JP2015222157A

JP2015222157A - Air conditioning device

Info

Publication number: JP2015222157A
Application number: JP2014107186A
Authority: JP
Inventors: 松永　隆廣; Takahiro Matsunaga; 隆廣松永; 秀哉田村; Hideya Tamura; 智昭巳野; Tomoaki Mino; 廣太郎戸矢; Kotaro Toya; 康弘岡; Yasuhiro Oka; 佐藤　正和; Masakazu Sato; 正和佐藤; 高橋　俊裕; Toshihiro Takahashi; 俊裕高橋
Original assignee: Fujitsu General Ltd
Current assignee: Fujitsu General Ltd
Priority date: 2014-05-23
Filing date: 2014-05-23
Publication date: 2015-12-10

Abstract

PROBLEM TO BE SOLVED: To provide an air conditioning device capable of preventing frequent interruption of a heating operation while preventing short-cut of a refrigerant.SOLUTION: When an air conditioning device 1 implements a heating operation, a CPU 210 switches a first four-way valve 22a to states indicated by a solid line to communicate a port a and a port d of the first four-way valve 22a, or to communicate a port b and a port c. Further the CPU 210 switches a second four-way valve 22b to states indicated by a solid line to communicate a port e and a port h of the second four-way valve 22b or to communicate a port f and a port g. Thus a first outdoor heat exchanger 23a and a second outdoor heat exchanger 23b are functioned as evaporators, and indoor heat exchangers 51a-51c are functioned as condensers. The CPU 210 opens an electromagnetic opening/closing valve 28.

Description

本発明は、複数の流路切替手段と複数の室外熱交換器とを備えた室外機を有する空気調和装置に関する。 The present invention relates to an air conditioner having an outdoor unit provided with a plurality of flow path switching means and a plurality of outdoor heat exchangers.

従来、複数の流路切替手段（例えば、四方弁）と複数の室外熱交換器とを備えた室外機を有する空気調和装置が提案されている。このような空気調和装置として、例えば、図４に示すように、圧縮機３１０と、二つの四方弁３２０ａ、３２０ｂと、二つの室外熱交換器３３０ａ、３３０ｂと、電磁弁３５０と、逆止弁３４０とを有する室外機と、膨張弁４２０と、室内熱交換器４３０とを有する室内機とで構成されるものがある（特許文献１参照）。 Conventionally, an air conditioner having an outdoor unit provided with a plurality of flow path switching means (for example, a four-way valve) and a plurality of outdoor heat exchangers has been proposed. As such an air conditioner, for example, as shown in FIG. 4, a compressor 310, two four-way valves 320a and 320b, two outdoor heat exchangers 330a and 330b, an electromagnetic valve 350, and a check valve Some include an outdoor unit having 340, an expansion valve 420, and an indoor unit having an indoor heat exchanger 430 (see Patent Document 1).

電磁弁３５０は、室外熱交換器３３０ｂと膨張弁４１０の間を接続する配管に設けられている。逆止弁３４０は、四方弁３２０ａと室内熱交換器４２０の間を接続する配管と、四方弁３２０ｂとの間を接続する配管の途中に設けられている。圧縮機３１０の吐出口より繋がる配管には第１の分岐点３６０が、四方弁３２０ａ、３２０ｂおよび室外熱交換器３３０ａ、３３０ｂの並列回路から膨張弁４１０に繋がる配管には第２の分岐点３７０が、室内熱交換器４２０から四方弁３２０ａ、３２０ｂに繋がる配管には第３の分岐点３８０が、分岐点３８０から四方弁３２０ｂを経て圧縮機３１０の吸入口に繋がる配管には第４の分岐点３９０が、それぞれ設けられている。 The electromagnetic valve 350 is provided in a pipe connecting the outdoor heat exchanger 330b and the expansion valve 410. The check valve 340 is provided in the middle of a pipe connecting the four-way valve 320a and the indoor heat exchanger 420 and a pipe connecting the four-way valve 320b. The first branch point 360 is connected to the pipe connected from the discharge port of the compressor 310, and the second branch point 370 is connected to the pipe connected to the expansion valve 410 from the parallel circuit of the four-way valves 320a and 320b and the outdoor heat exchangers 330a and 330b. However, the third branch point 380 is connected to the pipe connecting the indoor heat exchanger 420 to the four-way valves 320a and 320b, and the fourth branch is connected to the pipe connecting the branch point 380 through the four-way valve 320b to the suction port of the compressor 310. Each point 390 is provided.

上述した空気調和装置では、冷媒を流す室外熱交換器の枚数を制御することで、低負荷運転時に室外熱交換器の容量制御を行える。例えば、室外機に接続されている室内機の空調負荷が小さくかつ外気温度が高い状態における暖房運転では、室外熱交換器３３０ａ、３３０ｂにおける蒸発能力が過剰となる場合がある。また、室内機の空調負荷が小さくかつ外気温度が低い状態における冷房運転では、室外熱交換器３３０ａ、３３０ｂにおける凝縮能力が過剰となる場合がある。これらの場合は、開閉弁３５０を閉とすることで、室外熱交換器３３０ｂに冷媒が流れないようにすることで、蒸発能力あるいは凝縮能力を低減する。 In the above-described air conditioner, the capacity of the outdoor heat exchanger can be controlled during low-load operation by controlling the number of outdoor heat exchangers through which the refrigerant flows. For example, in the heating operation in a state where the air conditioning load of the indoor unit connected to the outdoor unit is small and the outside air temperature is high, the evaporation capacity in the outdoor heat exchangers 330a and 330b may be excessive. Moreover, in the cooling operation in a state where the air conditioning load of the indoor unit is small and the outside air temperature is low, the condensation capacity in the outdoor heat exchangers 330a and 330b may become excessive. In these cases, the on / off valve 350 is closed to prevent the refrigerant from flowing into the outdoor heat exchanger 330b, thereby reducing the evaporation capacity or the condensation capacity.

一方、室外熱交換器３３０ａ、３３０ｂで機能を異ならせる、例えば、室外熱交換器３３０ａが凝縮器として機能するよう四方弁３２０ａを切り替え、室外熱交換器３３０ｂが蒸発器として機能するよう四方弁３２０ｂ切り替えて、空気調和装置を運転する場合がある。例えば、低外気温度（０℃以下）で空気調和装置を起動するときは、冷媒寝込み（圧縮機３１０の冷凍機油に冷媒が溶解した状態）を解消するために、圧縮機３１０を所定の回転数で駆動して圧縮機３１０が早く暖まるよう制御する。このとき、圧縮機３１０内部の圧力、つまり、圧縮機３１０の吐出圧力（高圧）が上昇することで冷媒寝込みが発生する虞がある。また、空気調和装置の起動時は、圧縮機３１０から冷媒とともに冷媒回路に吐出される冷凍機油量に対して圧縮機３１０に吸入される（冷媒回路から圧縮機３１０に戻ってくる）冷凍機油量が少ないため、圧縮機３１０で冷凍機油が不足して潤滑不良を招く虞がある。 On the other hand, the outdoor heat exchangers 330a and 330b have different functions. For example, the four-way valve 320a is switched so that the outdoor heat exchanger 330a functions as a condenser, and the four-way valve 320b so that the outdoor heat exchanger 330b functions as an evaporator. The air conditioner may be operated by switching. For example, when the air conditioner is started at a low outside air temperature (0 ° C. or lower), the compressor 310 is rotated at a predetermined rotational speed in order to eliminate the refrigerant stagnation (the state in which the refrigerant is dissolved in the refrigerating machine oil of the compressor 310). And the compressor 310 is controlled to warm up quickly. At this time, there is a risk that refrigerant stagnation may occur due to an increase in the pressure inside the compressor 310, that is, the discharge pressure (high pressure) of the compressor 310. In addition, when the air conditioner is started, the amount of refrigerating machine oil sucked into the compressor 310 (returning to the compressor 310 from the refrigerant circuit) with respect to the amount of refrigerating machine oil discharged from the compressor 310 to the refrigerant circuit together with the refrigerant. Therefore, the compressor 310 may run out of refrigeration oil and cause poor lubrication.

以上のような場合に、室外熱交換器３３０ａが凝縮器、室外熱交換器３３０ｂが蒸発器として機能するよう、四方弁３２０ａおよび四方弁３２０ｂを切り替える。このように冷媒回路を切り替えれば、室外熱交換器３３０ａが凝縮器として機能していることによって圧縮機３１０の吐出圧力が低下し、吐出圧力の上昇に起因する冷媒寝込みを抑制できる。また、圧縮機３１０から吐出された冷媒が、四方弁３２０ａ→室外熱交換器３３０ａ→第２の分岐点３７０→室外熱交換器３３０ｂ→四方弁３２０ｂ、の順に流れて圧縮機３１０に吸入されることによって、冷媒が室内機を循環して圧縮機３１０に吸入される場合と比べて早く圧縮機３１０に戻るので、冷媒とともに圧縮機３１０から吐出された冷凍機油も早く圧縮機３１０に戻り、潤滑不良を回避できる。 In such a case, the four-way valve 320a and the four-way valve 320b are switched so that the outdoor heat exchanger 330a functions as a condenser and the outdoor heat exchanger 330b functions as an evaporator. By switching the refrigerant circuit in this way, the outdoor heat exchanger 330a functions as a condenser, so that the discharge pressure of the compressor 310 decreases, and the refrigerant stagnation due to the increase in the discharge pressure can be suppressed. Further, the refrigerant discharged from the compressor 310 flows in the order of the four-way valve 320a → the outdoor heat exchanger 330a → the second branch point 370 → the outdoor heat exchanger 330b → the four-way valve 320b and is sucked into the compressor 310. As a result, the refrigerant returns to the compressor 310 earlier than when the refrigerant circulates through the indoor unit and is sucked into the compressor 310, so that the refrigerating machine oil discharged from the compressor 310 together with the refrigerant also returns to the compressor 310 earlier and lubricates. Defects can be avoided.

室外熱交換器３３０ａが凝縮器、室外熱交換器３３０ｂが蒸発器として機能するようにして空気調和装置を運転しているときは、四方弁３２０ｂが切り替わることによって、圧縮機３１０から吐出された冷媒の一部が、四方弁３２０ｂ→第３の分岐点３８０→四方弁３２０ａ→第４の分岐点３９０と流れて圧縮機３１０に吸入される（以降、冷媒のショートカットと記載する場合がある）という問題がある。 When operating the air conditioner so that the outdoor heat exchanger 330a functions as a condenser and the outdoor heat exchanger 330b functions as an evaporator, the refrigerant discharged from the compressor 310 is switched by switching the four-way valve 320b. A part of the flow flows through the four-way valve 320b → the third branch point 380 → the four-way valve 320a → the fourth branch point 390 and is sucked into the compressor 310 (hereinafter, sometimes referred to as a refrigerant shortcut). There's a problem.

