JP4258032B2

JP4258032B2 - Refrigeration equipment

Info

Publication number: JP4258032B2
Application number: JP08554098A
Authority: JP
Inventors: 真理佐田; 忠竿尾; 昌弘岡; 靖史堀
Original assignee: Daikin Industries Ltd
Current assignee: Daikin Industries Ltd
Priority date: 1998-03-31
Filing date: 1998-03-31
Publication date: 2009-04-30
Anticipated expiration: 2018-03-31
Also published as: JPH11281174A

Description

【０００１】
【発明の属する技術分野】
本発明は、熱源である１次側回路と、ポンプを用いることなく冷媒を循環させて熱源の温熱又は冷熱を搬送する２次側回路とから成る冷凍装置に関し、該冷凍装置における加圧手段に係るものである。
【０００２】
【従来の技術】
従来より、冷凍装置としては、熱源である１次側回路と、ポンプを用いることなく冷媒を循環させて熱源の温熱又は冷熱を搬送する２次側回路とから成り、熱源の温熱又は冷熱を２次側回路の利用側熱交換器へ搬送して利用するように構成されたものが知られている。
【０００３】
この種の冷凍装置には、１次側回路を、圧縮機を備えて蒸気圧縮式冷凍サイクルを構成する熱源側冷媒回路とする一方、２次側回路を、特開平９−１７８２１７号公報に開示されているような熱搬送装置から成る利用側冷媒回路とし、熱源で生成した温熱又は冷熱を利用側熱交換器に搬送して室内の空気調和を行う空気調和装置に構成されたものがある。
【０００４】
具体的に、１次側回路には、２次側回路の冷媒に温熱又は冷熱を供給する主熱交換器が設けられている。そして、該主熱交換器において、１次側回路の１次側冷媒と２次側回路の２次側冷媒とが熱交換し、２次側冷媒が凝縮又は蒸発して１次側冷媒に温熱又は冷熱を供給する。
【０００５】
一方、２次側回路には、液冷媒を貯留した一対のタンクと、駆動用の加熱熱交換器と、駆動用の冷却熱交換器とが設けられている。該加熱熱交換器には、１次側回路で冷熱を生成する冷房運転時において、１次側回路の高圧液冷媒が供給され、該高圧液冷媒と２次側回路の液冷媒とが熱交換し、２次側冷媒が加熱されて蒸発して２次側回路に高圧が生成する。また、１次側回路で温熱を生成する暖房運転時においては、該加熱熱交換器へ１次側回路の高圧ガス冷媒が供給され、該高圧ガス冷媒と２次側回路の液冷媒とが熱交換し、２次側冷媒が蒸発して２次側回路に高圧を生成する。該冷却熱交換器には、運転状態とは無関係に、常に１次側回路の低圧液冷媒が供給され、該低圧液冷媒と２次側回路のガス冷媒とが熱交換し、２次側冷媒が冷却されて凝縮して２次側回路に低圧が生成する。そして、この高圧を一方のタンクに供給すると同時に、低圧を他方のタンクに供給し、一方のタンクからの液冷媒の押し出しと、他方のタンクへの液冷媒の回収とを同時に行うことにより、２次側回路での冷媒の循環動作を得るようにしている。
【０００６】
以上のようにして、２次側回路を冷媒が循環し、１次側回路の温熱又は冷熱を利用側熱交換器へ搬送している。そして、利用側熱交換器は、温熱を受けて放熱動作を行って室内の暖房を行い、また、冷熱を受けて吸熱動作を行って室内の冷房を行うようにしている。
【０００７】
【発明が解決しようとする課題】
上述のように、従来の冷凍装置は、１次側回路で冷熱を生成する冷房運転時において、加熱熱交換器で１次側回路の高圧液冷媒により２次側回路の液冷媒を加熱して蒸発させて高圧を生成するようにしている。一方、運転状態によっては、１次側回路の高圧液冷媒の温度が所定値よりも低下する場合がある。この場合には、加熱熱交換器で所定の高圧を生成することができず、２次側回路における冷媒の循環量が低下するため、冷凍装置が充分な能力を発揮できなくなるという問題があった。
【０００８】
具体的に、１次側回路では、圧縮機から吐出された高圧ガス冷媒を外気との熱交換によって凝縮させる場合があり、この凝縮した冷媒が高圧液冷媒となる。この場合、外気温が低い場合は凝縮した後に更に冷却され、高圧液冷媒の温度が所定値よりも低下してしまう。つまり、所定温度よりも低温となった１次側回路の高圧液冷媒によって２次側冷媒を蒸発させるため、駆動用の加熱熱交換器における２次側冷媒の蒸発量が減少して、高圧を充分に生成することができない場合があった。
【０００９】
本発明は、かかる点に鑑みてなされたものであり、その目的とするところは、いかなる運転状態においても２次側回路である利用側冷媒回路における冷媒循環量を確保し、常に所定能力を発揮するようにすることにある。
【００１０】
【課題を解決するための手段】
本発明は、熱源側冷媒回路（10）で冷熱を生成する利用側熱交換器（HEX1）の吸熱動作時において、搬送手段（30）の加圧手段（HEX3）に対して、熱源側冷媒回路（10）の高圧ガス冷媒を供給可能とするようにしたものである。
【００１１】
具体的に、本発明が講じた第１，第２の各解決手段は、温熱又は冷熱を生成する熱源側冷媒回路（10）と、搬送手段（30）により冷媒を循環させ、上記熱源側冷媒回路（10）の温熱又は冷熱を利用側熱交換器（HEX1）へ搬送して該利用側熱交換器（HEX1）に吸熱動作又は放熱動作を行わせる利用側冷媒回路（20）とを備えた冷凍装置を前提としている。そして、上記搬送手段（30）を、高圧を生成する加圧手段（HEX3）と低圧を生成する減圧手段（HEX4）とを備えて、該加圧手段（HEX3）で生成した高圧と減圧手段（HEX4）で生成した低圧との差により利用側冷媒回路（20）の冷媒に循環駆動力を付与するように構成し、上記加圧手段（HEX3）を、熱源側冷媒回路（10）の冷媒の供給を受け、該冷媒との熱交換により利用側冷媒回路（20）の液冷媒を加熱し蒸発させて高圧を生成するように構成し、上記熱源側冷媒回路（10）を、圧縮機（11）を備えて蒸気圧縮式冷凍サイクルを構成する閉回路により形成して、上記利用側熱交換器（HEX1）の吸熱動作時に、該熱源側冷媒回路（10）の凝縮器から流出した高圧液冷媒と上記圧縮機（11）から吐出された高圧ガス冷媒とを上記加圧手段（HEX3）へ供給可能に構成するものである。
【００１２】
そして、上記第１の解決手段は、上述した構成に加えて、熱源側冷媒回路（10）を、圧縮機（11）を備える１つの閉回路により形成し、加圧手段（HEX3）に供給する冷媒を上記高圧液冷媒と上記高圧ガス冷媒とに切り換え可能に構成するものである。
【００１３】
また、上記第２の解決手段は、上述した構成に加えて、熱源側冷媒回路（10）を、それぞれが圧縮機（11a〜11c）を備える複数の閉回路により構成し、上記熱源側冷媒回路（ 10 ）を構成する複数の閉回路（ 10a,10b,10c ）は、そのうちの一部の閉回路（ 10b ）が、加圧手段（HEX3b）に上記高圧液冷媒だけを供給するように構成され、残りの閉回路（ 10a ）の少なくとも一つが、加圧手段（HEX3a）に上記高圧ガス冷媒だけを供給する状態と、加圧手段（ HEX3a ）に上記高圧液冷媒と上記高圧ガス冷媒の何れも供給しない状態とに切り換え可能に構成されるものである。
【００１４】
−作用−
上記第１，第２の各解決手段では、熱源側冷媒回路（10）において、圧縮機（11）から吐出された高圧ガス冷媒が凝縮して高圧液冷媒となり、この高圧液冷媒は減圧された後に蒸発し、蒸発したガス冷媒が再び圧縮機（11）に吸入されて、この循環を繰り返す。そして、該熱源側冷媒回路（10）は、冷媒が凝縮する際に生成する温熱を利用側冷媒回路（20）に供給する運転と、蒸発する際に生成する冷熱を利用側冷媒回路（20）に供給する運転とを切り換えて行う。更に、熱源側冷媒回路（10）は、利用側冷媒回路（20）の冷媒を加熱するために、利用側冷媒回路（20）の加圧手段（HEX3）に冷媒を供給する。その際、該熱源側冷媒回路（10）は、冷熱を利用側冷媒回路（20）に供給する利用側熱交換器（HEX1）の吸熱動作時において、加圧手段（HEX3）に上記高圧ガス冷媒と高圧液冷媒と供給することが可能である。
【００１５】
一方、利用側冷媒回路（20）では、加圧手段（HEX3）が高圧を生成すると同時に、減圧手段（HEX4）が低圧を生成し、この高圧と低圧との圧力差により循環駆動力を付与されて冷媒が循環する。この回路内を循環する冷媒によって、熱源側冷媒回路（10）で生成した温熱又は冷熱が、利用側熱交換器（HEX1）へ搬送される。そして、該利用側熱交換器（HEX1）は、該温熱を受けて外部へ熱を放出する放熱動作と、該冷熱を受けて外部から熱を吸収する吸熱動作とを行う。その際、上記加圧手段（HEX3）は、熱源側冷媒回路（10）の冷媒の供給を受け、該冷媒と利用側冷媒回路（20）の液冷媒とを熱交換させる。これによって、利用側冷媒回路（20）の冷媒が加熱されて蒸発し、加圧手段（HEX3）において高圧が生成する。
【００１６】
そして、上記第１の解決手段では、熱源側冷媒回路（10）が１つの閉回路によって構成されているので、この閉回路を循環する冷媒のうち高圧液冷媒と高圧ガス冷媒とが、相互に切り換えられて加圧手段（HEX3）に供給される。
【００１７】
また、上記第２の解決手段では、熱源側冷媒回路（10）は複数の閉回路によって構成される。これら複数の閉回路では、そのうちの一部の閉回路（ 10b ）において、高圧液冷媒だけが加圧手段（HEX3a,HEX3b）に供給され、残りの閉回路（ 10a ）の少なくとも一つにおいて、加圧手段（ HEX3a ）に高圧ガス冷媒だけが供給される状態と、加圧手段（ HEX3a ）に上記高圧液冷媒と上記高圧ガス冷媒の何れも供給されない状態とが切り換わる。
【００１８】
【発明の効果】
上述のように、本解決手段によれば、該加圧手段（HEX3）に熱源側冷媒回路（10）の高圧ガス冷媒を供給することができるので、常に利用側冷媒回路（20）の冷媒循環量を所定量に保つことができる。つまり、この高圧ガス冷媒は、圧縮機（11）から吐出されたガス冷媒であって、何れの運転状態においても、利用側冷媒回路（20）の液冷媒を蒸発させるのに充分な高温状態となっている。従って、該高圧ガス冷媒を加圧手段（HEX3）に供給することによって、利用側冷媒回路（20）の液冷媒を確実に加熱して蒸発させることができ、充分な高圧を生成することができる。この結果、運転状態に拘わらず、利用側冷媒回路（20）における冷媒の循環を充分に確保することができ、熱源側冷媒回路（10）の温熱又は冷熱を利用側熱交換器（HEX1）へ搬送して、運転能力を常に確保することができる。
【００１９】
特に、加圧手段（HEX3）において、熱源側冷媒回路（10）の高圧液冷媒により充分な高圧を生成できる場合には、該高圧液冷媒を加圧手段（HEX3）に供給する運転を行うことができる。つまり、熱源側冷媒回路（10）の高圧ガス冷媒を加圧手段（HEX3）に供給する運転に比して、熱源側冷媒回路（10）における冷凍サイクルのＣＯＰ（成績係数）が高い。そこで、上記の解決手段は、熱源側冷媒回路（10）の高圧液冷媒を加圧手段（HEX3）に供給する運転も可能にしている。この結果、従来通りの高圧液冷媒を加圧手段（HEX3）に供給する運転を行って熱源側冷媒回路（10）のＣＯＰを高く維持することができると共に、従来では充分な能力を発揮できなかった運転状態においても、高圧ガス冷媒を加圧手段（HEX3）に供給することによって、運転能力を常に確保することができる。
【００２０】
熱源側冷媒回路（10）において、高圧液冷媒を加圧手段（HEX3）に供給する方が、高圧ガス冷媒を加圧手段（HEX3）に供給する場合比してＣＯＰが高いのは、以下の理由による。該高圧液冷媒を加圧手段（HEX3）に供給する運転の場合、高圧ガス冷媒を凝縮させて成る高圧液冷媒によって利用側冷媒回路（20）の液冷媒を加熱する。従って、この加熱に要する熱量が余分に熱源側冷媒回路（10）から放熱され、高圧ガス冷媒を加圧手段（HEX3）に供給する運転の場合に比して、高圧ガス冷媒が凝縮して成る高圧液冷媒のサブクールが増大する。そして、このエンタルピの低下した液冷媒を減圧した後に蒸発させて冷熱を生成するため、該液冷媒の蒸発に際しての吸熱量が増大する。即ち、液冷媒の蒸発により生成される冷熱量が増大し、この結果、熱源側冷媒回路（10）におけるＣＯＰが高くなる。
【００２１】
【発明の実施の形態１】
以下、本発明の実施形態を図面に基づいて詳細に説明する。本実施形態の冷凍装置は、図１に示すように、温熱又は冷熱を生成する熱源側冷媒回路（10）と、搬送手段である搬送回路（30）を備えて熱源側冷媒回路（10）の温熱又は冷熱を室内熱交換器（HEX1）へ搬送し利用する利用側冷媒回路（20）とを備えている。そして、上記冷凍装置は、利用側冷媒回路（20）の室内熱交換器（HEX1）の放熱動作又は吸熱動作によって室内の空気調和を行う空気調和装置に構成されている。以下、熱源側冷媒回路（10）を１次側回路（10）といい、利用側冷媒回路（20）を２次側回路（20）という。
【００２２】
上記２次側回路（20）は、主熱交換器（HEX2）と複数の室内ユニット（22）とを備えて成る主回路（21）に、２次側四路切換弁（23）を介して上記搬送回路（30）を接続して形成されている。該室内ユニット（22）は、利用側熱交換器である室内熱交換器（HEX1）と室内電動弁（EV）とを冷媒配管で直列に接続して構成されている。そして、各室内ユニット（22）の室内熱交換器（HEX1）側の一端は、それぞれ主ガス配管（24）を介して主熱交換器（HEX2）の上端部に接続されると共に、各室内ユニット（22）の室内電動弁（EV）側の一端は、それぞれ主液配管（25）を介して２次側四路切換弁（23）に接続されている。また、該主熱交換器（HEX2）の下端部は、主液配管（26）を介して２次側四路切換弁（23）に接続されている。以上のようにして、上記主回路（21）が形成される。
【００２３】
上記搬送回路（30）は、冷媒が充填されると共に、加圧手段である加熱熱交換器（HEX3）と、減圧手段である冷却熱交換器（HEX4）と、液冷媒を貯留する第１及び第２メインタンク（T1,T2）と、サブタンク（ST）とを備えている。上記加熱熱交換器（HEX3）は、１次側回路（10）の冷媒が供給され、該１次側冷媒と２次側回路（20）の液冷媒とを熱交換させ、該２次側冷媒を加熱し蒸発させて高圧を生成するように構成されている。上記冷却熱交換器（HEX4）は、１次側回路（10）の冷媒が供給され、該１次側冷媒と２次側回路（20）のガス冷媒とを熱交換させ、該２次側冷媒を冷却し凝縮させて低圧を生成するように構成されている。そして、加熱熱交換器（HEX3）の高圧を一方のメインタンク（T1,T2）に供給して該メインタンク（T1,T2）内の液冷媒を押し出すと同時に、冷却熱交換器（HEX4）の低圧を他方のメインタンク（T1,T2）に供給して該メインタンク（T1,T2）内へ液冷媒を回収する。以上のようにして、搬送回路（30）は、２次側回路（20）の冷媒に循環駆動力を付与するように構成されている。
【００２４】
具体的に、上記冷却熱交換器（HEX4）の上端部にはガス回収管（32）が接続されている。このガス回収管（32）は３本の分岐管（32a,32b,32c）に分岐されて、各分岐管（32a〜32c）が各メインタンク（T1,T2）及びサブタンク（ST）の上端部に個別に接続されている。これら各分岐管（32a〜32c）には、第１〜第３のタンク減圧電磁弁（SV-V1,SV-V2,SV-V3）が設けられている。また、この冷却熱交換器（HEX4）の下端部には液配管である液供給管（33）が接続されている。この液供給管（33）は２本の分岐管（33a,33b）に分岐され、各分岐管（33a,33b）が各メインタンク（T1,T2）の下端部にそれぞれ接続している。これら分岐管（33a,33b）には、各メインタンク（T1,T2）への冷媒の回収のみを許容する逆止弁（CV-2）が設けられている。
【００２５】
一方、上記加熱熱交換器（HEX3）の上端部にはガス供給管（31）が接続されている。このガス供給管（31）は、３本の分岐管（31a,31b,31c）に分岐され、各分岐管（31a〜31c）が上記ガス回収管（32）の分岐管（32a〜32c）に接続されている。これにより、該ガス供給管（31）の各分岐管（31a〜31c）が各メインタンク（T1,T2）及びサブタンク（ST）の上端部に個別に接続している。これら各分岐管（31a〜31c）には、第１〜第３のタンク加圧電磁弁（SV-P1,SV-P2,SV-P3）が設けられている。また、この加熱熱交換器（HEX3）の下端部には液回収管（34）が接続されている。この液回収管（34）はサブタンク（ST）の下端部に接続されている。この液回収管（34）には、サブタンク（ST）からの冷媒の流出のみを許容する逆止弁（CV-1）が設けられている。
【００２６】
尚、各メインタンク（T1,T2）は、冷却熱交換器（HEX4）よりも低い位置に設置されている。また、サブタンク（ST）は、加熱熱交換器（HEX3）よりも高い位置に設置されている。
