JP2017075707A - Air conditioner - Google Patents

Air conditioner Download PDF

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JP2017075707A
JP2017075707A JP2015201936A JP2015201936A JP2017075707A JP 2017075707 A JP2017075707 A JP 2017075707A JP 2015201936 A JP2015201936 A JP 2015201936A JP 2015201936 A JP2015201936 A JP 2015201936A JP 2017075707 A JP2017075707 A JP 2017075707A
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outdoor
pressure gas
heat exchanger
pipe
compressor
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JP6539560B2 (en
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達弘 安田
Tatsuhiro Yasuda
達弘 安田
隆博 加藤
Takahiro Kato
隆博 加藤
正幸 瀧川
Masayuki Takigawa
正幸 瀧川
篤 塩谷
Atsushi Shiotani
篤 塩谷
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Mitsubishi Heavy Industries Ltd
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Mitsubishi Heavy Industries Ltd
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B13/00—Compression machines, plants or systems, with reversible cycle
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B41/00—Fluid-circulation arrangements
    • F25B41/20—Disposition of valves, e.g. of on-off valves or flow control valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B41/00—Fluid-circulation arrangements
    • F25B41/20—Disposition of valves, e.g. of on-off valves or flow control valves
    • F25B41/24—Arrangement of shut-off valves for disconnecting a part of the refrigerant cycle, e.g. an outdoor part
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2313/00—Compression machines, plants or systems with reversible cycle not otherwise provided for
    • F25B2313/005—Outdoor unit expansion valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2313/00—Compression machines, plants or systems with reversible cycle not otherwise provided for
    • F25B2313/007—Compression machines, plants or systems with reversible cycle not otherwise provided for three pipes connecting the outdoor side to the indoor side with multiple indoor units
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2313/00—Compression machines, plants or systems with reversible cycle not otherwise provided for
    • F25B2313/023—Compression machines, plants or systems with reversible cycle not otherwise provided for using multiple indoor units
    • F25B2313/0231—Compression machines, plants or systems with reversible cycle not otherwise provided for using multiple indoor units with simultaneous cooling and heating
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2313/00—Compression machines, plants or systems with reversible cycle not otherwise provided for
    • F25B2313/023—Compression machines, plants or systems with reversible cycle not otherwise provided for using multiple indoor units
    • F25B2313/0232—Compression machines, plants or systems with reversible cycle not otherwise provided for using multiple indoor units with bypasses
    • F25B2313/02323—Compression machines, plants or systems with reversible cycle not otherwise provided for using multiple indoor units with bypasses during heating
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2313/00—Compression machines, plants or systems with reversible cycle not otherwise provided for
    • F25B2313/023—Compression machines, plants or systems with reversible cycle not otherwise provided for using multiple indoor units
    • F25B2313/0233—Compression machines, plants or systems with reversible cycle not otherwise provided for using multiple indoor units in parallel arrangements
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2313/00—Compression machines, plants or systems with reversible cycle not otherwise provided for
    • F25B2313/025—Compression machines, plants or systems with reversible cycle not otherwise provided for using multiple outdoor units
    • F25B2313/0253—Compression machines, plants or systems with reversible cycle not otherwise provided for using multiple outdoor units in parallel arrangements
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2313/00—Compression machines, plants or systems with reversible cycle not otherwise provided for
    • F25B2313/027—Compression machines, plants or systems with reversible cycle not otherwise provided for characterised by the reversing means
    • F25B2313/02743—Compression machines, plants or systems with reversible cycle not otherwise provided for characterised by the reversing means using three four-way valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2400/00—General features or devices for refrigeration machines, plants or systems, combined heating and refrigeration systems or heat-pump systems, i.e. not limited to a particular subgroup of F25B
    • F25B2400/07—Details of compressors or related parts
    • F25B2400/075—Details of compressors or related parts with parallel compressors
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2400/00—General features or devices for refrigeration machines, plants or systems, combined heating and refrigeration systems or heat-pump systems, i.e. not limited to a particular subgroup of F25B
    • F25B2400/13—Economisers
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2500/00—Problems to be solved
    • F25B2500/02—Increasing the heating capacity of a reversible cycle during cold outdoor conditions
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2600/00—Control issues
    • F25B2600/01—Timing
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B41/00—Fluid-circulation arrangements
    • F25B41/30—Expansion means; Dispositions thereof
    • F25B41/37—Capillary tubes

Abstract

PROBLEM TO BE SOLVED: To provide an air conditioner that can suppress decline in capacity when an outdoor heat exchanger is used as an evaporator without using a control valve having a large bore diameter.SOLUTION: An outdoor unit 1 includes: compressors 10 each having a discharge side continued to a high-pressure gas pipe 5 and a suction side continued to a low-pressure gas pipe 7; a plurality of outdoor heat exchangers 12a-12c each continued to a liquid pipe 9 in parallel; a plurality of outdoor four-way valves 14a-14c each disposed between the compressor 10 and each of the outdoor heat exchangers 12a-12c for selectively switching a high-pressure gas flow passage and a low-pressure gas flow passage; and outdoor control valves 27a-27c disposed at least between the outdoor four-way valves 14a-14c and the discharge sides of the compressors 10 to control a flow from the compressors 10 to the outdoor four-way valves 14a-14c.SELECTED DRAWING: Figure 1

Description

本発明は、高圧ガス管、低圧ガス管および液管によって接続された室外機と室内機とを備えた空気調和装置に関する。   The present invention relates to an air conditioner including an outdoor unit and an indoor unit connected by a high-pressure gas pipe, a low-pressure gas pipe, and a liquid pipe.

一般に、圧縮機および室外熱交換器を有する室外機と、室内熱交換器を有する複数台の室内機とを備え、室外機と室内機とが高圧ガス管、低圧ガス管、および液管によって接続され、室内機を独立して冷房運転または暖房運転を可能とした空気調和装置が知られている（例えば、特許文献１参照）。この種の空気調和装置では、圧縮機と室外熱交換器との間に、圧縮機の吐出側から室外熱交換器へと向かう高圧ガス流路と、室外熱交換器から圧縮機の吸込側へと向かう低圧流路とを切り換える室外四方弁を備えると共に、室外四方弁の低圧ガス流路が選択された場合に、圧縮機の吐出側から圧縮機の吸込側（低圧ガス管）に冷媒を導くキャピラリチューブを室外四方弁に設け、室外四方弁の手前で液冷媒が溜まる事態を防止している。   Generally, an outdoor unit having a compressor and an outdoor heat exchanger and a plurality of indoor units having an indoor heat exchanger are connected to each other by a high pressure gas pipe, a low pressure gas pipe, and a liquid pipe. There is known an air conditioner that enables an indoor unit to perform a cooling operation or a heating operation independently (see, for example, Patent Document 1). In this type of air conditioner, a high-pressure gas flow path from the discharge side of the compressor to the outdoor heat exchanger, between the compressor and the outdoor heat exchanger, and from the outdoor heat exchanger to the suction side of the compressor When the low-pressure gas flow path of the outdoor four-way valve is selected, the refrigerant is guided from the discharge side of the compressor to the suction side (low-pressure gas pipe) of the compressor. A capillary tube is provided in the outdoor four-way valve to prevent liquid refrigerant from accumulating in front of the outdoor four-way valve.

特開２００６−１２５７６１号公報JP 2006-125761 A

ところで、上記した空気調和装置は、複数の室内機を独立して冷房運転または暖房運転を可能とするものであるため、室外熱交換器を並列に複数設けることで、蒸発熱量と凝縮熱量との熱バランスを細かく制御することができ有効となる。この構成では、例えば、低外気温下での冷房性能を向上させるため、凝縮器として使用しない室外熱交換器には、該室外熱交換器内に冷媒が溜まらないように、圧縮機の吐出側から室外熱交換器への冷媒の流れを止める制御弁が必要である。   By the way, since the above-described air conditioner enables a plurality of indoor units to perform a cooling operation or a heating operation independently, by providing a plurality of outdoor heat exchangers in parallel, the amount of heat of evaporation and the amount of heat of condensation are reduced. The heat balance can be finely controlled, which is effective. In this configuration, for example, in order to improve the cooling performance under a low outdoor temperature, an outdoor heat exchanger that is not used as a condenser has a discharge side of the compressor so that refrigerant does not accumulate in the outdoor heat exchanger. There is a need for a control valve that stops the flow of refrigerant from the outdoor heat exchanger to the outdoor heat exchanger.

この場合、制御弁を室外熱交換器の手前、すなわち、室外四方弁と室外熱交換器との間に設ける構成が想定される。しかし、室外熱交換器を蒸発器として使用する場合、室外四方弁と室外熱交換器とを接続する管路には、高圧ガスよりも膨張した低圧ガスが流通する。このため、室外四方弁と室外熱交換器との間に制御弁を設ける構成では、圧力損失による能力低下を抑制するために、双方向の流れを許容しつつ口径の大きな制御弁を設ける必要があった。また、室外熱交換器を蒸発器として使用する場合には、室外四方弁に設けたキャピラリチューブを通じて、圧縮機の吐出側から圧縮機の吸込側に少量ながらも冷媒が流出するため、能力低下の要因となっていた。   In this case, a configuration in which the control valve is provided in front of the outdoor heat exchanger, that is, between the outdoor four-way valve and the outdoor heat exchanger is assumed. However, when the outdoor heat exchanger is used as an evaporator, a low-pressure gas expanded from the high-pressure gas flows through a pipe line connecting the outdoor four-way valve and the outdoor heat exchanger. For this reason, in the configuration in which the control valve is provided between the outdoor four-way valve and the outdoor heat exchanger, it is necessary to provide a control valve having a large diameter while permitting bidirectional flow in order to suppress a decrease in capacity due to pressure loss. there were. In addition, when the outdoor heat exchanger is used as an evaporator, a small amount of refrigerant flows out from the discharge side of the compressor to the suction side of the compressor through the capillary tube provided in the outdoor four-way valve. It was a factor.

