JPH07324833A - Refrigeration cycle and control method thereof - Google Patents

Abstract

PURPOSE:To provide a refrigeration cycle wherein, in a case where a non- azeotropic refrigerant mixture is filled in the refrigeration cycle, changes in the composition of the refrigerant circulating in the refrigeration cycle are suppressed, the operating range of the refrigeration cycle is enlarged and the amount of the refrigerant filled therein can be reduced. CONSTITUTION:In a refrigeration cycle which consists of a compressor 1, an indoor heat exchanger 3, a first pressure reducing device 4, a second pressure reducing device 6 and an outdoor heat exchanger 7 interconnected successively by pipes and which has filled therein a non-azeotropic refrigerant, mixture comprising at least two kinds of the refrigerants of different boiling points and a liquid receiver 5 disposed between the indoor heat exchanger 3 and the outdoor heat exchanger 7, the pipe connected to the liquid receiver 5 is provided with a gas-liquid mixing device 10 at its outlet end in the flowing direction of cooling fluid, whereby the cooling liquid at the inlet end of the liquid receiver 5 is brought into a gas-liquid mixed state or the interior of the liquid receiver 5 is given a pressure between the high and low pressure sides of the refrigeration cycle.

Description

【発明の詳細な説明】Detailed Description of the Invention

【０００１】[0001]

【産業上の利用分野】本発明は、冷凍サイクルとその制
御方法に係り、特に冷凍サイクル内に非共沸混合冷媒を
封入した場合の冷凍サイクル内を循環する冷媒組成の変
化を抑制し、かつ冷媒量の低減に好適な冷凍サイクルと
その制御方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerating cycle and its control method, and more particularly to suppressing a change in the composition of the refrigerant circulating in the refrigerating cycle when a non-azeotropic mixed refrigerant is enclosed in the refrigerating cycle, and The present invention relates to a refrigeration cycle suitable for reducing the amount of refrigerant and its control method.

【０００２】[0002]

【従来の技術】従来、非共沸混合冷媒を用いた冷凍サイ
クルの制御技術としては、冷凍サイクルを循環する混合
冷媒の組成比を調整し、冷凍サイクルの容量制御を行う
技術が種々提案されている。2. Description of the Related Art Conventionally, as a refrigeration cycle control technique using a non-azeotropic mixed refrigerant, various techniques have been proposed for adjusting the composition ratio of the mixed refrigerant circulating in the refrigeration cycle to control the capacity of the refrigeration cycle. There is.

【０００３】例えば、特開昭６１−９９０６６号公報に
記載の熱ポンプ装置によれば、非共沸混合冷媒を冷媒精
留塔へ導入する位置をその塔頂部または塔底部に切り替
え可能に設けた三方弁を経て冷媒精留塔に導入させるこ
とにより、主回路を流れる冷媒の組成を大きく変化させ
ることが可能となり、常に負荷に応じた好適な冷媒組成
を得ることができる。For example, according to the heat pump device disclosed in Japanese Patent Laid-Open No. 61-99066, the position at which the non-azeotropic mixed refrigerant is introduced into the refrigerant rectification column is switchably provided at the column top or column bottom. By introducing the refrigerant through the three-way valve into the refrigerant rectification column, the composition of the refrigerant flowing through the main circuit can be greatly changed, and a suitable refrigerant composition according to the load can always be obtained.

【０００４】また、特開平１−５８９６４号公報に記載
のヒートポンプシステムによれば、室内熱交換器と室外
熱交換器の間に気液分離器を設け、吸入ガス管と熱交換
可能に設けた冷媒タンクを第１接続管で気液分離器の上
部に接続するとともに、冷媒タンクを開閉弁の介設され
た第２接続管で気液分離器の下部に接続して非共沸混合
冷媒サイクルを構成することによって、冷房運転時に前
記気液分離器の上部から流出する低沸点冷媒に富んだガ
ス冷媒が冷媒タンクに流入し、前記冷媒タンク内で凝縮
し、液冷媒として貯留することにより、冷凍サイクル内
を循環する混合冷媒の組成を高沸点冷媒が多い状態とす
ることが可能となる。Further, according to the heat pump system described in JP-A-1-58964, a gas-liquid separator is provided between the indoor heat exchanger and the outdoor heat exchanger so that heat can be exchanged with the suction gas pipe. The refrigerant tank is connected to the upper part of the gas-liquid separator with the first connecting pipe, and the refrigerant tank is connected to the lower part of the gas-liquid separator with the second connecting pipe provided with the on-off valve to form a non-azeotropic mixed refrigerant cycle. By configuring, the gas refrigerant rich in low boiling point refrigerant flowing out from the upper part of the gas-liquid separator during cooling operation flows into the refrigerant tank, is condensed in the refrigerant tank, and is stored as a liquid refrigerant, It is possible to make the composition of the mixed refrigerant circulating in the refrigeration cycle in a state in which the high-boiling-point refrigerant is large.

【０００５】一方、冷凍サイクルのメンテナンス性を向
上させるため、接続配管の最大延長分の冷媒を冷凍サイ
クル内に初期封入する冷凍サイクルシステムがある。こ
の冷凍サイクルシステムでは、接続配管が短い場合、余
剰冷媒が発生し、前記余剰冷媒を貯留するタンクを必要
とする。従来の冷凍サイクルでは、この余剰冷媒の貯留
方法として二つの方法がある。その一つの方法は、凝縮
器として作用している熱交換器の後方側の高圧部に受液
器を設け、前記受液器内に余剰冷媒を貯留する方法であ
る。他の一つの方法は、平成５年度日本冷凍協会学術講
演会講演論文集ｐ４１に記載されている方法で、冷凍サ
イクルの吸入部に配設されるアキュムレータ内に余剰冷
媒を貯留する方法である。On the other hand, in order to improve the maintainability of the refrigeration cycle, there is a refrigeration cycle system in which a refrigerant for the maximum extension of the connecting pipe is initially enclosed in the refrigeration cycle. In this refrigeration cycle system, when the connecting pipe is short, surplus refrigerant is generated, and a tank for storing the surplus refrigerant is required. In the conventional refrigeration cycle, there are two methods for storing this excess refrigerant. One of the methods is a method in which a liquid receiver is provided in the high pressure portion on the rear side of the heat exchanger acting as a condenser, and excess refrigerant is stored in the liquid receiver. Another method is a method described in the 1993 academic conference of the Japan Refrigeration Association p41, which is a method of storing excess refrigerant in an accumulator arranged in the suction part of the refrigeration cycle.

【０００６】次に、前述のごとき余剰冷媒を貯留する冷
凍サイクルに非共沸混合冷媒を封入した場合について説
明する。受液器内に余剰冷媒を貯留する場合は、凝縮器
から流出される高圧の冷媒が受液器内に流入し、余剰冷
媒として貯留される。受液器内に流入する冷媒は、乾き
度が非常に小さい冷媒であるため、封入組成に近い組成
として貯留され、冷凍サイクルを循環する混合冷媒の組
成は封入組成に近い組成となる。一方、アキュムレータ
内に余剰冷媒を貯留する場合は、蒸発器から流出される
低圧の冷媒がアキュムレータ内に流入し、余剰冷媒とし
て貯留される。アキュムレータ内に流入する冷媒は、乾
き度が非常に大きい冷媒であるため、封入組成に対して
高沸点冷媒が多い組成として貯留され、冷凍サイクルを
循環する混合冷媒の組成は封入組成よりも低沸点冷媒が
多い組成となる。Next, the case where the non-azeotropic mixed refrigerant is enclosed in the refrigeration cycle for storing the excess refrigerant as described above will be described. When the excess refrigerant is stored in the liquid receiver, the high-pressure refrigerant flowing out from the condenser flows into the liquid receiver and is stored as the excess refrigerant. Since the refrigerant flowing into the liquid receiver has a very low degree of dryness, it is stored as a composition close to the sealed composition, and the composition of the mixed refrigerant circulating in the refrigeration cycle becomes a composition close to the sealed composition. On the other hand, when the excess refrigerant is stored in the accumulator, the low-pressure refrigerant flowing out from the evaporator flows into the accumulator and is stored as the excess refrigerant. The refrigerant flowing into the accumulator is a refrigerant with a very high degree of dryness, so it is stored as a composition with a high boiling point refrigerant relative to the enclosed composition, and the composition of the mixed refrigerant circulating in the refrigeration cycle has a lower boiling point than the enclosed composition. The composition has many refrigerants.

【０００７】[0007]

【発明が解決しようとする課題】ところが、前述のごと
き混合冷媒を封入した冷凍サイクルの循環冷媒組成を可
変する方法や、混合冷媒を封入した冷凍サイクルの余剰
冷媒を貯留する方法では、室内ユニットと室外ユニット
を接続する配管の長さが変化する場合や、地球環境保護
の面に対して考慮がなされていないため、次のような問
題を有する。However, in the method of varying the circulating refrigerant composition of the refrigerating cycle in which the mixed refrigerant is enclosed as described above and the method of storing the excess refrigerant in the refrigerating cycle in which the mixed refrigerant is enclosed, the indoor unit and When the length of the pipe connecting the outdoor unit changes, and because no consideration is given to the protection of the global environment, there are the following problems.

【０００８】すなわち、精留塔を用いて冷凍サイクルの
循環冷媒組成を自由に可変できるシステムにおいて、接
続配管が長い場合等で余剰冷媒がなくなる場合は、組成
を可変するために冷媒を貯めるタンク内に冷媒を貯留で
きなくなり、混合冷媒の循環冷媒組成を可変することが
できなくなる問題が生じる。また、タンク内へ冷媒を貯
めて循環冷媒組成を可変させても、冷凍サイクル内の有
効冷媒量が減少し、冷凍サイクルの効率を低下させる問
題が生じる。さらに、冷凍サイクル内の有効冷媒量を適
正にするために冷媒量を増やした場合には、地球温暖化
現象が大きくなる等の問題が生じる。That is, in a system in which the composition of the circulating refrigerant in the refrigeration cycle can be freely changed by using a rectification tower, when there is no excess refrigerant due to a long connecting pipe, etc., in a tank for storing the refrigerant to change the composition. However, there is a problem that the refrigerant cannot be stored in the tank and the circulating refrigerant composition of the mixed refrigerant cannot be changed. Further, even if the refrigerant is stored in the tank and the composition of the circulating refrigerant is varied, the amount of the effective refrigerant in the refrigeration cycle is reduced, and the efficiency of the refrigeration cycle is reduced. Further, when the amount of the refrigerant is increased in order to make the amount of the effective refrigerant in the refrigeration cycle appropriate, there arises a problem that the global warming phenomenon becomes large.

【０００９】また、気液分離器により冷凍サイクルの循
環冷媒組成を可変させる方法では、冷房運転時は循環冷
媒組成を高沸点冷媒が多くなる状態にできるが、暖房運
転時は冷媒タンク内の液冷媒が蒸発し、気液分離器内に
流入するため、循環冷媒組成は低沸点冷媒が多い状態と
なり、運転モードが異なると循環冷媒組成が変化し、圧
縮機が一定速モータを搭載している場合は、暖房時と冷
房時との間で能力が大きく異なったり、運転圧力が冷凍
サイクルの耐圧限界以上となる問題が生じる。Further, in the method of varying the circulating refrigerant composition of the refrigeration cycle by the gas-liquid separator, the circulating refrigerant composition can be in a state in which the amount of high boiling point refrigerant is large during the cooling operation, but the liquid in the refrigerant tank is heated during the heating operation. Since the refrigerant evaporates and flows into the gas-liquid separator, the circulating refrigerant composition has a large amount of low boiling point refrigerant, and the circulating refrigerant composition changes when the operation mode is different, and the compressor has a constant speed motor. In this case, there arises a problem that the capacity is greatly different between the time of heating and the time of cooling, or the operating pressure exceeds the pressure limit of the refrigeration cycle.

【００１０】また、余剰冷媒を貯留する二つの方法に
は、次のような問題がある。Further, the two methods of storing the excess refrigerant have the following problems.

【００１１】すなわち、凝縮器出口に設けた受液器によ
り余剰冷媒を貯留する方法では、高圧の液冷媒を貯留す
るため、循環冷媒組成の変化はほとんどないが、受液器
の入口および出口の配管が満液状態となるため、冷凍サ
イクルに必要な冷媒量が多くなり、地球温暖化現象を大
きくする問題が生じる。また、アキュムレータにより余
剰冷媒を貯留する方法では、低圧の乾き度の大きい冷媒
がアキュムレータに流入し、気液分離した高沸点冷媒に
富んだ液冷媒がアキュムレータに貯留されるため、循環
冷媒組成は低沸点冷媒が多くなり、冷凍サイクルの運転
圧力を上昇させ、運転限界が冷凍サイクルの耐圧限界以
上となる問題が生じる。That is, in the method of storing the excess refrigerant by the liquid receiver provided at the outlet of the condenser, since the high-pressure liquid refrigerant is stored, there is almost no change in the composition of the circulating refrigerant, but the inlet and outlet of the liquid receiver are not changed. Since the pipe is filled with liquid, the amount of refrigerant required for the refrigeration cycle increases, which causes a problem of increasing the global warming phenomenon. Further, in the method of storing the excess refrigerant by the accumulator, a low-pressure dryness-rich refrigerant flows into the accumulator, and the liquid refrigerant rich in the high-boiling-point gas-liquid separated refrigerant is stored in the accumulator, so that the circulating refrigerant composition is low. There is a problem that the amount of the boiling point refrigerant increases, the operating pressure of the refrigeration cycle rises, and the operating limit exceeds the pressure limit of the refrigeration cycle.

