JP4570292B2

JP4570292B2 - Air conditioner

Info

Publication number: JP4570292B2
Application number: JP2001249248A
Authority: JP
Inventors: 武横山; 卓中村; 浩鶴岡; 優相見; 祐成舘; 廣秋岸; 英一河合; 立二森島; 光正福村; 秀晃笠原; 彰中島
Original assignee: Osaka Gas Co Ltd; Tokyo Gas Co Ltd; Toho Gas Co Ltd
Current assignee: Osaka Gas Co Ltd; Tokyo Gas Co Ltd; Toho Gas Co Ltd
Priority date: 2001-08-20
Filing date: 2001-08-20
Publication date: 2010-10-27
Anticipated expiration: 2021-08-20
Also published as: JP2003056932A

Description

【０００１】
【発明の属する技術分野】
本発明は空気調和装置に関し、特に圧縮機を駆動する駆動手段の排熱を利用して冷媒の加熱を行う構造を有するヒートポンプ式の空気調和装置に関する。
【０００２】
【従来の技術】
圧縮機の駆動手段にガスエンジン等の内燃機関を採用し、さらにこの内燃機関の排熱を利用して冷媒の加熱を行う構造を有するヒートポンプ式の空気調和装置がある。この空気調和装置においては、圧縮機に求められる負荷が小さければ回転数を低くし、大きければ回転数を高くするといった具合に、負荷に応じてエンジンの回転数を変化させるようになっている。そのため、エンジンには広い回転数域を備えることが求められる。
【０００３】
しかしながら、ガスエンジン等の内燃機関は高効率運転の可能な回転数域が限られている。そこで従来の空気調和装置においては、通常運転の際に頻繁に求められる負荷の範囲に対応する回転数域で高効率運転が可能なようにエンジンの調整がなされている。
【０００４】
【発明が解決しようとする課題】
従来の空気調和装置では、上記のような調整を行うため、一般的な範囲を外れた大きさの負荷が求められた場合には、エンジンに効率の悪い運転を行わせることになる。そのため、燃費が悪化する等して運転コストが増加するといった問題点が指摘されている。
【０００５】
特開平11-132594号公報には、容量の大きな圧縮機を電動モータまたはエンジンのいずれか一方で選択的に駆動させ、負荷が小さい場合は電動モータで圧縮機を駆動し、負荷が大きい場合はエンジンで圧縮機を駆動させてエンジンに効率の悪い運転をさせない技術について開示されている。
【０００６】
しかしながら、上記公報に開示された技術では、例えば求められる負荷が小さい場合、容量の大きな圧縮機を低速で駆動させるので十分な圧縮効率が得られない。容量の大きな圧縮機を低速で駆動すると、中高速で駆動する場合と比較して被圧縮流体の漏洩が多くなるからである。
【０００７】
また、上記公報に開示された技術では、本来非力な電動モータで内部摩擦の大きな圧縮機を駆動させることで電動モータに無理を強いることになり、結果的に見て装置全体としては高い運転効率が得られているとは言い難い。
【０００８】
本発明は上記の事情に鑑みてなされたものであり、求められる負荷の大きさに関わらず高効率運転が可能な空気調和装置を提供することを目的としている。
【０００９】
【課題を解決するための手段】
上記の課題を解決するための手段として、次のような構成の空気調和装置を採用する。
すなわち請求項１記載の空気調和装置は、室内熱交換器、室外熱交換器、膨張弁および四方弁を冷媒管路を介して接続するとともに該冷媒管路に容量の異なる２つの圧縮機を並列に接続し、該２つの圧縮機に個々に駆動手段を設け、前記２つの圧縮機のうち少なくとも容量の大きな圧縮機を駆動する駆動手段に内燃機関を採用した空気調和装置であって、
暖房運転時に中温中圧の液冷媒を導通することとなる中圧冷媒管路に一端を接続され、前記２つの圧縮機のうち容量の小さな圧縮機の上流側に位置する一方の冷媒管路に他端を接続された第１のバイパス管路を設け、
該第１のバイパス管路には、暖房運転時に必要に応じて開閉して前記第１のバイパス管路への冷媒の導入を制限する第１の開閉弁と、前記内燃機関の排熱を利用して低温低圧の液冷媒を加熱、気化させる第１の排熱利用熱交換器とを前記中圧冷媒管路側から順に並べて設け、
前記第１のバイパス管路との接続箇所より上流側に位置する前記一方の冷媒管路には、必要に応じて開閉して前記容量の小さな圧縮機への冷媒の導入を制限する第２の開閉弁を設け、
前記第１のバイパス管路との接続箇所より暖房運転時の上流側に位置する前記中圧冷媒管路に一端を接続され、前記２つの圧縮機のうち容量の大きな圧縮機の上流側に位置する他方の冷媒管路に他端を接続された第２のバイパス管路を設け、
該第２のバイパス管路には、暖房運転時に必要に応じて開閉して前記第２のバイパス管路への冷媒の導入を制限する第３の開閉弁と、中温中圧の液冷媒を低温低圧の液冷媒に減圧する減圧弁と、前記内燃機関の排熱を利用して低温低圧の液冷媒を加熱、気化させる第２の排熱利用熱交換器とを前記中圧冷媒管路側から順に並べて設け、
前記第１のバイパス管路との接続箇所より暖房運転時の下流側に位置する前記中圧冷媒管路には、必要に応じて開閉して前記室外熱交換器への冷媒の導入を制限する第４の開閉弁を設けたことを特徴とする。
【００１０】
請求項２記載の空気調和装置は、請求項１記載の空気調和装置において、前記２つの圧縮機のうち少なくとも容量の大きな圧縮機を駆動する駆動手段にガスエンジンを採用したことを特徴とする。
【００１１】
請求項３記載の空気調和装置は、請求項１または２記載の空気調和装置において、前記２つ圧縮機のうち容量の小さなものを駆動する駆動手段に電動モータを採用したことを特徴とする。
【００１２】
請求項４記載の空気調和装置は、請求項１記載の空気調和装置において、前記２つの圧縮機に個々に設けた駆動手段の少なくともいずれか一方を電動モータとし、該電動モータを駆動する発電装置を併設し、該発電装置の排熱を暖房運転時の冷媒加熱に利用することを特徴とする。
【００１３】
請求項５記載の空気調和装置は、請求項１、２、３または４記載の空気調和装置において、前記暖房運転時に、前記第１、第３の開閉弁を閉じ前記第２、第４の開閉弁を開いて前記２つの圧縮機のうち容量の小さいもののみを駆動させるか、前記第１、第２の開閉弁を閉じ前記第３、第４の開閉弁を開いて前記２つの圧縮機のうち容量の大きなもののみを駆動させるか、または前記第１、第４の開閉弁を開き前記第２、第３の開閉弁を閉じて前記２つの圧縮機を同時に駆動させるかいずれかの運転を、求められる負荷に応じて選択的に実行することを特徴とする。
【００１４】
請求項６記載の空気調和装置は、請求項１、２、３、４または５記載の空気調和装置において、前記第１、第２、第４の開閉弁を閉じ前記第３の開閉弁を開いて前記２つの圧縮機のうち容量の大きなもののみを駆動させる運転を、求められる負荷および屋外の気温に応じて実行することを特徴とする。
【００１５】
請求項７記載の空気調和装置は、請求項１、２、３、４、５または６記載の空気調和装置において、冷房運転時に、前記第１、第３の開閉弁を閉じ前記第２、第４の開閉弁を開いて前記２つの圧縮機のうち容量の小さいもののみを駆動させるか、前記第１、第２、第３の開閉弁を閉じ前記第４の開閉弁を開いて前記２つの圧縮機のうち容量の大きなもののみを駆動させるか、または前記第１、第３の開閉弁を閉じ前記第２、第４の開閉弁を開いて前記２つの圧縮機を同時に駆動させるかいずれかの運転を、求められる負荷に応じて選択的に実行することを特徴とする。
【００１６】
【発明の実施の形態】
本発明に係る実施形態を図１および図２に示して説明する。
