JP2018132218A - Air conditioning device - Google Patents

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JP2018132218A
JP2018132218A JP2017024456A JP2017024456A JP2018132218A JP 2018132218 A JP2018132218 A JP 2018132218A JP 2017024456 A JP2017024456 A JP 2017024456A JP 2017024456 A JP2017024456 A JP 2017024456A JP 2018132218 A JP2018132218 A JP 2018132218A
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refrigerant
superheat degree
refrigerant superheat
indoor
degree
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JP6930127B2 (en
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秀哉 田村
Hideya Tamura
秀哉 田村
真寿 渡邊
Masatoshi Watanabe
真寿 渡邊
真也 浅野
Shinya Asano
真也 浅野
隆志 木村
Takashi Kimura
隆志 木村
廣太郎 戸矢
Kotaro Toya
廣太郎 戸矢
由樹 田中
Yoshiki Tanaka
由樹 田中
裕樹 渡部
Hiroki Watabe
裕樹 渡部
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Fujitsu General Ltd
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Abstract

PROBLEM TO BE SOLVED: To provide an air conditioning device capable of exhibiting a sufficient cooling capacity in each indoor unit by allowing a sufficient amount of refrigerant to flow into the indoor unit which cannot exhibit a cooling capacity.SOLUTION: A CPU 210 determines whether a target refrigerant superheating degree SHg is an upper limit refrigerant superheating degree SHu or more, or not. When the target refrigerant superheating degree SHg is the upper limit refrigerant superheating degree SHu or more, the upper limit refrigerant superheating degree SHu is applied as the target refrigerant superheating degree SHg, and when the target refrigerant superheating degree SHg is not the upper limit refrigerant superheating degree SHu or more, whether the target refrigerant superheating degree SHg is less than a lower limit refrigerant superheating degree SHl or not is determined. When the target refrigerant superheating degree SHg is not less than the lower limit refrigerant superheating degree SHl, a present target refrigerant superheating degree SHg is used as it is, and when the target refrigerant superheating degree SHg is less than the lower limit refrigerant superheating degree SHl, the lower limit refrigerant superheating degree SHl is applied as the target refrigerant superheating degree SHg.SELECTED DRAWING: Figure 3

Description

本発明は、少なくとも１台の室外機に複数台の室内機が冷媒配管で接続された空気調和装置に関する。   The present invention relates to an air conditioner in which a plurality of indoor units are connected to a refrigerant pipe by at least one outdoor unit.

従来、少なくとも１台の室外機に複数台の室内機が液管とガス管で接続された空気調和装置で冷房運転を行うときは、蒸発器として機能する各室内機の室内熱交換器の冷媒出口側における冷媒過熱度が、予め定められた基準値（例えば、２ｄｅｇ）となるように、各室内機に対応する膨張弁の開度が調整される（例えば、特許文献１参照）。   Conventionally, when performing cooling operation with an air conditioner in which a plurality of indoor units are connected to at least one outdoor unit by liquid pipes and gas pipes, the refrigerant of the indoor heat exchanger of each indoor unit that functions as an evaporator The opening degree of the expansion valve corresponding to each indoor unit is adjusted so that the refrigerant superheat degree on the outlet side becomes a predetermined reference value (for example, 2 deg) (for example, see Patent Document 1).

具体的には、室内機毎に、室内熱交換器の冷媒入口側における冷媒温度（以降、熱交入口温度と記載）と室内熱交換器の冷媒出口側における冷媒温度（以降、熱交出口温度と記載）を検出し、熱交出口温度から熱交入口温度を減じて、各室内機の冷媒過熱度が求められる。   Specifically, for each indoor unit, the refrigerant temperature on the refrigerant inlet side of the indoor heat exchanger (hereinafter referred to as heat exchange inlet temperature) and the refrigerant temperature on the refrigerant outlet side of the indoor heat exchanger (hereinafter referred to as heat exchange outlet temperature). And the heat exchange inlet temperature is subtracted from the heat exchange outlet temperature, and the refrigerant superheat degree of each indoor unit is obtained.

そして、求めた各室内機の冷媒過熱度が上述した基準値となるように、各室内機に対応する膨張弁の開度が調整される。具体的には、ある室内機において求めた冷媒過熱度が基準値より大きい場合は、当該室内機に対応する膨張弁の開度が大きくされる。膨張弁の開度が大きくされることで、当該室内機の室内熱交換器に流入する冷媒量が増えて冷媒過熱度が低下する。一方、ある室内機において求めた冷媒過熱度が基準値より小さい場合は、当該室内機に対応する膨張弁の開度が小さくされる。膨張弁の開度が小さくされることで、当該室内機の室内熱交換器に流入する冷媒量が減って冷媒過熱度が上昇する。   And the opening degree of the expansion valve corresponding to each indoor unit is adjusted so that the obtained refrigerant superheat degree of each indoor unit becomes the reference value described above. Specifically, when the degree of refrigerant superheat obtained in a certain indoor unit is larger than the reference value, the opening degree of the expansion valve corresponding to the indoor unit is increased. By increasing the opening degree of the expansion valve, the amount of refrigerant flowing into the indoor heat exchanger of the indoor unit increases, and the degree of refrigerant superheat decreases. On the other hand, when the refrigerant superheat degree obtained in a certain indoor unit is smaller than the reference value, the opening degree of the expansion valve corresponding to the indoor unit is reduced. By reducing the opening of the expansion valve, the amount of refrigerant flowing into the indoor heat exchanger of the indoor unit is reduced and the degree of refrigerant superheat is increased.

特開昭６３−２９１５９号公報JP 63-29159 A

上述した空気調和装置で冷房運転を行う場合に、室外機と各室内機の設置状態によっては、特定の室内機に流入する冷媒量が少なくなる場合がある。例えば、各室内機の設置場所が室外機の設置場所より高い位置であり、かつ、各室内機の設置場所に高低差がある場合は、上方に設置された室内機に冷媒が流れにくくなるので、当該室内機に流入する冷媒量が他の室内機と比べて少なくなる。冷房運転時は、室外機から各室内機へ向かって流れる冷媒が、室外機の室外熱交換器で凝縮されて液冷媒となり、液冷媒を重力に逆らって室外機より上方に設置された室内機に流さなければならないためである。   When performing the cooling operation with the air conditioner described above, the amount of refrigerant flowing into a specific indoor unit may be reduced depending on the installation state of the outdoor unit and each indoor unit. For example, if the installation location of each indoor unit is higher than the installation location of the outdoor unit and there is a height difference in the installation location of each indoor unit, the refrigerant will not easily flow into the indoor unit installed above. The amount of refrigerant flowing into the indoor unit is smaller than that of other indoor units. During cooling operation, the refrigerant flowing from the outdoor unit toward each indoor unit is condensed in the outdoor heat exchanger of the outdoor unit to become liquid refrigerant, and the indoor unit is installed above the outdoor unit against gravity. This is because it must be washed away.

また、各室内機の設置場所と室外機の設置場所がほぼ同じ高さであっても、各室内機と室外機の距離が異なれば、室外機から遠い場所に配置される室内機に流入する冷媒量は室外機に近い場所に配置される室内機に流入する冷媒量と比べて少なくなる。室外機から遠い場所に設置される室内機は、当該室内機と室外機を接続する冷媒配管の長さが他の室内機と比べて長くなり、他の室内機と比べて冷媒配管による圧力損失が大きくなるためである。   In addition, even if the installation location of each indoor unit and the installation location of the outdoor unit are almost the same height, if the distance between each indoor unit and the outdoor unit is different, it will flow into the indoor unit located far from the outdoor unit The amount of refrigerant is smaller than the amount of refrigerant flowing into the indoor unit disposed near the outdoor unit. In indoor units installed at locations far from outdoor units, the length of the refrigerant pipe connecting the indoor unit and the outdoor unit is longer than that of other indoor units, and the pressure loss due to the refrigerant piping is higher than that of other indoor units. This is because of the increase.

このように、特定の室内機に流入する冷媒量が少なくなる各室内機の設置状態となっているときに、室内機間の高低差が大きい（例えば、５０ｍ以上の高低差がある）場合の一番上方に設置された室内機や、室外機から一番遠い場所に設置されている室内機と室外機の距離が大きい（例えば、５０ｍ以上離れている）場合は、当該室内機に流入する冷媒量が著しく減少して冷媒不足となり、使用者が要求する冷房能力を発揮できない恐れがあった。   Thus, when it is in the installation state of each indoor unit in which the refrigerant | coolant amount which flows into a specific indoor unit becomes small, the height difference between indoor units is large (for example, there exists a height difference of 50 m or more). When the indoor unit installed at the uppermost position or the distance between the indoor unit installed farthest from the outdoor unit and the outdoor unit is large (for example, 50 m or more), it flows into the indoor unit. There was a possibility that the amount of the refrigerant would be significantly reduced and the refrigerant would be insufficient, so that the cooling capacity required by the user could not be exhibited.

一方、冷房運転時に、上述したような特定の室内機に流入する冷媒量が少なくなる各室内機の設置状態でない場合でも、室外機に接続される室内機の台数が多くて各室内機の定格能力の合計値が室外機の定格能力より大きい場合は、各室内機の定格能力の合計値が室外機の定格能力と同じかあるいは小さい場合と比べて、各室内機に流入する冷媒量が少なくなる。   On the other hand, even when the indoor unit is not in an installed state where the amount of refrigerant flowing into the specific indoor unit is reduced during the cooling operation, the number of indoor units connected to the outdoor unit is large and the rating of each indoor unit is high. When the total capacity is greater than the rated capacity of the outdoor unit, the amount of refrigerant flowing into each indoor unit is smaller than when the total rated capacity of each indoor unit is the same or smaller than the rated capacity of the outdoor unit. Become.

このように、室外機に接続される室内機の台数が多くて各室内機の能力の合計値が室外機の能力より大きいときに、空調負荷が大きい（例えば、当該室内機が設置される部屋の室内温度が４０℃近い高温である）室内機では、使用者が要求する冷房能力を発揮するために必要な冷媒量に対して現在流入している冷媒量では不足する場合があった。   As described above, when the number of indoor units connected to the outdoor unit is large and the total value of the capacity of each indoor unit is larger than the capacity of the outdoor unit, the air conditioning load is large (for example, the room in which the indoor unit is installed). In an indoor unit, the amount of refrigerant currently flowing in may be insufficient with respect to the amount of refrigerant necessary for exhibiting the cooling capacity required by the user.

そして、冷房運転時に上述したような理由で流入する冷媒量が不足して冷房能力が発揮できていない室内機が存在する場合は、当該室内機における冷媒過熱度が高い値（例えば、８ｄｅｇ）となっている。このとき、特許文献１に記載されているように、当該室内機で冷媒過熱度を基準値とするために対応する膨張弁の開度を大きくしても、そもそも当該室内機に流入する冷媒量が不足しているために冷媒過熱度が低下しない、つまり、当該室内機で冷媒過熱度を基準値とするために膨張弁の開度を大きくしても冷房能力を発揮できない状態は解消できないという問題があった。   When there is an indoor unit that does not exhibit cooling capacity due to a shortage of refrigerant flowing in for the reason described above during cooling operation, the refrigerant superheat degree in the indoor unit is high (for example, 8 deg). It has become. At this time, as described in Patent Document 1, even if the opening degree of the corresponding expansion valve is increased in order to set the refrigerant superheat degree as the reference value in the indoor unit, the amount of refrigerant flowing into the indoor unit in the first place The refrigerant superheat does not decrease because of the lack of refrigerant, that is, the state where the cooling capacity cannot be exhibited even if the expansion valve opening is increased in order to set the refrigerant superheat to the reference value in the indoor unit. There was a problem.

本発明は以上述べた問題点を解決するものであって、冷房能力が発揮できていない室内機に十分な量の冷媒を流入させることで、各室内機で十分な冷房能力を発揮できる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 is an air conditioner that can exhibit sufficient cooling capacity in each indoor unit by allowing a sufficient amount of refrigerant to flow into the indoor unit that does not exhibit cooling capacity. An object is to provide an apparatus.