【００１２】本発明の目的は、前記従来技術の問題を解
決し、冷凍サイクルを流れる混合冷媒の組成の変化を抑
制することができ、かつ冷凍サイクルの運転限界を拡大
することがことができ、しかも接続配管が長くなるよう
な場合でも、必要冷媒量を少なくすることができる冷凍
サイクルを提供することにある。The object of the present invention is to solve the above-mentioned problems of the prior art, to suppress the change in the composition of the mixed refrigerant flowing through the refrigeration cycle, and to expand the operation limit of the refrigeration cycle. Moreover, it is an object of the present invention to provide a refrigeration cycle that can reduce the amount of required refrigerant even when the connection pipe becomes long.

【００１３】本発明の他の目的は、余剰冷媒を凝縮器出
口の冷媒乾き度が非常に小さい液冷媒の状態でより良く
貯留することが可能な冷凍サイクルを提供することにあ
る。Another object of the present invention is to provide a refrigeration cycle capable of better storing excess refrigerant in the state of a liquid refrigerant having a very small refrigerant dryness at the condenser outlet.

【００１４】本発明のさらに他の目的は、冷凍サイクル
の運転領域を拡大するとともに、最適運転を可能とし、
また冷凍サイクルの運転モードを空調場に最適でかつユ
ーザの所望する運転を実行し得る冷凍サイクルの制御方
法を提供することにある。Still another object of the present invention is to expand the operation range of the refrigeration cycle and enable optimum operation,
It is another object of the present invention to provide a refrigerating cycle control method in which the refrigerating cycle operation mode is optimal for an air-conditioned area and the operation desired by the user can be executed.

【００１５】[0015]

【課題を解決するための手段】前記目的は、室内熱交換
器と室外熱交換器の間に受液器を設け、この受液器に付
設する配管内を流れる冷却流体の流れ方向流出側に、ガ
スと液を混合する気液混合装置を設け、前記受液器の入
口側の冷却流体がガスと液の混合状態となるか、もしく
は前記受液器内の圧力が前記冷凍サイクルの高圧側圧力
と低圧側圧力の間の圧力としたことにより、達成され
る。The above-mentioned object is to provide a liquid receiver between the indoor heat exchanger and the outdoor heat exchanger, and to the outflow side in the flow direction of the cooling fluid flowing in the pipe attached to this liquid receiver. A gas-liquid mixing device for mixing gas and liquid is provided, and the cooling fluid at the inlet side of the receiver is in a mixed state of gas and liquid, or the pressure inside the receiver is on the high pressure side of the refrigeration cycle. This is achieved by setting the pressure between the pressure and the low-pressure side pressure.

【００１６】また、前記目的は前記受液器を前記冷凍サ
イクルの中間圧部に配設し、前記受液器から流入あるい
は流出する冷却流体がガスと液の混合状態となるよう
に、気液混合装置を配設したことによっても、達成され
る。[0016] Further, the purpose is to arrange the receiver in an intermediate pressure portion of the refrigeration cycle so that the cooling fluid flowing in or out of the receiver is in a mixed state of gas and liquid. It is also achieved by providing a mixing device.

【００１７】また、前記目的は前記気液混合装置とし
て、前記受液器の塔頂部より受液器内のガスを抽出する
ガス管と、前記受液器内の液を抽出する液管と、この液
管に設けられた減圧手段とを有して構成したものを用い
たことにより、さらには前記気液混合装置として、前記
受液器内からガスを抽出する口と、前記受液器内から液
を抽出する口と、前記抽出されたガスと液とを混合させ
て導出する冷媒導出管とを設けて構成したものを用いた
ことにより、さらには受液器の前後に設けられている第
１，第２の減圧装置の少なくとも一方を電子膨張弁とす
ることにより、より良く達成される。Further, the object is, as the gas-liquid mixing device, a gas pipe for extracting a gas in the liquid receiver from the top of the liquid receiver, and a liquid pipe for extracting the liquid in the liquid receiver. By using the one having a decompression means provided in the liquid pipe, further, as the gas-liquid mixing device, a port for extracting a gas from the inside of the liquid receiver, and an inside of the liquid receiver Further, it is provided before and after the liquid receiver by using the one configured to have a port for extracting the liquid from and a refrigerant outlet pipe for mixing and extracting the extracted gas and liquid. This is better achieved by using at least one of the first and second pressure reducing devices as an electronic expansion valve.

【００１８】さらに、前記目的は少なくとも圧縮機，四
方弁，室内熱交換器，第１減圧装置，受液器，第２減圧
装置，室外熱交換器を順次配管により接続して成る冷凍
サイクルに、沸点の異なる少なくとも二種類の冷媒を混
合して成る非共沸混合冷媒を封入し、前記第１減圧装置
または第２減圧装置により冷凍サイクルを制御する冷凍
サイクルの制御方法において、前記冷凍サイクルを流れ
る冷媒の流れ方向に対して、第１，第２減圧装置のうち
の受液器の前方に位置する減圧装置により、室内，室外
熱交換器のうちの凝縮器として作用している熱交換器の
冷媒液過冷却度または受液器内の圧力を制御し、受液器
の後方に位置する減圧装置により、吐出ガス過熱度また
は吸入ガス過熱度を制御することにより、達成される。Further, the above object is to provide a refrigeration cycle in which at least a compressor, a four-way valve, an indoor heat exchanger, a first pressure reducing device, a liquid receiver, a second pressure reducing device, and an outdoor heat exchanger are connected in sequence by piping. In a refrigerating cycle control method, in which a non-azeotropic mixed refrigerant formed by mixing at least two kinds of refrigerants having different boiling points is enclosed, and the refrigerating cycle is controlled by the first pressure reducing device or the second pressure reducing device, the refrigerating cycle flows. With respect to the flow direction of the refrigerant, the pressure reducing device located in front of the liquid receiver of the first and second pressure reducing devices causes the heat exchanger of the heat exchanger acting as the condenser of the indoor and outdoor heat exchangers to operate. This is achieved by controlling the degree of supercooling of the refrigerant liquid or the pressure in the receiver, and controlling the discharge gas superheat or the suction gas superheat by a decompression device located behind the receiver.

【００１９】[0019]

【作用】本発明では、室内熱交換器と室外熱交換器の間
に受液器を設け、この受液器に付設する配管の冷却流体
の流れ方向に対して流出側に、気液混合装置を設けてい
る。そして、前記受液器の入口側の冷却流体がガスと液
の混合状態となるか、もしくは前記受液器内の圧力が前
記冷凍サイクルの高圧側圧力と低圧側圧力の間の圧力と
した。そこで、余剰冷媒が発生すると、気液混合装置に
より受液器に流入する冷媒の乾き度もしくは湿り液と同
じ状態かまたは乾いている状態の冷媒が受液器内から流
出するため、余剰冷媒が受液器内に貯留される。つま
り、封入冷媒組成に近い液冷媒が貯留されるため、冷凍
サイクルを循環する冷媒組成と封入冷媒組成との差が小
さくなり、冷媒組成の変化を抑制することができ、その
結果冷凍サイクルの運転圧力の上昇を抑制し、運転限界
を拡大することができる。また、受液器の前後の配管内
を流れる冷媒の状態が気液二相状態となるため、配管内
に占める冷媒の質量が低減され、したがって冷凍サイク
ル全体の冷媒量を低減することができるため、接続配管
が長くなる場合でも必要な冷媒量を少なくすることがで
き、ひいては運転効率の向上を図ることが可能となる。According to the present invention, a liquid receiver is provided between the indoor heat exchanger and the outdoor heat exchanger, and a gas-liquid mixing device is provided on the outflow side of the pipe attached to the liquid receiver in the flow direction of the cooling fluid. Is provided. Then, the cooling fluid on the inlet side of the liquid receiver is in a mixed state of gas and liquid, or the pressure in the liquid receiver is set between the high pressure side pressure and the low pressure side pressure of the refrigeration cycle. Therefore, when the excess refrigerant is generated, the dryness of the refrigerant flowing into the receiver by the gas-liquid mixing device or the same state as the wet liquid or the refrigerant in the dry state flows out from the inside of the receiver. Stored in the receiver. That is, since the liquid refrigerant close to the enclosed refrigerant composition is stored, the difference between the refrigerant composition circulating in the refrigeration cycle and the enclosed refrigerant composition can be reduced, and the change in the refrigerant composition can be suppressed, resulting in the operation of the refrigeration cycle. It is possible to suppress an increase in pressure and expand the operating limit. Further, since the state of the refrigerant flowing in the pipes before and after the liquid receiver becomes the gas-liquid two-phase state, the mass of the refrigerant occupying the pipe is reduced, and therefore the amount of refrigerant in the entire refrigeration cycle can be reduced. Even when the connecting pipe becomes long, the required amount of refrigerant can be reduced, and in turn, the operating efficiency can be improved.

【００２０】また、本発明では前記受液器を冷凍サイク
ルの中間圧部に配設している。さらに、前記受液器から
流入または流出する冷却流体がガスと液の混合状態とな
るように、気液混合装置を配設している。その結果、こ
の発明においても、余剰冷媒を凝縮器出口の冷媒乾き度
が非常に小さい液冷媒として貯留することができるた
め、封入組成に近い組成の液冷媒が貯留されるので、冷
凍サイクルを循環する冷媒組成と封入冷媒組成との差が
小さくなり、冷媒組成の変化を抑制することができ、こ
れにより冷凍サイクルの運転圧力の上昇を抑制し、運転
限界を拡大することができる。また、受液器の前後の配
管内を流れる冷媒の状態が気液二相状態となるため、配
管内に占める冷媒の質量が低減され、したがって冷凍サ
イクル全体の冷媒量を低減することができるため、接続
配管が長くなる場合でも必要な冷媒量を少なくすること
ができ、これにより運転効率の向上を図ることが可能と
なる。Further, in the present invention, the liquid receiver is arranged in the intermediate pressure portion of the refrigeration cycle. Further, the gas-liquid mixing device is arranged so that the cooling fluid flowing in or out of the liquid receiver is in a mixed state of gas and liquid. As a result, also in the present invention, since the excess refrigerant can be stored as a liquid refrigerant having a very low refrigerant dryness at the condenser outlet, a liquid refrigerant having a composition close to the enclosed composition is stored, so that the refrigeration cycle is circulated. The difference between the refrigerant composition and the enclosed refrigerant composition becomes small, and the change in the refrigerant composition can be suppressed, whereby the increase in operating pressure of the refrigeration cycle can be suppressed and the operating limit can be expanded. Further, since the state of the refrigerant flowing in the pipes before and after the liquid receiver becomes the gas-liquid two-phase state, the mass of the refrigerant occupying the pipe is reduced, and therefore the amount of refrigerant in the entire refrigeration cycle can be reduced. Even when the connecting pipe becomes long, the required amount of the refrigerant can be reduced, and thus the operation efficiency can be improved.

【００２１】また、本発明では前記気液混合装置とし
て、受液器の塔頂部より受液器内のガスを抽出するガス
管と、受液器内の液を抽出する液管と、この液管に設け
られた減圧手段とを有するものを用いている。そして、
前記受液器内には気液二相状態の冷媒が流入する。一
方、気液混合装置のガス管を通じて受液器の塔頂部内の
ガス冷媒が流出し、液管を通じて受液器内の液冷媒が流
出し、これらガス冷媒と液冷媒とが混合される。このと
き、減圧手段により受液器内に流入する気液二相状態の
冷媒に対して、冷媒の乾き度もしくは湿り度が同じ状態
かまたは乾いている状態となるように調整される。した
がって、冷凍サイクル内に余剰冷媒が発生する場合は、
受液器内に封入組成に近い組成の液冷媒が貯留される
し、受液器から気液混合装置を通じて常に気液二相状態
の冷媒を導出することができる。In the present invention, as the gas-liquid mixing device, a gas pipe for extracting the gas in the receiver from the top of the receiver, a liquid pipe for extracting the liquid in the receiver, and this liquid A pipe having a pressure reducing means provided on the pipe is used. And
A refrigerant in a gas-liquid two-phase state flows into the liquid receiver. On the other hand, the gas refrigerant in the tower top of the liquid receiver flows out through the gas pipe of the gas-liquid mixing device, the liquid refrigerant in the liquid receiver flows out through the liquid pipe, and these gas refrigerant and liquid refrigerant are mixed. At this time, the decompression means adjusts the refrigerant in the gas-liquid two-phase state flowing into the liquid receiver so that the degree of dryness or the degree of wetness of the refrigerant is the same or the state is dry. Therefore, if excess refrigerant is generated in the refrigeration cycle,
A liquid refrigerant having a composition close to the sealed composition is stored in the liquid receiver, and the refrigerant in the gas-liquid two-phase state can be always drawn from the liquid receiver through the gas-liquid mixing device.