図１には、容量の異なる２つの圧縮機をガスエンジンと電動モータとで個々に駆動する構造を有するヒートポンプ式の空気調和装置を示す。この空気調和装置は、室外ユニット１０と室内ユニット２０とから構成されており、これらは冷媒を導通する冷媒配管３０や図示しない電気配線等によって接続されている。
【００１７】
室外ユニット１０には、屋外の空気と冷媒との間で熱交換を行う室外熱交換器１１と、室外熱交換器１１または後述する室内熱交換器２１に冷媒を送出する２つの圧縮機１２Ａ，１２Ｂと、冷媒配管３０を流通する冷媒の流れ方向を切り替える四方弁１３と、暖房運転時に使用される膨張弁１４と、冷媒を気液分離するレシーバ１５と、室外熱交換器１１に屋外の空気を流通させる室外ファン１６とが具備され、冷媒配管３０を介して接続されて冷媒循環系の一部を構成している。
【００１８】
２つの圧縮機１２Ａ，１２Ｂは容量が異なり、室外ユニット１０において上記各機器と冷媒配管３０からなる冷媒循環系に並列に接続されている。圧縮機１２Ａ，１２Ｂのうち、容量の大きな圧縮機１２Ａの駆動手段にはガスエンジン（内燃機関）ＥＧが採用され、容量の小さな圧縮機１２Ｂの駆動手段には電動モータＭが採用されている。
【００１９】
ガスエンジンＥＧは、中程度の負荷に対応して圧縮機１２Ａの能力を活かして（すなわち圧縮機１２Ａの容量に見合った回転数域で）駆動させたときに燃費の良い高効率運転が行えるように調整されている。電動モータＭは、小さい負荷に対応して圧縮機１２Ｂの能力を活かして（すなわち圧縮機１２Ｂの容量に見合った回転数域で）駆動させたときに無理のない運転が行えるように適切な出力が得られるものが選択されている。
【００２０】
圧縮機１２Ａ，１２Ｂの上流側には個々にアキュムレータ１７Ａ，１７Ｂがそれぞれ設けられ、下流側にはオイルセパレータ１８Ａ，１８Ｂおよび各圧縮機への冷媒の逆流を阻止する逆止弁Ｖ１がそれぞれ設けられている。オイルセパレータ１８Ａ，１８Ｂには、ガス冷媒から分離した油分を圧縮機１２Ａ，１２Ｂの上流側に戻す油戻し管１９がそれぞれ設けられている。
【００２１】
膨張弁１４の前後の冷媒配管３０には、膨張弁１４をバイパスするバイパス配管３１が設けられ、バイパス管路３１には暖房運転時にバイパス配管３１への冷媒の流入を阻止する逆止弁Ｖ２が設けられている。
【００２２】
室内ユニット２０には、屋内の空気と冷媒との間で熱交換を行う室内熱交換器２１と、冷房運転時に使用される電磁膨張弁２２と、室内熱交換器２１に室内の空気を流通させる室内ファン２３とが具備され、冷媒配管３０を介して接続されて室外ユニット１０とともに冷媒循環系を構成している。
【００２３】
電磁膨張弁２２の前後の冷媒配管３０には、電磁膨張弁２２をバイパスするバイパス配管３２が設けられ、バイパス配管３２には冷房運転時にバイパス配管３２への冷媒の流入を阻止する逆止弁Ｖ３が設けられている。
【００２４】
また、上記室外ユニット１０には、室外熱交換器１１と室内熱交換器２１とに連通し暖房運転時に中温中圧の液冷媒（すなわち凝縮器である室内熱交換器２１を通過した後の液冷媒）を導通することとなる冷媒配管（中圧冷媒管路）３０ａに一端を接続され、容量の小さな圧縮機１２Ｂの上流側に位置する分岐冷媒配管（一方の冷媒管路）３０ｂに他端を接続されたバイパス配管（第１のバイパス管路）３３が設けられている。
【００２５】
バイパス配管３３には、必要に応じて開閉してバイパス配管３３への液冷媒の導入を制限する開閉弁（第１の開閉弁）Ｖ４、ガスエンジンＥＧの排熱を利用して低温低圧の液冷媒を加熱、気化させる排熱利用熱交換器（第１の排熱利用熱交換器）４０が、冷媒配管３０ａ側から順に並んで設けられている。
【００２６】
また、分岐冷媒配管３０ｂには、必要に応じて開閉して圧縮機１２Ｂへの冷媒の導入を制限する開閉弁（第２の開閉弁）Ｖ５が設けられている。
【００２７】
上記室外ユニット１０には、バイパス配管３３との接続箇所より暖房運転時の上流側に位置する冷媒配管３０ａに一端を接続され、容量の大きな圧縮機１２Ａの上流側に位置する分岐冷媒配管（他方の冷媒管路）３０ｃに他端を接続されたバイパス配管（第２のバイパス管路）３４が設けられている。
【００２８】
バイパス配管３４には、必要に応じて開閉してバイパス配管３４への冷媒の導入を制限する開閉弁（第３の開閉弁）Ｖ６、中温中圧の液冷媒を低温低圧の液冷媒に減圧する膨張弁（減圧弁）３５、ガスエンジンＥＧの排熱を利用して低温低圧の液冷媒を加熱、気化させる排熱利用熱交換器（第２の排熱利用熱交換器）４１が、冷媒配管３０ａ側から順に並んで設けられている。
【００２９】
さらに、上記室外ユニット１０には、バイパス配管３３との接続箇所より暖房運転時の下流側に位置する冷媒配管３０ａに、必要に応じて開閉して室外熱交換器１１への冷媒の導入を制限する開閉弁（第４の開閉弁）Ｖ７が設けられている。
【００３０】
ガスエンジンＥＧと排熱利用熱交換器４０との間には、ガスエンジンＥＧの排熱を伝達し排熱利用熱交換器４０において冷媒と熱交換させる排熱伝達手段４２が設けられている。ガスエンジンＥＧと排熱利用熱交換器４１との間にも、同様の排熱伝達手段４３が設けられている。排熱伝達手段４２，４３は、例えばガスエンジンＥＧの排気を排熱利用熱交換器４０、４１に直接導くもの、ガスエンジンＥＧで加熱された冷却水を排熱利用熱交換器４０、４１に導いて間接的に熱を伝達するもの等である。
【００３１】
さらに、上記空気調和装置には、２つの圧縮機１２Ａ，１２Ｂに求められる負荷に応じて各圧縮機を個別に駆動させたり２つをともに駆動させたりする制御を行う制御部５０が設けられている。制御部５０では、圧縮機１２Ａ，１２Ｂの駆動を制御するとともに、冷房運転／暖房運転の切り換え時や求められる負荷の大きさに応じて四方弁１３や開閉弁Ｖ４，Ｖ５，Ｖ６，Ｖ７を切り換える制御を行うようになっている。
【００３２】
上記のように構成された空気調和装置の作動の仕方を冷房運転と暖房運転とに分け、さらにそれぞれの運転状態において求められる負荷の大きさごとに分けて説明する。
［冷房運転；低負荷時］
このモードでは、容量の小さな圧縮機１２Ｂのみが電動モータＭによって駆動される。開閉弁Ｖ４，Ｖ６は閉じられ、開閉弁Ｖ５，Ｖ７は開かれる。
冷媒は圧縮機１２Ｂで圧縮されて高温高圧のガス冷媒となり、オイルセパレータ１８Ｂ、四方弁１３を経て室外熱交換器１１に流入する。室外熱交換器１１では、高温高圧のガス冷媒が室外ファン１６によって取り込まれた屋外の空気に熱を与えて排熱し、自らは凝縮、液化して中温中圧の液冷媒となる。
【００３３】
この中温中圧の液冷媒は、膨張弁１４をバイパスし、レシーバ１５にて気液分離された後、冷媒配管３０を通じて室内ユニット２０に送出され、電磁膨張弁２２を通過する過程で減圧されて低温低圧の液冷媒となり、室内熱交換器２１に流入する。室内熱交換器２１では、低温低圧の液冷媒が室内ファン２３によって取り込まれた室内の空気から熱を奪って冷却し、自らは蒸発、気化して低温低圧のガス冷媒となる。この低温低圧のガス冷媒は、冷媒配管３０を通じて室外ユニット１０に送出され、四方弁１３、アキュムレータ１７Ｂを経て圧縮機１２Ｂに吸入、圧縮される。以降は上記過程を繰り返すこととなる。
【００３４】
［冷房運転；中負荷時］
このモードでは、容量の大きな圧縮機１２ＡのみがガスエンジンＥＧによって駆動される。開閉弁Ｖ４，Ｖ５，Ｖ６は閉じられ、開閉弁Ｖ７は開かれる。このモードでは圧縮機が容量の小さな１２Ｂから容量の大きな１２Ａに切り換えられるだけで、作動の仕方は低負荷時と同じである。なお、圧縮機の切り換えに伴い機能するオイルセパレータおよびアキュムレータもそれぞれに対応して設けられたものに切り換わる。
【００３５】
［冷房運転；高負荷時］
このモードでは、圧縮機１２Ａ，１２Ｂがそれぞれの駆動手段によって同時に駆動される。開閉弁Ｖ４，Ｖ６は閉じられ、開閉弁Ｖ５，Ｖ７は開かれる。このモードは２つの圧縮機１２Ａ，１２Ｂが同時に駆動するだけで、作動の仕方は低負荷時や中負荷時と同じである。
【００３６】
［暖房運転；低負荷時］
このモードでは、容量の小さな圧縮機１２Ｂのみが電動モータＭによって駆動される。開閉弁Ｖ４、Ｖ６は閉じられ、Ｖ５，Ｖ７は開かれる。
