water branch pipe 3A downstream of the electric pump 12A and upstream of the check valve 13A to the feed water branch pipe 3A upstream of the electric pump 12A.
Reference numeral 15B denotes a bypass pipe, which communicates the water supply branch pipe 3B downstream of the electric pump 12B and upstream of the check valve 13B with the water supply branch pipe 3B upstream of the electric pump 12B.
[0010]
Reference numeral 16A denotes a motor-operated valve disposed in the bypass pipe 15A, which is controlled by a switching control unit 21t described later, and opens and closes the flow path of the bypass pipe 15A.
Reference numeral 16B denotes an electric valve arranged in the bypass pipe 15B, which is controlled by the switching control unit 21t to open and close the flow path of the bypass pipe 15B.
Reference numeral 17A denotes a throttle valve provided in the bypass pipe 15A, and reference numeral 17B denotes a throttle valve provided in the bypass pipe 15B.
[0011]
18 is a pressure detector disposed in the water supply main pipe 2 upstream of the check valve 11, and 19 is a flow as a flow rate detecting means disposed in the water supply main pipe 2 downstream of the water supply branch pipes 3A and 3B. A switch 20 indicates a pressure detector disposed in the water supply main pipe 2 downstream of the check valves 13A and 13B.
Reference numeral 21 denotes a control unit, which controls the electric pumps 12A and 12B via the inverters 22A and 22B based on the outputs of the pressure detectors 18 and 20, and also controls the electric valves 16A and 16B.
[0012]
FIG. 7 is a block diagram showing a configuration of the control unit shown in FIG.
Note that the signal lines from the switching control unit to each motor-operated valve and each selection switch are not shown.
In FIG. 7, 21a indicates an estimated terminal pressure setter, and an actual lifting height h _a Pipe end pressure h _k Fixed lift h with _c And this fixed head h _c Pipe loss head kq ² Estimated end pressure h with _s Are output.
[0013]
21b denotes a subtracter, and an estimated terminal pressure h output from the estimated terminal pressure setter 21a. _s Pressure h detected by the pressure detector 20 _i Is the output of subtracting.
Reference numeral 21c denotes a selection switch for selecting an output of the subtractor 21b or an output of a subtractor 21l described later.
Reference numeral 21d denotes a proportional-integral controller that processes the output of the subtractor 21b via the selection switch 21c or the output of the subtractor 21l and outputs it to inverters 22A and 22B and a linear command device 21e described later.
[0014]
Reference numeral 21e denotes a linear command device, which has the same characteristics as the linear command device built in the inverters 22A and 22B, and receives the output of the proportional-integral controller 21d as an input.
Reference numeral 21f denotes a first-order lag element, which approximates the transmission delay of the electric pumps 12A and 12B up to the speed (the number of revolutions or the frequency) of the motor, and outputs the output of the linear command device 21e to n. ^* Is output as
21g denotes a square calculator, and the output n of the first-order lag element 21f ^* N as input ^{* 2} Is output.
[0015]
21h denotes a constant multiplier, and the output n of the square calculator 21g ^{* 2} Multiplied by a constant a which is a characteristic of the electric pumps 12A and 12B ^{* 2} H _poi Is output as
21i is the set maximum deadline h for the first lift _pomax The first deadline setting device 21j outputs a minimum deadline h set as the second lifting height 21j. _po The second deadline lift setting device 21k indicates a selection switch, and this selection switch 21k selects the output of the first deadline lift setting device 21i or the output of the second deadline lift setting device 21j.
[0016]
Reference numeral 21l denotes a subtracter, which is set by the first deadline lift setting device 21i. _pomax Or the minimum deadline lifting height h set by the second deadline lifting height setting device 21j _po To output h of the constant multiplier 21h _poi Is the output of subtracting.
21m indicates a constant setter and the compensation head h _omin Is set.
21n denotes an adder, and a fixed head h output from the estimated terminal pressure setter 21a. _c And the compensation head h output from the constant setter 21m _omin And the result of adding and is output.
[0017]
21o indicates a constant setter, the fixed loss lift h of the check valve 11 _suc Is set.
21p indicates a subtractor, and the pressure h detected by the pressure detector 18 _su To fixed loss lift h of constant setter 21o _suc Is the output of subtracting.
21q denotes a subtracter, and h is obtained by subtracting the output of the subtracter 21p from the output of the adder 21n. _pos Is output as
[0018]
Reference numeral 21r denotes a subtracter, which outputs a value obtained by subtracting the output of the constant multiplier 21h from the output of the subtractor 21q.
Reference numeral 21s denotes a comparator, which indicates whether the output of the subtractor 21r is greater than or equal to zero or negative, that is, the minimum flow rate q that the flow switch 19 can detect _min It is determined whether or not the following has occurred.
Reference numeral 21t denotes a switching control unit that controls the motor-operated valves 16A and 16B and the selection switches 21c and 21k based on the output of the comparator 21s as will be described later, and includes a ROM, a RAM, a CPU, a timer, and the like. Yes.
[0019]
The estimated terminal pressure constant control unit includes an estimated terminal pressure setter 21a, a subtractor 21b, and a proportional integral controller 21d.
The first deadline lift control unit includes a proportional integral controller 21d, a linear command device 21e, a first-order lag element 21f, a square calculator 21g, a constant multiplier 21h, a first deadline lift setter 21i, and a subtractor 21l. ing.
[0020]
Further, the second deadline lift control unit includes a proportional integral controller 21d, a linear command device 21e, a first-order lag element 21f, a square calculator 21g, a constant multiplier 21h, a second deadline lift setter 21j, and a subtractor 21l. ing.
The flow rate detecting means includes an estimated terminal pressure setting device 21a, a subtractor 21b, a proportional integration controller 21d, a linear command device 21e, a first-order lag element 21f, a square computing device 21g, a constant multiplier 21h, and constant setting devices 21m and 21o. , An adder 21n, subtractors 21p, 21q, and 21r, and a comparator 21s.
[0021]
FIG. 8 is a head-flow rate characteristic diagram for explaining the operation of the water supply apparatus shown in FIGS. 6 and 7.