【００２７】
また、各メインタンク（T1,T2）には回収用液配管（38）と押出し用液配管（37）とが接続されている。この回収用液配管（38）は２本の分岐管（38a,38b）に分岐され、各分岐管（38a,38b）が各メインタンク（T1,T2）の下端部にそれぞれ接続している。これら各分岐管（38a,38b）には、各メインタンク（T1,T2）への冷媒の流入のみを許容する逆止弁（CV-5）が設けられている。一方、押出し用液配管（37）は３本の分岐管（37a,37b,37c）に分岐され、各分岐管（37a〜37c）が上記回収用液配管（38）の分岐管（38a,38b）及び液回収管（34）に接続することにより、各メインタンク（T1,T2）及びサブタンク（ST）の下端部に接続している。これら分岐管（37a〜37c）のうち、各メインタンク（T1,T2）に接続する分岐管（37a,37b）には、メインタンク（T1,T2）下端からの冷媒の流出のみを許容する逆止弁（CV-3）が設けられる一方、サブタンク（ST）に接続する分岐管（37c）には、該サブタンク（ST）への冷媒の流入のみを許容する逆止弁（CV-4）が設けられている。
【００２８】
以上のように上記搬送回路（30）が構成されると共に、該搬送回路（30）の回収用液配管（38）及び押出し用液配管（37）が、２次側四路切換弁（23）を介して主回路（21）の主液配管（25,26）に接続されている。そして、上記２次側回路（20）は、一方のメインタンク（T1,T2）から押し出された液冷媒が押出し用液配管（37）を通って主回路（21）へ流れ、主回路（21）を循環した後に回収用液配管（38）を通って他方のメインタンク（T1,T2）に回収されるように構成される。また、２次側四路切換弁（23）を切り換えることによって、主回路（21）において冷媒の循環方向を反転可能に構成している。
【００２９】
上記１次側回路（10）は、圧縮機（11）、１次側四路切換弁（12）、室外熱交換器（HEX5）、第１膨張弁（EV-1）及び主熱交換器（HEX2）を順に主配管（5）により接続して成る閉回路であって、内部を冷媒が循環して温熱又は冷熱を生成する蒸気圧縮式冷凍サイクルを構成している。また、該１次側回路（10）は、搬送回路（30）の加熱熱交換器（HEX3）及び冷却熱交換器（HEX4）に接続され、これらの熱交換器（HEX3,HEX4）へ冷媒を供給するように構成されている。
【００３０】
上記加熱熱交換器（HEX3）は、室外熱交換器（HEX5）と第１膨張弁（EV-1）との間の主配管（5）に設けられている。具体的に、該加熱熱交換器（HEX3）の上端部は主配管（5）を介して室外熱交換器（HEX5）に接続され、下端部は主配管（5）を介して第１膨張弁（EV-1）に接続されている。また、加熱熱交換器（HEX3）と室外熱交換器（HEX5）との間には、室外熱交換器（HEX5）から加熱熱交換器（HEX3）へ向かう冷媒の流通のみを許容する逆止弁（CV-6）が設けられている。
【００３１】
上記冷却熱交換器（HEX4）は、第１分岐配管（1）を介して１次側回路（10）に接続されている。具体的に、該冷却熱交換器（HEX4）の上端部は圧縮機（11）と１次側四路切換弁（12）との間の主配管（5）を介して圧縮機（11）の吸入側に接続され、下端部は加熱熱交換器（HEX3）と第１膨張弁（EV-1）との間の主配管（5）に接続されている。また、該第１分岐配管（1）の冷却熱交換器（HEX4）の下端部と該主配管（5）との間には第２膨張弁（EV-2）が設けられている。
【００３２】
また、上記１次側回路（10）には、第２分岐配管（2）、第３分岐配管（3）及び第４分岐配管（4）が設けられている。そして、本発明の特徴として、該１次側回路（10）は、冷房運転時において、加熱熱交換器（HEX3）に高圧の液冷媒と高圧のガス冷媒とを供給可能に構成されている。
【００３３】
上記第２分岐配管（2）は、一端が圧縮機（11）と１次側四路切換弁（12）との間の主配管（5）を介して圧縮機（11）の吐出側に接続され、他端が加熱熱交換器（HEX3）と逆止弁（CV-6）との間に接続されている。また、該第２分岐配管（2）には、第１電磁弁（SV-1）が設けられている。そして、高圧のガス冷媒である圧縮機（11）の吐出ガスを加熱熱交換器（HEX3）へ供給するように構成されている。
【００３４】
上記第３分岐配管（3）は、一端が逆止弁（CV-6）と室外熱交換器（HEX5）との間に接続され、他端が加熱熱交換器（HEX3）と第１膨張弁（EV-1）との間に接続されている。また、該第３分岐配管（3）には、第２電磁弁（SV-2）が設けられている。そして、加熱熱交換器（HEX3）及び逆止弁（CV-6）をバイパスして冷媒を流すことができるように構成されている。
【００３５】
上記第４分岐配管（4）は、一端が第２膨張弁（EV-2）と主配管（5）との間の第１分岐配管（1）に接続され、他端が逆止弁（CV-6）と室外熱交換器（HEX5）との間に接続されている。また、該第４分岐配管（4）には、該一端から他端へ向かって順に、第３膨張弁（EV-3）と、該一端から他端に向かう冷媒の流通のみを許容する逆止弁（CV-7）とが設けられている。そして、暖房運転時に液冷媒が流通するように構成されている。
【００３６】
−運転動作−
冷房運転時における運転動作について説明する。
【００３７】
先ず、上記１次側回路（10）の動作について説明する。この運転時において、上記１次側回路（10）では、１次側四路切換弁（12）が図１に実線で示すように切り換えられ、第１膨張弁（EV-1）及び第２膨張弁（EV-2）が所定開度に調整され、第３膨張弁（EV-3）が閉鎖される。また、上記加熱熱交換器（HEX3）へ高圧の液冷媒を供給する場合には、第１電磁弁（SV-1）及び第２電磁弁（SV-2）が閉鎖される。
【００３８】
この状態において、図２に実線の矢印で示すように、１次側回路（10）内を冷媒が循環する。即ち、圧縮機（11）から吐出された高圧のガス冷媒は、１次側四路切換弁（12）を通って室外熱交換器（HEX5）へ流れ、室外熱交換器（HEX5）で外気と熱交換して凝縮して高圧の液冷媒となる。この高圧の液冷媒は、主配管（5）を通って加熱熱交換器（HEX3）へ流れ、加熱熱交換器（HEX3）で２次側回路（20）の液冷媒と熱交換して、該２次側回路（20）の液冷媒を蒸発させる。加熱熱交換器（HEX3）から流出した該高圧の液冷媒は分流されて、一部は主熱交換器（HEX2）へ向かって流れ、残りは冷却熱交換器（HEX4）へ向かって流れる。主熱交換器（HEX2）へ向かう高圧の液冷媒は、主配管（5）を流れ、第１膨張弁（EV-1）で減圧されて低圧の液冷媒となり、その後、主熱交換器（HEX2）において２次側回路（20）の冷媒と熱交換して蒸発する。その際、１次側回路（10）において冷熱が生成し、該冷熱が２次側回路（20）の冷媒に供給される。一方、冷却熱交換器（HEX4）へ向かう高圧の液冷媒は、第１分岐配管（1）を流れ、第２膨張弁（EV-2）で減圧されて低圧の液冷媒となり、その後、冷却熱交換器（HEX4）において２次側回路（20）のガス冷媒と熱交換して蒸発し、該２次側回路（20）のガス冷媒を凝縮させる。該主熱交換器（HEX2）及び冷却熱交換器（HEX4）で蒸発した１次側回路（10）の冷媒は、合流した後に圧縮機（11）に吸入され、この循環を繰り返す。
【００３９】
また、上記加熱熱交換器（HEX3）へ高圧のガス冷媒を供給する場合には、上述の状態において、第１電磁弁（SV-1）及び第２電磁弁（SV-2）を開放する。
【００４０】
この状態において、図３に実線の矢印で示すように、１次側回路（10）内を冷媒が循環する。即ち、圧縮機（11）から吐出された高圧のガス冷媒は分流されて、一部は室外熱交換器（HEX5）へ向かって流れ、残りは加熱熱交換器（HEX3）へ向かって流れる。室外熱交換器（HEX5）へ向かう高圧のガス冷媒は、主配管（5）を流れ、１次側四路切換弁（12）を通って室外熱交換器（HEX5）へ流れ、室外熱交換器（HEX5）で外気と熱交換して凝縮して高圧の液冷媒となる。この高圧の液冷媒は、主配管（5）を通って第３分岐配管（3）へ流れる。一方、加熱熱交換器（HEX3）へ向かう高圧のガス冷媒は、第２分岐配管（2）を通って加熱熱交換器（HEX3）へ流れ、加熱熱交換器（HEX3）で２次側回路（20）の液冷媒と熱交換して凝縮し、該２次側回路（20）の液冷媒を蒸発させる。該室外熱交換器（HEX5）及び加熱熱交換器（HEX3）で凝縮した高圧の液冷媒は、一旦合流した後に再び分流されて、一部は主熱交換器（HEX2）へ向かって流れ、残りは冷却熱交換器（HEX4）へ向かって流れる。その後、分流された高圧の液冷媒は、上述の加熱熱交換器（HEX3）へ高圧の液冷媒を供給する場合と同様に流れる。つまり、それぞれ第１膨張弁（EV-1）及び第２膨張弁（EV-2）で減圧され、主熱交換器（HEX2）及び冷却熱交換器（HEX4）で蒸発した後に互いに合流し、その後、圧縮機（11）に吸入されてこの循環を繰り返す。
【００４１】
以上のように、上記１次側回路（10）は、第１電磁弁（SV-1）及び第２電磁弁（SV-2）の開閉動作によって、高圧の液冷媒と高圧のガス冷媒とを切り換えて加熱熱交換器（HEX3）に供給する。
【００４２】
次に、上記２次側回路（20）の動作について説明する。搬送回路（30）の各電磁弁（SV-P1,SV-V2,SV-P3）が次の状態にあるところから説明する。第１メインタンク（T1）の加圧電磁弁（SV-P1）、サブタンク（ST）の加圧電磁弁（SV-P3）、第２メインタンク（T2）の減圧電磁弁（SV-V2）が開放されている。一方、第２メインタンク（T2）の加圧電磁弁（SV-P2）、第１メインタンク（T1）の減圧電磁弁（SV-V1）、サブタンク（ST）の減圧電磁弁（SV-V3）は閉鎖されている。また、２次側四路切換弁（23）は図１に実線で示すように切り換えられ、各室内ユニット（22）の室内電動弁（EV）は所定開度に調整されている。
【００４３】
この状態において、加熱熱交換器（HEX3）では、１次側回路（10）の冷媒と２次側回路（20）の液冷媒とが熱交換し、該２次側冷媒が加熱されて蒸発することにより高圧が生成する。この高圧は、ガス供給管（31）の分岐管（31a）を経て第１メインタンク（T1）に供給され、第１メインタンク（T1）が加圧される。このため、第１メインタンク（T1）に貯留された液冷媒が、図２の一点鎖線の矢印に示すように、第１メインタンク（T1）から押し出される。そして、第１メインタンク（T1）から押し出された液冷媒は、押出し用液配管（37）の分岐管（37a）から押出し用液配管（37）へ流れ、２次側四路切換弁（23）を通って主回路（21）の主液配管（25）へ流れる。
【００４４】
一方、冷却熱交換器（HEX4）では、１次側回路（10）の冷媒と２次側回路（20）のガス冷媒とが熱交換し、該２次側冷媒が冷却されて凝縮することにより低圧が生成する。この低圧は、ガス回収管（32）の分岐管（32b）を経て第２メインタンク（T2）に供給され、第２メインタンク（T2）が減圧される。このため、第２メインタンク（T2）には主回路（21）の液冷媒が回収される。つまり、図２の一点鎖線の矢印に示すように、主配管（5）の主液配管（26）の液冷媒が吸引され、２次側四路切換弁（23）、回収用液配管（38）、回収用液配管（38）の分岐管（38b）を順に流れて第２メインタンク（T2）に回収される。
【００４５】
上記２次側回路（20）の主回路（21）では、上述のような第１メインタンク（T1）からの液冷媒の押し出しと、第２メインタンク（T2）への液冷媒の回収とによって冷媒が循環し、１次側回路（10）の冷熱を室内熱交換器（HEX1）へ搬送して室内の冷房が行われる。具体的に、第１メインタンク（T1）からの押し出されて主液配管（25）へ流れた液冷媒は、各室内ユニット（22）へ分流される。その際、各室内電動弁（EV）の開度を調整することにより、各室内ユニット（22）へ流れる液冷媒の流量が調節される。各室内ユニット（22）へ分流した液冷媒は、各室内熱交換器（HEX1）で室内空気と熱交換を行って蒸発し、室内空気を冷却して調和空気を生成する。そして、この低温の調和空気が室内の冷房に供される。一方、各室内熱交換器（HEX1）で蒸発した冷媒は、合流して主ガス配管（24）を通って主熱交換器（HEX2）へ流れる。主熱交換器（HEX2）へ流れたガス冷媒は、１次側回路（10）の冷媒と熱交換を行い、該１次側冷媒が蒸発して生成した冷熱によって冷却されて凝縮し、再び液冷媒となる。この液冷媒は、主液配管（26）を流れ、回収用液配管（38）を通って第２メインタンク（T2）に回収される。
【００４６】
また、搬送回路（30）において、サブタンク（ST）は、加熱熱交換器（HEX3）と均圧されている。このため、図２に一点鎖線の矢印で示すように、該サブタンク（ST）内の液冷媒が液回収管（34）を経て加熱熱交換器（HEX3）に供給される。この供給された液冷媒は加熱熱交換器（HEX3）内で蒸発して第１メインタンク（T1）内の加圧に寄与する。その後、このサブタンク（ST）内の液冷媒の殆どが加熱熱交換器（HEX3）に供給されると、サブタンク（ST）の加圧電磁弁（SV-P3）が閉鎖されると共に、サブタンク（ST）の減圧電磁弁（SV-V3）が開放される。これにより、サブタンク（ST）内は低圧になり、図２に破線の矢印で示すように、押出し用液配管（37）を流れている冷媒の一部が回収される。
【００４７】
このような動作を所定時間行った後、搬送回路（30）の電磁弁（SV-P1,SV-P2,…）を切換える。つまり、第１メインタンク（T1）の加圧電磁弁（SV-P1）、第２メインタンク（T2）の減圧電磁弁（SV-V2）、サブタンク（ST）の減圧電磁弁（SV-V3）を閉鎖する。第２メインタンク（T2）の加圧電磁弁（SV-P2）、第１メインタンク（T1）の減圧電磁弁（SV-V1）、サブタンク（ST）の加圧電磁弁（SV-P3）を開放する。
【００４８】
これにより、第１メインタンク（T1）の内圧が低圧となり、逆に、第２メインタンク（T2）及びサブタンク（ST）の内圧が高圧となる。このため、第２メインタンク（T2）から押し出された液冷媒が上述と同様に循環して第１メインタンク（T1）に回収される冷媒循環状態となり、また、サブタンク（ST）内の液冷媒が加熱熱交換器（HEX3）に供給される。この場合にも、このサブタンク（ST）内の液冷媒の殆どが加熱熱交換器（HEX3）に供給されると、サブタンク（ST）の加圧電磁弁（SV-P3）が閉鎖されると共に、サブタンク（ST）の減圧電磁弁（SV-V3）が開放されて、サブタンク（ST）への冷媒の回収が行われる。
【００４９】
以上のように各電磁弁（SV-P1,SV-P2,…）が切換え動作を行い、冷媒が第１メインタンク（T1）から押し出されて第２メインタンク（T2）に回収される動作と、冷媒が第２メインタンク（T2）から押し出されて第２メインタンク（T2）に回収される動作とが交互に行われる。そして、２次側回路（20）の主回路（21）において冷媒が循環し、室内の冷房が行われる。
【００５０】
次に、暖房運転時における運転動作について説明する。この運転時において、上記１次側回路（10）では、１次側四路切換弁（12）が図１に破線で示すように切り換えられ、第１膨張弁（EV-1）が全開に調整され、第２膨張弁（EV-2）及び第３膨張弁（EV-3）が所定開度に調整される。また、第１電磁弁（SV-1）が開放され、第２電磁弁（SV-2）が閉鎖される。
【００５１】
この状態において、図４に実線の矢印で示すように、１次側回路（10）内を冷媒が循環する。即ち、圧縮機（11）から吐出された高圧のガス冷媒は分流されて、一部は主熱交換器（HEX2）へ向かって流れ、残りは加熱熱交換器（HEX3）へ向かって流れる。主熱交換器（HEX2）へ向かう高圧のガス冷媒は、１次側四路切換弁（12）を通って主熱交換器（HEX2）へ流れ、主熱交換器（HEX2）で２次側回路（20）の冷媒と熱交換して凝縮して高圧の液冷媒となる。その際、１次側回路（10）において温熱が生成し、該温熱が２次側回路（20）の冷媒に供給される。一方、加熱熱交換器（HEX3）へ向かう高圧のガス冷媒は、第２分岐配管（2）を通って加熱熱交換器（HEX3）へ流れ、加熱熱交換器（HEX3）で２次側回路（20）の液冷媒と熱交換して凝縮し、該２次側回路（20）の液冷媒を蒸発させる。該主熱交換器（HEX2）及び加熱熱交換器（HEX3）で凝縮して高圧の液冷媒となった冷媒は、一旦合流して第１分岐配管（1）を流れた後に再び分流されて、一部は室外熱交換器（HEX5）へ向かって流れ、残りは冷却熱交換器（HEX4）へ向かって流れる。室外熱交換器（HEX5）へ向かう高圧の液冷媒は、第４分岐配管（4）を流れ、第３膨張弁（EV-3）で減圧されて低圧の液冷媒となり、その後、主配管（5）を通って室外熱交換器（HEX5）へ流れ、室外熱交換器（HEX5）において外気と熱交換して蒸発する。一方、冷却熱交換器（HEX4）へ向かう高圧の液冷媒は、第２膨張弁（EV-2）で減圧されて低圧の液冷媒となり、その後、冷却熱交換器（HEX4）において２次側回路（20）のガス冷媒と熱交換して蒸発し、該２次側回路（20）のガス冷媒を凝縮させる。該室外熱交換器（HEX5）及び冷却熱交換器（HEX4）で蒸発した１次側回路（10）の冷媒は、合流した後に圧縮機（11）に吸入され、この循環を繰り返す。