【００２２】また、本発明では前記気液混合装置とし
て、受液器内からガスを抽出する口と、受液器内から液
を抽出する口と、前記抽出されたガスと液とを混合させ
て導出する冷媒導出管とを設けて構成したものを用いて
いる。その結果、この発明においても、受液器内に封入
組成に近い組成の液冷媒が貯留されるし、受液器から気
液混合装置を通じて常に気液二相状態の冷媒を導出する
ことができる。Further, in the present invention, the gas-liquid mixing device includes a port for extracting gas from the inside of the receiver, a port for extracting liquid from inside of the receiver, and a mixture of the extracted gas and liquid. It is configured by providing a refrigerant outlet pipe for leading out by means of. As a result, also in the present invention, the liquid refrigerant having a composition close to the enclosed composition is stored in the receiver, and the refrigerant in the gas-liquid two-phase state can always be drawn from the receiver through the gas-liquid mixing device. .

【００２３】また、本発明では前記第１，第２減圧装置
の少なくとも一方に、電子膨張弁を用いている。これに
より、冷凍サイクル内を的確に適応制御することができ
る。Further, in the present invention, an electronic expansion valve is used for at least one of the first and second pressure reducing devices. As a result, the inside of the refrigeration cycle can be appropriately adaptively controlled.

【００２４】さらに、本発明では冷凍サイクルを流れる
冷媒の流れ方向に対して、冷凍サイクルを制御する第
１，第２減圧装置のうちの受液器の前方に位置する減圧
装置により、室内，室外熱交換器のうちの凝縮器として
作用している熱交換器の冷媒液過冷却度または受液器内
の圧力を制御するようにしている。また、前記冷媒の流
れ方向に対して、第１，第２減圧装置のうちの受液器の
後方に位置する減圧装置により、吐出ガス過熱度または
吸入ガス過熱度を制御するようにしている。このよう
に、冷凍サイクルを流れる冷媒の流れ方向に対して、受
液器の前方に位置する減圧装置により凝縮器の冷媒液過
冷却度または受液器内の圧力を制御し、受液器の後方に
位置する減圧装置により吐出ガス過熱度または吸入ガス
過熱度を制御するようにしているため、空気条件が高い
場合には、受液器の前方に位置する減圧装置を制御する
ことによって吐出圧力の上昇を抑えることができ、さら
に受液器の後方に位置する減圧装置を制御することによ
って圧縮機への液戻り量を最適に制御できるので、冷凍
サイクルの運転領域の拡大を図ることができ、かつ最適
運転が可能となる。また、凝縮器出口冷媒液過冷却度の
設定値または受液器内の圧力の設定値を変更することに
より、冷凍サイクルの運転モードを省エネルギー重視タ
イプや能力重視タイプとすることができるため、これら
の運転モードを選択することにより、空調場に最適でか
つユーザの所望する運転を行うことができる。Further, according to the present invention, the decompression device located in front of the liquid receiver among the first and second decompression devices for controlling the refrigeration cycle with respect to the flow direction of the refrigerant flowing through the refrigeration cycle can be used indoors or outdoors. The refrigerant liquid supercooling degree of the heat exchanger acting as the condenser of the heat exchanger or the pressure in the liquid receiver is controlled. Further, the discharge gas superheat degree or the suction gas superheat degree is controlled by the pressure reducing device of the first and second pressure reducing devices located behind the liquid receiver in the flow direction of the refrigerant. Thus, with respect to the flow direction of the refrigerant flowing through the refrigeration cycle, the refrigerant liquid supercooling degree of the condenser or the pressure in the receiver is controlled by the pressure reducing device located in front of the receiver, Since the discharge gas superheat degree or the suction gas superheat degree is controlled by the pressure reducer located at the rear, the discharge pressure can be controlled by controlling the pressure reducer located in front of the receiver when the air condition is high. The amount of liquid returned to the compressor can be optimally controlled by controlling the pressure reducing device located behind the liquid receiver, so that the operating range of the refrigeration cycle can be expanded. In addition, optimum operation becomes possible. Further, by changing the set value of the condenser outlet refrigerant liquid subcooling degree or the set value of the pressure in the receiver, the operation mode of the refrigeration cycle can be set to the energy-saving type or the capacity-oriented type. By selecting the operation mode of, it is possible to perform the operation most suitable for the air-conditioning area and desired by the user.

【００２５】[0025]

【実施例】以下、本発明の実施例を図面により説明す
る。Embodiments of the present invention will be described below with reference to the drawings.

【００２６】図１は本発明冷凍サイクルの一実施例を示
す系統図である。FIG. 1 is a system diagram showing an embodiment of the refrigeration cycle of the present invention.

【００２７】この図１に示す実施例の冷凍サイクルは、
圧縮機１と、四方弁２と、室内熱交換器３と、第１減圧
装置４と、受液器５と、第２減圧装置６と、室外熱交換
器７とがガス接続配管９ａや液接続配管９ｂを介して順
次接続され、閉ループに構成されている。The refrigeration cycle of the embodiment shown in FIG.
The compressor 1, the four-way valve 2, the indoor heat exchanger 3, the first pressure reducing device 4, the liquid receiver 5, the second pressure reducing device 6, and the outdoor heat exchanger 7 are connected to the gas connecting pipe 9a or the liquid. They are sequentially connected via the connection pipe 9b and are configured as a closed loop.

【００２８】前記圧縮機１には、液冷媒の戻り量を調整
するアキュムレータ８が接続されている。前記受液器５
は、室内熱交換器３側に付設された第１減圧装置４と、
室外熱交換器７側に付設された第２減圧装置６との間に
設けられており、冷凍サイクルの配管内で発生した余剰
冷媒を貯留するようになっている。前記受液器５には、
気液混合装置１０が設けられている。この気液混合装置
１０は、液冷媒とガス冷媒とをある一定の乾き度もしく
は湿り度に調整可能に構成されている。前記冷凍サイク
ル内には、少なくとも二種類の沸点の異なる冷媒が、最
大接続配管分封入され、図１に実線矢印および破線矢印
で示すように、冷凍サイクル内を流れるようになってい
る。The compressor 1 is connected to an accumulator 8 for adjusting the amount of liquid refrigerant returned. The liquid receiver 5
Is a first pressure reducing device 4 attached to the indoor heat exchanger 3 side,
It is provided between the outdoor heat exchanger 7 and the second pressure reducing device 6 attached to the side thereof, and stores the excess refrigerant generated in the piping of the refrigeration cycle. In the liquid receiver 5,
A gas-liquid mixing device 10 is provided. The gas-liquid mixing device 10 is configured so that the liquid refrigerant and the gas refrigerant can be adjusted to have a certain dryness or wetness. In the refrigeration cycle, at least two kinds of refrigerants having different boiling points are enclosed in the maximum connection pipe and flow in the refrigeration cycle as shown by solid arrows and broken arrows in FIG.

【００２９】さらに、前記冷凍サイクルにはこれの制御
系統が連結されているが、その制御系統については後に
詳述する。Further, a control system for the refrigeration cycle is connected to the refrigeration cycle, which will be described in detail later.

【００３０】次に、前記冷凍サイクルにおける暖房運転
時および冷房運転時の作用について説明する。Next, the operation during the heating operation and the cooling operation in the refrigeration cycle will be described.

【００３１】（１）冷房運転時 四方弁２を実線表示のごとく切り替えることにより、冷
媒は実線矢印のように、圧縮機１−四方弁２−室外熱交
換器７−第２減圧装置６−受液器５−第１減圧装置４−
室内熱交換器３−四方弁２−アキュムレータ８と流れ
る。圧縮機１で高温高圧のガス冷媒に圧縮された混合冷
媒は、室外熱交換器７で前記室外熱交換器７を循環する
空気に放熱し、凝縮して液冷媒となる。前記室外熱交換
器７で凝縮した液冷媒は、第２減圧装置６により減圧さ
れ、気液二相状態となり、受液器５内に導かれる。つい
で、気液混合装置１０により受液器５に流入する冷媒の
乾き度もしくは湿り度と同じ状態かまたは乾いている状
態で受液器５内から流出し、液接続配管９ｂに導かれ
る。液接続配管９ｂに導かれた冷媒は、第１減圧装置４
で減圧され、所定の圧力となり、室内熱交換器３に流入
し、前記室内熱交換器３を循環する空気から吸熱し、蒸
発して気液二相またはガス冷媒となり、四方弁２を経て
アキュムレータ８に流入する。そして、前記アキュムレ
ータ８では圧縮機１へ戻る冷媒の乾き度もしくは湿り度
が調整され、圧縮機１に吸入される。ここで、アキュム
レータ８内の混合冷媒の状態と、受液器５内の混合冷媒
の状態について説明する。(1) During cooling operation By switching the four-way valve 2 as indicated by the solid line, the refrigerant is compressed as indicated by the solid line arrow: compressor 1-four-way valve 2-outdoor heat exchanger 7-second pressure reducing device 6-receiver. Liquid container 5-First pressure reducing device 4-
It flows with the indoor heat exchanger 3-four-way valve 2-accumulator 8. The mixed refrigerant compressed into the high-temperature and high-pressure gas refrigerant in the compressor 1 radiates heat to the air circulating in the outdoor heat exchanger 7 in the outdoor heat exchanger 7 and is condensed to become a liquid refrigerant. The liquid refrigerant condensed in the outdoor heat exchanger 7 is decompressed by the second decompression device 6, becomes a gas-liquid two-phase state, and is introduced into the liquid receiver 5. Next, the gas-liquid mixing device 10 causes the refrigerant to flow into the liquid receiver 5 to flow out from the liquid receiver 5 in the same state as the dryness or wetness or in a dry state, and is guided to the liquid connection pipe 9b. The refrigerant guided to the liquid connection pipe 9b is the first pressure reducing device 4
Is reduced to a predetermined pressure, flows into the indoor heat exchanger 3, absorbs heat from the air circulating in the indoor heat exchanger 3, evaporates to become a gas-liquid two-phase or gas refrigerant, and passes through the four-way valve 2 and an accumulator. Inflow to 8. Then, in the accumulator 8, the dryness or wetness of the refrigerant returning to the compressor 1 is adjusted, and the refrigerant is sucked into the compressor 1. Here, the state of the mixed refrigerant in the accumulator 8 and the state of the mixed refrigerant in the liquid receiver 5 will be described.

【００３２】図２はアキュムレータ内の混合冷媒の状態
を表した気液平衡線図、図３は受液器内の混合冷媒の状
態を表した気液平衡線図である。ここでは、説明の便宜
上、沸点の異なる二種類の冷媒を混合した場合について
説明する。FIG. 2 is a vapor-liquid equilibrium diagram showing the state of the mixed refrigerant in the accumulator, and FIG. 3 is a vapor-liquid equilibrium diagram showing the state of the mixed refrigerant in the receiver. Here, for convenience of description, a case where two types of refrigerants having different boiling points are mixed will be described.