This characteristic is obtained when the effective push lift is zero, that is, the suction push lift (pressure h in FIG. 7). _su ) To the fixed loss lift h of the check valve 11 _suc The unit head method shows the lift-flow rate characteristics of an electric pump with constant estimated terminal pressure control when the value obtained by subtracting 0 is zero.
[0022]
In FIG. 8, A is an estimated terminal pressure constant control curve, R is a loss curve obtained by summing the friction loss of the bypass pipe 15A or the bypass pipe 15B and the throttle loss of the throttle valve 17A or the throttle valve 17B, P ₁ Is the rated flow rate through q = 1.0, h = 1.0 on the estimated terminal pressure constant control curve A, the operating point of the rated head, P ₂ Is the minimum flow rate q on the estimated terminal pressure constant control curve A _min Operating point at P _Three Is the operating point in the first deadline lift control, P _Four Is the operating point in the second deadline lift control, P _Five Is the bypass flow rate q flowing through the bypass pipes 15A and 15B when the motor-operated valves 16A and 16B are opened and the first dead-end control is performed. _B The operating point is shown.
The operating point P _Three ~ P _Five Is located on the loss curve R.
[0023]
Here, each control will be described.
First, when the estimated terminal pressure constant control is reached, the operating point P on the estimated terminal pressure constant control curve A ₁ And operating point P ₂ Water will be supplied while moving between the two.
[0024]
When the first deadline lift control is performed, the operating point is the operating point P. _Three It becomes.
The maximum set deadline h _pomax Is smaller than the minimum lift in the estimated terminal pressure constant control, and the fixed lift h _c The flow rate of the bypass pipe 15A or the bypass pipe 15B is slightly smaller than the bypass flow rate q. _B Allowable maximum deadline for lifting (when the check valves 13A and 13B are closed and refluxed via the bypass pipes 15A and 15B, the temperature rise of the electric pumps 12A and 12B is made to be below the allowable value. Lifting height) h _pmax The maximum allowable deadline h is _pmax Is approximate.
This operating point P _Three Shaft power at the operating point pressure h _PB ≒ h _pomax From this relationship, it can be expressed as the following equation (1).
[0025]
[Expression 1]

[0026]
However, l ₂ : Operating point P _Three Shaft power (pu) = L ₂ / L _N (P.u.)
L ₂ : Operating point P _Three Shaft power (kW)
L _N : Rated shaft power (kW)
h _pomax : Maximum set deadline (pu) <(h _a + H _k ) (Pu)
h _a : Actual head (pu) = H _a / H _N (P.u.)
h _k : Pipe end pressure (pu) = H _K / H _N (P.u.)
H _a : Actual head (m)
H _k : Pipe end pressure (m)
H _N : Rated head (m) of electric pumps 12A and 12B
η _qB : Bypass flow q _B (P.u.) Electric pump efficiency (pu)
q _B : Bypass flow rate in the first deadline lift control (pu)
[0027]
Since the shaft power obtained by subtracting the bypass pipe head loss and the work given to water from the shaft power given by the expression (1) is consumed in the electric pumps 12A and 12B, the bypass flow q _B If it is too small, the temperature of water, impellers, packing, bearings, mechanical seals, electric motor coils, etc. in the electric pumps 12A and 12B will rise.
Then, the relationship between the shaft power and the bypass flow rate is obtained by an experimental value or a test value so that the temperature rise of each part falls within the specified value for each electric pump, and the relationship between the obtained shaft power and the bypass flow rate is satisfied. Maximum allowable deadline h _pmax The maximum deadline for setting h _pomax To decide.
[0028]
The allowable maximum deadline h thus obtained _pmax Operating point at or maximum set deadline h _pomax Operating point P at _Three Is the operating point that keeps the check valves 13A, 13B closed.
And the set maximum deadline h _pomax Can continuously operate the electric pumps 12A and 12B, but the allowable maximum deadline h _pmax Can operate the electric pumps 12A and 12B for a limited time.
[0029]
In the second deadline lift control, the set minimum deadline lift is h. _po It becomes.
This set minimum deadline lift h _po Is a value that satisfies the expression (2), and allows the mechanical seals of the electric pumps 12A and 12B to be lubricated, and the allowable minimum deadline h that minimizes the frictional resistance. _pmin Set the value as close as possible to.
[0030]
[Expression 2]

[0031]
However, h _pmax : Allowable maximum deadline (p.u.) <(H _a + H _k ) (Pu)
h _po : Set minimum deadline (p.u.)
h _pmin : Allowable minimum deadline (p.u.)
Allowable minimum deadline lifting height h _pmin Is a deadline that can lubricate the mechanical seals of the electric pumps 12A and 12B and minimize the frictional resistance.
In the second deadline lifting height control given by the expression (2), the electric pumps 12A and 12B are operated at a low speed, and the operation is quiet and energy saving.
[0032]
Furthermore, the small flow rate detection of the flow rate detection means will be described.
In FIG. 8, the small flow rate operation is (hq) _min Then, the deadline lift given by the electric pumps 12A and 12B at this time is expressed as the following expression (3) when the hq characteristic is approximated by a quadratic expression of the speed and flow rate of the electric pumps 12A and 12B. be able to.
[0033]
[Equation 3]

[0034]
Where a: constant of the electric pumps 12A and 12B
n: Speed (pu) of electric pumps 12A and 12B = N / N _N (P.u.)
N: Speed (rpm) of the electric pumps 12A and 12B
N _N : Rated speed (rpm) of electric pumps 12A and 12B
h _a : Actual head (pu)
h _k : Pipe end pressure (pu)
h _omin : Compensation head (pu)
h _su : Pump pushing head (pu) = H _su / H _N (P.u.)
H _su : Pump pushing head (inside of check valve 11) (m)
H _N : Rated head (m) of electric pumps 12A and 12B
h _suc : Non-return valve 11 fixed loss lift (pu) = H _suc / H _N (P.u.)
H _suc : Fixed loss lift of the check valve 11 (pu)
[0035]
(H) in this equation (3) _su -H _suc ) Is an effective push head, and as shown in FIG. 6, when the pressure detector 18 is provided on the water pipe side, the pressure h as a detection value _su And the actual measured fixed loss head h _suc It is obtained by the difference.