【００５２】
また、上記２次側回路（20）では、該２次側回路（20）の搬送回路（30）において、加熱熱交換器（HEX3）の高圧と冷却熱交換器（HEX4）の低圧とを第１及び第２メインタンク（T1,T2）に供給し、上述の冷房運転時と同様に動作して、各メインタンク（T1,T2）での液冷媒の押し出しと回収とを行う。
【００５３】
上記２次側回路（20）の主回路（21）では、各メインタンク（T1,T2）での液冷媒の押し出しと回収とによって冷媒が循環し、１次側回路（10）の温熱を室内熱交換器（HEX1）へ搬送して室内の暖房が行われる。搬送回路（30）の押出し用液配管（37）から主回路（21）へ流れる液冷媒は、２次側四路切換弁（23）と主液配管（26）とを順に通り、主熱交換器（HEX2）へ流れる。主熱交換器（HEX2）へ流れた液冷媒は、１次側回路（10）の冷媒と熱交換し、該１次側冷媒が凝縮して生成した温熱によって加熱されて蒸発する。主熱交換器（HEX2）で蒸発したガス冷媒は、主ガス配管（24）を流れ、各室内ユニット（22）へ分流される。その際、各室内電動弁（EV）の開度を調整することにより、各室内ユニット（22）へ流れるガス冷媒の流量が調節される。各室内ユニット（22）へ分流したガス冷媒は、各室内熱交換器（HEX1）で室内空気と熱交換を行って凝縮し、室内空気を加熱して調和空気を生成する。そして、この高温の調和空気が室内の暖房に供される。一方、各室内熱交換器（HEX1）で凝縮した冷媒は、合流して主液配管（25）、２次側四路切換弁（23）を順に通り、搬送回路（30）の回収用液配管（38）に流れる。以上のように、２次側回路（20）の主回路（21）において冷媒が循環し、室内の暖房が行われる。
【００５４】
−実施形態１の効果−
本実施形態１によれば、１次側回路（10）における高圧の液冷媒の温度が所定値よりも低下する運転状態においても、該加熱熱交換器（HEX3）に１次側回路（10）の高圧のガス冷媒を供給することができる。例えば、上記の運転状態としては、低外気温時における冷房運転が考えられる。つまり、圧縮機（11）から吐出された高圧のガス冷媒は、室外熱交換器（HEX5）で外気との熱交換により凝縮して高圧の液冷媒となる。従って、外気温が低い場合には凝縮した冷媒が更に外気によって冷却され、高圧の液冷媒の温度が低下する。一方、圧縮機（11）から吐出された高圧のガス冷媒は、上述の運転状態においても、２次側回路（20）の液冷媒を蒸発させるのに充分な高温状態となっている。このため、該高圧のガス冷媒を加熱熱交換器（HEX3）に供給することによって、２次側回路（20）の液冷媒を確実に加熱して蒸発させることができ、充分な高圧を生成することができる。この結果、運転状態に拘わらず、２次側回路（20）における冷媒の循環を充分に確保することができ、１次側回路（10）の温熱又は冷熱を室内熱交換器（HEX1）へ搬送することにより、空調能力を常に確保することができる。
【００５５】
特に、加熱熱交換器（HEX3）において、１次側回路（10）の高圧の液冷媒により充分な高圧を生成できる場合には、該高圧の液冷媒を加熱熱交換器（HEX3）に供給する運転を行うことができる。つまり、１次側回路（10）の高圧のガス冷媒を加熱熱交換器（HEX3）に供給する運転に比して、１次側回路（10）における冷凍サイクルのＣＯＰ（成績係数）が高い。そこで、本実施形態は、１次側回路（10）の高圧の液冷媒を加熱熱交換器（HEX3）に供給する運転も可能にしている。この結果、従来通りの高圧の液冷媒を加熱熱交換器（HEX3）に供給する運転を行って１次側回路（10）のＣＯＰを高く維持することができると共に、従来では充分な能力を発揮できなかった運転状態、例えば低外気温時における冷房運転においても、高圧のガス冷媒を加熱熱交換器（HEX3）に供給することによって、空調能力を常に確保することができる。
【００５６】
１次側回路（10）において、高圧の液冷媒を加熱熱交換器（HEX3）に供給する方が、高圧のガス冷媒を加熱熱交換器（HEX3）に供給する場合比してＣＯＰが高いのは、以下の理由による。該高圧の液冷媒を加熱熱交換器（HEX3）に供給する運転の場合、高圧のガス冷媒を凝縮させて成る高圧の液冷媒によって２次側回路（20）の液冷媒を加熱する。従って、この加熱に要する熱量が余分に１次側回路（10）から放熱され、高圧のガス冷媒を加熱熱交換器（HEX3）に供給する運転の場合に比して、高圧のガス冷媒が凝縮して成る高圧の液冷媒のサブクールが増大する。そして、このエンタルピの低下した液冷媒を減圧した後に蒸発させて冷熱を生成するため、該液冷媒の蒸発に際しての吸熱量が増大する。即ち、液冷媒の蒸発により生成される冷熱量が増大し、この結果、１次側回路（10）におけるＣＯＰが高くなる。
【００５７】
【発明の実施の形態２】
本発明の実施形態２は、上記実施形態１が１つの閉回路により１次側回路（10）を構成したのに代えて、図５に示すように、第１回路（10a）、第２回路（10b）及び第３回路（10c）の３つの閉回路により１次側回路（10）を構成するものである。この第１〜第３回路（10a〜10c）は、それぞれが圧縮機（11a〜11c）を備え、内部を冷媒が循環して温熱又は冷熱を生成する蒸気圧縮式冷凍サイクルを構成している。
【００５８】
２次側回路（20）は、上記実施形態１の２次側回路（20）とほぼ同様に構成されるが、１次側回路（10）を３つの閉回路により構成したことに伴い、以下の点で実施形態１のものと異なる。先ず、２次側回路（20）の主回路（21）には、第１主熱交換器（HEX2a）、第２主熱交換器（HEX2b）及び第３主熱交換器（HEX2c）の３つの主熱交換器が設けられている。該第１〜第３主熱交換器（HEX5a〜HEX5c）は、互いに並列に接続され、各主熱交換器（HEX5a〜HEX5c）の上端部が主回路（21）の主ガス配管（24）に、下端部が主液配管（26）にそれぞれ接続されている。また、２次側回路（20）の搬送回路（30）には、第１加熱熱交換器（HEX3a）及び第２加熱熱交換器（HEX3b）が設けられている。該第１及び第２加熱熱交換器（HEX3a,HEX3b）は、各加熱熱交換器（HEX3a,HEX3b）の上端部が搬送回路（30）のガス供給管（31）に、下端部が液回収管（34）にそれぞれ接続され、加圧手段に構成されている。その他の構成は、上記実施形態１の２次側回路（20）と同様である。
【００５９】
上記１次側回路（10）を構成する第１回路（10a）は、第１圧縮機（11a）、第１四路切換弁（12a）、第１室外熱交換器（HEX5a）、第１膨張弁（EV-1）、第２膨張弁（EV-2）及び第１主熱交換器（HEX2a）を順に主配管（5a）により接続して成る閉回路である。また、該第１回路（10a）は、搬送回路（30）の第１加熱熱交換器（HEX3a）及び冷却熱交換器（HEX4）に接続され、これらの熱交換器（HEX3a,HEX4）へ冷媒を供給するように構成されている。
【００６０】
上記第１加熱熱交換器（HEX3a）は、第１分岐配管（1）を介して熱源側冷媒回路（10）に接続されている。具体的に、該第１加熱熱交換器（HEX3a）の上端部が第１圧縮機（11a）と第１四路切換弁（12a）との間の主配管（5a）を介して第１圧縮機（11a）の吐出側に接続され、下端部が第１膨張弁（EV-1）と第２膨張弁（EV-2）との間の主配管（5a）に接続されている。また、該第１分岐配管（1）における第１加熱熱交換器（HEX3a）の下端部と該主配管との間には電磁弁（SV）が設けられている。そして、本発明の特徴として、該第１加熱熱交換器（HEX3a）には、第１分岐配管（1）を通じて、第１圧縮機（11a）から吐出された高圧のガス冷媒を供給可能に構成されている。
【００６１】
上記冷却熱交換器（HEX4）は、第２分岐配管（2）を介して第１回路（10a）に接続されている。具体的に、該冷却熱交換器（HEX4）の上端部が圧縮機と１次側四路切換弁（12）との間の主配管を介して圧縮機の吸入側に接続され、下端部が第１膨張弁（EV-1）と第２膨張弁（EV-2）との間の主配管（5a）に接続されている。また、該第２分岐配管（2）の冷却熱交換器（HEX4）の下端部と該主配管との間には第３膨張弁（EV-3）が設けられている。
【００６２】
上記１次側回路（10）を構成する第２回路（10b）は、第２圧縮機（11b）、第２四路切換弁（12b）、第２室外熱交換器（HEX5b）、第４膨張弁（EV-4）及び第２主熱交換器（HEX2b）を順に主配管（5b）により接続して成る閉回路である。また、該第２回路（10b）は、搬送回路（30）の第２加熱熱交換器（HEX3b）に接続され、この熱交換器（HEX3b）へ冷媒を供給するように構成されている。
【００６３】
上記第２加熱熱交換器（HEX3b）は、第２室外熱交換器（HEX5b）と第４膨張弁（EV-4）との間の主配管に設けられている。具体的に、該第２加熱熱交換器（HEX3b）の上端部は主配管（5b）を介して第２室外熱交換器（HEX5b）に接続され、下端部は主配管（5b）を介して第４膨張弁（EV-4）に接続されている。また、第２加熱熱交換器（HEX3b）と第４膨張弁（EV-4）との間には、第２加熱熱交換器（HEX3b）から第４膨張弁（EV-4）へ向かう冷媒の流通のみを許容する逆止弁（CV-6）が設けられている。そして、該第２加熱熱交換器（HEX3b）には、高圧の液冷媒を供給可能に構成されている。
【００６４】
また、上記第２回路（10b）には、第３分岐配管（3）が設けられている。該第３分岐配管（3）は、一端が逆止弁（CV-6）と第４膨張弁（EV-4）との間に接続され、他端が第２加熱熱交換器（HEX3b）と第２室外熱交換器（HEX5b）との間に接続されている。また、該第３分岐配管（3）には、該一端から他端へ向かって順に、第５膨張弁（EV-5）と、該一端から他端に向かう冷媒の流通のみを許容する逆止弁（CV-7）とが設けられている。そして、第２加熱熱交換器（HEX3b）及び逆止弁（CV-6）をバイパスして冷媒を流すことができるように構成されている。
【００６５】
上記１次側回路（10）を構成する第３回路（10c）は、第３圧縮機（11c）、第３四路切換弁（12c）、第３室外熱交換器（HEX5c）、第６膨張弁（EV-6）及び第３主熱交換器（HEX2c）を順に主配管（5c）により接続して成る閉回路である。そして、該第３回路（10c）は、上記２次側回路（20）への温熱又は冷熱の供給のみを行うように構成されている。
【００６６】
−運転動作−
先ず、冷房運転時における運転動作について説明する。
【００６７】
この運転時において、上記第１回路（10a）では、第１四路切換弁（12a）が図５に実線で示すように切り換えられ、第１膨張弁（EV-1）が全開に調整され、第２膨張弁（EV-2）及び第３膨張弁（EV-3）が所定開度に調整される。また、上記第１加熱熱交換器（HEX3a）へ高圧のガス冷媒を供給する場合には、電磁弁（SV）が開放される。
【００６８】
この状態において、図６に実線の矢印で示すように、第１回路（10a）内を冷媒が循環する。即ち、第１圧縮機（11a）から吐出された高圧のガス冷媒は分流されて、一部は第１室外熱交換器（HEX5a）へ向かって流れ、残りは第１加熱熱交換器（HEX3a）へ向かって流れる。第１室外熱交換器（HEX5a）へ向かう高圧のガス冷媒は、主配管（5a）を流れ、第１四路切換弁（12a）を通って第１室外熱交換器（HEX5a）へ流れ、第１室外熱交換器（HEX5a）で外気と熱交換して凝縮して高圧の液冷媒となる。一方、第１加熱熱交換器（HEX3a）へ向かう高圧のガス冷媒は、第１分岐配管（1）を通って第１加熱熱交換器（HEX3a）へ流れ、第１加熱熱交換器（HEX3a）で２次側回路（20）の液冷媒と熱交換して凝縮し、該２次側回路（20）の液冷媒を蒸発させる。上記第１室外熱交換器（HEX5a）で凝縮して高圧の液冷媒となった冷媒は、第１膨張弁（EV-1）を通った後に分流され、一部は冷却熱交換器（HEX4）へ向かって流れ、残りはそのまま主配管（5a）を流れる。冷却熱交換器（HEX4）へ向かう高圧の液冷媒は、第２分岐配管（2）を流れ、第３膨張弁（EV-3）で減圧されて低圧の液冷媒となり、その後、冷却熱交換器（HEX4）において２次側回路（20）のガス冷媒と熱交換して蒸発し、該２次側回路（20）のガス冷媒を凝縮させる。一方、主配管（5a）を流れる高圧の液冷媒は、第１加熱熱交換器（HEX3a）で凝縮した高圧の液冷媒と合流して主配管（5a）を流れ、第２膨張弁（EV-2）で減圧されて低圧の液冷媒となり、その後、第１主熱交換器（HEX2a）において２次側回路（20）の冷媒と熱交換して蒸発する。その際、第１回路（10a）において冷熱が生成し、該冷熱が２次側回路（20）の冷媒に供給される。該第１主熱交換器（HEX2a）及び冷却熱交換器（HEX4）で蒸発した第１回路（10a）の冷媒は、合流した後に第１圧縮機（11a）に吸入され、この循環を繰り返す。
【００６９】
また、上記第１加熱熱交換器（HEX3a）へ高圧のガス冷媒を供給しない場合には、上述の状態において、電磁弁（SV）を閉鎖する。この状態において、第１分岐配管（1）へは冷媒が流れず、第１回路（10a）の高圧のガス冷媒は第１加熱熱交換器（HEX3a）へ流れない。
【００７０】
上記第２回路（10b）では、第２四路切換弁（12b）が図５に実線で示すように切り換えられ、第４膨張弁（EV-4）が所定開度に調整される。
【００７１】
この状態において、図６に実線の矢印で示すように、第２回路（10b）内を冷媒が循環する。即ち、第２圧縮機（11b）から吐出された高圧のガス冷媒は、第２四路切換弁（12b）を通って第２室外熱交換器（HEX5b）へ流れ、第２室外熱交換器（HEX5b）で外気と熱交換して凝縮して高圧の液冷媒となる。この高圧の液冷媒は、主配管（5b）を通って第２加熱熱交換器（HEX3b）へ流れ、第２加熱熱交換器（HEX3b）で２次側回路（20）の液冷媒と熱交換して、該２次側回路（20）の液冷媒を蒸発させる。加熱熱交換器から流出した該高圧の液冷媒は、主配管（5b）を流れ、第４膨張弁（EV-4）で減圧されて低圧の液冷媒となり、その後、第２主熱交換器（HEX2b）において２次側回路（20）の冷媒と熱交換して蒸発する。その際、第２回路（10b）において冷熱が生成し、該冷熱が２次側回路（20）の冷媒に供給される。該第２主熱交換器（HEX2b）で蒸発した第２回路（10b）の冷媒は、その後、第２圧縮機（11b）に吸入され、この循環を繰り返す。
【００７２】
上記第３回路（10c）では、第３四路切換弁（12c）が図５に実線で示すように切り換えられ、第６膨張弁（EV-6）が所定開度に調整される。
【００７３】
この状態において、図６に実線の矢印で示すように、第２回路（10b）内を冷媒が循環する。即ち、第３圧縮機（11c）から吐出された高圧のガス冷媒は、第３四路切換弁（12c）を通って第３室外熱交換器（HEX5c）へ流れ、第３室外熱交換器（HEX5c）で外気と熱交換して凝縮して高圧の液冷媒となる。この高圧の液冷媒は、主配管（5c）を流れ、第６膨張弁（EV-6）で減圧されて低圧の液冷媒となり、その後、第３主熱交換器（HEX2c）において２次側回路（20）の冷媒と熱交換して蒸発する。その際、第３回路（10c）において冷熱が生成し、該冷熱が２次側回路（20）の冷媒に供給される。該第３主熱交換器（HEX2c）で蒸発した第３回路（10c）の冷媒は、その後、第３圧縮機（11c）に吸入され、この循環を繰り返す。
【００７４】
そして、上記第１〜第３回路（10a〜10c）から成る１次側回路（10）は、第２加熱熱交換器（HEX3b）に第２回路（10b）の高圧の液冷媒を供給して充分な高圧を生成できる運転状態においては、第１回路（10a）の電磁弁（SV）を閉鎖して、第１加熱熱交換器（HEX3a）へ第１回路（10a）の冷媒を供給しない。即ち、この運転状態においては、第２加熱熱交換器（HEX3b）のみで生成する高圧を用いて、２次側回路（20）の冷媒を循環させる。一方、第２加熱熱交換器（HEX3b）において充分な高圧を生成できない運転状態においては、２次側回路（20）の冷媒を確実に循環させることができなくなる。この場合、上記１次側回路（10）は、第１回路（10a）の電磁弁（SV）を開放することにより、第１加熱熱交換器（HEX3a）へ第１回路（10a）の高圧のガス冷媒を供給する。これによって、上述の運転状態においても第１加熱熱交換器（HEX3a）で高圧が生成し、該高圧を用いて２次側回路（20）の冷媒を循環させることができる。
【００７５】