本発明は、上記の事情に鑑みてなされたものであり、口径の大きな制御弁を用いることなく、室外熱交換器を蒸発器として使用する場合の能力低下を抑制できる空気調和装置を提供することを目的とする。   This invention is made in view of said situation, and provides the air conditioning apparatus which can suppress the capability fall at the time of using an outdoor heat exchanger as an evaporator, without using a control valve with a large diameter. With the goal.

上述した課題を解決し、目的を達成するために、本発明は、圧縮機および室外熱交換器を有する室外機と、室内熱交換器を有する複数台の室内機とを備え、室外機と室内機とが高圧ガス管、低圧ガス管、および液管によって接続され、室内機を独立して冷房運転または暖房運転可能とした空気調和装置であって、室外機は、高圧ガス管に吐出側が連なり、低圧ガス管に吸込側が連なる圧縮機と、液管に並列に連なる複数の室外熱交換器と、圧縮機とそれぞれの室外熱交換器との間に、圧縮機の吐出側から室外熱交換器へと向かう高圧ガス流路と、室外熱交換器から圧縮機の吸込側へと向かう低圧ガス流路とをそれぞれ選択的に切り換える複数の室外四方弁と、室外四方弁の低圧ガス流路が選択された場合に、圧縮機の吐出側と連通する室外四方弁のポートに一端が接続され、他端が圧縮機の吸込側に連なる複数のキャピラリチューブと、少なくとも室外四方弁の１つと圧縮機の吐出側との間に配置されて、該圧縮機から室外四方弁への流れを制御する室外制御弁とを備えた。   In order to solve the above-described problems and achieve the object, the present invention includes an outdoor unit having a compressor and an outdoor heat exchanger, and a plurality of indoor units having an indoor heat exchanger. Is an air conditioner that is connected with a high-pressure gas pipe, a low-pressure gas pipe, and a liquid pipe to enable the indoor unit to perform cooling operation or heating operation independently. The outdoor unit is connected to the high-pressure gas pipe at the discharge side. A compressor whose suction side is connected to the low pressure gas pipe, a plurality of outdoor heat exchangers connected in parallel to the liquid pipe, and an outdoor heat exchanger from the discharge side of the compressor between the compressor and each of the outdoor heat exchangers Multiple outdoor four-way valves that selectively switch between the high-pressure gas flow path to the outside and the low-pressure gas flow path from the outdoor heat exchanger to the suction side of the compressor, and the low-pressure gas flow path of the outdoor four-way valve are selected In the outdoor communication with the discharge side of the compressor. One end is connected to the port of the valve, and the other end is arranged between at least one of the outdoor four-way valves and the discharge side of the compressor, and is connected to the outdoor side of the compressor. And an outdoor control valve for controlling the flow to the four-way valve.

この構成によれば、少なくとも室外四方弁の１つと圧縮機の吐出側との間に配置されて、該圧縮機から室外四方弁への流れを制御する室外制御弁を備えたため、この室外制御弁を閉じることにより、該室外制御弁を設けた経路の室外熱交換器に冷媒が流れなくなる。このため、冷房運転または暖房運転時に容量として不要な室外熱交換器を遮断することができ、例えば、低外気温下の冷房運転時に、凝縮器として使用する室外熱交換器の容量を抑えることができ、使用しない室外熱交換器内に液冷媒が溜まることを防止できる。また、室外制御弁を室外四方弁と圧縮機の吐出側との間に配置したことにより、室外熱交換器を蒸発器として使用する場合に、室外制御弁が冷媒の流路から外れるため、口径の大きな室外制御弁を要することがない。さらに、室外熱交換器を蒸発器として使用する場合に、室外制御弁を閉じることにより、キャピラリチューブを通じて、圧縮機の吐出側から圧縮機の吸込側への冷媒の流れを遮断し、能力低下を抑制できる。   According to this configuration, the outdoor control valve is disposed between at least one of the outdoor four-way valves and the discharge side of the compressor, and controls the flow from the compressor to the outdoor four-way valve. Is closed so that the refrigerant does not flow to the outdoor heat exchanger in the path provided with the outdoor control valve. For this reason, an unnecessary outdoor heat exchanger can be shut off during cooling operation or heating operation, and for example, the capacity of the outdoor heat exchanger used as a condenser can be suppressed during cooling operation under a low outdoor temperature. This can prevent liquid refrigerant from accumulating in the outdoor heat exchanger that is not used. In addition, since the outdoor control valve is arranged between the outdoor four-way valve and the discharge side of the compressor, when the outdoor heat exchanger is used as an evaporator, the outdoor control valve is removed from the refrigerant flow path. A large outdoor control valve is not required. Furthermore, when using an outdoor heat exchanger as an evaporator, closing the outdoor control valve blocks the flow of refrigerant from the discharge side of the compressor to the suction side of the compressor through the capillary tube, thereby reducing the capacity. Can be suppressed.

この構成において、室外熱交換器は、熱交換容量がそれぞれ異なる構成とし、室外制御弁は、少なくとも熱交換容量が最も大きな室外熱交換器に対応する室外四方弁と圧縮機の吐出側との間に配置されても良い。この構成によれば、熱交換容量が最も大きな室外熱交換器への冷媒の流れを遮断できるため、例えば、低外気温下の冷房運転時に、凝縮器として使用する室外熱交換器の容量を簡単に抑えることができ、使用しない室外熱交換器内に液冷媒が溜まることを防止できる。   In this configuration, the outdoor heat exchangers have different heat exchange capacities, and the outdoor control valve is located between the outdoor four-way valve corresponding to the outdoor heat exchanger having at least the largest heat exchange capacity and the discharge side of the compressor. May be arranged. According to this configuration, since the refrigerant flow to the outdoor heat exchanger having the largest heat exchange capacity can be blocked, for example, the capacity of the outdoor heat exchanger used as a condenser can be easily reduced during cooling operation at a low outdoor temperature. The liquid refrigerant can be prevented from accumulating in the outdoor heat exchanger that is not used.

また、室外制御弁は、室外四方弁と圧縮機の吐出側との間にそれぞれ配置されてもよい。この構成によれば、空調負荷に応じて、使用する室外熱交換器を細かく制御することができる。   The outdoor control valve may be disposed between the outdoor four-way valve and the discharge side of the compressor. According to this structure, the outdoor heat exchanger to be used can be finely controlled according to the air conditioning load.

また、室外四方弁の低圧ガス流路が選択された場合、室外制御弁を閉じると共に、定期的もしくは不定期に、該室外制御弁を所定時間だけ開放しても良い。この構成によれば、室外制御弁と圧縮機の吐出側との間に溜まった冷媒を、キャピラリチューブを通じて流出できる。   When the low-pressure gas flow path of the outdoor four-way valve is selected, the outdoor control valve may be closed and the outdoor control valve may be opened for a predetermined time regularly or irregularly. According to this configuration, the refrigerant accumulated between the outdoor control valve and the discharge side of the compressor can flow out through the capillary tube.

本発明によれば、少なくとも室外四方弁の１つと圧縮機の吐出側との間に配置されて、該圧縮機から室外四方弁への流れを制御する室外制御弁を備えたため、口径の大きな室外制御弁を用いることなく、室外熱交換器を蒸発器として使用する場合の能力低下を抑制できる。   According to the present invention, since the outdoor control valve that is arranged between at least one of the outdoor four-way valves and the discharge side of the compressor and controls the flow from the compressor to the outdoor four-way valve is provided, Without using a control valve, it is possible to suppress a decrease in capacity when the outdoor heat exchanger is used as an evaporator.

図１は、本実施形態にかかる冷暖房フリーマルチエアコンの概略構成図である。FIG. 1 is a schematic configuration diagram of an air conditioning free multi air conditioner according to the present embodiment. 図２は、低外気温下における冷房主体運転の運転パターンを示した概略構成図である。FIG. 2 is a schematic configuration diagram showing an operation pattern of the cooling main operation under a low outside air temperature.

以下に、本発明に係る実施形態を図面に基づいて詳細に説明する。なお、この実施形態によりこの発明が限定されるものではない。また、実施形態における構成要素には、当業者が置換可能かつ容易なもの、あるいは実質的に同一のものが含まれる。さらに、以下に記載した構成要素は適宜組み合わせることが可能である。   Embodiments according to the present invention will be described below in detail with reference to the drawings. In addition, this invention is not limited by this embodiment. In addition, the constituent elements in the embodiments include those that can be easily replaced by those skilled in the art or those that are substantially the same. Furthermore, the constituent elements described below can be appropriately combined.

図１は、本実施形態にかかる冷暖房フリーマルチエアコンの概略構成図である。冷暖房フリーマルチエアコン（空気調和装置）１００は、１台の室外ユニット（室外機）１と、複数台（例えば４台）の室内ユニット（室内機）３ａ，３ｂ，３ｃ，３ｄと、これら各ユニットを接続する高圧ガス管５、低圧ガス管７および液管９とを備えている。室内ユニットについて特段区別する必要がない場合には、単に室内ユニット３と称する。冷暖房フリーマルチエアコン１００は、室内ユニット３ａ〜３ｄのそれぞれで冷房運転または暖房運転を独立に行うことができる。図１では、すべての室内ユニット３ａ〜３ｄで暖房運転を行う運転パターンを示している。   FIG. 1 is a schematic configuration diagram of an air conditioning free multi air conditioner according to the present embodiment. The cooling / heating free multi air conditioner (air conditioner) 100 includes one outdoor unit (outdoor unit) 1, a plurality of (for example, four) indoor units (indoor units) 3 a, 3 b, 3 c, 3 d, and each of these units Are provided with a high pressure gas pipe 5, a low pressure gas pipe 7 and a liquid pipe 9. When there is no need to distinguish between indoor units, they are simply referred to as indoor units 3. The cooling / heating free multi-air conditioner 100 can independently perform a cooling operation or a heating operation in each of the indoor units 3a to 3d. In FIG. 1, the operation pattern which performs heating operation in all the indoor units 3a-3d is shown.