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、室内熱交換器と室内膨張弁を有する複数台の室内機と、室内熱交換器の各々が蒸発器として機能しているときに室内熱交換器の各々から流出する冷媒の過熱度である冷媒過熱度を検出する過熱度検出手段と、複数個の室内膨張弁の開度を調整する制御手段を有する。制御手段は、過熱度検出手段が検出した各室内機の冷媒過熱度の中の最小値である最小冷媒過熱度に基づいて目標冷媒過熱度を求め、各室内機の冷媒過熱度が目標冷媒過熱度となるように各室内膨張弁の開度を調整する。そして、制御手段は、求めた目標冷媒過熱度が予め定められた上限冷媒過熱度以上であれば上限冷媒過熱度を目標冷媒過熱度とする、および、求めた目標冷媒過熱度が予め定められた下限冷媒過熱度以下であれば下限冷媒過熱度を目標冷媒過熱度とする。   In order to solve the above problems, an air conditioner of the present invention includes an outdoor unit, a plurality of indoor units having an indoor heat exchanger and an indoor expansion valve, and each of the indoor heat exchangers functioning as an evaporator. A superheat degree detecting means for detecting the degree of superheat of the refrigerant flowing out of each of the indoor heat exchangers, and a control means for adjusting the openings of the plurality of indoor expansion valves. The control means obtains the target refrigerant superheat degree based on the minimum refrigerant superheat degree that is the minimum value among the refrigerant superheat degrees of each indoor unit detected by the superheat degree detection means, and the refrigerant superheat degree of each indoor unit is determined as the target refrigerant superheat degree. The opening degree of each indoor expansion valve is adjusted so as to be the same. The control means sets the upper limit refrigerant superheat degree as the target refrigerant superheat degree if the obtained target refrigerant superheat degree is equal to or greater than the predetermined upper limit refrigerant superheat degree, and the obtained target refrigerant superheat degree is predetermined. If it is below the lower limit refrigerant superheat degree, the lower limit refrigerant superheat degree is set as the target refrigerant superheat degree.

また、本発明の空気調和装置は、室外機と、室内熱交換器と室内膨張弁を有する複数台の室内機と、室内熱交換器が蒸発器として機能しているときに室内熱交換器から流出する冷媒の過熱度を検出する過熱度検出手段と、複数個の室内膨張弁の開度を調整する制御手段を有する。制御手段は、過熱度検出手段が検出した各室内機の冷媒過熱度の中の最小値である最小冷媒過熱度に基づいて目標冷媒過熱度を求め、各室内機の冷媒過熱度が目標冷媒過熱度となるように各室内膨張弁の開度を調整する。そして、制御手段は、目標冷媒過熱度が予め定められた上限冷媒過熱度以上であれば、上限冷媒過熱度を目標冷媒過熱度とする。   Further, the air conditioner of the present invention includes an outdoor unit, a plurality of indoor units having an indoor heat exchanger and an indoor expansion valve, and an indoor heat exchanger when the indoor heat exchanger functions as an evaporator. Superheating degree detection means for detecting the degree of superheat of the refrigerant flowing out, and control means for adjusting the opening degree of the plurality of indoor expansion valves. The control means obtains the target refrigerant superheat degree based on the minimum refrigerant superheat degree that is the minimum value among the refrigerant superheat degrees of each indoor unit detected by the superheat degree detection means, and the refrigerant superheat degree of each indoor unit is determined as the target refrigerant superheat degree. The opening degree of each indoor expansion valve is adjusted so as to be the same. The control means sets the upper limit refrigerant superheat degree as the target refrigerant superheat degree if the target refrigerant superheat degree is equal to or higher than a predetermined upper limit refrigerant superheat degree.

あるいは、制御手段は、過熱度検出手段が検出した各室内機の冷媒過熱度の中の最小値である最小冷媒過熱度に基づいて求めた目標冷媒過熱度が予め定められた下限冷媒過熱度以下であれば、下限冷媒過熱度を目標冷媒過熱度とする。   Alternatively, the control means has a target refrigerant superheat degree calculated based on a minimum refrigerant superheat degree that is a minimum value among the refrigerant superheat degrees of each indoor unit detected by the superheat degree detection means is equal to or less than a predetermined lower limit refrigerant superheat degree If so, the lower limit refrigerant superheat degree is set as the target refrigerant superheat degree.

あるいは、制御手段は、過熱度検出手段が検出した各室内機の冷媒過熱度の中の最小値である最小冷媒過熱度に基づいて求めた目標冷媒過熱度が目標冷媒過熱度が予め定められた上限冷媒過熱度以上であれば、上限冷媒過熱度を目標冷媒過熱度とし、目標冷媒過熱度が予め定められた下限冷媒過熱度以下であれば、下限冷媒過熱度を目標冷媒過熱度とする。   Alternatively, the control means has a target refrigerant superheat degree determined in advance based on a target refrigerant superheat degree determined based on a minimum refrigerant superheat degree that is the minimum value among the refrigerant superheat degrees of each indoor unit detected by the superheat degree detection means. If the upper limit refrigerant superheat degree is equal to or higher than the upper limit refrigerant superheat degree, the upper limit refrigerant superheat degree is set as the target refrigerant superheat degree, and if the target refrigerant superheat degree is equal to or lower than the predetermined lower limit refrigerant superheat degree, the lower limit refrigerant superheat degree is set as the target refrigerant superheat degree.

上記のように構成した本発明の空気調和装置によれば、冷房運転時に各室内機における冷媒過熱度の最小冷媒過熱度に基づいて目標冷媒過熱度を求め、求めた目標冷媒過熱度と上限冷媒過熱度や下限冷媒過熱度と比較した結果に基づいて、目標冷媒過熱度を上限冷媒過熱度あるいは下限冷媒過熱度として、各室内機の冷媒過熱度が目標冷媒過熱となるように各室内機の膨張弁の開度を調整する。従って、全ての室内機に十分な量の冷媒を供給できるので、各室内機で十分な冷房能力を発揮できる。   According to the air conditioner of the present invention configured as described above, the target refrigerant superheat degree is obtained based on the minimum refrigerant superheat degree of the refrigerant superheat degree in each indoor unit during the cooling operation, and the obtained target refrigerant superheat degree and the upper limit refrigerant are obtained. Based on the result of comparison with the superheat degree and the lower limit refrigerant superheat degree, the target refrigerant superheat degree is set as the upper limit refrigerant superheat degree or the lower limit refrigerant superheat degree, and the refrigerant superheat degree of each indoor unit is set to the target refrigerant overheat. Adjust the opening of the expansion valve. Therefore, since a sufficient amount of refrigerant can be supplied to all the indoor units, each of the indoor units can exhibit a sufficient cooling capacity.

本発明の実施形態における、空気調和装置の説明図であり、（Ａ）は冷媒回路図、（Ｂ）は室外機制御手段および室内機制御手段のブロック図である。It is explanatory drawing of the air conditioning apparatus in embodiment of this invention, (A) is a refrigerant circuit figure, (B) is a block diagram of an outdoor unit control means and an indoor unit control means. 本発明の実施形態における、室内機および室外機の設置図である。It is an installation figure of an indoor unit and an outdoor unit in an embodiment of the present invention. 本発明の実施形態における、室外機制御手段での処理を説明するフローチャートである。It is a flowchart explaining the process in the outdoor unit control means in embodiment of this invention.

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、先に説明した、冷房運転時に特定の室内機に流入する冷媒量が不足する設置状態として、地上に設置される１台の室外機と建物の各階に設置される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, as described above, as an installation state in which the amount of refrigerant flowing into a specific indoor unit during cooling operation is insufficient, one outdoor unit installed on the ground and three units installed on each floor of the building An explanation will be given by taking as an example an air conditioner in which indoor units are connected in parallel and all the indoor units can perform cooling operation or heating operation simultaneously. 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（Ａ）および図２に示すように、本実施形態における空気調和装置１は、地上に設置される１台の室外機２と、建物６００の各階に設置され、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 (A) and FIG. 2, the air conditioner 1 in the present embodiment is installed on the floor of one outdoor unit 2 installed on the ground and a building 600, and a liquid pipe is connected to the outdoor unit 2. 8 and the gas pipe 9 are provided with three indoor units 5a to 5c connected in parallel. 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、四方弁２２と、室外熱交換器２３と、室外膨張弁２４と、液管８の一端が接続される閉鎖弁２５と、ガス管９の一端が接続される閉鎖弁２６と、アキュムレータ２８と、室外ファン２７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 is connected to a compressor 21, a four-way valve 22, an outdoor heat exchanger 23, an outdoor expansion valve 24, a closing valve 25 to which one end of the liquid pipe 8 is connected, and one end of the gas pipe 9. A closing valve 26, an accumulator 28, and an outdoor fan 27. 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の冷媒吐出側は、後述する四方弁２２のポートａと吐出管４１で接続されており、また、圧縮機２１の冷媒吸入側は、アキュムレータ２８の冷媒流出側と吸入管４２で接続されている。   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. The refrigerant discharge side of the compressor 21 is connected to a port a of a later-described four-way valve 22 and a discharge pipe 41, and the refrigerant suction side of the compressor 21 is connected to the refrigerant outflow side of the accumulator 28 through a suction pipe 42. Has been.

四方弁２２は、冷媒の流れる方向を切り換えるための弁であり、ａ、ｂ、ｃ、ｄの４つのポートを備えている。ポートａは、上述したように圧縮機２１の冷媒吐出側と吐出管４１で接続されている。ポートｂは、室外熱交換器２３の一方の冷媒出入口と冷媒配管４３で接続されている。ポートｃは、アキュムレータ２８の冷媒流入側と冷媒配管４６で接続されている。そして、ポートｄは、閉鎖弁２６と室外機ガス管４５で接続されている。   The four-way valve 22 is a valve for switching the direction in which the refrigerant flows, and includes four ports a, b, c, and d. The port a is connected to the refrigerant discharge side of the compressor 21 by the discharge pipe 41 as described above. The port b is connected to one refrigerant inlet / outlet of the outdoor heat exchanger 23 by a refrigerant pipe 43. The port c is connected to the refrigerant inflow side of the accumulator 28 by a refrigerant pipe 46. The port d is connected to the closing valve 26 by an outdoor unit gas pipe 45.

室外熱交換器２３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を熱交換させるものである。室外熱交換器２３の一方の冷媒出入口は、上述したように四方弁２２のポートｂと冷媒配管４３で接続され、他方の冷媒出入口は室外機液管４４で閉鎖弁２５と接続されている。   The outdoor heat exchanger 23 exchanges heat between the refrigerant and outside air taken into the outdoor unit 2 by rotation of an outdoor fan 27 described later. As described above, one refrigerant inlet / outlet of the outdoor heat exchanger 23 is connected to the port b of the four-way valve 22 by the refrigerant pipe 43, and the other refrigerant inlet / outlet is connected to the closing valve 25 by the outdoor unit liquid pipe 44.

室外膨張弁２４は、室外機液管４４に設けられている。室外膨張弁２４は電子膨張弁であり、その開度が調整されることで、室外熱交換器２３に流入する冷媒量、あるいは、室外熱交換器２３から流出する冷媒量を調整する。室外膨張弁２４の開度は、空気調和装置１が冷房運転を行っている場合は全開とされる。また、空気調和装置１が暖房運転を行っている場合は、後述する吐出温度センサ３３で検出した圧縮機２１の吐出温度に応じてその開度を制御することで、吐出温度が性能上限値を超えないようにしている。   The outdoor expansion valve 24 is provided in the outdoor unit liquid pipe 44. The outdoor expansion valve 24 is an electronic expansion valve, and the amount of refrigerant flowing into the outdoor heat exchanger 23 or the amount of refrigerant flowing out of the outdoor heat exchanger 23 is adjusted by adjusting the opening thereof. The opening degree of the outdoor expansion valve 24 is fully opened when the air conditioner 1 is performing a cooling operation. In addition, when the air conditioner 1 is performing a heating operation, the opening temperature is controlled according to the discharge temperature of the compressor 21 detected by a discharge temperature sensor 33 described later, so that the discharge temperature has a performance upper limit value. I do not exceed it.

室外ファン２７は樹脂材で形成されており、室外熱交換器２３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、室外熱交換器２３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 outdoor heat exchanger 23. The outdoor fan 27 is rotated by a fan motor (not shown) to take outside air from a suction port (not shown) into the outdoor unit 2, and the outdoor air heat exchanged with the refrigerant in the outdoor heat exchanger 23 is sent from the blower outlet (not shown) to the outdoor unit 2. To the outside.

アキュムレータ２８は、上述したように、冷媒流入側が四方弁２２のポートｃと冷媒配管４６で接続されるとともに、冷媒流出側が圧縮機２１の冷媒吸入側と吸入管４２で接続されている。アキュムレータ２８は、冷媒配管４６からアキュムレータ２８の内部に流入した冷媒をガス冷媒と液冷媒に分離してガス冷媒のみを圧縮機２１に吸入させる。   As described above, the accumulator 28 has the refrigerant inflow side connected to the port c of the four-way valve 22 and the refrigerant pipe 46, and the refrigerant outflow side is connected to the refrigerant intake side of the compressor 21 through the intake pipe 42. The accumulator 28 separates the refrigerant flowing into the accumulator 28 from the refrigerant pipe 46 into a gas refrigerant and a liquid refrigerant, and causes the compressor 21 to suck only the gas refrigerant.