また、上記２次側回路（20）において、搬送回路（30）では、第１及び第２加熱熱交換器（HEX3a,HEX3b）における２次側回路（20）の冷媒の蒸発によって高圧が生成し、冷却熱交換器（HEX4）における２次側回路（20）の冷媒の凝縮によって低圧が生成する。そして、第１及び第２加熱熱交換器（HEX3a,HEX3b）の高圧と冷却熱交換器（HEX4）の低圧とを第１及び第２メインタンク（T1,T2）に供給し、上記実施形態１の２次側回路（20）と同様に動作して、各メインタンク（T1,T2）での液冷媒の押し出しと回収とを行う。一方、主回路（21）では、上記実施形態１の冷房運転時とほぼ同様に冷媒が循環し、室内の冷房を行う。即ち、室内熱交換器（HEX1）で蒸発した冷媒が上記第１〜第３主熱交換器（HEX2a〜HEX2c）に分流して流れ、各主熱交換器（HEX2a〜HEX2c）において上記第１〜第３回路（10a〜10c）の冷媒と熱交換を行って凝縮する点のみが上記実施形態１における動作と異なる。
【００７６】
次に、暖房運転時における運転動作について説明する。
【００７７】
この運転時において、上記第１回路（10a）では、第１四路切換弁（12a）が図５に破線で示すように切り換えられ、第２膨張弁（EV-2）が全開に調整され、第１膨張弁（EV-1）及び第３膨張弁（EV-3）が所定開度に調整され、電磁弁（SV）が開放される。
【００７８】
この状態において、図７に実線の矢印で示すように、第１回路（10a）内を冷媒が循環する。即ち、第１圧縮機（11a）から吐出された高圧のガス冷媒は分流されて、一部は第１主熱交換器（HEX2a）へ向かって流れ、残りは第１加熱熱交換器（HEX3a）へ向かって流れる。第１主熱交換器（HEX2a）へ向かう高圧のガス冷媒は、第１四路切換弁（12a）を通って第１主熱交換器（HEX2a）へ流れ、第１主熱交換器（HEX2a）で２次側回路（20）の冷媒と熱交換して凝縮して高圧の液冷媒となる。その際、第１回路（10a）において温熱が生成し、該温熱が２次側回路（20）の冷媒に供給される。一方、第１加熱熱交換器（HEX3a）へ向かう高圧のガス冷媒は、第１分岐配管（1）を通って第１加熱熱交換器（HEX3a）へ流れ、第１加熱熱交換器（HEX3a）で２次側回路（20）の液冷媒と熱交換して凝縮し、該２次側回路（20）の液冷媒を蒸発させる。該第１主熱交換器（HEX2a）及び第１加熱熱交換器（HEX3a）で凝縮して高圧の液冷媒となった冷媒は、一旦合流して第２分岐配管（2）を流れた後に再び分流されて、一部は第１室外熱交換器（HEX5a）へ向かって流れ、残りは冷却熱交換器（HEX4）へ向かって流れる。第１室外熱交換器（HEX5a）へ向かう高圧の液冷媒は、第１膨張弁（EV-1）で減圧されて低圧の液冷媒となり、その後、主配管（5a）を通って第１室外熱交換器（HEX5a）へ流れ、第１室外熱交換器（HEX5a）において外気と熱交換して蒸発する。一方、冷却熱交換器（HEX4）へ向かう高圧の液冷媒は、第２分岐配管（2）を流れ、第３膨張弁（EV-3）で減圧されて低圧の液冷媒となり、その後、冷却熱交換器（HEX4）において２次側回路（20）のガス冷媒と熱交換して蒸発し、該２次側回路（20）のガス冷媒を凝縮させる。該第１室外熱交換器（HEX5a）及び冷却熱交換器（HEX4）で蒸発した第１回路（10a）の冷媒は、合流した後に第１圧縮機（11a）に吸入され、この循環を繰り返す。
【００７９】
上記第２回路（10b）では、第２四路切換弁（12b）が図５に破線で示すように切り換えられ、第４膨張弁（EV-4）が全開に調整され、第５膨張弁（EV-5）が所定開度に調整される。
【００８０】
この状態において、図７に実線の矢印で示すように、第２回路（10b）内を冷媒が循環する。即ち、第２圧縮機（11b）から吐出された高圧のガス冷媒は、第２四路切換弁（12b）を通って第２主熱交換器（HEX2b）へ流れ、第２主熱交換器（HEX2b）で２次側回路（20）の冷媒と熱交換して凝縮して高圧の液冷媒となる。その際、第２回路（10b）において温熱が生成し、該温熱が２次側回路（20）の冷媒に供給される。第２主熱交換器（HEX2b）で凝縮した高圧の液冷媒は、主配管２から第３分岐配管（3）へ流入し、第５膨張弁（EV-5）で減圧されて低圧の液冷媒となる。該低圧の液冷媒は、主配管（5b）を通って第２室外熱交換器（HEX5b）へ流れ、第２室外熱交換器（HEX5b）において外気と熱交換して蒸発する。該第２室外熱交換器（HEX5b）で蒸発した第２回路（10b）のガス冷媒は、第２四路切換弁（12b）を通って第２圧縮機（11b）に吸入され、この循環を繰り返す。この運転状態においては、第２加熱熱交換器（HEX3b）へは第２回路（10b）の冷媒は供給されない。
【００８１】
上記第３回路（10c）では、第３四路切換弁（12c）が図５に破線で示すように切り換えられ、第６膨張弁（EV-6）が所定開度に調整される。
【００８２】
この状態において、図７に実線の矢印で示すように、第３回路（10c）内を冷媒が循環する。即ち、第３圧縮機（11c）から吐出された高圧のガス冷媒は、第３四路切換弁（12c）を通って第３主熱交換器（HEX2c）へ流れ、第３主熱交換器（HEX2c）で２次側回路（20）の冷媒と熱交換して凝縮して高圧の液冷媒となる。その際、第３回路（10c）において温熱が生成し、該温熱が２次側回路（20）の冷媒に供給される。第３主熱交換器（HEX2c）で凝縮して高圧の液冷媒となった冷媒は、第６膨張弁（EV-6）で減圧されて低圧の液冷媒となる。該低圧の液冷媒は、主配管（5c）を通って第３室外熱交換器（HEX5c）へ流れ、第３室外熱交換器（HEX5c）において外気と熱交換して蒸発する。該第３室外熱交換器（HEX5c）で蒸発した第３回路（10c）のガス冷媒は、第３四路切換弁（12c）を通って第３圧縮機（11c）に吸入され、この循環を繰り返す。
【００８３】
また、上記２次側回路（20）において、搬送回路（30）では、第１加熱熱交換器（HEX3a）における２次側回路（20）の冷媒の蒸発によって高圧が生成し、冷却熱交換器（HEX4）における２次側回路（20）の冷媒の凝縮によって低圧が生成する。そして、第１及び第２加熱熱交換器（HEX3a,HEX3b）の高圧と冷却熱交換器（HEX4）の低圧とを第１及び第２メインタンク（T1,T2）に供給し、上記実施形態１の２次側回路（20）と同様に動作して、各メインタンク（T1,T2）での液冷媒の押し出しと回収とを行う。一方、主回路（21）では、上記実施形態１の暖房運転時とほぼ同様に冷媒が循環し、室内の暖房を行う。即ち、各メインタンク（T1,T2）から押し出された液冷媒が上記第１〜第３主熱交換器（HEX2a〜HEX2c）に分流して流れ、各主熱交換器（HEX2a〜HEX2c）において上記第１〜第３回路（10a〜10c）の冷媒と熱交換を行って蒸発する点のみが上記実施形態１における動作と異なる。
【００８４】
−実施形態２の効果−
本実施形態２によれば、上記実施形態１で得られる効果と同様の効果が得られる。つまり、第２加熱熱交換器（HEX3b）において充分な高圧を生成できない運転状態においては、２次側回路（20）の冷媒を確実に循環させることができない。これに対して、本実施形態の１次側回路（10）は、第１回路（10a）の電磁弁（SV）を開放して、第１加熱熱交換器（HEX3a）へ第１回路（10a）の高圧のガス冷媒を供給することができる。これによって、上述の運転状態においても第１加熱熱交換器（HEX3a）で高圧を生成することができ、該高圧を用いて２次側回路（20）の冷媒を循環させることができる。この結果、運転状態に拘わらず、２次側回路（20）における冷媒の循環を充分に確保することができ、１次側回路（10）の温熱又は冷熱を室内熱交換器（HEX1）へ搬送することにより、空調能力を常に確保することができる。
【図面の簡単な説明】
【図１】実施形態１に係る空気調和装置の冷媒配管系統図である。
【図２】実施形態１に係る空気調和装置の冷房運転時において、１次側回路の高圧の液冷媒を加熱熱交換器に供給する運転時の冷媒循環動作を示す図である。
【図３】実施形態１に係る空気調和装置の冷房運転時において、１次側回路の高圧のガス冷媒を加熱熱交換器に供給する運転時の冷媒循環動作を示す図である。
【図４】実施形態１に係る空気調和装置の暖房運転時の冷媒循環動作を示す図である。
【図５】実施形態２に係る空気調和装置の冷媒配管系統図である。
【図６】実施形態２に係る空気調和装置の冷房運転時の冷媒循環動作を示す図である。
【図７】実施形態２に係る空気調和装置の暖房運転時の冷媒循環動作を示す図である。
【符号の説明】
（10）１次側回路（熱源側冷媒回路）
（11）圧縮機
（11a〜11c）第１〜第３圧縮機
（20）２次側回路（利用側冷媒回路）
（30）搬送回路（搬送手段）
（HEX1）室内熱交換器（利用側熱交換器）
（HEX2）主熱交換器
（HEX3）加熱熱交換器（加圧手段）
（HEX3a,HEX3b）第１，第２加熱熱交換器（加圧手段）
（HEX4）冷却熱交換器（減圧手段）
（HEX5）室外熱交換器
（T1）第１メインタンク
（T2）第２メインタンク[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a refrigeration apparatus including a primary side circuit that is a heat source and a secondary side circuit that circulates a refrigerant without using a pump and conveys the heat or cold of the heat source. It is concerned.
[0002]
[Prior art]
  2. Description of the Related Art Conventionally, a refrigeration apparatus includes a primary circuit that is a heat source and a secondary circuit that circulates refrigerant without using a pump and conveys the heat or cold of the heat source. What is comprised so that it may convey and utilize for the utilization side heat exchanger of a secondary side circuit is known.
[0003]
  In this type of refrigeration apparatus, the primary side circuit is a heat source side refrigerant circuit that includes a compressor and constitutes a vapor compression refrigeration cycle, while the secondary side circuit is disclosed in Japanese Patent Laid-Open No. 9-178217. There is a usage-side refrigerant circuit composed of a heat transfer device as described above, which is configured as an air-conditioning device that transfers warm or cold generated by a heat source to a use-side heat exchanger for air conditioning in a room.
[0004]
  Specifically, the primary circuit is provided with a main heat exchanger that supplies hot or cold heat to the refrigerant in the secondary circuit. In the main heat exchanger, the primary side refrigerant in the primary side circuit and the secondary side refrigerant in the secondary side circuit exchange heat, and the secondary side refrigerant condenses or evaporates to warm the primary side refrigerant. Or supply cold heat.
[0005]
  On the other hand, the secondary circuit is provided with a pair of tanks in which liquid refrigerant is stored, a driving heating heat exchanger, and a driving cooling heat exchanger. During the cooling operation in which cold heat is generated in the primary circuit, the high-temperature liquid refrigerant in the primary circuit is supplied to the heating heat exchanger, and heat exchange is performed between the high-pressure liquid refrigerant and the liquid refrigerant in the secondary circuit. Then, the secondary refrigerant is heated and evaporated to generate a high pressure in the secondary circuit. Further, during the heating operation in which the primary circuit generates heat, the high-pressure gas refrigerant in the primary circuit is supplied to the heating heat exchanger, and the high-pressure gas refrigerant and the liquid refrigerant in the secondary circuit are heated. The secondary side refrigerant evaporates and generates a high pressure in the secondary side circuit. Regardless of the operating state, the cooling heat exchanger is always supplied with the low-pressure liquid refrigerant in the primary circuit, and heat exchange occurs between the low-pressure liquid refrigerant and the gas refrigerant in the secondary circuit. Is cooled and condensed to generate a low pressure in the secondary circuit. By supplying this high pressure to one tank and simultaneously supplying the low pressure to the other tank, the liquid refrigerant is pushed out from one tank and the liquid refrigerant is recovered into the other tank at the same time. The refrigerant circulation operation in the secondary circuit is obtained.
[0006]
  As described above, the refrigerant circulates in the secondary circuit, and the hot or cold heat of the primary circuit is conveyed to the use-side heat exchanger. The use-side heat exchanger receives heat to perform heat radiation operation to heat the room, and receives cold to perform heat absorption operation to cool the room.
