JP3977607B2 - Waste heat recovery control device - Google Patents

Description

【００２５】
即ち、「給湯負荷」は、その時点の季節及び時刻における次回の給湯予想量であるから、例えば、７月Ｘ日、１８：００にＣＧＳ運転を開始する場合、給湯負荷は６０００ｋｃａｌで計算し、また、２月Ｙ日、５：００にＣＧＳ運転を開始する場合、給湯負荷は２０００ｋｃａｌで計算する。
【００２６】
また、「積算出力」は、制御部１２４に内蔵されている給湯積算出力カウンタ１２５を用いて求められる給湯及び注湯に使用された出力の合計である。即ち、給湯需要があると思われる時間帯で、バックアップと蓄熱利用を含めた全ての出力を求め、そのデータをエンジン運転時間にフィードバックする。
【００２７】
また、貯湯タンク３４のタンク蓄熱量の計算は、例えば、タンク容量を２００リットルとし、図５に示すように、貯湯タンク３４の各ゾーン１〜７は同容量であり、１ゾーン当たりの温水量は約２８．６リットルとなる。ここで、水温を冬期で５℃、春秋期で１５℃、夏期で２５℃と定義すると、各ゾーンの熱量Ｑ（ｋｃａｌ）は、
【００２８】
Ｑ＝２８．６×｛（上側検出温度＋下側検出温度）／２−水温｝・・・（２）
となり、タンク蓄熱量Ｑｍは全ゾーン１〜７の合計である。但し、一つの条件として｛（上側検出温度＋下側検出温度）／２−水温｝＜１０℃の場合には、そのゾーンは零とする。例えば、冬期、温度センサ６４１の検出温度が７５℃、温度センサ６４３の検出温度が７０℃のとき、ゾーン１の熱量Ｑ₁ は、
【００２９】
Ｑ₁ ＝２８．６×｛（７５＋７０）／２−５｝＝１９３０．５（ｋｃａｌ）・・・（３）
となる。なお、温度センサ６４１〜６５０の中、温度センサ６４２、６４９は蓄熱量Ｑｍの計算には使用しない。
【００３０】
そして、ステップＳ５で前記要求蓄熱量が１０００ｋｃａｌ以上であると判定されたとき、又はステップＳ３で暖房命令が発せられているとき、ステップＳ６に移行し、貯湯タンク３４の最下部側の温度センサ６５０の検出温度が所定温度、例えば、４０℃以上か否かを判定し、所定温度以下の場合、ステップＳ７に移行する。ステップＳ７では、前回のエンジン２の停止から所定時間、例えば、６０分以上経過したか否かが判定され、所定時間以下の場合には、エンジン保護のためエンジン２の起動を禁止する。即ち、貯湯タンク３４の最下部側の湯温が低温であることを確認し、エンジン２のオーバーヒートを防止している。そして、所定時間が経過している場合には、ステップＳ８に移行し、エンジン２の起動を行うとともに、暖機運転を行う。この暖機運転では、三方弁３０を切り換えてバイパス路２８を介して排熱回収路６を狭小化し、熱媒温度の急激な立上りを行う。
【００３１】
そして、この暖機運転の後、ステップＳ９に移行し、エンジン２の入口側の熱媒４の温度が所定温度、例えば、６５℃になるように制御する。この一定温度制御は、温度センサ８、１０の検出温度を監視しながら、直流モータ１７の回転数を増減させ、循環ポンプ１６で圧送される熱媒４の流量を加減することにより行われる。
【００３２】
次に、図６は、図４のステップＳ１の三方弁１４、３０、４２、４４等の弁初期位置設定のサブルーチンを示している。即ち、このサブルーチンがスタートすると、ステップＳ１０１で、三方弁４２はＤ−Ａ方向、三方弁４４はＤ−Ｃ（閉止）方向、三方弁３０はＣ−Ａ方向、三方弁１４はＣ−Ａ方向に切り換えられる。この結果、常時起動プログラムの実行が準備される。
【００３３】
次に、図７は、図４のメインルーチンのステップＳ２のサブルーチンであるエンジン異常停止制御を示している。即ち、このサブルーチンがスタートすると、ステップＳ２０１では、エンジン２の運転状態が「運転」であるか否かが判定され、運転状態にあるときはステップＳ２０２に移行し、所定時間として例えば、１０秒経過の後、ステップＳ２０３に移行し、ガス弁が閉（ＯＦＦ）であるか否かが判定され、閉でない場合にはステップＳ２０１に戻り、閉止している場合にはステップＳ２０４に移行し、エンジン停止を行った後、ステップＳ２０５に移行し、表示器１２６にエンジン異常停止を行った旨の表示としてアラーム表示を行う。
【００３４】
また、ステップＳ２０１で、エンジン２が運転状態でない場合には、ステップＳ２０６に移行し、所定時間として例えば、１０秒経過の後、ステップＳ２０７に移行し、ガス弁が開（ＯＮ）しているか否かが判定され、開でない場合にはステップＳ２０１に戻り、開の場合にはステップＳ２０８に移行し、エンジン停止を行った後、ステップＳ２０９に移行し、表示器１２６に「エンジン停止せず」とのアラーム表示を行う。
【００３５】
次に、図８は、図４のメインルーチンのステップＳ２のサブルーチンであるエンジン運転許可制御を示している。即ち、このサブルーチンがスタートすると、ステップＳ２１１では、エンジン運転が許可時間であるか否かが判定され、運転許可時間にある場合にはステップＳ２１２に移行し、エンジン運転許可指示として「許可」を出力し、また、エンジン運転許可時間でない場合にはステップＳ２１３に移行し、エンジン運転許可を禁止する指示として「禁止」を出力する。
【００３６】
次に、図９は、図４のメインルーチンのステップＳ２のサブルーチンであるエンジン停止制御を示している。即ち、このサブルーチンがスタートすると、ステップＳ２１５では、エンジン２の電源をＯＦＦにした後、ステップＳ２１６に移行し、弁初期位置制御（図６）を実行した後、ステップＳ２１７に移行し、エンジン２の運転状態を停止状態にする。
【００３７】
次に、図１０は、図４のメインルーチンのステップＳ２のサブルーチンであるエンジン強制停止制御を示している。即ち、このサブルーチンがスタートすると、ステップＳ２２１では、強制停止入力手段として例えば、Ｅｓｃキーが押されたか否かが判定され、このＥｓｃキーが押されたとき、ステップＳ２２２に移行し、エンジン停止制御（図９）を実行し、制御を終了する。
【００３８】
次に、図１１は、図４のメインルーチンのステップＳ２のサブルーチンである暖房運転命令制御を示している。即ち、このサブルーチンがスタートすると、ステップＳ２２５では、暖房装置側の暖房命令手段として端末スイッチがＯＮ又は双方向通信の暖房命令がＯＮしたか否かが判定され、暖房命令が指示されたとき、ステップＳ２２６に移行し、暖房命令を「ＯＮ」とし、制御手段であるバックアップインテリ基板のＥコン端子を「ＯＮ」とする。また、ステップＳ２２７では、暖房装置側の暖房命令手段として端末スイッチのＯＦＦと、双方向通信の暖房命令のＯＦＦとが成立しているか否かが判定され、暖房停止命令が指示されたとき、ステップＳ２２８に移行し、暖房命令を「ＯＦＦ」とし、制御手段であるバックアップインテリ基板のＥコン端子を「ＯＦＦ」とする。
【００３９】
次に、図１２は、図４のメインルーチンのステップＳ２のサブルーチンである給湯積算出力カウンタ１２５の制御を示している。即ち、このサブルーチンがスタートすると、ステップＳ２３１では、エンジン運転が「許可」であるか否かが判定され、許可の場合にはステップＳ２３２に移行し、カウンタリセットを行う。即ち、給湯積算出力カウンタ１２５に格納されている熱量Ｑｃを０ｋｃａｌとした後、ステップＳ２３３に移行し、水温を決定する。即ち、冬期では５℃、春秋期では１５℃、夏期では２５℃を設定した後、ステップＳ２３４に移行し、混合温サーミスタである温度センサ８２の湯温測定を行う。
【００４０】