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（Ａ）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である吐出圧力を検出する吐出圧力センサ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。冷媒配管４６におけるアキュムレータ２８の冷媒流入口近傍には、圧縮機２１に吸入される冷媒の圧力を検出する吸入圧力センサ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. 1A, the discharge pipe 41 includes a discharge pressure sensor 31 that detects a discharge pressure that is a pressure of the refrigerant discharged from the compressor 21, and a temperature of the refrigerant discharged from the compressor 21. A discharge temperature sensor 33 for detection is provided. Near the refrigerant inlet of the accumulator 28 in the refrigerant pipe 46, a suction 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. Is provided.

室外機液管４４における室外熱交換器２３と室外膨張弁２４との間には、室外熱交換器２３に流入する冷媒の温度あるいは室外熱交換器２３から流出する冷媒の温度を検出するための室外熱交温度センサ３５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 outdoor heat exchanger 23 and the outdoor expansion valve 24 in the outdoor unit liquid pipe 44, the temperature of the refrigerant flowing into the outdoor heat exchanger 23 or the temperature of the refrigerant flowing out of the outdoor heat exchanger 23 is detected. An outdoor heat exchange temperature sensor 35 is provided. 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（Ｂ）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、センサ入力部２４０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 FIG. 1B, the outdoor unit control means 200 includes a CPU 210, a storage unit 220, a communication unit 230, and a sensor input unit 240.

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との通信を行うインターフェイスである。センサ入力部２４０は、室外機２の各種センサでの検出結果を取り込んでＣＰＵ２１０に出力する。   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 that performs communication with the indoor units 5a to 5c. The sensor input unit 240 captures detection results from various sensors of the outdoor unit 2 and outputs them to the CPU 210.

ＣＰＵ２１０は、前述した室外機２の各センサでの検出結果をセンサ入力部２４０を介して取り込む。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、四方弁２２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、室外膨張弁２４の開度調整を行う。   CPU210 takes in the detection result in each sensor of outdoor unit 2 mentioned above via sensor input part 240. FIG. 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 four-way valve 22 based on the detection results and control signals taken in. Furthermore, the CPU 210 adjusts the opening degree of the outdoor expansion valve 24 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、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。そして、３台の室内機５ａ〜５ｃは全て同じ能力であり、冷房運転時の室内熱交換器５１ａ〜５１ｃの冷媒出口側における冷媒過熱度を所定値（例えば、４ｄｅｇ）以下とできれば、各室内機で充分な暖房能力を発揮できるものである。   Next, the three indoor units 5a to 5c will be described. The three indoor units 5a to 5c are 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 parts 54a to 54c to which the other end of the gas pipe 9 is connected 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. And all three indoor units 5a-5c are the same capability, and if each refrigerant | coolant superheat degree in the refrigerant | coolant exit side of the indoor heat exchangers 51a-51c at the time of air_conditionaing | cooling operation can be made into below a predetermined value (for example, 4deg), each indoor The machine can demonstrate sufficient heating capacity.

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と室内機液管７１ａで接続され、他方の冷媒出入口がガス管接続部５４ａと室内機ガス管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 indoor air taken into the indoor unit 5a from a suction port (not shown) by rotation of a refrigerant and an indoor fan 55a described later, and one refrigerant inlet / outlet is a liquid pipe connection portion. 53a is connected to the indoor unit liquid pipe 71a, and the other refrigerant inlet / outlet port is connected to the gas pipe connecting part 54a and 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.
Note that the refrigerant pipes of the liquid pipe connecting part 53a and the gas pipe connecting part 54a are connected by welding, flare nuts, 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、室内熱交換器５１ａが凝縮器として機能する場合、すなわち、室内機５ａが暖房運転を行う場合は、その開度は、室内熱交換器５１ａの冷媒出口（液管接続部５３ａ側）での冷媒過冷却度が目標冷媒過冷却度となるように調整される。ここで、目標冷媒過冷却度とは、室内機５ａで十分な暖房能力が発揮されるための冷媒過冷却度である。また、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、すなわち、室内機５ａが冷房運転を行う場合は、その開度は、室内熱交換器５１ａの冷媒出口（ガス管接続部５４ａ側）での冷媒過熱度が後述する目標冷媒過熱度となるように調整される。   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 when the indoor heat exchanger 51a functions as a condenser, that is, when the indoor unit 5a performs heating operation, the opening degree is the refrigerant outlet of the indoor heat exchanger 51a. The refrigerant subcooling degree at the (liquid pipe connecting portion 53a side) is adjusted to be the target refrigerant subcooling degree. Here, the target refrigerant subcooling degree is a refrigerant subcooling degree for exhibiting sufficient heating capacity in the indoor unit 5a. Further, when the indoor heat exchanger 51a functions as an evaporator, that is, when the indoor unit 5a performs a cooling operation, the opening of the indoor expansion valve 52a is the refrigerant outlet (gas pipe) of the indoor heat exchanger 51a. The refrigerant superheat degree at the connection portion 54a side) is adjusted to a target refrigerant superheat degree described later.

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の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 from the suction port (not shown) into the indoor unit 5a, and the indoor air exchanged with the refrigerant in the indoor heat exchanger 51a from the blower outlet (not shown). Supply indoors.

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。室内機５ａの図示しない吸込口付近には、室内機５ａの内部に流入する室内空気の温度、すなわち吸込温度を検出する吸込温度センサ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. A suction temperature sensor 63a for detecting the temperature of the indoor air flowing into the indoor unit 5a, that is, the suction temperature, is provided near the suction port (not shown) of the indoor unit 5a.

また、室内機５ａには、室内機制御手段５００ａが備えられている。室内機制御手段５００ａは、室内機５ａの図示しない電装品箱に格納された制御基板に搭載されており、図１（Ｂ）に示すように、ＣＰＵ５１０ａと、記憶部５２０ａと、通信部５３０ａと、センサ入力部５４０ａとを備えている。   The indoor unit 5a includes an indoor unit control means 500a. The indoor unit control means 500a is mounted on a control board stored in an electrical component box (not shown) of the indoor unit 5a, and as shown in FIG. And a sensor input unit 540a.

記憶部５２０ａは、ＲＯＭやＲＡＭで構成されており、室内機５ａ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、使用者による空調運転に関する設定情報等を記憶する。通信部５３０ａは、室外機２および他の室内機５ｂ、５ｃとの通信を行うインターフェイスである。センサ入力部５４０ａは、室内機５ａの各種センサでの検出結果を取り込んでＣＰＵ５１０ａに出力する。   The storage unit 520a includes a ROM and a RAM, and stores a control program for the indoor unit 5a, detection values corresponding to detection signals from various sensors, setting information regarding air conditioning operation by the user, and the like. The communication unit 530a is an interface that communicates with the outdoor unit 2 and the other indoor units 5b and 5c. The sensor input unit 540a captures detection results from various sensors of the indoor unit 5a and outputs them to the CPU 510a.

ＣＰＵ５１０ａは、前述した室内機５ａの各センサでの検出結果をセンサ入力部５４０ａを介して取り込む。また、ＣＰＵ５１０ａは、使用者が図示しないリモコンを操作して設定した運転情報やタイマー運転設定等を含んだ信号を図示しないリモコン受光部を介して取り込む。また、ＣＰＵ５１０ａは、運転開始／停止信号や運転情報（設定温度や室内温度等）を含んだ制御信号を、通信部５３０ａを介して室外機２に送信するとともに、室外機２が検出した外気温度等の情報を含む信号を通信部５３０ａを介して室外機２から受信する。ＣＰＵ５１０ａは、取り込んだ検出結果やリモコンおよび室外機２から送信された各種信号に基づいて、室内膨張弁５２ａの開度調整や、室内ファン５５ａの駆動制御を行う。
尚、以上説明した室外機制御手段２００と室内機制御手段５００ａ〜５００ｃとで、本発明の制御手段が構成される。 The CPU 510a takes in the detection result of each sensor of the indoor unit 5a described above via the sensor input unit 540a. Further, the CPU 510a takes in a signal including operation information set by operating a remote controller (not shown), a timer operation setting, and the like via a remote control light receiving unit (not shown). Further, the CPU 510a transmits a control signal including an operation start / stop signal and operation information (set temperature, indoor temperature, etc.) to the outdoor unit 2 via the communication unit 530a, and the outdoor temperature detected by the outdoor unit 2. A signal including such information is received from the outdoor unit 2 via the communication unit 530a. The CPU 510a performs the opening degree adjustment of the indoor expansion valve 52a and the drive control of the indoor fan 55a based on the detection results acquired and various signals transmitted from the remote controller and the outdoor unit 2.
The outdoor unit control unit 200 and the indoor unit control units 500a to 500c described above constitute the control unit of the present invention.

以上説明した空気調和装置１が、図２に示す建物６００に設置されている。具体的には、室外機２が地上に配置されており、室内機５ａが１階、室内機５ｂが２階、室内機５ｃが３階に、それぞれ設置されている。そして、室外機２と室内機５ａ〜５ｃとは、上述した液管８とガス管９とで相互に接続されており、これら液管８とガス管９とは、図示しない建物６００の壁面内や天井裏に埋設されている。尚、図２では、最上階（３階）に設置されている室内機５ｃと最下階（１階）に設置されている室内機５ａとの高低差をＨで表している。   The air conditioning apparatus 1 described above is installed in a building 600 shown in FIG. Specifically, the outdoor unit 2 is arranged on the ground, the indoor unit 5a is installed on the first floor, the indoor unit 5b is installed on the second floor, and the indoor unit 5c is installed on the third floor. And the outdoor unit 2 and the indoor units 5a-5c are mutually connected by the liquid pipe 8 and the gas pipe 9 which were mentioned above, and these liquid pipe 8 and the gas pipe 9 are in the wall surface of the building 600 which is not shown in figure. Or buried in the ceiling. In FIG. 2, the height difference between the indoor unit 5c installed on the top floor (third floor) and the indoor unit 5a installed on the bottom floor (first floor) is represented by H.

次に、本実施形態における空気調和装置１の空調運転時の冷媒回路１００における冷媒の流れや各部の動作について、図１（Ａ）を用いて説明する。尚、以下の説明では、室内機５ａ〜５ｃが冷房運転を行う場合について説明し、暖房運転を行う場合については詳細な説明を省略する。また、図１（Ａ）における矢印は冷房運転時の冷媒の流れを示している。   Next, the flow of the refrigerant and the operation of each part in the refrigerant circuit 100 during the air conditioning operation of the air-conditioning apparatus 1 in the present embodiment will be described with reference to FIG. In the following description, the case where the indoor units 5a to 5c perform the cooling operation will be described, and the detailed description will be omitted for the case where the indoor operation is performed. Moreover, the arrow in FIG. 1 (A) shows the flow of the refrigerant during the cooling operation.

図１（Ａ）に示すように、室内機５ａ〜５ｃが冷房運転を行う場合、室外機制御手段２００のＣＰＵ２１０は、四方弁２２を実線で示す状態、すなわち、四方弁２２のポートａとポートｂが連通するよう、また、ポートｃとポートｄが連通するよう、切り換える。これにより、冷媒回路１００が、室外熱交換器２３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暖房サイクルとなる。   As shown in FIG. 1A, when the indoor units 5a to 5c perform the cooling operation, the CPU 210 of the outdoor unit control means 200 is a state where the four-way valve 22 is indicated by a solid line, that is, the port a and the port of the four-way valve 22. Switching is performed so that b communicates and port c and port d communicate. Thereby, the refrigerant circuit 100 becomes a heating cycle in which the outdoor heat exchanger 23 functions as a condenser and the indoor heat exchangers 51a to 51c function as an evaporator.

圧縮機２１から吐出された高圧の冷媒は、吐出管４１を流れて四方弁２２に流入し、四方弁２２から冷媒配管４３を介して室外熱交換器２３に流入する。室外熱交換器２３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。室外熱交換器２３から流出した冷媒は、室外機液管４４、開度が全開とされている室外膨張弁２４、閉鎖弁２５を介して液管８に流入する。   The high-pressure refrigerant discharged from the compressor 21 flows through the discharge pipe 41 and flows into the four-way valve 22, and flows from the four-way valve 22 into the outdoor heat exchanger 23 through the refrigerant pipe 43. The refrigerant flowing into the outdoor heat exchanger 23 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 that has flowed out of the outdoor heat exchanger 23 flows into the liquid pipe 8 through the outdoor unit liquid pipe 44, the outdoor expansion valve 24 whose opening degree is fully opened, and the closing valve 25.