[0007]
[Problems to be solved by the invention]
  As described above, the conventional refrigeration apparatus heats the liquid refrigerant in the secondary circuit with the high-pressure liquid refrigerant in the primary circuit in the heating heat exchanger during the cooling operation in which cold heat is generated in the primary circuit. Evaporation generates high pressure. On the other hand, depending on the operation state, the temperature of the high-pressure liquid refrigerant in the primary circuit may be lower than a predetermined value. In this case, a predetermined high pressure cannot be generated by the heating heat exchanger, and the circulation amount of the refrigerant in the secondary circuit is reduced, so that there is a problem that the refrigeration apparatus cannot exhibit sufficient capacity. .
[0008]
  Specifically, in the primary circuit, the high-pressure gas refrigerant discharged from the compressor may be condensed by heat exchange with the outside air, and the condensed refrigerant becomes the high-pressure liquid refrigerant. In this case, when the outside air temperature is low, it is further cooled after being condensed, and the temperature of the high-pressure liquid refrigerant falls below a predetermined value. In other words, since the secondary refrigerant is evaporated by the high-pressure liquid refrigerant in the primary circuit that has become lower than the predetermined temperature, the evaporation amount of the secondary refrigerant in the driving heating heat exchanger is reduced, and the high pressure is reduced. In some cases, it could not be produced sufficiently.
[0009]
  The present invention has been made in view of the above points, and the object of the present invention is to ensure the amount of refrigerant circulating in the use-side refrigerant circuit, which is the secondary circuit, in any operating state, and always exhibit a predetermined capacity. There is to do.
[0010]
[Means for Solving the Problems]
  The present invention provides a heat source side refrigerant circuit for the pressurizing means (HEX3) of the conveying means (30) during the heat absorbing operation of the use side heat exchanger (HEX1) that generates cold in the heat source side refrigerant circuit (10). The high-pressure gas refrigerant of (10) can be supplied.
[0011]
  Specifically, the present invention tookFirst and second solving meansCirculates the refrigerant by the heat source side refrigerant circuit (10) for generating the heat or cold and the conveying means (30), and the heat or cold of the heat source side refrigerant circuit (10) is transferred to the use side heat exchanger (HEX1) It is premised on a refrigeration apparatus provided with a use side refrigerant circuit (20) that is transported and causes the use side heat exchanger (HEX1) to perform an endothermic operation or a heat release operation. And the said conveying means (30) is equipped with the pressurization means (HEX3) which produces | generates a high pressure, and the pressure reduction means (HEX4) which produces | generates a low pressure, The high pressure and pressure reduction means (HEX3) produced | generated by this pressurization means (HEX3) ( HEX4) is configured to apply a circulation driving force to the refrigerant in the use side refrigerant circuit (20) by the difference from the low pressure generated in HEX4), and the pressurizing means (HEX3) is connected to the refrigerant in the heat source side refrigerant circuit (10). The liquid refrigerant in the use side refrigerant circuit (20) is heated and evaporated by heat exchange with the refrigerant to generate high pressure, and the heat source side refrigerant circuit (10) is connected to the compressor (11 The high-pressure liquid refrigerant that flows out of the condenser of the heat source side refrigerant circuit (10) during the heat absorption operation of the use side heat exchanger (HEX1) And the high-pressure gas refrigerant discharged from the compressor (11) can be supplied to the pressurizing means (HEX3). It is intended to.
[0012]
  And,The firstThe solution isIn addition to the configuration described aboveThe heat source side refrigerant circuit (10) is formed by one closed circuit including the compressor (11), and the refrigerant supplied to the pressurizing means (HEX3) can be switched between the high-pressure liquid refrigerant and the high-pressure gas refrigerant. It constitutes.
[0013]
  Also,Second aboveThe solution isIn addition to the configuration described aboveThe heat source side refrigerant circuit (10) is constituted by a plurality of closed circuits each having a compressor (11a to 11c),Heat source side refrigerant circuit ( Ten Multiple closed circuits ( 10a, 10b, 10c ) Some of themClosed circuit( 10b )But,The high pressure liquid refrigerant is added to the pressurizing means (HEX3b).OnlySupplyLikeConfigured,remainingClosed circuit( 10a At least one ofBut,The above high-pressure gas refrigerant in the pressurizing means (HEX3a)Only supply state and pressurizing means ( HEX3a ) Is switched to a state in which neither the high-pressure liquid refrigerant nor the high-pressure gas refrigerant is supplied.It is configured to be possible.
[0014]
      -Action-
  the aboveFirst and second solving meansThen, in the heat source side refrigerant circuit (10), the high-pressure gas refrigerant discharged from the compressor (11) condenses to become a high-pressure liquid refrigerant, and the high-pressure liquid refrigerant evaporates after being depressurized, and the evaporated gas refrigerant becomes again It is sucked into the compressor (11) and repeats this circulation. The heat source side refrigerant circuit (10) is configured to supply the use-side refrigerant circuit (20) with the heat generated when the refrigerant condenses, and to use the cold heat generated when the refrigerant evaporates on the use-side refrigerant circuit (20). The operation to be supplied to is switched. Further, the heat source side refrigerant circuit (10) supplies the refrigerant to the pressurizing means (HEX3) of the usage side refrigerant circuit (20) in order to heat the refrigerant of the usage side refrigerant circuit (20). At this time, the heat source side refrigerant circuit (10) is configured to supply the high pressure gas refrigerant to the pressurizing means (HEX3) during the heat absorption operation of the usage side heat exchanger (HEX1) for supplying cold to the usage side refrigerant circuit (20). And a high-pressure liquid refrigerant can be supplied.
[0015]
  On the other hand, in the use side refrigerant circuit (20), the pressurizing means (HEX3) generates a high pressure at the same time, and the pressure reducing means (HEX4) generates a low pressure, and the circulation driving force is given by the pressure difference between the high pressure and the low pressure. The refrigerant circulates. With the refrigerant circulating in the circuit, the heat or cold generated in the heat source side refrigerant circuit (10) is conveyed to the use side heat exchanger (HEX1). The use-side heat exchanger (HEX1) performs a heat radiating operation for receiving the warm heat and releasing the heat to the outside, and a heat absorbing operation for receiving the cold and absorbing the heat from the outside. At that time, the pressurizing means (HEX3) receives the supply of the refrigerant from the heat source side refrigerant circuit (10), and exchanges heat between the refrigerant and the liquid refrigerant in the use side refrigerant circuit (20). As a result, the refrigerant in the use side refrigerant circuit (20) is heated and evaporated, and high pressure is generated in the pressurizing means (HEX3).
[0016]
  And,the aboveFirstIn this solution, since the heat source side refrigerant circuit (10) is constituted by one closed circuit, among the refrigerant circulating in the closed circuit, the high-pressure liquid refrigerant and the high-pressure gas refrigerant are switched to each other and pressurized. Supplied to the means (HEX3).
[0017]
  Also, aboveSecondIn this solution, the heat source side refrigerant circuit (10) is constituted by a plurality of closed circuits.The theseMultiple closed circuitsThen, some of themClosed circuit( 10b )High pressure liquid refrigerantOnlyIs supplied to the pressurizing means (HEX3a, HEX3b)remainingClosed circuit( 10a ) At least one of the pressurizing means ( HEX3a ) Is supplied with only high-pressure gas refrigerant, and pressurizing means ( HEX3a ) Is switched to a state in which neither the high-pressure liquid refrigerant nor the high-pressure gas refrigerant is supplied.
[0018]
【The invention's effect】
  As described above, according to the present solving means, the high pressure gas refrigerant of the heat source side refrigerant circuit (10) can be supplied to the pressurizing means (HEX3), so that the refrigerant circulation of the use side refrigerant circuit (20) is always performed. The amount can be kept at a predetermined amount. That is, the high-pressure gas refrigerant is a gas refrigerant discharged from the compressor (11), and in any operating state, the high-pressure gas refrigerant is in a high temperature state sufficient to evaporate the liquid refrigerant in the use-side refrigerant circuit (20). It has become. Therefore, by supplying the high-pressure gas refrigerant to the pressurizing means (HEX3), the liquid refrigerant in the use-side refrigerant circuit (20) can be reliably heated and evaporated, and sufficient high pressure can be generated. . As a result, the refrigerant circulation in the use side refrigerant circuit (20) can be sufficiently ensured regardless of the operating state, and the heat or cold of the heat source side refrigerant circuit (10) is transferred to the use side heat exchanger (HEX1). It can be transported to ensure driving capacity at all times.
[0019]
  In particular, in the pressurizing means (HEX3), when sufficient high pressure can be generated by the high-pressure liquid refrigerant in the heat source side refrigerant circuit (10), an operation for supplying the high-pressure liquid refrigerant to the pressurizing means (HEX3) is performed. Can do. That is, the COP (coefficient of performance) of the refrigeration cycle in the heat source side refrigerant circuit (10) is higher than the operation of supplying the high pressure gas refrigerant in the heat source side refrigerant circuit (10) to the pressurizing means (HEX3). Therefore, the above-described solution means enables the operation of supplying the high pressure liquid refrigerant of the heat source side refrigerant circuit (10) to the pressurizing means (HEX3). As a result, the conventional operation of supplying the high-pressure liquid refrigerant to the pressurizing means (HEX3) can be performed to maintain the COP of the heat source side refrigerant circuit (10) high, and in the past, sufficient capacity cannot be exhibited. Even in the operating state, the driving capability can always be ensured by supplying the high-pressure gas refrigerant to the pressurizing means (HEX3).
[0020]
  In the heat source side refrigerant circuit (10), the COP is higher when the high pressure liquid refrigerant is supplied to the pressurizing means (HEX3) than when the high pressure gas refrigerant is supplied to the pressurizing means (HEX3). Depending on the reason. In the operation of supplying the high pressure liquid refrigerant to the pressurizing means (HEX3), the liquid refrigerant in the use side refrigerant circuit (20) is heated by the high pressure liquid refrigerant obtained by condensing the high pressure gas refrigerant. Therefore, the amount of heat required for this heating is excessively dissipated from the heat source side refrigerant circuit (10), and the high pressure gas refrigerant is condensed compared to the case where the high pressure gas refrigerant is supplied to the pressurizing means (HEX3). The subcool of the high-pressure liquid refrigerant increases. Then, since the liquid refrigerant with reduced enthalpy is decompressed and then evaporated to generate cold heat, the amount of heat absorbed during the evaporation of the liquid refrigerant increases. That is, the amount of cold generated by the evaporation of the liquid refrigerant increases, and as a result, the COP in the heat source side refrigerant circuit (10) increases.
[0021]
DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1
  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. As shown in FIG. 1, the refrigeration apparatus of the present embodiment includes a heat source side refrigerant circuit (10) that generates hot or cold heat, and a transfer circuit (30) that is a transfer means, and includes a heat source side refrigerant circuit (10). A utilization side refrigerant circuit (20) that conveys and uses hot or cold heat to the indoor heat exchanger (HEX1). And the said freezing apparatus is comprised by the air conditioning apparatus which performs indoor air conditioning by the thermal radiation operation | movement or heat absorption operation | movement of the indoor heat exchanger (HEX1) of a utilization side refrigerant circuit (20). Hereinafter, the heat source side refrigerant circuit (10) is referred to as a primary side circuit (10), and the use side refrigerant circuit (20) is referred to as a secondary side circuit (20).
[0022]
  The secondary circuit (20) is connected to a main circuit (21) including a main heat exchanger (HEX2) and a plurality of indoor units (22) via a secondary four-way switching valve (23). It is formed by connecting the transport circuit (30). The indoor unit (22) is configured by connecting an indoor heat exchanger (HEX1), which is a use-side heat exchanger, and an indoor electric valve (EV) in series with a refrigerant pipe. One end of each indoor unit (22) on the indoor heat exchanger (HEX1) side is connected to the upper end of the main heat exchanger (HEX2) via the main gas pipe (24), and each indoor unit One end of the (22) indoor electric valve (EV) side is connected to the secondary side four-way selector valve (23) via the main liquid pipe (25). The lower end of the main heat exchanger (HEX2) is connected to the secondary side four-way switching valve (23) via the main liquid pipe (26). As described above, the main circuit (21) is formed.
[0023]
  The transport circuit (30) is filled with a refrigerant, and includes a heating heat exchanger (HEX3) as a pressurizing unit, a cooling heat exchanger (HEX4) as a depressurizing unit, and a first and a second that store liquid refrigerant A second main tank (T1, T2) and a sub tank (ST) are provided. The heating heat exchanger (HEX3) is supplied with the refrigerant of the primary side circuit (10), and exchanges heat between the primary side refrigerant and the liquid refrigerant of the secondary side circuit (20), thereby the secondary side refrigerant. Is heated and evaporated to generate high pressure. The cooling heat exchanger (HEX4) is supplied with the refrigerant in the primary circuit (10), exchanges heat between the primary refrigerant and the gas refrigerant in the secondary circuit (20), and then supplies the secondary refrigerant. Is cooled and condensed to generate a low pressure. The high pressure of the heating heat exchanger (HEX3) is supplied to one main tank (T1, T2) to push out the liquid refrigerant in the main tank (T1, T2) and at the same time, the cooling heat exchanger (HEX4) Low pressure is supplied to the other main tank (T1, T2) to recover the liquid refrigerant into the main tank (T1, T2). As described above, the conveyance circuit (30) is configured to apply a circulation driving force to the refrigerant of the secondary circuit (20).
[0024]
  Specifically, a gas recovery pipe (32) is connected to the upper end of the cooling heat exchanger (HEX4). This gas recovery pipe (32) is branched into three branch pipes (32a, 32b, 32c), and each branch pipe (32a-32c) is the upper end of each main tank (T1, T2) and sub tank (ST). Are connected individually. Each of the branch pipes (32a to 32c) is provided with first to third tank pressure reducing solenoid valves (SV-V1, SV-V2, SV-V3). A liquid supply pipe (33), which is a liquid pipe, is connected to the lower end of the cooling heat exchanger (HEX4). The liquid supply pipe (33) is branched into two branch pipes (33a, 33b), and each branch pipe (33a, 33b) is connected to the lower end of each main tank (T1, T2). These branch pipes (33a, 33b) are provided with check valves (CV-2) that allow only the recovery of the refrigerant to the main tanks (T1, T2).
[0025]
  On the other hand, a gas supply pipe (31) is connected to the upper end of the heating heat exchanger (HEX3). The gas supply pipe (31) is branched into three branch pipes (31a, 31b, 31c), and each branch pipe (31a-31c) is connected to the branch pipe (32a-32c) of the gas recovery pipe (32). It is connected. Thus, the branch pipes (31a to 31c) of the gas supply pipe (31) are individually connected to the upper ends of the main tanks (T1, T2) and the sub tanks (ST). Each of the branch pipes (31a to 31c) is provided with first to third tank pressurizing solenoid valves (SV-P1, SV-P2, SV-P3). In addition, a liquid recovery pipe (34) is connected to the lower end of the heating heat exchanger (HEX3). The liquid recovery pipe (34) is connected to the lower end of the sub tank (ST). The liquid recovery pipe (34) is provided with a check valve (CV-1) that allows only refrigerant outflow from the sub tank (ST).
[0026]
  Each main tank (T1, T2) is installed at a position lower than the cooling heat exchanger (HEX4). The sub tank (ST) is installed at a position higher than the heating heat exchanger (HEX3).
[0027]
  Further, a recovery liquid pipe (38) and an extrusion liquid pipe (37) are connected to each main tank (T1, T2). The recovery liquid pipe (38) is branched into two branch pipes (38a, 38b), and each branch pipe (38a, 38b) is connected to the lower end of each main tank (T1, T2). Each of the branch pipes (38a, 38b) is provided with a check valve (CV-5) that allows only the refrigerant to flow into the main tanks (T1, T2). On the other hand, the extrusion liquid pipe (37) is branched into three branch pipes (37a, 37b, 37c), and the branch pipes (37a to 37c) are branched pipes (38a, 38b) of the recovery liquid pipe (38). ) And the liquid recovery pipe (34), thereby connecting to the lower ends of the main tanks (T1, T2) and the sub tanks (ST). Among these branch pipes (37a to 37c), the branch pipes (37a, 37b) connected to the main tanks (T1, T2) are reverse to allow only the refrigerant outflow from the lower ends of the main tanks (T1, T2). While the stop valve (CV-3) is provided, the branch pipe (37c) connected to the sub tank (ST) has a check valve (CV-4) that allows only the refrigerant to flow into the sub tank (ST). Is provided.