そして、ステップＳ２３５では、給湯量を検出する流量センサ７８が所定流量として例えば、１リットルカウントしたか否かを判定し、１リットルカウントを行った場合、ステップＳ２３６に移行する。ステップＳ２３６では、１リットル当たりの熱量計算として給湯積算出力熱量Ｑｃを演算する。即ち、この給湯積算出力熱量Ｑｃ（ｋｃａｌ）は、
Ｑｃ＝（湯温−水温）×１（ｋｃａｌ） ・・・（４）
で算出される。
【００４１】
そして、ステップＳ２３７に移行し、エンジン運転許可が「禁止」されているか否かが判定され、エンジン運転が禁止されている場合にはステップＳ２３１に復帰し、エンジン運転が禁止されていない場合にはステップＳ２３４に移行し、ステップＳ２３４〜ステップＳ２３６の処理を実行する。
【００４２】
次に、図１３は、図４のメインルーチンのステップＳ２のサブルーチンである弁異常チェック制御を示している。即ち、このサブルーチンがスタートすると、ステップＳ２４１では、弁出力と切換状態を表すリミットが一致しているか否かが判定され、一致していない場合にはステップＳ２４２で所定時間として例えば、３０秒経過の後、ステップＳ２４３に移行し、表示器１２６に三方弁１４、３０、４２、４４等が異常である旨をアラームによって告知する。また、ステップＳ２４１で弁出力とリミットが一致している場合には、ステップＳ２４４に移行し、正常である旨出力し、表示器１２６にそれを表示する。
【００４３】
次に、図１４は、図４のメインルーチンのステップＳ２のサブルーチンである温度センサ異常チェック制御を示している。即ち、このサブルーチンがスタートすると、ステップＳ２５１では、接続線等に断線又は短絡の異常が生じているか否かが判定され、異常が生じている場合にはステップＳ２５２に移行し、表示器１２６に温度センサ８、１０等が異常である旨をアラームによって告知する。また、ステップＳ２５１で異常が生じていない場合には、ステップＳ２５３に移行し、正常である旨出力し、表示器１２６にそれを表示する。
【００４４】
次に、図１５は、図４に示すフローチャートのステップＳ８のサブルーチンであるエンジン起動及び暖機運転の制御を示している。
【００４５】
ステップＳ８０１では、温水３２の自然対流を防止するため、三方弁４２をＤ−Ａ方向、三方弁４４をＤ−Ｃ（閉止）方向、暖機回路を構成するため、三方弁３０をＣ−Ａ方向、三方弁１４をＣ−Ａ方向に切り換えるとともに、循環ポンプ１６を中回転に設定した後、ステップＳ８０２に移行し、温度センサ１０の検出温度が所定温度、例えば、５５℃以下であるか否かを判定し、この５５℃を超えている場合、ステップＳ８０３に移行し、プリチェックの開始から所定時間として例えば、２０分が経過したか否かを判定する。５５℃を超えて２０分が経過している場合には何らかの異常が発生していることが予想されるので、ステップＳ８０４に移行し、表示器１２６にアラームを発生させ、「異常停止」を告知する。このとき、エンジン２の停止モードに移行することになる。
【００４６】
ステップＳ８０２で検出温度が所定温度以下の場合、ステップＳ８０５に移行してエンジン２の電源をＯＮとし、ステップＳ８０６に移行してエンジン起動接点を所定時間、例えば、５秒間だけＯＮ状態とし、ステップＳ８０７に移行してエンジン起動接点をＯＦＦにした後、所定時間、例えば、３秒間待機し、ステップＳ８０８に移行する。ステップＳ８０８では、ガス弁がＯＮ状態か否かを判定し、ガス弁がＯＮ状態でない場合、ステップＳ８０９に移行し、その起動が所定回数、例えば、５回目か否かを判定する。所定回数以下の場合には、ステップＳ８１０に移行し、所定回数に移行する所定時間、例えば、５秒間待機してステップＳ８０６に戻る。また、ステップＳ８０９でエンジン起動が所定回数に到達している場合、ステップＳ８１１に移行してエンジン停止とし、ステップＳ８１２で表示器１２６にアラームを発生させるとともに、エンジン起動失敗を告知させる。この告知によって利用者は、異常を知ることができる。
【００４７】
ステップＳ８０８でガス弁がＯＮに移行したと判定されたとき、ステップＳ８１３に移行してエンジン２は運転状態となり、ステップＳ８１４に移行する。ステップＳ８１４では温度センサ１０の検出温度が所定温度、例えば、６０℃を超えているか否かを判定し、６０℃を超えていない場合、ステップＳ８１５に移行し、所定時間の経過、例えば、２０分が経過したか否かを判定し、所定時間が経過するまで、検出温度の推移を監視する。２０分が経過したにも拘わらず、検出温度が６０℃を超えない場合には、ステップＳ８１６に移行してエンジン停止を行った後、ステップＳ８１７に移行し、表示器１２６にアラームを発生させるとともに、エンジン・インバータ異常を告知させる。この告知によって利用者は、異常を知ることができる。
【００４８】
そして、ステップＳ８１４で温度センサ１０の検出温度が６０℃を超えている場合、暖機運転が正常に行われたことを表し、ステップＳ８１８に移行し、三方弁３０をＢ−Ｃ方向に切り換え、バイパス路２８を切り離した後、メインルーチン（図４）のステップＳ９に移行し、エンジン２による発電とともに、排熱回収を開始する。
【００４９】
次に、図１６は、図４のステップＳ９のサブルーチンであるエンジン入温度制御（目標値６５℃の制御）を示している。
【００５０】
ステップＳ９０１ではエンジン２が運転状態か否かを常に監視し、ステップＳ９０２では循環ポンプ４５の回転制御等を実行する。即ち、エンジン２に対する熱媒４の入側温度、即ち、温度センサ８の検出温度である戻り温度が所定温度、例えば、６５℃を目標値として循環ポンプ４５の回転制御を行う。なお、この制御の結果、循環ポンプ４５の回転が停止している場合には、三方弁４４をＡ−Ｃ方向に切り換え（閉）、循環ポンプ４５が回転している場合は三方弁４４をＤ−Ｂ方向に切り換えた後、ステップＳ９０３に移行する。
【００５１】
ステップＳ９０３では、貯湯タンク３４の最下部側の温度センサ６５０の検出温度が所定温度、例えば、５０℃以上か否かを判定し、所定温度以下の場合、ステップＳ９０４に移行する。この場合、始動条件とのヒステリシス温度は例えば、１０℃に設定する。そして、ステップＳ９０４では、エンジン２に対する熱媒４の入側温度、即ち、温度センサ８の検出温度である戻り温度が所定温度、例えば、７５℃以上が所定時間、例えば、１０秒以上か否か、且つ、循環ポンプ４５の回転数が最大か否かを判定する。所定温度が所定時間以下、且つ、循環ポンプ４５の回転数が最大でない場合、ステップＳ９０５に移行する。
【００５２】
ステップＳ９０５では、エンジン２の運転状態が停止か否かを判定し、エンジン２が停止していないとき、即ち、運転状態のとき、ステップＳ９０６に移行し、暖房接点がＯＮ状態か否かを判定する。ＯＮ状態でない場合には、ステップＳ９０７に移行し、エンジン運転が許可されているか否かを判定し、エンジン運転が許可されている場合には、ステップＳ９０８に移行してタンク蓄熱量が（給湯負荷×１．２−積算出力）より多いか否かを判定する。即ち、この判定は、暖房を行っていない場合、エンジン運転許可時間内であれば、この条件成立でエンジン運転停止を行うことを意図している。
【００５３】
ところで、ステップＳ９０３で温度センサ６５０の検出温度が所定温度、即ち、５０℃を超えている場合、又は、ステップＳ９０４で所定温度が所定時間以上、且つ、循環ポンプ４５の回転数が最大である場合には、ステップＳ９０９に移行し、循環ポンプ４５を停止させ、ステップＳ９１０に移行してエンジン停止を行う。ステップＳ９１１では、エンジン停止から所定時間の経過、例えば、３０秒が経過するまで待機した後、ステップＳ９１２に移行し、循環ポンプ１６を停止させた後、図４に示すメインルーチンのステップＳ２に戻る。即ち、循環ポンプ４５を停止させた後、循環ポンプ１６を停止させるのは、貯湯タンク３４側の階層蓄熱の崩れを防止するためである。
