JP2013015264A - Air conditioner - Google Patents

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JP2013015264A
JP2013015264A JP2011148471A JP2011148471A JP2013015264A JP 2013015264 A JP2013015264 A JP 2013015264A JP 2011148471 A JP2011148471 A JP 2011148471A JP 2011148471 A JP2011148471 A JP 2011148471A JP 2013015264 A JP2013015264 A JP 2013015264A
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refrigerant
compressor
heat exchanger
pressure
flow path
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JP5409715B2 (en
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Koyu Tanaka
航祐 田中
Koji Yamashita
浩司 山下
Suguru Hatomura
傑 鳩村
Shinichi Wakamoto
慎一 若本
Naofumi Takenaka
直史 竹中
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Mitsubishi Electric Corp
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Abstract

PROBLEM TO BE SOLVED: To provide an air conditioner capable of achieving a highly efficient operation as a whole even under various operation conditions.SOLUTION: The air conditioner includes a main refrigerant circuit configured by annularly connecting a compressor 3 having an injection port serving as a refrigerant passage in the middle part of a compression process for compressing and discharging a sucked refrigerant, a four-way valve 4, a heat source side throttle device 11, a heat source side heat exchanger 12, a load side throttle device 8, and a load side heat exchanger 6, and one or more flow path switching refrigerant circuit 20 including a bypass throttle device 14a for reducing the pressure of a refrigerant branched from the main refrigerant circuit, an internal heat exchanger 9a for exchanging heat between a refrigerant passed through the bypass throttle device 14a and a refrigerant passed through the main refrigerant circuit and a flow path switching valve 16a for setting a flow path through which the refrigerant heat-exchanged by the internal heat exchanger 9a is supplied to one of the injection port or the suction side of the compressor.

Description

この発明は、冷媒間の熱交換を行う内部熱交換器を有する空気調和装置に関するものである。   The present invention relates to an air conditioner having an internal heat exchanger that performs heat exchange between refrigerants.

従来、例えば外気温度がマイナス１０℃となるような寒冷地において、圧縮機に吸入される冷媒の流量が外気の低下に伴って減少することになるために、暖房能力が低下してしまうことがある。そこで、冷媒を圧縮機にインジェクションすることによって十分な暖房能力を発揮できるようにした空気調和装置が存在する。このような空気調和装置では、圧縮機のインジェクションポートから冷媒を供給することによって、圧縮機室の冷媒密度を増加させ、冷媒循環量を増加させることで暖房能力の増大を行っている。   Conventionally, for example, in a cold district where the outside air temperature is minus 10 ° C., the flow rate of the refrigerant sucked into the compressor decreases as the outside air decreases, so that the heating capacity may decrease. is there. Thus, there is an air conditioner that can exhibit sufficient heating capacity by injecting refrigerant into the compressor. In such an air conditioner, the refrigerant density is supplied from the injection port of the compressor, thereby increasing the refrigerant density in the compressor chamber and increasing the refrigerant circulation amount, thereby increasing the heating capacity.

そのような空気調和装置として、「圧縮機、室内熱交換器、第１の減圧装置、室外熱交換器を環状に接続し、前記室内熱交換器から温熱を供給する空気調和装置において、前記室内熱交換器と前記第１の減圧装置との間の冷媒と、前記室外熱交換器と前記圧縮機との間の冷媒とを熱交換する第１の内部熱交換器と、前記室内熱交換器と前記第１の減圧装置との間の冷媒を、一部バイパスして前記圧縮機内の圧縮室にインジェクションするインジェクション回路と、該インジェクション回路に設けられたインジェクション用減圧装置と、該インジェクション用減圧装置で減圧された冷媒と前記室内熱交換器と前記第１の減圧装置との間の冷媒とを熱交換する第２の内部熱交換器とを備えた空気調和装置」が提案されている（たとえば、特許文献１参照）。   As such an air conditioner, “in an air conditioner in which a compressor, an indoor heat exchanger, a first pressure reducing device, an outdoor heat exchanger are connected in an annular shape and heated from the indoor heat exchanger is supplied, A first internal heat exchanger that exchanges heat between the refrigerant between the heat exchanger and the first pressure reducing device, and the refrigerant between the outdoor heat exchanger and the compressor; and the indoor heat exchanger. Injection circuit for partially bypassing the refrigerant between the first decompression device and the compression chamber in the compressor, the decompression device for injection provided in the injection circuit, and the decompression device for injection An air conditioner having a second internal heat exchanger that exchanges heat between the refrigerant depressurized in step (a) and the refrigerant between the indoor heat exchanger and the first decompression device has been proposed (for example, , Patent Literature Reference).

特開２００６−１１２７０８号公報（第７頁、第１図）JP 2006-112708 A (page 7, FIG. 1)

しかし、従来の空気調和装置には以下のような問題があった。例えば、特許文献１に記載の空気調和装置では、暖房運転時は、圧縮機の吸入側である低圧側において熱交換する第１の内部熱交換器において、冷却される熱交換量が大きくなる。このため、冷媒のエンタルピが圧縮機のインジェクションポート圧力の飽和液エンタルピ以下になる場合は、圧縮機のインジェクションポートに流れると熱交換する第２の内部熱交換器での熱交換量が低下し、蒸発器での冷却効果拡大の効果が十分に得られなくなる。このため、第２の内部熱交換器を有効に利用できず、成績効率（成績係数）であるＣＯＰの向上率が小さくなることがあった。   However, the conventional air conditioner has the following problems. For example, in the air conditioner described in Patent Literature 1, during the heating operation, the amount of heat exchange to be cooled is increased in the first internal heat exchanger that performs heat exchange on the low-pressure side that is the suction side of the compressor. For this reason, when the enthalpy of the refrigerant is equal to or lower than the saturated liquid enthalpy of the injection port pressure of the compressor, the amount of heat exchange in the second internal heat exchanger that exchanges heat when flowing into the injection port of the compressor is reduced, The effect of expanding the cooling effect in the evaporator cannot be obtained sufficiently. For this reason, the 2nd internal heat exchanger cannot be used effectively, and the improvement rate of COP which is a performance efficiency (performance coefficient) may become small.

また、冷房運転時に空調対象空間である室内空気温度が高い場合又は暖房運転時に外気温度が高い場合は、圧縮機の吸入側における圧力である低圧圧力が上昇し、これにともない、インジェクションポートにおける圧力が上昇する。その結果、インジェクションポートに流れる冷媒の飽和温度が上昇するため、内部熱交換器において、蒸発側となる冷媒における冷却効果拡大の効果が得られなくなることがあった。   Also, when the indoor air temperature, which is the air-conditioning target space during the cooling operation, is high or when the outside air temperature is high during the heating operation, the low-pressure pressure, which is the pressure on the suction side of the compressor, increases, and accordingly, the pressure at the injection port Rises. As a result, since the saturation temperature of the refrigerant flowing through the injection port increases, the effect of increasing the cooling effect of the refrigerant on the evaporation side may not be obtained in the internal heat exchanger.

そこで本発明は、かかる点に鑑みてなされたものであり、その目的は、様々な運転条件下でも、装置全体として高効率の運転を実現できる空気調和装置を提供することである。   Therefore, the present invention has been made in view of the above points, and an object of the present invention is to provide an air conditioner that can realize high-efficiency operation as a whole device even under various operating conditions.

上述の目的を達成するために、この発明は以下の手段を講じたものである。   In order to achieve the above object, the present invention takes the following measures.

本発明に係る空気調和装置は、吸入した冷媒を圧縮して吐出する圧縮行程の中間部分に冷媒通過口となるインジェクションポートを有する圧縮機、四方弁、熱源側絞り装置、熱源側熱交換器、負荷側絞り装置及び負荷側熱交換器を環状に接続して主冷媒回路を構成し、主冷媒回路から分岐した冷媒の減圧を行うバイパス絞り装置と、バイパス絞り装置を通過した冷媒と主冷媒回路を通過する冷媒との熱交換を行う内部熱交換器と、内部熱交換器が熱交換した冷媒をインジェクションポート又は圧縮機の吸入側のいずれかに流すための流路設定を行う流路切替手段とを有する１以上の流路切替冷媒回路をさらに備えるものである。   An air conditioner according to the present invention includes a compressor having an injection port serving as a refrigerant passage at an intermediate portion of a compression stroke for compressing and discharging sucked refrigerant, a four-way valve, a heat source side expansion device, a heat source side heat exchanger, A bypass throttle device configured to form a main refrigerant circuit by annularly connecting a load-side throttle device and a load-side heat exchanger and depressurizing the refrigerant branched from the main refrigerant circuit, and a refrigerant and main refrigerant circuit that have passed through the bypass throttle device An internal heat exchanger for exchanging heat with the refrigerant passing through the flow path, and a flow path switching means for setting the flow path for flowing the refrigerant heat exchanged by the internal heat exchanger to either the injection port or the suction side of the compressor And one or more flow path switching refrigerant circuits.

本発明によれば、流路切替手段を有し、冷房運転、暖房運転等の運転状態に応じて、圧縮機のインジェクションポートから冷媒を流入させるか圧縮機の吸入側に冷媒を流すかを選択することができるので、運転状態にかかわらず、高効率な運転を実現可能な空気調和装置を得ることができる。   According to the present invention, the flow path switching means is provided, and it is selected whether the refrigerant flows from the injection port of the compressor or the refrigerant flows to the suction side of the compressor according to the operation state such as the cooling operation and the heating operation. Therefore, it is possible to obtain an air conditioner capable of realizing highly efficient operation regardless of the operation state.

本発明の実施の形態１における空気調和装置１００の構成を示す図。The figure which shows the structure of the air conditioning apparatus 100 in Embodiment 1 of this invention. 本発明の実施の形態１における空気調和装置１００の暖房運転時で圧縮機３の吸入圧力が低い状態でインジェクションポートへの冷媒のバイパスを行っている状態のｐ−ｈ線図。The ph diagram of the state which is bypassing the refrigerant | coolant to an injection port in the state where the suction pressure of the compressor 3 is low at the time of heating operation of the air conditioning apparatus 100 in Embodiment 1 of this invention. 本発明の実施の形態１における空気調和装置１００の暖房運転時で圧縮機３の吸入圧力が高い状態でインジェクションポートへの冷媒のバイパスを行っている状態のｐ−ｈ線図。The ph diagram of the state which is performing the bypass of the refrigerant | coolant to the injection port in the state with the high suction pressure of the compressor 3 at the time of the heating operation of the air conditioning apparatus 100 in Embodiment 1 of this invention. 本発明の実施の形態１における空気調和装置の暖房運転時で圧縮機３の吸入圧力が高い状態で圧縮機３の吸入側に冷媒を流している状態のｐ−ｈ線図。The ph diagram of the state where the refrigerant is flowing on the suction side of compressor 3 in the state where the suction pressure of compressor 3 is high at the time of heating operation of the air harmony device in Embodiment 1 of the present invention. インジェクション圧力、圧縮機運転容量の大、小に対する、インジェクションバイパスと吸入バイパスのＣＯＰ向上率を表す概念図。The conceptual diagram showing the COP improvement rate of the injection bypass and the suction bypass with respect to the injection pressure and the compressor operating capacity large and small. 本発明の実施の形態１における空気調和装置１００の冷房運転時でインジェクションバイパスを行っている状態のｐ−ｈ線図。The ph diagram of the state which is performing the injection bypass at the time of air_conditionaing | cooling operation of the air conditioning apparatus 100 in Embodiment 1 of this invention. 本発明の実施の形態１における空気調和装置１００の暖房運転時の制御に係るフローチャート。The flowchart which concerns on control at the time of the heating operation of the air conditioning apparatus 100 in Embodiment 1 of this invention. 本発明の実施の形態１における空気調和装置１００の冷房運転時の制御に係るフローチャート。The flowchart which concerns on control at the time of air_conditionaing | cooling operation of the air conditioning apparatus 100 in Embodiment 1 of this invention. 本発明の実施の形態２における空気調和装置１００の構成を示す図。The figure which shows the structure of the air conditioning apparatus 100 in Embodiment 2 of this invention. 圧縮機３の運転容量が高いときのインジェクション内部熱交換器容量比率に対するＣＯＰ向上率を表す概念図。The conceptual diagram showing the COP improvement rate with respect to the injection internal heat exchanger capacity | capacitance ratio when the operating capacity of the compressor 3 is high. 圧縮機３の運転容量が低いときのインジェクション内部熱交換器容量比率に対するＣＯＰ向上率を表す概念図。The conceptual diagram showing the COP improvement rate with respect to the injection internal heat exchanger capacity | capacitance ratio when the operating capacity of the compressor 3 is low.

実施の形態１．
以下、本発明の実施の形態を図面に基づいて詳細に説明する。ここで、以下で説明する温度、圧力の高低については、特に絶対的な値との関係で高低等が定まっているものではなく、装置等における状態、動作等において相対的に定まる関係に基づいて表記しているものとする。また、機器等について、特に区別したり、特定したりする必要がない場合には、添字を省略して記載する場合もある。 Embodiment 1 FIG.
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Here, the levels of temperature and pressure described below are not particularly determined in relation to absolute values, but are based on relationships that are relatively determined in the state, operation, etc. of the device. It shall be written. In addition, when there is no need to distinguish or specify a device or the like, the suffix may be omitted.

図１は本発明に係る実施の形態１の空気調和装置１００の構成を示す図である。ここでは、冷凍サイクル装置の一例として、空気調和装置１００について説明する。図１において、室外機１及び室内機２が有する機器をガス管５及び液管７で配管接続して、冷媒を循環させる冷凍サイクル回路（冷媒回路）を構成する。特に、圧縮機３、四方弁４、室外熱交換器１２、熱源側絞り装置１１、負荷側絞り装置８、室内熱交換器６を配管接続して主となる冷媒回路（主冷媒回路）を構成する。   FIG. 1 is a diagram illustrating a configuration of an air-conditioning apparatus 100 according to Embodiment 1 of the present invention. Here, the air conditioning apparatus 100 will be described as an example of a refrigeration cycle apparatus. In FIG. 1, the apparatus which the outdoor unit 1 and the indoor unit 2 have are connected by piping with the gas pipe 5 and the liquid pipe 7, and the refrigerating cycle circuit (refrigerant circuit) which circulates a refrigerant | coolant is comprised. In particular, the compressor 3, the four-way valve 4, the outdoor heat exchanger 12, the heat source side expansion device 11, the load side expansion device 8, and the indoor heat exchanger 6 are connected to form a main refrigerant circuit (main refrigerant circuit). To do.