しかし、この空気調和装置には、上述したように、四方弁３２０ｂと第３の分岐点とを繋ぐ配管に逆止弁３４０が設けられており、かつ、逆止弁３４０は、低圧側（第３の分岐点側）から高圧側（四方弁３２０ｂ側）への冷媒の流れのみ許容するように配置されている。これにより、室外熱交換器３３０ａが凝縮器、室外熱交換器３３０ｂが蒸発器として機能するよう、四方弁３２０ａおよび四方弁３２０ｂをそれぞれ切り替えても、四方弁３２０ｂから第３の分岐点３８０に向かって流れる冷媒が逆止弁３４０によって堰き止められるので、冷媒のショートカットが発生しない。 However, in this air conditioner, as described above, the check valve 340 is provided in the pipe connecting the four-way valve 320b and the third branch point, and the check valve 340 is provided on the low pressure side (first 3 is arranged so as to allow only the flow of refrigerant from the high-pressure side (four-way valve 320b side). As a result, even if the four-way valve 320a and the four-way valve 320b are switched so that the outdoor heat exchanger 330a functions as a condenser and the outdoor heat exchanger 330b functions as an evaporator, the four-way valve 320b moves to the third branch point 380. The refrigerant flowing through is blocked by the check valve 340, so that no refrigerant shortcut occurs.

特開２００５−４９０５１号公報JP-A-2005-49051

特許文献１に記載の空気調和装置において暖房運転を行うとき、室外熱交換器３３０ａと室外熱交換器３３０ｂとを蒸発器として機能させるよう、四方弁３２０ａと四方弁３２０ｂとがそれぞれ切り替えられる。このとき、圧縮機３１０から吐出された冷媒は、四方弁３２０ａ側と四方弁３２０ｂ側とに分流し、四方弁３２０ａに流入した冷媒は室内熱交換器４２０に流入する。 When performing the heating operation in the air conditioner described in Patent Literature 1, the four-way valve 320a and the four-way valve 320b are switched so that the outdoor heat exchanger 330a and the outdoor heat exchanger 330b function as evaporators. At this time, the refrigerant discharged from the compressor 310 is divided into the four-way valve 320a side and the four-way valve 320b side, and the refrigerant flowing into the four-way valve 320a flows into the indoor heat exchanger 420.

一方、四方弁３２０ｂに流入した冷媒は、四方弁３２０ｂと第３の分岐点とを繋ぐ配管に設けられた逆止弁３４０によって堰き止められる。このため、冷媒および冷媒とともに圧縮機３１０から吐出された冷凍機油は、第１の分岐点３６０から逆止弁３４０までの間の配管に滞留する。そして、この状態が継続すれば、圧縮機３１０で冷凍機油が不足する虞があった。また、冷凍機油不足を解消するために、一旦暖房運転を停止し室外熱交換器３３０ａと室外熱交換器３３０ｂとを凝縮器として機能させるよう、四方弁３２０ａと四方弁３２０ｂとをそれぞれ切り替えて（つまり、冷媒回路を冷房運転時の状態として）油戻し運転を行うことが考えられるが、上述した冷凍機油不足の問題は暖房運転を行う度に発生するので、油戻し運転の頻度が多くなり、暖房運転が頻繁に中断され使用者の快適性を損なう虞があった。 On the other hand, the refrigerant flowing into the four-way valve 320b is blocked by a check valve 340 provided in a pipe connecting the four-way valve 320b and the third branch point. For this reason, the refrigerating machine oil discharged from the compressor 310 together with the refrigerant and the refrigerant stays in the pipe from the first branch point 360 to the check valve 340. If this state continues, the compressor 310 may run out of refrigeration oil. In order to solve the shortage of refrigerating machine oil, the heating operation is temporarily stopped and the four-way valve 320a and the four-way valve 320b are respectively switched so that the outdoor heat exchanger 330a and the outdoor heat exchanger 330b function as a condenser ( In other words, it is conceivable to perform the oil return operation (with the refrigerant circuit in the cooling operation state), but the above-mentioned problem of insufficient refrigeration oil occurs every time the heating operation is performed, so the frequency of the oil return operation increases. Heating operation is frequently interrupted, which may impair user comfort.

本発明は以上述べた問題点を解決するものであって、冷媒のショートカットを防止しつつ頻繁な暖房運転の中断が発生しないようにした空気調和装置を提供することを目的とする。 The present invention solves the above-described problems, and an object thereof is to provide an air conditioner that prevents frequent interruption of heating operation while preventing a refrigerant shortcut.

上記の課題を解決するために、本発明の空気調和装置は、室外機と室内機とを有し、室外機と室内機とがガス管と液管とによって接続されるものであって、室外機は、圧縮機と、圧縮機の冷媒吐出側に接続された吐出管と、圧縮機の冷媒吸入側に接続された吸入管と、室外機ガス管と、室内機液管と、複数の室外熱交換器ユニットとを有している。室外熱交換器ユニットは、室外熱交換器と、四方弁と、四方弁の第１のポートと吐出管とを接続する吐出分管と、四方弁の第２のポートと室外熱交換器の一方の冷媒出入口とを接続する接続配管と、四方弁の第３のポートと吸入管とを接続する吸入分管と、四方弁の第４のポートと室外機ガス管とを接続するガス分管と、室外熱交換器の他方の冷媒出入口と室外機液管とを接続する液分管とを有している。そして、複数の室外熱交換器ユニットのうち少なくとも一つの室外熱交換器ユニットが有する吐出分管またはガス分管のうちいずれか一方に開閉手段を設けている。 In order to solve the above-described problems, an air conditioner of the present invention includes an outdoor unit and an indoor unit, and the outdoor unit and the indoor unit are connected by a gas pipe and a liquid pipe. The compressor includes a compressor, a discharge pipe connected to the refrigerant discharge side of the compressor, a suction pipe connected to the refrigerant suction side of the compressor, an outdoor unit gas pipe, an indoor unit liquid pipe, and a plurality of outdoor units. And a heat exchanger unit. The outdoor heat exchanger unit includes an outdoor heat exchanger, a four-way valve, a discharge branch pipe connecting the first port of the four-way valve and the discharge pipe, a second port of the four-way valve, and one of the outdoor heat exchangers. A connection pipe connecting the refrigerant inlet / outlet, a suction branch pipe connecting the third port of the four-way valve and the suction pipe, a gas branch pipe connecting the fourth port of the four-way valve and the outdoor unit gas pipe, and outdoor heat A liquid distribution pipe connecting the other refrigerant inlet / outlet of the exchanger and the outdoor unit liquid pipe; And the opening / closing means is provided in any one of the discharge distribution pipe or the gas distribution pipe which at least 1 outdoor heat exchanger unit has among several outdoor heat exchanger units.

上記のように構成した本発明の空気調和装置によれば、複数の室外熱交換器のうち少なくとも１つの室外熱交換器を蒸発器として機能させ、残りの室外熱交換器を凝縮器として機能させるときに、開閉手段が設けられた吐出分管あるいは開閉手段が設けられたガス分管が設けられた室外熱交換器ユニットの室外熱交換器を蒸発器として機能させるよう当該四方弁を切り替えるとともに、開閉手段を閉じる。これにより、冷媒のショートカットを防止できる。また、複数の室外熱交換器を全て蒸発器として機能させるとき、つまり、暖房運転を行うときは、開閉手段を開くことによって冷凍機油の滞留を防止できるので、圧縮機の冷凍機油不足や油戻し運転による暖房運転の頻繁な中断を防止できる。 According to the air conditioner of the present invention configured as described above, at least one outdoor heat exchanger among a plurality of outdoor heat exchangers functions as an evaporator, and the remaining outdoor heat exchangers function as a condenser. Sometimes, the four-way valve is switched so that the outdoor heat exchanger of the outdoor heat exchanger unit provided with the discharge distribution pipe provided with the opening / closing means or the gas distribution pipe provided with the opening / closing means functions as an evaporator, and the opening / closing means Close. Thereby, the shortcut of a refrigerant | coolant can be prevented. In addition, when all the outdoor heat exchangers function as evaporators, that is, when heating operation is performed, stagnation of refrigeration oil can be prevented by opening the opening / closing means. It is possible to prevent frequent interruption of heating operation due to operation.

本発明の実施形態における、冷房運転を行うときの空気調和装置の冷媒回路図である。It is a refrigerant circuit figure of an air harmony device when performing cooling operation in an embodiment of the present invention. 本発明の実施形態における、暖房運転を行うときの空気調和装置の冷媒回路図である。It is a refrigerant circuit figure of an air harmony device when performing heating operation in an embodiment of the present invention. 本発明の実施形態における、凝縮器−蒸発器混在運転を行うときの空気調和装置の冷媒回路図である。It is a refrigerant circuit diagram of the air conditioning apparatus when performing the condenser-evaporator mixed operation in the embodiment of the present invention. 従来の空気調和装置の冷媒回路図である。It is a refrigerant circuit figure of the conventional air conditioning apparatus.

以下、本発明の実施の形態を、添付図面に基づいて詳細に説明する。実施形態としては、１台の室外機に３台の室内機が並列に接続され、全ての室内機で同時に冷房運転あるいは暖房運転が行える空気調和装置を例に挙げて説明する。尚、本発明は以下の実施形態に限定されることはなく、本発明の主旨を逸脱しない範囲で種々変形することが可能である。 Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. As an embodiment, an air conditioning apparatus will be described as an example in which three indoor units are connected in parallel to one outdoor unit, and cooling operation or heating operation can be performed simultaneously in all indoor units. The present invention is not limited to the following embodiments, and can be variously modified without departing from the gist of the present invention.

図１に示すように、本実施形態における空気調和装置１は、屋外に設置される１台の室外機２と、屋内に設置され、室外機２に液管８およびガス管９で並列に接続された３台の室内機５ａ〜５ｃとを備えている。詳細には、液管８は、一端が室外機２の閉鎖弁２５に、他端が分岐して室内機５ａ〜５ｃの各液管接続部５３ａ〜５３ｃに、それぞれ接続されている。また、ガス管９は、一端が室外機２の閉鎖弁２６に、他端が分岐して室内機５ａ〜５ｃの各ガス管接続部５４ａ〜５４ｃに、それぞれ接続されている。以上により、空気調和装置１の冷媒回路１００が構成されている。 As shown in FIG. 1, an air conditioner 1 according to the present embodiment is installed indoors with one outdoor unit 2 and is connected indoors in parallel with a liquid pipe 8 and a gas pipe 9. The three indoor units 5a to 5c are provided. Specifically, the liquid pipe 8 has one end connected to the closing valve 25 of the outdoor unit 2 and the other end branched to be connected to the liquid pipe connecting portions 53a to 53c of the indoor units 5a to 5c. The gas pipe 9 has one end connected to the closing valve 26 of the outdoor unit 2 and the other end branched to be connected to the gas pipe connecting portions 54a to 54c of the indoor units 5a to 5c. The refrigerant circuit 100 of the air conditioner 1 is configured as described above.

