JP2006125793A

JP2006125793A - Air conditioner

Info

Publication number: JP2006125793A
Application number: JP2004317458A
Authority: JP
Inventors: Masayuki Nonaka; 正之野中; Hiroo Nakamura; 啓夫中村; Kazutoshi Ota; 和利太田; Tatsuya Hizume; 達也樋爪
Original assignee: Hitachi Home and Life Solutions Inc
Current assignee: Hitachi Appliances Inc
Priority date: 2004-11-01
Filing date: 2004-11-01
Publication date: 2006-05-18
Also published as: CN1769813A; CN100498122C

Abstract

<P>PROBLEM TO BE SOLVED: To implement optimal injection even when a resisting value of a pressure reducer is changed by individual difference of a pressure reduction adjusting means and accumulation of dusts, in an air conditioner wherein a refrigerant is injected from a gas-liquid separator 4 to a refrigerant outlet portion of a lower stage-side compressing portion 1b of a compressor 1, and controlling the injection by a pressure reducing means on a downstream side of the gas-liquid separator 4. <P>SOLUTION: The pressure reduction by the pressure reducing means 3, 5 on the downstream side of the gas-liquid separator 4 are determined on the basis of the difference between a lower stage-side compressing portion discharge temperature 8 and a higher stage-side compressing portion suction temperature 7 of a two-stage compressor 1 having the lower stage-side compressing portion 1b and the higher stage-side compressing portion 1a. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

本発明は空気調和装置に係り、ガスインジェクションに関する。 The present invention relates to an air conditioner and relates to gas injection.

空気調和装置の省電力化に関する技術として、蒸発能力に寄与しないガス冷媒を圧縮過程の途中にインジェクションさせて、圧縮動力を低減するガスインジェクションシステムが知られている。すなわち、圧縮機と、この圧縮機に接続され、冷房運転と暖房運転における冷媒流れ方向を切換える冷媒流れ方向切換え手段と、この冷媒流れ方向切換え手段に接続された第１の熱交換器と、この第１の熱交換器に接続された第一減圧手段と、この第一減圧手段に接続された気液分離器と、この気液分離器に接続された第二減圧手段と、一方がこの第一減圧手段に接続され、他方が前記冷媒流れ方向切換え手段に接続された第２の熱交換器と、前記気液分離器と前記圧縮機の中間圧部分とを接続するインジェクション配管と、このインジェクション配管に設けられた二方弁とを備え、第一減圧手段及び第二減圧手段の減圧量を調整することで、気液分離器内を圧縮機吸込み圧力と吐出圧力の中間圧とし、蒸発能力に寄与しないガス冷媒を圧縮機の中間圧力部分にインジェクションする。 A gas injection system that reduces compression power by injecting a gas refrigerant that does not contribute to the evaporation capability in the middle of a compression process is known as a technique related to power saving of an air conditioner. That is, a compressor, a refrigerant flow direction switching unit that is connected to the compressor and switches a refrigerant flow direction in cooling operation and heating operation, a first heat exchanger connected to the refrigerant flow direction switching unit, A first pressure reducing means connected to the first heat exchanger, a gas-liquid separator connected to the first pressure reducing means, and a second pressure reducing means connected to the gas-liquid separator, one of which is this first A second heat exchanger connected to one decompression means and the other connected to the refrigerant flow direction switching means; an injection pipe connecting the gas-liquid separator and the intermediate pressure portion of the compressor; and the injection Equipped with a two-way valve provided in the piping, and by adjusting the pressure reduction amount of the first pressure reducing means and the second pressure reducing means, the gas-liquid separator is set to an intermediate pressure between the compressor suction pressure and the discharge pressure, and the evaporation capacity Compress gas refrigerant that does not contribute to It is injected to the intermediate pressure part of.

ガスインジェクションは、減圧手段による一回目と二回目の減圧量によって気液分離器内の圧力が定まり、この圧力によりインジェクション量や気液分離性能が変化し、これらに伴い空気調和装置の効率が変化する。すなわち、気液分離器の圧力には適正値があり、この適正化の方法として特許文献１には、圧縮機回転数と外気温度に応じて下流側の減圧手段の絞り量を制御することが記載されている。 In gas injection, the pressure in the gas-liquid separator is determined by the first and second decompression amounts by the decompression means, and this pressure changes the injection amount and gas-liquid separation performance, which in turn changes the efficiency of the air conditioner. To do. That is, there is an appropriate value for the pressure of the gas-liquid separator, and as a method for this optimization, Patent Document 1 discloses that the throttle amount of the pressure reducing means on the downstream side is controlled according to the compressor rotational speed and the outside air temperature. Are listed.

特開２００２−８１７６９号公報JP 2002-81769 A

気液分離器の圧力を適正化するために、特許文献１に示された空気調和機は、圧縮機回転数と外気温度に応じて下流側の減圧手段の減圧量を制御している。しかし、実際の冷凍サイクルの状態に基づいて制御していないため、減圧手段の調整減圧量の個体差や、ゴミなどの堆積による流路抵抗値の変化には対応できないので、必ずしも減圧手段における減圧量が最適なガスインジェクション状態にならない場合があった。 In order to optimize the pressure of the gas-liquid separator, the air conditioner disclosed in Patent Document 1 controls the pressure reduction amount of the downstream pressure reducing means according to the compressor rotation speed and the outside air temperature. However, since it is not controlled based on the actual refrigeration cycle state, it cannot cope with individual differences in the adjusted decompression amount of the decompression means or changes in the channel resistance value due to accumulation of dust, etc. In some cases, the amount was not optimal for gas injection.

本発明の目的は、ガスインジェクションを行う空気調和装置において、最適なガスインジェクションに近づけた空気調和装置を提供することにある。 An object of the present invention is to provide an air conditioner that is close to an optimum gas injection in an air conditioner that performs gas injection.

上記目的は、低圧側圧縮部と高圧側圧縮部を有する二段圧縮機と、この二段圧縮機に接続された第二熱交換器と、この第二熱交換器に接続され開度の調節が可能な第二減圧手段と、この第二減圧手段に接続された気液分離器と、この気液分離器に接続され開度の調節が可能な第一減圧手段と、一方がこの第一減圧手段に接続され、他方が前記二段圧縮機に接続された第一熱交換器とを有する冷凍サイクルと、前記気液分離器と前記圧縮機の低圧側圧縮部の冷媒吐出部と高圧側圧縮機部の冷媒吸込部との間の中間冷媒流路とを接続するインジェクション配管とを備えた空気調和装置において、前記中間冷媒流路と前記インジェクション配管との接続部よりも高段側圧縮部よりの吸込部分に高段側吸込温度検出手段を設けることにより達成される。 The purpose is to adjust the opening degree of a two-stage compressor having a low-pressure side compressor and a high-pressure side compressor, a second heat exchanger connected to the two-stage compressor, and the second heat exchanger. A second pressure reducing means capable of operating, a gas-liquid separator connected to the second pressure reducing means, a first pressure reducing means connected to the gas-liquid separator and capable of adjusting the opening degree, one of which is the first pressure reducing means. A refrigeration cycle having a first heat exchanger connected to the decompression means and the other connected to the two-stage compressor, a refrigerant discharge section and a high pressure side of the gas-liquid separator and the low pressure side compression section of the compressor In an air conditioner including an injection pipe that connects an intermediate refrigerant flow path between the refrigerant suction section of the compressor section and a connection section between the intermediate refrigerant flow path and the injection pipe, a higher-stage compression section This is achieved by providing a higher stage suction temperature detection means at the suction part