【００５４】
また、ステップＳ９０５でエンジン停止、ステップＳ９０７でエンジン運転禁止、又は、ステップＳ９０８でタンク蓄熱量が（給湯負荷×１．２−積算出力）を超えている場合には、ステップＳ９１３に移行し、エンジン停止を行い、ステップＳ９１４でエンジン停止から所定時間例えば、３０秒が経過するまで待機した後、ステップＳ９１５に移行し、循環ポンプ４５の停止を行い、ステップＳ９１２に移行する。
【００５５】
そして、この排熱回収制御装置では、エンジン２の冷却回路を構成する排熱回収路６に排熱回収用の熱交換器２４、暖房用の熱交換器２６を設置しているので、温水３２、９８に排熱を効率よく吸収させることができ、温水３２を貯湯タンク３４に導いて蓄熱させ、温水９８を暖房用循環路１００に流すことができる。
【００５６】
ところで、エンジン２の能力や耐久性を保つには、エンジン２からの排熱吸収には限度があり、熱媒４の戻り温度は一定温度、例えば、６５℃を中央値として一定温度幅、例えば、６５±５℃程度に維持することが望ましいものであるが、実際には、室内放熱器１０２、浴室暖房乾燥機１０４の運転状態や運転台数等で暖房負荷の変化や、外部からの給水温度等でエンジン２に戻る熱媒４の戻り温度は大きく変動する。そこで、排熱回収路６側の熱媒４の循環流量の制御と、循環路３６側の温水３２の循環流量の制御とを併用して熱媒４の戻り温度を制御する。この場合、例えば、消費電力が低く、制御性の良い直流モータ１７で駆動される循環ポンプ１６や、同様に、直流モータ４７で駆動される循環ポンプ４５を使用すれば、熱媒４や温水３２の流量を暖房負荷の増減に応じて幅広く調整することができ、熱媒４の戻り温度を最適化することができる。
【００５７】
この場合、暖房要求がないとき、熱交換器２４のみで熱交換が行われるので、この熱交換に応じてエンジン２への熱媒４の戻り温度が所定温度、例えば、６５℃となるように循環ポンプ４５の回転数を制御して流量を調整し、貯湯タンク３４への蓄熱を行う。
【００５８】
また、暖房要求があったとき、暖房端末の放熱負荷の大きさで熱媒４の戻り温度が変動するが、その戻り温度が所定温度以下、例えば、６５℃以下の場合、熱交換器２４での熱回収は不要であるため、循環ポンプ４５を停止し、熱媒４の戻り温度が所定温度、例えば、６５℃を超える場合、循環ポンプ４５を運転させ、熱媒４の戻り温度が所定温度、即ち、６５℃となるように温水流量を調整し、貯湯タンク３４へ蓄熱を行う。
【００５９】
しかし、暖房要求において、低温水で十分な低温要求の場合、例えば床暖房の場合には、その暖房端末には６０℃程度の温水循環で十分である。このような低い温度要求について、エンジン２への熱媒４の戻り温度は６５℃であり、エンジン２からの往き温度は７５℃であるため、熱交換器２６では６０℃を超える熱交換が行われる。このような高温の温水９８を循環させると、床暖房パネルは過熱状態となり、好ましくない。
【００６０】
そこで、低温（６０℃）の暖房要求の場合には、エンジン２の熱媒４の戻り温度を低温要求に最適な戻り温度、例えば、６０℃、往き温度を７０℃にシフトさせるように循環ポンプ４５の回転を制御し、温水３２の流量を調整する。即ち、温水３２の流量を増加させると、排熱回収熱量が増加し、エンジン２の排熱回収路６の熱媒４の温度が低下することになる。
【００６１】
【発明の効果】
以上説明したように、本発明によれば、次の効果が得られる。
ａ 暖房負荷に応じて熱源に循環する熱媒の温度を制御するので、暖房端末側に供給される熱と、熱源側の排熱回収とを最適化することができ、暖房端末側の過熱状態や熱源側の運転状態の悪化を防止することができる。
ｂ 高温要求がない場合にエンジンへの戻り温度（冷却温度）を低めに設定することで、エンジンの熱効率が上がり、経済性や耐久性を向上させることができる。
ｃ 直流モータで駆動するポンプを用いたので、消費電力の低減を図ることができ、暖房負荷に応じてエンジンの排熱回収を自由に制御できる。
【図面の簡単な説明】
【図１】本発明の排熱回収制御装置の実施例を示す図である。
【図２】本発明の排熱回収制御装置の実施例を示す図である。
【図３】図１の排熱回収制御装置の一部を拡大して示した図である。
【図４】排熱回収制御動作を示すフローチャートである。
【図５】貯湯タンクの蓄熱形態を示す図である。
【図６】メインルーチンにおける弁初期位置の設定処理に関するサブルーチンを示すフローチャートである。
【図７】メインルーチンにおけるエンジン異常停止処理に関するサブルーチンを示すフローチャートである。
【図８】メインルーチンにおけるエンジン運転許可処理に関するサブルーチンを示すフローチャートである。
【図９】メインルーチンにおけるエンジン停止処理に関するサブルーチンを示すフローチャートである。
【図１０】メインルーチンにおけるエンジン強制停止処理に関するサブルーチンを示すフローチャートである。
【図１１】メインルーチンにおける暖房命令処理に関するサブルーチンを示すフローチャートである。
【図１２】メインルーチンにおける給湯積算出力カウンタ処理に関するサブルーチンを示すフローチャートである。
【図１３】メインルーチンにおける弁異常チェック処理に関するサブルーチンを示すフローチャートである。
【図１４】メインルーチンにおける温度センサ異常チェック処理に関するサブルーチンを示すフローチャートである。
【図１５】メインルーチンにおけるエンジン起動処理及び暖機運転処理に関するサブルーチンを示すフローチャートである。
【図１６】メインルーチンにおけるエンジン入温度６５℃制御に関するサブルーチンを示すフローチャートである。
【符号の説明】
２ エンジン（熱源）
４ 熱媒
６ 排熱回収路
１６、４５ 循環ポンプ
１７、４７ 直流モータ
２４、２６ 熱交換器
３２、９８ 温水
１０２ 室内放熱器（暖房端末）
１０４ 浴室暖房乾燥機（暖房端末）
１２４ 制御部（制御手段）[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an exhaust heat recovery control device that uses a drive source such as an engine driving a generator as a heat source and recovers and uses the exhaust heat.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, there is known an exhaust heat recovery control device that generates electric power by driving a generator with an engine and recovers and uses exhaust heat of an engine that is a driving source. The exhaust heat recovery is performed through a cooling medium or a heat medium as exhaust heat recovery water flowing through the water jacket portion of the engine and through the heat medium. Then, the heat absorption of the heat medium is accumulated, or the heat is used for hot water supply or the like.