冷媒は圧縮機１２Ｂで圧縮されて高温高圧のガス冷媒となり、オイルセパレータ１８Ｂ、四方弁１３を経て室内ユニット２０に送出され、室内熱交換器２１に流入する。室内熱交換器２１では、高温高圧のガス冷媒が室内ファン２３によって取り込まれた室内の空気に熱を与えて加熱し、自らは凝縮、液化して中温中圧の液冷媒となる。
【００３７】
この中温中圧の液冷媒は、電磁膨張弁２２をバイパスし、冷媒配管３０を通じて室外ユニット１０に送出され、レシーバ１５にて気液分離された後、膨張弁１４を通過する過程で減圧されて低温低圧の液冷媒となり、室外熱交換器１１に流入する。室外熱交換器１１では、低温低圧の液冷媒が室外ファン１６によって取り込まれた屋外の空気から熱を奪い、自らは蒸発、気化して低温低圧のガス冷媒となる。この低温低圧のガス冷媒は、四方弁１３、アキュムレータ１７Ｂを経て圧縮機１２Ｂに吸入、圧縮される。以降は上記過程を繰り返すこととなる。
【００３８】
［暖房運転；中負荷時］
このモードでは、容量の大きな圧縮機１２ＡのみがガスエンジンＥＧによって駆動される。開閉弁Ｖ４，Ｖ５は閉じられ、開閉弁Ｖ６，Ｖ７は開かれる。
冷媒は圧縮機１２Ａで圧縮されて高温高圧のガス冷媒となり、オイルセパレータ１８Ａ、四方弁１３を経て室内ユニット２０に送出され、室内熱交換器２１に流入する。室内熱交換器２１では、高温高圧のガス冷媒が室内ファン２３によって取り込まれた室内の空気に熱を与えて加熱し、自らは凝縮、液化して中温中圧の液冷媒となる（ここまでは圧縮機が１２Ｂから１２Ａに切り換えられるだけで、作動の仕方は低負荷時と同じ）。
【００３９】
この中温中圧の液冷媒は、電磁膨張弁２２をバイパスし、冷媒配管３０を通じて室外ユニット１０に送出され、レシーバ１５にて気液分離された後、一部がバイパス配管３４に流入する。バイパス配管３４に流入しなかった残りの液冷媒は、膨張弁１４を通過する過程で減圧されて低温低圧の液冷媒となり、室外熱交換器１１に流入して屋外の空気から熱を奪い、自らは蒸発、気化して低温低圧のガス冷媒となる。
【００４０】
バイパス配管３４に流入した中温中圧の液冷媒は、膨張弁３５を通過する過程で減圧されて低温低圧の液冷媒となり、排熱利用熱交換器４１に流入する。排熱利用熱交換器４１では、低温低圧の液冷媒がガスエンジンＥＧから排熱伝達手段４３を介して伝達された排熱を利用して加熱され、蒸発、気化して低温低圧のガス冷媒となる。
【００４１】
室外熱交換器１１において蒸発、気化した低温低圧のガス冷媒と、排熱利用熱交換器４１において蒸発、気化した低温低圧のガス冷媒とはアキュムレータ１７Ａで合流し、圧縮機１２Ａに吸入される。以降は上記過程を繰り返すこととなる。
【００４２】
［暖房運転；高負荷時］
このモードでは、圧縮機１２Ａ，１２Ｂがそれぞれの駆動手段によって同時に駆動される。開閉弁Ｖ４，Ｖ５，Ｖ７は開かれ、開閉弁Ｖ６は閉じられる。
冷媒は圧縮機１２Ａ，１２Ｂから高温高圧のガス状態で吐出され、オイルセパレータ１８Ａ，１８Ｂを経て合流し、四方弁１３を経て室内ユニット２０に送出され、室内熱交換器２１に流入する。室内熱交換器２１では、高温高圧のガス冷媒が室内ファン２３によって取り込まれた室内の空気に熱を与えて加熱し、自らは凝縮、液化して中温中圧の液冷媒となる。
【００４３】
この中温中圧の液冷媒は、電磁膨張弁２２をバイパスし、冷媒配管３０を通じて室外ユニット１０に送出され、レシーバ１５にて気液分離された後、一部がバイパス配管３３に流入する。バイパス配管３３に流入しなかった残りの液冷媒は、膨張弁１４を通過する過程で減圧されて低温低圧の液冷媒となり、室外熱交換器１１に流入して屋外の空気から熱を奪い、自らは蒸発、気化して低温低圧のガス冷媒となる。
【００４４】
バイパス配管３３に流入した中温中圧の液冷媒は、排熱利用熱交換器４０に流入し、ガスエンジンＥＧから排熱伝達手段４２を介して伝達された排熱を利用して加熱され、蒸発、気化して中温中圧のガス冷媒となる。
【００４５】
室外熱交換器１１において蒸発、気化した低温低圧のガス冷媒は、アキュムレータ１７Ａを経て圧縮機１２Ａに吸入、圧縮される。排熱利用熱交換器４０において蒸発、気化した中温中圧のガス冷媒は、アキュムレータ１７Ｂを経て圧縮機１２Ｂに吸入される。この場合の圧縮機１２Ｂはガスポンプとして機能し、中温中圧のガス冷媒を高温高圧のガス冷媒として吐出する。以降は上記過程を繰り返すこととなる。
【００４６】
［暖房運転；低外気温，低負荷時］
このモードでは、容量の大きな圧縮機１２ＡのみがガスエンジンＥＧによって駆動される。開閉弁Ｖ４，Ｖ５，Ｖ７は閉じられ、開閉弁Ｖ６は開かれる。
冷媒は圧縮機１２Ａで圧縮されて高温高圧のガス冷媒となり、オイルセパレータ１８Ａ、四方弁１３を経て室内ユニット２０に送出され、室内熱交換器２１に流入する。室内熱交換器２１では、高温高圧のガス冷媒が室内ファン２３によって取り込まれた室内の空気に熱を与えて加熱し、自らは凝縮、液化して中温中圧の液冷媒となる。
【００４７】
この中温中圧の液冷媒は、電磁膨張弁２２をバイパスし、冷媒配管３０を通じて室外ユニット１０に送出され、レシーバ１５にて気液分離された後、バイパス配管３４に流入する。バイパス配管３４に流入した中温中圧の液冷媒は、膨張弁３５を通過する過程で減圧されて低温低圧の液冷媒となり、排熱利用熱交換器４１に流入する。排熱利用熱交換器４１では、低温低圧の液冷媒がガスエンジンＥＧから排熱伝達手段４３を介して伝達された排熱を利用して加熱され、蒸発、気化して低温低圧のガス冷媒となる。
【００４８】
排熱利用熱交換器４１において蒸発、気化した低温低圧のガス冷媒はアキュムレータ１７Ａを経て圧縮機１２Ａに吸入、圧縮される。以降は上記過程を繰り返すこととなる。
【００４９】
［暖房運転；低外気温，中／高負荷時］
このモードでは、圧縮機１２Ａ，１２Ｂがそれぞれの駆動手段によって同時に駆動される。開閉弁Ｖ４，Ｖ６は開かれ、開閉弁Ｖ５，Ｖ７は閉じられる。
冷媒は圧縮機１２Ａ，１２Ｂから高温高圧のガス状態で吐出され、オイルセパレータ１８Ａ，１８Ｂを経て合流し、四方弁１３を経て室内ユニット２０に送出され、室内熱交換器２１に流入する。室内熱交換器２１では、高温高圧のガス冷媒が室内ファン２３によって取り込まれた室内の空気に熱を与えて加熱し、自らは凝縮、液化して中温中圧の液冷媒となる。
【００５０】
この中温中圧の液冷媒は、電磁膨張弁２２をバイパスし、冷媒配管３０を通じて室外ユニット１０に送出され、レシーバ１５にて気液分離された後、一部がバイパス配管３３に流入し、残りがバイパス配管３４に流入する。バイパス配管３３に流入した中温中圧の液冷媒は、排熱利用熱交換器４０に流入し、ガスエンジンＥＧから排熱伝達手段４２を介して伝達された排熱を利用して加熱され、蒸発、気化して中温中圧のガス冷媒となる。
【００５１】
バイパス配管３４に流入した中温中圧の液冷媒は、膨張弁３５を通過する過程で減圧されて低温低圧の液冷媒となり、排熱利用熱交換器４１に流入する。排熱利用熱交換器４１では、低温低圧の液冷媒がガスエンジンＥＧから排熱伝達手段４３を介して伝達された排熱を利用して加熱され、蒸発、気化して低温低圧のガス冷媒となる。
【００５２】
排熱利用熱交換器４０において蒸発、気化した中温中圧のガス冷媒は、アキュムレータ１７Ｂを経て圧縮機１２Ｂに吸入される。この場合の圧縮機１２Ｂはガスポンプとして機能し、中温中圧のガス冷媒を高温高圧のガス冷媒として吐出する。排熱利用熱交換器４１において蒸発、気化した低温低圧のガス冷媒は、アキュムレータ１７Ａを経て圧縮機１２Ａに吸入、圧縮される。以降は上記過程を繰り返すこととなる。
【００５３】
上記のような作動をする空気調和装置においては、図２に示すように、圧縮機に求められる負荷が小さければ容量の小さい圧縮機１２Ｂを電動モータＭで駆動して効率を稼ぎ、求められる負荷が中程度であれば容量の大きい圧縮機１２ＡをガスエンジンＥＧの好適な回転数域で駆動して高効率運転を実現し、求められる負荷が大きければ大小２つの圧縮機１２Ａ，１２Ｂをそれぞれの駆動手段で同時に駆動してさらなる高効率運転を実現することができる。これにより、求められる負荷の大きさに関わらず高いＣＯＰ（成績係数）が得られる。