上記目的は、低圧側圧縮部と高圧側圧縮部を有し、この低圧側圧縮部の冷媒吐出部とこの高圧側圧縮部の冷媒吸込部との間に中間冷媒流路とを有する二段圧縮機と、この二段圧縮機に接続された第二熱交換器と、この第二熱交換器に接続され開度の調節が可能な第二減圧手段と、この第二減圧手段に接続された気液分離器と、この気液分離器に接続され開度の調節が可能な第一減圧手段と、一方がこの第一減圧手段に接続され、他方が前記二段圧縮機に接続された第一熱交換器とを有する冷凍サイクルと、前記気液分離器と前記中間冷媒流路とを接続するインジェクション配管とを備えた空気調和装置において、前記中間冷媒流路は前記二段圧縮機の密閉容器外に露出した冷媒配管を有し、前記インジェクション配管と前記中間冷媒流路の密閉容器外に露出した冷媒配管との接続部よりも冷媒流れ方向下流の前記密閉容器外に露出した冷媒配管に高段側吸込温度検出手段を設けることにより達成される。 The above-described object is a two-stage compression having a low pressure side compression section and a high pressure side compression section, and having an intermediate refrigerant flow path between the refrigerant discharge section of the low pressure side compression section and the refrigerant suction section of the high pressure side compression section. A second heat exchanger connected to the two-stage compressor, a second pressure reducing means connected to the second heat exchanger and capable of adjusting an opening degree, and connected to the second pressure reducing means A gas-liquid separator, a first pressure-reducing means connected to the gas-liquid separator and capable of adjusting an opening, one connected to the first pressure-reducing means, and the other connected to the two-stage compressor. An air conditioner comprising: a refrigeration cycle having a single heat exchanger; and an injection pipe connecting the gas-liquid separator and the intermediate refrigerant flow path, wherein the intermediate refrigerant flow path is hermetically sealed with the two-stage compressor A refrigerant pipe exposed to the outside of the container, wherein the injection pipe and the intermediate refrigerant flow path are It is achieved by providing a high-stage suction temperature detecting means to the refrigerant pipe exposed outside the closed container of the refrigerant flow direction downstream from the connecting portion between the refrigerant pipe exposed to the outside of the container.

上記目的は、低圧側圧縮部と高圧側圧縮部を有する二段圧縮機と、この二段圧縮機に接続された冷媒流れ方向切換え手段と、この冷媒流れ方向切換え手段に接続された室内熱交換器と、この室内熱交換器に接続され開度の調節が可能な第二減圧手段と、この第二減圧手段に接続された気液分離器と、この気液分離器に接続され開度の調節が可能な第一減圧手段と、一方がこの第一減圧手段に接続され、他方が前記冷媒流れ方向切換え手段に接続された室外熱交換器とを有する冷凍サイクルと、前記気液分離器と前記圧縮機の低圧側圧縮部の冷媒吐出部と高圧側圧縮機部の冷媒吸込部との間の中間冷媒流路とを接続するインジェクション配管とを備えた空気調和装置において、前記中間冷媒流路と前記インジェクション配管との接続部よりも高段側圧縮部よりの吸込部分に高段側吸込温度検出手段を設けることにより達成される。 The object is to provide a two-stage compressor having a low-pressure compressor and a high-pressure compressor, refrigerant flow direction switching means connected to the two-stage compressor, and indoor heat exchange connected to the refrigerant flow direction switching means. , A second decompression unit connected to the indoor heat exchanger and capable of adjusting the opening degree, a gas-liquid separator connected to the second decompression unit, and an opening degree connected to the gas-liquid separator. A refrigeration cycle having an adjustable first pressure reducing means, an outdoor heat exchanger connected to the refrigerant flow direction switching means, one connected to the first pressure reducing means, and the gas-liquid separator; In the air conditioner comprising an injection pipe connecting an intermediate refrigerant flow path between a refrigerant discharge part of a low pressure side compression part of the compressor and a refrigerant suction part of a high pressure side compressor part, the intermediate refrigerant flow path Higher than the connection between the pipe and the injection pipe Is achieved by providing a high-stage suction temperature detecting means to the suction portion of the from the side compression unit.

上記目的は、低圧側圧縮部と高圧側圧縮部を有し、この低圧側圧縮部の冷媒吐出部とこの高圧側圧縮部の冷媒吸込部との間に中間冷媒流路とを有する二段圧縮機と、この二段圧縮機に接続された冷媒流れ方向切換え手段と、この冷媒流れ方向切換え手段に接続された室内熱交換器と、この室内熱交換器に接続され開度の調節が可能な第二減圧手段と、この第二減圧手段に接続された気液分離器と、この気液分離器に接続され開度の調節が可能な第一減圧手段と、一方がこの第一減圧手段に接続され、他方が前記冷媒流れ方向切換え手段に接続された室外熱交換器とを有する冷凍サイクルと、前記気液分離器と前記中間冷媒流路とを接続するインジェクション配管とを備えた空気調和装置において、前記インジェクション配管と前記中間冷媒流路の密閉容器外に露出した冷媒配管との接続部よりも冷媒流れ方向下流の前記密閉容器外に露出した冷媒配管に高段側吸込温度検出手段を設けることにより達成される。 The above-described object is a two-stage compression having a low pressure side compression section and a high pressure side compression section, and having an intermediate refrigerant flow path between the refrigerant discharge section of the low pressure side compression section and the refrigerant suction section of the high pressure side compression section. , A refrigerant flow direction switching means connected to the two-stage compressor, an indoor heat exchanger connected to the refrigerant flow direction switching means, and an opening degree of which can be adjusted by being connected to the indoor heat exchanger A second pressure reducing means; a gas-liquid separator connected to the second pressure reducing means; a first pressure reducing means connected to the gas-liquid separator and capable of adjusting an opening; one of the first pressure reducing means An air conditioner comprising: a refrigeration cycle having an outdoor heat exchanger connected to the refrigerant flow direction switching means, and an injection pipe connecting the gas-liquid separator and the intermediate refrigerant flow path In the injection pipe and the intermediate refrigerant flow Than the connection portion with the refrigerant pipe which is exposed to the outside of the sealed container of it is accomplished by providing a high-stage suction temperature detecting means to the refrigerant pipe exposed outside the closed container of the refrigerant flow direction downstream.

以上本発明によれば、ガスインジェクションを行う空気調和装置において、最適なガスインジェクションに近づけた空気調和装置を提供することができる。 As mentioned above, according to this invention, in the air conditioning apparatus which performs gas injection, the air conditioning apparatus close | similar to the optimal gas injection can be provided.

以下、本発明の一実施例を図面に基づいて詳細に説明する。図１は、ガスインジェクションを有する空気調和装置における冷凍サイクルであり、暖房運転時の冷媒流れ方向を示している。二段圧縮機１は高段側（高圧側圧縮機部）１ａと低段側（低圧側圧縮機部）１ｂの２つの圧縮部を有する圧縮機であり、詳細は後述する。第一熱交換器としての室外熱交換器２は、暖房運転時は蒸発器（冷房運転時は凝縮器）として作用する。第二電動膨張弁５は冷媒流れ方向上流側に設けられた（冷房運転時は下流側となる）減圧量可変の減圧手段である。第一電動膨張弁３は冷媒流れ方向下流側に位置する（冷房運転時は上流側となる）減圧量可変の減圧手段である。気液分離器４は、第一電動膨張弁３と第二電動膨張弁５との間に設けられ、気体冷媒と液冷媒とを分離する機能を有している。第二熱交換器としての室内熱交換器６は暖房運転時に凝縮器として作用する（冷房運転時は蒸発器として作用する）。 Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a refrigeration cycle in an air conditioner having gas injection, and shows the direction of refrigerant flow during heating operation. The two-stage compressor 1 is a compressor having two compression sections, a high-stage side (high-pressure side compressor section) 1a and a low-stage side (low-pressure side compressor section) 1b, which will be described in detail later. The outdoor heat exchanger 2 as the first heat exchanger acts as an evaporator during heating operation (condenser during cooling operation). The second electric expansion valve 5 is a pressure reducing means having a variable pressure reducing amount provided on the upstream side in the refrigerant flow direction (on the downstream side during the cooling operation). The first electric expansion valve 3 is a pressure reducing means with a variable pressure reducing amount located downstream in the refrigerant flow direction (upstream during cooling operation). The gas-liquid separator 4 is provided between the first electric expansion valve 3 and the second electric expansion valve 5 and has a function of separating the gas refrigerant and the liquid refrigerant. The indoor heat exchanger 6 as the second heat exchanger acts as a condenser during heating operation (acts as an evaporator during cooling operation).