室外ユニット１は、複数台（例えば２台）の圧縮機１０ａ，１０ｂと、複数台（例えば３台）の室外熱交換器１２ａ，１２ｂ，１２ｃと、を備えている。これら圧縮機及び室外熱交換器についても、特段区別する必要がない場合には、単に圧縮機１０、室外熱交換器１２と称する。   The outdoor unit 1 includes a plurality of (for example, two) compressors 10a and 10b and a plurality of (for example, three) outdoor heat exchangers 12a, 12b, and 12c. These compressors and outdoor heat exchangers are also simply referred to as a compressor 10 and an outdoor heat exchanger 12 when it is not necessary to distinguish between them.

圧縮機１０ａ，１０ｂは、冷媒を圧縮するものであり、好適にはスクロールコンプレッサが用いられる。これらの圧縮機１０ａ，１０ｂは、要求される能力に応じて、２台同時に運転する場合もあり、また、１台のみ運転させ、他の１台をバックアップとする場合もある。冷媒としては、例えばＲ４０１Ａが用いられる。このＲ４０１Ａは、従来の冷媒であるＲ２２やＲ４０７Ｃに比べて約１．４倍（５℃）の密度を有し、約１．６倍（５℃）の高圧となる。このような高密度高圧冷媒は、高い冷凍能力を発揮し、圧力損失も少ないという利点を有する。   The compressors 10a and 10b compress the refrigerant, and a scroll compressor is preferably used. Two of these compressors 10a and 10b may be operated simultaneously depending on the required capacity, or only one unit may be operated and the other unit may be used as a backup. For example, R401A is used as the refrigerant. This R401A has a density of about 1.4 times (5 ° C.) and about 1.6 times (5 ° C.) higher pressure than the conventional refrigerants R22 and R407C. Such a high-density and high-pressure refrigerant has the advantages of exhibiting a high refrigeration capacity and low pressure loss.

圧縮機１０ａ，１０ｂで圧縮された冷媒は、高圧ガス冷媒となり、冷媒吐出管２１ａ，２１ｂをそれぞれ流れた後、室外高圧ガス管２１にて合流する。この室外高圧ガス管２１は、上記した高圧ガス管５に接続される。室外高圧ガス管２１は、分岐点２３で分岐される高圧分岐管２４を有し、この高圧分岐管２４は、更に第１高圧分岐管２４ａ、第２高圧分岐管２４ｂ及び第３高圧分岐管２４ｃの３つに分岐されている。第１高圧分岐管２４ａ、第２高圧分岐管２４ｂ及び第３高圧分岐管２４ｃは、それぞれ第１室外制御弁２７ａ、第２室外制御弁２７ｂ及び第３室外制御弁２７ｃを介して、第１室外四方弁１４ａ、第２室外四方弁１４ｂ及び第３室外四方弁１４ｃに接続されている。これら第１〜第３室外四方弁１４ａ〜１４ｃ、及び、第１〜第３室外制御弁２７ａ〜２７ｃについては、後に詳述する。   The refrigerant compressed by the compressors 10a and 10b becomes a high-pressure gas refrigerant, flows through the refrigerant discharge pipes 21a and 21b, and then merges in the outdoor high-pressure gas pipe 21. The outdoor high pressure gas pipe 21 is connected to the high pressure gas pipe 5 described above. The outdoor high-pressure gas pipe 21 has a high-pressure branch pipe 24 branched at a branch point 23. The high-pressure branch pipe 24 further includes a first high-pressure branch pipe 24a, a second high-pressure branch pipe 24b, and a third high-pressure branch pipe 24c. It is branched into three. The first high pressure branch pipe 24a, the second high pressure branch pipe 24b, and the third high pressure branch pipe 24c are connected to the first outdoor side via the first outdoor control valve 27a, the second outdoor control valve 27b, and the third outdoor control valve 27c, respectively. The four-way valve 14a is connected to the second outdoor four-way valve 14b and the third outdoor four-way valve 14c. The first to third outdoor four-way valves 14a to 14c and the first to third outdoor control valves 27a to 27c will be described in detail later.

また、圧縮機１０ａ，１０ｂの吸込側には、それぞれ冷媒吸込管２２ａ，２２ｂが設けられ、この冷媒吸込管２２ａ，２２ｂは、圧縮機１０ａ，１０ｂに吸い込まれるガス冷媒に含まれる液冷媒を分離するアキュムレータ２０に接続される。このアキュムレータ２０には、低圧ガス管７に接続される室外低圧ガス管２２が連結されている。この室外低圧ガス管２２は、３つに分岐された第１低圧分岐管２６ａ、第２低圧分岐管２６ｂ及び第３低圧分岐管２６ｃを有し、これら第１低圧分岐管２６ａ、第２低圧分岐管２６ｂ及び第３低圧分岐管２６ｃは、それぞれ上記第１〜第３室外四方弁１４ａ〜１４ｃに接続されている。   Further, refrigerant suction pipes 22a and 22b are provided on the suction sides of the compressors 10a and 10b, respectively, and the refrigerant suction pipes 22a and 22b separate liquid refrigerant contained in the gas refrigerant sucked into the compressors 10a and 10b. Connected to the accumulator 20. An outdoor low pressure gas pipe 22 connected to the low pressure gas pipe 7 is connected to the accumulator 20. The outdoor low-pressure gas pipe 22 includes a first low-pressure branch pipe 26a, a second low-pressure branch pipe 26b, and a third low-pressure branch pipe 26c that are branched into three, and the first low-pressure branch pipe 26a and the second low-pressure branch pipe 26c. The pipe 26b and the third low-pressure branch pipe 26c are connected to the first to third outdoor four-way valves 14a to 14c, respectively.

室外熱交換器１２は、室外空気と熱交換するものであり、通過する冷媒の状態に応じて、凝縮器または蒸発器として動作する。本実施形態では、並列に配置された第１室外熱交換器１２ａ、第２室外熱交換器１２ｂ及び第３室外熱交換器１２ｃを備え、熱交換容量（熱交換能力）は、第１室外熱交換器１２ａ＜第２室外熱交換器１２ｂ＜第３室外熱交換器１２ｃの順番に大きく構成されている。第１室外熱交換器１２ａ、第２室外熱交換器１２ｂ及び第３室外熱交換器１２ｃの一端側には、それぞれ第１室外液分岐管１９ａ、第２室外液分岐管１９ｂ及び第３室外液分岐管１９ｃが接続され、これら第１室外液分岐管１９ａ、第２室外液分岐管１９ｂ及び第３室外液分岐管１９ｃには、各室外熱交換器１２ａ〜１２ｃの近傍に、それぞれ第１室外側膨張弁１３ａ、第２室外側膨張弁１３ｂ及び第３室外側膨張弁１３ｃが設けられている。   The outdoor heat exchanger 12 exchanges heat with outdoor air, and operates as a condenser or an evaporator depending on the state of the refrigerant passing therethrough. In the present embodiment, the first outdoor heat exchanger 12a, the second outdoor heat exchanger 12b, and the third outdoor heat exchanger 12c arranged in parallel are provided, and the heat exchange capacity (heat exchange capacity) is the first outdoor heat. It is comprised large in order of the exchanger 12a <2nd outdoor heat exchanger 12b <3rd outdoor heat exchanger 12c. A first outdoor liquid branch pipe 19a, a second outdoor liquid branch pipe 19b, and a third outdoor liquid are respectively provided at one end sides of the first outdoor heat exchanger 12a, the second outdoor heat exchanger 12b, and the third outdoor heat exchanger 12c. A branch pipe 19c is connected to each of the first outdoor liquid branch pipe 19a, the second outdoor liquid branch pipe 19b, and the third outdoor liquid branch pipe 19c in the vicinity of the outdoor heat exchangers 12a to 12c. An outer expansion valve 13a, a second outdoor expansion valve 13b, and a third outdoor expansion valve 13c are provided.

また、第１室外液分岐管１９ａ、第２室外液分岐管１９ｂ及び第３室外液分岐管１９ｃは、１つの室外液管１９に接続される。この室外液管１９は、上記した液管９に接続される配管であり、この室外液管１９には、液冷媒を貯留するレシーバ２３と、冷房運転時に室外液管１９を流れる冷媒に過冷却を与える過冷却器２８とが設けられている。過冷却器２８は、室外液管１９を流れる液冷媒の一部を取り出し、膨張弁２８ａによって膨張気化させて冷却した冷媒によって、室外液管１９を流れる液冷媒に過冷却を与えるようになっている。過冷却に用いられて気化したガス冷媒は、アキュムレータ２０に返送される。   The first outdoor liquid branch pipe 19 a, the second outdoor liquid branch pipe 19 b, and the third outdoor liquid branch pipe 19 c are connected to one outdoor liquid pipe 19. The outdoor liquid pipe 19 is a pipe connected to the liquid pipe 9 described above. The outdoor liquid pipe 19 is supercooled by a receiver 23 that stores liquid refrigerant and a refrigerant that flows through the outdoor liquid pipe 19 during cooling operation. And a supercooler 28 for providing The subcooler 28 takes out a part of the liquid refrigerant flowing through the outdoor liquid pipe 19, and gives supercooling to the liquid refrigerant flowing through the outdoor liquid pipe 19 by the refrigerant that is expanded and vaporized by the expansion valve 28a and cooled. Yes. The gas refrigerant used for subcooling and vaporized is returned to the accumulator 20.