液管８を流れる冷媒は、液管接続部５３ａ〜５３ｃを介して室内機５ａ〜５ｃに流入する。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で減圧されて室内熱交換器５１ａ〜５１ｃに流入する。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て冷却され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。   The refrigerant flowing through the liquid pipe 8 flows into the indoor units 5a to 5c through the liquid pipe connection portions 53a to 53c. The refrigerant flowing into the indoor units 5a to 5c flows through the indoor unit liquid pipes 71a to 71c, is decompressed by the indoor expansion valves 52a to 52c, and flows into the indoor heat exchangers 51a to 51c. The refrigerant flowing into the indoor heat exchangers 51a to 51c 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. As described above, the indoor heat exchangers 51a to 51c function as evaporators, and the indoor air that is cooled by exchanging heat with the refrigerant in the indoor heat exchangers 51a to 51c is blown into the room from a blower outlet (not shown). Thus, cooling of the room where the indoor units 5a to 5c are installed is performed.

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を流れる冷媒は、閉鎖弁２６を介して室外機２に流入する。室外機２に流入した冷媒は、室外機ガス管４５、四方弁２２、冷媒配管４６、アキュムレータ２８、吸入管４２の順に流れ、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 flows into the outdoor unit 2 through the closing valve 26. The refrigerant flowing into the outdoor unit 2 flows in the order of the outdoor unit gas pipe 45, the four-way valve 22, the refrigerant pipe 46, the accumulator 28, and the suction pipe 42, and is sucked into the compressor 21 and compressed again.

尚、室内機５ａ〜５ｃが暖房運転を行う場合、ＣＰＵ２１０は、四方弁２２を破線で示す状態、すなわち、四方弁２２のポートａとポートｄが連通するよう、また、ポートｂとポートｃが連通するように切り換える。これにより、冷媒回路１００が、室外熱交換器２３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暖房サイクルとなる。   When the indoor units 5a to 5c perform the heating operation, the CPU 210 indicates the state where the four-way valve 22 is indicated by a broken line, that is, the port a and the port d of the four-way valve 22 communicate with each other. Switch to communicate. Thereby, the refrigerant circuit 100 becomes a heating cycle in which the outdoor heat exchanger 23 functions as an evaporator and the indoor heat exchangers 51a to 51c function as condensers.

次に、図１乃至図３を用いて、本実施形態の空気調和装置１において、本発明に関わる冷媒回路の動作やその作用、および、効果について説明する。尚、室内熱交換器５１ａ〜５１ｃが蒸発器として機能するときに、室内熱交換器５１ａ〜５１ｃに流入する冷媒の温度である熱交入口温度を検出する液側温度センサ６１ａ〜６１ｃと、室内熱交換器５１ａ〜５１ｃから流出する冷媒の温度である熱交出口温度を検出するガス側温度センサ６２ａ〜６２ｃと、室外機制御手段２００と、室内機制御手段５００ａ〜５００ｃが、本発明の過熱度検出手段である。   Next, with reference to FIGS. 1 to 3, the operation, action, and effect of the refrigerant circuit according to the present invention in the air-conditioning apparatus 1 of the present embodiment will be described. Note that when the indoor heat exchangers 51a to 51c function as evaporators, liquid side temperature sensors 61a to 61c for detecting the heat inlet temperature, which is the temperature of the refrigerant flowing into the indoor heat exchangers 51a to 51c, The gas-side temperature sensors 62a to 62c for detecting the heat exchange outlet temperature, which is the temperature of the refrigerant flowing out of the heat exchangers 51a to 51c, the outdoor unit control means 200, and the indoor unit control means 500a to 500c are superheated according to the present invention. It is a degree detection means.

図２を用いて前述したように、本実施形態の空気調和装置１では、室外機２が建物６００の地上に設置されるとともに室内機５ａ〜５ｃが各階に設置されている。つまり、室外機２が室内機５ａ〜５ｃより低い位置に設置されるとともに、室内機５ａと室内機５ｃの設置場所にも高低差Ｈがある設置となっている。この場合に、空気調和装置１で冷房運転を行ったときは、以下のような問題がある。   As described above with reference to FIG. 2, in the air conditioner 1 of the present embodiment, the outdoor unit 2 is installed on the ground of the building 600 and the indoor units 5a to 5c are installed on each floor. That is, the outdoor unit 2 is installed at a position lower than the indoor units 5a to 5c, and the installation location of the indoor unit 5a and the indoor unit 5c has a height difference H. In this case, when the air-conditioning apparatus 1 performs a cooling operation, there are the following problems.

冷房運転では、圧縮機２１から吐出されたガス冷媒は、吐出管４１から四方弁２２および冷媒配管４３を介して室外熱交換器２３に流入し、室外熱交換器２３で外気と熱交換を行って凝縮して液冷媒となる。このとき、室外機２が室内機５ａ〜５ｃより低い位置に設置されているために、室外熱交換器２３で凝縮し液管８に流出した液冷媒は、重力に逆らって室内機５ａ〜５ｃに向かって液管８を流れることになる。   In the cooling operation, the gas refrigerant discharged from the compressor 21 flows into the outdoor heat exchanger 23 from the discharge pipe 41 through the four-way valve 22 and the refrigerant pipe 43, and exchanges heat with the outside air in the outdoor heat exchanger 23. And condensed into a liquid refrigerant. At this time, since the outdoor unit 2 is installed at a position lower than the indoor units 5a to 5c, the liquid refrigerant condensed in the outdoor heat exchanger 23 and flowing out to the liquid pipe 8 is against the gravity against the indoor units 5a to 5c. Will flow through the liquid pipe 8.

従って、室外機２に比べて室内機５ａ〜５ｃの設置位置が高い場合は、液管８に流出した液冷媒が室内機５ａ〜５ｃに向かって流れにくくなる。そして、各室内機５ａ〜５ｃの設置位置の高低差Ｈがある場合は、３階に設置されている室内機５ｃの室内膨張弁５２ｃの上流側（室外機２側）における冷媒圧力は、他の階に設置されている室内機５ａ、５ｂの室内膨張弁５２ａ、５２ｂの上流側における冷媒圧力よりも低くなる。このため、室内機５ｃの室内膨張弁５２ｃの上流側の冷媒圧力と下流側（室内熱交換器５１ｃ側）の冷媒圧力の圧力差が、室内機５ａ、５ｂの室内膨張弁５２ａ、５２ｂの上流側の冷媒圧力と下流側の冷媒圧力の圧力差に比べて小さくなる。   Therefore, when the installation position of the indoor units 5a to 5c is higher than that of the outdoor unit 2, the liquid refrigerant flowing out of the liquid pipe 8 is less likely to flow toward the indoor units 5a to 5c. When there is a height difference H between the installation positions of the indoor units 5a to 5c, the refrigerant pressure on the upstream side (outdoor unit 2 side) of the indoor expansion valve 52c of the indoor unit 5c installed on the third floor is other than The refrigerant pressure is lower than the refrigerant pressure on the upstream side of the indoor expansion valves 52a and 52b of the indoor units 5a and 5b installed on the floor. For this reason, the pressure difference between the refrigerant pressure upstream of the indoor expansion valve 52c of the indoor unit 5c and the refrigerant pressure downstream (the indoor heat exchanger 51c side) is upstream of the indoor expansion valves 52a and 52b of the indoor units 5a and 5b. It becomes smaller than the pressure difference between the refrigerant pressure on the side and the refrigerant pressure on the downstream side.

上記のような冷媒回路１００の状態では、室内膨張弁５２ａ〜５２ｃの上流側の冷媒圧力と下流側の冷媒圧力の圧力差が小さいほど、室内膨張弁５２ａ〜５２ｃを通過する冷媒量が少なくなる。従って、３階に設置された室内機５ｃを流れる冷媒量は、他の室内機５ａ、５ｂを流れる冷媒量と比べて少なくなる。このことは、１階（一番低い位置）に設置された室内機５ａと３階（一番高い位置）に設置された室内機５ｃの高低差Ｈが大きくなる程顕著になる。つまり、高低差が大きくなる程、室外機２から液管８に流出した液冷媒が室内機５ｃに向かって流れにくくなって室内機５ｃに流入する冷媒量が室内機５ａ、５ｂと比べて少なくなる。   In the state of the refrigerant circuit 100 as described above, the smaller the pressure difference between the refrigerant pressure upstream of the indoor expansion valves 52a to 52c and the refrigerant pressure downstream, the smaller the amount of refrigerant passing through the indoor expansion valves 52a to 52c. . Therefore, the amount of refrigerant flowing through the indoor unit 5c installed on the third floor is smaller than the amount of refrigerant flowing through the other indoor units 5a and 5b. This becomes more prominent as the height difference H between the indoor unit 5a installed on the first floor (the lowest position) and the indoor unit 5c installed on the third floor (the highest position) increases. That is, as the difference in height increases, the amount of refrigerant flowing out of the outdoor unit 2 into the liquid pipe 8 is less likely to flow toward the indoor unit 5c, and the amount of refrigerant flowing into the indoor unit 5c is smaller than that of the indoor units 5a and 5b. Become.

そして、室内機５ａと室内機５ｃの高低差がある値（例えば、５０ｍ）以上となれば、室内機５ｃに流入する冷媒量が要求される冷房能力を発揮するのに必要な冷媒量に対して不足する恐れがある。このとき、室内機５ｃに流入する冷媒量を増やすために室内膨張弁５２ｃの開度を大きくしても、そもそも室外機２から室内機５ｃに向かって流れる冷媒量が不足しているため、室内機５ｃに流入する冷媒量は増加せず、冷房能力を発揮できない状態が解消できないという問題がある。   If the height difference between the indoor unit 5a and the indoor unit 5c is a certain value (for example, 50 m) or more, the amount of refrigerant flowing into the indoor unit 5c is less than the amount of refrigerant required to exhibit the required cooling capacity. There is a risk of shortage. At this time, even if the opening of the indoor expansion valve 52c is increased to increase the amount of refrigerant flowing into the indoor unit 5c, the amount of refrigerant flowing from the outdoor unit 2 toward the indoor unit 5c is insufficient in the first place. There is a problem that the amount of the refrigerant flowing into the machine 5c does not increase, and the state where the cooling ability cannot be exhibited cannot be solved.

上記のような問題を解決するために、空気調和装置１が冷房運転を行うときに、室内機５ａ〜５ｃの室内熱交換器５１ａ〜５１ｃの冷媒出口側（ガス側閉鎖弁５４ａ〜５４ｃ側）における冷媒過熱度を定期的（例えば、３０秒毎）に求め、求めた冷媒過熱度のうち最大値と最小値を抽出してこれらの平均値を求めて目標冷媒過熱度とする。そして、室内機５ａ〜５ｃの室内膨張弁５２ａ〜５２ｃの開度を、室内熱交換器５１ａ〜５１ｃの冷媒出口側における冷媒過熱度が求めた目標冷媒過熱度となるように調整する。   In order to solve the above problems, when the air conditioner 1 performs the cooling operation, the refrigerant outlet side (the gas side shutoff valves 54a to 54c side) of the indoor heat exchangers 51a to 51c of the indoor units 5a to 5c. The refrigerant superheat degree is periodically obtained (for example, every 30 seconds), the maximum value and the minimum value are extracted from the obtained refrigerant superheat degrees, and the average value of these is obtained as the target refrigerant superheat degree. And the opening degree of the indoor expansion valves 52a-52c of the indoor units 5a-5c is adjusted so that the refrigerant | coolant superheat degree in the refrigerant | coolant exit side of the indoor heat exchangers 51a-51c may become the target refrigerant | coolant superheat degree calculated | required.

前述したように、室内膨張弁５ｃを大きくしても室内機５ｃに冷媒が流れず、室内機５ｃで冷媒量が不足して冷房能力が発揮されないとき、室内機５ａ〜５ｃの各冷媒過熱度は、例えば、室内機５ａで１ｄｅｇ、室内機５ｂで２ｄｅｇ、室内機５ｃで１１ｄｅｇ、というように、各室内機の設置位置が室外機２から上方に行く程大きくなっている。これは、室内機５ｃで冷媒量が不足することで冷媒過熱度が大きな値となっているのに対し、室内機５ａ、５ｂでは冷媒量が室内機５ｃと比べて多いため冷媒過熱度が小さい値となっていることを示す、つまり、冷房運転時の冷媒回路１００において各室内機５ａ〜５ｃでの冷媒分布が偏っていることを示す。   As described above, when the indoor expansion valve 5c is enlarged, the refrigerant does not flow into the indoor unit 5c, and when the indoor unit 5c has a shortage of refrigerant and the cooling capacity is not exerted, the degree of refrigerant superheat of each of the indoor units 5a to 5c. For example, 1 deg for the indoor unit 5 a, 2 deg for the indoor unit 5 b, and 11 deg for the indoor unit 5 c, the installation position of each indoor unit increases as it goes upward from the outdoor unit 2. This is because the refrigerant superheat degree is large because the refrigerant amount is insufficient in the indoor unit 5c, whereas the refrigerant superheat degree is small in the indoor units 5a and 5b because the refrigerant amount is large compared to the indoor unit 5c. In other words, the refrigerant distribution in the indoor units 5a to 5c is biased in the refrigerant circuit 100 during the cooling operation.