気液分離器４で分離された液あるいは低乾き度の冷媒は第一電動膨張弁３へ流れるように構成されている。また気液分離器４で分離されたガスあるいは高乾き度の冷媒は二段圧縮機1の低段側圧縮部１ｂの吐出部に流れるように構成されている。高段側吸込温度センサ７は二段圧縮機１の高段側１ａの吸込温度検出手段であり、低段側吐出温度センサ８は二段圧縮機１の低段側１ｂの吐出温度検出手段である。また、高段側吐出温度センサ９は二段圧縮機１の高段側１ａの吐出温度検出手段である。演算装置１０は、図２に示す制御プログラムを備えている。二方弁１２は、インジェクション配管１１に設けられた「開」あるいは「閉」を設定できる。なお、１３は室外送風ファン、１４は室内送風ファンである。 The liquid separated by the gas-liquid separator 4 or the low dryness refrigerant is configured to flow to the first electric expansion valve 3. The gas separated by the gas-liquid separator 4 or the high dryness refrigerant is configured to flow to the discharge section of the low-stage compression section 1b of the two-stage compressor 1. The high stage side suction temperature sensor 7 is a suction temperature detection means on the high stage side 1 a of the two-stage compressor 1, and the low stage side discharge temperature sensor 8 is a discharge temperature detection means on the low stage side 1 b of the two-stage compressor 1. is there. The high stage discharge temperature sensor 9 is a discharge temperature detecting means for the high stage 1 a of the two-stage compressor 1. The arithmetic device 10 includes a control program shown in FIG. The two-way valve 12 can be set to “open” or “closed” provided in the injection pipe 11. In addition, 13 is an outdoor ventilation fan, 14 is an indoor ventilation fan.

以上のように構成された空気調和装置の動作を図１及び図２に基いて説明する。ステップ１０１にて運転がスタート（図示は暖房運転）されると、二方弁１２が開いていたら閉じ、第一電動膨張弁３と第二電動膨張弁５の開度を初期設定値とする（ステップ１０２）。この状態で二段圧縮機１が起動すると、二段圧縮機１で圧縮された高温高圧の冷媒ガスは、冷媒流れ方向切換え手段である四方弁１５を介して室内熱交換器６に至り、室内送風ファン１４により送風される空気に放熱して凝縮する。第二電動膨張弁５で吐出圧力と吸込圧力に対して中間となる圧力まで減圧され、気液分離器４に至る。このとき二方弁１２は閉じているので全ての冷媒は第一電動膨張弁３でさらに減圧されて低温低圧の冷媒となる。低温低圧の気液二相状態の冷媒は、室外熱交換器２で室外送風ファン１３により送風される空気から吸熱して蒸発し、再び二段圧縮機１に戻る。 The operation of the air conditioner configured as described above will be described with reference to FIGS. When the operation is started at step 101 (heating operation in the drawing), the two-way valve 12 is closed if it is open, and the opening degrees of the first electric expansion valve 3 and the second electric expansion valve 5 are set as initial setting values ( Step 102). When the two-stage compressor 1 is started in this state, the high-temperature and high-pressure refrigerant gas compressed by the two-stage compressor 1 reaches the indoor heat exchanger 6 via the four-way valve 15 which is a refrigerant flow direction switching means, The air blown by the blower fan 14 dissipates heat and condenses. The pressure is reduced to a pressure intermediate between the discharge pressure and the suction pressure by the second electric expansion valve 5, and the gas-liquid separator 4 is reached. At this time, since the two-way valve 12 is closed, all the refrigerant is further depressurized by the first electric expansion valve 3 to become a low-temperature and low-pressure refrigerant. The low-temperature and low-pressure gas-liquid two-phase refrigerant absorbs heat from the air blown by the outdoor fan 13 in the outdoor heat exchanger 2 and evaporates, and returns to the two-stage compressor 1 again.

次に二方弁１２を開くと（ステップ１０３）、気液分離器４で分離されたガス冷媒は二方弁１２を介して二段圧縮機１の低段側圧縮部１ｂの吐出部にバイパスされる。その後、演算制御器１０は、低段側吐出温度センサ８及び後段側吸込温度センサ７の出力を読み込み（ステップ１０４）、低段側吐出温度と高段側吸込温度の差を演算する。そして（低段側吐出温度）−（高段側吸込温度）＞１度で無い場合、すなわち低段側吐出温度と後段側吐出温度の差が一度以下の場合、まだ液混合ガスインジェクションではないと判定（ステップ１０５）する。 Next, when the two-way valve 12 is opened (step 103), the gas refrigerant separated by the gas-liquid separator 4 is bypassed to the discharge part of the low-stage side compression part 1b of the two-stage compressor 1 via the two-way valve 12. Is done. Thereafter, the arithmetic controller 10 reads the outputs of the low-stage discharge temperature sensor 8 and the rear-stage suction temperature sensor 7 (step 104), and calculates the difference between the low-stage discharge temperature and the high-stage suction temperature. And if (low stage side discharge temperature)-(high stage side suction temperature)> 1 degree, that is, if the difference between the low stage side discharge temperature and the rear stage side discharge temperature is once or less, it is still not a liquid mixed gas injection Determination is made (step 105).

ここで二段圧縮機１について図８を用いて詳細を説明する。二段圧縮機１は、底部２１と蓋部４０と胴部２２からなる密閉容器４１を備える。密閉容器４１内部の上方には、ステータ４２とロータ４３を有する電動機４４が設けられている。電動機４４に連結された回転軸４５は、２つの偏心部４６（４６ａ、４６ｂ）を備えて、主軸受４７と副軸受１９に軸支されている。その回転軸４５に対して電動機４４側から順に、端板部４８ａを備えた主軸受４７、高圧用（後段側）圧縮要素１ａ、中間仕切板４９、低圧用（低段側）圧縮要素１ｂ及び端板部１９ａを備えた副軸受１９が積層され、ボルト等の締結要素(図示せず)で一体化されている。 Here, the details of the two-stage compressor 1 will be described with reference to FIG. The two-stage compressor 1 includes a sealed container 41 including a bottom portion 21, a lid portion 40, and a body portion 22. An electric motor 44 having a stator 42 and a rotor 43 is provided above the inside of the sealed container 41. The rotating shaft 45 connected to the electric motor 44 includes two eccentric portions 46 (46 a and 46 b) and is supported by the main bearing 47 and the sub bearing 19. A main bearing 47 having an end plate portion 48a, a high-pressure (rear-stage) compression element 1a, an intermediate partition plate 49, a low-pressure (low-stage) compression element 1b, The auxiliary bearing 19 provided with the end plate portion 19a is laminated and integrated with a fastening element (not shown) such as a bolt.

端板部４８ａは、胴部２２の内壁に溶接によって固定されて、主軸受４７を支持している。端板部１９ａは、副軸受１９に支持されている。なお、本実施例は端板部１９ａをボルト等で固定されているが、胴部２２に溶接で固定しても構わない。 The end plate portion 48 a is fixed to the inner wall of the body portion 22 by welding and supports the main bearing 47. The end plate portion 19 a is supported by the sub bearing 19. In the present embodiment, the end plate portion 19a is fixed with a bolt or the like, but may be fixed to the body portion 22 by welding.