Therefore, the flow rate of the water supply main pipe 2 downstream of the check valves 13A and 13B is the minimum flow rate q. _min Can be detected.
[0036]
FIG. 9 is a flowchart of the switching control unit in the water supply apparatus shown in FIGS. 6 and 7.
In FIG. 9, ST1 to ST10 indicate steps.
[0037]
Next, control of the switching control unit and water supply will be described.
In the state where the faucet (not shown) is opened and water is supplied, the comparator 21s has a minimum flow rate q _min More second signals are output.
First, the switching control unit 21t determines that the output of the comparator 21s is the minimum flow rate q _min It is determined whether it is the following first signal (step ST1), and the output of the comparator 21s is the minimum flow rate q _min If the following signal is not the first, that is, the flow rate is the minimum flow rate q _min If it is the water supply state which is more second signals, the selector switches 21c and 21k are switched to the contact a side, and the motor operated valves 16A and 16B are closed (step ST2), and the process returns to step ST1.
[0038]
Thus, when the selection switches 21c and 21k are brought into the contact a side by the control of the switching control unit 21t, the pressure h of the pressure detector 20 is increased. _i Detected value, estimated terminal pressure setter 21a estimated terminal pressure h _s Is set to a set value, and the output of the proportional-integral controller 21d changes so that the difference between the two becomes zero, and the known terminal pressure constant control is performed.
Therefore, the operating point P on the estimated terminal pressure constant control curve A in FIG. ₁ And operating point P ₂ It is estimated terminal pressure constant control that moves between the two.
[0039]
And by closing all the faucets, the flow rate is reduced to the minimum flow rate q _min The flow rate from the comparator 21s becomes the minimum flow rate q when _min The following first signal is output.
When the first signal is output from the comparator 21s in this way, the switching control unit 21t confirms that the signal from the comparator 21s is the first signal (step ST1), and then sets a timer (step ST1). ST3).
Then, referring to the timer, it is determined whether a first predetermined time, for example, 60 seconds has elapsed (step ST4). If 60 seconds have not elapsed, it is determined whether the first signal from the comparator 21s is continuing. (Step ST5).
[0040]
If it is determined in step ST5 that the first signal from the comparator 21s is not continued, the process returns to step ST1, and if the first signal from the comparator 21s is continued, the process returns to step ST4.
If 60 seconds have elapsed in the determination of step ST4, the selector switch 21c is switched to the contact b side, the motorized valves 16A and 16B are opened, and a timer is set (step ST6).
[0041]
In this way, when the selection switch 21c is brought to the contact b side by the control of the switching control unit 21t, the output of the proportional-plus-integral controller 21d is detected, and the set maximum deadline h of the first deadline setter 21i. _pomax Is set to the first value, and the first dead-end control is performed so that the output of the proportional-plus-integral controller 21d changes so that the difference between them becomes zero. Therefore, the check valves 13A and 13B slowly adjust the pressure of the downstream water supply pipe 1 The water supply branch pipes 3A and 3B are closed while being maintained, and the water discharged from the electric pumps 12A and 12B returns to the upstream of the electric pumps 12A and 12B via the bypass pipes 15A and 15B.
[0042]
Then, the switching control unit 21t determines whether or not the first signal from the comparator 21s continues (step ST7). If the first signal from the comparator 21s does not continue, the process returns to step ST2 to compare the first signal. If the first signal from the device 21s continues, it is determined by referring to the timer whether a second predetermined time, for example, 30 minutes has elapsed (step ST8).
[0043]
If it is determined in step ST8 that 30 minutes have not elapsed, the process returns to step ST7, and if 30 minutes continues, the selection switch 21k is switched to the contact b side (step ST9), and the signal from the comparator 21s Waits for the signal to become the second signal (step ST10).
Thus, when the selection switches 21c and 21k are brought into the contact b side by the control of the switching control unit 21t, the output of the proportional-plus-integral controller 21d is detected, and the set minimum deadline h of the second deadline setter 21j. _po Is set as a set value, and the second deadline lift control is performed in which the output of the proportional-plus-integral controller 21d changes so that the difference between the two becomes zero. Therefore, water discharged from the electric pumps 12A and 12B is bypassed by the bypass pipes 15A and 15B. Circulates upstream of the electric pumps 12A and 12B.
[0044]
When the signal from the comparator 21s becomes the second signal (step ST10), the switching control unit 21t returns to step ST2.
[0045]
As described above, according to the water supply apparatus previously proposed by the present applicant, the electric pumps 12A and 12B rotate without stopping, that is, do not repeat starting and stopping, and even during water supply, from the low speed to the predetermined speed. Therefore, the noise at the time of rising to a predetermined number of revolutions can be reduced, so that quick water supply can be handled, and the electric pumps 12A and 12B can be prevented from being damaged by freezing.
Since the electric pumps 12A and 12B rotate without repeating the start and stop, the service life of the mechanical seals and bearings of the electric pumps 12A and 12B is prolonged, so that the maintenance cost of the electric pumps 12A and 12B can be reduced. it can.
[0046]
Further, in the first deadline lift control, the check valves 13A and 13B are softly closed to hold the pressure, so that the generation of noise due to the water hammer can be prevented, the pressure tank becomes unnecessary, or the pressure tank Therefore, the water supply device can be made compact.
Further, since the rotation speed of the electric pumps 12A and 12B is in a standby state for a long time by the second deadline lift control at a lower speed than the first deadline lift control, the electric pumps 12A and 12B are continuously operated. In addition, the running cost when water is not supplied can be reduced to a level comparable to the case where the electric pumps 12A and 12B are stopped, and the operation is quiet.
[0047]
Since the throttle valves 17A and 17B are provided in the bypass pipes 15A and 15B, the bypass flow rate q _B Can be adjusted, and versatility can be given to the reflux path by the bypass pipes 15A and 15B.
Further, when water is supplied with the estimated terminal pressure constant control, the bypass pipes 15A and 15B are closed to eliminate reflux, so that water can be supplied efficiently.