室外機１は、主冷媒回路のうち、圧縮機３、四方弁４、室外熱交換器１２、熱源側絞り装置１１を有している。圧縮機３は、吸入した冷媒に圧力を加えて吐出する（送り出す）。ここで、本実施の形態の圧縮機３は、インバータ回路（図示せず）により、計測制御装置１８の指示に基づいて駆動周波数を任意に変化することができる。このため、圧縮機３は、全体として吐出容量（単位時間あたりの冷媒の吐出量）と、その吐出容量に伴って能力を変化させることができるインバータ圧縮機となる。また、圧縮機３内の圧縮室（図示せず）において、圧縮行程の途中部分に、インジェクションバイパス配管１３ａからの冷媒を流入させるインジェクションポート（図示せず）を設けている。四方弁４は、計測制御装置１８の指示に基づいて、冷暖房の形態（モード）に対応した弁の切り替えを行い、冷媒の経路が切り替わるようにする。   The outdoor unit 1 includes a compressor 3, a four-way valve 4, an outdoor heat exchanger 12, and a heat source side expansion device 11 in the main refrigerant circuit. The compressor 3 applies pressure to the sucked refrigerant and discharges (sends out) it. Here, the compressor 3 of this Embodiment can change a drive frequency arbitrarily based on the instruction | indication of the measurement control apparatus 18 with an inverter circuit (not shown). For this reason, the compressor 3 becomes an inverter compressor which can change a capacity | capacitance with the discharge capacity | capacitance (discharge amount of the refrigerant | coolant per unit time) as a whole, and the discharge capacity. In addition, in a compression chamber (not shown) in the compressor 3, an injection port (not shown) through which the refrigerant from the injection bypass pipe 13a flows is provided in the middle of the compression stroke. The four-way valve 4 switches the valve corresponding to the cooling / heating mode (mode) based on an instruction from the measurement control device 18 so that the refrigerant path is switched.

室外熱交換器１２は冷媒と空気（室外の空気）との熱交換を行う。例えば、暖房運転時においては蒸発器として機能し、熱源側絞り装置１１を介して流入した冷媒と空気との熱交換を行い、冷媒を蒸発させ、気化させる。また、冷房運転時においては凝縮器として機能し、四方弁４側から流入した圧縮機３において圧縮された冷媒と空気との熱交換を行い、冷媒を凝縮して液化させる。例えば、室外熱交換器１２には、冷媒と空気との熱交換を効率よく行うため、空気を送るファン（図示せず）が設けられている。熱源側絞り装置１１は、例えば、暖房運転時において、計測制御装置１８の指示に基づいて開度を調整して冷媒を減圧等することができる電子膨張弁である。   The outdoor heat exchanger 12 performs heat exchange between the refrigerant and air (outdoor air). For example, during the heating operation, it functions as an evaporator, performs heat exchange between the refrigerant and the air that has flowed in through the heat source side expansion device 11, and evaporates and vaporizes the refrigerant. Further, during the cooling operation, it functions as a condenser, performs heat exchange between the refrigerant compressed in the compressor 3 flowing in from the four-way valve 4 side and air, and condenses and liquefies the refrigerant. For example, the outdoor heat exchanger 12 is provided with a fan (not shown) for sending air in order to efficiently exchange heat between the refrigerant and the air. The heat source side expansion device 11 is, for example, an electronic expansion valve that can adjust the opening degree based on an instruction from the measurement control device 18 to decompress the refrigerant during heating operation.

また、室外機１は、バイパス配管１７ａ、バイパス絞り装置１４ａ、インジェクションバイパス配管１３ａ、吸入バイパス配管１５ａ、流路切替弁１６ａを有し、主冷媒回路に対して流路切替冷媒回路２０を構成する。バイパス配管１７ａは、主冷媒回路から分岐した（バイパスした）冷媒を内部熱交換器９ａに流す配管である。バイパス絞り装置１４ａは、計測制御装置１８の指示に基づいて開度を調整して、流路切替冷媒回路２０を流れる冷媒の減圧、冷媒量の調整等することができる電子膨張弁である。内部熱交換器９ａは、主冷媒回路側を流れる冷媒と、バイパス絞り装置１４ａを通過して流路切替冷媒回路２０側を流れる冷媒との熱交換を行う。流路切替手段である流路切替弁１６ａは、内部熱交換器９ａを通過した冷媒を、インジェクションバイパス配管１３ａに通過させるか、吸入バイパス配管１５ａに通過させるかを切り替えて冷媒の流路設定を行う。インジェクションバイパス配管１３ａは、一端がインジェクションポートに接続しており、バイパスした冷媒をインジェクションポートに流す（インジェクションバイパスをする）ための配管である。また、吸入バイパス配管１５ａは、一端が圧縮機の吸入側（低圧側）に接続しており、バイパスした冷媒を圧縮機３の吸入側に流す（吸入バイパスをする）ための配管である。   The outdoor unit 1 includes a bypass pipe 17a, a bypass throttle device 14a, an injection bypass pipe 13a, a suction bypass pipe 15a, and a flow path switching valve 16a, and constitutes a flow path switching refrigerant circuit 20 with respect to the main refrigerant circuit. . The bypass pipe 17a is a pipe through which the refrigerant branched (bypassed) from the main refrigerant circuit flows to the internal heat exchanger 9a. The bypass throttling device 14a is an electronic expansion valve that can adjust the opening degree based on an instruction from the measurement control device 18 to reduce the pressure of the refrigerant flowing through the flow path switching refrigerant circuit 20, adjust the amount of refrigerant, and the like. The internal heat exchanger 9a performs heat exchange between the refrigerant flowing on the main refrigerant circuit side and the refrigerant passing through the bypass throttling device 14a and flowing on the flow path switching refrigerant circuit 20 side. The flow path switching valve 16a, which is a flow path switching means, switches whether the refrigerant that has passed through the internal heat exchanger 9a passes through the injection bypass pipe 13a or the suction bypass pipe 15a, and sets the flow path of the refrigerant. Do. The injection bypass pipe 13a is a pipe that has one end connected to the injection port and allows the bypassed refrigerant to flow through the injection port (perform injection bypass). The suction bypass pipe 15a is connected to the suction side (low pressure side) of the compressor, and is a pipe for flowing the bypassed refrigerant to the suction side of the compressor 3 (performing suction bypass).

一方、室内機２は、室内熱交換器６、負荷側絞り装置（膨張弁）８を有している。室内熱交換器６は冷媒と空気との熱交換を行う。例えば、暖房運転時においては凝縮器として機能し、ガス管５から流入した冷媒と空気との熱交換を行い、冷媒を凝縮させて液化（又は気液二相化）させ、液管７側に流出させる。一方、冷房運転時においては蒸発器として機能し、負荷側絞り装置８により低圧状態にされた冷媒と空気との熱交換を行い、冷媒に空気の熱を奪わせて蒸発させて気化させ、ガス管５側に流出させる。負荷側絞り装置８は、計測制御装置１８の指示に基づいて開度を調整して冷媒を減圧等することができる電子膨張弁である。   On the other hand, the indoor unit 2 includes an indoor heat exchanger 6 and a load side expansion device (expansion valve) 8. The indoor heat exchanger 6 performs heat exchange between the refrigerant and the air. For example, during heating operation, it functions as a condenser, performs heat exchange between the refrigerant flowing in from the gas pipe 5 and air, condenses the refrigerant and liquefies (or gas-liquid two-phase), and moves to the liquid pipe 7 side. Spill. On the other hand, during the cooling operation, it functions as an evaporator, performs heat exchange between the refrigerant and the air whose pressure is reduced by the load-side throttle device 8, causes the refrigerant to take heat of the air, evaporates it, and vaporizes it. It flows out to the pipe 5 side. The load-side throttle device 8 is an electronic expansion valve that can adjust the opening degree based on an instruction from the measurement control device 18 to decompress the refrigerant.

ここで、空気調和装置１００の冷媒回路に使用できる冷媒には、非共沸混合冷媒や擬似共沸混合冷媒、単一冷媒等がある。例えば、非共沸混合冷媒には、ＨＦＣ（ハイドロフルオロカーボン）冷媒であるＲ４０７Ｃ（Ｒ３２／Ｒ１２５／Ｒ１３４ａ）等がある。この非共沸混合冷媒は、沸点が異なる冷媒の混合物であるので、液相冷媒と気相冷媒との組成比率が異なるという特性を有している。擬似共沸混合冷媒には、ＨＦＣ冷媒であるＲ４１０Ａ（Ｒ３２／Ｒ１２５）やＲ４０４Ａ（Ｒ１２５／Ｒ１４３ａ／Ｒ１３４ａ）等がある。この擬似共沸混合冷媒は、非共沸混合冷媒と同様の特性の他、ＨＣＦＣ冷媒であるＲ２２の約１．６倍の動作圧力という特性を有している。   Here, the refrigerant that can be used in the refrigerant circuit of the air conditioner 100 includes a non-azeotropic mixed refrigerant, a pseudo-azeotropic mixed refrigerant, a single refrigerant, and the like. For example, the non-azeotropic refrigerant mixture includes R407C (R32 / R125 / R134a) which is an HFC (hydrofluorocarbon) refrigerant. Since this non-azeotropic refrigerant mixture is a mixture of refrigerants having different boiling points, it has a characteristic that the composition ratio of the liquid-phase refrigerant and the gas-phase refrigerant is different. The pseudo azeotropic refrigerant mixture includes R410A (R32 / R125) and R404A (R125 / R143a / R134a) which are HFC refrigerants. This pseudo azeotrope refrigerant has the same characteristics as the non-azeotrope refrigerant and has an operating pressure of about 1.6 times that of R22, which is an HCFC refrigerant.

また、単一冷媒には、ＨＣＦＣ（ハイドロクロロフルオロカーボン）冷媒であるＲ２２やＨＦＣ冷媒であるＲ１３４ａ、ＨＦＯ冷媒であるＲ１２３４ｙｆ、Ｒ１２３４ｚｅ等がある。これらの単一冷媒は、混合物ではないので、取り扱いが容易であるという特性を有している。その他、自然冷媒である二酸化炭素やプロパン、イソブタン、アンモニア等を使用することもできる。ここで、上述したＲ２２はクロロジフルオロメタン、Ｒ３２はジフルオロメタンを、Ｒ１２５はペンタフルオロエタンを、Ｒ１３４ａは１、１、１、２−テトラフルオロエタンを、Ｒ１４３ａは１、１、１−トリフルオロエタンをそれぞれ示している。このような冷媒を、空気調和装置１００の用途や目的に応じて使用するとよい。   Examples of the single refrigerant include R22 which is an HCFC (hydrochlorofluorocarbon) refrigerant, R134a which is an HFC refrigerant, R1234yf and R1234ze which are HFO refrigerants, and the like. Since these single refrigerants are not a mixture, they have a characteristic that they are easy to handle. In addition, carbon dioxide, propane, isobutane, ammonia, etc., which are natural refrigerants, can also be used. Here, R22 is chlorodifluoromethane, R32 is difluoromethane, R125 is pentafluoroethane, R134a is 1,1,1,2-tetrafluoroethane, and R143a is 1,1,1-trifluoroethane. Respectively. Such a refrigerant may be used according to the use and purpose of the air conditioner 100.

また、室外機１、室内機２には各温度センサ、圧力センサ等の検知手段が設置されている。室外機１において、温度センサ４６は圧縮機３の吐出側の配管に取り付けられて、その位置における温度（吐出温度）を検知する。同様に、温度センサ４５は室外熱交換器１２と熱源側絞り装置１１との間の配管に取り付けられて温度を検知する。また、温度センサ４９は内部熱交換器９ａと負荷側絞り装置８との間、温度センサ４７ａはバイパス絞り装置１４ａと内部熱交換器９ａとの間、温度センサ４８ａは内部熱交換器９ａと流路切替弁１６ａとの間の配管にそれぞれ取り付けられて冷媒の温度を検知する。また、温度センサ４４は室外機１の周囲の外気温度を検知する。   The outdoor unit 1 and the indoor unit 2 are provided with detection means such as temperature sensors and pressure sensors. In the outdoor unit 1, the temperature sensor 46 is attached to the discharge-side piping of the compressor 3 and detects the temperature (discharge temperature) at that position. Similarly, the temperature sensor 45 is attached to a pipe between the outdoor heat exchanger 12 and the heat source side expansion device 11 to detect the temperature. The temperature sensor 49 is connected between the internal heat exchanger 9a and the load side expansion device 8, the temperature sensor 47a is connected between the bypass expansion device 14a and the internal heat exchanger 9a, and the temperature sensor 48a is connected to the internal heat exchanger 9a. It is attached to each pipe between the path switching valve 16a and detects the temperature of the refrigerant. Further, the temperature sensor 44 detects the outside air temperature around the outdoor unit 1.

また、圧力センサ５１は圧縮機３の吐出側の配管に取り付けられて、吐出側の圧力（吐出圧力）を検知する。また、圧縮機３の吸入側の配管に取り付けられて、吸入側の圧力（吸入圧力）を検知する。   The pressure sensor 51 is attached to the discharge side piping of the compressor 3 and detects the pressure (discharge pressure) on the discharge side. Further, it is attached to a pipe on the suction side of the compressor 3 and detects the pressure (suction pressure) on the suction side.

一方、室内機２内の温度センサ４２は、室内熱交換器６とガス管５との間、温度センサ４３は室内熱交換器６と負荷側絞り装置８の間にそれぞれ取り付けられ、その位置における冷媒の温度を検知する。また、温度センサ４１は室内熱交換器６において熱交換される前の負荷側媒体（ここでは空調対象の空気）の温度を検知する。   On the other hand, the temperature sensor 42 in the indoor unit 2 is attached between the indoor heat exchanger 6 and the gas pipe 5, and the temperature sensor 43 is attached between the indoor heat exchanger 6 and the load side expansion device 8, respectively. Detect the temperature of the refrigerant. The temperature sensor 41 detects the temperature of the load-side medium (here, air to be air-conditioned) before heat exchange in the indoor heat exchanger 6.

