JP3977608B2 - Waste heat recovery control device - Google Patents

Description

【００３０】
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。
【００３１】
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。
【００３２】
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、
【００３３】
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、
【００３４】
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。
【００３５】
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。
【００３６】
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。
【００３７】
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。
【００３８】
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。
【００３９】
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）であ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。
【００４０】
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。
【００４１】
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。
【００４２】
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。
【００４３】
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。
【００４４】
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。
【００４５】
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、
【００４６】
Ｑｃ＝（湯温−水温）×１（ｋｃａｌ） ・・・（４）
で算出される。
【００４７】
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。
【００４８】
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。
【００４９】
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。
【００５０】
次に、図１５は、貯湯タンク３４の残熱を利用した暖房制御を示している。
【００５１】
この暖房制御はメインルーチンに対して割込み制御によって実行され、この制御がスタートすると、ステップＳ１１では、暖房要求があるか否かを判定し、暖房要求がない場合には、図４に示すメインルーチンに復帰し、暖房要求がある場合にはステップＳ１２に移行する。ステップＳ１２では、エンジン２が運転中であるか否かが判定され、エンジン２が運転中である場合には、通常の暖房シーケンスに移行する。また、エンジン２が運転中でない場合には、ステップＳ１３に移行し、貯湯タンク３４の残熱が所定熱量、例えば、２０００ｋｃａｌを超えているか否かが判定され、所定熱量以下の場合には通常の暖房シーケンスに移行し、所定熱量を超えている場合には、ステップＳ１４に移行する。ステップＳ１４では、貯湯タンク３４の温度センサ６４１の検出温度が所定温度を超えているか否か、例えば、６５℃を超えているか否かが判定され、超えていない場合には通常の暖房シーケンスに移行し、所定温度を超えている場合には、ステップＳ１５に移行する。
【００５２】
ステップＳ１５では、三方弁１４、４２、４４の切換え、循環ポンプ１６、４５の運転、暖房側の循環ポンプ１０８の運転、室内放熱器１０２、浴室暖房乾燥機１０４等の暖房端末側の熱動弁１１３、１１５を開とする。このような処理の後、ステップＳ１６では、貯湯タンク３４の温度センサ６４１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、超えていない場合には通常の暖房シーケンスに移行し、所定温度を超えている場合には、ステップＳ１７に移行する。
【００５３】