冷房運転時に、各室内機５ａ〜５ｃでの冷媒分布が偏っているときに、冷媒過熱度の最大値と最小値の平均値を目標冷媒過熱度とすると、目標冷媒過熱度（上記の例の場合では、最大値：１１ｄｅｇと最小値：１ｄｅｇの平均値である６ｄｅｇ）より冷媒過熱度の小さい室内機５ａおよび５ｂでは、冷媒過熱度を目標冷媒過熱度まで上昇させるために室内膨張弁５２ａ、５２ｂの開度が絞られる。これにより、室内機５ａ、５ｂに流入する冷媒量が減少するとともに、室内膨張弁５２ａ、５２の下流側（室内熱交換器５１ａ、５１ｂ側）における冷媒圧力が低下する。   When the refrigerant distribution in each of the indoor units 5a to 5c is biased during the cooling operation, if the average value of the maximum value and the minimum value of the refrigerant superheat is the target refrigerant superheat, the target refrigerant superheat (in the above example) In the case, in the indoor units 5a and 5b having a refrigerant superheat degree smaller than the maximum value: 11 deg and the minimum value: 6 deg), the indoor expansion valve 52a is used to increase the refrigerant superheat degree to the target refrigerant superheat degree. The opening of 52b is reduced. Thereby, while the refrigerant | coolant amount which flows in into indoor unit 5a, 5b reduces, the refrigerant | coolant pressure in the downstream (indoor heat exchanger 51a, 51b side) of indoor expansion valve 52a, 52 falls.

一方、目標冷媒過熱度より冷媒過熱度の大きい室内機５ｃでは、室内膨張弁５２ａ、５２ｂの下流側の冷媒圧力が低下することによって室内膨張弁５２ｃの下流側の冷媒圧力も低下するために、室内膨張弁５２ｃの上流側と下流側の圧力差が大きくなる。従って、室内機５ｃの冷媒過熱度を目標冷媒過熱度まで低下させるために、室内膨張弁５２ｃの開度を大きくすると室内膨張弁５２を通過する冷媒量が増加する、つまり、室内機５ｃに流入する冷媒量が増えるので、室内機５ｃの冷房能力が上昇する。   On the other hand, in the indoor unit 5c in which the refrigerant superheat degree is larger than the target refrigerant superheat degree, the refrigerant pressure on the downstream side of the indoor expansion valves 52c is reduced due to the refrigerant pressure on the downstream side of the indoor expansion valves 52a and 52b being reduced. The pressure difference between the upstream side and the downstream side of the indoor expansion valve 52c increases. Accordingly, in order to reduce the refrigerant superheat degree of the indoor unit 5c to the target refrigerant superheat degree, when the opening of the indoor expansion valve 52c is increased, the amount of refrigerant passing through the indoor expansion valve 52 increases, that is, flows into the indoor unit 5c. Since the amount of refrigerant to be increased increases, the cooling capacity of the indoor unit 5c increases.

上記のように、冷媒過熱度の最大値と最小値の平均値を目標冷媒過熱度として各膨張弁５２ａ〜５２ｃの開度調整を継続していると、この開度調整を開始してから時間が経過するのにしたがって、室内機５ａと室内機５ｂに流入する冷媒量は減少し、室内機５ｃに流入する冷媒量は増加する、つまり、室内機５ａ、５ｂに流入する冷媒量と室内機５ｃに流入する冷媒量が近づくので、各室内機５ａ〜５ｃにおける冷媒過熱度も近づいて冷媒過熱度の最大値と最小値の差が小さくなる。このことから、冷媒過熱度の最大値と最小値の差（以降、冷媒過熱度差と記載）が所定値（以降、閾過熱度差と記載）未満となれば、室内機５ａ〜５ｃにおける冷媒分布の偏りが解消したと判断できる。   As described above, if the opening degree adjustment of each of the expansion valves 52a to 52c is continued with the average value of the maximum value and the minimum value of the refrigerant superheating degree as the target refrigerant superheating degree, the time after the opening degree adjustment is started As time passes, the amount of refrigerant flowing into the indoor unit 5a and the indoor unit 5b decreases and the amount of refrigerant flowing into the indoor unit 5c increases, that is, the amount of refrigerant flowing into the indoor units 5a and 5b and the indoor unit Since the amount of refrigerant flowing into 5c approaches, the refrigerant superheat degree in each of the indoor units 5a to 5c approaches, and the difference between the maximum value and the minimum value of the refrigerant superheat degree becomes small. From this, if the difference between the maximum value and the minimum value of the refrigerant superheat degree (hereinafter referred to as the refrigerant superheat degree difference) is less than the predetermined value (hereinafter referred to as the threshold superheat degree difference), the refrigerant in the indoor units 5a to 5c. It can be determined that the distribution bias has been eliminated.

ここで、上記閾過熱度差は予め試験等を行って室外機制御手段２００の記憶部２２０に記憶されているものであり、冷媒過熱度の最大値と最小値の差が閾過熱度差以上となっていれば、冷媒過熱度が最大である室内機で要求されている冷房能力が発揮できないほど、当該室内機に流入する冷媒量が不足している状態であることが判明している値である。尚、閾過熱度差は、例えば２ｄｅｇである。   Here, the difference in the threshold superheat degree is stored in the storage unit 220 of the outdoor unit control means 200 by performing a test or the like in advance, and the difference between the maximum value and the minimum value of the refrigerant superheat degree is equal to or greater than the threshold superheat degree difference. If it is, the value that is known to be in a state where the amount of refrigerant flowing into the indoor unit is insufficient so that the cooling capacity required for the indoor unit having the maximum refrigerant superheat degree cannot be exhibited. It is. The threshold superheat difference is, for example, 2 deg.

上述したように、冷媒量バランス制御を継続して実行すると、室内機５ａと室内機５ｂに流入する冷媒量は減少し、室内機５ｃに流入する冷媒量は増加するので、室内機５ａと室内機５ｂでは冷媒過熱度が大きくなり、室内機５ｃでは冷媒過熱度が小さくなる。そして、冷媒量バランス制御を開始してから時間が経過するのにしたがって各室内機の冷媒過熱度は近づいていく。   As described above, if the refrigerant amount balance control is continuously executed, the amount of refrigerant flowing into the indoor unit 5a and the indoor unit 5b decreases and the amount of refrigerant flowing into the indoor unit 5c increases. In the unit 5b, the refrigerant superheat degree becomes large, and in the indoor unit 5c, the refrigerant superheat degree becomes small. And the refrigerant | coolant superheat degree of each indoor unit approaches as time passes after starting refrigerant | coolant amount balance control.

このような状態であるときに、冷媒過熱度の最大値と最小値を用いて求めた平均冷媒過熱度は、冷媒量バランス制御を始める前の、冷媒過熱度の最大値と最小値の間の値で安定する。このとき、この安定したときの平均冷媒過熱度が、前述した各室内機５ａ〜５ｃで定格能力を発揮できる冷媒過熱度の所定値（４ｄｅｇ）より大きい値で安定する場合がある。   In such a state, the average refrigerant superheat obtained using the maximum value and the minimum value of the refrigerant superheat degree is between the maximum value and the minimum value of the refrigerant superheat degree before starting the refrigerant amount balance control. Stable at the value. At this time, the average refrigerant superheat degree when stabilized may be stabilized at a value larger than a predetermined value (4 deg) of the refrigerant superheat degree that can exhibit the rated capacity in each of the indoor units 5a to 5c described above.

上記のように、平均冷媒過熱度が大きい値で安定した状態で冷媒量バランス制御を続行すると、室内機５ａ〜５ｃにおける冷媒過熱度を大きな平均冷媒過熱度とするために膨張弁５２ａ〜５２ｃのそれぞれの開度が小さくされ、各室内機５ａ〜５ｃに流入する冷媒量が減少するので、室内機５ａ〜５ｃの各々の冷房能力が低下するという問題がある。   As described above, when the refrigerant amount balance control is continued in a state where the average refrigerant superheat degree is stable at a large value, the expansion valves 52a to 52c are set so that the refrigerant superheat degree in the indoor units 5a to 5c becomes a large average refrigerant superheat degree. Since each opening degree is made small and the refrigerant | coolant amount which flows in into each indoor unit 5a-5c reduces, there exists a problem that the air_conditioning | cooling capability of each indoor unit 5a-5c falls.

上記のような問題点を解決するために、冷房運転を行っているときに各室内機５ａ〜５ｃにおける冷媒過熱度を用いて冷媒過熱度差を求める。そして、冷媒過熱度差が閾過熱度差以上であれば、室内機５ａ〜５ｃにおける冷媒分布に偏りがあると判断し、目標冷媒過熱度を冷媒過熱度の最大値と最小値の平均値とし、室内機５ａ〜５ｃの冷媒過熱度が当該目標冷媒過熱度となるように各膨張弁５２ａ〜５２ｃの開度調整を行う。一方、冷媒過熱度差が閾過熱度差未満であれば、冷媒過熱度の最大値と最小値の平均値が大きい値で安定している恐れがあると判断し、冷媒過熱度の最小値から所定の過熱度減算値（例えば、１ｄｅｇ）を減じた値を目標冷媒過熱度として、室内機５ａ〜５ｃにおける冷媒過熱度を目標冷媒過熱度とするために膨張弁５２ａ〜５２ｃのそれぞれの開度を調整する目標冷媒過熱度制御を実行する。   In order to solve the above problems, the refrigerant superheat difference is obtained using the refrigerant superheat degree in each of the indoor units 5a to 5c during the cooling operation. If the refrigerant superheat difference is equal to or greater than the threshold superheat difference, it is determined that the refrigerant distribution in the indoor units 5a to 5c is biased, and the target refrigerant superheat is determined as an average value of the maximum value and the minimum value of the refrigerant superheat. The degree of opening of each expansion valve 52a to 52c is adjusted so that the refrigerant superheat degree of the indoor units 5a to 5c becomes the target refrigerant superheat degree. On the other hand, if the refrigerant superheat difference is less than the threshold superheat difference, it is determined that the average value of the maximum value and the minimum value of the refrigerant superheat may be stable at a large value, and the minimum value of the refrigerant superheat is determined. The opening degree of each of the expansion valves 52a to 52c is set so that the value obtained by subtracting a predetermined superheat degree subtraction value (for example, 1 deg) is the target refrigerant superheat degree and the refrigerant superheat degree in the indoor units 5a to 5c is the target refrigerant superheat degree. The target refrigerant superheat degree control for adjusting the is executed.

上記のように、冷媒過熱度の最大値と最小値の差が閾過熱度差以上あるいは未満であるかに応じて、目標冷媒過熱度の算出方法を適宜選択して行う。目標冷媒過熱度を冷媒過熱度の最大値と最小値の平均値とすることによって、室内機５ａ〜５ｃにおける冷媒分布の偏りを解消することができる。また、目標冷媒過熱度を冷媒過熱度の最小値から所定の過熱度減算値を減じた値とすることによって、室内機５ａ〜５ｃで要求される冷房能力が十分に発揮できる量の冷媒を室内機５ａ〜５ｃの各々に供給できる。従って、空気調和装置１の冷房運転時に、室内機５ａ〜５ｃで冷媒量が不足することを防止して、各室内機５ａ〜５ｃで十分な冷房能力を発揮できる。   As described above, the calculation method of the target refrigerant superheat degree is appropriately selected according to whether the difference between the maximum value and the minimum value of the refrigerant superheat degree is greater than or less than the threshold superheat degree difference. By setting the target refrigerant superheat degree to the average value of the maximum value and the minimum value of the refrigerant superheat degree, the uneven distribution of refrigerant in the indoor units 5a to 5c can be eliminated. Further, by setting the target refrigerant superheat degree to a value obtained by subtracting a predetermined superheat degree subtracted value from the minimum value of the refrigerant superheat degree, an amount of refrigerant that can sufficiently exhibit the cooling capacity required by the indoor units 5a to 5c is supplied to the room. It can supply to each of the machines 5a-5c. Therefore, during the cooling operation of the air conditioner 1, it is possible to prevent the indoor units 5a to 5c from running out of the refrigerant amount, and to exhibit a sufficient cooling capacity in each of the indoor units 5a to 5c.