[0048]
[Problems to be solved by the invention]
In the water supply apparatus previously proposed by the applicant, the shaft power of the electric pumps 12A and 12B in the closing operation state is all consumed in the electric pumps 12A and 12B to increase the water temperature, and in the closing operation state. Since the total length connecting the discharge side and the water absorption side of the electric pumps 12A, 12B is short by the length of the bypass pipes 15A, 15B, the heat of the water is effectively dissipated and the motor windings and bearings of the electric pumps 12A, 12B In addition, there is a limit to keeping the temperature rise of the mechanical seal low, and there is a disadvantage that the life of the electric pumps 12A and 12B is shortened.
[0049]
The present invention has been made to solve the above-described disadvantages, and provides a water supply device that can extend the life of an electric pump by suppressing a temperature rise of a motor winding, a bearing portion, and a mechanical seal to a low level. is there.
[0050]
In the present invention, a check valve is provided in each water supply pipe downstream of the electric pump arranged in parallel, and each water supply pipe downstream of each electric pump and upstream of each check valve is provided with a bypass pipe. In the water supply apparatus that communicates with the water supply pipe upstream of the electric pump and supplies water by rotating the electric pump without stopping at the estimated terminal pressure constant control unit or the discharge pressure constant control unit, downstream of each electric pump, Each of the water supply pipes upstream of each check valve is communicated with each of the water supply pipes upstream of the electric pump through the bypass pipes.
[0051]
Alternatively, the water supply pipe upstream of the check pump is connected to the water supply pipe upstream of the electric pump by connecting the water supply pipe upstream of the check valve to the water supply pipe upstream of the electric pump. At least one water supply pipe downstream of the electric pump and upstream of the check valve is connected by a bypass pipe, and is not connected to the water supply pipe upstream of the electric pump and downstream of the electric pump. A water supply pipe upstream from the valve is connected to an upstream water supply pipe other than the electric pump by a bypass pipe.
[0052]
Alternatively, the adjacent water supply pipe downstream of the electric pump and upstream of the check valve is communicated with the first bypass pipe, and the adjacent water supply pipe upstream of the electric pump is communicated with the second bypass pipe, and the first The bypass pipe and the second bypass pipe are communicated with each other by the third bypass pipe, and a check valve is disposed in the first bypass pipe between the water supply pipe and the third bypass pipe, The 2nd bypass pipe is constituted so that the amount of inflow from the 2 bypass pipes to the water supply pipes upstream of each electric pump may be different.
[0053]
Alternatively, the adjacent water supply pipe downstream of the electric pump and upstream of the check valve is connected by the first bypass pipe, and the adjacent water supply pipe upstream of the electric pump is connected by the second bypass pipe, and the first The first bypass pipe and the second bypass pipe communicate with each other through the third bypass pipe, and a check valve is disposed in the first bypass pipe between the water supply pipe and the third bypass pipe, and the throttle valve is provided in the second bypass pipe. Is provided.
[0054]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing a main part of a water supply apparatus according to a first embodiment of the present invention, and the parts not shown are configured in the same manner as in FIGS.
In FIG. 1, 4 shows a water receiving tank and one end side of the water supply branch pipes 3A and 3B is connected.
[0055]
The bypass pipe 15A communicates the water supply branch pipe 3A downstream of the electric pump 12A and upstream of the check valve 13A with the water supply branch pipe 3B upstream of the electric pump 12B.
Further, the bypass pipe 15B communicates the water supply branch pipe 3B downstream of the electric pump 12B and upstream of the check valve 13B with the water supply branch pipe 3A upstream of the electric pump 12A.
S represents a connection point between the water supply branch pipe 3A and the bypass pipe 15B, and T represents a connection point between the water supply branch pipe 3B and the bypass pipe 15A.
[0056]
It should be noted that the flow rate of the bypass pipe 15A when the electric pump 12A is closed and the flow rate of the bypass pipe 15B when the electric pump 12B is closed are that of the electric pumps 12A and 12B and the throttle valves 17A and 17B as flow rate adjusting valves. Since the characteristics are different, for example, the suction amount of the electric pump 12A is larger than the inflow amount from the bypass pipe 15B at the connection point S, and the suction amount of the electric pump 12B is smaller than the inflow amount from the bypass pipe 15A at the connection point T. .
Since one end of the bypass pipes 15A and 15B is connected to the water receiving tank 4, the pressure h in the expression (3) _su As the pressure h of the pressure detector 20 _i Can be substituted.
[0057]
Although the operation of each part in the first embodiment is the same as that described above, the flow of water in the deadline operation state is different and will be described below.
In the first embodiment, as described above, the suction amount of the electric pump 12A is larger than the inflow amount from the bypass pipe 15B at the connection point S, and the electric pump is larger than the inflow amount from the bypass pipe 15A at the connection point T. Since the amount of suction of 12B is small, the water flowing into the connection point S from the water receiving tank 4 and the bypass pipe 15B is sucked into the electric pump 12A, and the water flowing into the connection point T from the bypass pipe 15A is sucked into the electric pump 12B. , Reflux to the water receiving tank 4.
[0058]
The water sucked by the electric pump 12B passes through the electric pump 12A, but a part of the water flowing into the connection point T from the bypass pipe 15A returns to the water receiving tank 4, so that the electric pump 12A and the bypass pipe 15A The water circulating through the electric pump 12B and the bypass pipe 15B is replaced little by little.
[0059]
As described above, according to the first embodiment of the present invention, the water supply branch pipes 3A and 3B downstream of the electric pumps 12A and 12B and upstream of the check valves 13A and 13B are connected by the bypass pipes 15A and 15B. Because the upstream water supply branch pipes 3A and 3B other than the electric pumps 12A and 12B communicate with each other, heat is radiated from the water receiving tank 4 to the water flowing into the electric pump 12A even when the electric pumps 12A and 12B are closed. Thus, the temperature rise of the electric pump 12A can be kept low.
Moreover, since the water circulating through the electric pump 12A, the bypass pipe 15A, the electric pump 12B, and the bypass pipe 15B is replaced little by little, the temperature rise of the electric pump 12B can be suppressed to be lower than the heat dissipation action of the replaced water.
[0060]
Therefore, since the temperature rises of the motor windings, bearings, and mechanical seals of the electric pumps 12A and 12B can be kept low, the life of the electric pumps 12A and 12B can be extended.