そして、ステップＳ１７では暖房要求があるか否かが判定され、暖房要求がない場合には図４のメインルーチンに復帰し、暖房要求がある場合にはステップＳ１６に戻り、ステップＳ１６の処理を行う。即ち、貯湯タンク３４の残熱量が所定熱量を超えている場合、即ち、温度センサ６４１の検出温度が所定温度、例えば、６０℃を超えている間、暖房要求があることを条件に貯湯タンク３４の温水３２の熱を用いた加熱によって暖房端末への温水供給を行う。
【００５４】
次に、図１６は、暖房凍結予防動作制御を示している。
【００５５】
この暖房凍結予防動作は、メインルーチンに対して割込み制御によって実行され、この制御がスタートすると、ステップＳ２１では温度センサ１２７が凍結が予想される所定温度以下であるか否か、例えば、６℃以下であるか否かを判定し、所定温度以下でない場合にはステップＳ２２に移行し、正常動作を続行し、所定温度以下である場合には、ステップＳ２３に移行する。ステップＳ２３では、暖房用の循環ポンプ１０８を運転するとともに、暖房用循環路１００の熱動弁１１３、１１５を開とした後、ステップＳ２４に移行する。
【００５６】
ステップＳ２４では排熱回収運転中であるか否かが判定され、運転中である場合にはステップＳ２５に移行し、凍結予防用の温度センサ１２７の検出温度が所定温度以上であるか否か、例えば、１０℃以上であるか否かを判定し、所定温度以上でない場合にはステップＳ２４に戻り、所定温度以上である場合にはステップＳ２６に移行し、所定時間として例えば、１６分だけ待機する。即ち、所定時間後、ステップＳ２７に移行し、循環ポンプ１０８を停止させ、熱動弁１１３、１１５を閉止し、凍結予防動作を終了する。即ち、排熱回収運転中は、排熱回収によって得られる熱量を凍結予防に利用する。
【００５７】
また、ステップＳ２４で排熱回収運転中でない場合にはステップＳ２８に移行し、貯湯タンク３４に凍結予防に必要な蓄熱量があるか否かが判定され、必要な蓄熱量がある場合には、ステップＳ２９に移行し、貯湯タンク３４内の温水３２を利用するための制御として、三方弁１４、４２、４４を切り換え、循環ポンプ１６及び循環ポンプ４５を運転状態に切り換え、ステップＳ３０に移行する。
【００５８】
ステップＳ３０では、温度センサ１２７の検出温度が所定温度以上か否か、例えば、１５℃以上か否かを判定し、所定温度以上である場合にはステップＳ３１に移行し、所定時間として例えば、１６分だけ待機する。即ち、所定時間後、ステップＳ３２に移行し、暖房用の循環ポンプ１０８、循環ポンプ１６、４５を停止するとともに、熱動弁１１３、１１５を閉止し、凍結予防動作を終了する。即ち、排熱回収運転中でない場合には、貯湯タンク３４に凍結防止に必要な蓄熱量が存在しているとき、その熱量を凍結予防に利用する。
【００５９】
しかし、ステップＳ２８で貯湯タンク３４に必要な蓄熱量が存在していない場合には、凍結防止のために必要な熱量を確保する必要がある。そこで、ステップＳ３３では、バックアップ燃焼としてバーナ１２０を燃焼させ、ステップＳ３４に移行し、温度センサ１２７の検出温度が所定温度以上か否か、例えば、２０℃以上か否かを判定する。所定温度以上でない場合には、ステップＳ２８に戻り、所定温度以上である場合にはステップＳ３５に移行し、バックアップ燃焼としてのバーナ１２０の燃焼を停止し、ステップＳ３６に移行して所定時間として例えば、１６分だけ待機する。即ち、所定時間後、ステップＳ３７に移行し、暖房用の循環ポンプ１０８を停止するとともに、熱動弁１１３、１１５を閉止し、凍結予防動作を終了する。即ち、排熱回収運転中でない場合であって、貯湯タンク３４に凍結防止に必要な蓄熱量が存在していないときには、バーナ１２０を燃焼させてその熱量を凍結予防に利用するものである。
【００６０】
このように、暖房要求があった場合には、エンジン２を運転して暖房を行うが、貯湯タンク３４内に必要な蓄熱量がある場合は、エンジン２を運転することなく、即ち、エンジン２を停止状態に維持し、貯湯タンク３４内の蓄熱を第２の熱媒である温水３２の熱を加熱源として、熱交換器２４を通して熱媒４を加熱する。この熱媒４をエンジン冷却回路である排熱回収路６を通じて熱交換器２６に循環させ、第３の熱媒である温水９８を加熱することにより暖房運転を行う。即ち、貯湯タンク３４の蓄熱を暖房に利用する。同様に、暖房用循環路１００及び暖房用温水器１２９の凍結防止の熱源に利用することができる。
【００６１】
このような処理を具体的に説明すると、室内放熱器１０２又は浴室暖房乾燥機１０４等の暖房端末側より暖房要求があると、熱交換器２４の入出側の三方弁４２、４４の方向を変え、循環ポンプ４５を動作させ、貯湯タンク３４の上部側から高温の温水３２を取り出し、熱交換器２４を通して貯湯タンク３４の下部側に流す。
【００６２】
同時に、三方弁１４の方向を変え、循環ポンプ１６を運転し、エンジン２側に熱媒４が循環しないように、エンジン２側の排熱回収路６をバイパス路１２で短絡状態にして、熱媒４を熱交換器２６側に循環させる。この結果、熱媒４は、貯湯タンク３４から流出した第２の熱媒である温水３２の熱を熱交換器２４を通して吸収する。
【００６３】