まずは、室外機２について説明する。室外機２は、圧縮機２１と、第１四方弁２２ａと、第２四方弁２２ｂと、第１室外熱交換器２３ａと、第２室外熱交換器２３ｂと、第１室外膨張弁２４ａと、第２室外膨張弁２４ｂと、液管８の一端が接続された閉鎖弁２５と、ガス管９の一端が接続された閉鎖弁２６と、室外ファン２７と、開閉手段である電磁開閉弁２８とを備えている。そして、室外ファン２７を除くこれら各装置が以下で詳述する各冷媒配管で相互に接続されて、冷媒回路１００の一部をなす室外機冷媒回路２０を構成している。 First, the outdoor unit 2 will be described. The outdoor unit 2 includes a compressor 21, a first four-way valve 22a, a second four-way valve 22b, a first outdoor heat exchanger 23a, a second outdoor heat exchanger 23b, a first outdoor expansion valve 24a, A second outdoor expansion valve 24b; a closing valve 25 to which one end of the liquid pipe 8 is connected; a closing valve 26 to which one end of the gas pipe 9 is connected; an outdoor fan 27; It has. These devices other than the outdoor fan 27 are connected to each other through refrigerant pipes described in detail below to constitute an outdoor unit refrigerant circuit 20 that forms part of the refrigerant circuit 100.

圧縮機２１は、インバータにより回転数が制御される図示しないモータによって駆動されることで、運転容量を可変できる能力可変型圧縮機である。圧縮機２１の冷媒吐出側には吐出管４１の一端が接続されており、吐出管４１の他端は第１吐出分管４１ａと第２吐出分管４１ｂとに分岐している。第１吐出分管４１ａは後述する第１四方弁２２ａのポートａに接続されており、第２吐出分管４１ｂは後述する第２四方弁２２ｂのポートｅに接続されている。 The compressor 21 is a variable capacity compressor that can vary its operating capacity by being driven by a motor (not shown) whose rotation speed is controlled by an inverter. One end of a discharge pipe 41 is connected to the refrigerant discharge side of the compressor 21, and the other end of the discharge pipe 41 is branched into a first discharge branch pipe 41a and a second discharge branch pipe 41b. The first discharge branch pipe 41a is connected to a port a of a first four-way valve 22a described later, and the second discharge branch pipe 41b is connected to a port e of a second four-way valve 22b described later.

また、圧縮機２１の冷媒吸入側には吸入管４２の一端が接続されており、吸入管４２の他端は第１吸入分管４２ａと第２吸入分管４２ｂとに分岐している。第１吸入分管４２ａは後述する第１四方弁２２ａのポートｃに接続されており、第２吸入分管４２ｂは後述する第２四方弁２２ｂのポートｇに接続されている。 Further, one end of a suction pipe 42 is connected to the refrigerant suction side of the compressor 21, and the other end of the suction pipe 42 is branched into a first suction distribution pipe 42a and a second suction distribution pipe 42b. The first suction distribution pipe 42a is connected to a port c of a first four-way valve 22a described later, and the second suction distribution pipe 42b is connected to a port g of a second four-way valve 22b described later.

第１四方弁２２ａおよび第２四方弁２２ｂは、冷媒の流れる方向を切り換えるための弁であり、第１四方弁２２ａはａ、ｂ、ｃ、ｄの４つのポートを、第２四方弁２２ｂはｅ、ｆ、ｇ、ｈの４つのポートを、それぞれ備えている。第１四方弁２２ａではポートａ、ｂ、ｃ、ｄの順に、また、第２四方弁２２ｂではポートｅ、ｆ、ｇ、ｈの順に、本発明における四方弁の第１、第２、第３、第４ポートに相当する。第１四方弁２２ａでは、ポートａには、上述したように第１吐出分管４１ａが接続されている。ポートｂは、第１室外熱交換器２３ａの一方の冷媒出入口と第１接続配管４３ａで接続されている。ポートｃには、上述したように第１吸入分管４２ａが接続されている。そして、ポートｄには、第１ガス分管４５ａの一端が接続されている。 The first four-way valve 22a and the second four-way valve 22b are valves for switching the flow direction of the refrigerant. The first four-way valve 22a has four ports a, b, c, and d, and the second four-way valve 22b has Each of the four ports e, f, g, and h is provided. In the first four-way valve 22a, the ports a, b, c, and d are arranged in this order, and in the second four-way valve 22b, the ports e, f, g, and h are arranged in the order of the first, second, and third. , Corresponding to the fourth port. In the first four-way valve 22a, the first discharge branch pipe 41a is connected to the port a as described above. The port b is connected to one refrigerant inlet / outlet of the first outdoor heat exchanger 23a by the first connection pipe 43a. As described above, the first suction distribution pipe 42a is connected to the port c. One end of the first gas distribution pipe 45a is connected to the port d.

一方、第２四方弁２２ｂでは、ポートｅには、上述したように第２吐出分管４１ｂが接続されている。ポートｆは、第２室外熱交換器２３ｂの一方の冷媒出入口と第２接続配管４３ｂで接続されている。ポートｇには、上述したように第２吸入分管４２ｂが接続されている。そして、ポートｈには、第２ガス分管４５ｂの一端が接続されている。
尚、第１ガス分管４５ａの他端と第２ガス分管４５ｂの他端とは、各々室外機ガス管４５の一端に接続され、室外機ガス管４５の他端は閉鎖弁２６に接続されている。 On the other hand, in the second four-way valve 22b, the second discharge distribution pipe 41b is connected to the port e as described above. The port f is connected to one refrigerant inlet / outlet of the second outdoor heat exchanger 23b through the second connection pipe 43b. As described above, the second suction branch pipe 42b is connected to the port g. One end of the second gas distribution pipe 45b is connected to the port h.
The other end of the first gas distribution pipe 45a and the other end of the second gas distribution pipe 45b are each connected to one end of the outdoor unit gas pipe 45, and the other end of the outdoor unit gas pipe 45 is connected to the closing valve 26. Yes.

第１室外熱交換器２３ａおよび第２室外熱交換器２３ｂは、冷媒と、後述する室外ファン２７の回転により室外機２の内部に取り込まれた外気とを熱交換させるものである。第１室外熱交換器２３ａの一方の冷媒出入口は、上述したように第１四方弁２２ａのポートｂに第１接続配管４３ａで接続され、他方の冷媒出入口には第１液分管４４ａの一端が接続されている。 The first outdoor heat exchanger 23a and the second outdoor heat exchanger 23b exchange heat between the refrigerant and the outside air taken into the outdoor unit 2 by the rotation of the outdoor fan 27 described later. As described above, one refrigerant inlet / outlet of the first outdoor heat exchanger 23a is connected to the port b of the first four-way valve 22a by the first connection pipe 43a, and one end of the first liquid distribution pipe 44a is connected to the other refrigerant inlet / outlet. It is connected.

また、第２室外熱交換器２３ｂの一方の冷媒出入口は、上述したように第２四方弁２２ｂのポートｆに第２接続配管４３ｂで接続され、他方の冷媒出入口には第２液分管４４ｂの一端が接続されている。
尚、第１液分管４４ａの他端と第２液分管４４ｂの他端とは、各々室外機液管４４の一端に接続され、室外機液管４４の他端は閉鎖弁２５に接続されている。 Further, as described above, one refrigerant inlet / outlet of the second outdoor heat exchanger 23b is connected to the port f of the second four-way valve 22b by the second connection pipe 43b, and the other refrigerant inlet / outlet is connected to the second liquid distribution pipe 44b. One end is connected.
The other end of the first liquid distribution pipe 44a and the other end of the second liquid distribution pipe 44b are each connected to one end of the outdoor unit liquid pipe 44, and the other end of the outdoor unit liquid pipe 44 is connected to the closing valve 25. Yes.

第１室外膨張弁２４ａおよび第２室外膨張弁２４ｂは、電子膨張弁である。第１室外膨張弁２４ａは、第１液分管４４ａに設けられており、その開度が調整されることで、第１室外熱交換器２３ａに流入する冷媒量、あるいは、第１室外熱交換器２３ａから流出する冷媒量を調整する。第２室外膨張弁２４ｂは、第２液分管４４ｂに設けられており、その開度が調整されることで、第２室外熱交換器２３ｂに流入する冷媒量、あるいは、第２室外熱交換器２３ｂから流出する冷媒量を調整する。 The first outdoor expansion valve 24a and the second outdoor expansion valve 24b are electronic expansion valves. The first outdoor expansion valve 24a is provided in the first liquid distribution pipe 44a, and the amount of refrigerant flowing into the first outdoor heat exchanger 23a or the first outdoor heat exchanger is adjusted by adjusting the opening degree thereof. The amount of refrigerant flowing out of 23a is adjusted. The second outdoor expansion valve 24b is provided in the second liquid distribution pipe 44b, and the amount of refrigerant flowing into the second outdoor heat exchanger 23b or the second outdoor heat exchanger is adjusted by adjusting the opening degree thereof. The amount of refrigerant flowing out of 23b is adjusted.

室外ファン２７は樹脂材で形成されており、第１室外熱交換器２３ａおよび第２室外熱交換器２３ｂの近傍に配置されている。室外ファン２７は、図示しないファンモータによって回転することで図示しない吸込口から室外機２の内部へ外気を取り込み、第１室外熱交換器２３ａや第２室外熱交換器２３ｂにおいて冷媒と熱交換した外気を図示しない吹出口から室外機２の外部へ放出する。 The outdoor fan 27 is formed of a resin material, and is disposed in the vicinity of the first outdoor heat exchanger 23a and the second outdoor heat exchanger 23b. The outdoor fan 27 is rotated by a fan motor (not shown) to take outside air into the outdoor unit 2 from a suction port (not shown), and exchanges heat with the refrigerant in the first outdoor heat exchanger 23a and the second outdoor heat exchanger 23b. Outside air is discharged to the outside of the outdoor unit 2 from a blower outlet (not shown).