[0003]
[Problems to be solved by the invention]
By the way, circulating the fluid such as the heat medium to the driving source such as the engine to absorb the exhaust heat is to cool the driving source, and excessive or insufficient cooling deteriorates the driving characteristics of the driving source. The operation efficiency may be lowered and the durability may be impaired. In particular, warm water can be warmed with the recovered exhaust heat, and this hot water can be used for heating such as floor heating, but depending on the heating terminal, it is expected that the heating temperature will rise abnormally due to the absorbed exhaust heat, Use efficiency of exhaust heat may be deteriorated.
[0004]
Accordingly, an object of the present invention is to provide an exhaust heat recovery control device that optimizes exhaust heat recovery from a heat source such as an engine in accordance with a heating load.
[0005]
[Means for Solving the Problems]
The exhaust heat recovery control device of the present invention includes a heat source (engine 2) that releases heat, a heat medium (4) that circulates through the heat source, and an exhaust heat recovery path that recovers the exhaust heat of the heat source to the heat medium ( 6), pumps (circulation pumps 16 and 45) that rotate by a motor and circulate the heat medium to the heat source through the exhaust heat recovery path, and heating by heat radiation of hot water (98) heated by the heat of the heat medium to heating terminal (indoor radiator 102, bathroom heater dryer 104) and the heat of the heating medium circulating in the exhaust heat recovery passage and the heat exchange with the hot water, pressurized heat heat exchanger the hot water (26) And temperature detection means for detecting the temperature of the heat medium returning to the heat source through the exhaust heat recovery path or the temperature of the heat medium exiting from the heat source , and rotational control of the motor according to the operation of the heating terminal. circulating the heat source by the pump went And adjusting the flow rate of the serial heat medium performs a control for detecting the temperature of the heating medium back to the heat source to shift to a predetermined temperature, during the start-up operation or the warm-up operation of the heat source prior to transfer of this control, the heat source Control means (control unit 124) for determining whether or not the detected temperature of the heating medium coming out of the vehicle exceeds a predetermined temperature and generating an output indicating the abnormality when the predetermined temperature is continued for a predetermined time It is characterized by comprising.
[0006]
In the exhaust heat recovery control apparatus of the present invention, the heating terminal is a low temperature required load such as a floor heating panel using hot water as a heat source, a high temperature required load such as a fan convector, and the like. One or a plurality of the heating terminals are installed, and the load on the heat source side such as the exhaust heat recovery path varies greatly depending on the operation state and the number of the operation. Therefore, if the temperature of the heat medium circulating to the heat source is controlled by controlling the pump rotation speed according to the operation of the heating terminal, the heat supplied to the heating terminal side and the exhaust heat recovery on the heat source side are optimized. can do. As a result, it is possible to prevent deterioration of the overheating state on the heating terminal side and the operation state on the heat source side. Then, it is determined whether or not the detected temperature of the heat medium coming out of the heat source exceeds a predetermined temperature. If the predetermined temperature is continued for a predetermined time, an abnormality is generated and an output indicating the abnormality is generated .
[0007]
In the exhaust heat recovery control apparatus of the present invention, the control means controls the number of revolutions of the pump according to the operation of the heating terminal, and changes the return temperature of the heat medium circulating to the heat source. To do. That is, if the pump rotation speed is controlled, the exhaust heat absorption from the heat source changes, and the return temperature can be adjusted. In this invention, the operating efficiency of the heat source can be increased by changing the return temperature, for example, by lowering the return temperature of the heat medium to the heat source.
[0008]
In the exhaust heat recovery control apparatus of the present invention, the pump is driven by a DC motor (17, 47). That is, a DC pump driven by a DC motor has low power consumption, excellent controllability, and can control a wide heat medium flow rate from a small flow rate to a large flow rate.
[0009]
In the exhaust heat recovery control apparatus of the present invention, a drive source that rotates a generator is used as the heat source. That is, the drive source for driving the generator is composed of, for example, an engine, has a considerable amount of exhaust heat, and becomes an effective heat source.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to examples shown in the drawings.
[0011]
1 to 3 show an embodiment of the exhaust heat recovery control device of the present invention, FIG. 1 shows an exhaust heat recovery system such as an engine and a hot water storage tank of the exhaust heat recovery control device, and FIG. 2 shows an exhaust heat recovery control device. FIG. 3 shows an enlarged portion of the exhaust heat recovery control device of FIG. 1, such as a heat storage utilization system such as a heating terminal.
[0012]
In this exhaust heat recovery control device, an engine 2 as a drive source for driving a generator (not shown) is used as a heat source for releasing heat. The engine 2 uses engine cooling water or exhaust heat as a fluid for exhaust heat recovery. An exhaust heat recovery path 6 for circulating the heat medium 4 as recovered water and recovering the exhaust heat of the engine 2 in the heat medium 4 is formed. Temperature sensors 8 and 10 including a thermistor or the like are provided as temperature detecting means on the inlet side and the outlet side of the engine 2 of the exhaust heat recovery path 6, and a bypass path 12 is formed via a three-way valve 14. ing. The exhaust heat recovery path 6 includes a circulation pump 16 for forcibly circulating the heat medium 4, a circulation tank 18 that supplies the heat medium 4 to the exhaust heat recovery path 6, and an electric heater that heats the heat medium 4 with power generation output. 20, a flow sensor 22, first and second heat exchangers 24, 26, and the like are provided, and a bypass path 28 for shortening the circulation path during warm-up is a three-way valve, apart from the bypass path 12. 30 is formed. The circulation pump 16 is driven by a DC motor 17.
[0013]
The heat exchanger 24 is a heating means for hot water 32 using the heat medium 4 as a heat source, and is provided in a circulation path 36 as an exhaust heat recovery path for circulating water to be heated in a hot water storage tank 34 that is a heat storage means. . The circulation path 36 forms a closed circuit that connects the bottom surface side and the ceiling side of the hot water storage tank 34, and is provided with bypass paths 38, 40, and a flow path switching means for the bypass paths 38, 40. Are provided with three-way valves 42, 44, a heat exchanger 24, a flow sensor 43, a circulation pump 45, a temperature sensor 49, and the like. That is, the circulation pump 45 is driven by the DC motor 47, and the hot water 32 heated by the heat exchanger 24 is supplied to the upper layer side of the hot water storage tank 34 where the stacked boiling is performed. The hot water storage tank 34 is provided with a first buffer plate 46 as a means for preventing turbulent heat accumulation in the hot water 32 supplied and taken out.