そして、温水３２から熱を吸収した熱媒４が熱交換器２６に循環し、温水９８が熱媒４から熱を吸収する。この温水９８が各暖房端末に循環し、暖房が行われる。この場合、貯湯タンク３４側の蓄熱量が低下し、暖房負荷が大きくなると、熱量が不足するので、暖房バックアップのため、バーナ１２０の燃焼を行うバックアップ制御を行う。
【００６４】
また、暖房回路の凍結防止として、貯湯タンク３４に蓄熱がある場合には、暖房バックアップを燃焼させることなく、貯湯タンク３４の温水３２→熱媒４→温水９８への熱伝達により、貯湯タンク３４の蓄熱を無駄なく消費して暖房回路及び暖房用温水器１２９の凍結防止を図ることができる。この場合も、貯湯タンク３４の蓄熱量が低下したときには、暖房バックアップの燃焼に切り換える。
【００６５】
このような貯湯タンク３４の蓄熱量を効率よく利用することで、エンジン２の運転による排熱の有効利用を図ることができる。
【００６６】
【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 熱源の排熱を吸収させた第１の熱媒から第２の熱媒に熱伝達を行い、蓄熱手段に第２の熱媒を以て蓄熱を行い、熱源の停止時、蓄熱手段の蓄熱を第１の熱媒を通じて第３の熱媒を加熱し、暖房に利用するので、適当な蓄熱量がある場合に暖房や凍結防止のために過剰な熱源の運転を回避でき、エンジン等の熱源の耐久性を高め、ランニングコストの低減とともに、蓄熱の有効利用を図ることができる。
ｂ 積層沸き上げを行う蓄熱手段を用いたので、蓄熱の有効利用を図ることができる。
ｃ 蓄熱手段の蓄熱を暖房回路の凍結防止に利用でき、エンジン等の熱源の耐久性を高め、ランニングコストの低減とともに、蓄熱の有効利用を図ることができる。
ｄ 直流ポンプを用いることで、低消費電力で幅の広い流量制御を実現することができる。
ｅ 熱源に跨がるバイパス路を第１の熱媒循環手段に形成し、第２の熱媒の熱を暖房に使用するとき、バイパス路を通して第１の熱媒を循環させるので、熱源の放熱損失を抑制でき、暖房時の蓄熱の利用効率を高めることができる。
【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】本発明の排熱回収制御のメインルーチン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】貯湯タンク残熱を利用した暖房制御を示すフローチャートである。
【図１６】暖房凍結予防動作制御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 第１の熱媒
６ 排熱回収路（第１の熱媒循環手段）
１２ バイパス路
１６ 循環ポンプ（第１の熱媒循環手段）
２４ 第１の熱交換器
２６ 第２の熱交換器
３２ 温水（第２の熱媒）
３４ 貯湯タンク（蓄熱手段）
３６ 循環路（第２の熱媒循環手段）
９８ 温水（第３の熱媒）
１００ 暖房用循環路（暖房回路）
１０２ 室内放熱器（暖房端末）
１０４ 浴室暖房乾燥機（暖房端末）
１０８ 循環ポンプ
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 is recovered through a cooling medium and 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, in the conventional exhaust heat utilization system, the operation control of the engine which is a drive source is performed based on the temperature detection of the hot water stored in the hot water storage tank, but a simple control for setting the heat storage amount or the operation time in advance is used. However, depending on the driving mode, there is a drawback that the running cost becomes high, such as decreasing the durability of the engine and increasing the heat dissipation loss.
[0004]
Then, this invention makes it a subject to provide the exhaust-heat-recovery control apparatus which aimed at the effective use of heat storage and reduced the running cost while improving the durability of a heat source.