また、室外機１内の計測制御装置１８は各温度センサ、圧力センサの検知した温度、圧力、空気調和装置の使用者から指示される運転内容等に基づいて、空気調和装置が有する機器の制御等を行う。具体的には、圧縮機３の運転、四方弁４の流路の切り替え、室外熱交換器１２に空気を送るファン（図示せず）の送風量、各絞り装置の開度等を制御する。ここでは、計測制御装置１８を室外機１内に設けているが、設置場所については特に限定するものではない。また、例えば、室内機２内に別の制御装置を備え、負荷側絞り装置８についてはその制御装置が制御するようにしてもよい。   The measurement control device 18 in the outdoor unit 1 controls the devices included in the air conditioner based on each temperature sensor, the temperature and pressure detected by the pressure sensor, the operation content instructed by the user of the air conditioner, and the like. Etc. Specifically, the operation of the compressor 3, the switching of the flow path of the four-way valve 4, the blowing amount of a fan (not shown) that sends air to the outdoor heat exchanger 12, the opening degree of each expansion device, and the like are controlled. Here, the measurement control device 18 is provided in the outdoor unit 1, but the installation location is not particularly limited. Further, for example, another control device may be provided in the indoor unit 2, and the control device may control the load-side throttle device 8.

図２は暖房運転において圧縮機３の吸入圧力が低い状態でインジェクションポートへの冷媒のバイパスを行っている状態を示すｐ−ｈ線図である。次に、この空気調和装置１００の運転動作について冷媒の流れに基づいて説明する。まず、比較的外気温度が低い場合の暖房運転時の動作について図１及び図２により説明する。   FIG. 2 is a ph diagram showing a state where the refrigerant is bypassed to the injection port in the heating operation with the suction pressure of the compressor 3 being low. Next, the operation of the air conditioner 100 will be described based on the refrigerant flow. First, the operation at the time of heating operation when the outside air temperature is relatively low will be described with reference to FIGS.

暖房運転時に、計測制御装置１８は、四方弁４における冷媒の流路が図１の破線方向となるように設定する。圧縮機３は吸入した冷媒を吐出する。圧縮機３から吐出された高温高圧のガス冷媒（図２の点（ａ））は四方弁４を経て室外機１を流出し、ガス管５を経て室内機２に流入する。そして、室内機２において、凝縮器となる室内熱交換器６に流入し、放熱しながら凝縮液化して高圧の液冷媒となる（図２の点（ｂ））。冷媒が放熱した熱は、負荷側の空気や水などの負荷側媒体に与えることで暖房を行う。   During the heating operation, the measurement control device 18 sets the refrigerant flow path in the four-way valve 4 in the direction of the broken line in FIG. The compressor 3 discharges the sucked refrigerant. The high-temperature and high-pressure gas refrigerant discharged from the compressor 3 (point (a) in FIG. 2) flows out of the outdoor unit 1 through the four-way valve 4 and flows into the indoor unit 2 through the gas pipe 5. And in the indoor unit 2, it flows in into the indoor heat exchanger 6 used as a condenser, is condensed and liquefied while dissipating heat, and becomes a high-pressure liquid refrigerant (point (b) in FIG. 2). Heat is released by the heat released from the refrigerant to a load-side medium such as air or water on the load side.

室内熱交換器６から流出した高圧の冷媒は、負荷側絞り装置８で若干減圧された後（図２の点（ｃ））、液管７を経由して、室外機１に流入する。室外機１に流入した冷媒は分岐して、一部の冷媒は、主冷媒回路を内部熱交換器９ａ側に流れ、残りの冷媒はバイパス配管１７ａ側に流れる。内部熱交換器９ａ側に流れた冷媒は、バイパス配管１７ａ側に流れてバイパス絞り装置１４ａを通過した中温の冷媒と熱交換し、冷却される（図２の点（ｄ））。さらに、熱源側絞り装置１１で低圧まで減圧されて二相冷媒となる（図２の点（ｅ））。そして、蒸発器となる室外熱交換器１２に流入し、そこで吸熱し、蒸発ガス化される（図２の点（ｆ））。その後、四方弁４を経て、圧縮機３に吸入される。   The high-pressure refrigerant that has flowed out of the indoor heat exchanger 6 is slightly decompressed by the load side expansion device 8 (point (c) in FIG. 2), and then flows into the outdoor unit 1 via the liquid pipe 7. The refrigerant flowing into the outdoor unit 1 branches, a part of the refrigerant flows through the main refrigerant circuit to the internal heat exchanger 9a side, and the remaining refrigerant flows to the bypass pipe 17a side. The refrigerant that has flowed to the internal heat exchanger 9a side is cooled by exchanging heat with the medium-temperature refrigerant that has flowed to the bypass pipe 17a side and passed through the bypass expansion device 14a (point (d) in FIG. 2). Further, the pressure is reduced to a low pressure by the heat source side expansion device 11 to become a two-phase refrigerant (point (e) in FIG. 2). And it flows in the outdoor heat exchanger 12 used as an evaporator, absorbs heat there, and is evaporated and gasified (point (f) of FIG. 2). Thereafter, the air is sucked into the compressor 3 through the four-way valve 4.

一方、バイパス配管１７ａ側に分岐してバイパスされた冷媒は、バイパス絞り装置１４で、中間圧まで減圧され、中温の二相冷媒となる（図２の点（ｇ））。そして、前述したように内部熱交換器９ａで主冷媒回路側を通過する冷媒と熱交換することで加熱される（図２の点（ｈ））。流路切替弁１６ａ、インジェクションバイパス配管１３ａを経由し、インジェクションポートを介して圧縮機３にインジェクションされる。圧縮機３内部では、主冷媒回路において吸入された冷媒（図２の点（ｆ））が中間圧まで圧縮、加熱される（図２の点（ｉ））。その後、インジェクションポートから流入した冷媒と合流し、温度が低下した後で（図２の点（ｊ））、高圧まで圧縮されて吐出される（図２の点（ａ））。   On the other hand, the refrigerant branched and bypassed to the bypass pipe 17a side is depressurized to an intermediate pressure by the bypass expansion device 14, and becomes a medium-temperature two-phase refrigerant (point (g) in FIG. 2). And as above-mentioned, it heats by exchanging heat with the refrigerant | coolant which passes the main refrigerant circuit side by the internal heat exchanger 9a (point (h) of FIG. 2). It is injected into the compressor 3 through the injection port via the flow path switching valve 16a and the injection bypass pipe 13a. Inside the compressor 3, the refrigerant sucked in the main refrigerant circuit (point (f) in FIG. 2) is compressed and heated to an intermediate pressure (point (i) in FIG. 2). Thereafter, the refrigerant merges with the refrigerant flowing in from the injection port, and after the temperature is lowered (point (j) in FIG. 2), it is compressed to a high pressure and discharged (point (a) in FIG. 2).

ここで、空気調和装置１００の冷媒回路の構成は、いわゆるガスインジェクション回路となっている。これは、例えば、凝縮器となる室内熱交換器６を出て中間圧まで減圧された冷媒のうち、ガス冷媒を圧縮機３にインジェクションするものである。一般には、気液分離器で中間圧の冷媒を液冷媒とガス冷媒とに分離してガス冷媒をインジェクションする構成が多い。本実施の形態の空気調和装置１００では、図２に示されるように、内部熱交換器９ａで熱交換することにより、熱的に液冷媒とガス冷媒とを分離し、ガス冷媒をインジェクションする構成としている。   Here, the configuration of the refrigerant circuit of the air conditioner 100 is a so-called gas injection circuit. This is, for example, for injecting a gas refrigerant into the compressor 3 out of the refrigerant that has exited the indoor heat exchanger 6 serving as a condenser and has been reduced to an intermediate pressure. Generally, there are many configurations in which a gas refrigerant is injected by separating an intermediate pressure refrigerant into a liquid refrigerant and a gas refrigerant in a gas-liquid separator. In the air conditioning apparatus 100 of the present embodiment, as shown in FIG. 2, the liquid refrigerant and the gas refrigerant are thermally separated by heat exchange with the internal heat exchanger 9 a and the gas refrigerant is injected. It is said.

ガスインジェクション回路としてすることにより以下のような効果が得られる。まず、ガスインジェクションを行うことにより、圧縮機３から吐出される冷媒の流量が増加する。例えば、圧縮機３から吐出される冷媒流量Ｇｄｉｓは、圧縮機３で吸入される冷媒流量Ｇｓｕｃとインジェクションされる冷媒流量Ｇｉｎｊとの和となる。従って、凝縮器となる熱交換器に流れる冷媒流量が増加するので、特に暖房運転の場合には、暖房能力を増加させることができる。   By using a gas injection circuit, the following effects can be obtained. First, by performing gas injection, the flow rate of the refrigerant discharged from the compressor 3 increases. For example, the refrigerant flow rate Gdis discharged from the compressor 3 is the sum of the refrigerant flow rate Gsuc sucked by the compressor 3 and the injected refrigerant flow rate Ginj. Therefore, since the flow rate of the refrigerant flowing through the heat exchanger serving as a condenser increases, the heating capacity can be increased particularly in the heating operation.

一方、図２に示されるように、内部熱交換器９ａでの熱交換により、蒸発器となる熱交換器に流入する冷媒エンタルピが低下し、蒸発器での冷媒エンタルピ差が増大する。従って、暖房運転時には、蒸発器となる室外熱交換器１２においては、外気からの吸熱による熱交換量が増加するため暖房能力が増加する。また、ガスインジェクションを行う場合は効率改善効果も得られる。蒸発器に流入する冷媒は、一般に気液二相冷媒であるが、このうち、ガス冷媒は蒸発器における熱交換に寄与しない。圧縮機３から見ると、この低圧のガス冷媒も、蒸発器で蒸発したガス冷媒と一緒に高圧に昇圧する仕事を行っていることになる。   On the other hand, as shown in FIG. 2, due to heat exchange in the internal heat exchanger 9a, the refrigerant enthalpy flowing into the heat exchanger serving as the evaporator is reduced, and the refrigerant enthalpy difference in the evaporator is increased. Therefore, during the heating operation, in the outdoor heat exchanger 12 serving as an evaporator, the amount of heat exchange due to heat absorption from the outside air increases, so that the heating capacity increases. In addition, when gas injection is performed, an efficiency improvement effect can be obtained. The refrigerant flowing into the evaporator is generally a gas-liquid two-phase refrigerant. Among these, the gas refrigerant does not contribute to heat exchange in the evaporator. From the viewpoint of the compressor 3, this low-pressure gas refrigerant also performs the work of increasing the pressure to a high pressure together with the gas refrigerant evaporated in the evaporator.

ガスインジェクションを行うことで、蒸発器に流入するガス冷媒のうちの一部を中間圧で抜き出してインジェクションすることになる。このため、圧縮機３は、インジェクションに係る冷媒は中間圧から高圧に昇圧し、圧縮することになる。したがって、インジェクションされる流量のガス冷媒については、低圧から中間圧まで昇圧する圧縮仕事が不要になり、この分、効率改善がなされる。   By performing the gas injection, a part of the gas refrigerant flowing into the evaporator is extracted at an intermediate pressure and injected. For this reason, the compressor 3 boosts the refrigerant related to the injection from the intermediate pressure to the high pressure and compresses the refrigerant. Therefore, the work of compression for increasing the flow rate of the gas refrigerant from the low pressure to the intermediate pressure becomes unnecessary, and the efficiency is improved correspondingly.

また、一部がバイパス配管１７ａ側に流れることで、蒸発器に流れる冷媒量が減少するため、蒸発器を通過する際の圧力損失が低減する。これにより圧縮機３の吸入側に吸入圧力が増加するため効率が改善される。この効率の改善率は、圧力損失が大きいほど効果が大きい。したがって、蒸発器から圧縮機吸入に至る配管が長い場合や、圧縮機３の運転容量が大きく、循環する冷媒量が多いほど効果が大きくなる。   Moreover, since the refrigerant | coolant amount which flows into an evaporator reduces because a part flows into the bypass piping 17a side, the pressure loss at the time of passing an evaporator reduces. As a result, the suction pressure increases on the suction side of the compressor 3, thereby improving the efficiency. The efficiency improvement rate is more effective as the pressure loss is larger. Therefore, the effect increases when the piping from the evaporator to the compressor suction is long, or when the operating capacity of the compressor 3 is large and the amount of circulating refrigerant is large.

図３は暖房運転において圧縮機３の吸入圧力が高い状態でインジェクションポートへの冷媒のバイパスを行っている状態を示すｐ−ｈ線図である。次に、比較的外気温度が高い場合の暖房運転時の運転動作について図１及び図３により説明する。冷媒の流れ等による冷凍サイクルの形状等については、図２の場合と同様であるが、外気温度が高いため、圧縮機３の吸入側における吸入圧力が増加する。インジェクションポートにおける圧力（インジェクション圧力）Ｐm ［ＭＰａ］は、圧縮機３の圧縮室内におけるインジェクションポートの位置にもよるが、一般的に、圧縮機３の吐出側の吐出圧力Ｐd ［ＭＰａ］及び圧縮機３の吸入側の吸入圧力Ｐs ［ＭＰａ］から次式（１）で推測することが知られている。 FIG. 3 is a ph diagram showing a state in which the refrigerant is bypassed to the injection port in a state where the suction pressure of the compressor 3 is high in the heating operation. Next, the operation during heating operation when the outside air temperature is relatively high will be described with reference to FIGS. The shape and the like of the refrigeration cycle due to the refrigerant flow and the like are the same as in the case of FIG. 2, but the intake pressure on the intake side of the compressor 3 increases because the outside air temperature is high. Although the pressure (injection pressure) P m [MPa] at the injection port depends on the position of the injection port in the compression chamber of the compressor 3, generally, the discharge pressure P d [MPa] on the discharge side of the compressor 3 and It is known that the following equation (1) is used to estimate from the suction pressure P s [MPa] on the suction side of the compressor 3.

Ｐm ＝（Ｐd ×Ｐs ）1/2 …（１） P m = (P d × P s ) 1/2 (1)

式（１）から分かるように吸入圧力Ｐs が増加するとインジェクション圧力Ｐm も増加する。そして、インジェクション圧力Ｐm が増加することで、インジェクションポートに吸入される中温の冷媒温度も高くなるため、内部熱交換器９ａでの冷却量が減少する。 As can be seen from equation (1), when the suction pressure P s increases, the injection pressure P m also increases. Then, by injection pressure P m is increased, since the higher temperature of the refrigerant medium temperature sucked into the injection port, the cooling amount in the internal heat exchanger 9a is reduced.

内部熱交換器９ａでの冷却量が減少すると、内部熱交換器９ａでの熱交換による蒸発器での冷凍効果（図３の点（ｆ）と図３の点（ｇ）のエンタルピ差）の増大効果が減少するため、暖房能力の増大効果が減少する。したがって、ＣＯＰの向上率はインジェクション圧力Ｐm が大きいほど減少することになる。 When the cooling amount in the internal heat exchanger 9a decreases, the refrigeration effect in the evaporator due to heat exchange in the internal heat exchanger 9a (difference in enthalpy between point (f) in FIG. 3 and point (g) in FIG. 3) Since the increase effect decreases, the increase effect of the heating capacity decreases. Therefore, the improvement rate of COP decreases as the injection pressure P m increases.