電磁開閉弁２８は、第２吐出分管４１ｂに設けられている。電磁開閉弁２８が開閉することで、第２吐出分管４１ｂを冷媒が流れるよう、あるいは、冷媒が流れないようにできる。
尚、第１室外熱交換器２３ａと、第１四方弁２２ａと、第１吐出分管４１ａと、第１接続配管４３ａと、第１吸入分管４２ａと、第１ガス分管４５ａと、第１液分管４４ａとで、第１室外熱交換器ユニット２０ａが構成され、第２室外熱交換器２３ｂと、第２四方弁２２ｂと、第２吐出分管４１ｂと、第２接続配管４３ｂと、第２吸入分管４２ｂと、第２ガス分管４５ｂと、第２液分管４４ｂとで、第２室外熱交換器ユニット２０ｂが構成される。これら第１室外熱交換器ユニット２０ａおよび第２室外熱交換器ユニット２０ｂが、本発明における複数の室外熱交換器ユニットに相当する。 The electromagnetic open / close valve 28 is provided in the second discharge distribution pipe 41b. By opening and closing the electromagnetic on-off valve 28, it is possible to prevent the refrigerant from flowing through the second discharge distribution pipe 41b or to prevent the refrigerant from flowing.
The first outdoor heat exchanger 23a, the first four-way valve 22a, the first discharge distribution pipe 41a, the first connection pipe 43a, the first suction distribution pipe 42a, the first gas distribution pipe 45a, and the first liquid distribution pipe 44a constitutes the first outdoor heat exchanger unit 20a, the second outdoor heat exchanger 23b, the second four-way valve 22b, the second discharge branch pipe 41b, the second connection pipe 43b, and the second suction branch pipe. 42b, the 2nd gas distribution pipe 45b, and the 2nd liquid distribution pipe 44b comprise the 2nd outdoor heat exchanger unit 20b. The first outdoor heat exchanger unit 20a and the second outdoor heat exchanger unit 20b correspond to a plurality of outdoor heat exchanger units in the present invention.

以上説明した構成の他に、室外機２には各種のセンサが設けられている。図１に示すように、吐出管４１には、圧縮機２１から吐出される冷媒の圧力を検出する高圧センサ３１と、圧縮機２１から吐出される冷媒の温度を検出する吐出温度センサ３３が設けられている。吸入管４２には、圧縮機２１に吸入される冷媒の圧力を検出する低圧センサ３２と、圧縮機２１に吸入される冷媒の温度を検出する吸入温度センサ３４とが設けられている。 In addition to the configuration described above, the outdoor unit 2 is provided with various sensors. As shown in FIG. 1, the discharge pipe 41 is provided with a high-pressure sensor 31 that detects the pressure of refrigerant discharged from the compressor 21 and a discharge temperature sensor 33 that detects the temperature of refrigerant discharged from the compressor 21. It has been. The suction pipe 42 is provided with a low pressure sensor 32 that detects the pressure of the refrigerant sucked into the compressor 21 and a suction temperature sensor 34 that detects the temperature of the refrigerant sucked into the compressor 21.

第１液分管４４ａにおける第１室外熱交換器２３ａと第１室外膨張弁４４ａとの間には、第１室外熱交換器２３ａに流入する、または、第１室外熱交換器２３ａから流出する冷媒の温度を検出する第１熱交温度センサ３５ａが設けられている。また、第２液分管４４ｂにおける第２室外熱交換器２３ｂと第２室外膨張弁４４ｂとの間には、第２室外熱交換器２３ｂに流入する、または、第２室外熱交換器２３ｂから流出する冷媒の温度を検出する第２熱交温度センサ３５ｂが設けられている。そして、室外機２の図示しない吸込口付近には、室外機２の内部に流入する外気の温度、すなわち外気温度を検出する外気温度センサ３６が備えられている。 Between the first outdoor heat exchanger 23a and the first outdoor expansion valve 44a in the first liquid distribution pipe 44a, the refrigerant flows into the first outdoor heat exchanger 23a or flows out from the first outdoor heat exchanger 23a. The 1st heat exchange temperature sensor 35a which detects the temperature of this is provided. Further, between the second outdoor heat exchanger 23b and the second outdoor expansion valve 44b in the second liquid distribution pipe 44b, the gas flows into the second outdoor heat exchanger 23b or flows out from the second outdoor heat exchanger 23b. A second heat exchange temperature sensor 35b is provided for detecting the temperature of the refrigerant to be used. An outdoor air temperature sensor 36 that detects the temperature of the outside air that flows into the outdoor unit 2, that is, the outside air temperature, is provided near the suction port (not shown) of the outdoor unit 2.

また、室外機２には、室外機制御手段２００が備えられている。室外機制御手段２００は、室外機２の図示しない電装品箱に格納されている制御基板に搭載されている。図１の拡大図に示すように、室外機制御手段２００は、ＣＰＵ２１０と、記憶部２２０と、通信部２３０とを備えている。 The outdoor unit 2 includes an outdoor unit control means 200. The outdoor unit control means 200 is mounted on a control board stored in an electrical component box (not shown) of the outdoor unit 2. As shown in the enlarged view of FIG. 1, the outdoor unit control means 200 includes a CPU 210, a storage unit 220, and a communication unit 230.

記憶部２２０は、ＲＯＭやＲＡＭで構成されており、室外機２の制御プログラムや各種センサからの検出信号に対応した検出値、圧縮機２１や室外ファン２７の制御状態等を記憶している。通信部２３０は、室内機５ａ〜５ｃとの通信を行うためのインターフェイスである。 The storage unit 220 includes a ROM and a RAM, and stores a control program for the outdoor unit 2, detection values corresponding to detection signals from various sensors, control states of the compressor 21 and the outdoor fan 27, and the like. The communication unit 230 is an interface for performing communication with the indoor units 5a to 5c.

ＣＰＵ２１０は、前述した室外機２の各センサでの検出結果を取り込む。また、ＣＰＵ２１０は、室内機５ａ〜５ｃから送信される制御信号を通信部２３０を介して取り込む。ＣＰＵ２１０は、取り込んだ検出結果や制御信号に基づいて、圧縮機２１や室外ファン２７の駆動制御を行う。また、ＣＰＵ２１０は、取り込んだ検出結果や制御信号に基づいて、第１四方弁２２ａや第２四方弁２２ｂの切り換え制御を行う。さらには、ＣＰＵ２１０は、取り込んだ検出結果や制御信号に基づいて、第１室外膨張弁２４ａや第２室外膨張弁２４ｂの開度制御を行う。 CPU210 takes in the detection result in each sensor of outdoor unit 2 mentioned above. In addition, the CPU 210 takes in control signals transmitted from the indoor units 5 a to 5 c via the communication unit 230. The CPU 210 performs drive control of the compressor 21 and the outdoor fan 27 based on the detection results and control signals taken in. In addition, the CPU 210 performs switching control of the first four-way valve 22a and the second four-way valve 22b based on the detection results and control signals taken in. Furthermore, the CPU 210 controls the opening degree of the first outdoor expansion valve 24a and the second outdoor expansion valve 24b based on the acquired detection result and control signal.

次に、３台の室内機５ａ〜５ｃについて説明する。３台の室内機５ａ〜５ｃは、それぞれ室内熱交換器５１ａ〜５１ｃと、室内膨張弁５２ａ〜５２ｃと、分岐した液管８の他端が接続された液管接続部５３ａ〜５３ｃと、分岐したガス管９の他端が接続されたガス管接続部５４ａ〜５４ｃと、室内ファン５５ａ〜５５ｃとを備えている。そして、室内ファン５５ａ〜５５ｃを除くこれら各装置が以下で詳述する各冷媒配管で相互に接続されて、冷媒回路１００の一部をなす室内機冷媒回路５０ａ〜５０ｃを構成している。 Next, the three indoor units 5a to 5c will be described. The three indoor units 5a to 5c are respectively branched into indoor heat exchangers 51a to 51c, indoor expansion valves 52a to 52c, and liquid pipe connection portions 53a to 53c to which the other ends of the branched liquid pipes 8 are connected. Gas pipe connection portions 54a to 54c to which the other ends of the gas pipes 9 are connected are provided, and indoor fans 55a to 55c are provided. And these each apparatus except indoor fan 55a-55c is mutually connected by each refrigerant | coolant piping explained in full detail below, and comprises the indoor unit refrigerant circuit 50a-50c which makes a part of refrigerant circuit 100. FIG.

尚、室内機５ａ〜５ｃの構成は全て同じであるため、以下の説明では、室内機５ａの構成についてのみ説明を行い、その他の室内機５ｂ、５ｃについては説明を省略する。また、図１では、室内機５ａの構成装置に付与した番号の末尾をａからｂおよびｃにそれぞれ変更したものが、室外機５ａの構成装置と対応する室内機５ｂ、５ｃの構成装置となる。 In addition, since the structure of all the indoor units 5a-5c is the same, in the following description, only the structure of the indoor unit 5a is demonstrated and description is abbreviate | omitted about the other indoor units 5b and 5c. Moreover, in FIG. 1, what changed the end of the number provided to the component apparatus of the indoor unit 5a from a to b and c becomes the component apparatus of the indoor units 5b and 5c corresponding to the component apparatus of the outdoor unit 5a. .

室内熱交換器５１ａは、冷媒と後述する室内ファン５５ａの回転により図示しない吸込口から室内機５ａの内部に取り込まれた室内空気とを熱交換させるものであり、一方の冷媒出入口が液管接続部５３ａに室内機液管７１ａで接続され、他方の冷媒出入口がガス管接続部５４ａに室内機ガス管７２ａで接続されている。室内熱交換器５１ａは、室内機５ａが冷房運転を行う場合は蒸発器として機能し、室内機５ａが暖房運転を行う場合は凝縮器として機能する。
尚、液管接続部５３ａやガス管接続部５４ａには、各冷媒配管が溶接やフレアナット等により接続されている。 The indoor heat exchanger 51a exchanges heat between the refrigerant and room air taken into the interior of the indoor unit 5a through a suction port (not shown) by rotation of an indoor fan 55a, which will be described later. The indoor unit liquid pipe 71a is connected to the section 53a, and the other refrigerant inlet / outlet is connected to the gas pipe connecting section 54a through the indoor unit gas pipe 72a. The indoor heat exchanger 51a functions as an evaporator when the indoor unit 5a performs a cooling operation, and functions as a condenser when the indoor unit 5a performs a heating operation.
Each refrigerant pipe is connected to the liquid pipe connecting portion 53a and the gas pipe connecting portion 54a by welding, a flare nut or the like.

室内膨張弁５２ａは、室内機液管７１ａに設けられている。室内膨張弁５２ａは電子膨張弁であり、その開度を調整することによって室内熱交換器５１ａに流れる冷媒量を調整することができる。室内膨張弁５２ａは、室内熱交換器５１ａが蒸発器として機能する場合は、その開度が要求される冷房能力に応じて調整され、室内熱交換器５１ａが凝縮器として機能する場合は、その開度が要求される暖房能力に応じて調整される。 The indoor expansion valve 52a is provided in the indoor unit liquid pipe 71a. The indoor expansion valve 52a is an electronic expansion valve, and the amount of refrigerant flowing through the indoor heat exchanger 51a can be adjusted by adjusting the opening degree thereof. When the indoor heat exchanger 51a functions as an evaporator, the indoor expansion valve 52a is adjusted according to the required cooling capacity, and when the indoor heat exchanger 51a functions as a condenser, The opening is adjusted according to the required heating capacity.