[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, and first heat medium circulation means (exhaust heat recovery path 6, circulation) that circulates the first heat medium (4) to the heat source. The heat of the first heat medium that is circulated to the heat source by the pump 16) and the first heat medium circulation means and absorbs the exhaust heat from the heat source is supplied to the second heat medium (warm water 32). The first heat exchanger (24) to be absorbed, the heat storage means (hot water storage tank 34) for storing the second heat medium obtained by the first heat exchanger, and the first heat exchanger stored in the heat storage means Second heat medium circulating means (circulation path 36) for circulating the second heat medium to the first heat exchanger, and third heat to be circulated to the heating terminal (indoor radiator 102, bathroom heating dryer 104). medium second heat exchanger for heating (hot water 98) in the first heat medium (26), form the first heat medium circulation means A first bypass path (12) for circulating the first heat medium across the heat source, and the first heat medium circulation means separately from the first bypass path, A second bypass path (28) for shortening the circulation path of the first heat medium to be circulated to the heat source, and the first heat medium through the second bypass path during start-up operation or warm-up operation of the heat source. was circulated in the first heat medium circulation means, wherein the said the heating terminal of the heating requirement in the case that stop the operation of the heat source, the second of said heat first with the heating medium of the heat storage unit The first heat medium absorbed through the first heat exchanger is circulated through the first bypass passage to the first heat medium circulating means, and the heat quantity of the first heat medium is absorbed through the second heat exchanger. The control means (control part 12) which circulates the made said 3rd heat carrier to the said heating terminal Characterized by comprising a) a.
[0006]
That is, the first heat medium is a cooling medium for cooling a heat source such as an engine, and hot water, antifreeze liquid, or the like can be used, and is circulated to the heat source through the first heat medium circulation means. The second heat medium is a medium that absorbs the heat of the first heat medium, and warm water or the like is used and is circulated to the second heat medium circulation means. Moreover, the 3rd heat medium uses the warm water etc. which are circulated to a heating terminal. During start-up operation or warm-up operation of the heat source, the first heat medium is circulated to the heat source through the shortened circulation path of the first heat medium circulation means.
[0007]
Usually, the second heat medium is heated through the first heat exchanger by the first heat medium that has absorbed the exhaust heat of the heat source, and heat is stored in the heat storage means, and the third heat medium is passed through the second heat exchanger. The heating medium is heated, and heating is performed by circulating the third heating medium to the heating terminal.
[0008]
Therefore, when the operation of the heat source is stopped, the second heat medium is caused to flow from the heat storage means to the first heat exchanger so that the heat of the second heat medium is absorbed by the first heat medium, and the first heat medium. The amount of heat of the heat is absorbed by the third heat medium through the second heat exchanger, and the third heat medium is circulated to the heating terminal, whereby the heat stored in the heat storage means is used for heating. In this case, the first heat medium is a bearer of heat transfer between the second heat medium and the third heat medium.
[0009]
In the exhaust heat recovery control device of the present invention, the heat storage means is a hot water storage tank that stores the second heat medium before heating on the lower layer side and the second heat medium heated on the upper layer side. And In other words, stacked boiling of warm water is performed.
[0010]
In the exhaust heat recovery control apparatus of the present invention, a heating circuit (heating circulation path 100) that circulates the third heat medium in the heating terminal, and a pump that is provided in the heating circuit and circulates the third heat medium. (Circulation pump 108) and when the operation of the heat source is stopped, the heat of the second heat medium of the heat storage means is absorbed by the first heat medium through the first heat exchanger. Control means for circulating the third heat medium that has absorbed the heat quantity of the heat medium through the second heat exchanger to the heating circuit by the pump. That is, since the heat storage of the heat storage means is used to heat the third heat medium that circulates to the heating circuit side through the first heat medium, the heating circuit can be prevented from freezing.
[0011]
In the exhaust heat recovery control apparatus of the present invention, the pump is driven by a DC motor. That is, a pump driven by a direct current motor has low power consumption and can control a wide flow rate from a small flow rate to a large flow rate.
[0012]
In the exhaust heat recovery control apparatus of the present invention, the first bypass passage is connected to the first heat medium circulating means via a valve (three-way valve 14) controlled by the control means. And That is, since the first heat medium is circulated through the bypass path formed across the heat source, heat dissipation loss on the heat source side can be prevented.