図４は暖房運転において圧縮機３の吸入圧力が高い状態で吸入側に冷媒のバイパスを行っている場合を示すｐ−ｈ線図である。前述したように、暖房運転においては、室外機１に流入した冷媒は分岐して、一部の冷媒は内部熱交換器９ａ側に流れ、残りの冷媒はバイパス配管１７ａ側に流れる。内部熱交換器９ａ側に流れた冷媒は、バイパス配管１７ａ側に流れてバイパス絞り装置１４ａを通過した低温の冷媒と熱交換し、冷却される（図４の点（ｄ））。さらに、熱源側絞り装置１１で低圧まで減圧されて二相冷媒となる（図４の点（ｅ））。そして、蒸発器となる室外熱交換器１２に流入し、そこで吸熱し、蒸発ガス化される（図４の点（ｆ））。その後、四方弁４を経て、圧縮機３に吸入される。   FIG. 4 is a ph diagram illustrating a case where the refrigerant is bypassed to the suction side in the heating operation with the suction pressure of the compressor 3 being high. As described above, in the heating operation, the refrigerant flowing into the outdoor unit 1 branches, a part of the refrigerant flows to the internal heat exchanger 9a side, and the remaining refrigerant flows to the bypass pipe 17a side. The refrigerant that has flowed to the internal heat exchanger 9a side exchanges heat with the low-temperature refrigerant that has flowed to the bypass pipe 17a side and passed through the bypass expansion device 14a, and is cooled (point (d) in FIG. 4). Further, the pressure is reduced to a low pressure by the heat source side expansion device 11 to become a two-phase refrigerant (point (e) in FIG. 4). And it flows in the outdoor heat exchanger 12 used as an evaporator, absorbs heat there, and is evaporated and gasified (point (f) of FIG. 4). Thereafter, the air is sucked into the compressor 3 through the four-way valve 4.

一方、バイパス配管１７ａ側にバイパスされた冷媒は、バイパス絞り装置１４で、低圧まで減圧され、低温の二相冷媒となる（図４の点（ｇ））。そして、前述したように内部熱交換器９ａで高圧冷媒と熱交換して加熱され（図４の点（ｈ））、流路切替弁１６ａ、吸入バイパス配管１５ａを介して、室外熱交換器１２を通過した冷媒と合流して圧縮機３に吸入される。   On the other hand, the refrigerant bypassed to the bypass piping 17a side is depressurized to a low pressure by the bypass expansion device 14, and becomes a low-temperature two-phase refrigerant (point (g) in FIG. 4). As described above, heat is exchanged with the high-pressure refrigerant in the internal heat exchanger 9a and heated (point (h) in FIG. 4), and the outdoor heat exchanger 12 is passed through the flow path switching valve 16a and the suction bypass pipe 15a. The refrigerant that has passed through the refrigerant flows and is sucked into the compressor 3.

圧縮機３の吸入側にバイパスする冷媒と内部熱交換器９ａで熱交換を行った場合は、圧縮機３のインジェクション圧力の飽和温度よりも低い低温冷媒との熱交換となる。このため、蒸発器での冷凍効果（図４の点（ｆ）と図４の点（ｇ）とのエンタルピ差）の増大効果がインジェクションバイパスに比較し大きく、暖房能力の増大効果が増加する。   When heat is exchanged between the refrigerant bypassed to the suction side of the compressor 3 and the internal heat exchanger 9a, heat exchange is performed with a low-temperature refrigerant lower than the saturation temperature of the injection pressure of the compressor 3. For this reason, the effect of increasing the refrigeration effect in the evaporator (the enthalpy difference between the point (f) in FIG. 4 and the point (g) in FIG. 4) is larger than that of the injection bypass, and the effect of increasing the heating capacity is increased.

また、圧縮機３のインジェクション圧力Ｐm が高いほど（吸入圧力Ｐs が高いほど）、冷媒密度が高くなるため、圧縮機３の運転容量が同一の場合、冷媒循環量が増加する。このため、吸入バイパス回路適用時の圧力損失低減によるＣＯＰ向上率が増加する。ここで、インジェクションバイパスと比較して、吸入バイパスともに、バイパスによる蒸発器から圧縮機３の吸入側に至る圧力損失の低減効果があるが、吸入バイパスの方が冷凍効果の増大効果が大きいため、圧力損失低減によるＣＯＰ向上率が大きい。 Further, the higher the injection pressure P m of the compressor 3 (the higher the suction pressure P s ), the higher the refrigerant density. Therefore, when the operating capacity of the compressor 3 is the same, the refrigerant circulation amount increases. For this reason, the COP improvement rate by the pressure loss reduction at the time of suction bypass circuit application increases. Here, compared with the injection bypass, both the suction bypass has an effect of reducing the pressure loss from the evaporator to the suction side of the compressor 3 by the bypass, but the suction bypass has a larger effect of increasing the refrigeration effect. The COP improvement rate due to pressure loss reduction is large.

図５は流路切替弁１６ａを切り替えることで実現可能なインジェクションバイパス回路及び吸入バイパス回路のそれぞれのインジェクション圧力Ｐm に対するＣＯＰ向上率の関係を表す図である。図５は、圧縮機３における圧縮機運転容量とインジェクション圧力によって、流路切替弁１６ａにおける冷媒の流路をインジェクションバイパス配管１３ａ側にするか、吸入バイパス配管１５ａ側にするかを選択する最適なポイントが存在することを示している。 Figure 5 is a graph depicting the relationship of the COP improvement ratio relative to each of the injection pressure P m of the injection bypass circuit and the suction bypass circuit can be realized by switching the flow path switching valve 16a. FIG. 5 shows an optimum selection of whether the refrigerant flow path in the flow path switching valve 16a is on the injection bypass pipe 13a side or on the suction bypass pipe 15a side, depending on the compressor operating capacity and the injection pressure in the compressor 3. Indicates that a point exists.

例えば、圧縮機運転容量が小さい場合、インジェクション圧力が図５に示す点Ａ以下であれば流路切替弁１６ａにおける冷媒の流路を図１の実線側として、インジェクションバイパス配管１３ａに冷媒を流すインジェクションバイパス回路とする。一方、点Ａ以上であれば図１の破線側として吸入バイパス配管１５ａに流す吸入バイパス回路とすることでＣＯＰの高い運転を実現できる。同様に、圧縮機運転容量が大きい場合は、（図５の点Ｂ）の状態をもって流路切替弁１６ａを切り替えることでＣＯＰの高い運転を実現することができる。   For example, when the compressor operating capacity is small, if the injection pressure is equal to or lower than point A shown in FIG. 5, the refrigerant flow in the flow path switching valve 16a is set to the solid line side in FIG. 1, and the refrigerant flows through the injection bypass pipe 13a. Use a bypass circuit. On the other hand, if the point A is equal to or higher than the point A, an operation with a high COP can be realized by using a suction bypass circuit that flows to the suction bypass pipe 15a on the broken line side in FIG. Similarly, when the compressor operating capacity is large, operation with a high COP can be realized by switching the flow path switching valve 16a in the state of (point B in FIG. 5).

流路切替弁１６ａの流路を切り替える判定条件を、例えば、圧縮機３の運転容量とインジェクション圧力の関数のデータとしてあらかじめ計測制御装置１８の記憶手段等（図示せず）に保持しておく等によって、計測制御装置１８は制御可能とする。   Determination conditions for switching the flow path of the flow path switching valve 16a are stored in advance in a storage unit (not shown) of the measurement control device 18 as data of a function of the operating capacity of the compressor 3 and the injection pressure, for example. Thus, the measurement control device 18 can be controlled.

インジェクション圧力Ｐm は、圧縮機吐出の吐出圧力Ｐd ［ＭＰａ］及び圧縮機吸入の吸入圧力Ｐs ［ＭＰａ］から前述の推測式から求めてもよい。また、インジェクションバイパス回路としている場合は、温度センサ４７ａの検知に係る温度がインジェクション圧力Ｐm の飽和温度となるため、温度センサ４７ａの検知に係る温度に基づいて圧力に換算して求めてもよい。 The injection pressure P m may be obtained from the above-described estimation formula from the discharge pressure P d [MPa] of the compressor discharge and the suction pressure P s [MPa] of the compressor suction. Also, if you are injection bypass circuit, since the temperature of the detection of the temperature sensor 47a is the saturation temperature of the injection pressure P m, may be obtained in terms of pressure based on the temperature according to the detection of the temperature sensor 47a .

図６は冷房運転時のｐ−ｈ線図である。次に、冷房運転時の空気調和装置１００の運転動作について図１及び図６により説明する。暖房運転時に、計測制御装置１８は、四方弁４における冷媒の流路が図１の実線方向となるように設定する。基本的にｐ−ｈ線図上の冷凍サイクルが辿る方向等については暖房運転の場合と同様である。圧縮機３は吸入した冷媒を高温高圧のガス冷媒として吐出する（図６の点（ａ））。冷媒は四方弁４を経て、凝縮器となる室外熱交換器１２で放熱しながら凝縮液化し高圧の液冷媒となる（図６の点（ｂ））。室外熱交換器１２を出た高圧の冷媒は、熱源側絞り装置１１で若干減圧された後（図６の点（ｃ））、内部熱交換器９ａで、バイパス配管１７ａに一部冷媒をバイパスした後で、バイパス絞り装置１４ａで減圧され、流路切替弁１６ａ、インジェクションバイパス配管１３ａを経由し、インジェクションポートに吸入される中温となった冷媒と熱交換し、冷却される（図６の点（ｄ））。そして、その後、液管７を経由し、室内機２に流入する。冷媒は負荷側絞り装置８で低圧まで減圧され二相冷媒となり（図６の点（ｅ））、その後、蒸発器となる室内熱交換器６に流入し、そこで吸熱し、蒸発ガス化される（図６の点（ｆ））。負荷側の空気や水などの負荷側媒体の熱を冷媒に吸熱することで冷房を行う。その後、ガス管５を経由し、室外機１に流入し、四方弁４を経て、圧縮機３に吸入される。   FIG. 6 is a ph diagram during cooling operation. Next, the operation of the air conditioner 100 during the cooling operation will be described with reference to FIGS. 1 and 6. During the heating operation, the measurement control device 18 sets the refrigerant flow path in the four-way valve 4 to be in the direction of the solid line in FIG. The direction that the refrigeration cycle follows on the ph diagram is basically the same as in the heating operation. The compressor 3 discharges the sucked refrigerant as a high-temperature and high-pressure gas refrigerant (point (a) in FIG. 6). The refrigerant passes through the four-way valve 4, condenses and liquefies while dissipating heat in the outdoor heat exchanger 12 serving as a condenser, and becomes a high-pressure liquid refrigerant (point (b) in FIG. 6). The high-pressure refrigerant that exits the outdoor heat exchanger 12 is slightly decompressed by the heat source side expansion device 11 (point (c) in FIG. 6), and then partially bypasses the bypass piping 17a by the internal heat exchanger 9a. After that, the pressure is reduced by the bypass expansion device 14a, and the refrigerant is cooled by exchanging heat with the medium-temperature refrigerant sucked into the injection port via the flow path switching valve 16a and the injection bypass pipe 13a (point of FIG. 6). (D)). Then, it flows into the indoor unit 2 via the liquid pipe 7. The refrigerant is depressurized to a low pressure by the load side expansion device 8 to become a two-phase refrigerant (point (e) in FIG. 6), and then flows into the indoor heat exchanger 6 serving as an evaporator, where it absorbs heat and is vaporized into gas. (Point (f) in FIG. 6). Cooling is performed by absorbing heat of the load side medium such as air or water on the load side into the refrigerant. Thereafter, the gas flows into the outdoor unit 1 through the gas pipe 5 and is sucked into the compressor 3 through the four-way valve 4.

一方、インジェクションバイパス配管１３ａにバイパスされた冷媒は、バイパス絞り装置１４で、中間圧まで減圧され、中温の二相冷媒となり（図６の点（ｇ））、その後は内部熱交換器９ａで高圧冷媒と熱交換し加熱され（図６の点（ｈ））、圧縮機３にインジェクションされる。圧縮機３内部では、吸入された冷媒（図６の点（ｆ））が中間圧まで圧縮、加熱された（図６の点（ｉ））後で、インジェクションされる冷媒と合流し、温度低下した後で（図６の点（ｊ））、高圧まで圧縮され吐出される（図６の点（ａ））。   On the other hand, the refrigerant bypassed to the injection bypass pipe 13a is depressurized to an intermediate pressure by the bypass expansion device 14 to become a medium-temperature two-phase refrigerant (point (g) in FIG. 6), and thereafter, the internal heat exchanger 9a increases the pressure. Heat is exchanged with the refrigerant and heated (point (h) in FIG. 6), and is injected into the compressor 3. Inside the compressor 3, after the sucked refrigerant (point (f) in FIG. 6) is compressed and heated to an intermediate pressure (point (i) in FIG. 6), it merges with the injected refrigerant and the temperature drops. After that (point (j) in FIG. 6), it is compressed and discharged to a high pressure (point (a) in FIG. 6).

冷房運転時のｐ−ｈ線図は暖房運転時とほぼ同一になり、どちらの運転モードでも同様の運転を実現できる。そして流路切替弁１６ａを切り替えることで、運転状態に応じて高効率な運転を実現することができる。   The ph diagram during cooling operation is almost the same as during heating operation, and the same operation can be realized in either operation mode. And by switching the flow path switching valve 16a, highly efficient driving | operation is realizable according to a driving | running state.

図７は暖房運転時に計測制御装置１８が行う制御動作を説明する図である。暖房運転時には、まず、圧縮機３の容量、熱源側絞り装置１１の開度、バイパス絞り装置１４ａの開度、負荷側絞り装置８の開度が初期値に設定される（ステップＳ１）。そして、所定時間が経過したものと判断すると（ステップＳ２）、運転状態に応じて各アクチュエータを制御するため、以下の処理を行う。   FIG. 7 is a diagram illustrating a control operation performed by the measurement control device 18 during the heating operation. During the heating operation, first, the capacity of the compressor 3, the opening of the heat source side expansion device 11, the opening of the bypass expansion device 14a, and the opening of the load side expansion device 8 are set to initial values (step S1). When it is determined that the predetermined time has elapsed (step S2), the following processing is performed to control each actuator in accordance with the operating state.