Further, since the lengths of the bypass pipes 15A and 15B for suppressing the temperature rise of the motor windings, bearings, and mechanical seals of the electric pumps 12A and 12B can be shortened, the intended purpose can be achieved with an inexpensive configuration. be able to.
[0061]
FIG. 2 is a block diagram showing a main part of a water supply apparatus according to a second embodiment of the present invention, and the parts not shown are configured in the same manner as in FIGS.
In FIG. 2, 3C shows the water supply branch pipe which comprises the water supply piping 1, is arrange | positioned in parallel with the water supply branch pipes 3A and 3B, and one end is connected to the water receiving tank 4 with the water supply branch pipes 3A and 3B.
12C is an electric pump disposed in the water supply branch pipe 3C, 13C is a check valve disposed in the water supply branch pipe 3C downstream of the electric pump 12C, and 14C is a water supply branch pipe 3C downstream of the check valve 12C. The cutoff valve arrange | positioned is shown.
[0062]
Reference numeral 15C denotes a bypass pipe, which communicates the water supply branch pipe 3C downstream of the electric pump 12C and upstream of the check valve 13C with the water supply branch pipe 3B upstream of the electric pump 12B.
Reference numeral 16C denotes an electric valve disposed in the bypass pipe 15C, which is controlled by the switching control unit 21t described above to open and close the flow path of the bypass pipe 15C.
Reference numeral 17C denotes a throttle valve as a flow rate adjusting valve disposed in the bypass pipe 15C.
[0063]
The bypass pipe 15A communicates the water supply branch pipe 3A downstream of the electric pump 12A and upstream of the check valve 13A with the water supply branch pipe 3A upstream of the electric pump 12A.
Further, the bypass pipe 15B communicates the water supply branch pipe 3B downstream of the electric pump 12B and upstream of the check valve 13B with the water supply branch pipe 3A upstream of the electric pump 12A.
U represents a connection point between the water supply branch pipe 3A and the bypass pipes 15A and 15B, and V represents a connection point between the water supply branch pipe 3B and the bypass pipe 15C.
[0064]
In addition, since the characteristics of the electric pumps 12B and 12C and the throttle valves 17B and 17C are different from the flow rate of the bypass pipe 15B in the closing operation state of the electric pump 12B and the flow rate of the bypass pipe 15C in the closing operation state of the electric pump 12C, The suction amount of the electric pump 12A is smaller than the inflow amount from the bypass pipes 15A and 15B at the connection point U. For example, the suction amount of the electric pump 12B is larger than the inflow amount from the bypass pipe 15C at the connection point V.
[0065]
Although the operation of each part in the second embodiment is the same as that described above, the flow of water in the deadline operation state is different and will be described below.
In the second embodiment, as described above, the suction amount of the electric pump 12A is smaller than the inflow amount from the bypass pipes 15A and 15B at the connection point U, and is smaller than the inflow amount from the bypass pipe 15C at the connection point V. Since the suction amount of the electric pump 12B is large, the water flowing into the connection point U from the bypass pipes 15A and 15B is sucked into the electric pump 12A and returned to the water receiving tank 4 and connected to the connection point V from the water receiving tank 4 and the bypass pipe 15C. The water flowing into the electric pump 12B is sucked into the electric pump 12B, and the electric pump 12C sucks the water in the water receiving tank 4.
[0066]
The water sucked by the electric pump 12A passes through the electric pumps 12A and 12B, but a part of the water flowing into the connection point U from the bypass pipes 15A and 15B returns to the water receiving tank 4, and therefore the electric pump 12A. The water circulating through the bypass pipe 15A is replaced little by little.
[0067]
As described above, according to the second embodiment of the present invention, the feed water branch pipes 3A, 3B are electrically driven by the bypass pipes 15A, 15B downstream of the electric pumps 12A, 12B and upstream of the check valves 13A, 13B. The water supply branch pipe 3C is communicated with the water supply branch pipe 3A upstream of the pump 12A, and the water supply branch pipe 3C downstream of the electric pump 12C and upstream of the check valve 13C is connected to the water supply branch pipe 3B upstream of the electric pump 12B by the bypass pipe 15C. Since the electric pumps 12A to 12C are closed, the heat of the electric pumps 12B and 12C can be kept low by dissipating heat from the water receiving tank 4 to the water flowing into the electric pumps 12B and 12C. Can do.
Further, since the water circulating through the electric pump 12A and the bypass pipe 15A is replaced little by little, the temperature rise of the electric pump 12A can be suppressed to a low level by the heat radiation effect of the replaced water.
[0068]
Therefore, since the temperature rise of the motor windings, the bearing portions, and the mechanical seals of the electric pumps 12A to 12C can be kept low, the life of the electric pumps 12A to 12C can be extended.
In addition, since the length of the bypass pipes 15A to 15C for suppressing the temperature rise of the motor windings, bearings, and mechanical seals of the electric pumps 12A to 12C can be short, the intended purpose can be achieved with an inexpensive configuration. be able to.
[0069]
FIG. 3 is a block diagram showing a main part of a water supply apparatus according to a third embodiment of the present invention, and the parts not shown are configured in the same manner as in FIGS.
In FIG. 3, 15D indicates a first bypass pipe, which is downstream of the electric pump 12A, upstream of the check valve 13A, upstream of the check pump 13A, downstream of the electric pump 12B, and upstream of the check valve 13B. The water supply branch pipe 3B is communicated. 15E shows a 2nd bypass pipe, and connects the water supply branch pipe 3A upstream from the electric pump 12A and the water supply branch pipe 3B upstream from the electric pump 12B.
15F shows a 3rd bypass pipe and makes 1st bypass pipe 15D and the 2nd bypass pipe 15E communicate.
[0070]
Reference numeral 13D denotes a check valve, which is disposed in the first bypass pipe 15D between the water supply branch pipe 3A and the third bypass pipe 15F.
Reference numeral 13E denotes a check valve, which is disposed in the first bypass pipe 15D between the water supply branch pipe 3B and the third bypass pipe 15F.
Reference numeral 17D denotes a throttle valve as a flow rate adjusting valve, which is disposed in the second bypass pipe 15E between the water supply branch pipe 3A and the third bypass pipe 15F.