室内ファン５５ａは樹脂材で形成されており、室内熱交換器５１ａの近傍に配置されている。室内ファン５５ａは、図示しないファンモータによって回転することで、図示しない吸込口から室内機５ａ内に室内空気を取り込み、室内熱交換器５１ａにおいて冷媒と熱交換した室内空気を図示しない吹出口から室内へ供給する。 The indoor fan 55a is formed of a resin material and is disposed in the vicinity of the indoor heat exchanger 51a. The indoor fan 55a is rotated by a fan motor (not shown) to take indoor air into the indoor unit 5a from a suction port (not shown), and the indoor air exchanged with the refrigerant in the indoor heat exchanger 51a from the blower outlet (not shown) to the room. To supply.

以上説明した構成の他に、室内機５ａには各種のセンサが設けられている。室内機液管７１ａにおける室内熱交換器５１ａと室内膨張弁５２ａとの間には、室内熱交換器５１ａに流入あるいは室内熱交換器５１ａから流出する冷媒の温度を検出する液側温度センサ６１ａが設けられている。室内機ガス管７２ａには、室内熱交換器５１ａから流出あるいは室内熱交換器５１ａに流入する冷媒の温度を検出するガス側温度センサ６２ａが設けられている。そして、室内機５ａの図示しない吸込口付近には、室内機５ａ内に流入する室内空気の温度、すなわち室内温度を検出する室内温度センサ６３ａが備えられている。 In addition to the configuration described above, the indoor unit 5a is provided with various sensors. Between the indoor heat exchanger 51a and the indoor expansion valve 52a in the indoor unit liquid pipe 71a, a liquid side temperature sensor 61a that detects the temperature of the refrigerant flowing into or out of the indoor heat exchanger 51a. Is provided. The indoor unit gas pipe 72a is provided with a gas side temperature sensor 62a that detects the temperature of the refrigerant flowing out of the indoor heat exchanger 51a or flowing into the indoor heat exchanger 51a. An indoor temperature sensor 63a that detects the temperature of the indoor air flowing into the indoor unit 5a, that is, the indoor temperature, is provided in the vicinity of a suction port (not shown) of the indoor unit 5a.

尚、図示は省略するが室内機５ａの電装品箱に格納された制御基板には、室内機制御手段が搭載されている。室内機制御手段には、液側温度センサ６１ａやガス側温度センサ６２ａや室内温度センサ６３ａで検出した検出値が入力され、また、使用者が図示しないリモコンを操作して設定した運転条件（設定温度や風量等）を含んだ信号が入力される。室内機制御手段は、これら入力された各種情報や後述する室外機制御手段２００から送信される制御信号に基づいて、室内膨張弁５２ａの開度制御や、室内ファン５５ａの駆動制御を行う。 Although illustration is omitted, an indoor unit control means is mounted on the control board stored in the electrical component box of the indoor unit 5a. The detected values detected by the liquid side temperature sensor 61a, the gas side temperature sensor 62a, and the room temperature sensor 63a are input to the indoor unit control means, and the operating conditions (settings) set by the user by operating a remote controller (not shown) A signal including temperature and air volume is input. The indoor unit control means controls the opening degree of the indoor expansion valve 52a and the drive control of the indoor fan 55a based on the inputted various information and a control signal transmitted from the outdoor unit control means 200 described later.

次に、本実施形態における空気調和装置１の運転時の冷媒回路１００における冷媒の流れや各部の動作について、図１乃至図３を用いて説明する。本実施形態における空気調和装置１は、室内機５ａ〜５ｃが設置された室内の冷房を行う冷房運転と、室内機５ａ〜５ｃが設置された室内の暖房を行う暖房運転と、空気調和装置１の起動時に、第１室外熱交換器２３ａを凝縮器として、第２室外熱交換器２３ｂを蒸発器としてそれぞれ機能させ、起動時の圧縮機１における冷凍機油不足を抑制するための混在運転とを行うことができる。 Next, the flow of the refrigerant and the operation of each part in the refrigerant circuit 100 during operation of the air-conditioning apparatus 1 in the present embodiment will be described with reference to FIGS. 1 to 3. The air conditioning apparatus 1 according to the present embodiment includes a cooling operation for performing cooling of the room in which the indoor units 5a to 5c are installed, a heating operation for heating the room in which the indoor units 5a to 5c are installed, and the air conditioning apparatus 1. The first outdoor heat exchanger 23a functions as a condenser and the second outdoor heat exchanger 23b functions as an evaporator at the time of startup, and mixed operation is performed to suppress the shortage of refrigeration oil in the compressor 1 at startup. It can be carried out.

以下、冷房運転、暖房運転、混在運転の順に、空気調和装置１の各運転時の動作について、適宜図１乃至図３を用いて説明する。尚、以下の説明では、図１乃至図３において、矢印は冷媒回路１００における冷媒の流れを示している。また、凝縮器として機能する熱交換器はハッチングを付し、蒸発器として機能する熱交換器は白抜きで図示している。さらには、電磁開閉弁２８および各膨張弁の開閉状態については、閉じている場合を黒塗りで、開いている場合を白抜きでそれぞれ図示している。 Hereinafter, the operation during each operation of the air conditioner 1 will be described with reference to FIGS. 1 to 3 as appropriate in the order of cooling operation, heating operation, and mixed operation. In the following description, the arrows in FIGS. 1 to 3 indicate the flow of the refrigerant in the refrigerant circuit 100. Further, the heat exchanger functioning as a condenser is hatched, and the heat exchanger functioning as an evaporator is illustrated in white. Furthermore, the open / close states of the electromagnetic open / close valve 28 and each expansion valve are shown in black when they are closed, and white when they are open.

＜冷房運転＞
まず、冷房運転における空気調和装置１の動作について図１を用いて説明する。冷房運転を行うとき、室外機制御手段２００のＣＰＵ２１０は、第１四方弁２２ａを実線で示す状態、すなわち、ポートａとポートｂとが連通するよう、また、ポートｃとポートｄとが連通するよう、切り替える。また、ＣＰＵ２１０は、第２四方弁２２ｂを実線で示す状態、すなわち、ポートｅとポートｆとが連通するよう、また、ポートｇとポートｈとが連通するよう、切り替える。これにより、第１室外熱交換器２３ａおよび第２室外熱交換器２３ｂが凝縮器として機能するとともに、室内熱交換器５１ａ〜５１ｃが蒸発器として機能する。また、ＣＰＵ２１０は、電磁開閉弁２８を開とする。 <Cooling operation>
First, operation | movement of the air conditioning apparatus 1 in air_conditionaing | cooling operation is demonstrated using FIG. When performing the cooling operation, the CPU 210 of the outdoor unit control means 200 is in a state where the first four-way valve 22a is indicated by a solid line, that is, the port a and the port b communicate with each other, and the port c and the port d communicate with each other. Switch. Further, the CPU 210 switches the state of the second four-way valve 22b as indicated by a solid line, that is, the port e and the port f communicate with each other and the port g and the port h communicate with each other. Thereby, while the 1st outdoor heat exchanger 23a and the 2nd outdoor heat exchanger 23b function as a condenser, the indoor heat exchangers 51a-51c function as an evaporator. Further, the CPU 210 opens the electromagnetic opening / closing valve 28.

冷媒回路１００が上記の状態となっているとき、圧縮機２１から吐出された高圧の冷媒は、吐出管４１を流れて第１吐出分管４１ａと第２吐出分管４１ｂとに分流する。第１吐出分管４１ａを流れる冷媒は第１四方弁２２ａに流入し、第１四方弁２２ａから第１接続配管４３ａを流れて第１室外熱交換器２３ａに流入する。第１室外熱交換器２３ａに流入した冷媒は、室外ファン２７の回転により室外機２の内部に取り込まれた外気と熱交換を行って凝縮する。第１室外熱交換器２３ａから流出した冷媒は第１液分管４４ａを流れ、全開とされている第１室外膨張弁２４ａを介して室外機液管４４に流れ、閉鎖弁２５を介して液管８に流入する。 When the refrigerant circuit 100 is in the above state, the high-pressure refrigerant discharged from the compressor 21 flows through the discharge pipe 41 and is divided into the first discharge branch pipe 41a and the second discharge branch pipe 41b. The refrigerant flowing through the first discharge branch pipe 41a flows into the first four-way valve 22a, flows from the first four-way valve 22a through the first connection pipe 43a, and flows into the first outdoor heat exchanger 23a. The refrigerant flowing into the first outdoor heat exchanger 23 a is condensed by exchanging heat with the outside air taken into the outdoor unit 2 by the rotation of the outdoor fan 27. The refrigerant flowing out from the first outdoor heat exchanger 23a flows through the first liquid distribution pipe 44a, flows into the outdoor unit liquid pipe 44 through the fully opened first outdoor expansion valve 24a, and flows through the closing valve 25 into the liquid pipe. 8 flows in.

一方、第２吐出分管４１ｂを流れる冷媒は開とされている電磁開閉弁２８を介して第２四方弁２２ｂに流入し、第２四方弁２２ｂから第２接続配管４３ｂを流れて第２室外熱交換器２３ｂに流入する。第２室外熱交換器２３ｂに流入した冷媒は、室外ファン２７の回転により室外機２の内部に取り込まれた外気と熱交換を行って凝縮する。第２室外熱交換器２３ｂから流出した冷媒は第２液分管４４ｂを流れ、全開とされている第２室外膨張弁２４ｂを介して室外機液管４４に流れ、閉鎖弁２５を介して液管８に流入する。 On the other hand, the refrigerant flowing through the second discharge distribution pipe 41b flows into the second four-way valve 22b through the opened electromagnetic on-off valve 28, and flows from the second four-way valve 22b through the second connection pipe 43b to the second outdoor heat. It flows into the exchanger 23b. The refrigerant flowing into the second outdoor heat exchanger 23 b is condensed by exchanging heat with the outside air taken into the outdoor unit 2 by the rotation of the outdoor fan 27. The refrigerant flowing out of the second outdoor heat exchanger 23b flows through the second liquid distribution pipe 44b, flows into the outdoor unit liquid pipe 44 through the fully opened second outdoor expansion valve 24b, and flows through the closing valve 25 into the liquid pipe. 8 flows in.

液管８を流れて分流し液管接続部５３ａ〜５３ｃを介して各室内機５ａ〜５ｃに流入した冷媒は、室内機液管７１ａ〜７１ｃを流れ、室内膨張弁５２ａ〜５２ｃを通過するときに減圧されて低圧の冷媒となる。室内機液管７１ａ〜７１ｃから室内熱交換器５１ａ〜５１ｃに流入した冷媒は、室内ファン５５ａ〜５５ｃの回転により室内機５ａ〜５ｃの内部に取り込まれた室内空気と熱交換を行って蒸発する。このように、室内熱交換器５１ａ〜５１ｃが蒸発器として機能し、室内熱交換器５１ａ〜５１ｃで冷媒と熱交換を行った室内空気が図示しない吹出口から室内に吹き出されることによって、室内機５ａ〜５ｃが設置された室内の冷房が行われる。 When the refrigerant flowing through the liquid pipe 8 is divided and flows into the indoor units 5a to 5c via the liquid pipe connecting portions 53a to 53c, the refrigerant flows through the indoor unit liquid pipes 71a to 71c and passes through the indoor expansion valves 52a to 52c. The pressure is reduced to a low-pressure refrigerant. The refrigerant flowing into the indoor heat exchangers 51a to 51c from the indoor unit liquid tubes 71a to 71c evaporates by exchanging heat with the indoor air taken into the indoor units 5a to 5c by the rotation of the indoor fans 55a to 55c. . In this way, the indoor heat exchangers 51a to 51c function as evaporators, and the indoor air that has exchanged heat with the refrigerant in the indoor heat exchangers 51a to 51c is blown into the room from a blower outlet (not shown), thereby The room where the machines 5a to 5c are installed is cooled.