インジェクション圧力Ｐm を、例えば前述した（１）式に基づいて圧縮機吐出圧力Ｐd 、圧縮機吸入圧力Ｐs から演算等により推測する（ステップＳ３）。そして、インジェクション圧力Ｐm 、圧縮機３の運転容量から得られるＣＯＰの大きさに基づいて、インジェクションバイパスを行うか吸入バイパスを行うかを決定し、流路切替弁１６ａによる流路設定を行う（ステップＳ４）。 The injection pressure P m is estimated by calculation or the like from the compressor discharge pressure P d and the compressor suction pressure P s based on the above-described equation (1), for example (step S3). Then, based on the injection pressure P m and the COP obtained from the operating capacity of the compressor 3, it is determined whether injection bypass or suction bypass is to be performed, and the flow path setting by the flow path switching valve 16a is performed ( Step S4).

また、圧縮機３の容量について、基本的に室内機２の温度センサ４１の計測に係る空気温度が、空気調和装置を使用する者が設定する温度になるような制御を行う。このため、温度センサ４１の計測に係る空気温度と使用者による設定値とを比較する（ステップＳ５）。そして、空気温度が設定値を含む所定範囲内であると判断すると、圧縮機３の容量をそのまま維持するようにし、次のステップＳ７に進む。また、空気温度が所定範囲の下限より低いと判断すると、圧縮機３の容量を増加し、空気温度が所定範囲の上限より高いと判断すると、圧縮機３の容量を減少する圧縮機容量変更制御を行い（ステップＳ６）、次のステップＳ７に進む。   Further, the capacity of the compressor 3 is basically controlled so that the air temperature related to the measurement by the temperature sensor 41 of the indoor unit 2 becomes a temperature set by a person using the air conditioner. For this reason, the air temperature which concerns on the measurement of the temperature sensor 41, and the setting value by a user are compared (step S5). When it is determined that the air temperature is within a predetermined range including the set value, the capacity of the compressor 3 is maintained as it is, and the process proceeds to the next step S7. Further, when it is determined that the air temperature is lower than the lower limit of the predetermined range, the capacity of the compressor 3 is increased, and when it is determined that the air temperature is higher than the upper limit of the predetermined range, the compressor capacity change control for decreasing the capacity of the compressor 3. (Step S6), the process proceeds to the next step S7.

各絞り装置の開度制御は以下のように行う。まず、負荷側絞り装置８の開度については、圧力センサ５２の検知に係る高圧冷媒の圧力から飽和温度に換算する。そして、飽和温度と温度センサ４３の検知に係る室内熱交換器６の冷媒流出口の温度との温度差となる室内熱交換器６の冷媒流出口における冷媒過冷却度ＳＣが予め設定された所定温度となる目標値（例えば１０℃）になるように開度を制御する。このため、室内熱交換器６の冷媒流出口の冷媒過冷却度ＳＣと目標値とを比較する（ステップＳ７）。そして、室内熱交換器６の冷媒流出口における冷媒過冷却度ＳＣが目標値を含む所定範囲内であると判断すると、負荷側絞り装置８の開度をそのまま維持するようにし、次のステップＳ９に進む。また、室内熱交換器６の冷媒流出口における冷媒過冷却度ＳＣが所定範囲の上限より大きいと判断すると、負荷側絞り装置８の開度を大きくし、冷媒過冷却度ＳＣが所定範囲の下限より小さいと判断すると、負荷側絞り装置８の開度を小さくする負荷側絞り装置開度変更制御を行い（ステップＳ８）、次のステップＳ９に進む。   The opening control of each expansion device is performed as follows. First, the opening degree of the load side expansion device 8 is converted from the pressure of the high-pressure refrigerant related to the detection by the pressure sensor 52 to the saturation temperature. And the refrigerant | coolant subcooling degree SC in the refrigerant | coolant outflow port of the indoor heat exchanger 6 used as the temperature difference with saturation temperature and the temperature of the refrigerant | coolant outflow port of the indoor heat exchanger 6 which the detection of the temperature sensor 43 detects is predetermined. The opening degree is controlled so as to be a target value (for example, 10 ° C.) that is a temperature. For this reason, the refrigerant subcooling degree SC at the refrigerant outlet of the indoor heat exchanger 6 is compared with the target value (step S7). If it is determined that the refrigerant supercooling degree SC at the refrigerant outlet of the indoor heat exchanger 6 is within a predetermined range including the target value, the opening degree of the load side expansion device 8 is maintained as it is, and the next step S9. Proceed to If it is determined that the refrigerant supercooling degree SC at the refrigerant outlet of the indoor heat exchanger 6 is larger than the upper limit of the predetermined range, the opening degree of the load side expansion device 8 is increased and the refrigerant subcooling degree SC is lower than the lower limit of the predetermined range. If it is determined that it is smaller, load side throttle device opening degree change control is performed to reduce the opening degree of the load side throttle device 8 (step S8), and the process proceeds to the next step S9.

次に、バイパス絞り装置１４ａの開度については、高効率運転をはかることと冷凍機油の劣化防止をはかることとに基づいて制御を行う。温度センサ４８ａの検知に係る内部熱交換器９ａの冷媒流出口の温度と温度センサ４７ａの検知に係る内部熱交換器９ａに流入するバイパス絞り装置１４ａを通過した低圧側の冷媒の飽和温度との温度差となる内部熱交換器９ａの冷媒流出口の冷媒過熱度ＳＨが、予め設定された所定温度となる目標値（例えば１℃）になるように開度を制御する。このため、内部熱交換器９ａの冷媒流出口の冷媒過熱度ＳＨと目標値とを比較する（ステップＳ９）。そして、内部熱交換器９ａの冷媒流出口の冷媒過熱度ＳＨが目標値を含む所定範囲内であると判断すると、次のステップＳ１１に進む。また、内部熱交換器９ａの冷媒流出口の冷媒過熱度ＳＨが所定範囲の上限より大きいと判断すると、バイパス絞り装置１４ａの開度を大きくし、冷媒過熱度ＳＨが所定範囲の下限より小さいと判断すると、バイパス絞り装置１４ａの開度を小さくするバイパス絞り装置開度変更制御を行い（ステップＳ１０）、次のステップＳ１２に進む。このようにして冷媒のバイパス量を制御することで、内部熱交換器９ａの熱交換性能を高くすることができるとともに、冷媒エンタルピ差も適度に確保できるような運転をすることができる。このため、高効率の運転を行うことができる。ここで、このような運転を行うために内部熱交換器９ａの冷媒流出口の冷媒過熱度ＳＨの目標値はなるべく小さく設定する方がよい。   Next, the opening degree of the bypass expansion device 14a is controlled based on the high efficiency operation and the prevention of deterioration of the refrigerating machine oil. The temperature of the refrigerant outlet of the internal heat exchanger 9a related to the detection of the temperature sensor 48a and the saturation temperature of the low-pressure side refrigerant that has passed through the bypass expansion device 14a flowing into the internal heat exchanger 9a related to the detection of the temperature sensor 47a. The degree of opening is controlled so that the refrigerant superheat degree SH at the refrigerant outlet of the internal heat exchanger 9a, which is a temperature difference, becomes a target value (for example, 1 ° C.) that is a predetermined temperature set in advance. For this reason, the refrigerant superheat degree SH at the refrigerant outlet of the internal heat exchanger 9a is compared with the target value (step S9). If it is determined that the refrigerant superheat degree SH at the refrigerant outlet of the internal heat exchanger 9a is within a predetermined range including the target value, the process proceeds to the next step S11. If it is determined that the refrigerant superheat degree SH at the refrigerant outlet of the internal heat exchanger 9a is larger than the upper limit of the predetermined range, the opening degree of the bypass expansion device 14a is increased, and the refrigerant superheat degree SH is smaller than the lower limit of the predetermined range. If it judges, bypass throttling device opening degree change control which makes the opening degree of the bypass throttling device 14a small will be performed (step S10), and it will progress to the following step S12. By controlling the bypass amount of the refrigerant in this way, it is possible to increase the heat exchange performance of the internal heat exchanger 9a and to perform an operation that can appropriately ensure the refrigerant enthalpy difference. For this reason, a highly efficient driving | operation can be performed. Here, in order to perform such an operation, it is better to set the target value of the refrigerant superheat degree SH at the refrigerant outlet of the internal heat exchanger 9a as small as possible.

さらに、バイパス絞り装置１４ａは、圧縮機３の吐出温度上昇による冷凍機油の劣化防止のための開度制御を行う。温度センサ４６の検知に係る圧縮機３の吐出温度が、予め設定された所定温度となる設定値（例えば１００℃）以下になるように制御される。このため、温度センサ４６の検知に係る圧縮機３の吐出温度と設定値とを比較する（ステップＳ１１）。そして、圧縮機３の吐出温度が設定値以下であると判断すると、バイパス絞り装置１４ａの開度をそのまま維持するようにし、次のステップＳ１２に進む。また、圧縮機３の吐出温度が設定値より高いと判断すると、バイパス絞り装置１４ａの開度を大きくするバイパス絞り装置開度変更制御を行い（ステップＳ１０）、次のステップＳ１２に進む。   Further, the bypass expansion device 14 a performs opening degree control for preventing deterioration of the refrigerating machine oil due to an increase in the discharge temperature of the compressor 3. The discharge temperature of the compressor 3 related to the detection of the temperature sensor 46 is controlled to be equal to or lower than a set value (for example, 100 ° C.) that is a predetermined temperature set in advance. For this reason, the discharge temperature of the compressor 3 according to the detection of the temperature sensor 46 is compared with the set value (step S11). And if it judges that the discharge temperature of the compressor 3 is below a preset value, it will maintain the opening degree of the bypass expansion apparatus 14a as it is, and will progress to following step S12. If it is determined that the discharge temperature of the compressor 3 is higher than the set value, bypass throttling device opening degree change control for increasing the opening degree of the bypass throttling device 14a is performed (step S10), and the process proceeds to the next step S12.

次に、熱源側絞り装置１１の開度については、温度センサ４９の検知に係る温度から熱源側絞り装置１１に流入する冷媒の飽和圧力に換算する。そして、飽和圧力が予め設定された所定圧力となる目標値（例えば２ＭＰａ）になるように制御する。ここで、目標値は、バイパス絞り装置１４ａに冷媒が流れるように、インジェクション圧力Ｐm よりも高くなるように設定する。このため、計測制御装置１８は、熱源側絞り装置１１の冷媒流入口の飽和圧力と目標値とを比較する（ステップＳ１２）。そして、熱源側絞り装置１１の冷媒流入口の飽和圧力が目標値を含む所定範囲内であると判断すると、熱源側絞り装置１１の開度をそのまま維持するようにする。そして、ステップＳ２に戻って処理を続ける。また、熱源側絞り装置１１の冷媒流入口の飽和圧力が目標値より所定範囲の上限より高いと判断すると、熱源側絞り装置１１の開度を大きくし、熱源側絞り装置１１の冷媒流入口の飽和圧力が目標値より低いと判断すると、熱源側絞り装置１１の開度を小さくする負荷側絞り装置開度変更制御を行う（ステップＳ１３）。そして、ステップＳ２に戻って処理を続ける。 Next, the opening degree of the heat source side expansion device 11 is converted into the saturation pressure of the refrigerant flowing into the heat source side expansion device 11 from the temperature related to the detection by the temperature sensor 49. Then, control is performed so that the saturation pressure becomes a target value (for example, 2 MPa) that is a predetermined pressure set in advance. Here, the target value, as the refrigerant flows into the bypass throttle device 14a, set to be higher than the injection pressure P m. For this reason, the measurement control device 18 compares the saturation pressure at the refrigerant inlet of the heat source side expansion device 11 with the target value (step S12). If it is determined that the saturation pressure at the refrigerant inlet of the heat source side expansion device 11 is within a predetermined range including the target value, the opening degree of the heat source side expansion device 11 is maintained as it is. And it returns to step S2 and continues a process. When it is determined that the saturation pressure at the refrigerant inlet of the heat source side expansion device 11 is higher than the upper limit of the predetermined range from the target value, the opening degree of the heat source side expansion device 11 is increased, and the refrigerant inlet of the heat source side expansion device 11 is increased. If it is determined that the saturation pressure is lower than the target value, load side expansion device opening degree change control for reducing the opening amount of the heat source side expansion device 11 is performed (step S13). And it returns to step S2 and continues a process.

ここで、上述した説明においては熱源側絞り装置１１の飽和圧力の目標値をあらかじめ設定したものとしているが、この値は一定にする必要はない。例えば、圧力センサ５２の検知に係る高圧冷媒（圧縮機３の吐出側の冷媒）の圧力と熱源側絞り装置１１の飽和圧力との圧力差が所定の値（例えば０．３ＭＰａ）になるような目標値に設定できるようにしてもよい。このようにすることで、運転中の高圧圧力の状態によらず、バイパス絞り装置１４ａを通過する前後における差圧を確保することができ、インジェクションにおいて安定した冷媒供給を行うことが可能になる。   Here, in the above description, the target value of the saturation pressure of the heat source side expansion device 11 is set in advance, but this value need not be constant. For example, the pressure difference between the pressure of the high-pressure refrigerant (the refrigerant on the discharge side of the compressor 3) related to detection by the pressure sensor 52 and the saturation pressure of the heat source side expansion device 11 becomes a predetermined value (eg, 0.3 MPa). The target value may be set. By doing so, it is possible to ensure a differential pressure before and after passing through the bypass throttling device 14a regardless of the state of high pressure during operation, and it is possible to perform stable refrigerant supply in injection.

また、上述した説明においては、温度センサ４９の検知に係る温度を換算して熱源側絞り装置１１の飽和圧力を求めるようにしたが、温度センサ４９の代わりに圧力センサを設け、熱源側絞り装置１１に流入する冷媒の圧力を直接検知するようにしてもよい。   In the above description, the saturation pressure of the heat source side expansion device 11 is obtained by converting the temperature related to the detection by the temperature sensor 49. However, instead of the temperature sensor 49, a pressure sensor is provided, and the heat source side expansion device is obtained. You may make it detect the pressure of the refrigerant | coolant which flows in into 11 directly.