[0013]
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.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to examples shown in the drawings.
[0015]
1 and 2 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.
[0016]
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 is formed as a first heat medium circulating means for circulating the first heat medium 4 as recovered water and recovering the exhaust heat of the engine 2 by the heat medium 4. 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.
[0017]
The heat exchanger 24 is a heating means for hot water 32 that is a second heat medium using the heat medium 4 as a heat source, and is a second heat medium circulation means for circulating water to be heated in a hot water storage tank 34 that is a heat storage means. Is provided in the circulation path 36. 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.
[0018]
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.
[0019]
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.
[0020]
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.
[0021]
The heat exchanger 26 provided in the exhaust heat recovery path 6 is a heating means for heating water that uses the heat medium 4 as a heat source and warm water 98 that is a third heat medium, and is a heating circuit as a heating circuit. It is provided on the road 100. This 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. Circulation pump 108, flow rate sensor 110, heat exchangers 96 and 112, and thermal valves 113 and 115 are provided on the heating terminal side. 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. Further, in the heat exchanger 96, the heat of the hot water 98 supplied from the hot water tank 106 side is used for heating the remedy circuit 84 side.
[0022]
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. .
[0023]
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, the control unit 124 receives detection outputs from various sensors such as the temperature sensor 127 for preventing freezing, the temperature sensors 8, 10 and the flow rate sensor 22 as control inputs. Is output to actuators of various control devices such as the DC motors 17 and 47 and the three-way valves 42 and 44. 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. The temperature sensor 127 is installed in the heating water heater 129 or outdoors. 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.
[0024]
Next, the exhaust heat recovery control will be described with reference to the main routine shown in FIG.
[0025]
When the power is turned on, in step S1, various positions such as the three-way valves 14, 30, 42, and 44 are subjected to initial position control (FIG. 6), and then the process proceeds to step S2. In step S2, a constant activation program is executed. In this always-start program, engine abnormal stop control (FIG. 7), engine operation permission control (FIG. 8), engine stop control (FIG. 9), engine forced stop control (FIG. 10), heating command control (FIG. 11), hot water supply Control of the integrated output counter 125 (FIG. 12), valve abnormality check control (FIG. 13), temperature sensor abnormality check control (FIG. 14), etc. are performed. In step S3, it is determined whether or not a heating command has been given to the control unit 124 (ON). If there is no heating command, the process proceeds to step S4 to determine whether or not engine operation is permitted. . That is, in step S4, it is confirmed whether or not it is within the operation permission time set according to the season.
[0026]
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,
[0027]
(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.
[0028]
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.
[0029]
[Table 1]

[0030]
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.
[0031]
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.
[0032]
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
[0033]
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
[0034]
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.
[0035]
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.
[0036]
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.
[0037]
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.
[0038]
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.
[0039]
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 whether 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.
[0040]
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.
[0041]
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.
[0042]
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.
[0043]
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”.
[0044]
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.
[0045]
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
[0046]
Qc = (hot water temperature-water temperature) × 1 (kcal) (4)
Is calculated by
[0047]
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.
[0048]
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.
[0049]
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.
[0050]
Next, FIG. 15 shows the heating control using the residual heat of the hot water storage tank 34.
[0051]
This heating control is executed by interrupt control for the main routine. When this control is started, it is determined in step S11 whether or not there is a heating request. If there is no heating request, the main routine shown in FIG. If there is a heating request, the process proceeds to step S12. In step S12, it is determined whether or not the engine 2 is in operation. When the engine 2 is in operation, the routine proceeds to a normal heating sequence. When the engine 2 is not in operation, the routine proceeds to step S13, where it is determined whether or not the residual heat in the hot water storage tank 34 exceeds a predetermined amount of heat, for example, 2000 kcal. When the process proceeds to the heating sequence and exceeds the predetermined heat quantity, the process proceeds to step S14. In step S14, it is determined whether or not the detected temperature of the temperature sensor 641 of the hot water storage tank 34 exceeds a predetermined temperature, for example, whether or not it exceeds 65 ° C. If not, the routine proceeds to a normal heating sequence. If it exceeds the predetermined temperature, the process proceeds to step S15.