また、第１室外熱交換器１２ａ、第２室外熱交換器１２ｂ及び第３室外熱交換器１２ｃの他端側は、第１ガス冷媒管２５ａ、第２ガス冷媒管２５ｂ及び第３ガス冷媒管２５ｃを介して、それぞれ上記第１〜第３室外四方弁１４ａ〜１４ｃに接続されている。   The other ends of the first outdoor heat exchanger 12a, the second outdoor heat exchanger 12b, and the third outdoor heat exchanger 12c are the first gas refrigerant pipe 25a, the second gas refrigerant pipe 25b, and the third gas refrigerant pipe. 25c is connected to the first to third outdoor four-way valves 14a to 14c, respectively.

第１〜第３室外制御弁２７ａ〜２７ｃは、同一の構成を有するものであるため、第１室外制御弁２７ａについて説明する。第１室外制御弁２７ａは、第１高圧分岐管２４ａに設けられ、圧縮機１０から吐出されたガス冷媒を第１室外四方弁１４ａを通じて、第１室外熱交換器１２ａへ供給する、もしくは、供給を遮断する開閉弁である。本実施形態では、第１室外熱交換器１２ａ、第２室外熱交換器１２ｂ及び第３室外熱交換器１２ｃにそれぞれ対応して第１〜第３室外制御弁２７ａ〜２７ｃを設けているが、少なくとも熱交換容量の最も大きい第３室外熱交換器１２ｃに対応する第３高圧分岐管２４ｃに設けてあれば良い。   Since the first to third outdoor control valves 27a to 27c have the same configuration, the first outdoor control valve 27a will be described. The first outdoor control valve 27a is provided in the first high-pressure branch pipe 24a, and supplies the gas refrigerant discharged from the compressor 10 to the first outdoor heat exchanger 12a through the first outdoor four-way valve 14a. It is an on-off valve that shuts off. In the present embodiment, the first to third outdoor control valves 27a to 27c are provided corresponding to the first outdoor heat exchanger 12a, the second outdoor heat exchanger 12b, and the third outdoor heat exchanger 12c, respectively. What is necessary is just to provide in the 3rd high voltage | pressure branch pipe 24c corresponding to the 3rd outdoor heat exchanger 12c with the largest heat exchange capacity | capacitance at least.

第１〜第３室外四方弁１４ａ〜１４ｃは、同一の構成を有するものであるため、同等の符号を付して第１室外四方弁１４ａについて説明する。第１室外四方弁１４ａは、第１高圧分岐管２４ａが接続される高圧ガス管用ポート１４−１と、第１ガス冷媒管２５ａが接続される室外熱交換器側ポート１４−２と、第１低圧分岐管２６ａが接続される低圧ガス管側ポート１４−３と、ストレーナ１７ａ及びキャピラリチューブ１８ａを介して、第１低圧分岐管２６ａに接続されるバイパス管側ポート１４−４とを備えている。   Since the 1st-3rd outdoor four-way valves 14a-14c have the same composition, the same numerals are attached and the 1st outdoor four-way valve 14a is explained. The first outdoor four-way valve 14a includes a high pressure gas pipe port 14-1 to which the first high pressure branch pipe 24a is connected, an outdoor heat exchanger side port 14-2 to which the first gas refrigerant pipe 25a is connected, and a first A low pressure gas pipe side port 14-3 to which the low pressure branch pipe 26a is connected, and a bypass pipe side port 14-4 connected to the first low pressure branch pipe 26a via the strainer 17a and the capillary tube 18a are provided. .

第１室外四方弁１４ａは、上記した４つのポートを連通させることにより、冷媒の流路を形成する。具体的には、高圧ガス管用ポート１４−１と室外熱交換器側ポート１４−２とを連通させると共に、低圧ガス管側ポート１４−３とバイパス管側ポート１４−４とを連通させる。これにより、圧縮機１０の吐出側から第１高圧分岐管２４ａ、第１室外制御弁２７ａ、第１室外四方弁１４ａ及び第１ガス冷媒管２５ａを通じて、第１室外熱交換器１２ａへ冷媒が流れる高圧ガス流路が形成される。この場合、第１室外制御弁２７ａを閉じることにより、第１室外熱交換器１２ａへの冷媒の流れを遮断することができ、例えば、低外気温下の冷房運転時に、凝縮器として使用する室外熱交換器１２の熱交換容量を抑えることができ、使用しない室外熱交換器（第１室外熱交換器１２ａ）内に液冷媒が溜まることを防止できる。また、この場合、キャピラリチューブ１８ａは、第１室外四方弁１４ａを介して、両端が第１低圧分岐管２６ａに接続されることで閉ループとなる。   The first outdoor four-way valve 14a forms a refrigerant flow path by communicating the four ports described above. Specifically, the high pressure gas pipe port 14-1 and the outdoor heat exchanger side port 14-2 are communicated, and the low pressure gas pipe side port 14-3 and the bypass pipe side port 14-4 are communicated. Thereby, the refrigerant flows from the discharge side of the compressor 10 to the first outdoor heat exchanger 12a through the first high-pressure branch pipe 24a, the first outdoor control valve 27a, the first outdoor four-way valve 14a, and the first gas refrigerant pipe 25a. A high pressure gas flow path is formed. In this case, the flow of the refrigerant to the first outdoor heat exchanger 12a can be shut off by closing the first outdoor control valve 27a. For example, the outdoor used as a condenser at the time of cooling operation under a low outdoor temperature. The heat exchange capacity of the heat exchanger 12 can be suppressed, and liquid refrigerant can be prevented from accumulating in the outdoor heat exchanger (first outdoor heat exchanger 12a) that is not used. In this case, the capillary tube 18a is closed loop by connecting both ends to the first low-pressure branch pipe 26a via the first outdoor four-way valve 14a.

また、第１室外四方弁１４ａは、室外熱交換器側ポート１４−２と低圧ガス管側ポート１４−３とを連通させると共に、高圧ガス管用ポート１４−１とバイパス管側ポート１４−４とを連通させる。これにより、第１室外熱交換器１２ａから第１ガス冷媒管２５ａ、第１室外四方弁１４ａ及び第１低圧分岐管２６ａを通じて、圧縮機１０の吸込側へ冷媒が流れる低圧ガス流路が形成される。この場合、第１室外熱交換器１２ａは蒸発器として使用される。このため、第１室外制御弁２７ａが冷媒の流路から外れることにより、該第１室外制御弁２７ａを第１ガス冷媒管２５ａに設ける場合と比較して、口径の大きな室外制御弁を要することがない。また、この場合、第１高圧分岐管２４ａを流れる高圧の冷媒は、キャピラリチューブ１８ａにより減圧されて第１低圧分岐管２６ａに流入する。さらに、この構成で、第１室外制御弁２７ａを閉じることにより、キャピラリチューブ１８ａを通じて、圧縮機１０の吐出側から圧縮機１０の吸込側への冷媒の流れを遮断することができる。このため、空調運転に直接関与しない冷媒の流れを遮断できることにより、結果として空調能力の低下を抑制できる。一方で、第１室外制御弁２７ａを閉じたままとすると、この第１室外制御弁２７ａと圧縮機１０との間の高圧ガス冷媒が放冷されて液化し、この液冷媒が溜まることが想定される。従って、第１室外制御弁２７ａを閉じている期間中に、該第１室外制御弁２７ａを定期的、もしくは、不定期に所定時間（例えば１０秒）だけ開放することで、溜まった液冷媒を、キャピラリチューブ１８ａを通じて排出することができる。   The first outdoor four-way valve 14a allows the outdoor heat exchanger side port 14-2 and the low pressure gas pipe side port 14-3 to communicate with each other, and the high pressure gas pipe port 14-1 and the bypass pipe side port 14-4. To communicate. As a result, a low-pressure gas passage is formed through which the refrigerant flows from the first outdoor heat exchanger 12a to the suction side of the compressor 10 through the first gas refrigerant pipe 25a, the first outdoor four-way valve 14a, and the first low-pressure branch pipe 26a. The In this case, the first outdoor heat exchanger 12a is used as an evaporator. For this reason, when the first outdoor control valve 27a is removed from the refrigerant flow path, an outdoor control valve having a large diameter is required as compared with the case where the first outdoor control valve 27a is provided in the first gas refrigerant pipe 25a. There is no. In this case, the high-pressure refrigerant flowing through the first high-pressure branch pipe 24a is decompressed by the capillary tube 18a and flows into the first low-pressure branch pipe 26a. Further, with this configuration, by closing the first outdoor control valve 27a, the flow of the refrigerant from the discharge side of the compressor 10 to the suction side of the compressor 10 can be blocked through the capillary tube 18a. For this reason, the flow of the refrigerant that is not directly involved in the air conditioning operation can be blocked, and as a result, a decrease in the air conditioning capacity can be suppressed. On the other hand, if the first outdoor control valve 27a is kept closed, the high-pressure gas refrigerant between the first outdoor control valve 27a and the compressor 10 is allowed to cool and liquefy, and this liquid refrigerant accumulates. Is done. Accordingly, during the period in which the first outdoor control valve 27a is closed, the liquid refrigerant accumulated is released by opening the first outdoor control valve 27a regularly or irregularly for a predetermined time (for example, 10 seconds). And can be discharged through the capillary tube 18a.

室内ユニット３は、複数設けられており、各室内ユニット３ａ〜３ｄの構成は同等とされる。ここでは、室内ユニット３ａについて説明し、他の室内ユニット３ｂ〜３ｄについては説明を省略する。室内ユニット３ａは、室内空気と熱交換を行う室内熱交換器４０を備えている。室内熱交換器４０と液管９とを接続する液冷媒用分岐管９ｃには、室内側膨張弁４２が設けられている。   A plurality of indoor units 3 are provided, and the configurations of the indoor units 3a to 3d are the same. Here, the indoor unit 3a will be described, and description of the other indoor units 3b to 3d will be omitted. The indoor unit 3a includes an indoor heat exchanger 40 that exchanges heat with room air. An indoor expansion valve 42 is provided in the liquid refrigerant branch pipe 9 c that connects the indoor heat exchanger 40 and the liquid pipe 9.