ところで、上記で説明したように、冷媒過熱度の最大値と最小値の平均値を目標冷媒過熱度とする場合、あるいは、冷媒過熱度の最小値から過熱度減算値を減じて求めた値を目標冷媒過熱度とする場合に、求めた目標冷媒過熱度が、各室内機５ａ〜５ｃで要求された冷房能力が発揮できる冷媒過熱度の上限値である上限冷媒過熱度以上の値となる、あるいは、冷媒過熱度差が閾過熱度差以上となるつまりは室内機５ａ〜５ｃにおける冷媒分布に偏りが発生する恐れがある冷媒過熱度の下限値である下限冷媒過熱度以下となることがある。   By the way, as described above, when the average value of the maximum value and the minimum value of the refrigerant superheat degree is set as the target refrigerant superheat degree, or the value obtained by subtracting the superheat degree subtraction value from the minimum value of the refrigerant superheat degree is obtained. When the target refrigerant superheat degree is set, the obtained target refrigerant superheat degree becomes a value equal to or higher than the upper limit refrigerant superheat degree that is the upper limit value of the refrigerant superheat degree that can exhibit the cooling capacity requested by each of the indoor units 5a to 5c. Alternatively, the refrigerant superheat degree difference may be equal to or greater than the threshold superheat degree difference, that is, the refrigerant superheat degree may be less than the lower limit refrigerant superheat degree that is the lower limit value of the refrigerant superheat degree that may cause bias in the refrigerant distribution in the indoor units 5a to 5c. .

まず、目標冷媒過熱度が上限冷媒過熱度以上の値となる場合の問題点について、一例として目標冷媒過熱度を平均冷媒過熱度として膨張弁５２ａ〜５２ｃのそれぞれの開度を調整することを継続している場合で説明する。目標冷媒過熱度を平均冷媒過熱度として膨張弁５２ａ〜５２ｃのそれぞれの開度を調整することを継続していると、室内機５ａ〜５ｃにおける冷媒分布の偏りが解消されて、室内機５ａ、５ｂに流入する冷媒量が減少するとともに室内機５ｃに流入する冷媒量が増加する。   First, regarding the problem when the target refrigerant superheat degree becomes a value equal to or higher than the upper limit refrigerant superheat degree, as an example, the adjustment of the respective opening degrees of the expansion valves 52a to 52c is continued with the target refrigerant superheat degree as the average refrigerant superheat degree. The case will be described. When the adjustment of the respective opening degrees of the expansion valves 52a to 52c is continued with the target refrigerant superheat degree as the average refrigerant superheat degree, the bias of the refrigerant distribution in the indoor units 5a to 5c is eliminated, and the indoor unit 5a, As the amount of refrigerant flowing into 5b decreases, the amount of refrigerant flowing into indoor unit 5c increases.

しかし、室内機５ａと室内機５ｃの設置位置の高低差Ｈが非常に大きい（例えば、５０ｍ以上）場合は、目標冷媒過熱度が、各室内機５ａ〜５ｃで要求された冷房能力が発揮できる冷媒過熱度の上限値である上限冷媒過熱度（例えば、８ｄｅｇ）以上の値となる時間が長時間継続することがある。   However, when the height difference H between the installation positions of the indoor unit 5a and the indoor unit 5c is very large (for example, 50 m or more), the target refrigerant superheat degree can exhibit the cooling capacity required for each of the indoor units 5a to 5c. There may be a case where the time when the value is equal to or higher than the upper limit refrigerant superheat degree (for example, 8 deg), which is the upper limit value of the refrigerant superheat degree, continues for a long time.

目標冷媒過熱度が上限冷媒過熱度より大きい値であれば、各室内機５ａ〜５ｃにおける冷媒過熱度が大きい目標冷媒過熱度となるように、各膨張弁５２ａ〜５２ｃの開度が小さくされる。このため、全ての室内機５ａ〜５ｃに流入する冷媒量が減少する。従って、このような状態が長時間継続すれば、室内機５ａ〜５ｃにおける冷媒分布の偏りは徐々に解消されるものの、各室内機５ａ〜５ｃで冷房能力が発揮されるまでの時間がかかる、あるいは、冷房能力が発揮されない室内機５ａ〜５ｃが発生するという問題がある。   If the target refrigerant superheat degree is larger than the upper limit refrigerant superheat degree, the opening degree of each expansion valve 52a to 52c is reduced so that the refrigerant refrigerant superheat degree in each indoor unit 5a to 5c becomes a large target refrigerant superheat degree. . For this reason, the refrigerant | coolant amount which flows in into all the indoor units 5a-5c reduces. Therefore, if such a state continues for a long time, the uneven distribution of refrigerant in the indoor units 5a to 5c is gradually eliminated, but it takes time until the cooling capacity is exhibited in each of the indoor units 5a to 5c. Or there exists a problem that the indoor units 5a-5c in which the air_conditioning | cooling capability is not exhibited generate | occur | produce.

そこで、本実施形態の空気調和装置１では、求めた目標冷媒過熱度が上限冷媒過熱度以上であれば、上限冷媒過熱度を目標冷媒過熱度とし、各室内機５ａ〜５ｃにおける冷媒過熱度が目標冷媒過熱度となるように各膨張弁５２ａ〜５２ｃの開度調整を行う。これにより、全ての室内機５ａ〜５ｃに流入する冷媒量の不要な減少を生じさせることがなくなり、各室内機５ａ〜５ｃで冷房能力が発揮されるまでの時間が短縮される。   Therefore, in the air conditioner 1 of the present embodiment, if the obtained target refrigerant superheat degree is equal to or higher than the upper limit refrigerant superheat degree, the upper limit refrigerant superheat degree is set as the target refrigerant superheat degree, and the refrigerant superheat degree in each of the indoor units 5a to 5c is set. The opening adjustment of each expansion valve 52a-52c is performed so that it may become target refrigerant | coolant superheat degree. Thereby, an unnecessary decrease in the amount of refrigerant flowing into all the indoor units 5a to 5c is not caused, and the time until the cooling capacity is exhibited in each of the indoor units 5a to 5c is shortened.

次に、目標冷媒過熱度が下限冷媒過熱度以下の値となる場合の問題点について、一例として目標冷媒過熱度を冷媒過熱度の最大値と最小値の平均値として膨張弁５２ａ〜５２ｃのそれぞれの開度を調整することで、室内機５ａ〜５ｃにおける冷媒分布の偏りが解消し、各室内機５ａ〜５ｃの冷媒過熱度のうちの最小値から過熱度減算値を減じて求めた値を目標冷媒過熱度として膨張弁５２ａ〜５２ｃのそれぞれの開度を調整する場合で説明する。   Next, regarding the problem in the case where the target refrigerant superheat degree is equal to or less than the lower limit refrigerant superheat degree, as an example, the target refrigerant superheat degree is set to the average value of the maximum value and the minimum value of the refrigerant superheat degree, and each of the expansion valves 52a to 52c. By adjusting the opening degree, the bias of the refrigerant distribution in the indoor units 5a to 5c is resolved, and the value obtained by subtracting the superheat degree subtraction value from the minimum value of the refrigerant superheat degrees of the indoor units 5a to 5c is obtained. The case where the opening degree of each of the expansion valves 52a to 52c is adjusted as the target refrigerant superheat degree will be described.

各室内機５ａ〜５ｃの冷媒過熱度のうちの最小値から過熱度減算値を減じて求めた値を目標冷媒過熱度として膨張弁５２ａ〜５２ｃのそれぞれの開度を調整するときは、各室内機５ａ〜５ｃにおける冷媒過熱度を小さな目標冷媒過熱度とするために、各膨張弁５２ａ〜５２ｃの開度が大きくされる。そして、このような膨張弁５２ａ〜５２ｃの開度調整が継続して実行されると、各室内機５ａ〜５ｃにおける冷媒過熱度のうちの最小値が小さくなって、この最小値から過熱度減算値を減じて求めた目標冷媒過熱度が、冷媒過熱度差が閾過熱度差以上となるつまりは室内機５ａ〜５ｃにおける冷媒分布に偏りが発生する恐れがある下限値である下限冷媒過熱度（例えば、２ｄｅｇ）以下となることがある。   When the opening degree of each of the expansion valves 52a to 52c is adjusted by setting the value obtained by subtracting the superheat degree subtraction value from the minimum value of the refrigerant superheat degrees of the indoor units 5a to 5c as the target refrigerant superheat degree, In order to set the refrigerant superheat degree in the machines 5a to 5c to a small target refrigerant superheat degree, the opening degree of each expansion valve 52a to 52c is increased. When the opening adjustment of the expansion valves 52a to 52c is continuously executed, the minimum value of the refrigerant superheat degree in each of the indoor units 5a to 5c becomes small, and the superheat degree is subtracted from the minimum value. The target refrigerant superheat degree obtained by subtracting the value is the lower limit refrigerant superheat degree which is a lower limit value in which the refrigerant superheat degree difference is greater than or equal to the threshold superheat degree difference, that is, the refrigerant distribution in the indoor units 5a to 5c may be biased. (For example, 2 degrees) or less.

つまり、下限冷媒過熱度以下である目標冷媒過熱度を使用して各膨張弁５２ａ〜５２ｃの開度を調整すると、室内機５ａ〜５ｃの冷媒過熱度を小さい目標冷媒過熱度とするために各膨張弁５２ａ〜５２ｃの開度が大きくなっている。このため、当該制御を継続しているときに目標冷媒過熱度の変化に応じて各膨張弁５２ａ〜５２ｃの開度が少し開閉するだけで各室内機５ａ〜５ｃにおける冷媒量が大きく変化して冷媒過熱度が大きく変化するので、再び室内機５ａ〜５ｃにおける冷媒分布に偏りが発生する恐れがある。   That is, when the opening degree of each expansion valve 52a to 52c is adjusted using the target refrigerant superheat degree that is equal to or lower than the lower limit refrigerant superheat degree, each of the indoor units 5a to 5c has a small target refrigerant superheat degree. The opening degree of the expansion valves 52a to 52c is large. For this reason, when the control is continued, the amount of refrigerant in each of the indoor units 5a to 5c changes greatly only by opening and closing the opening of each of the expansion valves 52a to 52c slightly according to the change in the target refrigerant superheat degree. Since the degree of refrigerant superheat changes greatly, there is a risk that the refrigerant distribution in the indoor units 5a to 5c will again be biased.

そこで、本実施形態の空気調和装置１では、求めた目標冷媒過熱度が下限冷媒過熱度以下であれば、下限冷媒過熱度を目標冷媒過熱度し、各室内機５ａ〜５ｃにおける冷媒過熱度が目標冷媒過熱度となるように各膨張弁５２ａ〜５２ｃの開度調整を行う。これにより、各室内機５ａ〜５ｃにおける冷媒過熱度がこの目標冷媒過熱度となるように各膨張弁５２ａ〜５２ｃの開度を調整しているときに、再び室内機５ａ〜５ｃにおける冷媒分布に偏りが発生することを防止できる。   Therefore, in the air conditioner 1 of the present embodiment, if the obtained target refrigerant superheat degree is equal to or lower than the lower limit refrigerant superheat degree, the lower limit refrigerant superheat degree is set as the target refrigerant superheat degree, and the refrigerant superheat degree in each of the indoor units 5a to 5c is set. The opening adjustment of each expansion valve 52a-52c is performed so that it may become target refrigerant | coolant superheat degree. Thereby, when the opening degree of each expansion valve 52a-52c is adjusted so that the refrigerant | coolant superheat degree in each indoor unit 5a-5c may become this target refrigerant | coolant superheat degree, it is again in the refrigerant distribution in indoor unit 5a-5c. The occurrence of bias can be prevented.

次に、図３を用いて、本実施形態の空気調和装置１における冷房運転時の制御について説明する。図３は、空気調和装置１が冷房運転を行う場合の、室外機制御部２００のＣＰＵ２１０が行う制御に関する処理の流れを示すものである。図３において、ＳＴはステップを表し、これに続く数字はステップ番号を表している。尚、図３では本発明に関わる処理を中心に説明しており、これ以外の処理、例えば、使用者の指示した設定温度や風量等の運転条件に対応した冷媒回路１００の制御、といった、空気調和装置１に関わる一般的な処理については説明を省略している。また、以下の説明では、全ての室内機５ａ〜５ｃが冷房運転を行っている場合を例に挙げて説明する。   Next, control at the time of cooling operation in the air-conditioning apparatus 1 of the present embodiment will be described with reference to FIG. FIG. 3 shows a flow of processing related to control performed by the CPU 210 of the outdoor unit control unit 200 when the air-conditioning apparatus 1 performs cooling operation. In FIG. 3, ST represents a step, and the number following this represents a step number. Note that FIG. 3 mainly illustrates the processing related to the present invention, and other processing, for example, control of the refrigerant circuit 100 corresponding to the operating conditions such as the set temperature and the air volume instructed by the user. Description of general processing related to the harmony device 1 is omitted. Moreover, in the following description, the case where all the indoor units 5a to 5c are performing the cooling operation will be described as an example.