[0052]
In step S15, switching of the three-way valves 14, 42, 44, operation of the circulation pumps 16, 45, operation of the circulation pump 108 on the heating side, heating valves on the heating terminal side such as the indoor radiator 102, the bathroom heating dryer 104, etc. 113 and 115 are opened. After such processing, in step S16, it is determined whether or not the detected temperature of the temperature sensor 641 of the hot water storage tank 34 exceeds a predetermined temperature, for example, 60 ° C., and if not, the normal heating sequence is performed. If the predetermined temperature is exceeded, the process proceeds to step S17.
[0053]
In step S17, it is determined whether or not there is a heating request. If there is no heating request, the process returns to the main routine of FIG. 4, and if there is a heating request, the process returns to step S16 to perform the process of step S16. . That is, when the residual heat amount of the hot water storage tank 34 exceeds a predetermined heat amount, that is, while the detected temperature of the temperature sensor 641 exceeds a predetermined temperature, for example, 60 ° C., the hot water storage tank 34 is subject to a heating request. The hot water is supplied to the heating terminal by heating using the heat of the hot water 32.
[0054]
Next, FIG. 16 shows the heating freeze prevention operation control.
[0055]
This heating / freezing prevention operation is executed by interrupt control for the main routine, and when this control is started, in step S21, whether or not the temperature sensor 127 is below a predetermined temperature at which freezing is expected, for example, 6 ° C. or less. If the temperature is not lower than the predetermined temperature, the process proceeds to step S22. The normal operation is continued. If the temperature is lower than the predetermined temperature, the process proceeds to step S23. In step S23, the circulation pump 108 for heating is operated and the thermal valves 113 and 115 of the circulation circuit 100 for heating are opened, and then the process proceeds to step S24.
[0056]
In step S24, it is determined whether or not the exhaust heat recovery operation is being performed. If the operation is being performed, the process proceeds to step S25, whether or not the temperature detected by the temperature sensor 127 for preventing freezing is equal to or higher than a predetermined temperature, For example, it is determined whether or not the temperature is 10 ° C. or higher. If the temperature is not equal to or higher than the predetermined temperature, the process returns to step S24. If the temperature is higher than the predetermined temperature, the process proceeds to step S26. . That is, after a predetermined time, the process proceeds to step S27, the circulation pump 108 is stopped, the thermal valves 113 and 115 are closed, and the freeze prevention operation is ended. That is, during the exhaust heat recovery operation, the amount of heat obtained by the exhaust heat recovery is used for freezing prevention.
[0057]
If the exhaust heat recovery operation is not being performed in step S24, the process proceeds to step S28, where it is determined whether or not the hot water storage tank 34 has a heat storage amount necessary for freezing prevention. In step S29, as control for using the hot water 32 in the hot water storage tank 34, the three-way valves 14, 42, 44 are switched, the circulation pump 16 and the circulation pump 45 are switched to the operating state, and the process proceeds to step S30.
[0058]
In step S30, it is determined whether or not the temperature detected by the temperature sensor 127 is equal to or higher than a predetermined temperature, for example, 15 ° C. or higher. If the temperature is equal to or higher than the predetermined temperature, the process proceeds to step S31. Wait for minutes. That is, after a predetermined time, the process proceeds to step S32, the heating circulation pump 108 and the circulation pumps 16 and 45 are stopped, the thermal valves 113 and 115 are closed, and the freeze prevention operation is ended. That is, when the exhaust heat recovery operation is not being performed, when the heat storage amount necessary for preventing freezing exists in the hot water storage tank 34, the heat amount is used for freezing prevention.