[0014]
A water supply channel 48 is provided on the bottom surface side of the hot water storage tank 34, and a drain plug 50 is provided, so that clean water W is supplied from the water supply pipe 52 to the bottom surface side of the hot water storage tank 34. The water supply pipe 52 is provided with a pressure reducing valve 54 and a flow rate sensor 56, and a hot water supply pipe 60 is connected via a mixing valve 58. Further, the hot water storage tank 34 is provided with a second buffer plate 62 as a means for preventing turbulent heat storage due to water supply. A plurality of temperature sensors 641, 642,... 650 are installed at regular intervals on the side surface of the hot water storage tank 34 as temperature detecting means for detecting the temperature of the water that is stacked and heated. In this embodiment, ten temperature sensors 641, 642,... 650 are installed, but fewer or more may be installed depending on the measurement zone.
[0015]
Further, a hot water outlet path 66 is provided on the ceiling side of the hot water storage tank 34, and one end of the hot water outlet path 66 is opened to the outside air via an overpressure relief valve 68 and a negative pressure valve 70, and on the other end side. Are provided with a third heat exchanger 72 for hot-water supply backup, a temperature sensor 74 for detecting the hot water temperature, and the like. The heat exchanger 72 uses the heat of combustion of the fuel gas by the burner 76 as a heat source. The hot water supply pipe 60 on the outlet side of the heat exchanger 72 is provided with the mixing valve 58, the flow rate sensor 78, the water proportional valve 80, the temperature sensor 82 for detecting the mixed temperature, and the like.
[0016]
Moreover, the hot water HW discharged from the hot water supply pipe 60 is supplied to the side of the recirculation circuit 84 and can be poured into the bathtub 86. A three-way valve 88, a circulation pump 90, a water level sensor 92, a temperature sensor 94, a fourth heat exchanger 96, and the like are provided on the side of the circulation path 84 for remedy.
[0017]
The heat exchanger 26 provided in the exhaust heat recovery path 6 is a heating means for hot water 98 as a heating heat medium using the heat medium 4 as a heat source, and is provided in the heating circulation path 100. The heating circulation path 100 is a means for circulating hot water 98 to heating terminals such as the indoor radiator 102 and the bathroom heater / dryer 104, and the hot water tank 106 serves as a means for accumulating the hot water 98 and suppressing expansion boiling. A circulation pump 108, a flow sensor 110, heat exchangers 96 and 112, and the like are provided. A water supply pipe 114 is connected to the hot water tank 106 and a valve 116 for adjusting the water supply is provided. The level sensor 118 is used for level control for storing an appropriate amount of hot water 98 in the hot water tank 106. The heat exchanger 112 uses the combustion heat of the fuel gas from the burner 120 as a heat source, and is used for back-up heating of the hot water 98 as a heating heat source in addition to the reheating of the hot water 122 in the bathtub 86. The heat exchanger 96 is used to heat the heat of the hot water 98 for the memory circuit 84.
[0018]
In this exhaust heat recovery control device, the switching direction A, B, C or D of the three-way valve 14, 30, 42, 44 is shown in FIG. 3, for example, during the warm-up operation, the three-way valve 14 is C-A. Direction, the three-way valve 30 is switched to the C-A direction. At this time, in order to prevent natural convection of the hot water 32, the three-way valve 42 is switched to the D-A direction and the three-way valve 44 is switched to the DC (closed) direction. .
[0019]
A control unit 124 configured by a computer or the like is installed as the exhaust heat recovery control unit. The control unit 124 includes a CPU as a calculation unit, a ROM and a RAM as storage units, and a drive output and a detection output. An input / output unit is provided with I / O and the like, and a hot water supply integration output counter 125 is provided as a hot water supply integration unit. The control executed by the control unit 124 includes rotation control of the DC motors 17 and 47, rotation control of the circulation pumps 16 and 45, opening / closing control of the three-way valves 42 and 44, and the like according to the operation state of the heating terminal. In order to perform such control, detection outputs from various sensors such as the temperature sensors 8 and 10 and the flow rate sensor 22 are added to the control unit 124 as control inputs, and the control output obtained from the control unit 124 is the DC motor 17. , 47 and three-way valves 42 and 44, etc., are added to actuators of various control devices. Further, the control unit 124 is provided with a display 126 as a display means for displaying an alarm or the like, and the display 126 can be constituted by a character display, a sound generator or the like. In this embodiment, in order to perform digital control, the control unit 124 using a computer or the like is described as an example. However, a control circuit that performs analog processing may be used.
[0020]
Next, the main routine of the exhaust heat recovery control operation will be described with reference to the flowchart shown in FIG.
[0021]
When the power is turned on, in step S1, various valves such as the three-way valves 14, 30, 42, and 44 are set to initial positions, and then the process proceeds to step S2. In step S2, a constant activation program is executed. This always-start program includes engine abnormal stop control, engine operation permission control, engine stop control, engine forced stop control, heating command control, hot water supply integrated output counter 125 control, valve abnormality check control, temperature sensor abnormality check control, and the like. Is called. In step S3, it is determined whether or not a heating command has been given to the control unit 124. If there is no heating command, the process proceeds to step S4 to determine whether or not engine operation is permitted. That is, it is confirmed in step S4 whether it is within the operation permission time set according to the season.
[0022]
When engine operation is permitted in step S4, the process proceeds to step S5, and it is determined whether the required heat storage amount is equal to or greater than a predetermined heat storage amount. That is, in step S5, for example,
(Hot-water supply load × 1.2−integrated output−tank heat storage amount)> 1000 kcal (1)
If the value obtained by subtracting the heat storage amount of the hot water storage tank 34 from the predicted hot water supply demand is equal to or greater than the predetermined heat storage amount, the engine 2 can be operated. In this case, the coefficient 1.2 is an example of a numerical value for giving a margin to the hot water supply load, and is not limited to this numerical value.
[0023]
Here, the “hot water supply load” used for the calculation in step S5 is to determine the expected hot water supply load for each season in advance.
[0024]
[Table 1]

[0025]
That is, the “hot water supply load” is an estimated amount of hot water supply in the next season and time, so for example, when starting CGS operation at 18:00 on July X, the hot water supply load is calculated at 6000 kcal, In addition, when the CGS operation is started at 5:00 on February Y, the hot water supply load is calculated at 2000 kcal.
[0026]
The “integrated output” is the total of the outputs used for hot water supply and pouring obtained using the hot water supply integrated output counter 125 built in the control unit 124. That is, all outputs including backup and heat storage use are obtained in a time zone where there is a demand for hot water supply, and the data is fed back to the engine operation time.