また、室内ユニット３ａは、室内熱交換器４０と高圧ガス管５及び低圧ガス管７の切り換えを行う分流コントローラ４６が設けられている。分流コントローラ４６は、室内側四方弁４８を備え、この室内側四方弁４８は、高圧ガス管５の主管から分岐された高圧ガス分岐管５ｃに接続される高圧ガス管用ポート４８−１と、室内熱交換器４０側に接続される室内熱交換器側ポート４８−２と、低圧ガス管７の主管から分岐された室内側低圧ガス分岐管７ｃに接続される低圧ガス管用ポート４８−３と、第１キャピラリチューブ５７を介して、室内側低圧ガス分岐管７ｃに接続される低圧バイパス管用ポート４８−４と、を有している。   Further, the indoor unit 3a is provided with a shunt controller 46 for switching between the indoor heat exchanger 40, the high pressure gas pipe 5 and the low pressure gas pipe 7. The shunt controller 46 includes a room-side four-way valve 48, and the room-side four-way valve 48 includes a high-pressure gas pipe port 48-1 connected to the high-pressure gas branch pipe 5 c branched from the main pipe of the high-pressure gas pipe 5, An indoor heat exchanger side port 48-2 connected to the heat exchanger 40 side, a low pressure gas pipe port 48-3 connected to the indoor side low pressure gas branch pipe 7c branched from the main pipe of the low pressure gas pipe 7, A low-pressure bypass pipe port 48-4 connected to the indoor low-pressure gas branch pipe 7 c through the first capillary tube 57.

室内側四方弁４８は、暖房運転時には、高圧ガス管用ポート４８−１と室内熱交換器側ポート４８−２とを連通し、かつ、低圧ガス管用ポート４８−３と低圧バイパス管用ポート４８−４とを連通する。また、室内側四方弁４８は、後述する冷房運転時には、高圧ガス管用ポート４８−１と低圧バイパス管用ポート４８−４とを連通し、かつ、室内熱交換器側ポート４８−２と低圧ガス管用ポート４８−３とを連通する。   The indoor four-way valve 48 communicates the high-pressure gas pipe port 48-1 and the indoor heat exchanger-side port 48-2 during heating operation, and the low-pressure gas pipe port 48-3 and the low-pressure bypass pipe port 48-4. Communicate with. The indoor side four-way valve 48 communicates with the high pressure gas pipe port 48-1 and the low pressure bypass pipe port 48-4 during cooling operation, which will be described later, and the indoor heat exchanger side port 48-2 and low pressure gas pipe. It communicates with port 48-3.

室内側四方弁４８の上流側の高圧ガス分岐管５ｃには、高圧ガス分岐管用開閉弁５２が設けられている。この高圧ガス分岐管用開閉弁５２を迂回するように第２キャピラリチューブ５５が設けられている。この第２キャピラリチューブ５５の上流側の高圧ガス分岐管５ｃとの室内側低圧ガス分岐管７ｃとの間には、高圧ガス分岐管５ｃ側から室内側低圧ガス分岐管７ｃ側に向かって、第１高低圧バイパス管用開閉弁６０と第３キャピラリチューブ６２とが順に設けられる高低圧バイパス管が接続されている。また、第２キャピラリチューブ５５の下流側の高圧ガス分岐管５ｃとの室内側低圧ガス分岐管７ｃとの間には、高圧ガス分岐管５ｃ側から室内側低圧ガス分岐管７ｃ側に向かって、第２高低圧バイパス管用開閉弁６３と第４キャピラリチューブ６４とが順に設けられる高低圧バイパス管が接続されている。また、室内側四方弁４８の上流側の高圧ガス分岐管５ｃには、室内側四方弁４８と、高圧ガス分岐管用開閉弁５２との間に、該室内側四方弁４８へ冷媒を供給する、もしくは、供給を遮断する室内側制御弁６５が設けられている。この室内側制御弁６５は、上記した第１室外制御弁２７ａと同様に、冷房運転時に、第１キャピラリチューブ５７を通じて、高圧ガス分岐管５ｃ側から室内側低圧ガス分岐管７ｃ側への冷媒の流れを遮断するものである。この室内側制御弁６５により、空調運転に直接関与しない冷媒の流れを遮断できることにより、結果として空調能力の低下を抑制できる。一方で、室内側制御弁６５を閉じたままとすると、この室内側制御弁６５の下流側で高圧ガス分岐管用開閉弁５２を通じて流れる高圧ガス冷媒、もしくは、第２キャピラリチューブ５５で減圧されたガス冷媒が放冷されて液化し、この液冷媒が溜まることが想定される。従って、室内側制御弁６５を定期的、もしくは、不定期に所定時間（例えば１０秒）だけ開放することで、溜まった液冷媒を第１キャピラリチューブ５７を通じて、排出することができる。   A high-pressure gas branch pipe open / close valve 52 is provided in the high-pressure gas branch pipe 5 c upstream of the indoor side four-way valve 48. A second capillary tube 55 is provided so as to bypass the high-pressure gas branch pipe on-off valve 52. Between the high-pressure gas branch pipe 5c upstream of the second capillary tube 55 and the indoor low-pressure gas branch pipe 7c, the second high-pressure gas branch pipe 5c side toward the indoor low-pressure gas branch pipe 7c side A high / low pressure bypass pipe in which an open / close valve for 1 high / low pressure bypass pipe 60 and a third capillary tube 62 are sequentially provided is connected. Further, between the high-pressure gas branch pipe 5c on the downstream side of the second capillary tube 55 and the indoor low-pressure gas branch pipe 7c, from the high-pressure gas branch pipe 5c side to the indoor low-pressure gas branch pipe 7c side, A high / low pressure bypass pipe in which a second high / low pressure bypass pipe open / close valve 63 and a fourth capillary tube 64 are provided in order is connected. In addition, a refrigerant is supplied to the high-pressure gas branch pipe 5c upstream of the indoor-side four-way valve 48 between the indoor-side four-way valve 48 and the high-pressure gas branch pipe on-off valve 52. Or the indoor side control valve 65 which interrupts supply is provided. Similar to the first outdoor control valve 27a described above, the indoor side control valve 65 allows the refrigerant to flow from the high pressure gas branch pipe 5c side to the indoor side low pressure gas branch pipe 7c side through the first capillary tube 57 during the cooling operation. The flow is interrupted. The indoor control valve 65 can block the flow of the refrigerant that is not directly involved in the air conditioning operation, and as a result, a decrease in the air conditioning capacity can be suppressed. On the other hand, if the indoor side control valve 65 is kept closed, the high pressure gas refrigerant flowing through the high pressure gas branch pipe opening / closing valve 52 on the downstream side of the indoor side control valve 65 or the gas decompressed by the second capillary tube 55. It is assumed that the refrigerant is allowed to cool and liquefy, and this liquid refrigerant accumulates. Therefore, the accumulated liquid refrigerant can be discharged through the first capillary tube 57 by opening the indoor control valve 65 regularly or irregularly for a predetermined time (for example, 10 seconds).

次に、上記構成の冷暖房フリーマルチエアコン１００について、各運転モードに応じてその動作を説明する。本実施形態にかかる冷暖房フリーマルチエアコンは、要求される凝縮能力・蒸発能力に応じて、室外熱交換器１２の動作を適宜変更することができる。   Next, the operation of the cooling / heating free multi air conditioner 100 having the above-described configuration will be described according to each operation mode. The air conditioning free multi air conditioner according to the present embodiment can appropriately change the operation of the outdoor heat exchanger 12 according to the required condensation capacity and evaporation capacity.

［全暖房運転パターン］
次に、冬季のように、すべての室内ユニット３ａ〜３ｄにおいて暖房運転が選択されている場合の動作について、図１を用いて説明する。この場合、第１室外熱交換器１２ａ〜第３室外熱交換器１２ｃは、いずれも蒸発器として動作する。 [All heating operation pattern]
Next, the operation when the heating operation is selected in all the indoor units 3a to 3d as in winter will be described with reference to FIG. In this case, all of the first outdoor heat exchanger 12a to the third outdoor heat exchanger 12c operate as an evaporator.

圧縮機１０によって圧縮された高圧ガス冷媒は、室外高圧ガス管２１及び高圧ガス管５を通って各室内ユニット３ａ〜３ｄへと導かれる。高圧ガス冷媒のごく一部は、室外高圧ガス管２１の分岐点２３において分岐した高圧分岐管２４、及び、更に分岐した第１高圧分岐管２４ａ、第２高圧分岐管２４ｂ、第３高圧分岐管２４ｃを通じて、それぞれ第１〜第３室外四方弁１４ａ〜１４ｃに向かって流れる。この場合、第１〜第３室外四方弁１４ａ〜１４ｃでは、高圧ガス管用ポート１４−１とバイパス管側ポート１４−４とが連通され、また、室外熱交換器側ポート１４−２と低圧ガス管側ポート１４−３とが連通されている。また、第１高圧分岐管２４ａ、第２高圧分岐管２４ｂ、第３高圧分岐管２４ｃにそれぞれ設けられた第１室外制御弁２７ａ、第２室外制御弁２７ｂ及び第３室外制御弁２７ｃは、いずれも閉弁されている。   The high-pressure gas refrigerant compressed by the compressor 10 is guided to the indoor units 3 a to 3 d through the outdoor high-pressure gas pipe 21 and the high-pressure gas pipe 5. A small part of the high-pressure gas refrigerant is a high-pressure branch pipe 24 branched at a branch point 23 of the outdoor high-pressure gas pipe 21, and further branched first high-pressure branch pipe 24a, second high-pressure branch pipe 24b, and third high-pressure branch pipe. It flows toward the 1st-3rd outdoor four-way valves 14a-14c through 24c, respectively. In this case, in the first to third outdoor four-way valves 14a to 14c, the high pressure gas pipe port 14-1 and the bypass pipe side port 14-4 are communicated, and the outdoor heat exchanger side port 14-2 and the low pressure gas. The tube side port 14-3 is in communication. Further, the first outdoor control valve 27a, the second outdoor control valve 27b, and the third outdoor control valve 27c provided in the first high pressure branch pipe 24a, the second high pressure branch pipe 24b, and the third high pressure branch pipe 24c, respectively, Is also closed.