【００５４】
１基の圧縮機をガスエンジン等の内燃機関１基で駆動する従来の空気調和装置と比較すると、従来の空気調和装置は、求められる頻度の高い中程度の負荷に対応して高効率運転が行えるようにエンジンが調整されるため、小さな負荷が求められる場合はエンジンの回転数を高効率運転が行える回転数域から外して（回転数を下げて）運転させなければならず、効率が著しく低下する。大きな負荷が求められる場合にはエンジンの回転数を高効率運転が行える回転数域から外して（回転数を上げて）運転させなければならず、この場合も同様に効率が著しく低下する。このため、本実施形態の空気調和装置のように負荷の大きさに関わらず高いＣＯＰを維持することはできない。
【００５５】
さらに、ガスエンジンＥＧと電動モータＭとを、求められる負荷の大きさに応じてそれらを選択的に駆動したり同時に駆動したりするので、常時内燃機関を駆動させる従来の空気調和装置と比較してＣＯ₂やＮＯｘの排出量を抑えることができ、環境への配慮もなされる。
【００５６】
また、本実施形態の空気調和装置においては、中程度以上の負荷が求められる場合、室外熱交換器１１で屋外の空気から熱を汲み上げながら、ガスエンジンＥＧの排熱を利用して冷媒の加熱を行うので、さらなる高効率運転が可能である。
【００５７】
しかも、外気温が低く、従来の空気調和装置では頻繁にデフロスト（霜取り）運転に移行しそうな状況でも、室外熱交換器１１を使わず排熱利用熱交換器４０，４１を使用して冷媒の加熱が可能なので、デフロスト運転に伴う一時的な運転の中断がなく、安定した空調が得られる。
【００５８】
ところで、本実施形態においては容量の大きな圧縮機１２Ａの駆動手段としてガスエンジンＥＧを採用したが、当該駆動手段としての内燃機関には、ガスエンジン以外にマイクロガスタービンを採用することが可能である。また、その他の燃料を消費して回転力を取り出すことができる原動機を採用することも可能である。
【００５９】
本実施形態においては容量の小さな圧縮機１２Ｂの駆動手段として電動モータＭを採用したが、圧縮機１２Ｂの能力を活かせる回転数域で高効率運転が可能な内燃機関があればこれを圧縮機１２Ｂの駆動手段として採用することも可能である。
【００６０】
また、大小２つの圧縮機１２Ａ，１２Ｂの駆動手段をいずれも電動モータとし、これらに電力を供給する発電装置を併設し、該発電装置の排熱を排熱利用熱交換器４０に伝達して冷媒の加熱を行うようにすることも可能である。この場合の発電装置には、発電機に動力源としてガスエンジンやマイクロガスタービンを設置したものや、燃料電池等を採用することが好ましい。
【００６１】
上記の各実施形態においては大小２つの圧縮機１２Ａ，１２Ｂを具備する空気調和装置について説明したが、本発明は容量の異なる３つもしくはそれ以上の数の圧縮機を備える空気調和装置としても実施可能である。
【００６２】
【発明の効果】
以上説明したように、本発明によれば、圧縮機に求められる負荷が小さければ容量の小さな圧縮機をそれに見合った出力が得られる駆動手段で駆動して効率を稼ぎ、求められる負荷が中程度であれば容量の大きな圧縮機をそれに見合った出力が得られる駆動手段で駆動して高効率運転を実現し、求められる負荷が大きければ容量の異なる複数の圧縮機をそれぞれの駆動手段で同時に駆動してさらなる高効率運転を実現することができる。つまり、求められる負荷の大きさに応じて最も効率の良い運転が行える圧縮機を選択して駆動するので、負荷の大きさに関わらず高いＣＯＰが得られる。
【００６３】
さらに、容量の大きな圧縮機の駆動手段として内燃機関を採用するとともに、容量の小さな圧縮機の駆動手段として電動モータを採用し、求められる負荷の大きさに応じてそれらを選択的に駆動したり同時に駆動したりするので、常時内燃機関を駆動させる従来の空気調和装置と比較してＣＯ₂やＮＯｘの排出量を抑えることができ、環境にも優しい。
【００６４】
また、本発明によれば、圧縮機の駆動手段として採用した内燃機関の排熱を、暖房運転時に、容量の小さい圧縮機をガスポンプとして用いる構造を介して、冷媒の加熱に利用することにより、さらなる高効率運転が可能である。
【図面の簡単な説明】
【図１】本発明に係る空気調和装置の概略構成図である。
【図２】本発明による空気調和装置と従来のガスエンジン駆動型空気調和装置とについて、負荷の大きさに対応する成績係数を比較した図である。
【符号の説明】
１０室外ユニット
１１室外熱交換器
１２Ａ，１２Ｂ圧縮機
１４膨張弁
２０室内ユニット
２１室内熱交換器
３０ａ冷媒配管（中圧冷媒管路）
３０ｂ冷媒配管（一方の冷媒管路）
３０ｃ分岐冷媒配管（他方の冷媒管路）
３３バイパス配管（第１のバイパス管路）
３４バイパス配管（第２のバイパス管路）
３５膨張弁
４０排熱利用熱交換器（第１の排熱利用熱交換器）
４１排熱利用熱交換器（第２の排熱利用熱交換器）
４２，４３排熱伝達手段
５０制御部
ＥＧガスエンジン（内燃機関）
Ｍ電動モータ
Ｖ４開閉弁（第１の開閉弁）
Ｖ５開閉弁（第２の開閉弁）
Ｖ６開閉弁（第３の開閉弁）
Ｖ７開閉弁（第４の開閉弁）[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an air conditioner, and more particularly, to a heat pump type air conditioner having a structure in which refrigerant is heated using exhaust heat of a drive unit that drives a compressor.
[0002]
[Prior art]
There is a heat pump type air conditioner that employs an internal combustion engine such as a gas engine as a driving means of the compressor and further has a structure for heating the refrigerant by using the exhaust heat of the internal combustion engine. In this air conditioner, the rotational speed of the engine is changed according to the load, for example, the rotational speed is lowered when the load required for the compressor is small and the rotational speed is increased when the load is large. Therefore, the engine is required to have a wide rotation speed range.
[0003]
However, an internal combustion engine such as a gas engine has a limited rotation speed range in which high-efficiency operation is possible. Therefore, in a conventional air conditioner, the engine is adjusted so that high-efficiency operation is possible in a rotation speed range corresponding to a load range frequently required during normal operation.