【００３３】前記アキュムレータ８に流入する冷媒は、
過熱ガス冷媒または乾き度の大きい気液二相状態の冷媒
である。このアキュムレータ８内では、液冷媒とガス冷
媒が分離して共存し、その混合比は封入冷媒組成Ｘに対
して、液冷媒は高沸点冷媒が多い冷媒組成ＸＬ１とな
り、ガス冷媒は封入冷媒組成Ｘに近い冷媒組成ＸＧ１と
なる。一方、受液器５に流入する冷媒は、乾き度の小さ
い気液二相状態の冷媒である。受液器５内では、液冷媒
とガス冷媒が分離して共存し、その混合比は封入冷媒組
成Ｘに対して、ガス冷媒は低沸点冷媒が多い冷媒組成Ｘ
Ｇ２となり、液冷媒は封入冷媒組成Ｘに近い冷媒組成Ｘ
Ｌ２となる。ここで、室内ユニットと室外ユニットを結
ぶ接続配管が短い場合は余剰冷媒が発生するが、気液混
合装置１０により受液器５に流入する冷媒の乾き度もし
くは湿り度と同じ状態かまたは乾いている状態の冷媒が
受液器５内から流出するため、余剰冷媒は受液器５内に
貯留される。すなわち、受液器５内には封入冷媒組成に
近い液冷媒が貯留されるため、冷凍サイクルを循環する
冷媒組成と封入冷媒組成との差が小さくなり、冷媒組成
の変化を抑制することができる。また、液接続配管９ｂ
を流れる冷媒の状態は、気液混合装置１０により気液二
相状態となるため、液接続配管９ｂに占める冷媒の質量
が低減され、冷凍サイクル全体の冷媒量を低減すること
ができる。The refrigerant flowing into the accumulator 8 is
It is a superheated gas refrigerant or a gas-liquid two-phase refrigerant with a high degree of dryness. In the accumulator 8, the liquid refrigerant and the gas refrigerant are separated and coexist, and the mixing ratio thereof is the filled refrigerant composition X, the liquid refrigerant is the refrigerant composition XL1 having many high boiling point refrigerants, and the gas refrigerant is the enclosed refrigerant composition X. Refrigerant composition XG1 close to On the other hand, the refrigerant flowing into the liquid receiver 5 is a gas-liquid two-phase refrigerant having a low degree of dryness. In the liquid receiver 5, the liquid refrigerant and the gas refrigerant are separated and coexist, and the mixing ratio thereof is the enclosed refrigerant composition X, and the gas refrigerant is the refrigerant composition X having a large amount of low boiling point refrigerant.
G2, and the liquid refrigerant has a refrigerant composition X close to the enclosed refrigerant composition X.
It becomes L2. Here, when the connecting pipe connecting the indoor unit and the outdoor unit is short, surplus refrigerant is generated, but in the same state as the dryness or wetness of the refrigerant flowing into the liquid receiver 5 by the gas-liquid mixing device 10, or when it is dry. Since the refrigerant in the existing state flows out of the liquid receiver 5, the surplus refrigerant is stored in the liquid receiver 5. That is, since the liquid refrigerant close to the filled refrigerant composition is stored in the liquid receiver 5, the difference between the refrigerant composition circulating in the refrigeration cycle and the filled refrigerant composition becomes small, and the change in the refrigerant composition can be suppressed. . Also, the liquid connection pipe 9b
Since the state of the refrigerant flowing through is in a gas-liquid two-phase state by the gas-liquid mixing device 10, the mass of the refrigerant occupying the liquid connection pipe 9b is reduced, and the refrigerant amount of the entire refrigeration cycle can be reduced.

【００３４】（２）暖房運転時 四方弁２を破線表示のごとく切り替えることにより、冷
媒は破線矢印のように、圧縮機１−四方弁２−室内熱交
換器３−第１減圧装置４−受液器５−第２減圧装置６−
室外熱交換器７−四方弁２−アキュムレータ８と流れ
る。圧縮機１で高温高圧のガス冷媒に圧縮された混合冷
媒は、室内熱交換器３で前記室内熱交換器３を循環する
空気に放熱し、凝縮して液冷媒となる。前記室内熱交換
器３で凝縮した液冷媒は、第１減圧装置４により減圧さ
れ、気液二相状態となり、液接続配管９ｂを通り、受液
器５内に導かれる。ついで、気液混合装置１０により受
液器５に流入する冷媒の乾き度もしくは湿り度と同じ状
態かまたは乾いている状態で受液器５内から流出し、第
２減圧装置６で減圧され、所定の圧力となり、室外熱交
換器７に流入する。前記室外熱交換器７に流入した気液
二相状態の冷媒は、前記室外熱交換器７を循環する空気
から吸熱して蒸発し、四方弁２を経てアキュムレータ８
に流入する。そして、前記アキュムレータ８では圧縮機
１へ戻る冷媒の乾き度もしくは湿り度が調整され、圧縮
機１に吸入される。ここで、アキュムレータ８内の混合
冷媒の状態と、受液器５内の混合冷媒の状態は、前述し
たところと同様である。ここで、室内ユニットと室外ユ
ニットを結ぶ接続配管が短い場合は余剰冷媒が発生する
が、気液混合装置１０により受液器５に流入する冷媒の
乾き度もしくは湿り度と同じ状態かまたは乾いている状
態の冷媒が受液器５内から流出するため、余剰冷媒は受
液器５内に貯留される。すなわち、受液器５内には封入
冷媒組成に近い液冷媒が貯留されるため、冷凍サイクル
を循環する冷媒組成と封入冷媒組成との差が小さくな
り、冷媒組成の変化を抑制することができる。また、液
接続配管９ｂを流れる冷媒の状態は、第１減圧装置４に
より気液二相状態となるため、液接続配管９ｂに占める
冷媒の質量が低減され、冷凍サイクル全体の冷媒量を低
減することができる。(2) During heating operation By switching the four-way valve 2 as shown by the broken line, the refrigerant is compressed as indicated by the broken-line arrow: compressor 1-four-way valve 2-indoor heat exchanger 3-first pressure reducing device 4-receiver Liquid container 5-second pressure reducing device 6-
It flows with the outdoor heat exchanger 7-four-way valve 2-accumulator 8. The mixed refrigerant compressed into the high-temperature and high-pressure gas refrigerant in the compressor 1 radiates heat to the air circulating in the indoor heat exchanger 3 in the indoor heat exchanger 3 and is condensed to become a liquid refrigerant. The liquid refrigerant condensed in the indoor heat exchanger 3 is decompressed by the first decompression device 4, becomes a gas-liquid two-phase state, and is introduced into the liquid receiver 5 through the liquid connection pipe 9b. Then, by the gas-liquid mixing device 10, the refrigerant flows out of the liquid receiver 5 in the same state as the dryness or wetness of the refrigerant flowing into the liquid receiver 5, or in a dry state, and is decompressed by the second pressure reducing device 6, It reaches a predetermined pressure and flows into the outdoor heat exchanger 7. The gas-liquid two-phase refrigerant flowing into the outdoor heat exchanger 7 absorbs heat from the air circulating in the outdoor heat exchanger 7 and evaporates, and passes through the four-way valve 2 and the accumulator 8
Flow into. Then, in the accumulator 8, the dryness or wetness of the refrigerant returning to the compressor 1 is adjusted, and the refrigerant is sucked into the compressor 1. Here, the state of the mixed refrigerant in the accumulator 8 and the state of the mixed refrigerant in the liquid receiver 5 are the same as those described above. Here, when the connecting pipe connecting the indoor unit and the outdoor unit is short, surplus refrigerant is generated, but in the same state as the dryness or wetness of the refrigerant flowing into the liquid receiver 5 by the gas-liquid mixing device 10, or when it is dry. Since the refrigerant in the existing state flows out of the liquid receiver 5, the surplus refrigerant is stored in the liquid receiver 5. That is, since the liquid refrigerant close to the filled refrigerant composition is stored in the liquid receiver 5, the difference between the refrigerant composition circulating in the refrigeration cycle and the filled refrigerant composition becomes small, and the change in the refrigerant composition can be suppressed. . Further, the state of the refrigerant flowing through the liquid connecting pipe 9b is changed to the gas-liquid two-phase state by the first pressure reducing device 4, so the mass of the refrigerant occupying the liquid connecting pipe 9b is reduced, and the refrigerant amount of the entire refrigeration cycle is reduced. be able to.

【００３５】ここで、前記冷凍サイクルに付設される気
液混合装置の色々な実施例について、図４，図５および
図６により説明する。Here, various embodiments of the gas-liquid mixing device attached to the refrigeration cycle will be described with reference to FIGS. 4, 5 and 6.

【００３６】まず、図４に示す気液混合装置は、前記受
液器５内に冷媒液を導入または導出する冷媒液導入出管
１１ａ，１１ｂと、受液器５の塔頂部より冷媒ガスを導
出する冷媒ガス導出管１３ａ，１３ｂとが設けられてお
り、これらの管は図１に示す液接続配管９ｂに接続され
ている。前記冷媒液導入出管１１ａ，１１ｂは、その先
端が受液器５の底面部まで伸びており、冷媒ガス導出管
１３ａ，１３ｂとの接続部の前方に、減圧手段である乾
き度調整用減圧装置１２ａ，１２ｂが設けられている。First, in the gas-liquid mixing apparatus shown in FIG. 4, the refrigerant liquid introducing / extracting pipes 11a and 11b for introducing or discharging the refrigerant liquid into the liquid receiver 5 and the refrigerant gas from the tower top of the liquid receiver 5 are provided. Refrigerant gas lead-out pipes 13a and 13b for leading out are provided, and these pipes are connected to the liquid connection pipe 9b shown in FIG. The refrigerant liquid inlet / outlet pipes 11a, 11b have their tips extending to the bottom surface of the liquid receiver 5, and in front of the connecting portion with the refrigerant gas outlet pipes 13a, 13b, a decompression means for dryness adjustment. Devices 12a, 12b are provided.

【００３７】そして、この図４に示す気液混合装置では
受液器５内に導かれる気液二相状態の冷媒は、冷媒液導
入出管１１ａを通り、受液器５内に流入する。ついで、
他の冷媒液導入出管１１ｂを通り、乾き度調整用減圧装
置１２ｂにより液量が調整され、受液器５より流出す
る。一方、冷媒ガス導出管１３ｂにより受液器５内の塔
頂部にあるガス冷媒が流出し、前記冷媒液導入出管１１
ｂを流れる液冷媒と混合される。ここで、乾き度調整用
減圧装置１２ｂの減圧量は、冷媒液導入出管１１ａを流
れる気液二相状態の冷媒に対して、冷媒の乾き度もしく
は湿り度が同じ状態かまたは乾いている状態となるよう
に選定されているため、余剰冷媒が発生する場合は、受
液器５内に液冷媒を貯留することができる。In the gas-liquid mixing device shown in FIG. 4, the gas-liquid two-phase refrigerant introduced into the liquid receiver 5 flows into the liquid receiver 5 through the refrigerant liquid inlet / outlet pipe 11a. Then,
After passing through another refrigerant liquid inlet / outlet pipe 11b, the liquid amount is adjusted by the dryness adjusting pressure reducing device 12b, and the liquid flows out from the liquid receiver 5. On the other hand, the gas refrigerant at the top of the tower in the liquid receiver 5 flows out through the refrigerant gas outlet pipe 13b, and the refrigerant liquid inlet / outlet pipe 11
It is mixed with the liquid refrigerant flowing through b. Here, the decompression amount of the dryness adjusting decompression device 12b is such that the refrigerant has the same dryness or wetness with respect to the gas-liquid two-phase refrigerant flowing through the refrigerant liquid inlet / outlet pipe 11a or is in a dry state. Therefore, when excess refrigerant is generated, the liquid refrigerant can be stored in the liquid receiver 5.

【００３８】また、図５に示す気液混合装置は、先端部
を受液器５の塔頂部内に臨ませて設けられた冷媒導入出
管１５ａ，１５ｂと、一端部は当該冷媒導入出管１５
ａ，１５ｂの先端部に接続され、他端部は受液器５内の
底部に挿入された冷媒液導出管１４ａ，１４ｂとを有し
て構成されている。前記冷媒導入出管１５ａ，１５ｂ
は、図１に示す液接続配管９ｂに接続されている。Further, in the gas-liquid mixing device shown in FIG. 5, the refrigerant introducing / extracting pipes 15a and 15b are provided with the tip end thereof facing the inside of the tower of the liquid receiver 5, and one end thereof is the refrigerant introducing / extracting pipe. 15
The refrigerant liquid outlet pipes 14a and 14b are connected to the tip ends of the a and 15b, and the other end portions thereof are provided with refrigerant liquid outlet pipes 14a and 14b inserted into the bottom portion of the liquid receiver 5. The refrigerant inlet / outlet pipes 15a, 15b
Is connected to the liquid connection pipe 9b shown in FIG.

【００３９】この図５に示す気液混合装置では、冷媒導
入出管１５ａ，１５ｂのうちの一方の冷媒導入出管によ
り気液二相状態の冷媒を受液器５内に導入する。そし
て、他方の冷媒導入出管の端部開口であるガス抽出口に
より受液器５の塔頂部からガスを抽出し、また冷媒液導
出管１４ａ，１４ｂのうちの、ガス導出中の冷媒導入出
管側の冷媒液導出管の端部開口である液抽出口により受
液器５内の液を抽出し、当該冷媒導入出管内で前記ガス
と液とを混合させ、気液二相状態の冷媒として送り出す
ようになっている。In the gas-liquid mixing device shown in FIG. 5, one of the refrigerant introducing / extracting pipes 15a, 15b introduces the gas-liquid two-phase refrigerant into the liquid receiver 5. Then, the gas is extracted from the tower top of the liquid receiver 5 by the gas extraction port that is the end opening of the other refrigerant introduction / extraction pipe, and the refrigerant introduction / extraction of the refrigerant liquid outflow pipe 14a, 14b during the gas outflow. The liquid in the liquid receiver 5 is extracted by the liquid extraction port that is the end opening of the refrigerant liquid outlet pipe on the pipe side, and the gas and the liquid are mixed in the refrigerant inlet / outlet pipe, and the refrigerant in the gas-liquid two-phase state It is supposed to be sent out as.