したがって、第１高圧分岐管２４ａ、第２高圧分岐管２４ｂ及び第３高圧分岐管２４ｃに流入した冷媒は、第１室外制御弁２７ａ、第２室外制御弁２７ｂ及び第３室外制御弁２７ｃによって、第１室外四方弁１４ａ、第２室外四方弁１４ｂ及び第３室外四方弁１４ｃへの流入が遮断される、このため、第１〜第３室外四方弁１４ａ〜１４ｃにそれぞれ流入した高圧ガス冷媒が、バイパス管側ポート１４−４を通って、キャピラリチューブ１８ａ〜１８ｃで減圧された後、第１低圧分岐管２６ａ〜第３低圧分岐管２６ｃに流れ込むことが防止される。   Accordingly, the refrigerant flowing into the first high-pressure branch pipe 24a, the second high-pressure branch pipe 24b, and the third high-pressure branch pipe 24c is caused by the first outdoor control valve 27a, the second outdoor control valve 27b, and the third outdoor control valve 27c. Inflow to the first outdoor four-way valve 14a, the second outdoor four-way valve 14b, and the third outdoor four-way valve 14c is blocked. Therefore, the high-pressure gas refrigerant flowing into the first to third outdoor four-way valves 14a to 14c respectively. Then, after being depressurized by the capillary tubes 18a to 18c through the bypass pipe side port 14-4, it is prevented from flowing into the first low pressure branch pipe 26a to the third low pressure branch pipe 26c.

高圧ガス管５によって室内ユニット３ａ〜３ｄへと導かれた高圧ガス冷媒は、各高圧ガス分岐管５ｃを通過して、各分流コントローラ４６へと流れ込む。分流コントローラ４６の室内側四方弁４８は、高圧ガス管用ポート４８−１と室内熱交換器側ポート４８−２とを連通し、かつ、低圧ガス管用ポート４８−３と低圧バイパス管用ポート４８−４とを連通している。また、この運転パターンでは、高圧ガス分岐管用開閉弁５２及び室内側制御弁６５は開かれ、第１高低圧バイパス管用開閉弁６０及び第２高低圧バイパス管用開閉弁６３は閉じられている。   The high-pressure gas refrigerant guided to the indoor units 3 a to 3 d by the high-pressure gas pipe 5 passes through the high-pressure gas branch pipes 5 c and flows into the branch flow controllers 46. The indoor side four-way valve 48 of the shunt controller 46 communicates the high pressure gas pipe port 48-1 and the indoor heat exchanger side port 48-2, and the low pressure gas pipe port 48-3 and the low pressure bypass pipe port 48-4. And communicate with. In this operation pattern, the high-pressure gas branch pipe on-off valve 52 and the indoor control valve 65 are opened, and the first high-low pressure bypass pipe on-off valve 60 and the second high-low pressure bypass pipe on-off valve 63 are closed.

したがって、高圧ガス冷媒は、室内側四方弁４８を通って、室内熱交換器４０へと導かれ、この室内熱交換器４０で凝縮・液化することによって室内空気に熱を与えて暖房を行う。室内熱交換器４０で液化した高圧液冷媒は、液冷媒用分岐管９ｃを通って、主管である液管９へと合流する。この高圧液冷媒は、液管９によって室外ユニット１へと導かれ、室外液管１９を流通した後に、第１室外液分岐管１９ａ、第２室外液分岐管１９ｂ及び第３室外液分岐管１９ｃにそれぞれ分岐して流れ、第１室外側膨張弁１３ａ、第２室外側膨張弁１３ｂ及び第３室外側膨張弁１３ｃにて減圧されて低圧液冷媒となる。そして、この低圧液冷媒は、第１室外熱交換器１２ａ、第２室外熱交換器１２ｂ及び第３室外熱交換器１２ｃにおいて、外気から熱を奪うことにより蒸発して低圧ガス冷媒とされる。低圧ガス冷媒は、それぞれ、第１〜第３ガス冷媒管２５ａ〜２５ｃを介して、上記第１〜第３室外四方弁１４ａ〜１４ｃへと導かれた後、第１〜第３低圧分岐管２６ａ〜２６ｃを介して、室外低圧ガス管２２で合流する。そして、この低圧ガス冷媒は、再び冷媒吸込管２２ａ，２２ｂに分岐した後、圧縮機１０ａ，１０ｂへ戻される。   Therefore, the high-pressure gas refrigerant is led to the indoor heat exchanger 40 through the indoor side four-way valve 48, and is condensed and liquefied by the indoor heat exchanger 40 to give heat to the indoor air to perform heating. The high-pressure liquid refrigerant liquefied by the indoor heat exchanger 40 passes through the liquid refrigerant branch pipe 9c and joins the liquid pipe 9 as the main pipe. The high-pressure liquid refrigerant is guided to the outdoor unit 1 by the liquid pipe 9 and after flowing through the outdoor liquid pipe 19, the first outdoor liquid branch pipe 19a, the second outdoor liquid branch pipe 19b, and the third outdoor liquid branch pipe 19c. Respectively, and is decompressed by the first outdoor expansion valve 13a, the second outdoor expansion valve 13b, and the third outdoor expansion valve 13c to become a low-pressure liquid refrigerant. The low-pressure liquid refrigerant evaporates by taking heat from the outside air into the low-pressure gas refrigerant in the first outdoor heat exchanger 12a, the second outdoor heat exchanger 12b, and the third outdoor heat exchanger 12c. The low-pressure gas refrigerant is led to the first to third outdoor four-way valves 14a to 14c via the first to third gas refrigerant pipes 25a to 25c, respectively, and then the first to third low-pressure branch pipes 26a. It joins with the outdoor low-pressure gas pipe 22 via -26c. The low-pressure gas refrigerant is branched again into the refrigerant suction pipes 22a and 22b, and then returned to the compressors 10a and 10b.

このように、すべての室内ユニット３ａ〜３ｄで暖房運転をする場合には、第１室外制御弁２７ａ、第２室外制御弁２７ｂ及び第３室外制御弁２７ｃを閉じるため、第１室外四方弁１４ａ、第２室外四方弁１４ｂ及び第３室外四方弁１４ｃへの流入が遮断される、このため、第１〜第３室外四方弁１４ａ〜１４ｃにそれぞれ流入した高圧ガス冷媒が、バイパス管側ポート１４−４を通って、キャピラリチューブ１８ａ〜１８ｃで減圧された後、第１低圧分岐管２６ａ〜第３低圧分岐管２６ｃに流れ込むことが防止される。一方で、第１室外制御弁２７ａを閉じたままとすると、この第１室外制御弁２７ａと圧縮機１０との間の高圧ガス冷媒が放冷されて液化し、この液冷媒が溜まることが想定される。従って、第１室外制御弁２７ａを定期的、もしくは、不定期に所定時間（例えば１０秒）だけ開放することで、溜まった液冷媒をキャピラリチューブ１８ａを通じて、排出することができる。   Thus, when heating operation is performed in all the indoor units 3a to 3d, the first outdoor four-way valve 14a is closed in order to close the first outdoor control valve 27a, the second outdoor control valve 27b, and the third outdoor control valve 27c. Therefore, the inflow to the second outdoor four-way valve 14b and the third outdoor four-way valve 14c is blocked. Therefore, the high-pressure gas refrigerant that has flowed into the first to third outdoor four-way valves 14a to 14c, respectively, 4 is prevented from flowing into the first low-pressure branch pipe 26a to the third low-pressure branch pipe 26c after being depressurized by the capillary tubes 18a to 18c. On the other hand, if the first outdoor control valve 27a is kept closed, the high-pressure gas refrigerant between the first outdoor control valve 27a and the compressor 10 is allowed to cool and liquefy, and this liquid refrigerant accumulates. Is done. Therefore, the accumulated liquid refrigerant can be discharged through the capillary tube 18a by opening the first outdoor control valve 27a regularly or irregularly for a predetermined time (for example, 10 seconds).

［冷房主体運転パターン（低外気温）］
図２は、低外気温下における冷房主体運転の運転パターンを示した概略構成図である。この運転パターンは、外気温が所定温度（例えば２０℃以下）の環境下においても、例えばコンピュータルームのように冷房主体運転を行う場合を示している。 [Cooling operation pattern (low outside temperature)]
FIG. 2 is a schematic configuration diagram showing an operation pattern of the cooling main operation under a low outside air temperature. This operation pattern shows a case where the cooling main operation is performed as in a computer room, for example, even in an environment where the outside air temperature is a predetermined temperature (for example, 20 ° C. or less).

この図２において、室内ユニット３ａは暖房運転が選択され、室内ユニット３ｂ，３ｃ，３ｄは冷房運転が選択されている。この運転パターンでは、夏季のように要求冷房能力が大きくなく、したがって要求される凝縮能力が比較的小さい（例えば能力の５０％）ので、第２室外熱交換器１２ｂ及び第３室外熱交換器１２ｃは停止されている。   In FIG. 2, heating operation is selected for the indoor unit 3a, and cooling operation is selected for the indoor units 3b, 3c, and 3d. In this operation pattern, the required cooling capacity is not large as in summer, and therefore the required condensation capacity is relatively small (for example, 50% of the capacity), so the second outdoor heat exchanger 12b and the third outdoor heat exchanger 12c. Has been stopped.