[0004]
[Problems to be solved by the invention]
Since the conventional air conditioning apparatus performs the adjustment as described above, when a load having a magnitude outside the general range is required, the engine is caused to perform an inefficient operation. For this reason, it has been pointed out that the operating cost increases due to the deterioration of fuel consumption.
[0005]
In Japanese Patent Laid-Open No. 11-132594, a compressor having a large capacity is selectively driven by either an electric motor or an engine. When the load is small, the compressor is driven by the electric motor, and when the load is large A technique is disclosed in which a compressor is driven by an engine so that the engine is not operated inefficiently.
[0006]
However, in the technique disclosed in the above publication, for example, when a required load is small, a compressor having a large capacity is driven at a low speed, so that sufficient compression efficiency cannot be obtained. This is because when a compressor having a large capacity is driven at a low speed, leakage of the fluid to be compressed increases as compared with a case where the compressor is driven at a medium speed.
[0007]
Moreover, in the technique disclosed in the above publication, the electric motor is forced by driving a compressor having a large internal friction with an originally non-powerful electric motor, and as a result, the operation efficiency of the entire apparatus is high. Is hard to say.
[0008]
The present invention has been made in view of the above circumstances, and an object thereof is to provide an air conditioner capable of high-efficiency operation regardless of the required load.
[0009]
[Means for Solving the Problems]
As means for solving the above problems, an air conditioner having the following configuration is employed.
That is, the air conditioner according to claim 1 connects an indoor heat exchanger, an outdoor heat exchanger, an expansion valve, and a four-way valve through a refrigerant pipe, and two compressors having different capacities are connected in parallel to the refrigerant pipe. An air conditioner using an internal combustion engine as a drive means for driving a compressor having a large capacity among the two compressors.
One end of the two compressors is connected to the medium-pressure refrigerant pipe that conducts the medium-temperature and medium-pressure liquid refrigerant during the heating operation, and one refrigerant pipe located upstream of the small-capacity compressor of the two compressors. Providing a first bypass line connected to the other end;
The first bypass pipe uses a first on-off valve that opens and closes as necessary during heating operation and restricts introduction of refrigerant into the first bypass pipe, and uses exhaust heat of the internal combustion engine Then, a first exhaust heat utilization heat exchanger that heats and vaporizes the low-temperature and low-pressure liquid refrigerant is arranged in order from the medium-pressure refrigerant pipe side,
The second refrigerant pipe located upstream from the connection point with the first bypass pipe is opened and closed as necessary to restrict the introduction of the refrigerant into the small capacity compressor. Provided an on-off valve,
One end is connected to the intermediate-pressure refrigerant pipe located upstream from the connection point with the first bypass pipe in the heating operation, and located upstream of the compressor having a large capacity among the two compressors. Providing a second bypass line having the other end connected to the other refrigerant line,
The second bypass pipe is provided with a third on-off valve that opens and closes as necessary during heating operation to restrict introduction of the refrigerant into the second bypass pipe, and a medium- and intermediate-pressure liquid refrigerant is supplied at a low temperature. A pressure reducing valve for reducing the pressure to a low-pressure liquid refrigerant and a second exhaust heat utilization heat exchanger that heats and vaporizes the low-temperature and low-pressure liquid refrigerant by using the exhaust heat of the internal combustion engine in order from the intermediate pressure refrigerant pipe side Side by side,
The intermediate pressure refrigerant pipe located on the downstream side in the heating operation from the connection point with the first bypass pipe is opened and closed as necessary to restrict the introduction of the refrigerant to the outdoor heat exchanger. A fourth on-off valve is provided.
[0010]
According to a second aspect of the present invention, in the air conditioner according to the first aspect, a gas engine is employed as a driving means for driving a compressor having a large capacity among the two compressors.
[0011]
An air conditioner according to a third aspect of the present invention is the air conditioner according to the first or second aspect, wherein an electric motor is used as a driving means for driving a small capacity of the two compressors.
[0012]
The air conditioner according to claim 4 is the air conditioner according to claim 1, wherein at least one of the drive means provided individually in the two compressors is an electric motor, and the electric generator drives the electric motor. And the exhaust heat of the power generation apparatus is used for refrigerant heating during heating operation.
[0013]
The air conditioner according to claim 5 is the air conditioner according to claim 1, 2, 3 or 4, wherein the first and third on-off valves are closed during the heating operation, and the second and fourth on-off valves are closed. Open the valve to drive only the small compressor of the two compressors, or close the first and second on-off valves and open the third and fourth on-off valves to open the two compressors. Of these, only the one having a large capacity is driven, or the first and fourth on-off valves are opened and the second and third on-off valves are closed to drive the two compressors simultaneously. , And selectively executing according to a required load.
[0014]
The air conditioner according to claim 6 is the air conditioner according to claim 1, 2, 3, 4 or 5, wherein the first, second and fourth on-off valves are closed and the third on-off valve is opened. Then, the operation of driving only the one having a large capacity among the two compressors is executed according to the required load and the outdoor temperature.
[0015]
An air conditioner according to a seventh aspect is the air conditioner according to the first, second, third, fourth, fifth, or sixth aspect, wherein the first and third on-off valves are closed during the cooling operation. 4 is opened to drive only the small compressor of the two compressors, or the first, second and third on-off valves are closed and the fourth on-off valve is opened. Either only the compressor having a large capacity is driven, or the first and third on-off valves are closed and the second and fourth on-off valves are opened to drive the two compressors simultaneously. The operation is selectively performed according to a required load.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment according to the present invention will be described with reference to FIGS.
FIG. 1 shows a heat pump type air conditioner having a structure in which two compressors having different capacities are individually driven by a gas engine and an electric motor. This air conditioner includes an outdoor unit 10 and an indoor unit 20, which are connected by a refrigerant pipe 30 that conducts a refrigerant, an electric wiring (not shown), and the like.
[0017]
The outdoor unit 10 includes an outdoor heat exchanger 11 that exchanges heat between outdoor air and a refrigerant, and two compressors 12A that send the refrigerant to the outdoor heat exchanger 11 or an indoor heat exchanger 21 described later. 12B, a four-way valve 13 that switches the flow direction of the refrigerant flowing through the refrigerant pipe 30, an expansion valve 14 that is used during heating operation, a receiver 15 that separates the refrigerant into gas and liquid, and outdoor air to the outdoor heat exchanger 11. And an outdoor fan 16 that circulates the refrigerant, and is connected via a refrigerant pipe 30 to constitute a part of the refrigerant circulation system.
[0018]
The two compressors 12 </ b> A and 12 </ b> B have different capacities, and are connected in parallel to the refrigerant circulation system including the above-described devices and the refrigerant pipe 30 in the outdoor unit 10. Of the compressors 12A and 12B, a gas engine (internal combustion engine) EG is adopted as a driving means for the compressor 12A having a large capacity, and an electric motor M is adopted as a driving means for the compressor 12B having a small capacity.
[0019]
The gas engine EG can perform high-efficiency operation with good fuel efficiency when driven by utilizing the capacity of the compressor 12A corresponding to a medium load (that is, in a rotational speed range corresponding to the capacity of the compressor 12A). Has been adjusted. The electric motor M has an appropriate output so that it can be operated comfortably when driven by utilizing the capacity of the compressor 12B corresponding to a small load (that is, in a rotational speed range corresponding to the capacity of the compressor 12B). Is selected.
[0020]
Accumulators 17A and 17B are individually provided on the upstream side of the compressors 12A and 12B, and check valves V1 for preventing the reverse flow of the refrigerant to the compressors are provided on the downstream side, respectively. ing. Oil separators 18A and 18B are provided with oil return pipes 19 for returning the oil separated from the gas refrigerant to the upstream side of compressors 12A and 12B, respectively.
[0021]
The refrigerant pipe 30 before and after the expansion valve 14 is provided with a bypass pipe 31 that bypasses the expansion valve 14, and the bypass pipe 31 has a check valve V2 that prevents the refrigerant from flowing into the bypass pipe 31 during heating operation. Is provided.
[0022]
In the indoor unit 20, indoor air exchanger 21 that performs heat exchange between indoor air and refrigerant, an electromagnetic expansion valve 22 that is used during cooling operation, and indoor air are circulated through the indoor heat exchanger 21. An indoor fan 23 is provided, and is connected via a refrigerant pipe 30 to constitute a refrigerant circulation system together with the outdoor unit 10.