【００４０】さらに、図６に示す気液混合装置は、受液
器５内にＵ字管１６ａ，１６ｂを挿入して構成されてい
る。各Ｕ字管１６ａ，１６ｂには、受液器５の塔頂部内
に臨む位置にガス抽出口であるガス穴１７ａ，１７ｂが
設けられ、受液器５内の底部に臨む位置に液抽出口であ
る液穴１８ａ，１８ｂが設けられている。また、各Ｕ字
管１６ａ，１６ｂにおける受液器５から突出された端部
は、図１に示す液接続配管９ｂに接続されている。Further, the gas-liquid mixing device shown in FIG. 6 is constructed by inserting U-shaped tubes 16a and 16b into the liquid receiver 5. Each of the U-shaped pipes 16a, 16b is provided with gas holes 17a, 17b, which are gas extraction ports, at positions facing the tower top of the liquid receiver 5, and liquid extraction ports at positions facing the bottom of the liquid receiver 5. Liquid holes 18a and 18b are provided. The ends of the U-shaped pipes 16a and 16b protruding from the liquid receiver 5 are connected to the liquid connection pipe 9b shown in FIG.

【００４１】而して、この図６に示す気液混合装置で
は、Ｕ字管１６ａ，１６ｂのうちの一方のＵ字管より気
液二相状態の冷媒が受液器５内に導入され、また他方の
Ｕ字管のガス穴より受液器５の塔頂部内からガスが抽出
され、当該Ｕ字管の液穴より受液器５内の底部から液が
抽出され、これらガスと液とが当該Ｕ字管内で混合さ
れ、気液二相状態の冷媒として送り出される。Thus, in the gas-liquid mixing device shown in FIG. 6, the refrigerant in the gas-liquid two-phase state is introduced into the liquid receiver 5 from one of the U-shaped tubes 16a and 16b. Gas is extracted from the tower top of the receiver 5 through the gas hole of the other U-shaped tube, and liquid is extracted from the bottom of the receiver 5 through the liquid hole of the U-shaped tube. Are mixed in the U-shaped tube and sent as a refrigerant in a gas-liquid two-phase state.

【００４２】これら図５および図６に示す実施例の気液
混合装置の他の作用については、前記図４に示す実施例
の気液混合装置と同様である。Other functions of the gas-liquid mixing apparatus of the embodiment shown in FIGS. 5 and 6 are the same as those of the gas-liquid mixing apparatus of the embodiment shown in FIG.

【００４３】次に、本発明の冷凍サイクルの運転効率に
ついて説明する。Next, the operating efficiency of the refrigeration cycle of the present invention will be described.

【００４４】図７は冷凍サイクルを流れる混合冷媒の組
成と冷凍サイクルの運転効率との関係を示した図であ
る。FIG. 7 is a diagram showing the relationship between the composition of the mixed refrigerant flowing through the refrigeration cycle and the operating efficiency of the refrigeration cycle.

【００４５】この図７において、アキュムレータ等の低
圧側に付設するタンク内に余剰冷媒を貯留した場合、余
剰冷媒として貯留される液冷媒は図２に示すごとく高沸
点冷媒が多い冷媒組成となるため、冷凍サイクルを流れ
る混合冷媒は低沸点冷媒が多い冷媒組成となり、このた
め吐出圧力の上昇を招き、冷凍サイクルの運転効率を低
下させる。一方、受液器に余剰冷媒を貯留した場合、余
剰冷媒として貯留される液冷媒は図３に示すごとく封入
冷媒組成に近いため、冷凍サイクルを流れる混合冷媒も
封入組成に近くなり、このため吐出圧力の上昇を抑え、
冷凍サイクルの運転効率の低下を抑えることが可能であ
る。In FIG. 7, when the excess refrigerant is stored in a tank attached to the low pressure side such as an accumulator, the liquid refrigerant stored as the excess refrigerant has a refrigerant composition with a large amount of high boiling point refrigerant as shown in FIG. The mixed refrigerant flowing through the refrigeration cycle has a composition with a large amount of low-boiling-point refrigerant, which increases the discharge pressure and reduces the operating efficiency of the refrigeration cycle. On the other hand, when the excess refrigerant is stored in the receiver, the liquid refrigerant stored as the excess refrigerant is close to the composition of the enclosed refrigerant as shown in FIG. 3, so that the mixed refrigerant flowing through the refrigeration cycle is also close to the composition of the enclosed refrigerant. Suppresses the rise in pressure,
It is possible to suppress a decrease in operating efficiency of the refrigeration cycle.

【００４６】以上のように構成された冷凍サイクルは、
余剰冷媒を凝縮器出口の冷媒乾き度が非常に小さい液冷
媒の状態で貯留することができるために、封入組成に近
い組成の液冷媒が貯留されるので、冷凍サイクルを流れ
る混合冷媒の変化を抑制することができ、冷凍サイクル
の運転圧力の上昇を抑制し、運転限界を拡大することが
できる。また、受液器の前後の配管内を流れる冷媒の状
態が気液二相状態であるため、液冷媒の封入量を低減す
ることができるため、接続配管が長くなる場合でも、必
要冷媒量を少なくすることができる。The refrigeration cycle configured as described above is
Since the excess refrigerant can be stored in a liquid refrigerant state in which the refrigerant dryness of the condenser outlet is very small, a liquid refrigerant having a composition close to the enclosed composition is stored, so that a change in the mixed refrigerant flowing in the refrigeration cycle is prevented. It is possible to suppress the increase of the operation pressure of the refrigeration cycle and to expand the operation limit. In addition, since the state of the refrigerant flowing in the pipes before and after the receiver is a gas-liquid two-phase state, it is possible to reduce the amount of liquid refrigerant enclosed, so even if the connection pipe becomes long, the required amount of refrigerant is Can be reduced.

【００４７】また、受液器に余剰冷媒を貯留し、冷凍サ
イクルを流れる混合冷媒の冷媒組成が封入組成に近くな
ることにより、冷凍サイクルの運転効率の低下を抑える
ことができる。Further, since the excess refrigerant is stored in the liquid receiver and the refrigerant composition of the mixed refrigerant flowing through the refrigeration cycle is close to the enclosed composition, it is possible to suppress the reduction of the operation efficiency of the refrigeration cycle.

【００４８】ここで、第１減圧装置，第２減圧装置とし
て、本実施例では電子膨張弁を用いているが、キャピラ
リチューブ，温度式膨張弁，もしくは減圧量を調整でき
る機構を備えたものであっても、また第１減圧装置と第
２減圧装置の種類が異なっている場合も、本実施例と同
様の効果がある。Here, although electronic expansion valves are used as the first pressure reducing device and the second pressure reducing device in this embodiment, they are provided with a capillary tube, a temperature type expansion valve, or a mechanism capable of adjusting the amount of pressure reduction. Even if there is, or when the types of the first pressure reducing device and the second pressure reducing device are different, the same effect as the present embodiment is obtained.

【００４９】ついで、本発明冷凍サイクルの制御方法の
一例を説明する。Next, an example of the control method of the refrigeration cycle of the present invention will be described.

【００５０】図１は冷凍サイクルとその制御系統を示
し、図８および図９は暖房運転時および冷房運転時のフ
ローチャートである。FIG. 1 shows a refrigeration cycle and its control system, and FIGS. 8 and 9 are flow charts during heating operation and cooling operation.

【００５１】まず、図１に示す第１，第２減圧装置４，
６として、この実施例では電子膨張弁を用いている。First, the first and second pressure reducing devices 4, 4 shown in FIG.
6, an electronic expansion valve is used in this embodiment.

【００５２】ところで、制御系統は図１に示すように、
マイクロコンピュータ２０と、これに接続されたメモリ
部２１と、熱交換器流入空気温度検出部２２と、吐出ガ
ス過熱度検出部２３と、暖房用凝縮器出口過冷却度検出
部２４ａと、冷房用凝縮器出口過冷却度検出部２４ｂ
と、電子膨張弁である第１，第２減圧装置４，６を各別
に駆動する膨張弁駆動回路２５ａ，２５ｂと、温度検出
器２６ａ〜２６ｅとを備えて構成されている。By the way, the control system is as shown in FIG.
Microcomputer 20, memory unit 21 connected thereto, heat exchanger inflow air temperature detecting unit 22, discharge gas superheat degree detecting unit 23, heating condenser outlet supercooling degree detecting unit 24a, and cooling unit Condenser outlet supercooling degree detection unit 24b
And expansion valve drive circuits 25a and 25b for individually driving the first and second pressure reducing devices 4 and 6 which are electronic expansion valves, and temperature detectors 26a to 26e.

【００５３】前記冷凍サイクル内には、沸点の異なる少
なくとも二種類の冷媒が混合され、封入されているが、
ここでは二種類の冷媒を混合したものを用いるものとす
る。さらに、ここでは説明の便宜上、冷凍サイクルを制
御する状態量として、凝縮器出口過冷却度と吐出ガス過
熱度を制御する場合について説明する。At least two kinds of refrigerants having different boiling points are mixed and enclosed in the refrigeration cycle.
Here, a mixture of two types of refrigerant is used. Further, here, for convenience of description, a case where the condenser outlet supercooling degree and the discharge gas superheat degree are controlled as state quantities for controlling the refrigeration cycle will be described.

【００５４】前記メモリ部２１には、冷凍サイクルの状
態量を制御するための設定値が記憶され、マイクロコン
ピュータ２０からの要求に応じてその設定値を送り込む
ようになっている。A set value for controlling the state quantity of the refrigeration cycle is stored in the memory section 21, and the set value is sent in response to a request from the microcomputer 20.

【００５５】前記熱交換器流入空気温度検出部２２は、
温度検出器２６ａ，２６ｂから室内熱交換器３および室
外熱交換器７の流入空気温度の検出値を取り込み、電気
的信号に変換し、マイクロコンピュータ２０に送り込
む。The heat exchanger inflow air temperature detecting section 22 is
The detected values of the inflow air temperature of the indoor heat exchanger 3 and the outdoor heat exchanger 7 are fetched from the temperature detectors 26a and 26b, converted into electric signals, and sent to the microcomputer 20.

【００５６】前記吐出ガス過熱度検出部２３は、温度検
出器２６ｃより圧縮機１から吐出された吐出ガス温度の
検出値を取り込み、電気的信号に変換し、マイクロコン
ピュータ２０に送り込む。The discharge gas superheat degree detection unit 23 takes in the detected value of the discharge gas temperature discharged from the compressor 1 from the temperature detector 26c, converts it into an electric signal, and sends it to the microcomputer 20.

【００５７】前記暖，冷房用凝縮器出口冷却度検出部２
４ａ，２４ｂは、当該温度検出器２６ｄ，２６ｅから凝
縮器として作用したときの室内熱交換器３および室外熱
交換器７よりその出口温度の検出値を取り込み、それぞ
れ電気的信号に変換してマイクロコンピュータ２０に送
り込む。Cooling degree detecting section 2 for the condenser for hot and cold use
4a and 24b take in the detected values of the outlet temperatures from the indoor heat exchanger 3 and the outdoor heat exchanger 7 when they act as condensers from the temperature detectors 26d and 26e, respectively, and convert them into electrical signals to generate micro signals. Send to computer 20.

【００５８】前記マイクロコンピュータ２０は、前述の
各部から検出値を取り込み、電子膨張弁である第１，第
２減圧装置４，６の開度を演算し、その演算値をそれぞ
れ膨張弁駆動回路２５ａ，２５ｂに送り込むようになっ
ている。The microcomputer 20 takes in the detected values from the above-mentioned respective parts, calculates the opening degrees of the first and second pressure reducing devices 4, 6 which are electronic expansion valves, and outputs the calculated values respectively to the expansion valve drive circuit 25a. , 25b.

【００５９】次に、暖房運転時および冷房運転時の制御
方法について説明する。Next, the control method during the heating operation and the cooling operation will be described.