[0027]
Moreover, the calculation of the tank heat storage amount of the hot water storage tank 34 is, for example, a tank capacity of 200 liters, and as shown in FIG. 5, the zones 1 to 7 of the hot water storage tank 34 have the same capacity, and the amount of hot water per zone Is about 28.6 liters. Here, if the water temperature is defined as 5 ° C. in winter, 15 ° C. in spring / autumn, and 25 ° C. in summer, the calorific value Q (kcal) of each zone is
[0028]
Q = 28.6 × {(upper detection temperature + lower detection temperature) / 2−water temperature} (2)
Thus, the tank heat storage amount Qm is the sum of all zones 1 to 7. However, if one condition is {(upper detection temperature + lower detection temperature) / 2−water temperature} <10 ° C., the zone is zero. For example, in winter, when the detected temperature of the temperature sensor 641 is 75 ° C. and the detected temperature of the temperature sensor 643 is 70 ° C., the heat quantity Q _{1 of the} zone ₁ is
[0029]
Q ₁ = 28.6 × {(75 + 70) / 2−5} = 1930.5 (kcal) (3)
It becomes. Of the temperature sensors 641 to 650, the temperature sensors 642 and 649 are not used for calculating the heat storage amount Qm.
[0030]
And when it determines with the said required heat storage amount being 1000 kcal or more by step S5, or when the heating command is issued by step S3, it transfers to step S6 and the temperature sensor 650 of the lowest side of the hot water storage tank 34 is shown. It is determined whether the detected temperature is a predetermined temperature, for example, 40 ° C. or higher. If the detected temperature is not higher than the predetermined temperature, the process proceeds to step S7. In step S7, it is determined whether or not a predetermined time, for example, 60 minutes or more has elapsed since the previous stop of the engine 2, and if it is less than the predetermined time, startup of the engine 2 is prohibited to protect the engine. That is, it is confirmed that the hot water temperature on the lowermost side of the hot water storage tank 34 is low, and overheating of the engine 2 is prevented. And when predetermined time has passed, it transfers to step S8, and while starting the engine 2, warm-up operation is performed. In this warm-up operation, the three-way valve 30 is switched to narrow the exhaust heat recovery path 6 via the bypass path 28, and the heat medium temperature rises rapidly.
[0031]
Then, after this warm-up operation, the process proceeds to step S9, and the temperature of the heat medium 4 on the inlet side of the engine 2 is controlled to be a predetermined temperature, for example, 65 ° C. This constant temperature control is performed by increasing / decreasing the number of rotations of the DC motor 17 while monitoring the temperature detected by the temperature sensors 8, 10 and increasing / decreasing the flow rate of the heat medium 4 pumped by the circulation pump 16.
[0032]
Next, FIG. 6 shows a subroutine for setting initial valve positions of the three-way valves 14, 30, 42, 44, etc. in step S1 of FIG. That is, when this subroutine starts, in step S101, the three-way valve 42 is in the D-A direction, the three-way valve 44 is in the DC (closed) direction, the three-way valve 30 is in the C-A direction, and the three-way valve 14 is in the C-A direction. Can be switched to. As a result, execution of the always-start program is prepared.
[0033]
Next, FIG. 7 shows engine abnormal stop control which is a subroutine of step S2 of the main routine of FIG. That is, when this subroutine is started, in step S201, it is determined whether or not the operating state of the engine 2 is “operating”. If it is in the operating state, the process proceeds to step S202, and a predetermined time, for example, 10 seconds elapses. After that, the process proceeds to step S203, where it is determined whether or not the gas valve is closed (OFF). If not, the process returns to step S201, and if it is closed, the process proceeds to step S204 to stop the engine. In step S205, an alarm is displayed on the display 126 as a display indicating that the engine has been stopped abnormally.
[0034]
If it is determined in step S201 that the engine 2 is not in an operating state, the process proceeds to step S206, and for example, after a lapse of 10 seconds, the process proceeds to step S207 and the gas valve is open (ON). If it is not open, the process returns to step S201. If it is open, the process proceeds to step S208, the engine is stopped, then the process proceeds to step S209, and the display 126 indicates “Do not stop the engine”. Alarm display is performed.
[0035]
Next, FIG. 8 shows engine operation permission control which is a subroutine of step S2 of the main routine of FIG. That is, when this subroutine is started, it is determined in step S211 whether or not the engine operation is permitted time. If it is in the operation permitted time, the process proceeds to step S212 and "permitted" is output as an engine operation permission instruction. On the other hand, if it is not the engine operation permission time, the process proceeds to step S213, and “prohibited” is output as an instruction to prohibit engine operation permission.
[0036]
Next, FIG. 9 shows engine stop control which is a subroutine of step S2 of the main routine of FIG. That is, when this subroutine starts, in step S215, the power of the engine 2 is turned off, and then the process proceeds to step S216. After the initial valve position control (FIG. 6) is executed, the process proceeds to step S217. Set the operation state to the stop state.
[0037]
Next, FIG. 10 shows engine forced stop control which is a subroutine of step S2 of the main routine of FIG. That is, when this subroutine is started, in step S221, for example, it is determined whether or not the Esc key is pressed as the forced stop input means. When this Esc key is pressed, the process proceeds to step S222, and engine stop control ( 9) is executed, and the control is terminated.
[0038]
Next, FIG. 11 shows heating operation command control which is a subroutine of step S2 of the main routine of FIG. That is, when this subroutine is started, in step S225, it is determined whether or not the terminal switch is turned on as a heating command means on the heating device side or a heating command for two-way communication is turned on. The process proceeds to S226, where the heating command is set to “ON”, and the E-con terminal of the backup intelligent board that is the control means is set to “ON”. Further, in step S227, it is determined whether or not the terminal switch OFF and the two-way communication heating command OFF are established as the heating command means on the heating device side. When the heating stop command is instructed, The process proceeds to S228, where the heating command is set to “OFF”, and the E-con terminal of the backup intelligent board as the control means is set to “OFF”.
[0039]
Next, FIG. 12 shows control of the hot water supply integrated output counter 125, which is a subroutine of step S2 of the main routine of FIG. That is, when this subroutine is started, in step S231, it is determined whether or not the engine operation is “permitted”. If permitted, the process proceeds to step S232 to reset the counter. That is, after setting the amount of heat Qc stored in the hot water supply integrated output counter 125 to 0 kcal, the process proceeds to step S233 to determine the water temperature. That is, after setting 5 ° C. in the winter, 15 ° C. in the spring and autumn, and 25 ° C. in the summer, the process proceeds to step S234, and the hot water temperature of the temperature sensor 82 that is a mixed temperature thermistor is measured.
[0040]
In step S235, the flow rate sensor 78 that detects the amount of hot water supply determines whether, for example, 1 liter is counted as a predetermined flow rate. If 1 liter is counted, the process proceeds to step S236. In step S236, the hot water supply integrated output heat quantity Qc is calculated as the heat quantity calculation per liter. That is, this hot water supply integrated output heat quantity Qc (kcal) is
Qc = (hot water temperature-water temperature) × 1 (kcal) (4)
Is calculated by
[0041]
Then, the process proceeds to step S237, where it is determined whether or not the engine operation permission is “prohibited”. When the engine operation is prohibited, the process returns to step S231, and when the engine operation is not prohibited. The process proceeds to step S234, and the processes of step S234 to step S236 are executed.
[0042]
Next, FIG. 13 shows valve abnormality check control which is a subroutine of step S2 of the main routine of FIG. That is, when this subroutine is started, in step S241, it is determined whether or not the valve output and the limit indicating the switching state coincide with each other. If they do not coincide, for example, 30 seconds have passed as a predetermined time in step S242. Thereafter, the process proceeds to step S243, and the display 126 is notified by an alarm that the three-way valves 14, 30, 42, 44, etc. are abnormal. If the valve output and the limit coincide with each other in step S241, the process proceeds to step S244 to output a normal message and display it on the display 126.