[0023]
The refrigerant pipe 30 before and after the electromagnetic expansion valve 22 is provided with a bypass pipe 32 that bypasses the electromagnetic expansion valve 22, and the bypass pipe 32 has a check valve V3 that prevents the refrigerant from flowing into the bypass pipe 32 during cooling operation. Is provided.
[0024]
Further, the outdoor unit 10 communicates with the outdoor heat exchanger 11 and the indoor heat exchanger 21, and the liquid refrigerant after passing through the indoor heat exchanger 21 that is a medium temperature and medium pressure during heating operation (that is, the indoor heat exchanger 21 that is a condenser). One end is connected to a refrigerant pipe (intermediate pressure refrigerant pipe) 30a that conducts the refrigerant), and the other end is connected to a branch refrigerant pipe (one refrigerant pipe) 30b located on the upstream side of the compressor 12B having a small capacity. Is connected to the bypass pipe (first bypass pipe line) 33.
[0025]
The bypass pipe 33 is opened and closed as necessary, and an on-off valve (first on-off valve) V4 that restricts introduction of the liquid refrigerant to the bypass pipe 33, and low-temperature and low-pressure liquid using the exhaust heat of the gas engine EG. An exhaust heat utilization heat exchanger (first exhaust heat utilization heat exchanger) 40 that heats and vaporizes the refrigerant is provided side by side from the refrigerant pipe 30a side.
[0026]
The branch refrigerant pipe 30b is provided with an on-off valve (second on-off valve) V5 that opens and closes as necessary to restrict introduction of the refrigerant into the compressor 12B.
[0027]
One end of the outdoor unit 10 is connected to the refrigerant pipe 30a located on the upstream side in the heating operation from the connection point with the bypass pipe 33, and the branched refrigerant pipe (the other side) located on the upstream side of the compressor 12A having a large capacity. The refrigerant pipe) 30c is provided with a bypass pipe (second bypass pipe) 34 having the other end connected thereto.
[0028]
In the bypass pipe 34, an on-off valve (third on-off valve) V6 that opens and closes as necessary to restrict introduction of the refrigerant into the bypass pipe 34, and depressurizes the medium-temperature and medium-pressure liquid refrigerant to a low-temperature and low-pressure liquid refrigerant. An expansion valve (pressure reduction valve) 35, a waste heat utilization heat exchanger (second waste heat utilization heat exchanger) 41 for heating and vaporizing a low-temperature and low-pressure liquid refrigerant using the exhaust heat of the gas engine EG, and refrigerant piping They are arranged in order from the 30a side.
[0029]
Furthermore, in the outdoor unit 10, the refrigerant pipe 30 a located downstream from the connection point with the bypass pipe 33 during heating operation is opened and closed as necessary to restrict introduction of the refrigerant into the outdoor heat exchanger 11. An on-off valve (fourth on-off valve) V7 is provided.
[0030]
Between the gas engine EG and the exhaust heat utilization heat exchanger 40, there is provided exhaust heat transfer means 42 for transmitting the exhaust heat of the gas engine EG and exchanging heat with the refrigerant in the exhaust heat utilization heat exchanger 40. Similar exhaust heat transfer means 43 is also provided between the gas engine EG and the exhaust heat utilization heat exchanger 41. The exhaust heat transfer means 42 and 43, for example, guide the exhaust of the gas engine EG directly to the exhaust heat utilization heat exchangers 40 and 41, and the cooling water heated by the gas engine EG to the exhaust heat utilization heat exchangers 40 and 41. It is the one that conducts heat indirectly by guiding it.
[0031]
Further, the air conditioner is provided with a control unit 50 that performs control of individually driving each of the compressors or driving both of them according to loads required for the two compressors 12A and 12B. Yes. The control unit 50 controls the driving of the compressors 12A and 12B, and switches the four-way valve 13 and the on-off valves V4, V5, V6, and V7 according to switching between cooling operation / heating operation and the required load. It comes to perform control.
[0032]
The manner of operation of the air conditioner configured as described above will be divided into a cooling operation and a heating operation, and further explained for each load size required in each operation state.
[Cooling operation at low load]
In this mode, only the compressor 12B having a small capacity is driven by the electric motor M. The on-off valves V4 and V6 are closed, and the on-off valves V5 and V7 are opened.
The refrigerant is compressed by the compressor 12B to become a high-temperature and high-pressure gas refrigerant, and flows into the outdoor heat exchanger 11 through the oil separator 18B and the four-way valve 13. In the outdoor heat exchanger 11, the high-temperature and high-pressure gas refrigerant gives heat to the outdoor air taken in by the outdoor fan 16 to exhaust heat, and condenses and liquefies itself to become a medium-temperature and medium-pressure liquid refrigerant.
[0033]
This medium-temperature / medium-pressure liquid refrigerant bypasses the expansion valve 14 and is separated into gas and liquid by the receiver 15, then sent to the indoor unit 20 through the refrigerant pipe 30, and decompressed in the process of passing through the electromagnetic expansion valve 22. It becomes a low-temperature and low-pressure liquid refrigerant and flows into the indoor heat exchanger 21. In the indoor heat exchanger 21, the low-temperature and low-pressure liquid refrigerant takes heat from the indoor air taken in by the indoor fan 23, cools it, and evaporates and vaporizes itself to become a low-temperature and low-pressure gas refrigerant. The low-temperature and low-pressure gas refrigerant is sent to the outdoor unit 10 through the refrigerant pipe 30, and is sucked and compressed into the compressor 12B through the four-way valve 13 and the accumulator 17B. Thereafter, the above process is repeated.
[0034]
[Cooling operation: Medium load]
In this mode, only the compressor 12A having a large capacity is driven by the gas engine EG. The on-off valves V4, V5, V6 are closed, and the on-off valve V7 is opened. In this mode, the compressor is simply switched from the small capacity 12B to the large capacity 12A, and the operation is the same as when the load is low. Note that the oil separator and the accumulator functioning in accordance with the switching of the compressor are switched to those provided corresponding to each.
[0035]
[Cooling operation at high load]
In this mode, the compressors 12A and 12B are simultaneously driven by the respective driving means. The on-off valves V4 and V6 are closed, and the on-off valves V5 and V7 are opened. In this mode, only the two compressors 12A and 12B are driven at the same time, and the manner of operation is the same as during low load or medium load.
[0036]
[Heating operation; low load]
In this mode, only the compressor 12B having a small capacity is driven by the electric motor M. The on-off valves V4 and V6 are closed and V5 and V7 are opened.
The refrigerant is compressed by the compressor 12B to become a high-temperature and high-pressure gas refrigerant, sent to the indoor unit 20 through the oil separator 18B and the four-way valve 13, and flows into the indoor heat exchanger 21. In the indoor heat exchanger 21, the high-temperature and high-pressure gas refrigerant heats the indoor air taken in by the indoor fan 23 and heats it, and condenses and liquefies itself to become a medium-temperature and medium-pressure liquid refrigerant.
[0037]
This medium-temperature / medium-pressure liquid refrigerant bypasses the electromagnetic expansion valve 22, is sent to the outdoor unit 10 through the refrigerant pipe 30, is separated into gas and liquid by the receiver 15, and then depressurized in the process of passing through the expansion valve 14. It becomes a low-temperature and low-pressure liquid refrigerant and flows into the outdoor heat exchanger 11. In the outdoor heat exchanger 11, the low-temperature and low-pressure liquid refrigerant takes heat from the outdoor air taken in by the outdoor fan 16, and evaporates and vaporizes itself to become a low-temperature and low-pressure gas refrigerant. This low-temperature and low-pressure gas refrigerant is sucked and compressed into the compressor 12B through the four-way valve 13 and the accumulator 17B. Thereafter, the above process is repeated.
[0038]
[Heating operation: Medium load]
In this mode, only the compressor 12A having a large capacity is driven by the gas engine EG. The on-off valves V4 and V5 are closed, and the on-off valves V6 and V7 are opened.
The refrigerant is compressed by the compressor 12A to become a high-temperature and high-pressure gas refrigerant, is sent to the indoor unit 20 through the oil separator 18A and the four-way valve 13, and flows into the indoor heat exchanger 21. In the indoor heat exchanger 21, the high-temperature and high-pressure gas refrigerant gives heat to the indoor air taken in by the indoor fan 23 and heats it, and condenses and liquefies itself to become a medium-temperature and medium-pressure liquid refrigerant (up to this point) Just by switching the compressor from 12B to 12A, the way of operation is the same as at low load).