[0059]
However, if the heat storage amount necessary for the hot water storage tank 34 does not exist in step S28, it is necessary to secure the heat amount necessary for preventing freezing. Therefore, in step S33, the burner 120 is burned as backup combustion, the process proceeds to step S34, and it is determined whether the temperature detected by the temperature sensor 127 is equal to or higher than a predetermined temperature, for example, 20 ° C. or higher. If it is not equal to or higher than the predetermined temperature, the process returns to step S28. If it is equal to or higher than the predetermined temperature, the process proceeds to step S35, the combustion of the burner 120 as the backup combustion is stopped, and the process proceeds to step S36 as a predetermined time. Wait for 16 minutes. That is, after a predetermined time, the process proceeds to step S37, the heating circulation pump 108 is stopped, the thermal valves 113 and 115 are closed, and the freeze prevention operation is ended. That is, when the exhaust heat recovery operation is not being performed and the heat storage amount necessary for preventing freezing does not exist in the hot water storage tank 34, the burner 120 is burned and the heat amount is used for freezing prevention.
[0060]
As described above, when there is a heating request, the engine 2 is operated to perform heating. However, when there is a necessary heat storage amount in the hot water storage tank 34, the engine 2 is not operated, that is, the engine 2 is operated. In the hot water storage tank 34, the heat medium 4 is heated through the heat exchanger 24 using the heat stored in the hot water storage tank 34 as the heat source. The heating medium 4 is circulated to the heat exchanger 26 through the exhaust heat recovery path 6 that is an engine cooling circuit, and the hot water 98 that is the third heating medium is heated to perform the heating operation. That is, the heat stored in the hot water storage tank 34 is used for heating. Similarly, it can be used as a heat source for preventing freezing of the heating circulation path 100 and the heating water heater 129.
[0061]
Specifically, when such a process is requested from the heating terminal side such as the indoor radiator 102 or the bathroom heating dryer 104, the direction of the three-way valves 42 and 44 on the input / output side of the heat exchanger 24 is changed. Then, the circulation pump 45 is operated to take out hot hot water 32 from the upper side of the hot water storage tank 34 and flow it through the heat exchanger 24 to the lower side of the hot water storage tank 34.
[0062]
At the same time, the direction of the three-way valve 14 is changed, the circulation pump 16 is operated, and the exhaust heat recovery path 6 on the engine 2 side is short-circuited by the bypass path 12 so that the heat medium 4 does not circulate to the engine 2 side. The medium 4 is circulated to the heat exchanger 26 side. As a result, the heat medium 4 absorbs the heat of the hot water 32 that is the second heat medium flowing out from the hot water storage tank 34 through the heat exchanger 24.
[0063]
Then, the heat medium 4 that has absorbed heat from the hot water 32 circulates in the heat exchanger 26, and the hot water 98 absorbs heat from the heat medium 4. This hot water 98 circulates to each heating terminal, and heating is performed. In this case, when the amount of stored heat on the hot water storage tank 34 side decreases and the heating load increases, the amount of heat becomes insufficient. Therefore, backup control for burning the burner 120 is performed for heating backup.
[0064]
Further, in order to prevent freezing of the heating circuit, when there is heat storage in the hot water storage tank 34, the hot water storage tank 34 is transferred by heat transfer from the hot water 32 to the hot medium 4 to the hot water 98 in the hot water storage tank 34 without burning the heating backup. It is possible to prevent the freezing of the heating circuit and the heating water heater 129 by consuming the heat storage without waste. Also in this case, when the amount of heat stored in the hot water storage tank 34 is reduced, the combustion is switched to heating backup.
[0065]
By efficiently using the amount of heat stored in the hot water storage tank 34, it is possible to effectively use the exhaust heat from the operation of the engine 2.