さらに、上述した説明においては、凝縮器となる室内熱交換器６の冷媒流出口の冷媒過冷却度ＳＣが目標値となるように負荷側絞り装置８の開度を制御している。このような開度制御を行うことで、凝縮器での熱交換性能を高く確保するとともに、冷媒エンタルピ差も適度に確保するように運転することができ、高効率の運転を行うことができる。このような運転を行うことができる凝縮器の冷媒流出口における冷媒過冷却度ＳＣは、熱交換器の特性によって異なるが、概ね、凝縮温度と、空気、水等の熱交換媒体との温度差の１／２程度の温度である５〜１０℃前後である。   Furthermore, in the above description, the opening degree of the load side expansion device 8 is controlled so that the refrigerant supercooling degree SC at the refrigerant outlet of the indoor heat exchanger 6 serving as a condenser becomes a target value. By performing such opening degree control, it is possible to ensure high heat exchanging performance in the condenser and to appropriately ensure the refrigerant enthalpy difference, and it is possible to perform highly efficient operation. The refrigerant supercooling degree SC at the refrigerant outlet of the condenser capable of performing such an operation varies depending on the characteristics of the heat exchanger, but is generally a temperature difference between the condensation temperature and a heat exchange medium such as air or water. It is about 5-10 degreeC which is a temperature of about 1/2 of these.

このとき、冷媒過冷却度ＳＣの目標値はこの値よりも高い値（例えば１０〜１５℃前後）に設定する。これにより、暖房能力を増加した運転も行うことができる。そこで、運転状況に応じて、冷媒過冷却度ＳＣの目標値を変更してもよい。例えば、装置起動時は高めの目標値に設定しておいて暖房能力を確保するようにし、室温が安定しているときには低めの目標値に設定して高効率の運転を行うようにすることができる。   At this time, the target value of the refrigerant supercooling degree SC is set to a value higher than this value (for example, around 10 to 15 ° C.). Thereby, the driving | running which increased the heating capability can also be performed. Therefore, the target value of the refrigerant supercooling degree SC may be changed according to the operating situation. For example, when starting up the device, a higher target value is set to ensure heating capacity, and when the room temperature is stable, a lower target value is set to perform high-efficiency operation. it can.

図８は冷房運転時に計測制御装置１８が行う制御動作を説明する図である。冷房運転時には、まず、圧縮機３の容量、熱源側絞り装置１１の開度、バイパス絞り装置１４ａの開度、負荷側絞り装置８の開度が初期値に設定される（ステップＳ１０１）。ここで、冷房運転の場合には、圧力損失を最小にするため、熱源側絞り装置１１の開度を、全開に固定維持する。そして、所定時間が経過したものと判断すると（ステップＳ１０２）、運転状態に応じて各アクチュエータを制御するため、以下の処理を行う。   FIG. 8 is a diagram illustrating a control operation performed by the measurement control device 18 during the cooling operation. During the cooling operation, first, the capacity of the compressor 3, the opening of the heat source side expansion device 11, the opening of the bypass expansion device 14a, and the opening of the load side expansion device 8 are set to initial values (step S101). Here, in the case of the cooling operation, in order to minimize the pressure loss, the opening degree of the heat source side expansion device 11 is fixed and maintained fully open. When it is determined that the predetermined time has elapsed (step S102), the following processing is performed to control each actuator according to the operating state.

インジェクション圧力Ｐm を、圧縮機吐出圧力Ｐd 、圧縮機吸入圧力Ｐs から演算等により推測する（ステップＳ１０３）。そして、インジェクション圧力Ｐm 、圧縮機３の運転容量から得られるＣＯＰの大きさに基づいて、インジェクションバイパスを行うか吸入バイパスを行うかを決定し、流路切替弁１６ａによる流路設定を行う（ステップＳ１０４）。 The injection pressure P m is estimated by calculation or the like from the compressor discharge pressure P d and the compressor suction pressure P s (step S103). Then, based on the injection pressure P m and the COP obtained from the operating capacity of the compressor 3, it is determined whether injection bypass or suction bypass is to be performed, and the flow path setting by the flow path switching valve 16a is performed ( Step S104).

また、圧縮機３の容量について、基本的に室内機２の温度センサ４１の計測に係る空気温度が、空気調和装置を使用する者が設定する温度になるような制御を行う。このため、温度センサ４１の計測に係る空気温度と使用者による設定値とを比較する（ステップＳ１０５）。そして、空気温度が設定値を含む所定範囲内であると判断すると、圧縮機３の容量をそのまま維持するようにし、次のステップＳ１０７に進む。また、空気温度が所定範囲の下限より低いと判断すると、圧縮機３の容量を減少し、空気温度が所定範囲の上限より高いと判断すると、圧縮機３の容量を増加する圧縮機容量変更制御を行い（ステップＳ１０６）、次のステップＳ１０７に進む。   Further, the capacity of the compressor 3 is basically controlled so that the air temperature related to the measurement by the temperature sensor 41 of the indoor unit 2 becomes a temperature set by a person using the air conditioner. For this reason, the air temperature which concerns on the measurement of the temperature sensor 41, and the setting value by a user are compared (step S105). When it is determined that the air temperature is within a predetermined range including the set value, the capacity of the compressor 3 is maintained as it is, and the process proceeds to the next step S107. Further, when it is determined that the air temperature is lower than the lower limit of the predetermined range, the capacity of the compressor 3 is decreased, and when it is determined that the air temperature is higher than the upper limit of the predetermined range, the compressor capacity change control for increasing the capacity of the compressor 3. (Step S106), the process proceeds to the next step S107.

各絞り装置の開度制御は以下のように行う。まず、負荷側絞り装置８の開度については、圧力センサ５１の検知に係る低圧冷媒の圧力から飽和温度に換算する。そして、飽和温度と温度センサ４２の検知に係る室内熱交換器６の冷媒流出口の温度との温度差となる室内熱交換器６の冷媒流出口における冷媒過熱度ＳＨが予め設定された目標値（例えば３℃）になるように開度を制御する。このため、室内熱交換器６の冷媒流出口の冷媒過熱度ＳＨと目標値とを比較する（ステップＳ１０７）。そして、室内熱交換器６の冷媒流出口における冷媒過熱度ＳＨが目標値を含む所定範囲内であると判断すると、負荷側絞り装置８の開度をそのまま維持するようにし、次のステップＳ１０９に進む。また、室内熱交換器６の冷媒流出口における冷媒過熱度ＳＨが所定範囲の上限より大きいと判断すると、負荷側絞り装置８の開度を小さくし、冷媒過熱度ＳＨが所定範囲の下限より小さいと判断すると、負荷側絞り装置８の開度を大きくする負荷側絞り装置開度変更制御を行い（ステップＳ１０８）、次のステップに進む。   The opening control of each expansion device is performed as follows. First, the opening degree of the load side expansion device 8 is converted from the pressure of the low-pressure refrigerant related to the detection by the pressure sensor 51 to the saturation temperature. And the target value by which refrigerant | coolant superheat degree SH in the refrigerant | coolant outflow port of the indoor heat exchanger 6 used as a temperature difference with saturation temperature and the temperature of the refrigerant | coolant outflow port of the indoor heat exchanger 6 detected by the temperature sensor 42 was preset. The opening degree is controlled to be (for example, 3 ° C.). Therefore, the refrigerant superheat degree SH at the refrigerant outlet of the indoor heat exchanger 6 is compared with the target value (step S107). When it is determined that the refrigerant superheat degree SH at the refrigerant outlet of the indoor heat exchanger 6 is within a predetermined range including the target value, the opening degree of the load side expansion device 8 is maintained as it is, and the next step S109 is performed. move on. If it is determined that the refrigerant superheat degree SH at the refrigerant outlet of the indoor heat exchanger 6 is larger than the upper limit of the predetermined range, the opening degree of the load side expansion device 8 is reduced, and the refrigerant superheat degree SH is smaller than the lower limit of the predetermined range. Is determined, load side throttle device opening degree change control for increasing the opening degree of the load side throttle device 8 is performed (step S108), and the process proceeds to the next step.

次に、バイパス絞り装置１４ａの開度については、高効率運転をはかることと冷凍機油の劣化防止をはかることとに基づいて制御を行う。温度センサ４８ａの検知に係る内部熱交換器９ａの冷媒流出口の温度と温度センサ４７ａの検知に係る内部熱交換器９ａに流入するバイパス絞り装置１４ａを通過した低圧側の冷媒の飽和温度との温度差となる内部熱交換器９ａの冷媒流出口の冷媒過熱度ＳＨが、予め設定された目標値（例えば３℃）になるように開度を制御する。このため、内部熱交換器９ａの冷媒流出口の冷媒過冷却度ＳＣと目標値とを比較する（ステップＳ１０９）。そして、内部熱交換器９ａの冷媒流出口の冷媒過冷却度ＳＣが目標値を含む所定範囲内であると判断すると、バイパス絞り装置１４ａの開度をそのまま維持するようにし、次のステップＳ１１１に進む。また、内部熱交換器９ａの冷媒流出口の冷媒過冷却度ＳＣが所定範囲の上限より大きいと判断すると、バイパス絞り装置１４ａの開度を大きくし、冷媒過冷却度ＳＣが所定範囲の下限より小さいと判断すると、バイパス絞り装置１４ａの開度を小さくするバイパス絞り装置開度変更制御を行い（ステップＳ１１０）、ステップＳ１０２に戻る。   Next, the opening degree of the bypass expansion device 14a is controlled based on the high efficiency operation and the prevention of deterioration of the refrigerating machine oil. The temperature of the refrigerant outlet of the internal heat exchanger 9a related to the detection of the temperature sensor 48a and the saturation temperature of the low-pressure side refrigerant that has passed through the bypass expansion device 14a flowing into the internal heat exchanger 9a related to the detection of the temperature sensor 47a. The degree of opening is controlled so that the refrigerant superheat degree SH at the refrigerant outlet of the internal heat exchanger 9a that becomes a temperature difference becomes a preset target value (for example, 3 ° C.). For this reason, the refrigerant supercooling degree SC at the refrigerant outlet of the internal heat exchanger 9a is compared with the target value (step S109). When it is determined that the refrigerant supercooling degree SC at the refrigerant outlet of the internal heat exchanger 9a is within a predetermined range including the target value, the opening degree of the bypass expansion device 14a is maintained as it is, and the next step S111 is performed. move on. If it is determined that the refrigerant supercooling degree SC at the refrigerant outlet of the internal heat exchanger 9a is larger than the upper limit of the predetermined range, the opening degree of the bypass expansion device 14a is increased, and the refrigerant subcooling degree SC is lower than the lower limit of the predetermined range. If it is determined that the opening is small, bypass opening device opening change control for reducing the opening of the bypass expansion device 14a is performed (step S110), and the process returns to step S102.

さらに、バイパス絞り装置１４ａは、圧縮機３の吐出温度上昇による冷凍機油の劣化防止のための開度制御を行う。温度センサ４６の検知に係る圧縮機３の吐出温度が、予め設定された設定値（例えば１００℃）以下になるように制御される。このため、温度センサ４６の検知に係る圧縮機３の吐出温度と設定値とを比較する（ステップＳ１１１）。そして、圧縮機３の吐出温度が設定値以下であると判断すると、バイパス絞り装置１４ａの開度をそのまま維持するようにし、ステップＳ１０２に戻る。また、圧縮機３の吐出温度が設定値より高い吐判断すると、バイパス絞り装置１４ａの開度を大きくするバイパス絞り装置開度変更制御を行い（ステップＳ１１０）、ステップＳ１０２に戻る。   Further, the bypass expansion device 14 a performs opening degree control for preventing deterioration of the refrigerating machine oil due to an increase in the discharge temperature of the compressor 3. The discharge temperature of the compressor 3 according to the detection of the temperature sensor 46 is controlled to be equal to or lower than a preset value (for example, 100 ° C.). For this reason, the discharge temperature of the compressor 3 according to the detection of the temperature sensor 46 is compared with the set value (step S111). And if it judges that the discharge temperature of the compressor 3 is below a preset value, it will maintain the opening degree of the bypass expansion apparatus 14a as it is, and will return to step S102. If it is determined that the discharge temperature of the compressor 3 is higher than the set value, bypass throttling device opening change control for increasing the opening of the bypass throttling device 14a is performed (step S110), and the process returns to step S102.

ここで、圧縮機３の吐出温度の設定値は、吐出温度そのものでなくてもよく、圧縮機３の吐出温度と圧縮機３の吐出圧力から換算される飽和温度との温度差である圧縮機３の吐出過熱度に基づいて設定してもよい。   Here, the set value of the discharge temperature of the compressor 3 may not be the discharge temperature itself, but a compressor that is a temperature difference between the discharge temperature of the compressor 3 and the saturation temperature converted from the discharge pressure of the compressor 3. 3 may be set based on the degree of discharge superheat.

また、内部熱交換器９ａの配置位置は、図１に係る構成の位置に限るものではない。例えば、上流下流の位置関係が反対であっても同様の効果を得ることができる。また、バイパス配管１７ａを接続する位置も図１の位置に限るものではなく、他の中間圧部分、高圧液部から冷媒を分岐させることができる位置であれば同様の効果を得ることができる。このとき、バイパス絞り装置１４ａの制御安定性を考慮すると、気液二相状態の冷媒を分岐する位置であるよりは、完全に液の状態となった冷媒を分岐できる位置にバイパス配管１７ａを接続する方が望ましい。   Further, the arrangement position of the internal heat exchanger 9a is not limited to the position of the configuration according to FIG. For example, the same effect can be obtained even if the upstream and downstream positional relationships are opposite. Further, the position where the bypass pipe 17a is connected is not limited to the position shown in FIG. 1, and the same effect can be obtained as long as the refrigerant can be branched from other intermediate pressure portions and high pressure liquid portions. At this time, in consideration of the control stability of the bypass throttle device 14a, the bypass pipe 17a is connected to a position where the refrigerant in the liquid state can be branched rather than the position where the refrigerant in the gas-liquid two-phase state is branched. Is preferable.

以上のように実施の形態１の空気調和装置によれば、流路切替弁１６ａにより、圧縮機のインジェクションポートから冷媒を流入させるか圧縮機３の吸入側に冷媒を流すかを選択することができる。このため、冷房運転、暖房運転等の様々な運転状態に応じて、バイパス絞り装置１４ａの開度を調整しながら流路切替冷媒回路２０に冷媒をバイパスさせることで、高効率な運転を実現可能な空気調和装置を得ることができる。   As described above, according to the air conditioning apparatus of the first embodiment, the flow path switching valve 16a can be used to select whether the refrigerant flows from the injection port of the compressor or the refrigerant flows to the suction side of the compressor 3. it can. Therefore, highly efficient operation can be realized by bypassing the refrigerant to the flow path switching refrigerant circuit 20 while adjusting the opening of the bypass expansion device 14a according to various operation states such as cooling operation and heating operation. A simple air conditioner can be obtained.