Reference numeral 17F denotes a throttle valve as a flow rate adjusting valve, which is disposed in the second bypass pipe 15E between the feed water branch pipe 3B and the third bypass pipe 15F.
[0071]
W represents a connection point between the water supply branch pipe 3A and the second bypass pipe 15E, and X represents a connection point between the water supply branch pipe 3B and the second bypass pipe 15E.
Note that the discharge amount in the closing operation state of the electric pump 12A and the inflow amount from the second bypass pipe 15E to the connection point W are adjusted differently by the throttle valve 17D, for example, the inflow amount is reduced.
Further, the discharge amount in the closing operation state of the electric pump 12B and the inflow amount from the second bypass pipe 15E to the connection point X are adjusted differently by the throttle valve 17E, for example, the inflow amount is increased.
However, the sum of the discharge amounts of both the electric pumps 12A and 12B is the same as the sum of the inflow amounts from the second bypass pipe 15E to both connection points W and X.
[0072]
Although the operation of each part in the third embodiment is the same as that described above, the flow of water in the deadline operation state is different and will be described below.
In the third embodiment, as described above, the suction amount of the electric pump 12A is larger than the inflow amount from the second bypass pipe 15E at the connection point W, and the inflow amount from the second bypass pipe 15E at the connection point X. Therefore, the water flowing into the connection point W from the water receiving tank 4 and the second bypass pipe 15E is sucked into the electric pump 12A and the water flowing into the connection point X from the second bypass pipe 15E. Is sucked into the electric pump 12B and returned to the water receiving tank 4.
[0073]
Further, the water sucked by the electric pump 12B passes through the electric pump 12A, but part of the water flowing into the connection point X from the second bypass pipe 15E returns to the water receiving tank 4, so that the electric pump 12A, The water circulating through the bypass pipes 15D, 15E, 15F and the electric pump 12B is replaced little by little.
[0074]
As described above, according to the third embodiment of the present invention, the water supply branch pipes 3A and 3B downstream of the electric pumps 12A and 12B and upstream of the check valves 13A and 13B are communicated by the first bypass pipe 15D. The water supply branch pipes 3A and 3B upstream of the electric pumps 12A and 12B are communicated with each other by the second bypass pipe 15E, and the first bypass pipe 15D and the second bypass pipe 15E are communicated by the third bypass pipe 15F. Since the throttle valves 17D and 17E are disposed in the second bypass pipe 15E, even when the electric pumps 12A and 12B are in the shut-off operation state, the electric pump radiates heat to the water flowing into the electric pump 12A from the water receiving tank 4. The temperature rise of 12A can be kept low.
Further, the water circulating through the electric pump 12A, the bypass pipes 15D, 15E, 15F, and the electric pump 12B is replaced little by little. Therefore, the temperature rise of the electric pump 12B can be kept low by the heat radiation effect of the replaced water.
[0075]
Therefore, since the temperature rises of the motor windings, bearings, and mechanical seals of the electric pumps 12A and 12B can be kept low, the life of the electric pumps 12A and 12B can be extended.
Moreover, since the length of each bypass pipe 15D-15F for suppressing the temperature rise of the motor windings, bearings and mechanical seals of the electric pumps 12A and 12B can be shortened, the intended purpose can be achieved with an inexpensive configuration. can do.
[0076]
FIG. 4 is a block diagram showing a main part of a water supply apparatus according to a fourth embodiment of the present invention, and the parts not shown are configured in the same manner as in FIGS.
The fourth embodiment is different from the third embodiment in that the third embodiment includes two electric pumps 12A and 12B, but the three electric pumps 12A to 12C.
[0077]
The operation of each part in the fourth embodiment is the same as described above, and the flow of water in the deadline operation state is the same as in the third embodiment, so it is omitted, but the same effect as each embodiment is obtained. Can do.
[0078]
FIG. 5 is a block diagram showing a main part of a water supply apparatus according to a fifth embodiment of the present invention, and the parts not shown are configured in the same manner as in FIGS.
The fifth embodiment is a combination of the first embodiment and the third embodiment.
[0079]
The operation of each part in the fifth embodiment is the same as described above, and the water flow in the deadline operation state is a combination of the first embodiment and the third embodiment. The same effect as the form can be obtained.
[0080]
In the first and second embodiments described above, the flow rate supplied by the bypass pipes 15A to 15C to the suction side of the electric pumps 12A to 12C in the closing operation state, and the electric pumps 12A to 12C are discharged to the bypass pipes 15A to 15C. When the flow rate to be changed differs depending on the characteristics of the electric pumps 12A to 12C, the same effect can be obtained even if the electric valves 16A to 16C and the throttle valves 17A to 17C are omitted.
[0081]
Moreover, in 3rd and 4th embodiment, the flow volume supplied by each bypass pipe 15D-15F to the suction side of electric pump 12A-12C in a closing operation state, and the electric pumps 12A-12C to 1st bypass pipe 15D Although the flow rate to be discharged is made different by the throttle valves 17D to 17E, any one of the throttle valves is omitted, and the suction amount of each of the electric pumps 12A to 12C and the electric pumps 12A to 12C from the second bypass pipe 15E. The amount of inflow into the upstream water supply pipes 3A to 3C is made different, or the suction amount of each electric pump 12A to 12C and the second bypass pipe 15E to the water supply pipes 3A to 3C upstream of each electric pump 12A to 12C Even if the second bypass pipe 15E is configured so as to be different from the inflow amount, and the throttle valves 17A to 17C are omitted, the same effect can be obtained. It can be.
[0082]
FIG. 1 shows an example of claim 1, but there may be three or more electric pumps, and each water supply pipe downstream from each electric pump and upstream from each check valve is provided. A similar effect can be obtained if the bypass pipe communicates with an upstream water supply pipe other than the electric pump.
[0083]
FIG. 2 shows an example of claim 2. However, the number of electric pumps may be two or more, and the water supply pipe downstream of the electric pump and upstream of the check valve is connected by a bypass pipe. At least one water supply pipe downstream of the electric pump other than the electric pump and upstream of the check valve is connected to the water supply pipe upstream of the electric pump connected to the water supply pipe upstream of the electric pump by a bypass pipe. Connected and not connected to the water supply piping upstream of the electric pump, downstream of each electric pump, and upstream of each check valve, each of the water supply piping upstream of the non-electric pump with a bypass pipe Any configuration may be used as long as it is communicated with.