【００６０】（１）暖房運転 この冷凍サイクルの暖房運転時には、図８に示すよう
に、所定の時間Δｔ秒経過後に吐出ガス過熱度検出部２
３により吐出ガス過熱度ＳＨｄを検出し、メモリ部２１
に予め設定されている吐出ガス過熱度の設定値ＳＨｄ０
からＰＩＤ，ニューロ，ファジー等を用いてマイクロコ
ンピュータ２０により電子膨張弁の開度ＰＬ１が演算さ
れる。前記演算された電子膨張弁への出力開度ＰＬ１
は、第２減圧装置６の膨張弁駆動回路２５ａに伝送さ
れ、第２減圧装置６の開度はＰＬ１となる。一方、熱交
換器流入空気温度検出部２２により室外熱交換器７へ流
入する空気温度Ｔａｏと室内熱交換器３へ流入する空気
温度Ｔａｉを検出し、メモリ部２１に予め設定されてい
る凝縮器出口過冷却度の設定値ＳＣ０を室内熱交換器３
へ流入する空気温度Ｔａｉの関数ｆと室外熱交換器７へ
流入する空気温度Ｔａｏの関数ｇを用いてマイクロコン
ピュータ２０で演算し、最適な凝縮器出口過冷却度の設
定値に変更し、メモリ部２１に記憶する。そして、暖房
用凝縮器出口過冷却度検出部２４ａにより凝縮器出口過
冷却度ＳＣを検出し、前述したメモリ部２１に設定され
ている凝縮器出口過冷却度の設定値ＳＣ０からＰＩＤ，
ニューロ，ファジー等を用いてマイクロコンピュータ２
０により電子膨張弁の開度ＰＬ２が演算される。前記演
算された電子膨張弁への出力開度ＰＬ２は、第１減圧装
置４の膨張弁駆動回路２５ｂに伝送され、第１減圧装置
４の開度はＰＬ２となる。(1) Heating Operation During the heating operation of this refrigeration cycle, as shown in FIG. 8, the discharge gas superheat degree detecting unit 2 is discharged after a predetermined time Δt seconds has elapsed.
3, the discharge gas superheat degree SHd is detected, and the memory unit 21
Set value SHd0 of the discharge gas superheat degree set in advance
From the above, the opening degree PL1 of the electronic expansion valve is calculated by the microcomputer 20 using PID, neuro, fuzzy and the like. The calculated output opening PL1 to the electronic expansion valve
Is transmitted to the expansion valve drive circuit 25a of the second pressure reducing device 6, and the opening degree of the second pressure reducing device 6 becomes PL1. On the other hand, the heat exchanger inflow air temperature detection unit 22 detects the air temperature Tao flowing into the outdoor heat exchanger 7 and the air temperature Tai flowing into the indoor heat exchanger 3, and the condenser unit preset in the memory unit 21. Set the outlet supercooling setting value SC0 to the indoor heat exchanger 3
Is calculated by the microcomputer 20 using the function f of the air temperature Tai flowing into the outdoor heat exchanger 7 and the function g of the air temperature Tao flowing into the outdoor heat exchanger 7, and is changed to an optimum set value of the condenser outlet supercooling degree, and stored in the memory. It is stored in the unit 21. Then, the condenser outlet supercooling degree detection unit 24a detects the condenser outlet supercooling degree SC, and the condenser outlet supercooling degree set value SC0 set in the memory unit 21 from the set value SC0 to PID,
Microcomputer 2 using neuro, fuzzy, etc.
The opening PL2 of the electronic expansion valve is calculated by 0. The calculated output opening PL2 to the electronic expansion valve is transmitted to the expansion valve drive circuit 25b of the first pressure reducing device 4, and the opening of the first pressure reducing device 4 becomes PL2.

【００６１】その結果、前記制御方法によれば、冷媒の
流れに対して受液器５の前方に配設された第１減圧装置
４で凝縮器出口過冷却度を制御することにより、受液器
５に流入する冷媒の乾き度もしくは湿り度を、前記受液
器５から流出する冷媒の乾き度もしくは湿り度と同等に
することができ、受液器５の液面が常に一定となり、冷
凍サイクルを循環する冷媒の組成を安定させることがで
きる。そして、受液器５の後方に配設された第２減圧装
置６で圧縮機１への液戻り量を制御するため、安定した
冷凍サイクルを提供できる。また、室内熱交換器３に流
入する空気の温度Ｔａｉが高くなる場合は、凝縮器出口
過冷却度の設定値ＳＣ０を小さくすることで吐出圧力を
低下させることが可能となり、冷凍サイクルの運転限界
を拡大することができる。また、室内熱交換器３に流入
する空気の温度Ｔａｉや室外熱交換器７に流入する空気
の温度Ｔａｏが低くなる場合は、凝縮器出口過冷却度の
設定値ＳＣ０を大きくすることで吐出圧力を上昇させる
ことができ、暖房能力の向上を図ることができる。さら
に、凝縮器出口過冷却度の設定値を小さくした場合は、
吐出圧力が低下し、圧縮機１への入力量が低下し、省エ
ネルギー運転が可能となり、凝縮器出口過冷却度の設定
値を大きくした場合は、吐出圧力が上昇し、暖房能力の
拡大を図ることができる。このため、空調場の温度が設
定値より離れている場合には、暖房能力を大きくするよ
うに凝縮器出口過冷却度の設定値を大きくし、設定値に
近づいた場合は凝縮器出口過冷却度の設定値を小さくし
て省エネルギー運転を行うようにすれば無駄のない空調
ができる。また、空調場の温度が設定値より離れている
場合でもユーザが省エネルギー運転を所望できるよう
に、リモコン等にスイッチを設けておけば、常に省エネ
ルギー運転を行うようにすることも可能となる。したが
って、これらの運転モードを選択することにより、空調
場に最適でかつユーザが所望する運転を行うことができ
る。As a result, according to the control method, the first outlet of the liquid receiver 5 with respect to the flow of the refrigerant controls the condenser outlet supercooling degree to control the liquid receiving liquid. The dryness or wetness of the refrigerant flowing into the container 5 can be made equal to the dryness or wetness of the refrigerant flowing out of the liquid receiver 5, and the liquid level of the liquid receiver 5 is always constant, so that the freezer is frozen. The composition of the refrigerant circulating in the cycle can be stabilized. Then, since the amount of liquid returned to the compressor 1 is controlled by the second pressure reducing device 6 arranged behind the liquid receiver 5, a stable refrigeration cycle can be provided. When the temperature Tai of the air flowing into the indoor heat exchanger 3 becomes high, the discharge pressure can be lowered by reducing the set value SC0 of the condenser outlet supercooling degree, and the operation limit of the refrigeration cycle can be reduced. Can be expanded. Further, when the temperature Tai of the air flowing into the indoor heat exchanger 3 or the temperature Tao of the air flowing into the outdoor heat exchanger 7 becomes low, the discharge pressure can be increased by increasing the set value SC0 of the condenser outlet supercooling degree. Can be raised, and the heating capacity can be improved. Furthermore, when the set value of the supercooling degree at the condenser outlet is reduced,
The discharge pressure decreases, the input amount to the compressor 1 decreases, energy saving operation becomes possible, and when the set value of the condenser outlet supercooling degree is increased, the discharge pressure increases and the heating capacity is expanded. be able to. Therefore, if the temperature of the air-conditioning area is far from the set value, increase the set value of the condenser outlet supercooling degree to increase the heating capacity, and if it approaches the set value, cool the condenser outlet supercooling degree. If the energy saving operation is performed by reducing the setting value of the degree, air conditioning without waste can be achieved. Further, if a switch is provided on the remote controller or the like so that the user can desire the energy-saving operation even when the temperature of the air-conditioning area is far from the set value, it is possible to always perform the energy-saving operation. Therefore, by selecting one of these operation modes, it is possible to perform an operation that is optimum for the air-conditioned area and that the user desires.

【００６２】（２）冷房運転 この冷房運転時には、図９に示すように、所定時間Δｔ
秒経過後に吐出ガス過熱度検出部２３により吐出ガス過
熱度ＳＨｄを検出し、メモリ部２１に予め設定されてい
る吐出ガス過熱度の設定値ＳＨｄ０からＰＩＤ，ニュー
ロ，ファジー等を用いてマイクロコンピュータ２０によ
り電子膨張弁の開度ＰＬ１が演算される。(2) Cooling operation During this cooling operation, as shown in FIG.
After a lapse of seconds, the discharge gas superheat degree detection unit 23 detects the discharge gas superheat degree SHd, and from the preset value SHd0 of the discharge gas superheat degree preset in the memory unit 21, the microcomputer 20 using PID, neuro, fuzzy, etc. Thus, the opening PL1 of the electronic expansion valve is calculated.

【００６３】前記演算された電子膨張弁への出力開度Ｐ
Ｌ１は、第１減圧装置４の膨張弁駆動回路２５ｂに伝送
され、第１減圧装置４の開度はＰＬ１となる。一方、熱
交換器流入空気温度検出部２２により室外熱交換器７へ
流入する空気の温度Ｔａｏと室内熱交換器３へ流入する
空気の温度Ｔａｉを検出し、メモリ部２１に予め設定さ
れている凝縮器出口過冷却度の設定値ＳＣ０を室内熱交
換器３へ流入する空気の温度Ｔａｉの関数ｆと室外熱交
換器７へ流入する空気の温度Ｔａｏの関数ｇを用いてマ
イクロコンピュータ２０で演算し、最適な凝縮器出口過
冷却度の設定値に変更し、メモリ部２１に記憶する。そ
して、冷房用凝縮器出口過冷却度検出部２４ｂにより凝
縮器出口過冷却度ＳＣを検出し、前述したメモリ部２１
に設定されている凝縮器出口過冷却度の設定値ＳＣ０か
らＰＩＤ，ニューロ，ファジー等を用いてマイクロコン
ピュータ２０により電子膨張弁の開度ＰＬ２が演算され
る。前記演算された電子膨張弁への出力開度ＰＬ２は、
第２減圧装置６の膨張弁駆動回路２５ａに伝送され、第
２減圧装置６の開度はＰＬ２となる。Output opening P to the electronic expansion valve calculated above
L1 is transmitted to the expansion valve drive circuit 25b of the first pressure reducing device 4, and the opening degree of the first pressure reducing device 4 becomes PL1. On the other hand, the heat exchanger inflow air temperature detection unit 22 detects the temperature Tao of the air flowing into the outdoor heat exchanger 7 and the temperature Tai of the air flowing into the indoor heat exchanger 3, and is preset in the memory unit 21. The set value SC0 of the condenser outlet supercooling degree is calculated by the microcomputer 20 using the function f of the temperature Tai of the air flowing into the indoor heat exchanger 3 and the function g of the temperature Tao of the air flowing into the outdoor heat exchanger 7. Then, the value is changed to an optimum set value of the condenser outlet supercooling degree and stored in the memory unit 21. Then, the condenser outlet supercooling degree detection unit 24b detects the condenser outlet supercooling degree SC, and the memory unit 21 described above is detected.
The opening degree PL2 of the electronic expansion valve is calculated by the microcomputer 20 from the set value SC0 of the condenser outlet supercooling degree that is set to PID, neuro, fuzzy and the like. The calculated output opening degree PL2 to the electronic expansion valve is
It is transmitted to the expansion valve drive circuit 25a of the second pressure reducing device 6, and the opening degree of the second pressure reducing device 6 becomes PL2.

【００６４】その結果、前記制御方法によれば、冷媒の
流れに対して受液器５の前方に配設された第２減圧装置
６で凝縮器出口過冷却度を制御することにより、受液器
５に流入する冷媒の乾き度もしくは湿り度を前記受液器
５から流出する冷媒の乾き度もしくは湿り度と同等にす
ることができるため、受液器５の液面が常に一定とな
り、冷凍サイクルを循環する冷媒の組成を安定させるこ
とができる。そして、受液器５の後方に配設された第１
減圧装置４で圧縮機１への液戻り量を制御するため、安
定した冷凍サイクルを提供できる。また、室内熱交換器
３に流入する空気の温度Ｔａｉが高くなる場合は、凝縮
器出口過冷却度の設定値ＳＣ０を小さくすることで吐出
圧力を低下させることが可能となり、冷凍サイクルの運
転限界を拡大することができる。さらに、凝縮器出口過
冷却度の設定値を小さくした場合は、吐出圧力が低下
し、圧縮機１への入力量が低下し、省エネルギー運転が
可能となり、凝縮器出口過冷却度の設定値を大きくした
場合は、吐出圧力が上昇し、室外熱交換器７の廃熱量が
多くなり、冷房能力の拡大を図ることができる。このた
め、空調場の温度が設定値より離れている場合には、冷
房能力を大きくするように凝縮器出口過冷却度の設定値
を大きくし、設定値に近づいた場合は凝縮器出口過冷却
度の設定値を小さくして省エネルギー運転を行うように
すれば、無駄のない空調ができる。また、空調場の温度
が設定値より離れている場合でもユーザが省エネルギー
運転を所望できるようにリモコン等にスイッチを設けて
おけば、常に省エネルギー運転を行うようにすることも
可能となる。したがって、これらの運転モードを選択す
ることにより、空調場に最適でかつユーザが所望する運
転を行うことができる。As a result, according to the control method, the second decompression device 6 arranged in front of the liquid receiver 5 with respect to the flow of the refrigerant controls the degree of supercooling at the outlet of the condenser to thereby obtain the liquid receiving liquid. Since the dryness or wetness of the refrigerant flowing into the container 5 can be made equal to the dryness or wetness of the refrigerant flowing out of the liquid receiver 5, the liquid level of the liquid receiver 5 is always constant, and the freezing The composition of the refrigerant circulating in the cycle can be stabilized. Then, the first device arranged behind the liquid receiver 5
Since the decompression device 4 controls the amount of liquid returned to the compressor 1, a stable refrigeration cycle can be provided. When the temperature Tai of the air flowing into the indoor heat exchanger 3 becomes high, the discharge pressure can be lowered by reducing the set value SC0 of the condenser outlet supercooling degree, and the operation limit of the refrigeration cycle can be reduced. Can be expanded. Further, when the set value of the condenser outlet supercooling degree is decreased, the discharge pressure is reduced, the input amount to the compressor 1 is reduced, and energy saving operation becomes possible. When it is increased, the discharge pressure increases, the amount of waste heat of the outdoor heat exchanger 7 increases, and the cooling capacity can be expanded. Therefore, if the temperature of the air-conditioning area is far from the set value, increase the set value of the condenser outlet supercooling degree to increase the cooling capacity, and if it approaches the set value, cool the condenser outlet supercooling degree. If the energy saving operation is performed by reducing the setting value of the degree, the air conditioning can be performed without waste. Further, even if the temperature of the air-conditioned area is far from the set value, if a switch is provided on the remote controller or the like so that the user can desire the energy-saving operation, it is possible to always perform the energy-saving operation. Therefore, by selecting one of these operation modes, it is possible to perform an operation that is optimum for the air-conditioned area and that the user desires.