[0028]
  As described above, the transfer circuit (30) is configured, and the recovery liquid pipe (38) and the extrusion liquid pipe (37) of the transfer circuit (30) are connected to the secondary four-way switching valve (23). To the main liquid pipe (25, 26) of the main circuit (21). In the secondary circuit (20), the liquid refrigerant pushed out from one main tank (T1, T2) flows to the main circuit (21) through the extrusion liquid pipe (37), and the main circuit (21 ) Is circulated through the recovery liquid pipe (38) and then recovered to the other main tank (T1, T2). In addition, the refrigerant circulation direction can be reversed in the main circuit (21) by switching the secondary side four-way selector valve (23).
[0029]
  The primary circuit (10) includes a compressor (11), a primary four-way selector valve (12), an outdoor heat exchanger (HEX5), a first expansion valve (EV-1), and a main heat exchanger ( HEX2) is a closed circuit in which main pipes (5) are connected in order, and constitutes a vapor compression refrigeration cycle in which refrigerant circulates and generates hot or cold. The primary circuit (10) is connected to the heating heat exchanger (HEX3) and the cooling heat exchanger (HEX4) of the transport circuit (30), and refrigerant is supplied to these heat exchangers (HEX3, HEX4). It is configured to supply.
[0030]
  The heating heat exchanger (HEX3) is provided in the main pipe (5) between the outdoor heat exchanger (HEX5) and the first expansion valve (EV-1). Specifically, the upper end portion of the heating heat exchanger (HEX3) is connected to the outdoor heat exchanger (HEX5) via the main pipe (5), and the lower end portion is connected to the first expansion valve via the main pipe (5). (EV-1) connected. Also, a check valve that allows only the flow of refrigerant from the outdoor heat exchanger (HEX5) to the heating heat exchanger (HEX3) between the heating heat exchanger (HEX3) and the outdoor heat exchanger (HEX5). (CV-6) is provided.
[0031]
  The cooling heat exchanger (HEX4) is connected to the primary circuit (10) via the first branch pipe (1). Specifically, the upper end of the cooling heat exchanger (HEX4) is connected to the compressor (11) via a main pipe (5) between the compressor (11) and the primary side four-way switching valve (12). Connected to the suction side, the lower end is connected to the main pipe (5) between the heating heat exchanger (HEX3) and the first expansion valve (EV-1). A second expansion valve (EV-2) is provided between the lower end of the cooling heat exchanger (HEX4) of the first branch pipe (1) and the main pipe (5).
[0032]
  The primary circuit (10) is provided with a second branch pipe (2), a third branch pipe (3), and a fourth branch pipe (4). As a feature of the present invention, the primary circuit (10) is configured to be able to supply high-pressure liquid refrigerant and high-pressure gas refrigerant to the heating heat exchanger (HEX3) during the cooling operation.
[0033]
  The second branch pipe (2) has one end connected to the discharge side of the compressor (11) via the main pipe (5) between the compressor (11) and the primary four-way selector valve (12). The other end is connected between the heating heat exchanger (HEX3) and the check valve (CV-6). The second branch pipe (2) is provided with a first solenoid valve (SV-1). And it is comprised so that the discharge gas of the compressor (11) which is a high-pressure gas refrigerant may be supplied to a heating heat exchanger (HEX3).
[0034]
  One end of the third branch pipe (3) is connected between the check valve (CV-6) and the outdoor heat exchanger (HEX5), and the other end is connected to the heating heat exchanger (HEX3) and the first expansion valve. (EV-1) connected. The third branch pipe (3) is provided with a second solenoid valve (SV-2). And it is comprised so that a refrigerant | coolant can be flowed by bypassing a heating heat exchanger (HEX3) and a non-return valve (CV-6).
[0035]
  One end of the fourth branch pipe (4) is connected to the first branch pipe (1) between the second expansion valve (EV-2) and the main pipe (5), and the other end is a check valve (CV -6) and the outdoor heat exchanger (HEX5). The fourth branch pipe (4) is a check that allows only the third expansion valve (EV-3) and the refrigerant flow from the one end to the other end in order from the one end to the other end. And a valve (CV-7). And it is comprised so that a liquid refrigerant may distribute | circulate at the time of heating operation.
[0036]
      -Driving action-
  An operation operation during the cooling operation will be described.
[0037]
  First, the operation of the primary side circuit (10) will be described. During this operation, in the primary side circuit (10), the primary side four-way switching valve (12) is switched as shown by a solid line in FIG. 1, and the first expansion valve (EV-1) and the second expansion valve The valve (EV-2) is adjusted to a predetermined opening, and the third expansion valve (EV-3) is closed. When supplying high-pressure liquid refrigerant to the heating heat exchanger (HEX3), the first solenoid valve (SV-1) and the second solenoid valve (SV-2) are closed.
[0038]
  In this state, the refrigerant circulates in the primary circuit (10) as shown by the solid line arrow in FIG. That is, the high-pressure gas refrigerant discharged from the compressor (11) flows to the outdoor heat exchanger (HEX5) through the primary side four-way switching valve (12), and the outdoor heat exchanger (HEX5) Heat exchanges and condenses to form a high-pressure liquid refrigerant. This high-pressure liquid refrigerant flows to the heating heat exchanger (HEX3) through the main pipe (5), and exchanges heat with the liquid refrigerant in the secondary circuit (20) in the heating heat exchanger (HEX3). The liquid refrigerant in the secondary circuit (20) is evaporated. The high-pressure liquid refrigerant flowing out of the heating heat exchanger (HEX3) is divided and partly flows toward the main heat exchanger (HEX2), and the rest flows toward the cooling heat exchanger (HEX4). The high-pressure liquid refrigerant going to the main heat exchanger (HEX2) flows through the main pipe (5) and is depressurized by the first expansion valve (EV-1) to become a low-pressure liquid refrigerant, and then the main heat exchanger (HEX2 ) And evaporates by exchanging heat with the refrigerant in the secondary circuit (20). At that time, cold heat is generated in the primary circuit (10), and the cold heat is supplied to the refrigerant in the secondary circuit (20). On the other hand, the high-pressure liquid refrigerant going to the cooling heat exchanger (HEX4) flows through the first branch pipe (1) and is depressurized by the second expansion valve (EV-2) to become a low-pressure liquid refrigerant. The exchanger (HEX4) exchanges heat with the gas refrigerant in the secondary circuit (20) and evaporates to condense the gas refrigerant in the secondary circuit (20). The refrigerant in the primary circuit (10) evaporated in the main heat exchanger (HEX2) and the cooling heat exchanger (HEX4) joins and then is sucked into the compressor (11) and repeats this circulation.
[0039]
  Moreover, when supplying a high-pressure gas refrigerant to the heating heat exchanger (HEX3), the first solenoid valve (SV-1) and the second solenoid valve (SV-2) are opened in the above-described state.
[0040]
  In this state, the refrigerant circulates in the primary circuit (10) as shown by the solid line arrow in FIG. That is, the high-pressure gas refrigerant discharged from the compressor (11) is divided and partly flows toward the outdoor heat exchanger (HEX5), and the rest flows toward the heating heat exchanger (HEX3). The high-pressure gas refrigerant going to the outdoor heat exchanger (HEX5) flows through the main pipe (5), passes through the primary four-way selector valve (12), and flows to the outdoor heat exchanger (HEX5). (HEX5) exchanges heat with the outside air to condense into a high-pressure liquid refrigerant. This high-pressure liquid refrigerant flows through the main pipe (5) to the third branch pipe (3). On the other hand, the high-pressure gas refrigerant going to the heating heat exchanger (HEX3) flows to the heating heat exchanger (HEX3) through the second branch pipe (2), and the secondary side circuit (HEX3) The liquid refrigerant of 20) is heat-exchanged and condensed to evaporate the liquid refrigerant of the secondary circuit (20). The high-pressure liquid refrigerant condensed in the outdoor heat exchanger (HEX5) and heating heat exchanger (HEX3) is once merged and then diverted again, and partly flows toward the main heat exchanger (HEX2) and remains. Flows toward the cooling heat exchanger (HEX4). Thereafter, the divided high-pressure liquid refrigerant flows in the same manner as when the high-pressure liquid refrigerant is supplied to the above-described heating heat exchanger (HEX3). That is, the pressure is reduced by the first expansion valve (EV-1) and the second expansion valve (EV-2) respectively, evaporated by the main heat exchanger (HEX2) and the cooling heat exchanger (HEX4), and then merged with each other. Then, it is sucked into the compressor (11) and repeats this circulation.
[0041]
  As described above, the primary side circuit (10) generates high-pressure liquid refrigerant and high-pressure gas refrigerant by opening and closing operations of the first solenoid valve (SV-1) and the second solenoid valve (SV-2). Switch to supply to the heat exchanger (HEX3).
[0042]
  Next, the operation of the secondary side circuit (20) will be described. The explanation starts from the state that each solenoid valve (SV-P1, SV-V2, SV-P3) of the transfer circuit (30) is in the following state. The pressurization solenoid valve (SV-P1) of the first main tank (T1), the pressurization solenoid valve (SV-P3) of the sub tank (ST), and the decompression solenoid valve (SV-V2) of the second main tank (T2) It is open. On the other hand, the pressure solenoid valve (SV-P2) of the second main tank (T2), the pressure reducing solenoid valve (SV-V1) of the first main tank (T1), the pressure reducing solenoid valve (SV-V3) of the sub tank (ST) Is closed. Further, the secondary side four-way switching valve (23) is switched as shown by a solid line in FIG. 1, and the indoor motor-operated valve (EV) of each indoor unit (22) is adjusted to a predetermined opening.
[0043]
  In this state, in the heating heat exchanger (HEX3), the refrigerant in the primary circuit (10) and the liquid refrigerant in the secondary circuit (20) exchange heat, and the secondary refrigerant is heated and evaporated. This creates a high pressure. This high pressure is supplied to the first main tank (T1) through the branch pipe (31a) of the gas supply pipe (31), and the first main tank (T1) is pressurized. For this reason, the liquid refrigerant stored in the first main tank (T1) is pushed out of the first main tank (T1) as shown by the one-dot chain arrow in FIG. The liquid refrigerant extruded from the first main tank (T1) flows from the branch pipe (37a) of the extrusion liquid pipe (37) to the extrusion liquid pipe (37), and the secondary side four-way switching valve (23 ) To the main liquid pipe (25) of the main circuit (21).
[0044]
  On the other hand, in the cooling heat exchanger (HEX4), the refrigerant in the primary circuit (10) and the gas refrigerant in the secondary circuit (20) exchange heat, and the secondary refrigerant is cooled and condensed. Low pressure is generated. This low pressure is supplied to the second main tank (T2) through the branch pipe (32b) of the gas recovery pipe (32), and the second main tank (T2) is depressurized. For this reason, the liquid refrigerant of the main circuit (21) is recovered in the second main tank (T2). That is, as indicated by the one-dot chain line arrow in FIG. 2, the liquid refrigerant in the main liquid pipe (26) of the main pipe (5) is sucked, and the secondary side four-way switching valve (23) and the recovery liquid pipe (38 ) And flows in the branch pipe (38b) of the recovery liquid pipe (38) in order, and is recovered in the second main tank (T2).
[0045]
  In the main circuit (21) of the secondary side circuit (20), the liquid refrigerant is pushed out from the first main tank (T1) and the liquid refrigerant is collected into the second main tank (T2) as described above. The refrigerant circulates and cools the room by conveying the cold of the primary circuit (10) to the indoor heat exchanger (HEX1). Specifically, the liquid refrigerant pushed out from the first main tank (T1) and flowing into the main liquid pipe (25) is divided into the indoor units (22). In that case, the flow volume of the liquid refrigerant which flows into each indoor unit (22) is adjusted by adjusting the opening degree of each indoor motor operated valve (EV). The liquid refrigerant branched to each indoor unit (22) evaporates by exchanging heat with indoor air in each indoor heat exchanger (HEX1), and cools the indoor air to generate conditioned air. And this low-temperature conditioned air is used for indoor cooling. On the other hand, the refrigerant evaporated in each indoor heat exchanger (HEX1) joins and flows to the main heat exchanger (HEX2) through the main gas pipe (24). The gas refrigerant that has flowed to the main heat exchanger (HEX2) exchanges heat with the refrigerant in the primary circuit (10), and is cooled and condensed by the cold generated by the evaporation of the primary refrigerant. Becomes a refrigerant. The liquid refrigerant flows through the main liquid pipe (26), and is recovered through the recovery liquid pipe (38) to the second main tank (T2).
[0046]
  In the transfer circuit (30), the sub tank (ST) is pressure-equalized with the heating heat exchanger (HEX3). Therefore, as indicated by the one-dot chain line arrow in FIG. 2, the liquid refrigerant in the sub tank (ST) is supplied to the heating heat exchanger (HEX3) through the liquid recovery pipe (34). The supplied liquid refrigerant evaporates in the heating heat exchanger (HEX3) and contributes to pressurization in the first main tank (T1). After that, when most of the liquid refrigerant in the sub tank (ST) is supplied to the heating heat exchanger (HEX3), the pressurization solenoid valve (SV-P3) of the sub tank (ST) is closed and the sub tank (ST ) Pressure reducing solenoid valve (SV-V3) is opened. As a result, the pressure in the sub tank (ST) becomes low, and a part of the refrigerant flowing through the extrusion liquid pipe (37) is recovered as indicated by the broken arrow in FIG.
[0047]
  After performing such an operation for a predetermined time, the solenoid valves (SV-P1, SV-P2,...) Of the transport circuit (30) are switched. That is, the pressure solenoid valve (SV-P1) of the first main tank (T1), the pressure reducing solenoid valve (SV-V2) of the second main tank (T2), the pressure reducing solenoid valve (SV-V3) of the sub tank (ST) Close. Pressurize solenoid valve (SV-P2) of the second main tank (T2), decompression solenoid valve (SV-V1) of the first main tank (T1), pressurization solenoid valve (SV-P3) of the sub tank (ST) Open.
[0048]
  Thereby, the internal pressure of the first main tank (T1) becomes low, and conversely, the internal pressures of the second main tank (T2) and the sub tank (ST) become high. For this reason, the liquid refrigerant pushed out from the second main tank (T2) circulates in the same manner as described above and enters a refrigerant circulation state where the liquid refrigerant is collected in the first main tank (T1), and the liquid refrigerant in the sub tank (ST). Is supplied to the heating heat exchanger (HEX3). Also in this case, when most of the liquid refrigerant in the sub tank (ST) is supplied to the heating heat exchanger (HEX3), the pressurization solenoid valve (SV-P3) of the sub tank (ST) is closed, The decompression solenoid valve (SV-V3) of the sub tank (ST) is opened, and the refrigerant is collected into the sub tank (ST).
[0049]
  As described above, each solenoid valve (SV-P1, SV-P2,...) Performs a switching operation, and the refrigerant is pushed out from the first main tank (T1) and recovered into the second main tank (T2). The operation in which the refrigerant is pushed out from the second main tank (T2) and collected in the second main tank (T2) is alternately performed. Then, the refrigerant circulates in the main circuit (21) of the secondary side circuit (20) to cool the room.
[0050]
  Next, the operation operation at the time of heating operation will be described. During this operation, in the primary side circuit (10), the primary side four-way switching valve (12) is switched as shown by a broken line in FIG. 1, and the first expansion valve (EV-1) is adjusted to be fully open. Then, the second expansion valve (EV-2) and the third expansion valve (EV-3) are adjusted to a predetermined opening degree. Further, the first solenoid valve (SV-1) is opened, and the second solenoid valve (SV-2) is closed.
[0051]
  In this state, the refrigerant circulates in the primary circuit (10) as shown by the solid line arrow in FIG. That is, the high-pressure gas refrigerant discharged from the compressor (11) is divided and partly flows toward the main heat exchanger (HEX2), and the rest flows toward the heating heat exchanger (HEX3). The high-pressure gas refrigerant going to the main heat exchanger (HEX2) flows to the main heat exchanger (HEX2) through the primary four-way selector valve (12), and the secondary side circuit in the main heat exchanger (HEX2) Heat exchange with the refrigerant of (20) condenses to become a high-pressure liquid refrigerant. At that time, warm heat is generated in the primary circuit (10), and the warm heat is supplied to the refrigerant in the secondary circuit (20). On the other hand, the high-pressure gas refrigerant going to the heating heat exchanger (HEX3) flows to the heating heat exchanger (HEX3) through the second branch pipe (2), and the secondary side circuit (HEX3) The liquid refrigerant of 20) is heat-exchanged and condensed to evaporate the liquid refrigerant of the secondary circuit (20). The refrigerant that has condensed in the main heat exchanger (HEX2) and the heating heat exchanger (HEX3) to become a high-pressure liquid refrigerant once merged and flows again through the first branch pipe (1). Some flow toward the outdoor heat exchanger (HEX5), and the rest flows toward the cooling heat exchanger (HEX4). The high-pressure liquid refrigerant going to the outdoor heat exchanger (HEX5) flows through the fourth branch pipe (4) and is decompressed by the third expansion valve (EV-3) to become a low-pressure liquid refrigerant, and then the main pipe (5 ) To the outdoor heat exchanger (HEX5) and evaporates by exchanging heat with the outside air in the outdoor heat exchanger (HEX5). On the other hand, the high-pressure liquid refrigerant going to the cooling heat exchanger (HEX4) is depressurized by the second expansion valve (EV-2) to become a low-pressure liquid refrigerant, and then the secondary circuit in the cooling heat exchanger (HEX4). Heat exchange with the gas refrigerant of (20) evaporates to condense the gas refrigerant of the secondary circuit (20). The refrigerant in the primary circuit (10) evaporated in the outdoor heat exchanger (HEX5) and the cooling heat exchanger (HEX4) joins and then is sucked into the compressor (11) and repeats this circulation.