[0039]
This medium-temperature / medium-pressure liquid refrigerant bypasses the electromagnetic expansion valve 22, is sent to the outdoor unit 10 through the refrigerant pipe 30, is separated into gas and liquid by the receiver 15, and then partially flows into the bypass pipe 34. The remaining liquid refrigerant that did not flow into the bypass pipe 34 is reduced in pressure in the process of passing through the expansion valve 14 to become a low-temperature and low-pressure liquid refrigerant, flows into the outdoor heat exchanger 11 and takes heat from outdoor air, Evaporates and vaporizes into a low-temperature and low-pressure gas refrigerant.
[0040]
The medium-temperature and medium-pressure liquid refrigerant that has flowed into the bypass pipe 34 is reduced in pressure in the process of passing through the expansion valve 35, becomes a low-temperature and low-pressure liquid refrigerant, and flows into the exhaust heat utilization heat exchanger 41. In the exhaust heat utilization heat exchanger 41, the low-temperature and low-pressure liquid refrigerant is heated by using the exhaust heat transmitted from the gas engine EG via the exhaust heat transfer means 43, and is evaporated and vaporized. Become.
[0041]
The low-temperature and low-pressure gas refrigerant evaporated and vaporized in the outdoor heat exchanger 11 and the low-temperature and low-pressure gas refrigerant evaporated and vaporized in the exhaust heat utilization heat exchanger 41 are combined by the accumulator 17A and sucked into the compressor 12A. Thereafter, the above process is repeated.
[0042]
[Heating operation; high load]
In this mode, the compressors 12A and 12B are simultaneously driven by the respective driving means. The on-off valves V4, V5, V7 are opened, and the on-off valve V6 is closed.
The refrigerant is discharged from the compressors 12A and 12B in a high-temperature and high-pressure gas state, merges through the oil separators 18A and 18B, is sent to the indoor unit 20 through the four-way valve 13, and flows into the indoor heat exchanger 21. In the indoor heat exchanger 21, the high-temperature and high-pressure gas refrigerant heats the indoor air taken in by the indoor fan 23 and heats it, and condenses and liquefies itself to become a medium-temperature and medium-pressure liquid refrigerant.
[0043]
This medium-temperature and medium-pressure liquid refrigerant bypasses the electromagnetic expansion valve 22, is sent to the outdoor unit 10 through the refrigerant pipe 30, and is separated into gas and liquid by the receiver 15, and then part of the liquid refrigerant flows into the bypass pipe 33. The remaining liquid refrigerant that did not flow into the bypass pipe 33 is reduced in pressure in the process of passing through the expansion valve 14 to become a low-temperature and low-pressure liquid refrigerant, flows into the outdoor heat exchanger 11, and takes heat from outdoor air. Evaporates and vaporizes into a low-temperature and low-pressure gas refrigerant.
[0044]
The medium-temperature medium-pressure liquid refrigerant that has flowed into the bypass pipe 33 flows into the exhaust heat utilization heat exchanger 40, is heated using the exhaust heat transmitted from the gas engine EG through the exhaust heat transfer means 42, and is evaporated. Vaporizes into a medium-temperature and medium-pressure gas refrigerant.
[0045]
The low-temperature and low-pressure gas refrigerant evaporated and vaporized in the outdoor heat exchanger 11 is sucked and compressed into the compressor 12A through the accumulator 17A. The medium-temperature and medium-pressure gas refrigerant evaporated and vaporized in the exhaust heat utilization heat exchanger 40 is sucked into the compressor 12B through the accumulator 17B. The compressor 12B in this case functions as a gas pump, and discharges a medium-temperature / medium-pressure gas refrigerant as a high-temperature / high-pressure gas refrigerant. Thereafter, the above process is repeated.
[0046]
[Heating operation; low outside temperature, low load]
In this mode, only the compressor 12A having a large capacity is driven by the gas engine EG. The on-off valves V4, V5, V7 are closed, and the on-off valve V6 is opened.
The refrigerant is compressed by the compressor 12A to become a high-temperature and high-pressure gas refrigerant, is sent to the indoor unit 20 through the oil separator 18A and the four-way valve 13, and flows into the indoor heat exchanger 21. In the indoor heat exchanger 21, the high-temperature and high-pressure gas refrigerant heats the indoor air taken in by the indoor fan 23 and heats it, and condenses and liquefies itself to become a medium-temperature and medium-pressure liquid refrigerant.
[0047]
This medium-temperature / medium-pressure liquid refrigerant bypasses the electromagnetic expansion valve 22, is sent to the outdoor unit 10 through the refrigerant pipe 30, is separated into gas and liquid by the receiver 15, and then flows into the bypass pipe 34. The medium-temperature and medium-pressure liquid refrigerant that has flowed into the bypass pipe 34 is reduced in pressure in the process of passing through the expansion valve 35, becomes a low-temperature and low-pressure liquid refrigerant, and flows into the exhaust heat utilization heat exchanger 41. In the exhaust heat utilization heat exchanger 41, the low-temperature and low-pressure liquid refrigerant is heated by using the exhaust heat transmitted from the gas engine EG via the exhaust heat transfer means 43, and is evaporated and vaporized. Become.
[0048]
The low-temperature and low-pressure gas refrigerant evaporated and vaporized in the exhaust heat utilization heat exchanger 41 is sucked and compressed into the compressor 12A through the accumulator 17A. Thereafter, the above process is repeated.
[0049]
[Heating operation; low outside temperature, medium / high load]
In this mode, the compressors 12A and 12B are simultaneously driven by the respective driving means. The on-off valves V4 and V6 are opened, and the on-off valves V5 and V7 are closed.
The refrigerant is discharged from the compressors 12A and 12B in a high-temperature and high-pressure gas state, merges through the oil separators 18A and 18B, is sent to the indoor unit 20 through the four-way valve 13, and flows into the indoor heat exchanger 21. In the indoor heat exchanger 21, the high-temperature and high-pressure gas refrigerant heats the indoor air taken in by the indoor fan 23 and heats it, and condenses and liquefies itself to become a medium-temperature and medium-pressure liquid refrigerant.
[0050]
This medium-temperature / medium-pressure liquid refrigerant bypasses the electromagnetic expansion valve 22, is sent to the outdoor unit 10 through the refrigerant pipe 30, and is separated into gas and liquid by the receiver 15, and then partially flows into the bypass pipe 33 and remains. Flows into the bypass pipe 34. The medium-temperature medium-pressure liquid refrigerant that has flowed into the bypass pipe 33 flows into the exhaust heat utilization heat exchanger 40, is heated using the exhaust heat transmitted from the gas engine EG through the exhaust heat transfer means 42, and is evaporated. Vaporizes into a medium-temperature and medium-pressure gas refrigerant.
[0051]
The medium-temperature and medium-pressure liquid refrigerant that has flowed into the bypass pipe 34 is reduced in pressure in the process of passing through the expansion valve 35, becomes a low-temperature and low-pressure liquid refrigerant, and flows into the exhaust heat utilization heat exchanger 41. In the exhaust heat utilization heat exchanger 41, the low-temperature and low-pressure liquid refrigerant is heated by using the exhaust heat transmitted from the gas engine EG via the exhaust heat transfer means 43, and is evaporated and vaporized. Become.
[0052]
The medium-temperature and medium-pressure gas refrigerant evaporated and vaporized in the exhaust heat utilization heat exchanger 40 is sucked into the compressor 12B through the accumulator 17B. The compressor 12B in this case functions as a gas pump, and discharges a medium-temperature / medium-pressure gas refrigerant as a high-temperature / high-pressure gas refrigerant. The low-temperature and low-pressure gas refrigerant evaporated and vaporized in the exhaust heat utilization heat exchanger 41 is sucked and compressed into the compressor 12A through the accumulator 17A. Thereafter, the above process is repeated.
[0053]
In the air conditioner that operates as described above, as shown in FIG. 2, if the load required for the compressor is small, the compressor 12B having a small capacity is driven by the electric motor M to increase the efficiency, and the required load. If the load is medium, the compressor 12A having a large capacity is driven in a suitable rotational speed range of the gas engine EG to achieve high-efficiency operation. If the required load is large, the two compressors 12A and 12B of large and small are respectively connected. Further high efficiency operation can be realized by simultaneously driving with the driving means. As a result, a high COP (coefficient of performance) can be obtained regardless of the required load.