圧縮機１０によって圧縮された高圧ガス冷媒は、室外高圧ガス管２１及び高圧ガス管５を通って各室内ユニット３ａ〜３ｄへと導かれる。高圧ガス冷媒の一部は、室外高圧ガス管２１の分岐点２３において分岐した高圧分岐管２４、及び、更に分岐した第１高圧分岐管２４ａ、第２高圧分岐管２４ｂ、第３高圧分岐管２４ｃを通じて、それぞれ第１〜第３室外四方弁１４ａ〜１４ｃに向かって流れる。この場合、第１〜第３室外四方弁１４ａ〜１４ｃでは、高圧ガス管用ポート１４−１と室外熱交換器側ポート１４−２とが連通され、また、低圧ガス管側ポート１４−３とバイパス管側ポート１４−４とが連通されている。また、第１室外制御弁２７ａは開かれ、第２室外制御弁２７ｂ及び第３室外制御弁２７ｃはいずれも閉じられている。これにより、圧縮機１０から第２室外熱交換器１２ｂ及び第３室外熱交換器１２ｃへの高圧ガス冷媒の流入が防止され、第２室外熱交換器１２ｂ及び第３室外熱交換器１２ｃは停止される。   The high-pressure gas refrigerant compressed by the compressor 10 is guided to the indoor units 3 a to 3 d through the outdoor high-pressure gas pipe 21 and the high-pressure gas pipe 5. Part of the high-pressure gas refrigerant is a high-pressure branch pipe 24 branched at a branch point 23 of the outdoor high-pressure gas pipe 21, and further branched first high-pressure branch pipe 24a, second high-pressure branch pipe 24b, and third high-pressure branch pipe 24c. And flows toward the first to third outdoor four-way valves 14a to 14c, respectively. In this case, in the first to third outdoor four-way valves 14a to 14c, the high pressure gas pipe port 14-1 and the outdoor heat exchanger side port 14-2 are communicated with each other, and the low pressure gas pipe side port 14-3 is bypassed. The tube side port 14-4 is communicated. Further, the first outdoor control valve 27a is opened, and the second outdoor control valve 27b and the third outdoor control valve 27c are both closed. Thereby, inflow of the high-pressure gas refrigerant from the compressor 10 to the second outdoor heat exchanger 12b and the third outdoor heat exchanger 12c is prevented, and the second outdoor heat exchanger 12b and the third outdoor heat exchanger 12c are stopped. Is done.

第１室外制御弁２７ａを通じて、第１室外四方弁１４ａに流入した高圧ガス冷媒は、第１ガス冷媒管２５ａを介して、第１室外熱交換器１２ａに流入し、この第１室外熱交換器１２ａで凝縮・液化することによって室外空気に熱を排出する。この液冷媒は、第１室外側膨張弁１３ａにて減圧されて低圧液冷媒となる。そして、この低圧液冷媒は、過冷却器２８にて過冷却された後、室外液管１９及び液管９を通じて室内ユニット３ａ〜３ｄに送られる。   The high-pressure gas refrigerant that has flowed into the first outdoor four-way valve 14a through the first outdoor control valve 27a flows into the first outdoor heat exchanger 12a through the first gas refrigerant pipe 25a, and this first outdoor heat exchanger. Heat is discharged to outdoor air by condensing and liquefying at 12a. This liquid refrigerant is decompressed by the first outdoor expansion valve 13a to become a low-pressure liquid refrigerant. The low-pressure liquid refrigerant is supercooled by the supercooler 28 and then sent to the indoor units 3 a to 3 d through the outdoor liquid pipe 19 and the liquid pipe 9.

室内ユニット３ａは、室内側四方弁４８を切り換えることによって、冷房運転から暖房運転へと切り換えられる。つまり、室内側四方弁４８は、暖房運転時には、高圧ガス管用ポート４８−１と室内熱交換器側ポート４８−２とを連通し、かつ、低圧ガス管用ポート４８−３と低圧バイパス管用ポート４８−４とを連通するように切り換えられる。   The indoor unit 3a is switched from the cooling operation to the heating operation by switching the indoor side four-way valve 48. That is, the indoor side four-way valve 48 communicates the high pressure gas pipe port 48-1 and the indoor heat exchanger side port 48-2 during heating operation, and the low pressure gas pipe port 48-3 and the low pressure bypass pipe port 48. -4 to communicate with each other.

一方、室内ユニット３ｂ，３ｃ，３ｄは冷房運転であるため、室内側四方弁４８は、高圧ガス管用ポート４８−１と低圧バイパス管用ポート４８−４とを連通し、かつ、室内熱交換器側ポート４８−２と低圧ガス管用ポート４８−３とを連通させる。この構成では、暖房運転する室内ユニット３ａでは、高圧ガス分岐管用開閉弁５２及び室内側制御弁６５は開かれ、第１高低圧バイパス管用開閉弁６０及び第２高低圧バイパス管用開閉弁６３は閉じられている。また、冷房運転する室内ユニット３ｂ，３ｃ，３ｄでは、高圧ガス分岐管用開閉弁５２、室内側制御弁６５、第１高低圧バイパス管用開閉弁６０及び第２高低圧バイパス管用開閉弁６３はいずれも閉じられている。   On the other hand, since the indoor units 3b, 3c, and 3d are in the cooling operation, the indoor four-way valve 48 communicates with the high-pressure gas pipe port 48-1 and the low-pressure bypass pipe port 48-4 and is on the indoor heat exchanger side. The port 48-2 communicates with the low-pressure gas pipe port 48-3. In this configuration, in the indoor unit 3a that performs the heating operation, the high-pressure gas branch pipe on-off valve 52 and the indoor side control valve 65 are opened, and the first high-low pressure bypass pipe on-off valve 60 and the second high-low pressure bypass pipe on-off valve 63 are closed. It has been. In the indoor units 3b, 3c, and 3d that perform the cooling operation, the high-pressure gas branch pipe opening / closing valve 52, the indoor side control valve 65, the first high / low pressure bypass pipe opening / closing valve 60, and the second high / low pressure bypass pipe opening / closing valve 63 are all. Closed.

したがって、高圧ガス冷媒は、室内ユニット３ａの室内側四方弁４８を通って、室内熱交換器４０へと導かれ、この室内熱交換器４０で凝縮・液化することによって室内空気に熱を与えて暖房を行う。室内熱交換器４０で液化した高圧液冷媒は、液冷媒用分岐管９ｃを通って、主管である液管９へと合流し、この液管９で室外ユニット１から流れた液冷媒と合流する。   Therefore, the high-pressure gas refrigerant passes through the indoor side four-way valve 48 of the indoor unit 3a, is led to the indoor heat exchanger 40, and is condensed and liquefied by the indoor heat exchanger 40 to give heat to the indoor air. Heat up. The high-pressure liquid refrigerant liquefied by the indoor heat exchanger 40 passes through the liquid refrigerant branch pipe 9c and merges with the liquid pipe 9 as the main pipe, and merges with the liquid refrigerant flowing from the outdoor unit 1 through the liquid pipe 9. .

この液冷媒は、液冷媒用分岐管９ｃを通じて、各室内ユニット３ｂ〜３ｄに流入して室内熱交換器４０へと導かれ、この室内熱交換器４０で蒸発することで室内空気の冷房をする。室内熱交換器４０で蒸発した低温のガス冷媒は、室内側四方弁４８を通って室内側低圧ガス分岐管７ｃに流れ込み、低圧ガス管７で合流した後、室外低圧ガス管２２、冷媒吸込管２２ａ，２２ｂを通じて、圧縮機１０ａ，１０ｂへ戻される。一方で、冷房運転時に、各室内ユニット３ｂ〜３ｄの室内側制御弁６５を閉じたままとすると、この室内側制御弁６５の下流側で高圧ガス分岐管用開閉弁５２を通じて流れる高圧ガス冷媒、もしくは、第２キャピラリチューブ５５で減圧されたガス冷媒が放冷されて液化し、この液冷媒が溜まることが想定される。従って、室内側制御弁６５を定期的、もしくは、不定期に所定時間（例えば１０秒）だけ開放することで、溜まった液冷媒を第１キャピラリチューブ５７を通じて、排出することができる。   The liquid refrigerant flows into the indoor units 3b to 3d through the liquid refrigerant branch pipe 9c, is guided to the indoor heat exchanger 40, and evaporates in the indoor heat exchanger 40 to cool the indoor air. . The low-temperature gas refrigerant evaporated in the indoor heat exchanger 40 flows into the indoor-side low-pressure gas branch pipe 7c through the indoor-side four-way valve 48, merges in the low-pressure gas pipe 7, and then the outdoor low-pressure gas pipe 22 and the refrigerant suction pipe. It returns to compressor 10a, 10b through 22a, 22b. On the other hand, if the indoor side control valve 65 of each indoor unit 3b-3d is kept closed during the cooling operation, the high pressure gas refrigerant flowing through the high pressure gas branch pipe opening / closing valve 52 on the downstream side of the indoor side control valve 65, or It is assumed that the gas refrigerant decompressed by the second capillary tube 55 is cooled and liquefied, and this liquid refrigerant accumulates. Therefore, the accumulated liquid refrigerant can be discharged through the first capillary tube 57 by opening the indoor control valve 65 regularly or irregularly for a predetermined time (for example, 10 seconds).