[0052]
  Further, in the secondary side circuit (20), the high pressure of the heating heat exchanger (HEX3) and the low pressure of the cooling heat exchanger (HEX4) are reduced in the transfer circuit (30) of the secondary side circuit (20). The liquid refrigerant is supplied to the first and second main tanks (T1, T2) and operates in the same manner as in the cooling operation described above, and the liquid refrigerant is pushed out and collected in each main tank (T1, T2).
[0053]
  In the main circuit (21) of the secondary side circuit (20), the refrigerant circulates by pushing out and collecting the liquid refrigerant in each main tank (T1, T2), and the temperature of the primary side circuit (10) is It is transported to the heat exchanger (HEX1) for indoor heating. The liquid refrigerant flowing from the liquid pipe for extrusion (37) of the transfer circuit (30) to the main circuit (21) passes through the secondary side four-way selector valve (23) and the main liquid pipe (26) in this order, and the main heat exchange. Flows to the vessel (HEX2). The liquid refrigerant that has flowed to the main heat exchanger (HEX2) exchanges heat with the refrigerant in the primary circuit (10), and is heated and evaporated by the heat generated by the condensation of the primary refrigerant. The gas refrigerant evaporated in the main heat exchanger (HEX2) flows through the main gas pipe (24) and is divided into each indoor unit (22). At that time, the flow rate of the gas refrigerant flowing to each indoor unit (22) is adjusted by adjusting the opening degree of each indoor motor operated valve (EV). The gas refrigerant branched to each indoor unit (22) condenses by exchanging heat with indoor air in each indoor heat exchanger (HEX1), and heats indoor air to generate conditioned air. This high-temperature conditioned air is used for indoor heating. On the other hand, the refrigerant condensed in each indoor heat exchanger (HEX1) joins and passes through the main liquid pipe (25) and the secondary side four-way switching valve (23) in order, and the recovery liquid pipe of the transfer circuit (30) (38) As described above, the refrigerant circulates in the main circuit (21) of the secondary circuit (20), and the room is heated.
[0054]
      -Effect of Embodiment 1-
  According to the first embodiment, even in an operation state in which the temperature of the high-pressure liquid refrigerant in the primary circuit (10) is lower than a predetermined value, the heating circuit (HEX3) is provided with the primary circuit (10). The high-pressure gas refrigerant can be supplied. For example, a cooling operation at a low outside air temperature can be considered as the above operating state. That is, the high-pressure gas refrigerant discharged from the compressor (11) is condensed by heat exchange with the outside air in the outdoor heat exchanger (HEX5) and becomes high-pressure liquid refrigerant. Therefore, when the outside air temperature is low, the condensed refrigerant is further cooled by the outside air, and the temperature of the high-pressure liquid refrigerant is lowered. On the other hand, the high-pressure gas refrigerant discharged from the compressor (11) is in a high temperature state sufficient to evaporate the liquid refrigerant in the secondary side circuit (20) even in the above-described operation state. For this reason, by supplying the high-pressure gas refrigerant to the heating heat exchanger (HEX3), the liquid refrigerant in the secondary circuit (20) can be reliably heated and evaporated, and a sufficiently high pressure is generated. be able to. As a result, the refrigerant circulation in the secondary circuit (20) can be sufficiently ensured regardless of the operating state, and the heat or cold of the primary circuit (10) is transferred to the indoor heat exchanger (HEX1). By doing so, it is possible to always ensure the air conditioning capability.
[0055]
  In particular, in the heating heat exchanger (HEX3), when sufficient high pressure can be generated by the high-pressure liquid refrigerant in the primary circuit (10), the high-pressure liquid refrigerant is supplied to the heating heat exchanger (HEX3). You can drive. That is, the COP (coefficient of performance) of the refrigeration cycle in the primary side circuit (10) is higher than the operation of supplying the high-pressure gas refrigerant in the primary side circuit (10) to the heating heat exchanger (HEX3). Therefore, this embodiment also enables an operation of supplying the high-pressure liquid refrigerant of the primary side circuit (10) to the heating heat exchanger (HEX3). As a result, the COP of the primary circuit (10) can be kept high by performing the operation of supplying the conventional high-pressure liquid refrigerant to the heating heat exchanger (HEX3), and at the same time, it exhibits sufficient capacity. Even in an operation state that could not be performed, for example, in a cooling operation at a low outside air temperature, it is possible to always ensure air conditioning capability by supplying a high-pressure gas refrigerant to the heating heat exchanger (HEX3).
[0056]
  In the primary circuit (10), the COP is higher when the high-pressure liquid refrigerant is supplied to the heating heat exchanger (HEX3) than when the high-pressure gas refrigerant is supplied to the heating heat exchanger (HEX3). The reason is as follows. In the operation of supplying the high-pressure liquid refrigerant to the heating heat exchanger (HEX3), the liquid refrigerant in the secondary circuit (20) is heated by the high-pressure liquid refrigerant obtained by condensing the high-pressure gas refrigerant. Therefore, the amount of heat required for this heating is dissipated from the primary circuit (10), and the high-pressure gas refrigerant is condensed compared to the case of supplying high-pressure gas refrigerant to the heating heat exchanger (HEX3). The subcool of the high-pressure liquid refrigerant thus formed increases. Then, since the liquid refrigerant with reduced enthalpy is decompressed and then evaporated to generate cold heat, the amount of heat absorbed during the evaporation of the liquid refrigerant increases. That is, the amount of cold heat generated by the evaporation of the liquid refrigerant increases, and as a result, the COP in the primary circuit (10) increases.
[0057]
Second Embodiment of the Invention
  In the second embodiment of the present invention, the first circuit (10a), the second circuit, as shown in FIG. The primary side circuit (10) is constituted by three closed circuits of (10b) and the third circuit (10c). Each of the first to third circuits (10a to 10c) includes a compressor (11a to 11c), and constitutes a vapor compression refrigeration cycle in which a refrigerant circulates to generate hot or cold.
[0058]
  The secondary side circuit (20) is configured in substantially the same manner as the secondary side circuit (20) of the first embodiment, but with the primary side circuit (10) configured by three closed circuits, the following is performed. This is different from that of the first embodiment. First, the main circuit (21) of the secondary circuit (20) has three main heat exchangers (HEX2a), a second main heat exchanger (HEX2b), and a third main heat exchanger (HEX2c). A main heat exchanger is provided. The first to third main heat exchangers (HEX5a to HEX5c) are connected in parallel to each other, and the upper ends of the main heat exchangers (HEX5a to HEX5c) are connected to the main gas pipe (24) of the main circuit (21). The lower ends are connected to the main liquid pipe (26), respectively. The transport circuit (30) of the secondary circuit (20) is provided with a first heating heat exchanger (HEX3a) and a second heating heat exchanger (HEX3b). In the first and second heating heat exchangers (HEX3a, HEX3b), the upper end of each heating heat exchanger (HEX3a, HEX3b) is the gas supply pipe (31) of the transfer circuit (30), and the lower end is liquid recovery. Each is connected to a pipe (34) and constitutes a pressurizing means. Other configurations are the same as those of the secondary circuit (20) of the first embodiment.
[0059]
  The first circuit (10a) constituting the primary side circuit (10) includes a first compressor (11a), a first four-way switching valve (12a), a first outdoor heat exchanger (HEX5a), and a first expansion. This is a closed circuit in which a valve (EV-1), a second expansion valve (EV-2), and a first main heat exchanger (HEX2a) are connected in order by a main pipe (5a). The first circuit (10a) is connected to the first heating heat exchanger (HEX3a) and the cooling heat exchanger (HEX4) of the transport circuit (30), and refrigerant is supplied to these heat exchangers (HEX3a, HEX4). Is configured to supply.
[0060]
  The first heating heat exchanger (HEX3a) is connected to the heat source side refrigerant circuit (10) via the first branch pipe (1). Specifically, the upper end of the first heating heat exchanger (HEX3a) is compressed through the main pipe (5a) between the first compressor (11a) and the first four-way switching valve (12a). Connected to the discharge side of the machine (11a), the lower end is connected to the main pipe (5a) between the first expansion valve (EV-1) and the second expansion valve (EV-2). An electromagnetic valve (SV) is provided between the lower end of the first heating heat exchanger (HEX3a) in the first branch pipe (1) and the main pipe. As a feature of the present invention, the first heating heat exchanger (HEX3a) can be supplied with the high-pressure gas refrigerant discharged from the first compressor (11a) through the first branch pipe (1). Has been.
[0061]
  The cooling heat exchanger (HEX4) is connected to the first circuit (10a) via the second branch pipe (2). Specifically, the upper end of the cooling heat exchanger (HEX4) is connected to the intake side of the compressor via a main pipe between the compressor and the primary four-way selector valve (12), and the lower end is The main pipe (5a) is connected between the first expansion valve (EV-1) and the second expansion valve (EV-2). A third expansion valve (EV-3) is provided between the lower end of the cooling heat exchanger (HEX4) of the second branch pipe (2) and the main pipe.
[0062]
  The second circuit (10b) constituting the primary side circuit (10) includes a second compressor (11b), a second four-way switching valve (12b), a second outdoor heat exchanger (HEX5b), and a fourth expansion. This is a closed circuit in which a valve (EV-4) and a second main heat exchanger (HEX2b) are sequentially connected by a main pipe (5b). The second circuit (10b) is connected to the second heating heat exchanger (HEX3b) of the transport circuit (30), and is configured to supply a refrigerant to the heat exchanger (HEX3b).
[0063]
  The second heating heat exchanger (HEX3b) is provided in the main pipe between the second outdoor heat exchanger (HEX5b) and the fourth expansion valve (EV-4). Specifically, the upper end of the second heating heat exchanger (HEX3b) is connected to the second outdoor heat exchanger (HEX5b) via the main pipe (5b), and the lower end is connected to the main pipe (5b). It is connected to the fourth expansion valve (EV-4). In addition, the refrigerant flowing from the second heating heat exchanger (HEX3b) to the fourth expansion valve (EV-4) is interposed between the second heating heat exchanger (HEX3b) and the fourth expansion valve (EV-4). There is a check valve (CV-6) that allows only flow. The second heating heat exchanger (HEX3b) is configured to be able to supply a high-pressure liquid refrigerant.
[0064]
  The second circuit (10b) is provided with a third branch pipe (3). The third branch pipe (3) has one end connected between the check valve (CV-6) and the fourth expansion valve (EV-4) and the other end connected to the second heating heat exchanger (HEX3b). It is connected between the second outdoor heat exchanger (HEX5b). The third branch pipe (3) is a check that allows only the fifth expansion valve (EV-5) and the refrigerant flow from the one end to the other end in order from the one end to the other end. And a valve (CV-7). And it is comprised so that a refrigerant | coolant can be flowed by bypassing a 2nd heating heat exchanger (HEX3b) and a non-return valve (CV-6).
[0065]
  The third circuit (10c) constituting the primary circuit (10) includes a third compressor (11c), a third four-way switching valve (12c), a third outdoor heat exchanger (HEX5c), and a sixth expansion. This is a closed circuit in which a valve (EV-6) and a third main heat exchanger (HEX2c) are sequentially connected by a main pipe (5c). The third circuit (10c) is configured to only supply hot or cold heat to the secondary circuit (20).
[0066]
      -Driving action-
  First, an operation operation during the cooling operation will be described.
[0067]
  During this operation, in the first circuit (10a), the first four-way switching valve (12a) is switched as shown by the solid line in FIG. 5, and the first expansion valve (EV-1) is adjusted to fully open, The second expansion valve (EV-2) and the third expansion valve (EV-3) are adjusted to a predetermined opening degree. In addition, when a high-pressure gas refrigerant is supplied to the first heating heat exchanger (HEX3a), the solenoid valve (SV) is opened.
[0068]
  In this state, the refrigerant circulates in the first circuit (10a) as indicated by solid arrows in FIG. That is, the high-pressure gas refrigerant discharged from the first compressor (11a) is divided and partly flows toward the first outdoor heat exchanger (HEX5a), and the rest is the first heating heat exchanger (HEX3a). It flows toward. The high-pressure gas refrigerant directed to the first outdoor heat exchanger (HEX5a) flows through the main pipe (5a), through the first four-way switching valve (12a) to the first outdoor heat exchanger (HEX5a), One outdoor heat exchanger (HEX5a) exchanges heat with the outside air to condense into a high-pressure liquid refrigerant. On the other hand, the high-pressure gas refrigerant directed to the first heating heat exchanger (HEX3a) flows to the first heating heat exchanger (HEX3a) through the first branch pipe (1), and the first heating heat exchanger (HEX3a). The heat exchange with the liquid refrigerant in the secondary circuit (20) is condensed and the liquid refrigerant in the secondary circuit (20) is evaporated. The refrigerant condensed in the first outdoor heat exchanger (HEX5a) into a high-pressure liquid refrigerant is diverted after passing through the first expansion valve (EV-1), and part of it is a cooling heat exchanger (HEX4). The rest flows through the main pipe (5a). The high-pressure liquid refrigerant going to the cooling heat exchanger (HEX4) flows through the second branch pipe (2) and is decompressed by the third expansion valve (EV-3) to become a low-pressure liquid refrigerant, and then the cooling heat exchanger (HEX4) evaporates by exchanging heat with the gas refrigerant in the secondary circuit (20) to condense the gas refrigerant in the secondary circuit (20). On the other hand, the high-pressure liquid refrigerant flowing through the main pipe (5a) merges with the high-pressure liquid refrigerant condensed in the first heating heat exchanger (HEX3a) and flows through the main pipe (5a), and the second expansion valve (EV- In 2), the pressure is reduced to become a low-pressure liquid refrigerant, and then the refrigerant is evaporated by exchanging heat with the refrigerant in the secondary circuit (20) in the first main heat exchanger (HEX2a). At that time, cold heat is generated in the first circuit (10a), and the cold heat is supplied to the refrigerant in the secondary circuit (20). The refrigerant in the first circuit (10a) evaporated in the first main heat exchanger (HEX2a) and the cooling heat exchanger (HEX4) is merged and then sucked into the first compressor (11a), and this circulation is repeated.
[0069]
  Further, when the high-pressure gas refrigerant is not supplied to the first heating heat exchanger (HEX3a), the solenoid valve (SV) is closed in the above state. In this state, the refrigerant does not flow to the first branch pipe (1), and the high-pressure gas refrigerant in the first circuit (10a) does not flow to the first heating heat exchanger (HEX3a).
[0070]
  In the second circuit (10b), the second four-way switching valve (12b) is switched as shown by the solid line in FIG. 5, and the fourth expansion valve (EV-4) is adjusted to a predetermined opening.
[0071]
  In this state, the refrigerant circulates in the second circuit (10b) as indicated by solid arrows in FIG. That is, the high-pressure gas refrigerant discharged from the second compressor (11b) flows to the second outdoor heat exchanger (HEX5b) through the second four-way switching valve (12b), and the second outdoor heat exchanger ( HEX5b) heat-condenses with the outside air and condenses to become a high-pressure liquid refrigerant. This high-pressure liquid refrigerant flows to the second heating heat exchanger (HEX3b) through the main pipe (5b), and exchanges heat with the liquid refrigerant in the secondary circuit (20) in the second heating heat exchanger (HEX3b). Then, the liquid refrigerant in the secondary circuit (20) is evaporated. The high-pressure liquid refrigerant flowing out of the heating heat exchanger flows through the main pipe (5b) and is depressurized by the fourth expansion valve (EV-4) to become a low-pressure liquid refrigerant, and then the second main heat exchanger ( HEX2b) evaporates by exchanging heat with the refrigerant in the secondary circuit (20). At that time, cold heat is generated in the second circuit (10b), and the cold heat is supplied to the refrigerant in the secondary circuit (20). The refrigerant in the second circuit (10b) evaporated by the second main heat exchanger (HEX2b) is then drawn into the second compressor (11b) and repeats this circulation.