また、圧縮機３における圧縮機運転容量とインジェクション圧力に基づいて、流路切替弁１６ａの流路設定を行ってインジェクションバイパス回路とするか吸入バイパス回路とするかを選択できるようにしたので、ＣＯＰの高い高効率の運転を行うことができる。このとき、圧縮機３の吐出圧力及び吸入圧力からインジェクション圧力を導き出すことで、より正確なインジェクション圧力を得ることができる。さらに、内部熱交換器９ａの冷媒過熱度ＳＨが目標値が示す所定温度となるように、圧縮機３の冷媒吐出温度等が所定の温度となるようにバイパス絞り装置１４ａの開度を制御するようにしたので、効率よく、また冷凍機油の保護を図りつつ運転を行うことができる。また、暖房運転時には、温度センサ４９の検知に係る温度から換算した熱源側絞り装置１１に流入する冷媒の圧力等に基づき、熱源側絞り装置１１の開度を制御するようにしたので、蒸発器となる室外熱交換器１２を通過する冷媒量を制御することができ、効率よく運転することができる。   In addition, since it is possible to select the injection bypass circuit or the suction bypass circuit by setting the flow path of the flow path switching valve 16a based on the compressor operating capacity and the injection pressure in the compressor 3, the COP High efficiency operation. At this time, a more accurate injection pressure can be obtained by deriving the injection pressure from the discharge pressure and the suction pressure of the compressor 3. Further, the opening degree of the bypass expansion device 14a is controlled so that the refrigerant discharge temperature of the compressor 3 becomes a predetermined temperature so that the refrigerant superheat degree SH of the internal heat exchanger 9a becomes a predetermined temperature indicated by the target value. Since it did in this way, it can operate | move efficiently and aiming at protection of refrigeration oil. Further, during the heating operation, the opening degree of the heat source side expansion device 11 is controlled based on the pressure of the refrigerant flowing into the heat source side expansion device 11 converted from the temperature related to the detection by the temperature sensor 49, so that the evaporator Thus, the amount of refrigerant passing through the outdoor heat exchanger 12 can be controlled, and operation can be performed efficiently.

ここで、本実施の形態では、熱源側絞り装置１１と負荷側絞り装置８との間に内部熱交換器９ａ、及びバイパス絞り装置１４ａ、流路切替弁１６ａを配置しているので、冷暖いずれの運転モードでも、同様のインジェクションバイパスや吸入バイパスを行った運転を選択的に行うことができる。また、図１では高低圧を検知する圧力センサを設け、冷媒の飽和温度を検知する構成としているが、凝縮器、蒸発器中間の冷媒温度センサで飽和温度を検知してもよい。   Here, in the present embodiment, the internal heat exchanger 9a, the bypass expansion device 14a, and the flow path switching valve 16a are arranged between the heat source side expansion device 11 and the load side expansion device 8, so Even in this operation mode, it is possible to selectively perform the operation with the same injection bypass and suction bypass. In FIG. 1, a pressure sensor for detecting high and low pressures is provided to detect the saturation temperature of the refrigerant, but the saturation temperature may be detected by a refrigerant temperature sensor between the condenser and the evaporator.

実施の形態２．
図９は本発明に係る実施の形態２の空気調和装置１００の構成を示す図である。図９において、図１等と同じ番号を付している機器等については、実施の形態１で説明したことと同様の動作を行う。図９に示すように、実施の形態２では、図１に記載した流路切替冷媒回路２０を２つ設置している。一方の流路切替冷媒回路２０において、図１の内部熱交換器９ａ、バイパス絞り装置１４ａ、流路切替弁１６ａ等のように、添え字「ａ」を記載したものと同じ機能等を有する他方の流路切替冷媒回路２０の機器等は、添え字に「ｂ」を記載して示している。 Embodiment 2. FIG.
FIG. 9 is a diagram showing the configuration of the air-conditioning apparatus 100 according to Embodiment 2 of the present invention. In FIG. 9, the same reference numerals as those in FIG. 1 and the like perform the same operations as those described in the first embodiment. As shown in FIG. 9, in the second embodiment, two flow path switching refrigerant circuits 20 shown in FIG. 1 are installed. In the one flow path switching refrigerant circuit 20, the other having the same function as the one described with the subscript “a”, such as the internal heat exchanger 9a, the bypass expansion device 14a, the flow path switching valve 16a in FIG. The devices and the like of the flow path switching refrigerant circuit 20 are indicated by subscript “b”.

本実施の形態では、流路切替冷媒回路２０を２つ配設した構成とし、流路切替弁１６ａ、１６ｂをそれぞれ切り替えることによって、インジェクションバイパス回路、吸入バイパス回路を別々に行ったり、併用したりして運転することができる。   In the present embodiment, two flow path switching refrigerant circuits 20 are arranged, and by switching the flow path switching valves 16a and 16b, the injection bypass circuit and the suction bypass circuit are separately performed or used together. And can drive.

本実施の形態の空気調和装置１００においても、実施の形態１と同様に、冷房、暖房いずれの運転でも同様の運転を行うことができる。ここでは暖房運転について説明する。図９の空気調和装置１００において、流路切替弁１６ａを実線で表す流路、流路切替弁１６ｂを破線で表す流路に設定した場合、バイパス配管１７ａを流通する流路は、インジェクションバイパス回路となり、バイパス配管１７ｂを流通する流路は、吸入バイパス回路となる。このように、例えば、主冷媒回路の冷媒の流れに対して上流側となる位置にバイパス配管１７の一端が接続されている流路切替冷媒回路２０をインジェクションバイパス回路とする。そして、下流となる位置にバイパス配管１７の一端が接続されている流路切替冷媒回路２０を吸入バイパス回路とする。   Also in the air conditioning apparatus 100 of the present embodiment, similar to the first embodiment, the same operation can be performed in both the cooling operation and the heating operation. Here, the heating operation will be described. In the air conditioner 100 of FIG. 9, when the flow path switching valve 16a is set to a flow path represented by a solid line and the flow path switching valve 16b is set to a flow path represented by a broken line, the flow path through the bypass pipe 17a is an injection bypass circuit. Thus, the flow path flowing through the bypass pipe 17b is a suction bypass circuit. Thus, for example, the flow path switching refrigerant circuit 20 in which one end of the bypass pipe 17 is connected to a position on the upstream side with respect to the refrigerant flow of the main refrigerant circuit is referred to as an injection bypass circuit. The flow path switching refrigerant circuit 20 in which one end of the bypass pipe 17 is connected to the downstream position is referred to as an intake bypass circuit.

ここで、室内機２から液管７を経由する冷媒を、インジェクションバイパス回路の内部熱交換器９ａ、吸入バイパス回路の内部熱交換器９ｂを通過するようにそれぞれ流路切替弁１６ａ、１６ｂを設定する。これにより内部熱交換器９ａ、９ｂを経由する過程で、熱源側絞り装置１１に流入する冷媒の温度が徐々に冷却される。このため、冷媒間の温度差が小さい状態で熱交換可能であり、熱交換効率が高くなり、内部熱交換器９ａ、９ｂを有効に利用できるという特徴がある。   Here, the flow path switching valves 16a and 16b are set so that the refrigerant passing through the liquid pipe 7 from the indoor unit 2 passes through the internal heat exchanger 9a of the injection bypass circuit and the internal heat exchanger 9b of the suction bypass circuit. To do. Thereby, the temperature of the refrigerant flowing into the heat source side expansion device 11 is gradually cooled in the process of passing through the internal heat exchangers 9a and 9b. For this reason, heat exchange is possible in a state where the temperature difference between the refrigerants is small, heat exchange efficiency is increased, and the internal heat exchangers 9a and 9b can be effectively used.

図１０は圧縮機３の運転容量が高いときのインジェクション内部熱交換器容量比率に対するＣＯＰ向上率を表す概念図である。ここで、内部熱交換器容量とは、熱コンダクタンスを表すものであり、伝熱面積と熱通過率の積に相当するものである。そして、インジェクション内部熱交換器容量比率とは、インジェクションバイパスに係る内部熱交換器（本実施の形態では内部熱交換器９ａ）と吸入バイパスに係る内部熱交換器（本実施の形態では内部熱交換器９ｂ）との熱交換容量の和に対するインジェクションバイパスに係る内部熱交換器の熱交換容量の割合を表すものとする。   FIG. 10 is a conceptual diagram showing the COP improvement rate with respect to the injection internal heat exchanger capacity ratio when the operating capacity of the compressor 3 is high. Here, the internal heat exchanger capacity represents thermal conductance and corresponds to the product of the heat transfer area and the heat transfer rate. The injection internal heat exchanger capacity ratio is the internal heat exchanger related to the injection bypass (in this embodiment, the internal heat exchanger 9a) and the internal heat exchanger related to the suction bypass (in this embodiment, the internal heat exchange). The ratio of the heat exchange capacity of the internal heat exchanger according to the injection bypass to the sum of the heat exchange capacity with the vessel 9b) shall be expressed.

図１０より、インジェクション内部熱交換器容積比率が大きいほど、インジェクションバイパスによるＣＯＰ向上率が大きくなる。逆にインジェクション内部熱交換器容積比率が小さい場合は、吸入バイパスでの熱交換器容量が大きくなるため、吸入バイパスによるＣＯＰ向上率が大きくなる。したがって、それぞれのＣＯＰ向上率の合成効果として、最大ＣＯＰとなるインジェクション熱交換容量比率が存在する。図９の空気調和装置１００の場合、内部熱交換器９ａと内部熱交換器９ｂとの熱交換器容量の比率が、６：４程度であるときが最もＣＯＰが高くなる。そこで、例えば、内部熱交換器９ａ、９ｂが二重管熱交換器でそれぞれの配管サイズが同一の場合、二重管の長さを６：４となるように予め設定することで圧縮機３の運転容量が高い場合において高効率な運転を実現することが可能となる。   From FIG. 10, the larger the injection internal heat exchanger volume ratio, the larger the COP improvement rate due to the injection bypass. Conversely, when the volume ratio of the internal heat exchanger for injection is small, the capacity of the heat exchanger in the suction bypass increases, and the COP improvement rate due to the suction bypass increases. Therefore, there is an injection heat exchange capacity ratio that gives the maximum COP as a combined effect of the respective COP improvement rates. In the case of the air conditioner 100 of FIG. 9, the COP is highest when the ratio of the heat exchanger capacity between the internal heat exchanger 9a and the internal heat exchanger 9b is about 6: 4. Therefore, for example, when the internal heat exchangers 9a and 9b are double pipe heat exchangers and the pipe sizes are the same, the length of the double pipe is set in advance to be 6: 4, so that the compressor 3 It is possible to realize highly efficient operation when the operating capacity of the vehicle is high.

図１１は圧縮機３の運転容量が低いときのインジェクション内部熱交換器容量比率に対するＣＯＰ向上率を表す概念図である。   FIG. 11 is a conceptual diagram showing the COP improvement rate with respect to the injection internal heat exchanger capacity ratio when the operating capacity of the compressor 3 is low.

図１１より、圧縮機３の運転容量が低い場合は、蒸発器となる熱交換器及び蒸発器から圧縮機３の吸入側までの配管における圧力損失が小さいため、吸入バイパスによる圧力損失低減によるＣＯＰ向上率の効果が小さくなる。このため、インジェクションバイパス回路側の内部熱交換器９における内部熱交換器容量の比率が大きいほど、インジェクションバイパスのＣＯＰと吸入バイパスとのＣＯＰ向上率の合成効果は大きくなる。したがって、図９の空気調和装置１００において、流路切替弁１６ａ、１６ｂにおける冷媒の流路が図９の実線方向となるように設定し、２つの流路切替冷媒回路２０がともにインジェクションバイパスとなるようにする。これにより、圧縮機の運転容量が低い場合においてＣＯＰを大きくした運転を実現することができる。   From FIG. 11, when the operating capacity of the compressor 3 is low, the pressure loss in the heat exchanger as an evaporator and the piping from the evaporator to the suction side of the compressor 3 is small. The effect of the improvement rate is reduced. For this reason, the larger the ratio of the internal heat exchanger capacity in the internal heat exchanger 9 on the injection bypass circuit side, the greater the combined effect of the COP improvement rate of the COP of the injection bypass and the suction bypass. Therefore, in the air conditioner 100 of FIG. 9, the refrigerant flow paths in the flow path switching valves 16a and 16b are set to be in the direction of the solid line in FIG. 9, and the two flow path switching refrigerant circuits 20 are both injection bypasses. Like that. Thereby, when the operating capacity of the compressor is low, it is possible to realize an operation in which the COP is increased.

また、図示していないが、圧縮機３の吸入圧力Ｐs を高く、インジェクション圧力Ｐm を高くする場合は、前述のようにインジェクションによるＣＯＰ向上率が低下するため、吸入バイパスによるＣＯＰ向上率が相対的に高くなる。このため、インジェクション内部熱交換器容量比率が小さいほど、インジェクションバイパスのＣＯＰと吸入バイパスとのＣＯＰ向上率の合成効果は大きくなる。したがって、図９の空気調和装置１００において、流路切替弁１６ａ、１６ｂにおける冷媒の流路が図９の破線方向となるように設定し、２つの流路切替冷媒回路２０がともに吸入バイパスとなるようにする。これにより、インジェクション圧力Ｐm が高い場合においてＣＯＰを大きくした運転を実現することができる。 Although not shown, when the suction pressure P s of the compressor 3 is increased and the injection pressure P m is increased, the COP improvement rate due to the injection decreases as described above. Relatively high. For this reason, the smaller the injection internal heat exchanger capacity ratio is, the greater the combined effect of the COP improvement rate of the COP of the injection bypass and the suction bypass. Therefore, in the air conditioner 100 of FIG. 9, the refrigerant flow paths in the flow path switching valves 16a and 16b are set so as to be in the direction of the broken line in FIG. 9, and the two flow path switching refrigerant circuits 20 are both suction bypass. Like that. Thereby, when the injection pressure Pm is high, an operation with a large COP can be realized.