各圧縮要素１ａと１ｂは、次のように構成されている。低圧圧縮要素１ｂは、副軸受１９と、円筒状のシリンダ５０ａと、偏心部４６ａの外周に嵌め合わされた円筒状のローラ５１ａと、中間仕切板４９とによって構成され、これらに囲まれた空間が圧縮室２３ａとなる。また、高圧圧縮要素１ａは、主軸受４７と、円筒状のシリンダ５０ｂと、偏心部４６ｂの外周に嵌め合わされた円筒状のローラ５１ｂと、中間仕切板４９とによって構成され、これらに囲まれた空間が圧縮室２３ｂとなる。これらの圧縮室２３ａ、２３ｂは、コイルバネのような付勢力付与手段に連結された平板状のベーン（図示せず）が、偏心部４６ａ、４６ｂの偏心運動に合わせて回転するローラ５１ａ、５１ｂの外周上を接触しながら進退運動することにより、圧縮室２３ａ、２３ｂを圧縮空間と吸込み空間に分割する。 Each compression element 1a and 1b is comprised as follows. The low-pressure compression element 1b includes a sub bearing 19, a cylindrical cylinder 50a, a cylindrical roller 51a fitted on the outer periphery of the eccentric portion 46a, and an intermediate partition plate 49, and a space surrounded by these is formed. It becomes the compression chamber 23a. The high-pressure compression element 1a includes a main bearing 47, a cylindrical cylinder 50b, a cylindrical roller 51b fitted to the outer periphery of the eccentric portion 46b, and an intermediate partition plate 49, and is surrounded by these. The space becomes the compression chamber 23b. These compression chambers 23a and 23b are made up of rollers 51a and 51b in which flat vanes (not shown) connected to biasing force applying means such as coil springs rotate in accordance with the eccentric motion of the eccentric portions 46a and 46b. The compression chambers 23a and 23b are divided into a compression space and a suction space by moving forward and backward while contacting the outer periphery.

圧縮要素１ａ、１ｂは、偏心部４６ａ、４６ｂが偏心回転することでローラ５１ａ、５１ｂを駆動する。 The compression elements 1a and 1b drive the rollers 51a and 51b as the eccentric portions 46a and 46b rotate eccentrically.

図８に示すように偏心部４６ａと偏心部４６bは位相が180°異なり、圧縮要素１ａ、１ｂの圧縮工程の位相差は180°である。すなわち２つの圧縮要素の圧縮工程は逆位相となっている。 As shown in FIG. 8, the eccentric portion 46a and the eccentric portion 46b have a phase difference of 180 °, and the phase difference in the compression process of the compression elements 1a and 1b is 180 °. That is, the compression process of the two compression elements is in opposite phase.

作動流体であるガス冷媒の流れを、図８の矢印で表す。配管３１を通って供給される低圧Psのガス冷媒は、配管３１と接続する吸入口２５aより低圧用圧縮要素２０a内に吸入され、ローラ５１aが偏心回転することにより中間圧Pmまで圧縮される。圧縮室２３ａ内の圧力が予め設定された圧力になると開口する吐出弁２８aが中間圧Pmで開口すると、中間圧Pmとなったガス冷媒が、吐出口２６aと連通する吐出空間３３に吐出される。この吐出空間３３は、副軸受１９とカバー３５とにより密閉容器１３内の密閉空間２９と隔離された空間であり、その内部圧力は基本的には中間圧Pmとなる。中間流路３０は吐出空間３３と吸入口２５bを連通する流路であり、一部密閉容器４０外で略Ｕ字状に形成されている。吐出空間３３と中間流路３０、及び吸入口２５bからなる一つの連通した空間は、密閉容器１３と隔てられ内部圧力が中間圧Pmの中間空間３２（図１中、点線で囲われている部分）である。したがって、吐出弁２８ａが開口した吐出口２６ａから吐出された圧力Ｐｍのガス冷媒は、吐出空間３３に吐出された後、中間流路３０を通って、高圧圧力要素２０ｂの圧力室２３ｂと連通する吸入口２５ｂに至る。 The flow of the gas refrigerant that is the working fluid is represented by an arrow in FIG. The low-pressure Ps gas refrigerant supplied through the pipe 31 is sucked into the low-pressure compression element 20a from the suction port 25a connected to the pipe 31, and is compressed to the intermediate pressure Pm by the eccentric rotation of the roller 51a. When the discharge valve 28a that opens when the pressure in the compression chamber 23a reaches a preset pressure opens at the intermediate pressure Pm, the gas refrigerant that has reached the intermediate pressure Pm is discharged into the discharge space 33 that communicates with the discharge port 26a. . The discharge space 33 is a space that is isolated from the sealed space 29 in the sealed container 13 by the auxiliary bearing 19 and the cover 35, and the internal pressure thereof is basically the intermediate pressure Pm. The intermediate flow path 30 is a flow path that communicates the discharge space 33 and the suction port 25b, and is partially formed outside the sealed container 40 in a substantially U shape. One communicating space composed of the discharge space 33, the intermediate flow path 30, and the suction port 25b is separated from the hermetic container 13 and is an intermediate space 32 (indicated by a dotted line in FIG. 1) having an internal pressure Pm. ). Therefore, the gas refrigerant having the pressure Pm discharged from the discharge port 26a opened by the discharge valve 28a is discharged to the discharge space 33, and then communicates with the pressure chamber 23b of the high-pressure element 20b through the intermediate flow path 30. It reaches the suction port 25b.

次に、中間流路３０を通過して吸入口２５ｂより高圧用圧縮要素１ａ内に吸入された中間圧Pmのガス冷媒は、ローラ５１ｂが公転することにより高圧Pdまで圧縮される。圧縮室２３ｂ内の圧力が予め設定された圧力になると開口する吐出弁２８ｂが高圧Pdで開口すると、ガス冷媒は吐出口２６bから密閉容器４１の内部空間である密閉空間２９に吐出される。この密閉空間２９に吐出されたガス冷媒は、電動機１４の隙間を通過して吐出管２７より吐出される。 Next, the gas refrigerant having the intermediate pressure Pm passing through the intermediate flow path 30 and sucked into the high pressure compression element 1a from the suction port 25b is compressed to the high pressure Pd by the revolution of the roller 51b. When the discharge valve 28b that opens when the pressure in the compression chamber 23b reaches a preset pressure opens with high pressure Pd, the gas refrigerant is discharged from the discharge port 26b to the sealed space 29 that is the internal space of the sealed container 41. The gas refrigerant discharged into the sealed space 29 passes through the gap of the electric motor 14 and is discharged from the discharge pipe 27.

そして、中間流路３０の低圧用圧縮要素１ｂの吐出部には低段側吐出温度センサ８が、中間流路３０の高圧用圧縮要素１ａの吸込部には後段側吸込温度センサ７が設けられている。また、中間流路３０の低段側吐出温度センサ８と後段側吸込温度センサ７との間の流路には、気液分離器４に接続されたインジェクション配管１１が接続されている。すなわち、中間流路３０とインジェクション配管１１の接続部の冷媒流れ方向上流の中間流路３０に低段側吐出温度センサ８が下流の中間流路３０に高段側吸込温度センサ７が設けられることとなる。 A low-stage discharge temperature sensor 8 is provided at the discharge portion of the low-pressure compression element 1 b of the intermediate flow path 30, and a rear-stage suction temperature sensor 7 is provided at the suction portion of the high-pressure compression element 1 a of the intermediate flow path 30. ing. An injection pipe 11 connected to the gas-liquid separator 4 is connected to a flow path between the low-stage discharge temperature sensor 8 and the rear-stage suction temperature sensor 7 in the intermediate flow path 30. That is, the low-stage side discharge temperature sensor 8 is provided in the intermediate flow path 30 upstream in the refrigerant flow direction of the connection portion between the intermediate flow path 30 and the injection pipe 11, and the high-stage suction temperature sensor 7 is provided in the downstream intermediate flow path 30. It becomes.