室内熱交換器５１ａ〜５１ｃから流出した冷媒は、室内機ガス管７２ａ〜７２ｃを流れガス管接続部５４ａ〜５４ｃを介してガス管９に流入する。ガス管９を流れ閉鎖弁２６を介して室外機２に流入した冷媒は、室外機ガス管４５を流れて第１ガス分管４５ａと第２ガス分管４５ｂとに分流する。第１ガス分管４５ａに流れた冷媒は、第１四方弁２２ａ、第１吸入分管４２ａを流れて吸入管４２に流入し、圧縮機２１に吸入されて再び圧縮される。一方、第２ガス分管４５ｂに流れた冷媒は、第２四方弁２２ｂ、第２吸入分管４２ｂを流れて吸入管４２に流入し、圧縮機２１に吸入されて再び圧縮される。 The refrigerant that has flowed out of the indoor heat exchangers 51a to 51c flows through the indoor unit gas pipes 72a to 72c and flows into the gas pipe 9 through the gas pipe connection portions 54a to 54c. The refrigerant flowing through the gas pipe 9 and flowing into the outdoor unit 2 through the shut-off valve 26 flows through the outdoor unit gas pipe 45 and is divided into the first gas distribution pipe 45a and the second gas distribution pipe 45b. The refrigerant flowing into the first gas distribution pipe 45a flows through the first four-way valve 22a and the first suction distribution pipe 42a, flows into the suction pipe 42, is sucked into the compressor 21, and is compressed again. On the other hand, the refrigerant that has flowed into the second gas distribution pipe 45b flows through the second four-way valve 22b and the second suction distribution pipe 42b, flows into the suction pipe 42, is sucked into the compressor 21, and is compressed again.

以上説明したように冷媒回路１００を冷媒が循環することで、空気調和装置１の冷房運転が行われる。尚、低負荷状態で冷房運転を行っているとき、例えば、室内機５ａ〜５ｃの空調負荷が小さくかつ外気温度が低い状態で冷房運転を行っているときは、室外機２における凝縮能力が過剰となる場合がある。この場合は、例えば、第２室外膨張弁２４ｂを全閉とするとともに電磁開閉弁２８を閉として、第２室外熱交換器２３ｂに冷媒が流れなくすることで、室外機２における凝縮能力を低減させる。 As described above, the cooling operation of the air conditioner 1 is performed by circulating the refrigerant through the refrigerant circuit 100. When the cooling operation is performed in a low load state, for example, when the cooling operation is performed in a state where the air conditioning load of the indoor units 5a to 5c is small and the outside air temperature is low, the condensation capacity in the outdoor unit 2 is excessive. It may become. In this case, for example, the second outdoor expansion valve 24b is fully closed and the electromagnetic on-off valve 28 is closed so that the refrigerant does not flow to the second outdoor heat exchanger 23b, thereby reducing the condensation capacity in the outdoor unit 2. Let

＜暖房運転＞
次に、暖房運転における空気調和装置１の動作について図２を用いて説明する。暖房運転を行うとき、ＣＰＵ２１０は、第１四方弁２２ａを実線で示す状態、すなわち、第１四方弁２２ａのポートａとポートｄとが連通するよう、また、ポートｂとポートｃとが連通するよう、切り替える。また、ＣＰＵ２１０は、第２四方弁２２ｂが実線で示す状態、すなわち、第２四方弁２２ｂのポートｅとポートｈとが連通するよう、また、ポートｆとポートｇとが連通するよう、切り替える。これにより、第１室外熱交換器２３ａおよび第２室外熱交換器２３ｂが蒸発器として機能するとともに、室内熱交換器５１ａ〜５１ｃが凝縮器として機能する。また、ＣＰＵ２１０は、電磁開閉弁２８を開とする。 <Heating operation>
Next, operation | movement of the air conditioning apparatus 1 in heating operation is demonstrated using FIG. When performing the heating operation, the CPU 210 is in a state where the first four-way valve 22a is indicated by a solid line, that is, the port a and the port d of the first four-way valve 22a communicate with each other, and the port b and the port c communicate with each other. Switch. Further, the CPU 210 switches the state where the second four-way valve 22b is indicated by a solid line, that is, the port e and the port h of the second four-way valve 22b are communicated, and the port f and the port g are communicated. Thereby, while the 1st outdoor heat exchanger 23a and the 2nd outdoor heat exchanger 23b function as an evaporator, the indoor heat exchangers 51a-51c function as a condenser. Further, the CPU 210 opens the electromagnetic opening / closing valve 28.

冷媒回路１００が上記の状態となっているとき、圧縮機２１から吐出された高圧の冷媒は、吐出管４１を流れて第１吐出分管４１ａと第２吐出分管４１ｂとに分流する。第１吐出分管４１ａを流れる冷媒は第１四方弁２２ａに流入し、第１四方弁２２ａから第１ガス分管４５ａを流れて室外機ガス管４５に流入する。一方、第２吐出分管４１ｂを流れる冷媒は開とされている電磁開閉弁２８を介して第２四方弁２２ｂに流入し、第２四方弁２２ｂから第２ガス分管４５ｂを流れて室外機ガス管４５に流入する。 When the refrigerant circuit 100 is in the above state, the high-pressure refrigerant discharged from the compressor 21 flows through the discharge pipe 41 and is divided into the first discharge branch pipe 41a and the second discharge branch pipe 41b. The refrigerant flowing through the first discharge distribution pipe 41a flows into the first four-way valve 22a, flows from the first four-way valve 22a through the first gas distribution pipe 45a, and flows into the outdoor unit gas pipe 45. On the other hand, the refrigerant flowing through the second discharge distribution pipe 41b flows into the second four-way valve 22b through the opened electromagnetic on-off valve 28, and flows from the second four-way valve 22b through the second gas distribution pipe 45b to the outdoor unit gas pipe. 45.

室外機ガス管４５に流入した冷媒は、閉鎖弁２６を介してガス管９を流れて分流し、ガス管接続部５４ａ〜５４ｃを介して各室内機５ａ〜５ｃに流入する。各室内機５ａ〜５ｃに流入した冷媒は、室内機ガス管７２ａ〜７２ｂを流れて室内熱交換器５１ａ〜５１ｂに流入し、室内ファン５５ａ〜５５ｃの回転により室内機５ａ〜５ｃの内部に取り込まれた室内空気と熱交換を行って凝縮する。このように、室内熱交換器５１ａ〜５１ｃが凝縮器として機能し、室内熱交換器５１ａ〜５１ｃで冷媒と熱交換を行った室内空気が図示しない吹出口から室内に吹き出されることによって、室内機５ａ〜５ｃが設置された室内の暖房が行われる。 The refrigerant that has flowed into the outdoor unit gas pipe 45 flows through the gas pipe 9 via the shut-off valve 26 and is divided, and then flows into the indoor units 5a to 5c through the gas pipe connection portions 54a to 54c. The refrigerant flowing into the indoor units 5a to 5c flows through the indoor unit gas pipes 72a to 72b, flows into the indoor heat exchangers 51a to 51b, and is taken into the indoor units 5a to 5c by the rotation of the indoor fans 55a to 55c. Heat exchanges with the room air and condenses. As described above, the indoor heat exchangers 51a to 51c function as condensers, and the indoor air that has exchanged heat with the refrigerant in the indoor heat exchangers 51a to 51c is blown into the room from a blowout port (not shown), thereby The room where the machines 5a to 5c are installed is heated.

室内熱交換器５１ａ〜５１ｃから流出した冷媒は室内機液管７１ａ〜７１ｃを流れ、室内膨張弁５２ａ〜５２ｃを通過して減圧される。減圧された冷媒は、液管接続部５３ａ〜５３ｃを介して液管８に流入する。液管８を流れ閉鎖弁２５を介して室外機２に流入した冷媒は、室外機液管４４を流れて第１液分管４４ａと第２液分管４４ｂとに分流する。 The refrigerant flowing out of the indoor heat exchangers 51a to 51c flows through the indoor unit liquid pipes 71a to 71c, passes through the indoor expansion valves 52a to 52c, and is decompressed. The decompressed refrigerant flows into the liquid pipe 8 through the liquid pipe connecting portions 53a to 53c. The refrigerant flowing through the liquid pipe 8 and flowing into the outdoor unit 2 through the shut-off valve 25 flows through the outdoor unit liquid pipe 44 and is divided into the first liquid distribution pipe 44a and the second liquid distribution pipe 44b.

第１液分管４４ａに流入した冷媒は、第１室外膨張弁２４ａを通過するときに更に減圧される。第１室外膨張弁２４ａから第１室外熱交換器２３ａに流入した冷媒は、室外ファン２７の回転により室外機２の内部に取り込まれた外気と熱交換を行って蒸発する。第１室外熱交換器２３ａから流出した冷媒は、第１接続配管４３ａ、第１四方弁２２ａ、第１吸入分管４２ａを流れて、吸入管４２に流入する。 The refrigerant flowing into the first liquid distribution pipe 44a is further decompressed when passing through the first outdoor expansion valve 24a. The refrigerant flowing into the first outdoor heat exchanger 23 a from the first outdoor expansion valve 24 a evaporates by exchanging heat with the outside air taken into the outdoor unit 2 by the rotation of the outdoor fan 27. The refrigerant that has flowed out of the first outdoor heat exchanger 23a flows through the first connection pipe 43a, the first four-way valve 22a, and the first suction distribution pipe 42a, and then flows into the suction pipe 42.

一方、第２液分管４４ｂに流入した冷媒は、第２室外膨張弁２４ｂを通過するときに更に減圧される。第２室外膨張弁２４ｂから第２室外熱交換器２３ｂに流入した冷媒は、室外ファン２７の回転により室外機２の内部に取り込まれた外気と熱交換を行って蒸発する。第２室外熱交換器２３ｂから流出した冷媒は、第２接続配管４３ｂ、第２四方弁２２ｂ、第２吸入分管４２ｂを流れて、吸入管４２に流入する。そして、吸入管４２に流入した冷媒は、圧縮機２１に吸入されて再び圧縮される。 On the other hand, the refrigerant flowing into the second liquid distribution pipe 44b is further depressurized when passing through the second outdoor expansion valve 24b. The refrigerant flowing into the second outdoor heat exchanger 23b from the second outdoor expansion valve 24b evaporates by exchanging heat with the outside air taken into the outdoor unit 2 by the rotation of the outdoor fan 27. The refrigerant that has flowed out of the second outdoor heat exchanger 23b flows through the second connection pipe 43b, the second four-way valve 22b, and the second suction distribution pipe 42b and flows into the suction pipe 42. Then, the refrigerant flowing into the suction pipe 42 is sucked into the compressor 21 and compressed again.