以上のように、実施の形態２の空気調和装置１００によれば、流路切替冷媒回路２０を複数配置し、それぞれインジェクションバイパス回路として機能するか又は吸入バイパスとして機能するかを選択することができるようにしたので、両回路を組み合わせて効率のよい運転を行うことができる。このとき、流路切替冷媒回路２０において、内部熱交換器９の熱交換器容量を異ならせるようにしたので、インジェクション内部熱交換器容量比率を細分化する等によって、空調負荷や運転状態に応じて柔軟に対応してＣＯＰを大きくし、高効率の運転を実現することができる。そして、インジェクションバイパス回路となる方を、主冷媒回路において流れる冷媒に対して上流側に位置するようにすることで、インジェクションバイパス回路に流れる冷媒量を優先して調整等することができる。   As described above, according to the air conditioning apparatus 100 of the second embodiment, a plurality of flow path switching refrigerant circuits 20 can be arranged, and each of them can be selected to function as an injection bypass circuit or a suction bypass. As a result, efficient operation can be performed by combining both circuits. At this time, since the heat exchanger capacity of the internal heat exchanger 9 is made different in the flow path switching refrigerant circuit 20, depending on the air conditioning load and the operating state by subdividing the injection internal heat exchanger capacity ratio, etc. Therefore, the COP can be increased flexibly and high-efficiency operation can be realized. And the direction which becomes an injection bypass circuit is located upstream with respect to the refrigerant | coolant which flows in a main refrigerant circuit, and can preferentially adjust the refrigerant | coolant amount which flows into an injection bypass circuit.

実施の形態３．
上述の実施の形態では、空気調和装置１００に室外機１、室内機２をそれぞれ１台搭載した場合を例として説明したが、これに限定するものではない。例えば、空気調和装置１００に室外機１を複数台搭載する、室内機２を複数台搭載する等の構成としても同様の効果を奏することができる。 Embodiment 3 FIG.
In the above-described embodiment, the case where one outdoor unit 1 and one indoor unit 2 are mounted on the air conditioner 100 has been described as an example. However, the present invention is not limited to this. For example, the same effect can be achieved by a configuration in which a plurality of outdoor units 1 are mounted on the air conditioner 100 and a plurality of indoor units 2 are mounted.

また、上述の実施の形態では、ルームエアコン、パッケージエアコン等の空気調和装置１００として説明した。本発明は、冷暖房運転等多様な運転を行うことができる空気調和装置に特に有効であるが、例えば、冷凍装置、冷蔵庫、加湿器、調湿装置、ヒートポンプ給湯器等の冷凍サイクル装置に適用することも可能である。   In the above-described embodiment, the air conditioner 100 such as a room air conditioner or a packaged air conditioner has been described. The present invention is particularly effective for an air conditioner capable of performing various operations such as an air conditioning operation, and is applied to a refrigeration cycle apparatus such as a refrigeration apparatus, a refrigerator, a humidifier, a humidity control apparatus, and a heat pump water heater. It is also possible.

１ 室外機、２ 室内機、３ 圧縮機、４ 四方弁、５ ガス管、６ 室内熱交換器、７ 液管、８ 負荷側絞り装置、９ａ，９ｂ 内部熱交換器、１１ 熱源側絞り装置、１２ 室外熱交換器、１３ａ，１３ｂ インジェクションバイパス配管、１４ａ，１４ｂ バイパス絞り装置、１５ａ，１５ｂ 吸入バイパス配管、１６ａ，１６ｂ 流路切替弁、１７ａ、１７ｂ バイパス配管、１８ 計測制御装置、２０ 流路切替冷媒回路、４１，４２，４３，４４，４５，４６，４７ａ，４７ｂ，４８ａ，４８ｂ，４９ 温度センサ、５１，５２ 圧力センサ、１００ 空気調和装置。   DESCRIPTION OF SYMBOLS 1 Outdoor unit, 2 Indoor unit, 3 Compressor, 4 Four way valve, 5 Gas pipe, 6 Indoor heat exchanger, 7 Liquid pipe, 8 Load side throttle device, 9a, 9b Internal heat exchanger, 11 Heat source side throttle device, 12 outdoor heat exchanger, 13a, 13b injection bypass piping, 14a, 14b bypass throttle device, 15a, 15b suction bypass piping, 16a, 16b channel switching valve, 17a, 17b bypass piping, 18 measurement control device, 20 channel switching Refrigerant circuit, 41, 42, 43, 44, 45, 46, 47a, 47b, 48a, 48b, 49 Temperature sensor, 51, 52 Pressure sensor, 100 Air conditioner.

Claims (8)

吸入した冷媒を圧縮して吐出する圧縮行程の中間部分に冷媒通過口となるインジェクションポートを有する圧縮機、四方弁、熱源側絞り装置、熱源側熱交換器、負荷側絞り装置及び負荷側熱交換器を環状に接続して冷媒を循環させる主冷媒回路を構成し、
前記主冷媒回路から分岐した冷媒の減圧を行うバイパス絞り装置と、
該バイパス絞り装置を通過した冷媒と前記主冷媒回路を通過する冷媒との熱交換を行う内部熱交換器と、
該内部熱交換器が熱交換した冷媒を、前記インジェクションポートに接続された配管又は前記圧縮機の吸入側に接続された配管のいずれかに流すための流路設定を行う流路切替手段と
を有する１以上の流路切替冷媒回路をさらに備えることを特徴とする空気調和装置。 Compressor having an injection port serving as a refrigerant passage in the middle part of the compression stroke for compressing and discharging the sucked refrigerant, four-way valve, heat source side throttle device, heat source side heat exchanger, load side throttle device, and load side heat exchange A main refrigerant circuit that circulates the refrigerant by connecting the vessel in an annular shape,
A bypass throttle device for depressurizing the refrigerant branched from the main refrigerant circuit;
An internal heat exchanger that performs heat exchange between the refrigerant that has passed through the bypass throttle device and the refrigerant that has passed through the main refrigerant circuit;
A flow path switching means for setting a flow path for flowing the refrigerant heat-exchanged by the internal heat exchanger to either a pipe connected to the injection port or a pipe connected to the suction side of the compressor; An air conditioner further comprising one or more flow path switching refrigerant circuits. 前記流路切替冷媒回路を２以上備える場合に、少なくとも１つの前記内部熱交換器における熱交換器容量が、他の内部熱交換器と異なる熱交換器容量であることを特徴とする請求項１に記載の空気調和装置。   The heat exchanger capacity of at least one of the internal heat exchangers is a heat exchanger capacity different from other internal heat exchangers when two or more of the flow path switching refrigerant circuits are provided. The air conditioning apparatus described in 1. 前記インジェクションポートにおける冷媒の圧力と前記圧縮機の運転容量とに基づいて、前記流路切替手段に設定させる流路を選択する制御装置をさらに備えることを特徴とする請求項１又は２に記載の空気調和装置。   3. The control device according to claim 1, further comprising: a control device that selects a flow path to be set by the flow path switching unit based on a refrigerant pressure in the injection port and an operating capacity of the compressor. Air conditioner. 前記圧縮機の吸入圧力と吐出圧力とから前記インジェクションポートにおける圧力を推測する制御装置をさらに備えることを特徴とする請求項３に記載の空気調和装置。   The air conditioning apparatus according to claim 3, further comprising a control device that estimates pressure in the injection port from suction pressure and discharge pressure of the compressor. 前記主冷媒回路の冷媒の流れに対して上流側に位置する前記流路切替冷媒回路を流れる冷媒が前記インジェクションポートに流れ、下流側に位置する前記流路切替冷媒回路を流れる冷媒が前記圧縮機の吸入側に流れるように、各流路切替冷媒回路における前記流路切替手段の流路設定を行うことを特徴とする請求項１〜４のいずれかに記載の空気調和装置。   The refrigerant flowing through the flow path switching refrigerant circuit located upstream with respect to the flow of refrigerant in the main refrigerant circuit flows to the injection port, and the refrigerant flowing through the flow path switching refrigerant circuit located downstream is the compressor. The air conditioner according to any one of claims 1 to 4, wherein a flow path setting of the flow path switching means in each flow path switching refrigerant circuit is performed so as to flow to the suction side of the air. 前記内部熱交換器の冷媒過熱度が所定の温度となるように前記バイパス絞り装置の開度を制御する制御装置をさらに備えることを特徴とする請求項１〜５のいずれかに記載の空気調和装置。   The air conditioning according to any one of claims 1 to 5, further comprising a control device that controls an opening degree of the bypass throttling device so that a degree of refrigerant superheating of the internal heat exchanger becomes a predetermined temperature. apparatus. 前記圧縮機の冷媒吐出温度又は前記圧縮機が吐出する過熱度が所定の温度となるように前記バイパス絞り装置の開度を制御する制御装置をさらに備えることを特徴とする請求項１〜６のいずれかに記載の空気調和装置。   The control apparatus which controls the opening degree of the said bypass throttle apparatus so that the refrigerant | coolant discharge temperature of the said compressor or the superheat degree which the said compressor discharges may become predetermined | prescribed temperature is further provided. The air conditioning apparatus in any one. 前記熱源側絞り装置に流入する冷媒の圧力又は前記圧縮機から吐出する冷媒と前記熱源側絞り装置に流入する冷媒との圧力差が、所定の圧力となるように前記熱源側絞り装置の開度を制御する制御装置をさらに備えることを特徴とする請求項１〜７のいずれかに記載の空気調和装置。   The degree of opening of the heat source side expansion device so that the pressure of the refrigerant flowing into the heat source side expansion device or the pressure difference between the refrigerant discharged from the compressor and the refrigerant flowing into the heat source side expansion device becomes a predetermined pressure. The air conditioner according to any one of claims 1 to 7, further comprising a control device for controlling the air conditioner.
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Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20140123821A (en) * 2013-04-15 2014-10-23 엘지전자 주식회사 Air Conditioner and Controlling method for the same
WO2014188984A1 (en) * 2013-05-20 2014-11-27 サンデン株式会社 Vehicle air conditioner
CN104251518A (en) * 2013-06-25 2014-12-31 三菱电机株式会社 Air conditioning device
JP2015068614A (en) * 2013-09-30 2015-04-13 ダイキン工業株式会社 Refrigeration unit
JP2015087020A (en) * 2013-10-28 2015-05-07 三菱電機株式会社 Refrigeration cycle device
JP2015127637A (en) * 2015-04-09 2015-07-09 三菱電機株式会社 Air conditioning device
JP2016148510A (en) * 2016-04-07 2016-08-18 三菱電機株式会社 Air conditioner
JPWO2016166845A1 (en) * 2015-04-15 2017-12-14 三菱電機株式会社 Refrigeration cycle equipment
JP2018021730A (en) * 2016-08-05 2018-02-08 日立ジョンソンコントロールズ空調株式会社 Refrigeration cycle device
JP7450745B2 (en) 2020-03-06 2024-03-15 ダイキン工業株式会社 Heat pump systems and methods for controlling heat pump systems
US11945283B2 (en) 2022-04-15 2024-04-02 Hyundai Motor Company Thermal management system of gas injection type for vehicle
JP7478967B2 (en) 2020-02-25 2024-05-08 パナソニックＩｐマネジメント株式会社 Air Conditioning Equipment

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007178029A (en) * 2005-12-27 2007-07-12 Mitsubishi Electric Corp Refrigerating air conditioner
JP2007205596A (en) * 2006-01-31 2007-08-16 Sanyo Electric Co Ltd Air conditioner
JP2007263443A (en) * 2006-03-28 2007-10-11 Mitsubishi Electric Corp Air conditioner
JP2009204244A (en) * 2008-02-28 2009-09-10 Daikin Ind Ltd Refrigerating device
JP2010139205A (en) * 2008-12-15 2010-06-24 Mitsubishi Electric Corp Air conditioning device
JP2010531423A (en) * 2006-12-29 2010-09-24 キャリア コーポレイション Economizer heat exchanger

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007178029A (en) * 2005-12-27 2007-07-12 Mitsubishi Electric Corp Refrigerating air conditioner
JP2007205596A (en) * 2006-01-31 2007-08-16 Sanyo Electric Co Ltd Air conditioner
JP2007263443A (en) * 2006-03-28 2007-10-11 Mitsubishi Electric Corp Air conditioner
JP2010531423A (en) * 2006-12-29 2010-09-24 キャリア コーポレイション Economizer heat exchanger
JP2009204244A (en) * 2008-02-28 2009-09-10 Daikin Ind Ltd Refrigerating device
JP2010139205A (en) * 2008-12-15 2010-06-24 Mitsubishi Electric Corp Air conditioning device

Cited By (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR102103360B1 (en) 2013-04-15 2020-05-29 엘지전자 주식회사 Air Conditioner and Controlling method for the same
KR20140123821A (en) * 2013-04-15 2014-10-23 엘지전자 주식회사 Air Conditioner and Controlling method for the same
US9944151B2 (en) 2013-05-20 2018-04-17 Sanden Holdings Corporation Vehicle air conditioner
WO2014188984A1 (en) * 2013-05-20 2014-11-27 サンデン株式会社 Vehicle air conditioner
JP2014226979A (en) * 2013-05-20 2014-12-08 サンデン株式会社 Vehicle air conditioner
US10443886B2 (en) 2013-06-25 2019-10-15 Mitsubishi Electric Corporation Air-conditioning apparatus having an indication apparatus
WO2014208143A1 (en) * 2013-06-25 2014-12-31 三菱電機株式会社 Air conditioning device
AU2017201891B2 (en) * 2013-06-25 2018-01-18 Mitsubishi Electric Corporation Air-conditioning apparatus
CN104251518A (en) * 2013-06-25 2014-12-31 三菱电机株式会社 Air conditioning device
JP2015007502A (en) * 2013-06-25 2015-01-15 三菱電機株式会社 Air conditioner
AU2017201891C1 (en) * 2013-06-25 2019-08-29 Mitsubishi Electric Corporation Air-conditioning apparatus
JP2015068614A (en) * 2013-09-30 2015-04-13 ダイキン工業株式会社 Refrigeration unit
JP2015087020A (en) * 2013-10-28 2015-05-07 三菱電機株式会社 Refrigeration cycle device
JP2015127637A (en) * 2015-04-09 2015-07-09 三菱電機株式会社 Air conditioning device
JPWO2016166845A1 (en) * 2015-04-15 2017-12-14 三菱電機株式会社 Refrigeration cycle equipment
JP2016148510A (en) * 2016-04-07 2016-08-18 三菱電機株式会社 Air conditioner
JP2018021730A (en) * 2016-08-05 2018-02-08 日立ジョンソンコントロールズ空調株式会社 Refrigeration cycle device
JP7478967B2 (en) 2020-02-25 2024-05-08 パナソニックＩｐマネジメント株式会社 Air Conditioning Equipment
JP7450745B2 (en) 2020-03-06 2024-03-15 ダイキン工業株式会社 Heat pump systems and methods for controlling heat pump systems
US11945283B2 (en) 2022-04-15 2024-04-02 Hyundai Motor Company Thermal management system of gas injection type for vehicle

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