[0066]
【The invention's effect】
As described above, according to the present invention, the following effects can be obtained.
a Heat transfer from the first heat medium that has absorbed the exhaust heat of the heat source to the second heat medium, heat storage using the second heat medium to the heat storage means, and when the heat source is stopped, Since the third heat medium is heated through the heat medium of 1 and used for heating, operation of an excessive heat source can be avoided to prevent heating and freezing when there is an appropriate amount of heat storage, and durability of the heat source such as the engine The efficiency can be improved, the running cost can be reduced, and the effective use of heat storage can be achieved.
b Since the heat storage means for carrying out stacking and boiling is used, effective use of the heat storage can be achieved.
c The heat storage of the heat storage means can be used to prevent the freezing of the heating circuit, the durability of the heat source such as the engine can be improved, the running cost can be reduced, and the heat storage can be used effectively.
d By using the direct current pump, wide flow control with low power consumption can be realized.
e When a bypass path over the heat source is formed in the first heat medium circulation means and the heat of the second heat medium is used for heating, the first heat medium is circulated through the bypass path. Loss can be suppressed and the utilization efficiency of the heat storage at the time of heating can be improved.
[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 a main routine of exhaust heat recovery control of the present invention.
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 heating control using hot water storage tank residual heat.
FIG. 16 is a flowchart showing heating freeze prevention operation control.
[Explanation of symbols]
2 Engine (heat source)
4 First heat medium 6 Waste heat recovery path (first heat medium circulation means)
12 Bypass path 16 Circulation pump (first heat medium circulation means)
24 1st heat exchanger 26 2nd heat exchanger 32 Hot water (2nd heat medium)
34 Hot water storage tank (heat storage means)
36 Circulation path (second heat medium circulation means)
98 Hot water (third heat medium)
100 Heating circuit (heating circuit)
102 Indoor radiator (heating terminal)
104 Bathroom heating dryer (heating terminal)
108 Circulating pump 124 Control unit (control means)

Claims (6)

A heat source that releases heat,
A first heat medium circulating means for circulating the first heat medium to the heat source;
A first heat exchanger that circulates to the heat source by the first heat medium circulating means and absorbs the heat of the first heat medium that has absorbed exhaust heat from the heat source to the second heat medium; ,
Heat storage means for storing the second heat medium obtained by the first heat exchanger;
Second heat medium circulating means for circulating the second heat medium stored in the heat storage means to the first heat exchanger;
A second heat exchanger for heating a third heat medium to be circulated to the heating terminal with the first heat medium;
A first bypass path formed in the first heat medium circulating means and circulating the first heat medium across the heat source;
A second bypass path that is formed in the first heat medium circulation means separately from the first bypass path and shortens the circulation path of the first heat medium to be circulated to the heat source,
During the start-up operation or warm-up operation of the heat source, the heating in the case where the first heat medium is circulated to the first heat medium circulation means through the second bypass path and the operation of the heat source is stopped. At the time of the heating request on the terminal side, the first heat medium in which the heat of the second heat medium of the heat storage means is absorbed through the first heat exchanger passes through the first bypass path and the first heat medium. Control means for circulating to the heating terminal the third heat medium which is circulated through the medium circulation means and has absorbed the amount of heat of the first heat medium through the second heat exchanger;
An exhaust heat recovery control device comprising:   The exhaust heat recovery according to claim 1, wherein the heat storage means is a hot water storage tank that stores the second heating medium before heating on the lower layer side and the second heating medium heated on the upper layer side. Control device. A heating circuit for circulating the heating medium of 3 in the heating terminal;
A pump provided in the heating circuit for circulating the third heat medium;
When the operation of the heat source is stopped, the heat of the second heat medium of the heat storage means is absorbed by the first heat medium through the first heat exchanger, and the amount of heat of the first heat medium is Control means for circulating the third heat medium absorbed through the heat exchanger of 2 to the heating circuit by the pump;
The exhaust heat recovery control device according to claim 1, comprising:   The exhaust heat recovery control device according to claim 1, wherein the pump is driven by a DC motor. 4. The exhaust heat recovery control device according to claim 1, wherein the first bypass passage is connected to the first heat medium circulation means via a valve controlled by the control means . 5.   6. The exhaust heat recovery control device according to claim 1, wherein a driving source for rotating a generator is used as the heat source.

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