以上説明したように冷媒回路１００を冷媒が循環することで、空気調和装置１の暖房運転が行われる。尚、低負荷状態で暖房運転を行っているとき、例えば、室内機５ａ〜５ｃの空調負荷が小さくかつ外気温度が高い状態で暖房運転を行っているときは、室外機２における蒸発能力が過剰となる場合がある。この場合は、例えば、第２室外膨張弁２４ｂを全閉として、第２室外熱交換器２３ｂに冷媒が流れなくすることで、室外機２における蒸発能力を低減させる。 As described above, when the refrigerant circulates through the refrigerant circuit 100, the air-conditioning apparatus 1 is heated. When the heating operation is performed in a low load state, for example, when the heating operation is performed in a state where the air conditioning load of the indoor units 5a to 5c is small and the outside air temperature is high, the evaporation capacity in the outdoor unit 2 is excessive. It may become. In this case, for example, the second outdoor expansion valve 24b is fully closed to prevent the refrigerant from flowing into the second outdoor heat exchanger 23b, thereby reducing the evaporation capability of the outdoor unit 2.

背景技術で説明した特許文献１に記載の空気調和装置では、本実施形態の空気調和装置１における電磁開閉弁２８に代えて、図４に示すように、四方弁３２０ａと第３の分岐点３８０とを接続する配管（本実施形態における第２ガス分管４５ｂに相当）に逆止弁３４０が設けられ、この逆止弁３４０は第３の分岐点３８０から四方弁３２０ｂへの冷媒の流れのみ許容するように配置される。 In the air conditioner described in Patent Document 1 described in the background art, instead of the electromagnetic on-off valve 28 in the air conditioner 1 of the present embodiment, as shown in FIG. 4, a four-way valve 320a and a third branch point 380 are provided. Is connected to the pipe (corresponding to the second gas distribution pipe 45b in the present embodiment), and the check valve 340 allows only the flow of refrigerant from the third branch point 380 to the four-way valve 320b. To be arranged.

この空気調和装置１が冷房運転を行うときは、室内機から室外機に流入した冷媒が、第３の分岐点３８０→四方弁３２０ｂ→圧縮機３１０と流れるので、逆止弁３４０が冷媒の流れを妨げることがない。しかし、空気調和装置が暖房運転を行うときは、圧縮機２１から吐出され、四方弁３２０ｂから第３の分岐点３４０へと流れる冷媒が、逆止弁３４０で堰き止められる。 When the air conditioner 1 performs a cooling operation, the refrigerant flowing from the indoor unit to the outdoor unit flows from the third branch point 380 to the four-way valve 320b to the compressor 310, and thus the check valve 340 flows the refrigerant. Will not be disturbed. However, when the air conditioner performs the heating operation, the refrigerant discharged from the compressor 21 and flowing from the four-way valve 320b to the third branch point 340 is blocked by the check valve 340.

このため、冷媒および冷媒とともに圧縮機３１０から吐出された冷凍機油は、第１の分岐点３６０から四方弁３２０ｂを経て逆止弁３４０までの間の配管や機器に滞留する。そして、この状態が継続すれば、上述した箇所に滞留する冷凍機油が圧縮機３１０に戻らないので、圧縮機３１０で冷凍機油が不足する虞があった。 For this reason, the refrigeration oil discharged from the compressor 310 together with the refrigerant and the refrigerant stays in the piping and equipment between the first branch point 360 and the check valve 340 through the four-way valve 320b. And if this state continues, since the refrigerating machine oil staying in the above-mentioned location does not return to the compressor 310, there is a possibility that the refrigerating machine oil is insufficient in the compressor 310.

このとき、一旦暖房運転を停止し室外熱交換器３３０ａと室外熱交換器３３０ｂとを凝縮器として機能させるよう、つまり、空気調和装置が冷房運転となるように、四方弁３２０ａと四方弁３２０ｂとをそれぞれ切り替えて油戻し運転を行えば、圧縮機３１０の冷凍機油不足は解消する。しかし、油戻し運転から暖房運転に復帰すれば、再度上述した箇所に冷凍機油が滞留するので、暖房運転と油戻し運転とを繰り返す頻度が多くなり、暖房運転が頻繁に中断されて使用者の快適性を損なう虞があった。 At this time, the four-way valve 320a and the four-way valve 320b are set so that the heating operation is temporarily stopped and the outdoor heat exchanger 330a and the outdoor heat exchanger 330b function as condensers, that is, the air conditioner is in a cooling operation. When the oil return operation is performed by switching each of the above, the shortage of refrigeration oil in the compressor 310 is resolved. However, if the oil return operation is returned to the heating operation, the refrigeration oil stays in the above-mentioned location again, so that the frequency of repeating the heating operation and the oil return operation increases, and the heating operation is frequently interrupted and the user's There was a risk of impairing comfort.

これに対し、本発明の空気調和装置１では、第２吐出分管４１ｂに電磁開閉弁２８を設け、暖房運転時に電磁開閉弁２８を開としている。このため、暖房運転時に圧縮機２１から吐出された冷媒が、吐出管４１→第２吐出分管４１ｂ→第２四方弁２２ｂ→第２ガス分管４５ｂ→室外機ガス管４５と流れる際に途中で堰き止められることがなく、冷媒が室内機５ａ〜５ｃに循環して再び室外機２に戻って圧縮機２１に吸入される。従って、冷媒とともに圧縮機２１から吐出された冷凍機油も途中で滞留せずに室外機２に戻って圧縮機２１に吸入されるので、圧縮機２１における冷凍機油不足が抑制され、また、油戻し運転により暖房運転が頻繁に中断されることを防止できる。 On the other hand, in the air conditioning apparatus 1 of the present invention, the electromagnetic opening / closing valve 28 is provided in the second discharge distribution pipe 41b, and the electromagnetic opening / closing valve 28 is opened during the heating operation. For this reason, the refrigerant discharged from the compressor 21 during the heating operation is blocked on the way when it flows from the discharge pipe 41 → the second discharge distribution pipe 41b → the second four-way valve 22b → the second gas distribution pipe 45b → the outdoor unit gas pipe 45. Without being stopped, the refrigerant circulates in the indoor units 5a to 5c, returns to the outdoor unit 2 again, and is sucked into the compressor 21. Accordingly, the refrigerating machine oil discharged from the compressor 21 together with the refrigerant returns to the outdoor unit 2 and is sucked into the compressor 21 without staying on the way, so that the shortage of refrigerating machine oil in the compressor 21 is suppressed, and the oil return It is possible to prevent the heating operation from being frequently interrupted by the operation.

＜混在運転＞
次に、混在運転における空気調和装置１の動作について図３を用いて説明する。混在運転は、低外気温度（０℃以下）で空気調和装置１を起動するときに、圧縮機１の吐出圧力上昇により発生する冷媒寝込みの抑制や、圧縮機１から冷媒とともに吐出される冷凍機油を早く圧縮機１に戻すことで、圧縮機１で冷凍機油が不足することを防止するために行うものである。尚、冷媒寝込みの解消や冷凍機油が圧縮機１に回収できていると考えられる条件、例えば、圧縮機１が起動してから所定時間（例えば、３分）が経過した、圧縮機１の吐出過熱度が所定値（例えば、１０℃）以上となった、等の条件が成立すれば、空気調和装置１は混在運転を停止し、冷房運転あるいは暖房運転を開始する。 <Mixed operation>
Next, operation | movement of the air conditioning apparatus 1 in mixed operation is demonstrated using FIG. In the mixed operation, when the air-conditioning apparatus 1 is started at a low outside air temperature (0 ° C. or less), the refrigerant stagnation caused by the increase in the discharge pressure of the compressor 1 or the refrigerating machine oil discharged from the compressor 1 together with the refrigerant is used. Is performed in order to prevent the compressor 1 from running out of refrigerating machine oil by quickly returning to the compressor 1. It should be noted that the discharge of the compressor 1 after elapse of a predetermined time (for example, 3 minutes) after the start of the compressor 1, for example, conditions under which refrigerant stagnation is eliminated or refrigeration oil can be recovered in the compressor 1 If the condition that the degree of superheat becomes a predetermined value (for example, 10 ° C.) or more is satisfied, the air conditioner 1 stops the mixed operation and starts the cooling operation or the heating operation.

混在運転を行うとき、ＣＰＵ２１０は、第１四方弁２２ａを実線で示す状態、すなわち、ポートａとポートｂとが連通するよう、また、ポートｃとポートｄとが連通するよう、切り替える。また、ＣＰＵ２１０は、第２四方弁２２ｂが実線で示す状態、すなわち、第２四方弁２２ｂのポートｅとポートｈとが連通するよう、また、ポートｆとポートｇとが連通するよう、切り替える。これにより、第１室外熱交換器２３ａが凝縮器として機能するとともに、第２室外熱交換器２３ｂが蒸発器として機能する。 When performing the mixed operation, the CPU 210 switches the state where the first four-way valve 22a is indicated by a solid line, that is, the port a and the port b communicate with each other and the port c and the port d communicate with each other. Further, the CPU 210 switches the state where the second four-way valve 22b is indicated by a solid line, that is, the port e and the port h of the second four-way valve 22b are communicated, and the port f and the port g are communicated. Thereby, while the 1st outdoor heat exchanger 23a functions as a condenser, the 2nd outdoor heat exchanger 23b functions as an evaporator.

また、ＣＰＵ２１０は、電磁開閉弁２８を閉とするとともに、室内機５ａ〜５ｃの図示しない室内機制御手段に対し室内膨張弁５２ａ〜５２ｃを全閉とする旨の制御信号を送信する。この制御信号を受信した室内機制御手段は、室内膨張弁５２ａ〜５２ｃを全閉とする。室内膨張弁５２ａ〜５２ｃを全閉とすることによって、混在運転時は室内機５ａ〜５ｃに冷媒が流れない。 Further, the CPU 210 closes the electromagnetic opening / closing valve 28 and transmits a control signal for fully closing the indoor expansion valves 52a to 52c to indoor unit control means (not shown) of the indoor units 5a to 5c. The indoor unit control means that has received this control signal fully closes the indoor expansion valves 52a to 52c. By fully closing the indoor expansion valves 52a to 52c, the refrigerant does not flow to the indoor units 5a to 5c during the mixed operation.