本実施例では、低段側吐出温度センサ８と後段側吸込温度センサ７の温度差を利用して、インジェクション配管１１からインジェクションされる冷媒がガス冷媒であるのか、液が混ざっているのかを判断する。すなわち、インジェクション配管１１からの冷媒は上流側の電動膨張弁によって膨張した後の冷媒であるので、低温となっており、特に液冷媒が混合した冷媒が中間流路３０に流入すると、低圧用圧縮要素１ｂからのガス冷媒と混合した後の冷媒温度は低下する。すなわち、低段側吐出温度センサ８の出力値よりも後段側吸込温度センサ７の出力値の方が低い値を示すことを利用している。 In this embodiment, using the temperature difference between the low-stage discharge temperature sensor 8 and the rear-stage suction temperature sensor 7, it is determined whether the refrigerant injected from the injection pipe 11 is a gas refrigerant or a liquid is mixed. To do. That is, since the refrigerant from the injection pipe 11 is the refrigerant after being expanded by the electric expansion valve on the upstream side, the refrigerant is at a low temperature, and particularly when the refrigerant mixed with the liquid refrigerant flows into the intermediate flow path 30, the low-pressure compression is performed. The refrigerant temperature after mixing with the gas refrigerant from element 1b decreases. That is, the fact that the output value of the rear-stage suction temperature sensor 7 is lower than the output value of the lower-stage discharge temperature sensor 8 is used.

この原理を図３を用いて説明する。図３は図１に示した冷凍サイクルにおける下流側の第一電動膨張弁３の開度に対する（低段吐出温度）−（高段吸込温度）で、グラフ上部にはインジェクション冷媒の相状態を示している。第一電動膨張弁３を絞るほど（低段側吐出温度）−（高段側吸込温度）が大きくなる。これは下流側膨張弁を絞るほど、気液分離器４の圧力が増加して気液分離器４へ流入する冷媒の乾き度が大きくなるので、冷媒が静穏でなくなることで、気液分離性能が低下する。このため、インジェクション冷媒に液密度の大きい低温度の冷媒が多量に混入し、高段側入口冷媒温度が低段側吐出冷媒温度よりも低下するためである。 This principle will be described with reference to FIG. FIG. 3 shows (low stage discharge temperature) − (high stage suction temperature) with respect to the opening degree of the first electric expansion valve 3 on the downstream side in the refrigeration cycle shown in FIG. 1, and the upper part of the graph shows the phase state of the injection refrigerant. ing. As the first electric expansion valve 3 is throttled, (low stage discharge temperature) − (high stage suction temperature) increases. As the downstream side expansion valve is throttled, the pressure of the gas-liquid separator 4 increases, and the dryness of the refrigerant flowing into the gas-liquid separator 4 increases. Decreases. For this reason, a large amount of low-temperature refrigerant having a high liquid density is mixed in the injection refrigerant, and the high-stage inlet refrigerant temperature is lower than the low-stage discharge refrigerant temperature.

図２に戻って、（低段吐出温度）−（高段吸込温度）＞１℃ではないとき、すなわちガスインジェクションと判断された場合、ステップ１０６では下流側膨張弁を絞るように制御する。これは図４に示すように（低段側吐出温度）−（高段側吸込温度）とＣＯＰは（低段吐出温度）−（高段吸込温度）が１℃のときに最大ＣＯＰとなることが判明したため、（低段吐出温度）−（高段吸込温度）＞１℃では下流側電動膨張弁５の開度を絞りインジェクション圧力を上げて最大ＣＯＰに近づけるように制御する。 Returning to FIG. 2, when (low stage discharge temperature) − (high stage suction temperature)> 1 ° C. is not satisfied, that is, when it is determined that gas injection is performed, in step 106, control is performed to throttle the downstream side expansion valve. As shown in FIG. 4, this is the maximum COP when (low stage discharge temperature)-(high stage suction temperature) and COP (low stage discharge temperature)-(high stage suction temperature) is 1 ° C. Therefore, when (low stage discharge temperature) − (high stage suction temperature)> 1 ° C., the opening degree of the downstream side electric expansion valve 5 is controlled so as to be close to the maximum COP by increasing the injection pressure.

ここで（低段吐出温度）−（高段吸込温度）が略１℃のとき最大にＣＯＰとなるのは、インジェクション圧力が低いと二段圧縮機１の低段吐出圧力との差圧が小さくなり、インジェクション量が低下するためであると考えられる。また、インジェクション圧力が高いとＣＯＰが低下してしまう理由は、前述の通りインジェクション冷媒に液密度の大きい冷媒が圧縮機に戻ってしまうため蒸発器に循環する冷媒量が低下するためであると考えられる。 Here, when (low stage discharge temperature) − (high stage suction temperature) is approximately 1 ° C., the maximum COP is that when the injection pressure is low, the differential pressure from the low stage discharge pressure of the two-stage compressor 1 is small. This is considered to be because the injection amount decreases. In addition, the reason why the COP decreases when the injection pressure is high is considered to be because the refrigerant having a high liquid density returns to the compressor as the injection refrigerant and the amount of refrigerant circulating to the evaporator decreases. It is done.

しかし、若干の液冷媒混入は圧縮機の冷却作用があり、最大ＣＯＰはこれらの影響度によって定まり、本実施例では（低段側吐出温度）−（高段側吸込温度）＝１℃の場合が最大ＣＯＰとなることを前提に制御をかけている。 However, mixing of a small amount of liquid refrigerant has the effect of cooling the compressor, and the maximum COP is determined by the degree of influence. In this embodiment, (low stage side discharge temperature) − (high stage side suction temperature) = 1 ° C. Is controlled on the assumption that becomes the maximum COP.

図２に戻って、ステップ１０５を満足する場合、ステップ１１１に進む。ステップ１１１において、（低段吐出温度）−（高段吸込温度）＞１５℃の場合はかなり多量の液が含まれたインジェクションが行われていると判断し、電動膨張弁３、５による制御を諦め二方弁１２を閉じてインジェクションを中断する（ステップ１１２）。このようにかなり多量の液が含まれたインジェクションが行われた場合にインジェクションを中断する理由は、インジェクション冷媒の液混入率が高くなると、高段側圧縮機で液圧縮が起こり、液圧縮は圧縮機の破損や騒音の原因となるので防ぐ必要があるためである。 Returning to FIG. 2, if step 105 is satisfied, the process proceeds to step 111. In step 111, when (low stage discharge temperature) − (high stage suction temperature)> 15 ° C., it is judged that injection containing a considerably large amount of liquid is being performed, and control by the electric expansion valves 3 and 5 is performed. The two-way valve 12 is closed and the injection is interrupted (step 112). The reason for interrupting the injection when an injection containing such a large amount of liquid is performed is that when the liquid mixture ratio of the injection refrigerant increases, liquid compression occurs in the high stage compressor, and the liquid compression is compressed. This is because it is necessary to prevent damage to the machine and noise.

そして下流弁である第一電動膨張弁３を大幅に開けてインジェクション圧力を下げて気液分離が行われやすい状態とする（ステップ１１３）。そして、ステップ１０３に戻り、二方弁１２を開けてインジェクションを再開する。 Then, the first electric expansion valve 3, which is a downstream valve, is greatly opened to lower the injection pressure so that gas-liquid separation is easily performed (step 113). Then, returning to step 103, the two-way valve 12 is opened and the injection is resumed.