また、以下の説明では、室内機５ａ〜５ｃの液側温度センサ６１ａ〜６１ｃで検出する室内熱交換器５１ａ〜５１ｃの冷媒入口側における冷媒温度である熱交入口温度をＴｉ（単位：℃。室内機５ａ〜５ｃ毎に個別に言及する場合は、Ｔｉａ〜Ｔｉｃ）、室内機５ａ〜５ｃのガス側温度センサ６２ａ〜６２ｃで検出する室内熱交換器５１ａ〜５１ｃの冷媒出口側における冷媒温度である熱交出口温度をＴｏ（単位：℃。室内機５ａ〜５ｃ毎に個別に言及する場合は、Ｔｏａ〜Ｔｏｃ）とする。   In the following description, the heat exchange inlet temperature, which is the refrigerant temperature on the refrigerant inlet side of the indoor heat exchangers 51a to 51c detected by the liquid side temperature sensors 61a to 61c of the indoor units 5a to 5c, is Ti (unit: ° C). When individually referring to each of the indoor units 5a to 5c, Tia to Tic), the refrigerant temperature at the refrigerant outlet side of the indoor heat exchangers 51a to 51c detected by the gas side temperature sensors 62a to 62c of the indoor units 5a to 5c. A certain heat exchange outlet temperature is To (unit: ° C., when referring to each of the indoor units 5a to 5c individually, Toa to Toc).

また、熱交出口温度Ｔｏから熱交入口温度Ｔｉを減じて求める室内機５ａ〜５ｃにおける冷媒過熱度をＳＨ（単位：ｄｅｇ。室内機５ａ〜５ｃ毎に個別に言及する場合は、ＳＨａ〜ＳＨｃ）、各室内機５ａ〜５ｃの冷媒過熱度ＳＨのうちの最大値である最大冷媒過熱度をＳＨｍａｘ、各室内機５ａ〜５ｃの冷媒過熱度ＳＨのうちの最小値である最小冷媒過熱度をＳＨｍｉｎ、最大冷媒過熱度ＳＨｍａｘと最小冷媒過熱度ＳＨｍｉｎの差である冷媒過熱度差をＳＨｄ、閾過熱度差をＳＨＴｓとする。   Further, the degree of refrigerant superheating in the indoor units 5a to 5c obtained by subtracting the heat exchange inlet temperature Ti from the heat exchange outlet temperature To is SH (unit: deg. When referring to each of the indoor units 5a to 5c individually, SH to SHc. ), The maximum refrigerant superheat degree that is the maximum value among the refrigerant superheat degrees SH of the indoor units 5a to 5c is SHmax, and the minimum refrigerant superheat degree that is the minimum value among the refrigerant superheat degrees SH of the indoor units 5a to 5c is The refrigerant superheat difference, which is the difference between SHmin, the maximum refrigerant superheat degree SHmax, and the minimum refrigerant superheat degree SHmin, is denoted by SHd, and the threshold superheat degree difference is denoted by SHTs.

さらには、最大冷媒過熱度ＳＨｍａｘや最小冷媒過熱度ＳＨｍｉｎを用いて求める目標冷媒過熱度をＳＨｇ、目標冷媒過熱度ＳＨｇを求める際に最小冷媒過熱度ＳＨｍｉｎから減じる値である過熱度減算値をＳＨｒ、目標冷媒過熱度ＳＨｇの上限値である上限冷媒過熱度をＳＨｕ、目標冷媒過熱度ＳＨｇの下限値である下限冷媒過熱度をＳＨｌとする。   Further, the target refrigerant superheat degree obtained using the maximum refrigerant superheat degree SHmax and the minimum refrigerant superheat degree SHmin is set to SHg, and the superheat degree subtraction value which is a value subtracted from the minimum refrigerant superheat degree SHmin when obtaining the target refrigerant superheat degree SHg is set to SHr. The upper limit refrigerant superheat degree that is the upper limit value of the target refrigerant superheat degree SHg is SHu, and the lower limit refrigerant superheat degree that is the lower limit value of the target refrigerant superheat degree SHg is SH1.

ここで、過熱度減算値ＳＨｒは、予め試験等を行って室外機制御手段２００の記憶部２２０に記憶されているものであり、例えば１ｄｅｇである。過熱度減算値ＳＨｒは、目標冷媒過熱度ＳＨｇの変化量を最小限に抑える整数値が選択されている。過熱度減算値ＳＨｒを例えば３ｄｅｇといった大きな値とすれば、目標冷媒過熱度ＳＨｇが大きく変化しこれに起因して室内機５ａ〜５ｃにおける冷媒分布が再び偏ることを防ぐためである。   Here, the superheat degree subtraction value SHr is stored in the storage unit 220 of the outdoor unit control means 200 by performing a test or the like in advance, and is, for example, 1 deg. As the superheat degree subtraction value SHr, an integer value that minimizes the amount of change in the target refrigerant superheat degree SHg is selected. This is because if the superheat degree subtraction value SHr is set to a large value such as 3 deg, for example, the target refrigerant superheat degree SHg is largely changed, thereby preventing the refrigerant distribution in the indoor units 5a to 5c from being biased again.

また、上限冷媒過熱度ＳＨｕおよび下限冷媒過熱度ＳＨｌも、各々が予め試験等を行って室外機制御手段２００の記憶部２２０に記憶されているものであり、例えば、上限冷媒過熱度ＳＨｕが８ｄｅｇ、下限冷媒過熱度ＳＨｓが２ｄｅｇである。前述したように。上限冷媒過熱度ＳＨｕは、各室内機５ａ〜５ｃで要求された冷房能力が発揮できる冷媒過熱度ＳＨの上限値であり、下限冷媒過熱度ＳＨｌは、冷媒過熱度差ＳＨｄが閾過熱度差ＳＨＴｓ以上とならない下限値である。   Also, the upper limit refrigerant superheat degree SHu and the lower limit refrigerant superheat degree SHl are each previously tested and stored in the storage unit 220 of the outdoor unit control means 200. For example, the upper limit refrigerant superheat degree SHu is 8 deg. The lower limit refrigerant superheat degree SHs is 2 deg. As previously mentioned. The upper limit refrigerant superheat degree SHu is the upper limit value of the refrigerant superheat degree SH that can exhibit the cooling capacity required by each of the indoor units 5a to 5c, and the lower limit refrigerant superheat degree SHl is equal to the refrigerant superheat degree difference SHd and the threshold superheat degree difference SHTs. It is a lower limit value that does not become above.

まず、ＣＰＵ２１０は、使用者の運転指示が冷房運転指示であるか否かを判断する（ＳＴ１）。冷房運転指示でなければ（ＳＴ１−Ｎｏ）、ＣＰＵ２１０は、暖房運転の開始処理である暖房運転開始処理を実行する（ＳＴ１７）。ここで、暖房運転開始処理とは、ＣＰＵ２１０が四方弁２２を操作して冷媒回路１００を暖房サイクルとすることであり、空気調和装置１が停止している状態から暖房運転を開始するとき、もしくは、冷房運転から暖房運転に切り替えられる際に行われる処理である。   First, the CPU 210 determines whether or not the user's operation instruction is a cooling operation instruction (ST1). If it is not a cooling operation instruction (ST1-No), the CPU 210 executes a heating operation start process which is a heating operation start process (ST17). Here, the heating operation start process means that the CPU 210 operates the four-way valve 22 to set the refrigerant circuit 100 to the heating cycle, and when the heating operation is started from a state where the air conditioner 1 is stopped, or This is a process performed when switching from the cooling operation to the heating operation.

そして、ＣＰＵ２１０は、圧縮機２１や室外ファン２７を所定の回転数で起動するとともに、通信部２３０を介して室内機５ａ〜５ｃに対し室内ファン５５ａ〜５５ｃの駆動制御や室内膨張弁５２ａ〜５２ｃの開度調整を行うよう指示して暖房運転の制御を開始し（ＳＴ１８）、ＳＴ１４に処理を進める。   Then, the CPU 210 activates the compressor 21 and the outdoor fan 27 at a predetermined rotational speed, and controls the driving of the indoor fans 55a to 55c and the indoor expansion valves 52a to 52c with respect to the indoor units 5a to 5c via the communication unit 230. Is instructed to adjust the opening degree of the heating and starts the control of the heating operation (ST18), and proceeds to ST14.

ＳＴ１において、冷房運転指示であれば（ＳＴ１−Ｙｅｓ）、ＣＰＵ２１０は、冷房運転開始処理を実行する（ＳＴ２）。ここで、冷房運転開始処理とは、ＣＰＵ２１０が四方弁２２を操作して冷媒回路１００を図１（Ａ）に示す状態、つまり、冷媒回路１００を冷房サイクルとすることであり、空気調和装置１が停止している状態から冷房運転を開始するとき、もしくは、暖房運転から冷房運転に切り替えられる際に行われる処理である。   If it is a cooling operation instruction in ST1 (ST1-Yes), the CPU 210 executes a cooling operation start process (ST2). Here, the cooling operation start processing means that the CPU 210 operates the four-way valve 22 to bring the refrigerant circuit 100 into the state shown in FIG. 1A, that is, the refrigerant circuit 100 is in the cooling cycle. Is a process that is performed when the cooling operation is started from a state where the operation is stopped, or when the heating operation is switched to the cooling operation.

次に、ＣＰＵ２１０は、冷房運転の開始処理を行う（ＳＴ３）。冷房運転の開始処理では、ＣＰＵ２１０は、室内機５ａ〜５ｃからの要求能力に応じた回転数で圧縮機２１や室外ファン２７を起動する。また、ＣＰＵ２１０は、室外膨張弁２４の開度を全開とする。さらには、ＣＰＵ２１０は、室内機５ａ〜５ｃに対し通信部２３０を介して冷房運転を開始する旨の運転開始信号を送信する。   Next, the CPU 210 performs a cooling operation start process (ST3). In the cooling operation start process, the CPU 210 activates the compressor 21 and the outdoor fan 27 at a rotation speed corresponding to the required capacity from the indoor units 5a to 5c. Further, the CPU 210 fully opens the opening of the outdoor expansion valve 24. Further, the CPU 210 transmits an operation start signal indicating that the cooling operation is started to the indoor units 5a to 5c via the communication unit 230.

運転開始信号を通信部５３０ａ〜５３０ｃを介して受信した室内機５ａ〜５ｃの室内機制御手段５００ａ〜５００ｃのＣＰＵ５１０ａ〜５１０ｃの各々は、使用者の風量指示に応じた回転数で室内ファン５５ａ〜５５ｃを起動する。また、ＣＰＵ５１０ａ〜５１０ｃの各々は、ガス側温度センサ６２ａ〜６２ｃで検出した熱交出口温度Ｔｏａ〜Ｔｏｃから液側温度センサ６１ａ〜６１ｃで検出した熱交入口温度Ｔｉａ〜Ｔｉｃを減じて、室内熱交換器５１ａ〜５１ｃの冷媒出口側（ガス管接続部５４ａ〜５４ｃ側）での冷媒過熱度ＳＨａ〜ＳＨｃを求め、求めた冷媒過熱度ＳＨａ〜ＳＨｃが、運転開始時の目標値である初期冷媒過熱度（例えば、４ｄｅｇ）となるように、室内膨張弁５２ａ〜５２ｃの開度を調整する。   Each of the CPUs 510a to 510c of the indoor unit control means 500a to 500c of the indoor units 5a to 5c that has received the operation start signal via the communication units 530a to 530c, the indoor fan 55a to 55c is activated. Further, each of the CPUs 510a to 510c subtracts the heat exchange inlet temperatures Tia to Tic detected by the liquid side temperature sensors 61a to 61c from the heat exchange outlet temperatures Toa to Toc detected by the gas side temperature sensors 62a to 62c, thereby Refrigerant superheat degrees SHa to SHc on the refrigerant outlet side (gas pipe connection portions 54a to 54c side) of the exchangers 51a to 51c are obtained, and the obtained refrigerant superheat degrees SHa to SHc are initial refrigerant values that are target values at the start of operation. The opening degree of the indoor expansion valves 52a to 52c is adjusted so that the degree of superheat (for example, 4 deg) is obtained.