【００６５】以上のように、この実施例の冷凍サイクル
の制御方法では、冷媒の流れに対して受液器５の前方に
配設された減圧装置で凝縮器出口過冷却度を制御し、受
液器５の後方に配設された減圧装置で圧縮機１への液戻
り量を制御するため、受液器５の液面を常に一定とする
ことができ、安定した冷凍サイクルを提供できる。ま
た、室内熱交換器３に流入する空気の温度Ｔａｉや室外
熱交換器７に流入する空気の温度Ｔａｏにより、凝縮器
出口過冷却度の設定値ＳＣ０を変更することで、吐出圧
力を低下させたり、上昇させることができるため、運転
限界の拡大や能力の向上を図ることができる。さらに、
凝縮器出口過冷却度の設定値を変更することにより、冷
凍サイクルの運転モードを省エネルギー重視タイプや能
力重視タイプにすることができるため、これらの運転モ
ードを選択することで、空調場に最適でかつユーザの所
望する運転を行うことができる。As described above, according to the refrigerating cycle control method of this embodiment, the decompression device arranged in front of the liquid receiver 5 with respect to the flow of the refrigerant controls the degree of supercooling at the outlet of the condenser to receive the subcooling. Since the amount of liquid returned to the compressor 1 is controlled by the decompression device arranged behind the liquid container 5, the liquid surface of the liquid receiver 5 can be always kept constant, and a stable refrigeration cycle can be provided. Further, the discharge pressure is lowered by changing the set value SC0 of the condenser outlet supercooling degree according to the temperature Tai of the air flowing into the indoor heat exchanger 3 and the temperature Tao of the air flowing into the outdoor heat exchanger 7. Since it can be raised or raised, the operating limit can be expanded and the capability can be improved. further,
By changing the setting value of the condenser outlet supercooling degree, the operation mode of the refrigeration cycle can be set to the energy-saving type or the capacity-oriented type. In addition, it is possible to perform the operation desired by the user.

【００６６】ここで、冷凍サイクルの制御対象として凝
縮器出口過冷却度と吐出ガス過熱度を用いたが、凝縮器
出口過冷却度の代わりとして、受液器の圧力、凝縮器出
口部の冷媒の乾き度もしくは湿り度、受液器内の液面高
さ等、吐出ガス過熱度の代わりとして、吸入ガスの過熱
度または吸入冷媒の乾き度もしくは湿り度、室外熱交換
器出口の過熱度または冷媒の乾き度もしくは湿り度等を
用いた場合も、この実施例と同等の効果がある。Here, although the condenser outlet supercooling degree and the discharge gas superheat degree are used as the control objects of the refrigeration cycle, the pressure of the receiver and the refrigerant at the condenser outlet are used instead of the condenser outlet supercooling degree. As a substitute for the discharge gas superheat, such as the dryness or wetness of the liquid, the height of the liquid level in the receiver, etc., the superheat of the suction gas or the dryness or wetness of the suction refrigerant, the superheat at the outlet of the outdoor heat exchanger, or Even when the dryness or wetness of the refrigerant is used, the same effect as this embodiment is obtained.

【００６７】また、第１減圧装置，第２減圧装置とし
て、本実施例では電子膨張弁を用いているが、キャピラ
リチューブ，温度式膨張弁，もしくは減圧量を調整でき
る機構を備えたものであっても、また第１減圧装置と第
２減圧装置の種類が異なっている場合も、本実施例と同
様の効果がある。Further, although electronic expansion valves are used as the first pressure reducing device and the second pressure reducing device in this embodiment, the first pressure reducing device and the second pressure reducing device are provided with a capillary tube, a temperature type expansion valve, or a mechanism capable of adjusting the amount of pressure reduction. However, even when the types of the first pressure reducing device and the second pressure reducing device are different, the same effect as the present embodiment is obtained.

【００６８】[0068]

【発明の効果】以上説明した本発明の請求項１記載の発
明によれば、室内熱交換器と室外熱交換器の間に受液器
を設け、この受液器に付設する配管の冷却流体の流れ方
向流出側に、ガスと液を混合する気液混合装置を設け、
前記受液器の入口側の冷却流体がガスと液の混合状態と
なるか、もしくは前記受液器内の圧力が前記冷凍サイク
ルの高圧側圧力と低圧側圧力の間の圧力としたため、余
剰冷媒は凝縮器出口の冷媒乾き度が非常に小さい液冷媒
として貯留されるため、封入組成に近い組成の液冷媒が
貯留され、冷凍サイクルを流れる混合冷媒の組成の変化
を抑制することができる結果、冷凍サイクルの運転圧力
の上昇を抑制し、運転限界を拡大し得る効果を有する
外、受液器の前後の配管内を流れる冷媒の状態が気液二
相状態であるため、液冷媒の量を低減することができ、
したがって接続配管が長くなる場合でも、必要冷媒量を
少なくすることができるという効果があり、また運転効
率の向上を図り得る効果もある。According to the invention described in claim 1 of the present invention described above, the liquid receiver is provided between the indoor heat exchanger and the outdoor heat exchanger, and the cooling fluid for the pipe attached to the liquid receiver is provided. A gas-liquid mixing device for mixing gas and liquid is provided on the outflow side in the flow direction of
Since the cooling fluid on the inlet side of the liquid receiver is in a mixed state of gas and liquid, or the pressure inside the liquid receiver is a pressure between the high pressure side pressure and the low pressure side pressure of the refrigeration cycle, the excess refrigerant Since the refrigerant dryness of the condenser outlet is stored as a liquid refrigerant having a very small degree, the liquid refrigerant having a composition close to the enclosed composition is stored, and as a result, it is possible to suppress the change in the composition of the mixed refrigerant flowing through the refrigeration cycle, In addition to having the effect of suppressing the rise in operating pressure of the refrigeration cycle and expanding the operating limit, the state of the refrigerant flowing in the pipes before and after the receiver is a gas-liquid two-phase state, so the amount of liquid refrigerant is Can be reduced,
Therefore, even if the connection pipe becomes long, there is an effect that the required refrigerant amount can be reduced, and there is an effect that the operation efficiency can be improved.

【００６９】また、本発明の請求項２記載の発明によれ
ば、前記受液器を冷凍サイクルの中間圧部に配設し、前
記受液器から流入または流出する冷却流体がガスと液の
混合状態となるように、気液混合装置を配設している結
果、この発明においても、余剰冷媒を凝縮器出口の冷媒
乾き度が非常に小さい液冷媒として貯留することができ
るため、封入組成に近い組成の液冷媒が貯留されるの
で、冷凍サイクルを循環する冷媒組成と封入冷媒組成と
の差が小さくなり、冷媒組成の変化を抑制することがで
き、これにより冷凍サイクルの運転圧力の上昇を抑制
し、運転限界を拡大し得る効果を有する外、受液器の前
後の配管内を流れる冷媒の状態が気液二相状態となるた
め、配管内に占める冷媒の質量が低減され、したがって
冷凍サイクル全体の冷媒量を低減することができるの
で、接続配管が長くなる場合でも必要な冷媒量を少なく
し得る効果があり、また運転効率の向上を図り得る効果
もある。According to the second aspect of the present invention, the liquid receiver is arranged in the intermediate pressure portion of the refrigeration cycle, and the cooling fluid flowing in or out of the liquid receiver is composed of gas and liquid. As a result of disposing the gas-liquid mixing device so as to be in a mixed state, even in the present invention, since the excess refrigerant can be stored as a liquid refrigerant having a very small refrigerant dryness at the condenser outlet, the enclosed composition Since the liquid refrigerant having a composition close to that of the refrigerant is stored, the difference between the refrigerant composition circulating in the refrigeration cycle and the enclosed refrigerant composition can be reduced, and the change in the refrigerant composition can be suppressed, thereby increasing the operating pressure of the refrigeration cycle. In addition to the effect that the operation limit can be expanded, the state of the refrigerant flowing in the pipe before and after the liquid receiver becomes a gas-liquid two-phase state, so the mass of the refrigerant occupied in the pipe is reduced, and Cooling the entire refrigeration cycle It is possible to reduce the amount, a connection pipe is effective which can decrease the amount of refrigerant required even if the longer and the effect of obtaining aims to improve the operating efficiency.

【００７０】また、本発明の請求項３記載の発明によれ
ば、前記気液混合装置として、受液器の塔頂部より受液
器内のガスを抽出するガス管と、受液器内の液を抽出す
る液管と、この液管に設けられた減圧手段とを有するも
のを用いており、この気液混合装置ではガス管を通じて
受液器の塔頂部内のガス冷媒が流出し、液管を通じて受
液器内の液冷媒が流出し、これらガス冷媒と液冷媒とが
混合され、さらに減圧手段により受液器内に流入する気
液二相状態の冷媒に対して、冷媒の乾き度もしくは湿り
度が同じ状態かまたは乾いている状態となるように調整
されるので、冷凍サイクル内に余剰冷媒が発生する場合
は、受液器内に封入組成に近い組成の液冷媒が貯留され
るし、受液器から気液混合装置を通じて常に気液二相状
態の冷媒を導出し得る効果がある。According to the third aspect of the present invention, as the gas-liquid mixing device, a gas pipe for extracting the gas in the liquid receiver from the tower top of the liquid receiver, and the gas pipe in the liquid receiver A liquid pipe for extracting a liquid and one having a decompression means provided in this liquid pipe are used, and in this gas-liquid mixing device, the gas refrigerant in the tower top of the liquid receiver flows out through the gas pipe, The liquid refrigerant in the receiver flows out through the pipe, the gas refrigerant and the liquid refrigerant are mixed, and the degree of dryness of the refrigerant with respect to the gas-liquid two-phase refrigerant flowing into the receiver by the pressure reducing means. Alternatively, since the wetness is adjusted to the same state or to the dry state, when excess refrigerant is generated in the refrigeration cycle, liquid refrigerant having a composition close to the enclosed composition is stored in the receiver. The refrigerant in the gas-liquid two-phase state is always discharged from the receiver through the gas-liquid mixing device. There is that effect.

【００７１】また、本発明の請求項４記載の発明によれ
ば、前記気液混合装置として、受液器内からガスを抽出
する口と、受液器内から液を抽出する口と、前記抽出さ
れたガスと液とを合流させて導出する冷媒導出管とを設
けて構成したものを用いており、その結果この発明にお
いても、受液器内に封入組成に近い組成の液冷媒が貯留
されるし、受液器から気液混合装置を通じて常に気液二
相状態の冷媒を導出し得る効果がある。According to a fourth aspect of the present invention, the gas-liquid mixing device includes a port for extracting gas from the inside of the liquid receiver, a port for extracting liquid from the inside of the liquid receiver, and It is configured by providing a refrigerant outlet pipe that joins and extracts the extracted gas and liquid, and as a result, also in the present invention, a liquid refrigerant having a composition close to the enclosed composition is stored in the receiver. However, there is an effect that the refrigerant in the gas-liquid two-phase state can always be led out from the liquid receiver through the gas-liquid mixing device.

【００７２】また、本発明の請求項５記載の発明によれ
ば、前記第１，第２減圧装置の少なくとも一方に、電子
膨張弁を用いており、これにより冷凍サイクル内を的確
に適応制御し得る効果がある。According to the fifth aspect of the present invention, an electronic expansion valve is used for at least one of the first and second depressurization devices, whereby the refrigeration cycle is appropriately adaptively controlled. There is an effect to obtain.