ステップ１１１で（低段側吐出温度）−（高段側吸込温度）＞１５℃で無い場合、すなわち、温度差が１℃から１５℃の場合は、悪影響の少ない液混入インジェクションであると判断して、下流側電動膨張弁（ここでは第一電動膨張弁３）を開け、ややインジェクション圧力を下げるようにしている（ステップ１１４）。 If (low stage side discharge temperature) − (high stage side suction temperature)> 15 ° C. is not satisfied in step 111, that is, if the temperature difference is 1 ° C. to 15 ° C., it is determined that the liquid injection has little adverse effect. Thus, the downstream electric expansion valve (here, the first electric expansion valve 3) is opened to slightly reduce the injection pressure (step 114).

ステップ１０７〜１０９は、上流側の膨張弁である第二電動膨張弁５の制御に関するもので、高段側吐出温度が別途定める目標高段側吐出温度になるように制御する。 Steps 107 to 109 relate to the control of the second electric expansion valve 5 which is the upstream expansion valve, and control is performed so that the high stage discharge temperature becomes a separately determined target high stage discharge temperature.

この理由は、図５に示すように、上流側電動弁開度は、開度を変化させても（低段側吐出温度）−（高段側吸込温度）への影響は小さく、インジェクション冷媒の相状態への影響は小さい。しかし、図６に示すように上流側電動膨張弁開度は高段側吐出温度に影響しており、しかも高段側吐出温度はＣＯＰに影響している。そしてこのＣＯＰは、図示のようにピーク値を持つことから、上流側電動膨張弁の開度には適正値がある。 The reason for this is that, as shown in FIG. 5, the upstream side motor valve opening degree has little influence on (low stage side discharge temperature) − (high stage side suction temperature) even if the opening degree is changed. The effect on the phase state is small. However, as shown in FIG. 6, the upstream electric expansion valve opening degree affects the high stage discharge temperature, and the high stage discharge temperature affects the COP. Since this COP has a peak value as shown in the figure, the opening degree of the upstream electric expansion valve has an appropriate value.

なお、高段側圧縮機温度制御（ステップ１０８〜１１０）をインジェクション量制御（ステップ１０５，１０６，１１１，１１２，１１３，１１４）適正化後に行っている理由は、多量の液がインジェクションされることで圧縮機が冷却され高段側吐出温度が低下した時に、上流側電動膨張弁３での減圧量が不十分と誤判定してしまうことを防ぐためである。 The reason why the high-stage compressor temperature control (steps 108 to 110) is performed after the injection amount control (steps 105, 106, 111, 112, 113, 114) is optimized is that a large amount of liquid is injected. This is to prevent erroneous determination that the amount of pressure reduction at the upstream side electric expansion valve 3 is insufficient when the compressor is cooled and the high stage discharge temperature is lowered.

ところで、本実施例ではステップ１０４で低段側吐出温度を検出し、ステップ１０５で液混合インジェクションか否か、あるいは液混合量の割合が最適値か否かを判定しているが、その低段側吐出温度を検出値ではなく、圧縮機回転数、高段側吐出温度、外気温度、室内温度、凝縮温度、蒸発温度、ファン回転数などの運転状態を検出、演算して定めても良い。 In this embodiment, the lower stage discharge temperature is detected in step 104, and it is determined in step 105 whether or not the liquid mixing injection is performed, or whether or not the ratio of the liquid mixing amount is the optimum value. The side discharge temperature may be determined by detecting and calculating the operation state such as the compressor rotation speed, the high stage discharge temperature, the outside air temperature, the indoor temperature, the condensing temperature, the evaporation temperature, and the fan rotation speed instead of the detected value.

例えば、冷房運転時の低段側吐出温度が、下流側電動膨張弁が適正に制御されている場合に圧縮機回転数と外気温度によって、ほぼ一意的に決まる。これらの関係を予め記憶しておき、検出された圧縮機回転数と外気温度によって低段側吐出温度を与えることができる。すなわち、図７に示すように、圧縮機回転数と低段側吐出温度は外気温度をパラメータとして関係付けられ、これらの値を予め演算装置１０内の記憶手段に格納しておき、検出された圧縮機回転数と外気温度から低段側吐出温度を求めることができる。
この場合、低段側吐出温度検出センサが不要であるので、安価な空気調和装置を提供できる。また（低段側吐出温度）−（１℃）を、目標高段側吸込温度として、ステップ１０５の処理を（目標高段側吸込温度）＞（高段側吸込温度）として行ってもよい。この場合演算手段の簡略化が図ることができる。 For example, the lower stage discharge temperature during the cooling operation is uniquely determined by the compressor speed and the outside air temperature when the downstream electric expansion valve is properly controlled. These relationships are stored in advance, and the low-stage discharge temperature can be given by the detected compressor rotation speed and outside air temperature. That is, as shown in FIG. 7, the compressor rotation speed and the lower stage discharge temperature are related with the outside air temperature as a parameter, and these values are stored in advance in the storage means in the arithmetic unit 10 and detected. The lower stage discharge temperature can be obtained from the compressor rotation speed and the outside air temperature.
In this case, since a low-stage discharge temperature detection sensor is unnecessary, an inexpensive air conditioner can be provided. Alternatively, (low stage side discharge temperature) − (1 ° C.) may be set as the target high stage side suction temperature, and the process of step 105 may be performed as (target high stage side suction temperature)> (high stage side suction temperature). In this case, the calculation means can be simplified.

図２において、ステップ１０７で後段側圧縮機吐出温度センサ９によって検出した後段側圧縮機吐出温度が、目標値より高ければ（ステップ１０８）、ステップ１１０にて上流側膨張弁を開けてＣＯＰが高くなる方向に制御し、目標値より低ければステップ１０９にて上流側膨張弁を絞ることでＣＯＰが高くなる方向に制御する。 In FIG. 2, if the downstream compressor discharge temperature detected by the downstream compressor discharge temperature sensor 9 in step 107 is higher than the target value (step 108), the upstream expansion valve is opened in step 110 and the COP is high. If it is lower than the target value, in step 109, the upstream expansion valve is throttled so as to increase the COP.

以上の説明から把握されるように、本実施例において、高段側吸込温度センサ７を設けることで、下流側減圧手段の減圧量を、高段側吸込温度と基準高段側吸込温度の差、あるいは低段側吐出温度と高段側吸込温度の差に基づいて定めること等の制御が可能となった。これによって、減圧量調整手段の個体差やゴミなどの堆積による抵抗値の変化があった場合でもでも最適に制御できるという効果を有する。 As can be understood from the above explanation, in this embodiment, by providing the high stage suction temperature sensor 7, the pressure reduction amount of the downstream decompression means is determined by the difference between the high stage suction temperature and the reference high stage suction temperature. Alternatively, control based on the difference between the low-stage discharge temperature and the high-stage suction temperature can be performed. As a result, there is an effect that optimal control can be performed even when there is a change in resistance value due to individual differences in the pressure reducing amount adjusting means or accumulation of dust or the like.

本発明の一実施例にかかる空気調和装置の冷凍サイクル図。The refrigeration cycle figure of the air conditioning apparatus concerning one Example of this invention. 本発明の一実施例にかかる制御のフローチャート。The flowchart of the control concerning one Example of this invention. 下流側膨張弁開度と圧縮機温度の関係を説明する図。The figure explaining the relationship between a downstream expansion valve opening degree and compressor temperature. 圧縮機温度とＣＯＰの関係を説明する図。The figure explaining the relationship between compressor temperature and COP. 膨張弁開度と圧縮機温度の関係を説明する図。The figure explaining the relationship between an expansion valve opening degree and compressor temperature. 上流側膨張弁開度とＣＯＰの関係を説明する図。The figure explaining the relationship between an upstream expansion valve opening degree and COP. 圧縮機回転数と圧縮機温度の関係を説明する図。The figure explaining the relationship between compressor rotation speed and compressor temperature. 本発明の一実施例に係る二段圧縮機の縦断面図。The longitudinal cross-sectional view of the two-stage compressor which concerns on one Example of this invention.