冷媒回路１００が上記の状態となっているとき、圧縮機２１から吐出された高圧の冷媒は、吐出管４１を流れて第１吐出分管４１ａと第２吐出分管４１ｂとに分流する。第１吐出分管４１ａを流れる冷媒は第１四方弁２２ａに流入し、第１四方弁２２ａから第１接続配管４３ａを流れて第１室外熱交換器２３ａに流入する。第１室外熱交換器２３ａに流入した冷媒は、室外ファン２７の回転により室外機２の内部に取り込まれた外気と熱交換を行って凝縮する。 When the refrigerant circuit 100 is in the above state, the high-pressure refrigerant discharged from the compressor 21 flows through the discharge pipe 41 and is divided into the first discharge branch pipe 41a and the second discharge branch pipe 41b. The refrigerant flowing through the first discharge branch pipe 41a flows into the first four-way valve 22a, flows from the first four-way valve 22a through the first connection pipe 43a, and flows into the first outdoor heat exchanger 23a. The refrigerant flowing into the first outdoor heat exchanger 23 a is condensed by exchanging heat with the outside air taken into the outdoor unit 2 by the rotation of the outdoor fan 27.

第１室外熱交換器２３ａから流出した冷媒は第１液分管４４ａを流れ、全開とされている第１室外膨張弁２４ａを介して第２液分管４４ｂに流れる。第２液分管４４ｂを流れる冷媒は、第２室外膨張弁２４ｂを通過する際に減圧されて、第２室外熱交換器２３ｂに流入する。 The refrigerant that has flowed out of the first outdoor heat exchanger 23a flows through the first liquid distribution pipe 44a, and then flows into the second liquid distribution pipe 44b through the fully opened first outdoor expansion valve 24a. The refrigerant flowing through the second liquid distribution pipe 44b is decompressed when passing through the second outdoor expansion valve 24b, and flows into the second outdoor heat exchanger 23b.

第２室外熱交換器２３ｂに流入した冷媒は、室外ファン２７の回転により室外機２の内部に取り込まれた外気と熱交換を行って蒸発する。第２室外熱交換器２３ｂから流出した冷媒は、第２接続配管４３ｂ、第２四方弁２２ｂ、第２吸入分管４２ｂ、吸入管４２と流れて圧縮機１に吸入され、再び圧縮される。 The refrigerant flowing into the second outdoor heat exchanger 23 b evaporates by exchanging heat with the outside air taken into the outdoor unit 2 by the rotation of the outdoor fan 27. The refrigerant flowing out of the second outdoor heat exchanger 23b flows through the second connection pipe 43b, the second four-way valve 22b, the second suction distribution pipe 42b, and the suction pipe 42, is sucked into the compressor 1, and is compressed again.

一方、吐出管４１から第２吐出分管４１ｂに流入した冷媒は、閉とされている電磁開閉弁２８によって堰き止められ、第２吐出分管４１ｂから第２四方弁２２ｂへと流れない。つまり、混在運転で第２室外熱交換器２３ｂを蒸発器として機能させているときに、圧縮機１から吐出された冷媒の一部が、第２吐出分管４１ｂ→第２四方弁２２ｂ→第２ガス分管４５ｂ→第１ガス分管４５ａ→第１四方弁２２ａ→第１吸入分管４２ａ→吸入管４２、と流れて圧縮機１に吸入される冷媒のショートカットが発生しない。 On the other hand, the refrigerant that has flowed into the second discharge branch pipe 41b from the discharge pipe 41 is blocked by the closed electromagnetic on-off valve 28, and does not flow from the second discharge branch pipe 41b to the second four-way valve 22b. That is, when the second outdoor heat exchanger 23b is functioning as an evaporator in the mixed operation, a part of the refrigerant discharged from the compressor 1 is second discharge branch pipe 41b → second four-way valve 22b → second. The flow of the gas distribution pipe 45b → the first gas distribution pipe 45a → the first four-way valve 22a → the first intake distribution pipe 42a → the intake pipe 42 does not cause a shortcut to the refrigerant sucked into the compressor 1.

以上説明したように、本発明の空気調和装置は、複数の室外熱交換器のうち少なくとも１つの室外熱交換器を蒸発器として機能させ、残りの室外熱交換器を凝縮器として機能させるときに、開閉手段が設けられた吐出分管あるいは開閉手段が設けられたガス分管が設けられた室外熱交換器ユニットの室外熱交換器を蒸発器として機能させるよう当該四方弁を切り替えるとともに、開閉手段を閉じる。これにより、冷媒のショートカットを防止できる。また、複数の室外熱交換器を全て蒸発器として機能させるとき、つまり、暖房運転を行うときは、開閉手段を開くことによって冷凍機油の滞留を防止できるので、圧縮機の冷凍機油不足や油戻し運転による暖房運転の頻繁な中断を防止できる。 As described above, the air-conditioning apparatus of the present invention allows at least one outdoor heat exchanger of a plurality of outdoor heat exchangers to function as an evaporator and the remaining outdoor heat exchangers to function as a condenser. The four-way valve is switched so that the outdoor heat exchanger of the outdoor heat exchanger unit provided with the discharge distribution pipe provided with the opening / closing means or the gas distribution pipe provided with the opening / closing means functions as an evaporator, and the opening / closing means is closed. . Thereby, the shortcut of a refrigerant | coolant can be prevented. In addition, when all the outdoor heat exchangers function as evaporators, that is, when heating operation is performed, stagnation of refrigeration oil can be prevented by opening the opening / closing means. It is possible to prevent frequent interruption of heating operation due to operation.

尚、以上説明した実施形態では、電磁開閉弁２８を第２吐出分管４１ｂに設け、混在運転を行うときは、第２室外熱交換器２３ｂが蒸発器として機能するよう第２四方弁２２ｂを切り替える場合について説明したが、電磁開閉弁２８を第１吐出分管４１ａに設け、混在運転を行うときは、第１室外熱交換器２３ａが蒸発器として機能するよう第１四方弁２２ａを切り替えるようにしてもよい。 In the embodiment described above, the electromagnetic open / close valve 28 is provided in the second discharge distribution pipe 41b, and when the mixed operation is performed, the second four-way valve 22b is switched so that the second outdoor heat exchanger 23b functions as an evaporator. As described above, when the electromagnetic on-off valve 28 is provided in the first discharge distribution pipe 41a and mixed operation is performed, the first four-way valve 22a is switched so that the first outdoor heat exchanger 23a functions as an evaporator. Also good.

また、電磁開閉弁２８を第２吐出分管４１ｂではなく第２ガス分管４５ｂに設けても、本発明の奏する効果を得ることができる。一般的に、第２吐出分管４１ｂの配管径に比べて第２ガス分管４５ｂの配管径の方が大きいため、電磁開閉弁２８を第２ガス分管４５ｂに設ける場合は、電磁開閉弁２８を第２吐出分管４１ｂに設ける場合と比べて、電磁開閉弁２８が大型化しコストアップとなるが、その反面、電磁開閉弁２８を第２ガス分管４５ｂに設けると、第２四方弁２２ｂの前後（ポートｅとポートｇ）の圧力差がつきやすく、第２四方弁２２ｂの切り替えが行いやすいという効果がある。 Further, even when the electromagnetic opening / closing valve 28 is provided not in the second discharge distribution pipe 41b but in the second gas distribution pipe 45b, the effect of the present invention can be obtained. Generally, the pipe diameter of the second gas distribution pipe 45b is larger than the pipe diameter of the second discharge distribution pipe 41b. Therefore, when the electromagnetic opening / closing valve 28 is provided in the second gas distribution pipe 45b, the electromagnetic opening / closing valve 28 is not provided. Compared to the case where the solenoid valve 28 is provided in the two discharge distribution pipes 41b, the size of the electromagnetic valve 28 is increased and the cost is increased. On the other hand, if the solenoid valve 28 is provided in the second gas distribution pipe 45b, the solenoid valve 28 There is an effect that the pressure difference between e and port g) is likely to occur and the second four-way valve 22b is easily switched.

１空気調和装置
２室外機
５ａ〜５ｃ室内機
８液管
９ガス管
２０室外機冷媒回路
２０ａ第１室外熱交換器ユニット
２０ｂ第２室外熱交換器ユニット
２１圧縮機
２２ａ第１四方弁
２２ｂ第２四方弁
２３ａ第１室外熱交換器
２３ｂ第２室外熱交換器
４１吐出管
４１ａ第１吐出分管
４１ｂ第２吐出分管
４２吸入管
４２ａ第１吸入分管
４２ｂ第２吸入分管
４４室外機液管
４４ａ第１液分管
４４ｂ第２液分管
４５室外機ガス管
４５ａ第１ガス分管
４５ｂ第２ガス分管
５１ａ〜５１ｃ室内熱交換器
１００冷媒回路
２００室外機制御部
２１０ＣＰＵ DESCRIPTION OF SYMBOLS 1 Air conditioning apparatus 2 Outdoor unit 5a-5c Indoor unit 8 Liquid pipe 9 Gas pipe 20 Outdoor unit refrigerant circuit 20a 1st outdoor heat exchanger unit 20b 2nd outdoor heat exchanger unit 21 Compressor 22a 1st four-way valve 22b 2nd Four-way valve 23a First outdoor heat exchanger 23b Second outdoor heat exchanger 41 Discharge pipe 41a First discharge distribution pipe 41b Second discharge distribution pipe 42 Suction pipe 42a First suction distribution pipe 42b Second suction distribution pipe 44 Outdoor unit liquid pipe 44a First Liquid distribution pipe 44b Second liquid distribution pipe 45 Outdoor unit gas pipe 45a First gas distribution pipe 45b Second gas distribution pipe 51a to 51c Indoor heat exchanger 100 Refrigerant circuit 200 Outdoor unit control unit 210 CPU

Claims

An air conditioner having an outdoor unit and an indoor unit, wherein the outdoor unit and the indoor unit are connected by a gas pipe and a liquid pipe,
The outdoor unit includes a compressor, a discharge pipe connected to a refrigerant discharge side of the compressor, a suction pipe connected to a refrigerant suction side of the compressor, an outdoor unit gas pipe, and an indoor unit liquid pipe A plurality of outdoor heat exchanger units;
The outdoor heat exchanger unit includes an outdoor heat exchanger, a four-way valve, a discharge branch pipe connecting the first port of the four-way valve and the discharge pipe, a second port of the four-way valve, and the outdoor heat. A connection pipe connecting one refrigerant inlet / outlet of the exchanger, a suction distribution pipe connecting the third port of the four-way valve and the suction pipe, a fourth port of the four-way valve, and the outdoor unit gas pipe; And a liquid distribution pipe connecting the other refrigerant inlet / outlet of the outdoor heat exchanger and the outdoor unit liquid pipe,
An air conditioner characterized in that an opening / closing means is provided in either one of the discharge distribution pipe or the gas distribution pipe of at least one outdoor heat exchanger unit among the plurality of outdoor heat exchanger units.