【００７３】さらに、本発明の請求項６記載の発明によ
れば、少なくとも圧縮機，四方弁，室内熱交換器，第１
減圧装置，受液器，第２減圧装置，室外熱交換器を順次
配管により接続して成る冷凍サイクルを流れる冷媒の流
れ方向に対して、第１，第２減圧装置のうちの受液器の
前方に位置する減圧装置により、室内，室外熱交換器の
うちの凝縮器として作用している熱交換器の冷媒液過冷
却度または受液器内の圧力を制御し、受液器の後方に位
置する減圧装置により、吐出ガス過熱度または吸入ガス
過熱度を制御するようにしており、空気条件が高い場合
には、受液器の前方に位置する減圧装置を制御すること
によって吐出圧力の上昇を抑えることができ、さらに受
液器の後方に位置する減圧装置を制御することによって
圧縮機への液戻り量を最適に制御できるので、冷凍サイ
クルの運転領域の拡大を図り得る効果があり、かつ最適
運転を可能となし得る効果があり、また凝縮器出口過冷
却度の設定値を変更することにより、冷凍サイクルの運
転モードを省エネルギー重視タイプや能力重視タイプと
することができるため、これらの運転モードを選択する
ことにより、空調場に最適でかつユーザの所望する運転
を行い得る効果もある。Further, according to the invention of claim 6 of the present invention, at least the compressor, the four-way valve, the indoor heat exchanger, the first
The decompression device, the liquid receiver, the second decompression device, and the outdoor heat exchanger are sequentially connected by piping to the flow direction of the refrigerant flowing through the refrigeration cycle. The decompression device located in the front controls the degree of supercooling of the refrigerant liquid in the heat exchanger acting as the condenser of the indoor and outdoor heat exchangers or the pressure in the receiver, and The pressure reducing device located controls the discharge gas superheat or the suction gas superheat, and when the air condition is high, the discharge pressure rises by controlling the pressure reducing device located in front of the liquid receiver. The amount of liquid returned to the compressor can be optimally controlled by controlling the decompression device located behind the liquid receiver, which has the effect of expanding the operating range of the refrigeration cycle. And no optimal operation is possible In addition, the refrigeration cycle operation mode can be changed to energy-saving type or capacity-oriented type by changing the set value of the condenser outlet supercooling degree. In addition, there is an effect that it is most suitable for an air-conditioning area and that the user can perform a desired operation.

【図面の簡単な説明】[Brief description of drawings]

【図１】本発明冷凍サイクルの一実施例を示す系統図で
ある。FIG. 1 is a system diagram showing an embodiment of a refrigeration cycle of the present invention.

【図２】混合冷媒を用いた場合のアキュムレータ内の気
液平衡状態図である。FIG. 2 is a vapor-liquid equilibrium state diagram in an accumulator when a mixed refrigerant is used.

【図３】混合冷媒を用いた場合の受液器内の気液平衡図
である。FIG. 3 is a vapor-liquid equilibrium diagram in a liquid receiver when a mixed refrigerant is used.

【図４】本発明にかかる冷凍サイクルに付設される気液
混合装置の一実施例を示す縦断面図である。FIG. 4 is a vertical sectional view showing an embodiment of a gas-liquid mixing device attached to the refrigeration cycle according to the present invention.

【図５】本発明にかかる冷凍サイクルに付設される気液
混合装置の他の実施例を示す縦断面図である。FIG. 5 is a vertical cross-sectional view showing another embodiment of the gas-liquid mixing device attached to the refrigeration cycle according to the present invention.

【図６】本発明にかかる冷凍サイクルに付設される気液
混合装置のさらに他の実施例を示す縦断面図である。FIG. 6 is a vertical sectional view showing still another embodiment of the gas-liquid mixing device attached to the refrigeration cycle according to the present invention.

【図７】冷凍サイクルを流れる混合冷媒の冷媒組成と冷
凍サイクルの運転効率の関係を示した図である。FIG. 7 is a diagram showing the relationship between the refrigerant composition of the mixed refrigerant flowing in the refrigeration cycle and the operation efficiency of the refrigeration cycle.

【図８】本発明冷凍サイクルの制御方法の一実施例を示
すもので、暖房運転時のフローチャートである。FIG. 8 shows an embodiment of the control method of the refrigeration cycle of the present invention, and is a flow chart during heating operation.

【図９】同制御方法の冷房運転時のフローチャートであ
る。FIG. 9 is a flowchart of the control method during a cooling operation.

【符号の説明】[Explanation of symbols]

１…圧縮機、３…室内熱交換器、４…第１減圧装置、５
…受液器、６…第２減圧装置、７…室外熱交換器、８…
アキュムレータ、１０…気液混合装置、１１ａ，１１ｂ
…冷媒液導入出管、１２ａ，１２ｂ…減圧手段である乾
き度調整用減圧装置、１３ａ，１３ｂ…冷媒ガス導出
管、１４ａ，１４ｂ…冷媒液導出管、１５ａ，１５ｂ…
冷媒導入出管、１６ａ，１６ｂ…冷媒導入出用のＵ字
管、１７ａ，１７ｂ…ガス穴、１８ａ，１８ｂ…液穴、
２０…マイクロコンピュータ、２１…メモリ部、２２…
熱交換器流入空気温度検出部、２３…吐出ガス過熱度検
出部、２４ａ…暖房用凝縮器出口過冷却度検出部、２４
ｂ…冷房用凝縮器出口過冷却度検出部、２５ａ，２５ｂ
…膨張弁駆動回路、２６ａ〜２６ｅ…温度検出器。1 ... Compressor, 3 ... Indoor heat exchanger, 4 ... First decompression device, 5
... liquid receiver, 6 ... second pressure reducing device, 7 ... outdoor heat exchanger, 8 ...
Accumulator, 10 ... Gas-liquid mixing device, 11a, 11b
... Refrigerant liquid inlet / outlet pipe, 12a, 12b ... Decompression device for dryness adjustment which is a pressure reducing device, 13a, 13b ... Refrigerant gas outlet pipe, 14a, 14b ... Refrigerant liquid outlet pipe, 15a, 15b ...
Refrigerant inlet / outlet pipe, 16a, 16b ... U-shaped pipe for refrigerant inlet / outlet, 17a, 17b ... Gas hole, 18a, 18b ... Liquid hole,
20 ... Microcomputer, 21 ... Memory part, 22 ...
Heat exchanger inflow air temperature detection unit, 23 ... Discharge gas superheat degree detection unit, 24a ... Heating condenser outlet supercooling degree detection unit, 24
b ... Cooling condenser outlet supercooling degree detection unit, 25a, 25b
... Expansion valve drive circuit, 26a-26e ... Temperature detector.

───────────────────────────────────────────────────── フロントページの続き (72)発明者 遠藤 剛 東京都千代田区神田駿河台四丁目６番地 株式会社日立製作所空調システム事業部内 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tsuyoshi Endo 4-6, Surugadai Kanda, Chiyoda-ku, Tokyo Inside Hitachi Air Conditioning Systems Division

Claims (6)

【特許請求の範囲】[Claims] 【請求項１】 少なくとも圧縮機，室内熱交換器，第１
減圧装置，第２減圧装置，室外熱交換器を順次配管によ
り接続して成る冷凍サイクルに、沸点の異なる少なくと
も二種類の冷媒を混合して成る非共沸混合冷媒を封入
し、前記室内熱交換器と室外熱交換器の間に受液器を設
けて成る冷凍サイクルにおいて、前記受液器に付設する
配管内を流れる冷却流体の流れ方向流出側に、ガスと液
を混合する気液混合装置を設け、前記受液器の入口側の
冷却流体がガスと液の混合状態となるか、もしくは前記
受液器内の圧力が前記冷凍サイクルの高圧側圧力と低圧
側圧力の間の圧力としたことを特徴とする冷凍サイク
ル。1. At least a compressor, an indoor heat exchanger, a first
A non-azeotropic mixed refrigerant formed by mixing at least two kinds of refrigerants having different boiling points is enclosed in a refrigeration cycle in which a pressure reducing device, a second pressure reducing device, and an outdoor heat exchanger are sequentially connected by piping, and the indoor heat exchange is performed. In a refrigeration cycle in which a receiver is provided between the receiver and the outdoor heat exchanger, a gas-liquid mixing device for mixing gas and liquid on the outflow side of the cooling fluid flowing in the pipe attached to the receiver And the cooling fluid on the inlet side of the receiver is in a mixed state of gas and liquid, or the pressure in the receiver is set to a pressure between the high pressure side pressure and the low pressure side pressure of the refrigeration cycle. A refrigeration cycle characterized by that. 【請求項２】 少なくとも圧縮機，室内熱交換器，第１
減圧装置，第２減圧装置，室外熱交換器を順次配管によ
り接続して成る冷凍サイクルに、沸点の異なる少なくと
も二種類の冷媒を混合して成る非共沸混合冷媒を封入
し、前記室内熱交換器と室外熱交換器の間に受液器を設
けて成る冷凍サイクルにおいて、前記受液器を前記冷凍
サイクルの中間圧部に配設し、前記受液器から流入ある
いは流出する冷却流体をガスと液の混合状態とする気液
混合装置を配設したことを特徴とする冷凍サイクル。2. At least a compressor, an indoor heat exchanger, a first
A non-azeotropic mixed refrigerant formed by mixing at least two kinds of refrigerants having different boiling points is enclosed in a refrigeration cycle in which a pressure reducing device, a second pressure reducing device, and an outdoor heat exchanger are sequentially connected by piping, and the indoor heat exchange is performed. In a refrigeration cycle in which a liquid receiver is provided between the heat exchanger and the outdoor heat exchanger, the liquid receiver is arranged at an intermediate pressure portion of the refrigeration cycle, and a cooling fluid flowing in or out of the liquid receiver is gas. A refrigerating cycle comprising a gas-liquid mixing device for mixing the liquid and the liquid. 【請求項３】 前記気液混合装置として、前記受液器の
塔頂部より受液器内のガスを抽出するガス管と、前記受
液器内の液を抽出する液管と、この液管に設けられた減
圧手段とを有して構成したものを用いたことを特徴とす
る請求項１または２記載の冷凍サイクル。3. The gas-liquid mixing device, a gas pipe for extracting gas in the liquid receiver from the top of the liquid receiver, a liquid pipe for extracting liquid in the liquid receiver, and the liquid pipe. The refrigerating cycle according to claim 1 or 2, wherein the refrigerating cycle is configured to have a depressurizing means provided in the. 【請求項４】 前記気液混合装置として、前記受液器内
からガスを抽出する口と、前記受液器内から液を抽出す
る口と、前記抽出されたガスと液とを混合させて導出す
る冷媒導出管とを設けて構成したものを用いたことを特
徴とする請求項１または２記載の冷凍サイクル。4. The gas-liquid mixing device, wherein a port for extracting gas from the inside of the receiver, a port for extracting liquid from inside of the receiver, and the mixture of the extracted gas and liquid The refrigerating cycle according to claim 1 or 2, wherein a refrigerating cycle for discharging the refrigerant is used. 【請求項５】 前記第１減圧装置と第２減圧装置の少な
くとも一方に、電子膨張弁を用いたことを特徴とする請
求項１または２記載の冷凍サイクル。5. The refrigeration cycle according to claim 1, wherein an electronic expansion valve is used for at least one of the first pressure reducing device and the second pressure reducing device. 【請求項６】 少なくとも圧縮機，四方弁，室内熱交換
器，第１減圧装置，受液器，第２減圧装置，室外熱交換
器を順次配管により接続して成る冷凍サイクルに、沸点
の異なる少なくとも二種類の冷媒を混合して成る非共沸
混合冷媒を封入し、前記第１減圧装置または第２減圧装
置により冷凍サイクルを制御する冷凍サイクルの制御方
法において、前記冷凍サイクルを流れる冷媒の流れ方向
に対して、第１，第２減圧装置のうちの受液器の前方に
位置する減圧装置により、室内，室外熱交換器のうちの
凝縮器として作用している熱交換器の冷媒液過冷却度ま
たは受液器内の圧力を制御し、受液器の後方に位置する
減圧装置により、吐出ガス過熱度または吸入ガス過熱度
を制御することを特徴とする冷凍サイクルの制御方法。6. A refrigeration cycle having at least a compressor, a four-way valve, an indoor heat exchanger, a first decompressor, a liquid receiver, a second decompressor, and an outdoor heat exchanger, which are connected in sequence by piping to have different boiling points. In a method for controlling a refrigeration cycle in which a non-azeotropic mixed refrigerant formed by mixing at least two kinds of refrigerant is sealed and the refrigeration cycle is controlled by the first pressure reducing device or the second pressure reducing device, a flow of the refrigerant flowing through the refrigeration cycle. With respect to the direction, the pressure reducing device located in front of the liquid receiver of the first and second pressure reducing devices causes the refrigerant liquid flow of the heat exchanger acting as the condenser of the indoor and outdoor heat exchangers. A method for controlling a refrigeration cycle, characterized in that the degree of cooling or the pressure in the liquid receiver is controlled, and the degree of discharge gas superheat or the degree of suction gas superheat is controlled by a pressure reducing device located behind the liquid receiver.