符号の説明Explanation of symbols

１…二段圧縮機、２…室外熱交換器、３…第一電動膨張弁、４…気液分離器、５…第二電動膨張弁、６…室内熱交換器である、７…高段側吸込温度センサ、８…低段側吐出温度センサ、９…高段側吐出温度センサ、１０…演算装置、１１…インジェクション配管、１２…二方弁、１３…室外送風ファン、１４…室内送風ファン。
DESCRIPTION OF SYMBOLS 1 ... Two-stage compressor, 2 ... Outdoor heat exchanger, 3 ... First electric expansion valve, 4 ... Gas-liquid separator, 5 ... Second electric expansion valve, 6 ... Indoor heat exchanger, 7 ... High stage Side suction temperature sensor, 8 ... Low stage discharge temperature sensor, 9 ... High stage discharge temperature sensor, 10 ... Calculation device, 11 ... Injection piping, 12 ... Two-way valve, 13 ... Outdoor fan, 14 ... Indoor fan .

Claims

低圧側圧縮部と高圧側圧縮部を有する二段圧縮機と、この二段圧縮機に接続された第二熱交換器と、この第二熱交換器に接続され開度の調節が可能な第二減圧手段と、この第二減圧手段に接続された気液分離器と、この気液分離器に接続され開度の調節が可能な第一減圧手段と、一方がこの第一減圧手段に接続され、他方が前記二段圧縮機に接続された第一熱交換器とを有する冷凍サイクルと、前記気液分離器と前記圧縮機の低圧側圧縮部の冷媒吐出部と高圧側圧縮機部の冷媒吸込部との間の中間冷媒流路とを接続するインジェクション配管とを備えた空気調和装置において、前記中間冷媒流路と前記インジェクション配管との接続部よりも高段側圧縮部よりの吸込部分に高段側吸込温度検出手段を設けた空気調和装置。 A two-stage compressor having a low-pressure side compression section and a high-pressure side compression section, a second heat exchanger connected to the two-stage compressor, and a second heat exchanger connected to the second heat exchanger capable of adjusting the opening degree. Two pressure reducing means, a gas-liquid separator connected to the second pressure reducing means, a first pressure reducing means connected to the gas-liquid separator and capable of adjusting the opening degree, one of which is connected to the first pressure reducing means A refrigeration cycle having a first heat exchanger connected to the two-stage compressor, the gas-liquid separator, a refrigerant discharge portion of a low pressure side compression portion of the compressor, and a high pressure side compressor portion In an air conditioner including an injection pipe that connects an intermediate refrigerant flow path between the refrigerant suction section and a suction section from a higher-stage compression section than a connection section between the intermediate refrigerant flow path and the injection pipe An air conditioner provided with high-stage suction temperature detecting means.

低圧側圧縮部と高圧側圧縮部を有し、この低圧側圧縮部の冷媒吐出部とこの高圧側圧縮部の冷媒吸込部との間に中間冷媒流路とを有する二段圧縮機と、この二段圧縮機に接続された第二熱交換器と、この第二熱交換器に接続され開度の調節が可能な第二減圧手段と、この第二減圧手段に接続された気液分離器と、この気液分離器に接続され開度の調節が可能な第一減圧手段と、一方がこの第一減圧手段に接続され、他方が前記二段圧縮機に接続された第一熱交換器とを有する冷凍サイクルと、前記気液分離器と前記中間冷媒流路とを接続するインジェクション配管とを備えた空気調和装置において、前記中間冷媒流路は前記二段圧縮機の密閉容器外に露出した冷媒配管を有し、前記インジェクション配管と前記中間冷媒流路の密閉容器外に露出した冷媒配管との接続部よりも冷媒流れ方向下流の前記密閉容器外に露出した冷媒配管に高段側吸込温度検出手段を設けた空気調和装置。 A two-stage compressor having a low pressure side compression portion and a high pressure side compression portion, and having an intermediate refrigerant flow path between the refrigerant discharge portion of the low pressure side compression portion and the refrigerant suction portion of the high pressure side compression portion, A second heat exchanger connected to the two-stage compressor, a second pressure reducing means connected to the second heat exchanger and capable of adjusting an opening degree, and a gas-liquid separator connected to the second pressure reducing means A first pressure reducing means connected to the gas-liquid separator and capable of adjusting the opening degree, and a first heat exchanger in which one is connected to the first pressure reducing means and the other is connected to the two-stage compressor And an injection pipe that connects the gas-liquid separator and the intermediate refrigerant flow path, wherein the intermediate refrigerant flow path is exposed outside the sealed container of the two-stage compressor. Refrigerant pipes that are exposed outside the sealed container of the injection pipe and the intermediate refrigerant flow path. Refrigerant piping connecting portion air conditioner provided with a high-stage suction temperature detecting means to the refrigerant pipe exposed outside the closed container of the refrigerant flow direction downstream from.

請求項１または２において、前記高段側吸込温度検出手段の出力に基いて、下流側減圧手段となる前記第１の減圧手段の減圧量を調節するようにした空気調和装置。 The air conditioner according to claim 1 or 2, wherein the pressure reduction amount of the first pressure reducing means, which is the downstream pressure reducing means, is adjusted based on the output of the high stage suction temperature detecting means.

低圧側圧縮部と高圧側圧縮部を有する二段圧縮機と、この二段圧縮機に接続された冷媒流れ方向切換え手段と、この冷媒流れ方向切換え手段に接続された室内熱交換器と、この室内熱交換器に接続され開度の調節が可能な第二減圧手段と、この第二減圧手段に接続された気液分離器と、この気液分離器に接続され開度の調節が可能な第一減圧手段と、一方がこの第一減圧手段に接続され、他方が前記冷媒流れ方向切換え手段に接続された室外熱交換器とを有する冷凍サイクルと、前記気液分離器と前記圧縮機の低圧側圧縮部の冷媒吐出部と高圧側圧縮機部の冷媒吸込部との間の中間冷媒流路とを接続するインジェクション配管とを備えた空気調和装置において、前記中間冷媒流路と前記インジェクション配管との接続部よりも高段側圧縮部よりの吸込部分に高段側吸込温度検出手段を設けた空気調和装置。 A two-stage compressor having a low-pressure side compression section and a high-pressure side compression section, a refrigerant flow direction switching means connected to the two-stage compressor, an indoor heat exchanger connected to the refrigerant flow direction switching means, and A second decompression means connected to the indoor heat exchanger and capable of adjusting the opening, a gas-liquid separator connected to the second decompression means, and connected to the gas-liquid separator and capable of adjusting the opening. A refrigeration cycle having a first decompression means, an outdoor heat exchanger connected to the first decompression means and the other connected to the refrigerant flow direction switching means, the gas-liquid separator, and the compressor In the air conditioner comprising an injection pipe for connecting an intermediate refrigerant flow path between the refrigerant discharge part of the low pressure side compression part and the refrigerant suction part of the high pressure side compressor part, the intermediate refrigerant flow path and the injection pipe Higher compression part than the connection part An air conditioning apparatus provided with a high-stage suction temperature detecting means to the suction portion of the.