[0084]
Furthermore, although the example of supplying water from the water receiving tank 4 has been described, a configuration in which water is supplied directly from the water supply main pipe 2 as shown in FIG.
When water is directly supplied from the water supply main pipe 2 in this way, in the third to fifth embodiments, the second bypass pipe 15E is omitted and the third bypass pipe 15F is connected to the water supply main pipe 2, and the third bypass pipe is used. Even if a throttle valve is provided at 15F, the same effect can be obtained.
[0085]
Moreover, although it becomes 5th Embodiment by combining 1st Embodiment and 3rd Embodiment, it is set as the water supply apparatus of this invention combining 1st Embodiment, 2nd Embodiment, and 3rd Embodiment suitably. It goes without saying that it can be done.
[0086]
Furthermore, although the example in which water is supplied with the estimated terminal pressure constant control has been described, it goes without saying that it can also be applied to a water supply apparatus that supplies water with the constant discharge pressure control by changing the estimated terminal pressure constant control unit to the discharge pressure constant control unit.
Further, as described above, the example in which the bypass valves 15A to 15C are provided with the motorized valves 16A to 16C and the throttle valves 17A to 17C has been described, but the same applies even if the motorized valves 16A to 16C and the throttle valves 17A to 17C are omitted. An effect can be acquired and versatility can be given to the reflux path by bypass pipe 15A-15C.
[0087]
When the motor-operated valves 16A to 16C and the throttle valves 17A to 17C are omitted in this way, as shown in FIG. _B At the rated head and flow rate, the operating point P _Five Bypass flow q _B Therefore, the bypass flow rate q is as much as possible in consideration of the above-mentioned conditions. _B It is necessary to reduce the power loss by making the amount small.
And the structure of each control part showed an example, and it cannot be overemphasized that the other structure which functions similarly may be sufficient.
[0088]
Furthermore, although the example in which the flow rate detection means is configured by the pressure detectors 18 and 20 has been shown, it goes without saying that the flow switch 19 can be used as the flow rate detection means.
In addition, the first lift is set to the maximum set deadline h _pomax As explained above, it can be the maximum deadline, or this maximum deadline and the set maximum deadline h _pomax The same effect can be obtained even if the head is between the two.
Then, the second lifting height is set to the minimum set lifting height h. _pomin As described above, the minimum allowable deadline h _pmin Or the allowable maximum deadline h _pmax And allowable minimum deadline h _pmin The same effect can be obtained even if the head is between the two.
[0089]
Furthermore, although demonstrated in the example of the water supply apparatus which supplies water from the water receiving tank 4, as shown in FIG. 6, it can apply also to the water supply apparatus connected to a water pipe, and can acquire the same effect.
In addition, a clock and calendar are provided, and the time zone when the water supply is not used and the time zone when there are few starts and stops, such as from around 12:00 in the middle of the night when it is not frozen to around 5 o'clock the next morning, are memorized. The electric pumps 12A to 12C may be configured to stop.
[0090]
And although it was set as the structure which judges a water supply request | requirement by the output of a flow volume detection means, the pressure h of the pressure detector 20 is used. _i It is good also as a structure judged by.
Furthermore, although the example which confirms progress of each time by referring to a timer and transfers to each deadline lift control was demonstrated, based on the output of each temperature detection means which detects the temperature of electric pumps 12A-12C or water. It is also possible to adopt a configuration for shifting to each deadline lift control.
[0091]
【The invention's effect】
As described above, according to the present invention, downstream of each electric pump, each water supply pipe upstream of each check valve is connected to an upstream water supply pipe other than the electric pump with a bypass pipe, or An electric pump other than the electric pump is connected to the water supply pipe upstream of the electric pump downstream of the electric pump and connected to the water supply pipe upstream of the electric pump by a bypass pipe. At least one water supply pipe upstream of the check valve is communicated with the bypass pipe downstream of the electric pump, and is not communicated with the water supply pipe upstream of the electric pump. In addition, the upstream water supply pipe is connected to an upstream water supply pipe other than the electric pump by a bypass pipe, or the adjacent water supply pipe downstream of the electric pump and upstream of the check valve is connected to the first bypass pipe. The pipe is connected, the adjacent water supply pipe upstream of the electric pump is connected with the second bypass pipe, the first bypass pipe and the second bypass pipe are connected with the third bypass pipe, and the water supply pipe and the third bypass are connected. A check valve is disposed in the first bypass pipe between the pipe and the second intake pipe so that the suction amount of each electric pump is different from the inflow amount from the second bypass pipe to the water supply pipe upstream of each electric pump. Configure a bypass pipe, or connect an adjacent water supply pipe downstream of the electric pump and upstream of the check valve with the first bypass pipe, and connect the adjacent water supply pipe upstream of the electric pump to the second bypass. The first bypass pipe and the second bypass pipe are communicated by the third bypass pipe, and a check valve is disposed in the first bypass pipe between the water supply pipe and the third bypass pipe. Second Viper Having provided a throttle valve in the tube, even in the deadline operating state of the electric pump, by radiating heat to the water flowing from outside the bypass pipe to the electric pump, it is possible to suppress the temperature rise of the electric pump lowered.
Moreover, since the water circulating through the electric pump and the bypass pipe is replaced little by little, the temperature rise of the electric pump can be suppressed low by the heat radiation effect of the replaced water.
[0092]
Therefore, the temperature rise of the electric motor winding, the bearing portion, and the mechanical seal of the electric pump can be suppressed low, and the life of the electric pump can be extended.
Moreover, since the length of the bypass pipe for suppressing the temperature rise of the electric motor winding, the bearing portion, and the mechanical seal of the electric pump can be shortened, the intended object can be achieved with an inexpensive configuration.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a main part of a water supply apparatus according to a first embodiment of the present invention.
FIG. 2 is a block diagram showing a main part of a water supply apparatus according to a second embodiment of the present invention.
FIG. 3 is a block diagram showing a main part of a water supply apparatus according to a third embodiment of the present invention.
FIG. 4 is a block diagram showing a main part of a water supply apparatus according to a fourth embodiment of the present invention.