[0072]
  In the third circuit (10c), the third four-way switching valve (12c) is switched as shown by the solid line in FIG. 5, and the sixth expansion valve (EV-6) is adjusted to a predetermined opening.
[0073]
  In this state, the refrigerant circulates in the second circuit (10b) as indicated by solid arrows in FIG. That is, the high-pressure gas refrigerant discharged from the third compressor (11c) flows to the third outdoor heat exchanger (HEX5c) through the third four-way switching valve (12c), and the third outdoor heat exchanger (HEX5c) HEX5c) exchanges heat with the outside air to condense into a high-pressure liquid refrigerant. This high-pressure liquid refrigerant flows through the main pipe (5c) and is reduced in pressure by the sixth expansion valve (EV-6) to become a low-pressure liquid refrigerant, and then in the third main heat exchanger (HEX2c) Evaporates by heat exchange with refrigerant (20). At that time, cold heat is generated in the third circuit (10c), and the cold heat is supplied to the refrigerant in the secondary circuit (20). The refrigerant of the third circuit (10c) evaporated by the third main heat exchanger (HEX2c) is then sucked into the third compressor (11c) and repeats this circulation.
[0074]
  And the primary side circuit (10) which consists of said 1st-3rd circuit (10a-10c) supplies the high voltage | pressure liquid refrigerant of a 2nd circuit (10b) to a 2nd heating heat exchanger (HEX3b). In an operation state where a sufficiently high pressure can be generated, the solenoid valve (SV) of the first circuit (10a) is closed, and the refrigerant of the first circuit (10a) is not supplied to the first heating heat exchanger (HEX3a). That is, in this operating state, the refrigerant in the secondary circuit (20) is circulated using the high pressure generated only by the second heating heat exchanger (HEX3b). On the other hand, in the operation state in which sufficient high pressure cannot be generated in the second heating heat exchanger (HEX3b), the refrigerant in the secondary side circuit (20) cannot be reliably circulated. In this case, the primary side circuit (10) opens the solenoid valve (SV) of the first circuit (10a) to the first heating heat exchanger (HEX3a) and the high pressure of the first circuit (10a). Supply gas refrigerant. Thereby, even in the above-described operation state, a high pressure is generated in the first heating heat exchanger (HEX3a), and the refrigerant in the secondary side circuit (20) can be circulated using the high pressure.
[0075]
  In the secondary circuit (20), a high pressure is generated in the carrier circuit (30) by evaporation of the refrigerant in the secondary circuit (20) in the first and second heating heat exchangers (HEX3a, HEX3b). The low pressure is generated by the condensation of the refrigerant in the secondary circuit (20) in the cooling heat exchanger (HEX4). Then, the high pressure of the first and second heating heat exchangers (HEX3a, HEX3b) and the low pressure of the cooling heat exchanger (HEX4) are supplied to the first and second main tanks (T1, T2). The secondary side circuit (20) operates in the same manner as described above to push out and collect the liquid refrigerant in each main tank (T1, T2). On the other hand, in the main circuit (21), the refrigerant circulates and cools the room in substantially the same manner as in the cooling operation of the first embodiment. That is, the refrigerant evaporated in the indoor heat exchanger (HEX1) flows in a divided manner to the first to third main heat exchangers (HEX2a to HEX2c) and flows to the first to third main heat exchangers (HEX2a to HEX2c). Only the point of condensation by exchanging heat with the refrigerant of the third circuit (10a to 10c) is different from the operation in the first embodiment.
[0076]
  Next, the operation operation at the time of heating operation will be described.
[0077]
  During this operation, in the first circuit (10a), the first four-way switching valve (12a) is switched as shown by the broken line in FIG. 5, and the second expansion valve (EV-2) is adjusted to full open, The first expansion valve (EV-1) and the third expansion valve (EV-3) are adjusted to a predetermined opening, and the electromagnetic valve (SV) is opened.
[0078]
  In this state, the refrigerant circulates in the first circuit (10a) as indicated by solid arrows in FIG. That is, the high-pressure gas refrigerant discharged from the first compressor (11a) is divided and partly flows toward the first main heat exchanger (HEX2a), and the rest is the first heating heat exchanger (HEX3a). It flows toward. The high-pressure gas refrigerant going to the first main heat exchanger (HEX2a) flows to the first main heat exchanger (HEX2a) through the first four-way switching valve (12a), and the first main heat exchanger (HEX2a) Thus, heat exchange with the refrigerant in the secondary circuit (20) condenses and becomes a high-pressure liquid refrigerant. At that time, warm heat is generated in the first circuit (10a), and the warm heat is supplied to the refrigerant in the secondary circuit (20). On the other hand, the high-pressure gas refrigerant directed to the first heating heat exchanger (HEX3a) flows to the first heating heat exchanger (HEX3a) through the first branch pipe (1), and the first heating heat exchanger (HEX3a). The heat exchange with the liquid refrigerant in the secondary circuit (20) is condensed and the liquid refrigerant in the secondary circuit (20) is evaporated. The refrigerant that has condensed in the first main heat exchanger (HEX2a) and the first heating heat exchanger (HEX3a) to become a high-pressure liquid refrigerant once merged and flows again through the second branch pipe (2). After being divided, a part flows toward the first outdoor heat exchanger (HEX5a), and the rest flows toward the cooling heat exchanger (HEX4). The high-pressure liquid refrigerant going to the first outdoor heat exchanger (HEX5a) is reduced in pressure by the first expansion valve (EV-1) to become a low-pressure liquid refrigerant, and then passes through the main pipe (5a) to the first outdoor heat. It flows to the exchanger (HEX5a) and evaporates by exchanging heat with the outside air in the first outdoor heat exchanger (HEX5a). On the other hand, the high-pressure liquid refrigerant going to the cooling heat exchanger (HEX4) flows through the second branch pipe (2) and is reduced in pressure by the third expansion valve (EV-3) to become low-pressure liquid refrigerant. The exchanger (HEX4) exchanges heat with the gas refrigerant in the secondary circuit (20) and evaporates to condense the gas refrigerant in the secondary circuit (20). The refrigerant in the first circuit (10a) evaporated in the first outdoor heat exchanger (HEX5a) and the cooling heat exchanger (HEX4) joins and then is sucked into the first compressor (11a) and repeats this circulation.
[0079]
  In the second circuit (10b), the second four-way switching valve (12b) is switched as indicated by a broken line in FIG. 5, the fourth expansion valve (EV-4) is adjusted to full open, and the fifth expansion valve ( EV-5) is adjusted to the predetermined opening.
[0080]
  In this state, the refrigerant circulates in the second circuit (10b) as indicated by solid arrows in FIG. That is, the high-pressure gas refrigerant discharged from the second compressor (11b) flows to the second main heat exchanger (HEX2b) through the second four-way switching valve (12b), and the second main heat exchanger ( HEX2b) exchanges heat with the refrigerant in the secondary circuit (20) to condense into a high-pressure liquid refrigerant. At that time, warm heat is generated in the second circuit (10b), and the warm heat is supplied to the refrigerant in the secondary circuit (20). The high-pressure liquid refrigerant condensed in the second main heat exchanger (HEX2b) flows from the main pipe 2 into the third branch pipe (3) and is decompressed by the fifth expansion valve (EV-5) to be low-pressure liquid refrigerant. It becomes. The low-pressure liquid refrigerant flows to the second outdoor heat exchanger (HEX5b) through the main pipe (5b), and evaporates by exchanging heat with the outside air in the second outdoor heat exchanger (HEX5b). The gas refrigerant in the second circuit (10b) evaporated in the second outdoor heat exchanger (HEX5b) is sucked into the second compressor (11b) through the second four-way switching valve (12b), and this circulation is performed. repeat. In this operation state, the refrigerant of the second circuit (10b) is not supplied to the second heating heat exchanger (HEX3b).
[0081]
  In the third circuit (10c), the third four-way switching valve (12c) is switched as indicated by a broken line in FIG. 5, and the sixth expansion valve (EV-6) is adjusted to a predetermined opening.
[0082]
  In this state, the refrigerant circulates in the third circuit (10c) as indicated by solid arrows in FIG. That is, the high-pressure gas refrigerant discharged from the third compressor (11c) flows to the third main heat exchanger (HEX2c) through the third four-way switching valve (12c), and the third main heat exchanger ( HEX2c) exchanges heat with the refrigerant in the secondary circuit (20) to condense into a high-pressure liquid refrigerant. At that time, warm heat is generated in the third circuit (10c), and the warm heat is supplied to the refrigerant in the secondary circuit (20). The refrigerant that has condensed in the third main heat exchanger (HEX2c) to become a high-pressure liquid refrigerant is decompressed by the sixth expansion valve (EV-6) to become a low-pressure liquid refrigerant. The low-pressure liquid refrigerant flows to the third outdoor heat exchanger (HEX5c) through the main pipe (5c), and evaporates by exchanging heat with the outside air in the third outdoor heat exchanger (HEX5c). The gas refrigerant in the third circuit (10c) evaporated in the third outdoor heat exchanger (HEX5c) is sucked into the third compressor (11c) through the third four-way switching valve (12c), and this circulation is performed. repeat.
[0083]
  Further, in the secondary circuit (20), in the transport circuit (30), a high pressure is generated by evaporation of the refrigerant in the secondary circuit (20) in the first heating heat exchanger (HEX3a), and the cooling heat exchanger A low pressure is generated by the condensation of the refrigerant in the secondary circuit (20) in (HEX4). Then, the high pressure of the first and second heating heat exchangers (HEX3a, HEX3b) and the low pressure of the cooling heat exchanger (HEX4) are supplied to the first and second main tanks (T1, T2). The secondary side circuit (20) operates in the same manner as described above to push out and collect the liquid refrigerant in each main tank (T1, T2). On the other hand, in the main circuit (21), the refrigerant circulates and heats the room in substantially the same manner as in the heating operation of the first embodiment. That is, the liquid refrigerant pushed out from each main tank (T1, T2) flows in a divided manner to the first to third main heat exchangers (HEX2a to HEX2c), and in each main heat exchanger (HEX2a to HEX2c) Only the point of evaporating by exchanging heat with the refrigerant of the first to third circuits (10a to 10c) is different from the operation in the first embodiment.
[0084]
      -Effect of Embodiment 2-
  According to the second embodiment, the same effect as that obtained in the first embodiment can be obtained. That is, the refrigerant in the secondary side circuit (20) cannot be reliably circulated in an operation state in which a sufficiently high pressure cannot be generated in the second heating heat exchanger (HEX3b). On the other hand, the primary side circuit (10) of the present embodiment opens the solenoid valve (SV) of the first circuit (10a) and supplies the first circuit (10a) to the first heating heat exchanger (HEX3a). ) High-pressure gas refrigerant. Thereby, even in the above-described operation state, a high pressure can be generated by the first heating heat exchanger (HEX3a), and the refrigerant in the secondary circuit (20) can be circulated using the high pressure. As a result, the refrigerant circulation in the secondary circuit (20) can be sufficiently ensured regardless of the operating state, and the heat or cold of the primary circuit (10) is transferred to the indoor heat exchanger (HEX1). By doing so, it is possible to always ensure the air conditioning capability.
[Brief description of the drawings]
FIG. 1 is a refrigerant piping system diagram of an air-conditioning apparatus according to Embodiment 1. FIG.
FIG. 2 is a diagram illustrating a refrigerant circulation operation during an operation in which high-pressure liquid refrigerant in a primary circuit is supplied to a heating heat exchanger during cooling operation of the air-conditioning apparatus according to Embodiment 1.
FIG. 3 is a diagram illustrating a refrigerant circulation operation during an operation in which a high-pressure gas refrigerant in a primary circuit is supplied to a heating heat exchanger during a cooling operation of the air-conditioning apparatus according to Embodiment 1.
4 is a diagram illustrating a refrigerant circulation operation during heating operation of the air-conditioning apparatus according to Embodiment 1. FIG.
FIG. 5 is a refrigerant piping system diagram of the air-conditioning apparatus according to Embodiment 2.
6 is a diagram illustrating a refrigerant circulation operation during a cooling operation of the air-conditioning apparatus according to Embodiment 2. FIG.
FIG. 7 is a diagram illustrating a refrigerant circulation operation during heating operation of the air-conditioning apparatus according to Embodiment 2.
[Explanation of symbols]
  (10) Primary side circuit (heat source side refrigerant circuit)
  (11) Compressor
  (11a-11c) 1st-3rd compressor
  (20) Secondary circuit (use-side refrigerant circuit)
  (30) Transport circuit (Transport means)
  (HEX1) Indoor heat exchanger (use side heat exchanger)
  (HEX2) Main heat exchanger
  (HEX3) Heating heat exchanger (pressurizing means)
  (HEX3a, HEX3b) 1st and 2nd heating heat exchanger (pressurizing means)
  (HEX4) Cooling heat exchanger (pressure reduction means)
  (HEX5) Outdoor heat exchanger
  (T1) 1st main tank
  (T2) Second main tank

Claims

A heat source side refrigerant circuit which generates a heat or cold (10), to circulate the refrigerant by the conveying means (30), conveying the heat or cold of the heat source side refrigerant circuit (10) utilization side heat exchanger (HEX 1) A refrigeration apparatus comprising a utilization side refrigerant circuit ( 20 ) for causing the utilization side heat exchanger ( HEX1 ) to perform an endothermic operation or a heat radiation operation ,
It said conveying means (30) is provided with a pressure reducing means for generating a low pressure and pressurizing means (HEX3) for generating a high voltage (HEX4), at high pressure and reduced pressure means generated by pressurizing means (HEX3) (HEX4) It is configured to give a circulation driving force to the refrigerant in the use side refrigerant circuit ( 20 ) by the difference from the generated low pressure ,
The pressurizing means ( HEX3 ) receives supply of refrigerant from the heat source side refrigerant circuit ( 10 ), heats and evaporates the liquid refrigerant in the use side refrigerant circuit ( 20 ) by heat exchange with the refrigerant, and generates high pressure Configured as
The heat source side refrigerant circuit ( 10 ) includes a closed circuit that includes a compressor ( 11 ) and constitutes a vapor compression refrigeration cycle, and the heat source side refrigerant circuit ( 10 ) is at the time of heat absorption operation of the use side heat exchanger ( HEX1 ). The high-pressure liquid refrigerant flowing out of the condenser of ( 10 ) and the high-pressure gas refrigerant discharged from the compressor ( 11 ) can be supplied to the pressurizing means ( HEX3 ),
Further, the heat source side refrigerant circuit (10) comprises one closed circuit including a compressor (11), and the refrigerant supplied to the pressurizing means (HEX3) can be switched between the high pressure liquid refrigerant and the high pressure gas refrigerant. A refrigeration apparatus comprising:

A heat source side refrigerant circuit which generates a heat or cold (10), to circulate the refrigerant by the conveying means (30), conveying the heat or cold of the heat source side refrigerant circuit (10) utilization side heat exchanger (HEX 1) A refrigeration apparatus comprising a utilization side refrigerant circuit ( 20 ) for causing the utilization side heat exchanger ( HEX1 ) to perform an endothermic operation or a heat radiation operation ,
It said conveying means (30) is provided with a pressure reducing means for generating a low pressure and pressurizing means (HEX3) for generating a high voltage (HEX4), at high pressure and reduced pressure means generated by pressurizing means (HEX3) (HEX4) It is configured to give a circulation driving force to the refrigerant in the use side refrigerant circuit ( 20 ) by the difference from the generated low pressure ,
The pressurizing means ( HEX3 ) receives supply of refrigerant from the heat source side refrigerant circuit ( 10 ), heats and evaporates the liquid refrigerant in the use side refrigerant circuit ( 20 ) by heat exchange with the refrigerant, and generates high pressure Configured as
The heat source side refrigerant circuit ( 10 ) includes a closed circuit that includes a compressor ( 11 ) and constitutes a vapor compression refrigeration cycle, and the heat source side refrigerant circuit ( 10 ) is at the time of heat absorption operation of the use side heat exchanger ( HEX1 ). The high-pressure liquid refrigerant flowing out of the condenser of ( 10 ) and the high-pressure gas refrigerant discharged from the compressor ( 11 ) can be supplied to the pressurizing means ( HEX3 ),
Furthermore, the heat source side refrigerant circuit (10) is composed of a plurality of closed circuits each having a compressor (11a to 11c),
A plurality of closed circuit constituting the heat source side refrigerant circuit (10) (10a, 10b, 10c) , a part of the closed circuit of which (10b) is fed only the high-pressure liquid refrigerant to the pressurizing means (HEX3b) is configured to, remaining at least one closed circuit (10a) has only a state for supplying the high-pressure gas refrigerant to the pressurizing means (HEX3a), the high-pressure liquid refrigerant and the above pressurizing means (HEX3a) A refrigeration apparatus configured to be switchable to a state where none of the high-pressure gas refrigerant is supplied .