低圧側圧縮部と高圧側圧縮部を有し、この低圧側圧縮部の冷媒吐出部とこの高圧側圧縮部の冷媒吸込部との間に中間冷媒流路とを有する二段圧縮機と、この二段圧縮機に接続された冷媒流れ方向切換え手段と、この冷媒流れ方向切換え手段に接続された室内熱交換器と、この室内熱交換器に接続され開度の調節が可能な第二減圧手段と、この第二減圧手段に接続された気液分離器と、この気液分離器に接続され開度の調節が可能な第一減圧手段と、一方がこの第一減圧手段に接続され、他方が前記冷媒流れ方向切換え手段に接続された室外熱交換器とを有する冷凍サイクルと、前記気液分離器と前記中間冷媒流路とを接続するインジェクション配管とを備えた空気調和装置において、前記インジェクション配管と前記中間冷媒流路の密閉容器外に露出した冷媒配管との接続部よりも冷媒流れ方向下流の前記密閉容器外に露出した冷媒配管に高段側吸込温度検出手段を設けた空気調和装置。 A two-stage compressor having a low pressure side compression portion and a high pressure side compression portion, and having an intermediate refrigerant flow path between the refrigerant discharge portion of the low pressure side compression portion and the refrigerant suction portion of the high pressure side compression portion, Refrigerant flow direction switching means connected to the two-stage compressor, an indoor heat exchanger connected to the refrigerant flow direction switching means, and a second pressure reducing means connected to the indoor heat exchanger and capable of adjusting the opening degree A gas-liquid separator connected to the second pressure reducing means, a first pressure reducing means connected to the gas-liquid separator and capable of adjusting the opening degree, one connected to the first pressure reducing means, and the other In the air conditioning apparatus, comprising: a refrigeration cycle having an outdoor heat exchanger connected to the refrigerant flow direction switching means; and an injection pipe connecting the gas-liquid separator and the intermediate refrigerant flow path. Airtight container for piping and intermediate refrigerant flow path An air conditioning apparatus provided with a high-stage suction temperature detecting means to the refrigerant pipe exposed outside the closed container of the refrigerant flow direction downstream from the connecting portion of the refrigerant pipe which is exposed to.

請求項４または５において、前記高段側吸込温度検出手段の出力に基いて、下流側減圧手段となる前記第第一減圧手段若しくは前記第二減圧手段の減圧量を調節するようにした空気調和装置。 6. The air conditioner according to claim 4 or 5, wherein the pressure reduction amount of the first pressure reducing means or the second pressure reducing means serving as the downstream pressure reducing means is adjusted based on the output of the high stage suction temperature detecting means. apparatus.

低圧側圧縮部と高圧側圧縮部を有し、この低圧側圧縮部の冷媒吐出部とこの高圧側圧縮部の冷媒吸込部との間に中間冷媒流路とを有する二段圧縮機と、この二段圧縮機に接続された第二熱交換器と、この第二熱交換器に接続され開度の調節が可能な第二減圧手段と、この第二減圧手段に接続された気液分離器と、この気液分離器に接続され開度の調節が可能な第一減圧手段と、一方がこの第一減圧手段に接続され、他方が前記二段圧縮機に接続された第一熱交換器とを有する冷凍サイクルと、前記気液分離器と前記中間冷媒流路とを接続するインジェクション配管とを備えた空気調和装置において、前記中間冷媒流路は前記二段圧縮機の密閉容器外に露出した冷媒配管を有し、前記インジェクション配管と前記中間冷媒流路の密閉容器外に露出した冷媒配管との接続部よりも冷媒流れ方向下流の前記密閉容器外に露出した冷媒配管に高段側吸込温度検出手段を、冷媒流れ方向上流の前記密閉容器外に露出した冷媒配管に低段側吐出温度検出手段を設けた空気調和装置。 A two-stage compressor having a low pressure side compression portion and a high pressure side compression portion, and having an intermediate refrigerant flow path between the refrigerant discharge portion of the low pressure side compression portion and the refrigerant suction portion of the high pressure side compression portion, A second heat exchanger connected to the two-stage compressor, a second pressure reducing means connected to the second heat exchanger and capable of adjusting an opening degree, and a gas-liquid separator connected to the second pressure reducing means A first pressure reducing means connected to the gas-liquid separator and capable of adjusting the opening degree, and a first heat exchanger in which one is connected to the first pressure reducing means and the other is connected to the two-stage compressor And an injection pipe that connects the gas-liquid separator and the intermediate refrigerant flow path, wherein the intermediate refrigerant flow path is exposed outside the sealed container of the two-stage compressor. Refrigerant pipes that are exposed outside the sealed container of the injection pipe and the intermediate refrigerant flow path. A higher-stage suction temperature detecting means is provided in the refrigerant pipe exposed outside the sealed container downstream in the refrigerant flow direction than the connection with the refrigerant pipe, and a lower stage is provided in the refrigerant pipe exposed outside the sealed container upstream in the refrigerant flow direction. An air conditioner provided with side discharge temperature detection means.

低圧側圧縮部と高圧側圧縮部を有し、この低圧側圧縮部の冷媒吐出部とこの高圧側圧縮部の冷媒吸込部との間に中間冷媒流路とを有する二段圧縮機と、この二段圧縮機に接続された冷媒流れ方向切換え手段と、この冷媒流れ方向切換え手段に接続された室内熱交換器と、この室内熱交換器に接続され開度の調節が可能な第二減圧手段と、この第二減圧手段に接続された気液分離器と、この気液分離器に接続され開度の調節が可能な第一減圧手段と、一方がこの第一減圧手段に接続され、他方が前記冷媒流れ方向切換え手段に接続された室外熱交換器とを有する冷凍サイクルと、前記気液分離器と前記中間冷媒流路とを接続するインジェクション配管とを備えた空気調和装置において、前記インジェクション配管と前記中間冷媒流路の密閉容器外に露出した冷媒配管との接続部よりも冷媒流れ方向下流の前記密閉容器外に露出した冷媒配管に高段側吸込温度検出手段を、冷媒流れ方向上流の前記密閉容器外に露出した冷媒配管に低段側吐出温度検出手段を設けた空気調和装置。 A two-stage compressor having a low pressure side compression portion and a high pressure side compression portion, and having an intermediate refrigerant flow path between the refrigerant discharge portion of the low pressure side compression portion and the refrigerant suction portion of the high pressure side compression portion, Refrigerant flow direction switching means connected to the two-stage compressor, an indoor heat exchanger connected to the refrigerant flow direction switching means, and a second pressure reducing means connected to the indoor heat exchanger and capable of adjusting the opening degree A gas-liquid separator connected to the second pressure reducing means, a first pressure reducing means connected to the gas-liquid separator and capable of adjusting the opening degree, one connected to the first pressure reducing means, and the other In the air conditioning apparatus, comprising: a refrigeration cycle having an outdoor heat exchanger connected to the refrigerant flow direction switching means; and an injection pipe connecting the gas-liquid separator and the intermediate refrigerant flow path. Airtight container for piping and intermediate refrigerant flow path The refrigerant pipe exposed to the outside of the sealed container downstream in the refrigerant flow direction with respect to the connection with the exposed refrigerant pipe is connected to the refrigerant pipe exposed to the outside of the sealed container upstream in the refrigerant flow direction. An air conditioner provided with low-stage discharge temperature detection means.

請求項７または８において、前記高段側吸込温度検出手段及び前記低段側吐出温度検出手段の出力に基いて、前記第一減圧手段及び前記第二減圧手段のうち冷媒流れ方向下流側となる減圧手段の減圧量を調整するようにした空気調和装置。
9. The refrigerant flow direction downstream of the first pressure reducing means and the second pressure reducing means based on outputs of the high stage suction temperature detecting means and the low stage discharge temperature detecting means according to claim 7. An air conditioner adapted to adjust the amount of decompression of the decompression means.