FIG. 5 is a block diagram showing a main part of a water supply apparatus according to a fifth embodiment of the present invention.
FIG. 6 is a block diagram showing a configuration of a water supply apparatus previously proposed by the present applicant.
7 is a block diagram showing a configuration of an example of a control unit shown in FIG. 6. FIG.
8 is a head-flow rate characteristic diagram for explaining the operation of the water supply apparatus shown in FIGS. 6 and 7. FIG.
9 is a flowchart of a switching control unit in the water supply apparatus shown in FIGS. 6 and 7. FIG.
[Explanation of symbols]
1 Water supply piping
2 Water supply main
3A-3C Water supply branch pipe
4 water tank
11 Check valve
12A-12C Electric pump
13A-13E Check valve
14A-14C cutoff valve
15A-15C Bypass pipe
15D first bypass pipe
15E second bypass pipe
15F 3rd bypass pipe
16A-16C Motorized valve
17A-17E Throttle valve
18,20 Pressure detector
19 Flow switch
21 Control unit
21a Estimated terminal pressure setter
21b Subtractor
21c Selection switch
21d proportional integral controller
21e Linear command device
21f First order lag element
21g square calculator
21h Constant multiplier
21i First deadline lift setting device
21j Second deadline lift setting device
21k selection switch
21l subtractor
21m, 21o constant setting device
21n adder
21p-21r subtractor
21s comparator
21t switching control unit
22A, 22B inverter
h _a Actual head
h _k Pipe end pressure
h _c Fixed lift
h _s Estimated end pressure
h _i pressure
n ^* output
n ^{* 2} output
a constant
h _poi output
h _pomax Maximum set deadline
h _po Minimum set deadline
h _omin Compensation head
h _suc Fixed loss head
h _su pressure
h _pos output
q _min Minimum flow rate
q _B Bypass flow rate

Claims (4)

A check valve is provided in each water supply pipe downstream of the electric pump arranged in parallel, and each water supply pipe downstream of each electric pump and upstream of each check valve is connected by a bypass pipe. In the water supply apparatus that communicates with the water supply pipe 3 upstream of the electric pump and supplies water by rotating the electric pump without stopping at the estimated terminal pressure constant control unit or the discharge pressure constant control unit.
Downstream from each electric pump, the water supply pipes upstream from the check valves are connected to the water supply pipes other than the electric pump through the bypass pipes.
Each of the bypass pipes is provided with a throttle valve as a flow rate adjusting valve having different characteristics, and each electric pump characteristic is different,
The suction amount of the electric pump is larger than the inflow amount from the bypass pipe at the connection point between the bypass pipe and the water supply pipe, and the inflow amount from the other bypass pipe at the connection point between the other bypass pipe and the other water supply pipe. A water supply apparatus characterized in that the amount of suction of another electric pump is reduced . A check valve is provided in each water supply pipe downstream of the electric pump arranged in parallel, and each water supply pipe downstream of each electric pump and upstream of each check valve is connected by a bypass pipe. In the water supply device that communicates with the water supply pipe upstream of the electric pump and supplies water by rotating without stopping each electric pump in the estimated terminal pressure constant control unit or the discharge pressure constant control unit,
The water supply pipe upstream of the electric pump downstream of the electric pump and connected to the water supply pipe upstream of the electric pump by the bypass pipe is connected to the water supply pipe upstream of the check valve. At least one of the water supply pipes downstream of the electric pump other than the electric pump and upstream of the check valve is communicated with the bypass pipe, and is not communicated with the water supply pipe upstream of the electric pump. , Downstream of the electric pump, and upstream of the check valve, the water supply pipe is connected to the water supply pipe upstream of the bypass pump other than the electric pump,
Each of the bypass pipes is provided with a throttle valve as a flow rate adjusting valve having different characteristics, and each electric pump characteristic is different,
The amount of suction of one electric pump is larger than the amount of inflow from the bypass pipe at the connection point of the bypass pipe and the water supply pipe, and the amount of inflow from the other bypass pipe at the connection point of the other bypass pipe and the other water supply pipe The amount of suction of other electric pumps is less than
A water supply device characterized by that.   A check valve is provided in each water supply pipe downstream of the electric pump arranged in parallel, and each water supply pipe downstream of each electric pump and upstream of each check valve is connected by a bypass pipe. In the water supply apparatus that communicates with the water supply pipe upstream of the electric pump and rotates the electric pump without stopping by the estimated terminal pressure constant control unit or the discharge pressure constant control unit, in the downstream of the electric pump, The adjacent water supply pipe upstream of the check valve is communicated with a first bypass pipe, the adjacent water supply pipe upstream of the electric pump is communicated with a second bypass pipe, and the first bypass pipe and the The second bypass pipe communicates with the third bypass pipe, and a check valve is disposed in the first bypass pipe between the water supply pipe and the third bypass pipe, and the suction amount of each electric pump Wherein the second bypass pipe and constituting said second bypass pipe so as to vary the inflow into the water supply pipe upstream of the electric pump, the water supply device, characterized in that. A check valve is provided in each water supply pipe downstream of the electric pump arranged in parallel, and each water supply pipe downstream of each electric pump and upstream of each check valve is connected by a bypass pipe. In the water supply device that communicates with the water supply pipe upstream of the electric pump and supplies water by rotating without stopping each electric pump in the estimated terminal pressure constant control unit or the discharge pressure constant control unit,
The adjacent water supply pipe that is downstream of the electric pump and upstream of the check valve is connected by a first bypass pipe, and the adjacent water supply pipe that is upstream of the electric pump is connected by a second bypass pipe. In addition, the first bypass pipe and the second bypass pipe are communicated with each other by a third bypass pipe, and a check valve is disposed in the first bypass pipe between the water supply pipe and the third bypass pipe. A throttle valve is disposed in the second bypass pipe,
Adjusting the throttle valve so that the discharge amount in the closing operation state of the one electric pump is different from the inflow amount from the second bypass pipe to the connection point of the water supply pipe,
The water supply device according to claim 1, wherein the throttle valve is adjusted such that a discharge amount in a closing operation state of the other electric pump is different from an inflow amount from the second bypass pipe to a connection point of the water supply pipe .

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