この構成では、圧縮機１０から第１〜第３室外四方弁１４ａ〜１４ｃへの流れを制御する第１〜第３室外制御弁２７ａ〜２７ｃを備えたため、この第１〜第３室外制御弁２７ａ〜２７ｃを閉じることにより、該第１〜第３室外制御弁２７ａ〜２７ｃに対応する第１〜第３室外熱交換器１２ａ〜１２ｃに冷媒が流れなくなる。このため、例えば、低外気温下の冷房運転時に、凝縮器として使用する室外熱交換器の容量を抑えることができ、使用しない第２室外熱交換器１２ｂ及び第３室外熱交換器１２ｃ内に液冷媒が溜まることを防止できる。また、第１〜第３室外制御弁２７ａ〜２７ｃを、第１〜第３室外四方弁１４ａ〜１４ｃと圧縮機１０の吐出側との間に配置したことにより、第１〜第３室外制御弁２７ａ〜２７ｃが冷媒の流路から外れることにより、該第１〜第３室外制御弁２７ａ〜２７ｃを第１〜第３ガス冷媒管２５ａ〜２５ｃに設ける場合と比較して、口径の大きな室外制御弁を要することがない。   In this configuration, since the first to third outdoor control valves 27a to 27c for controlling the flow from the compressor 10 to the first to third outdoor four-way valves 14a to 14c are provided, the first to third outdoor control valves 27a are provided. By closing ~ 27c, the refrigerant does not flow to the first to third outdoor heat exchangers 12a to 12c corresponding to the first to third outdoor control valves 27a to 27c. For this reason, the capacity | capacitance of the outdoor heat exchanger used as a condenser can be restrained, for example at the time of air_conditionaing | cooling operation under low outdoor temperature, and in the 2nd outdoor heat exchanger 12b and the 3rd outdoor heat exchanger 12c which are not used. It is possible to prevent liquid refrigerant from accumulating. Further, the first to third outdoor control valves 27a to 27c are arranged between the first to third outdoor four-way valves 14a to 14c and the discharge side of the compressor 10, so that the first to third outdoor control valves are arranged. When the first to third outdoor control valves 27a to 27c are provided in the first to third gas refrigerant pipes 25a to 25c by the separation of the refrigerant flow paths 27a to 27c, the outdoor control having a large diameter is performed. There is no need for a valve.

以上、本発明の一実施形態を説明したが、本実施形態は、例として提示したものであり、発明の範囲を限定することは意図していない。本実施形態は、その他の様々な形態で実施されることが可能であり、発明の要旨を逸脱しない範囲で、種々の省略、置き換え、変更を行うことができる。本実施形態やその変形は、発明の範囲や要旨に含まれると同様に、特許請求の範囲に記載された発明とその均等の範囲に含まれるものである。上記した実施形態では、室外熱交換器１２を３台としたが、その台数はこれに限定されず、要求される能力に応じて適宜変更される。室内ユニット３の数も適用対象に応じて適宜変更される。また、圧縮機１０を２台としたが、圧縮機台数はこれに限定されず、要求される能力に応じて適宜変更される。   Although one embodiment of the present invention has been described above, this embodiment is presented as an example and is not intended to limit the scope of the invention. The present embodiment can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. This embodiment and its modifications are included in the scope of the present invention and the gist thereof, and are also included in the invention described in the claims and the equivalents thereof. In the above-described embodiment, the number of outdoor heat exchangers 12 is three, but the number is not limited to this, and may be changed as appropriate according to the required capacity. The number of indoor units 3 is also appropriately changed according to the application target. Moreover, although the number of the compressors 10 is two, the number of compressors is not limited to this, and may be changed as appropriate according to the required capacity.

１ 室外ユニット（室外機）
３，３ａ，３ｂ，３ｃ，３ｄ 室内ユニット（室内機）
５ 高圧ガス管
７ 低圧ガス管
９ 液管
１０，１０ａ，１０ｂ 圧縮機
１２ 室外熱交換器
１２ａ 第１室外熱交換器
１２ｂ 第２室外熱交換器
１２ｃ 第３室外熱交換器
１４ａ 第１室外四方弁
１４ｂ 第２室外四方弁
１４ｃ 第３室外四方弁
１８ａ キャピラリチューブ
２４ａ 第１高圧分岐管
２４ｂ 第２高圧分岐管
２４ｃ 第３高圧分岐管
２５ａ 第１ガス冷媒管
２５ｂ 第２ガス冷媒管
２５ｃ 第３ガス冷媒管
２６ａ 第１低圧分岐管
２６ｂ 第２低圧分岐管
２６ｃ 第３低圧分岐管
２７ａ 第１室外制御弁
２７ｂ 第２室外制御弁
２７ｃ 第３室外制御弁
４０ 室内熱交換器
４２ 室内側膨張弁
４６ 分流コントローラ
４８ 室内側四方弁
５７ 第１キャピラリチューブ
６５ 室内側制御弁
１００ 冷暖房フリーマルチエアコン（空気調和装置） 1 Outdoor unit (outdoor unit)
3, 3a, 3b, 3c, 3d Indoor unit (indoor unit)
5 High-pressure gas pipe 7 Low-pressure gas pipe 9 Liquid pipe 10, 10a, 10b Compressor 12 Outdoor heat exchanger 12a First outdoor heat exchanger 12b Second outdoor heat exchanger 12c Third outdoor heat exchanger 14a First outdoor four-way valve 14b Second outdoor four-way valve 14c Third outdoor four-way valve 18a Capillary tube 24a First high-pressure branch pipe 24b Second high-pressure branch pipe 24c Third high-pressure branch pipe 25a First gas refrigerant pipe 25b Second gas refrigerant pipe 25c Third gas refrigerant Pipe 26a First low-pressure branch pipe 26b Second low-pressure branch pipe 26c Third low-pressure branch pipe 27a First outdoor control valve 27b Second outdoor control valve 27c Third outdoor control valve 40 Indoor heat exchanger 42 Indoor expansion valve 46 Shunt controller 48 indoor-side four-way valve 57 first capillary tube 65 indoor-side control valve 100 air-conditioning-free multi air conditioner (air conditioner)

Claims (4)

圧縮機および室外熱交換器を有する室外機と、室内熱交換器を有する複数台の室内機とを備え、前記室外機と前記室内機とが高圧ガス管、低圧ガス管、および液管によって接続され、前記室内機を独立して冷房運転または暖房運転可能とした空気調和装置であって、
前記室外機は、前記高圧ガス管に吐出側が連なり、前記低圧ガス管に吸込側が連なる圧縮機と、
前記液管に並列に連なる複数の室外熱交換器と、
前記圧縮機とそれぞれの前記室外熱交換器との間に、前記圧縮機の吐出側から前記室外熱交換器へと向かう高圧ガス流路と、前記室外熱交換器から前記圧縮機の吸込側へと向かう低圧ガス流路とをそれぞれ選択的に切り換える複数の室外四方弁と、
前記室外四方弁の低圧ガス流路が選択された場合に、前記圧縮機の吐出側と連通する前記室外四方弁のポートに一端が接続され、他端が前記圧縮機の吸込側に連なる複数のキャピラリチューブと、
少なくとも前記室外四方弁の１つと前記圧縮機の吐出側との間に配置されて、該圧縮機から前記室外四方弁への流れを制御する室外制御弁と、を備えたことを特徴とする空気調和装置。 An outdoor unit having a compressor and an outdoor heat exchanger, and a plurality of indoor units having an indoor heat exchanger, the outdoor unit and the indoor unit being connected by a high pressure gas pipe, a low pressure gas pipe, and a liquid pipe And an air conditioner capable of independently cooling or heating the indoor unit,
The outdoor unit is connected to the high-pressure gas pipe at the discharge side, and the low-pressure gas pipe is connected to the suction side at the compressor,
A plurality of outdoor heat exchangers connected in parallel to the liquid pipe;
A high-pressure gas flow path from the compressor discharge side to the outdoor heat exchanger between the compressor and each of the outdoor heat exchangers, and from the outdoor heat exchanger to the compressor suction side A plurality of outdoor four-way valves that selectively switch each of the low-pressure gas flow paths toward the
When the low-pressure gas flow path of the outdoor four-way valve is selected, a plurality of ports are connected at one end to the port of the outdoor four-way valve that communicates with the discharge side of the compressor and the other end communicates with the suction side of the compressor. A capillary tube;
An outdoor control valve that is disposed between at least one of the outdoor four-way valves and a discharge side of the compressor, and controls a flow from the compressor to the outdoor four-way valve. Harmony device. 前記室外熱交換器は、熱交換容量がそれぞれ異なる構成とし、
前記室外制御弁は、少なくとも前記熱交換容量が最も大きな前記室外熱交換器に対応する前記室外四方弁と前記圧縮機の吐出側との間に配置されることを特徴とする請求項１に記載の空気調和装置。 The outdoor heat exchanger has a different heat exchange capacity,
The said outdoor control valve is arrange | positioned between the said outdoor four-way valve corresponding to the said outdoor heat exchanger with the largest said heat exchange capacity | capacitance, and the discharge side of the said compressor. Air conditioner. 前記室外制御弁は、前記室外四方弁と前記圧縮機の吐出側との間にそれぞれ配置されることを特徴とする請求項１または２に記載の空気調和装置。   The air conditioner according to claim 1 or 2, wherein the outdoor control valve is disposed between the outdoor four-way valve and a discharge side of the compressor. 前記室外四方弁の低圧ガス流路が選択された場合、
前記室外制御弁を閉じると共に、定期的もしくは不定期に、該室外制御弁を所定時間だけ開放することを特徴とする請求項１から３のいずれか一項に記載の空気調和装置。 When the low-pressure gas flow path of the outdoor four-way valve is selected,
The air conditioner according to any one of claims 1 to 3, wherein the outdoor control valve is closed and the outdoor control valve is opened only for a predetermined time regularly or irregularly.
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