[0043]
Next, FIG. 14 shows temperature sensor abnormality check control which is a subroutine of step S2 of the main routine of FIG. That is, when this subroutine is started, in step S251, it is determined whether a disconnection or short circuit abnormality has occurred in the connection line or the like. If an abnormality has occurred, the process proceeds to step S252, and the display 126 displays the temperature. An alarm notifies that the sensors 8, 10, etc. are abnormal. If no abnormality has occurred in step S251, the process proceeds to step S253 to output a normal message and display it on the display 126.
[0044]
Next, FIG. 15 shows control of engine start-up and warm-up operation, which is a subroutine of step S8 of the flowchart shown in FIG.
[0045]
In step S801, in order to prevent natural convection of the hot water 32, the three-way valve 42 is set in the DA direction, the three-way valve 44 is set in the DC (closed) direction, and a warm-up circuit is formed. Direction, the three-way valve 14 is switched to the C-A direction, and the circulation pump 16 is set to the middle rotation. Then, the process proceeds to step S802, and whether or not the temperature detected by the temperature sensor 10 is a predetermined temperature, for example, 55 ° C. or less. If the temperature exceeds 55 ° C., the process proceeds to step S803, and it is determined whether, for example, 20 minutes have passed as a predetermined time from the start of the precheck. If 20 minutes have passed after exceeding 55 ° C., it is expected that some abnormality has occurred. Therefore, the process proceeds to step S804, an alarm is generated on the display 126, and “abnormal stop” is notified. To do. At this time, the engine 2 is shifted to the stop mode.
[0046]
If the detected temperature is equal to or lower than the predetermined temperature in step S802, the process proceeds to step S805 and the power supply of the engine 2 is turned on. The process proceeds to step S806 and the engine start contact is turned on for a predetermined time, for example, 5 seconds. Then, after turning off the engine starting contact point, the system waits for a predetermined time, for example, 3 seconds, and proceeds to step S808. In step S808, it is determined whether or not the gas valve is in an ON state. If the gas valve is not in an ON state, the process proceeds to step S809 to determine whether or not the activation is a predetermined number of times, for example, the fifth time. If it is less than or equal to the predetermined number, the process proceeds to step S810, waits for a predetermined time to shift to the predetermined number of times, for example, 5 seconds, and returns to step S806. If the engine has reached the predetermined number of times in step S809, the process proceeds to step S811, the engine is stopped, an alarm is generated on the display 126 in step S812, and the engine start failure is notified. This notification allows the user to know the abnormality.
[0047]
When it is determined in step S808 that the gas valve has been turned ON, the process proceeds to step S813, the engine 2 enters the operating state, and the process proceeds to step S814. In step S814, it is determined whether or not the detected temperature of the temperature sensor 10 exceeds a predetermined temperature, for example, 60 ° C., and if it does not exceed 60 ° C., the process proceeds to step S815 to elapse a predetermined time, for example, 20 minutes. Whether or not has elapsed has been determined, and the transition of the detected temperature is monitored until a predetermined time has elapsed. If the detected temperature does not exceed 60 ° C. even after 20 minutes have elapsed, the process proceeds to step S816, the engine is stopped, and then the process proceeds to step S817 to generate an alarm on the display 126. Announce engine / inverter abnormality. This notification allows the user to know the abnormality.
[0048]
And when the detection temperature of the temperature sensor 10 exceeds 60 degreeC by step S814, it represents that warming-up operation was performed normally, it transfers to step S818, and the three-way valve 30 is switched to a BC direction, After the bypass path 28 is disconnected, the process proceeds to step S9 of the main routine (FIG. 4), and exhaust heat recovery is started together with power generation by the engine 2.
[0049]
Next, FIG. 16 shows engine input temperature control (control of target value 65 ° C.), which is a subroutine of step S9 of FIG.
[0050]
In step S901, it is always monitored whether or not the engine 2 is in an operating state, and in step S902, rotation control of the circulation pump 45 is executed. That is, the rotation temperature of the circulation pump 45 is controlled by setting the inlet temperature of the heat medium 4 to the engine 2, that is, the return temperature detected by the temperature sensor 8 as a target value, for example, 65 ° C. As a result of this control, when the rotation of the circulation pump 45 is stopped, the three-way valve 44 is switched (closed) in the direction AC, and when the circulation pump 45 is rotating, the three-way valve 44 is set to D. After switching to the -B direction, the process proceeds to step S903.
[0051]
In step S903, it is determined whether the temperature detected by the temperature sensor 650 on the lowermost side of the hot water storage tank 34 is a predetermined temperature, for example, 50 ° C. or higher. If the temperature is not higher than the predetermined temperature, the process proceeds to step S904. In this case, the hysteresis temperature with respect to the starting condition is set to 10 ° C., for example. In step S904, whether or not the temperature at which the heating medium 4 enters the engine 2, that is, the return temperature detected by the temperature sensor 8 is a predetermined temperature, for example, 75 ° C. or more is a predetermined time, for example, 10 seconds or more. And it is determined whether the rotation speed of the circulation pump 45 is the maximum. When the predetermined temperature is equal to or less than the predetermined time and the rotation speed of the circulation pump 45 is not the maximum, the process proceeds to step S905.
[0052]
In step S905, it is determined whether or not the operating state of the engine 2 is stopped. When the engine 2 is not stopped, that is, when it is in the operating state, the process proceeds to step S906 to determine whether or not the heating contact is in the ON state. To do. If it is not ON, the process proceeds to step S907 to determine whether or not the engine operation is permitted. If the engine operation is permitted, the process proceeds to step S908 and the amount of heat stored in the tank becomes (hot water supply load). X1.2-integrated output). That is, this determination is intended to stop the engine operation when this condition is satisfied if the heating is not performed and the engine operation permission time is satisfied.
[0053]
By the way, when the detected temperature of the temperature sensor 650 exceeds a predetermined temperature, that is, 50 ° C. in step S903, or when the predetermined temperature is longer than a predetermined time and the rotation speed of the circulation pump 45 is maximum in step S904. In step S909, the circulation pump 45 is stopped. In step S910, the engine is stopped. In step S911, after waiting for a lapse of a predetermined time from the engine stop, for example, 30 seconds, the process proceeds to step S912, the circulation pump 16 is stopped, and then the process returns to step S2 of the main routine shown in FIG. . That is, the reason why the circulation pump 16 is stopped after the circulation pump 45 is stopped is to prevent collapse of the tiered heat storage on the hot water storage tank 34 side.
[0054]
Further, the engine is stopped at step S905, the engine operation inhibition in Step S907, or if the tank heat storage amount exceeds the (hot-water supply load × 1. 2-integrated output) at step S908, the process proceeds to step S913, the engine After stopping and waiting for a predetermined time, for example, 30 seconds, from the engine stop in step S914, the process proceeds to step S915, the circulation pump 45 is stopped, and the process proceeds to step S912.
[0055]
In this exhaust heat recovery control device, the heat exchanger 24 for exhaust heat recovery and the heat exchanger 26 for heating are installed in the exhaust heat recovery path 6 constituting the cooling circuit of the engine 2. 98 can efficiently absorb the exhaust heat, guide the hot water 32 to the hot water storage tank 34 to store the heat, and allow the hot water 98 to flow through the heating circuit 100.