[0054]
Compared with a conventional air conditioner that drives a single compressor with a single internal combustion engine such as a gas engine, the conventional air conditioner is capable of high-efficiency operation in response to the required medium load. Since the engine is adjusted so that it can do so, if a small load is required, the engine speed must be removed from the speed range where high-efficiency operation can be performed (lowering the speed), and the efficiency is extremely high. descend. When a large load is required, the engine speed must be removed from the engine speed range where high-efficiency operation can be performed (by increasing the engine speed), and in this case, the efficiency is also significantly reduced. For this reason, high COP cannot be maintained irrespective of the magnitude | size of load like the air conditioning apparatus of this embodiment.
[0055]
Further, the gas engine EG and the electric motor M are selectively driven or simultaneously driven according to the required load, so that the gas engine EG and the electric motor M are compared with the conventional air conditioner that always drives the internal combustion engine. CO ₂ And NOx emissions can be reduced, giving consideration to the environment.
[0056]
In addition, in the air conditioner of the present embodiment, when a medium or higher load is required, the refrigerant is heated by using the exhaust heat of the gas engine EG while pumping heat from the outdoor air in the outdoor heat exchanger 11. As a result, further high-efficiency operation is possible.
[0057]
Moreover, even in a situation where the outside air temperature is low and the conventional air conditioner is likely to frequently shift to the defrosting operation, the exhaust heat utilization heat exchangers 40 and 41 are used without using the outdoor heat exchanger 11. Since heating is possible, there is no temporary interruption of operation due to defrost operation, and stable air conditioning can be obtained.
[0058]
In the present embodiment, the gas engine EG is used as the driving means of the compressor 12A having a large capacity. However, in addition to the gas engine, a micro gas turbine can be used as the internal combustion engine as the driving means. . It is also possible to employ a prime mover that can consume other fuel and extract the rotational force.
[0059]
In the present embodiment, the electric motor M is used as the driving means of the compressor 12B having a small capacity. However, if there is an internal combustion engine capable of high-efficiency operation in the rotation speed range that can utilize the ability of the compressor 12B, this is used as the compressor. It is also possible to employ as 12B driving means.
[0060]
In addition, the driving means of the two large and small compressors 12A and 12B are both electric motors, and a power generation device that supplies electric power to these motors is provided, and the exhaust heat of the power generation device is transmitted to the exhaust heat utilization heat exchanger 40. It is also possible to heat the refrigerant. In this case, it is preferable to employ a power generator in which a gas engine or a micro gas turbine is installed as a power source in the generator, or a fuel cell.
[0061]
In each of the above-described embodiments, the air conditioner including two large and small compressors 12A and 12B has been described. However, the present invention can also be implemented as an air conditioner including three or more compressors having different capacities. Is possible.
[0062]
【The invention's effect】
As described above, according to the present invention, if the load required for the compressor is small, the compressor having a small capacity is driven by a driving means that can obtain an output corresponding to the compressor, and the efficiency is obtained. If this is the case, drive a high-capacity compressor with a drive unit that can provide an output that matches it, and achieve high-efficiency operation. If the required load is large, drive multiple compressors with different capacities simultaneously with each drive unit. Thus, further efficient operation can be realized. That is, since the compressor that can perform the most efficient operation is selected and driven according to the required load, a high COP can be obtained regardless of the load.
[0063]
Furthermore, an internal combustion engine is adopted as a driving means for a compressor having a large capacity, and an electric motor is adopted as a driving means for a compressor having a small capacity, and these are selectively driven according to the required load. Compared to the conventional air conditioner that always drives the internal combustion engine. ₂ And NOx emissions can be reduced, and it is environmentally friendly.
[0064]
Further, according to the present invention, the exhaust heat of the internal combustion engine adopted as the driving means of the compressor is used for heating the refrigerant through the structure using the compressor having a small capacity as the gas pump during the heating operation. Further high efficiency operation is possible.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of an air conditioner according to the present invention.
FIG. 2 is a diagram comparing the coefficient of performance corresponding to the magnitude of load for an air conditioner according to the present invention and a conventional gas engine driven air conditioner.
[Explanation of symbols]
10 Outdoor unit
11 Outdoor heat exchanger
12A, 12B compressor
14 Expansion valve
20 indoor units
21 Indoor heat exchanger
30a Refrigerant piping (medium pressure refrigerant piping)
30b Refrigerant piping (one refrigerant line)
30c Branch refrigerant pipe (the other refrigerant pipe)
33 Bypass pipe (first bypass pipe)
34 Bypass piping (second bypass conduit)
35 Expansion valve
40 Waste heat utilization heat exchanger (first waste heat utilization heat exchanger)
41 Waste heat utilization heat exchanger (second waste heat utilization heat exchanger)
42, 43 Waste heat transfer means
50 Control unit
EG gas engine (internal combustion engine)
M Electric motor
V4 On-off valve (first on-off valve)
V5 On-off valve (second on-off valve)
V6 On-off valve (third on-off valve)
V7 On-off valve (fourth on-off valve)

Claims

An indoor heat exchanger, an outdoor heat exchanger, an expansion valve, and a four-way valve are connected via a refrigerant pipe, and two compressors having different capacities are connected in parallel to the refrigerant pipe, and the two compressors are individually connected. Provided with a driving means, and an air conditioner adopting an internal combustion engine as a driving means for driving a compressor having a large capacity among the two compressors,
One end of the two compressors is connected to the medium-pressure refrigerant pipe that conducts the medium-temperature and medium-pressure liquid refrigerant during the heating operation, and one refrigerant pipe located upstream of the small-capacity compressor of the two compressors. Providing a first bypass line connected to the other end;
The first bypass pipe uses a first on-off valve that opens and closes as necessary during heating operation and restricts introduction of refrigerant into the first bypass pipe, and uses exhaust heat of the internal combustion engine Then, a first exhaust heat utilization heat exchanger that heats and vaporizes the low-temperature and low-pressure liquid refrigerant is arranged in order from the medium-pressure refrigerant pipe side,
The second refrigerant pipe located upstream from the connection point with the first bypass pipe is opened and closed as necessary to restrict the introduction of the refrigerant into the small capacity compressor. Provided an on-off valve,
One end is connected to the intermediate-pressure refrigerant pipe located upstream from the connection point with the first bypass pipe in the heating operation, and located upstream of the compressor having a large capacity among the two compressors. Providing a second bypass line having the other end connected to the other refrigerant line,
The second bypass pipe is provided with a third on-off valve that opens and closes as necessary during heating operation to restrict introduction of the refrigerant into the second bypass pipe, and a medium- and intermediate-pressure liquid refrigerant is supplied at a low temperature. A pressure reducing valve for reducing the pressure to a low-pressure liquid refrigerant and a second exhaust heat utilization heat exchanger that heats and vaporizes the low-temperature and low-pressure liquid refrigerant by using the exhaust heat of the internal combustion engine in order from the intermediate pressure refrigerant pipe side Side by side,
The intermediate pressure refrigerant pipe located on the downstream side in the heating operation from the connection point with the first bypass pipe is opened and closed as necessary to restrict the introduction of the refrigerant to the outdoor heat exchanger. An air conditioner provided with a fourth on-off valve.

The air conditioner according to claim 1, wherein a gas engine is employed as a driving means for driving a compressor having a large capacity among the two compressors.

The air conditioner according to claim 1 or 2, wherein an electric motor is used as a driving means for driving a small capacity of the two compressors.

At least one of the drive means individually provided in the two compressors is an electric motor, and a power generation device that drives the electric motor is provided, and the exhaust heat of the power generation device is used for refrigerant heating during heating operation. The air conditioner according to claim 1.

During the heating operation, the first and third on-off valves are closed and the second and fourth on-off valves are opened to drive only the smaller one of the two compressors. Close the two on-off valves and open the third and fourth on-off valves to drive only the large compressor of the two compressors, or open the first and fourth on-off valves and open the second 5. The operation according to claim 1, wherein the third on-off valve is closed and the two compressors are driven simultaneously according to a required load. The air conditioning apparatus described.

The first, second, and fourth on-off valves are closed and the third on-off valve is opened to drive only the large capacity of the two compressors according to the required load and outdoor temperature. The air conditioning apparatus according to claim 1, 2, 3, 4 or 5.

During the cooling operation, the first and third on-off valves are closed and the second and fourth on-off valves are opened to drive only the small compressor of the two compressors, or the first and second The third on-off valve is closed and the fourth on-off valve is opened to drive only the large capacity of the two compressors, or the first and third on-off valves are closed and the second, The first on-off valve is opened to drive the two compressors at the same time, and the operation is selectively executed according to a required load. The air conditioning apparatus according to 5 or 6.