[0056]
By the way, in order to maintain the capability and durability of the engine 2, there is a limit to the exhaust heat absorption from the engine 2, and the return temperature of the heat medium 4 is a constant temperature, for example, a constant temperature range with a central value of 65 ° C., for example, Although it is desirable to maintain the temperature at about 65 ± 5 ° C., in actuality, changes in the heating load depending on the operating state and the number of operating units of the indoor radiator 102 and bathroom heater / dryer 104, and the external water supply temperature The return temperature of the heat medium 4 that returns to the engine 2 due to the above or the like greatly varies. Therefore, the return temperature of the heat medium 4 is controlled by using both the control of the circulation flow rate of the heat medium 4 on the exhaust heat recovery path 6 side and the control of the circulation flow rate of the hot water 32 on the circulation path 36 side. In this case, for example, if the circulation pump 16 driven by the DC motor 17 with low power consumption and good controllability or the circulation pump 45 similarly driven by the DC motor 47 is used, the heat medium 4 and the hot water 32 are used. The flow rate of the heating medium 4 can be widely adjusted according to the increase or decrease of the heating load, and the return temperature of the heating medium 4 can be optimized.
[0057]
In this case, when there is no heating request, heat exchange is performed only by the heat exchanger 24, so that the return temperature of the heat medium 4 to the engine 2 becomes a predetermined temperature, for example, 65 ° C. according to this heat exchange. The number of revolutions of the circulation pump 45 is controlled to adjust the flow rate, and heat storage in the hot water storage tank 34 is performed.
[0058]
Further, when there is a heating request, the return temperature of the heating medium 4 varies depending on the size of the heat radiation load of the heating terminal. If the return temperature is lower than a predetermined temperature, for example, 65 ° C. or lower, the heat exchanger 24 Therefore, when the return temperature of the heating medium 4 exceeds a predetermined temperature, for example, 65 ° C., the circulating pump 45 is operated and the return temperature of the heating medium 4 is set to the predetermined temperature. That is, the hot water flow rate is adjusted to 65 ° C., and heat is stored in the hot water storage tank 34.
[0059]
However, in the case of a heating request, when the low-temperature water is sufficiently low, for example, in the case of floor heating, a hot water circulation of about 60 ° C. is sufficient for the heating terminal. For such a low temperature requirement, the return temperature of the heat medium 4 to the engine 2 is 65 ° C., and the outgoing temperature from the engine 2 is 75 ° C. Therefore, the heat exchanger 26 performs heat exchange exceeding 60 ° C. Is called. If such hot water 98 is circulated, the floor heating panel is overheated, which is not preferable.
[0060]
Therefore, in the case of a low temperature (60 ° C.) heating request, the circulation pump is configured to shift the return temperature of the heating medium 4 of the engine 2 to the optimum return temperature for the low temperature requirement, for example, 60 ° C. and the forward temperature to 70 ° C. The rotation of 45 is controlled and the flow rate of the hot water 32 is adjusted. That is, when the flow rate of the hot water 32 is increased, the amount of exhaust heat recovery heat increases, and the temperature of the heat medium 4 in the exhaust heat recovery path 6 of the engine 2 decreases.
[0061]
【The invention's effect】
As described above, according to the present invention, the following effects can be obtained.
a Since the temperature of the heat medium circulating to the heat source is controlled according to the heating load, the heat supplied to the heating terminal side and the exhaust heat recovery on the heat source side can be optimized, and the overheating state on the heating terminal side It is possible to prevent the deterioration of the operating state on the heat source side.
b When the return temperature (cooling temperature) to the engine is set lower when there is no high temperature requirement, the thermal efficiency of the engine is increased, and the economy and durability can be improved.
c Since a pump driven by a DC motor is used, power consumption can be reduced, and exhaust heat recovery of the engine can be freely controlled according to the heating load.
[Brief description of the drawings]
FIG. 1 is a diagram showing an embodiment of an exhaust heat recovery control apparatus of the present invention.
FIG. 2 is a diagram showing an embodiment of the exhaust heat recovery control apparatus of the present invention.
FIG. 3 is an enlarged view of a part of the exhaust heat recovery control device of FIG. 1;
FIG. 4 is a flowchart showing an exhaust heat recovery control operation.
FIG. 5 is a diagram showing a heat storage form of a hot water storage tank.
FIG. 6 is a flowchart showing a subroutine related to a valve initial position setting process in the main routine.
FIG. 7 is a flowchart showing a subroutine related to engine abnormal stop processing in the main routine.
FIG. 8 is a flowchart showing a subroutine related to engine operation permission processing in the main routine.
FIG. 9 is a flowchart showing a subroutine related to engine stop processing in the main routine.
FIG. 10 is a flowchart showing a subroutine related to engine forced stop processing in the main routine.
FIG. 11 is a flowchart showing a subroutine related to a heating command process in the main routine.
FIG. 12 is a flowchart showing a subroutine related to hot water supply integrated output counter processing in the main routine.
FIG. 13 is a flowchart showing a subroutine related to valve abnormality check processing in the main routine.
FIG. 14 is a flowchart showing a subroutine related to temperature sensor abnormality check processing in the main routine.
FIG. 15 is a flowchart showing a subroutine related to engine start-up processing and warm-up operation processing in a main routine.
FIG. 16 is a flowchart showing a subroutine regarding control of an engine input temperature of 65 ° C. in the main routine.
[Explanation of symbols]
2 Engine (heat source)
4 Heat medium 6 Waste heat recovery path 16, 45 Circulation pump 17, 47 DC motor 24, 26 Heat exchanger 32, 98 Hot water 102 Indoor radiator (heating terminal)
104 Bathroom heating dryer (heating terminal)
124 control unit (control means)

Claims (4)

A heat source that releases heat,
A heat medium is circulated through the heat source, and an exhaust heat recovery path for recovering the exhaust heat of the heat source to the heat medium;
A pump that rotates by a motor and circulates the heat medium to the heat source through the exhaust heat recovery path;
A heating terminal for heating by heat radiation of hot water heated by the heat of the heat medium ;
The heat of the heating medium circulating in the exhaust heat recovery passage and the heat exchange with the hot water, and the pressurized heat heat exchanger the hot water,
Temperature detection means for detecting the temperature of the heat medium returning to the heat source through the exhaust heat recovery path or the temperature of the heat medium exiting from the heat source;
In order to control the rotation of the motor in accordance with the operation of the heating terminal, adjust the flow rate of the heat medium circulating to the heat source by the pump, and shift the detected temperature of the heat medium returning to the heat source to a predetermined temperature At the time of start-up operation or warm-up operation of the heat source before this control shifts, it is determined whether or not the detected temperature of the heat medium coming out of the heat source exceeds a predetermined temperature, and the predetermined temperature is set to the predetermined temperature. A control means for generating an output indicating an abnormality when the time is continued ;
An exhaust heat recovery control device comprising:   2. The exhaust heat recovery control according to claim 1, wherein the control unit controls the number of revolutions of the pump according to the operation of the heating terminal and changes a return temperature of the heat medium circulating to the heat source. apparatus.   The exhaust heat recovery control device according to claim 1, wherein the pump is driven by a DC motor.   The exhaust heat recovery control device according to claim 1, wherein a driving source that rotates a generator is used as the heat source.

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