ここで、上記初期冷媒過熱度は、予め試験等を行って求めて記憶部５３０ａ〜５３０ｃに記憶されている値であり、各室内機で冷房能力が十分に発揮されることが確認できている値である。尚、ＣＰＵ５１０ａ〜５１０ｃは、冷房運転の開始から冷媒回路１００の状態が安定するまでの間（例えば、運転開始から３分間）は、上述した運転開始時の初期冷媒過熱度となるように室内膨張弁５２ａ〜５２ｃの開度を調整する。   Here, the initial refrigerant superheat degree is a value obtained by performing a test or the like in advance and stored in the storage units 530a to 530c, and it has been confirmed that the cooling capacity is sufficiently exhibited in each indoor unit. Value. Note that the CPUs 510a to 510c are inflated indoors so that the initial refrigerant superheat degree at the start of the operation described above is maintained during the period from the start of the cooling operation until the state of the refrigerant circuit 100 is stabilized (for example, 3 minutes from the start of operation). The opening degree of the valves 52a to 52c is adjusted.

次に、ＣＰＵ２１０は、各室内機５ａ〜５ｃから熱交入口温度Ｔｉ（Ｔｉａ〜Ｔｉｃ）と熱交出口温度Ｔｏ（Ｔｏａ〜Ｔｏｃ）を通信部２３０を介して取り込む（ＳＴ４）。尚、各熱交入口温度Ｔｉおよび各熱交出口温度Ｔｏは、室内機５ａ〜５ｃにおいて液側温度センサ６１ａ〜６１ｃやガス側温度センサ６２ａ〜６２ｃでの検出値をＣＰＵ５１０ａ〜５１０ｃが取り込み、通信部５３０ａ〜５３０ｃを介して室外機２に送信しているものである。また、上述した各検出値は、所定時間毎（例えば、３０秒毎）にＣＰＵ２１０およびＣＰＵ５１０ａ〜５１０ｃに取り込まれて、記憶部２１０および記憶部５２０ａ〜５２０ｃに記憶されている。   Next, CPU210 takes in heat exchanger inlet temperature Ti (Tia-Tic) and heat exchanger outlet temperature To (Toa-Toc) from each indoor unit 5a-5c via the communication part 230 (ST4). Each of the heat exchange inlet temperatures Ti and each of the heat exchange outlet temperatures To is detected by the CPUs 510a to 510c, which are detected by the liquid side temperature sensors 61a to 61c and the gas side temperature sensors 62a to 62c in the indoor units 5a to 5c. It is transmitting to the outdoor unit 2 via the units 530a to 530c. Each detection value described above is taken into the CPU 210 and the CPUs 510a to 510c every predetermined time (for example, every 30 seconds) and stored in the storage unit 210 and the storage units 520a to 520c.

次に、ＣＰＵ２１０は、ＳＴ４で取り込んだ各室内機５ａ〜５ｃの熱交出口温度Ｔｏから熱交入口温度Ｔｉを減じて、室内機５ａ〜５ｃの冷媒過熱度ＳＨを求める（ＳＴ５）。具体的には、ＣＰＵ２１０は、室内機５ａの熱交出口温度Ｔｏａから熱交入口温度Ｔｉａを減じて冷媒過熱度ＳＨａを求め、これを室内機５ａに関連付けて記憶部２２０に記憶する。ＣＰＵ２１０は、室内機５ｂと室内機５ｃについても室内機５ａと同様に冷媒過熱度ＳＨｂ、ＳＨｃをそれぞれ求め、これらを室内機５ｂあるいは室内機５ｃに関連付けて記憶部２２０に記憶する。   Next, the CPU 210 calculates the refrigerant superheat degree SH of the indoor units 5a to 5c by subtracting the heat exchange inlet temperature Ti from the heat exchange outlet temperature To of the indoor units 5a to 5c captured in ST4 (ST5). Specifically, the CPU 210 obtains the refrigerant superheat degree SHa by subtracting the heat exchange inlet temperature Tia from the heat exchange outlet temperature Toa of the indoor unit 5a, and stores this in the storage unit 220 in association with the indoor unit 5a. Similarly to the indoor unit 5a, the CPU 210 calculates the refrigerant superheat degrees SHb and SHc for the indoor unit 5b and the indoor unit 5c, and stores them in the storage unit 220 in association with the indoor unit 5b or the indoor unit 5c.

次に、ＣＰＵ２１０は、ＳＴ５で求めた室内機５ａ〜５ｃの冷媒過熱度ＳＨａ〜ＳＨｃのうちの最大値を最大冷媒過熱度ＳＨｍａｘ、最小値を最小冷媒過熱度ＳＨｍｉｎとし、最大冷媒過熱度ＳＨｍａｘから最小冷媒過熱度ＳＨｍｉｎを減じて求めた冷媒過熱度差ＳＨｄが閾過熱度差ＳＨＴｓ以上であるか否かを判断する（ＳＴ６）。   Next, the CPU 210 sets the maximum value of the refrigerant superheat degrees SHa to SHc of the indoor units 5a to 5c obtained in ST5 as the maximum refrigerant superheat degree SHmax, the minimum value as the minimum refrigerant superheat degree SHmin, and the maximum refrigerant superheat degree SHmax. It is determined whether or not the refrigerant superheat degree difference SHd obtained by subtracting the minimum refrigerant superheat degree SHmin is equal to or greater than the threshold superheat degree difference SHTs (ST6).

冷媒過熱度差ＳＨｄが閾過熱度差ＳＨＴｓ以上であれば（ＳＴ６−Ｙｅｓ）、ＣＰＵ２１０は、最大冷媒過熱度ＳＨｍａｘと最小冷媒過熱度ＳＨｍｉｎを用いて目標冷媒過熱度ＳＨｇを求める（ＳＴ７）。ここで、目標冷媒過熱度ＳＨｇは、最大冷媒過熱度ＳＨｍａｘと最小冷媒過熱度ＳＨｍｉｎの算術平均値：［最大冷媒過熱度ＳＨｍａｘ＋最小冷媒過熱度ＳＨｍｉｎ］／２、である。
ＳＴ７の処理を終えたＣＰＵ２１０は、ＳＴ９に処理を進める。 If the refrigerant superheat degree difference SHd is equal to or greater than the threshold superheat degree difference SHTs (ST6-Yes), the CPU 210 obtains the target refrigerant superheat degree SHg using the maximum refrigerant superheat degree SHmax and the minimum refrigerant superheat degree SHmin (ST7). Here, the target refrigerant superheat degree SHg is an arithmetic average value of the maximum refrigerant superheat degree SHmax and the minimum refrigerant superheat degree SHmin: [maximum refrigerant superheat degree SHmax + minimum refrigerant superheat degree SHmin] / 2.
CPU210 which finished the process of ST7 advances a process to ST9.

一方、ＳＴ６において冷媒過熱度差ＳＨｄが閾過熱度差ＳＨＴｓ以上でなければ（ＳＴ６−Ｎｏ）、ＣＰＵ２１０は、最小冷媒過熱度ＳＨｍｉｎを用いて目標冷媒過熱度ＳＨｇを求める（ＳＴ８）。ここで、目標冷媒過熱度ＳＨｇは、最小冷媒過熱度ＳＨｍｉｎから過熱度減算値ＳＨｒを減じた値である。
ＳＴ８の処理を終えたＣＰＵ２１０は、ＳＴ９に処理を進める。 On the other hand, if the refrigerant superheat difference SHd is not greater than or equal to the threshold superheat difference SHTs in ST6 (ST6-No), the CPU 210 obtains the target refrigerant superheat degree SHg using the minimum refrigerant superheat degree SHmin (ST8). Here, the target refrigerant superheat degree SHg is a value obtained by subtracting the superheat degree subtraction value SHr from the minimum refrigerant superheat degree SHmin.
CPU210 which completed the process of ST8 advances a process to ST9.

次に、ＣＰＵ２１０は、ＳＴ７もしくはＳＴ８で求めた目標冷媒過熱度ＳＨｇが上限冷媒過熱度ＳＨｕ以上であるか否かを判断する（ＳＴ９）。目標冷媒過熱度ＳＨｇが上限冷媒過熱度ＳＨｕ以上であれば（ＳＴ９−Ｙｅｓ）、ＣＰＵ２１０は、上限冷媒過熱度ＳＨｕを目標冷媒過熱度ＳＨｇとして（ＳＴ１１）、ＳＴ１３に処理を進める。   Next, CPU 210 determines whether or not the target refrigerant superheat degree SHg obtained in ST7 or ST8 is equal to or higher than the upper limit refrigerant superheat degree SHu (ST9). If the target refrigerant superheat degree SHg is equal to or higher than the upper limit refrigerant superheat degree SHu (ST9-Yes), the CPU 210 sets the upper limit refrigerant superheat degree SHu as the target refrigerant superheat degree SHg (ST11), and proceeds to ST13.

目標冷媒過熱度ＳＨｇが上限冷媒過熱度ＳＨｕ以上でなければ（ＳＴ９−Ｎｏ）、ＣＰＵ２１０は、ＳＴ７もしくはＳＴ８で求めた目標冷媒過熱度ＳＨｇが下限冷媒過熱度ＳＨｌ以下であるか否かを判断する（ＳＴ１０）。目標冷媒過熱度ＳＨｇが下限冷媒過熱度ＳＨｌ以下でなければ（ＳＴ１０−Ｎｏ）、ＣＰＵ２１０は、ＳＴ７もしくはＳＴ８で求めた目標冷媒過熱度ＳＨｇをそのまま使用することとして、ＳＴ１３に処理を進める。目標冷媒過熱度ＳＨｇが下限冷媒過熱度ＳＨｌ以下であれば（ＳＴ１０−Ｙｅｓ）、ＣＰＵ２１０は、下限冷媒過熱度ＳＨｌを目標冷媒過熱度ＳＨｇとして（ＳＴ１２）、ＳＴ１３に処理を進める。   If the target refrigerant superheat degree SHg is not equal to or higher than the upper limit refrigerant superheat degree SHu (ST9-No), the CPU 210 determines whether or not the target refrigerant superheat degree SHg obtained in ST7 or ST8 is equal to or lower than the lower limit refrigerant superheat degree SH1. (ST10). If the target refrigerant superheat degree SHg is not less than or equal to the lower limit refrigerant superheat degree SH1 (ST10-No), the CPU 210 proceeds to ST13 by using the target refrigerant superheat degree SHg obtained in ST7 or ST8 as it is. If the target refrigerant superheat degree SHg is equal to or lower than the lower limit refrigerant superheat degree SH1 (ST10-Yes), the CPU 210 sets the lower limit refrigerant superheat degree SH1 as the target refrigerant superheat degree SHg (ST12), and proceeds to ST13.

次に、ＣＰＵ２１０は、ＳＴ９もしくはＳＴ１１もしくはＳＴ１２で決定した目標冷媒過熱度ＳＨｇを、通信部２３０を介して室内機５ａ〜５ｃに送信する（ＳＴ１３）。通信部５３０ａ〜５３０ｃを介して目標冷媒過熱度ＳＨｇを受信した室内機５ａ〜５ｃのＣＰＵ５１０ａ〜５１０ｃの各々は、ガス側温度センサ６２ａ〜６２ｃで検出した熱交出口温度Ｔｏａ〜Ｔｏｃから液側温度センサ６１ａ〜６１ｃで検出した熱交入口温度Ｔｉａ〜Ｔｉｃを減じて求めた冷媒過熱度ＳＨａ〜ＳＨｃが、室外機２から受信した目標冷媒過熱度ＳＨｇとなるように、室内膨張弁５２ａ〜５２ｃの開度を調整する。   Next, the CPU 210 transmits the target refrigerant superheat degree SHg determined in ST9, ST11, or ST12 to the indoor units 5a to 5c via the communication unit 230 (ST13). Each of the CPUs 510a to 510c of the indoor units 5a to 5c that has received the target refrigerant superheat degree SHg via the communication units 530a to 530c, the liquid side temperature from the heat exchange outlet temperatures Toa to Toc detected by the gas side temperature sensors 62a to 62c. The indoor expansion valves 52a to 52c are set so that the refrigerant superheat degrees SHa to SHc obtained by subtracting the heat exchange inlet temperatures Tia to Tic detected by the sensors 61a to 61c become the target refrigerant superheat degrees SHg received from the outdoor unit 2. Adjust the opening.

次に、ＣＰＵ２１０は、使用者による運転モード切替指示があるか否かを判断する（ＳＴ１４）。ここで、運転モード切替指示とは、現在の運転（冷房運転）から別の運転（暖房運転）への切替を指示するものである。運転モード切替指示がある場合は（ＳＴ１４−Ｙｅｓ）、ＣＰＵ２１０は、ＳＴ１に処理を戻す。運転モード切替指示がない場合は（ＳＴ１４−Ｎｏ）、ＣＰＵ２１０は、使用者による運転停止指示があるか否かを判断する（ＳＴ１５）。運転停止指示とは、全ての室内機５ａ〜５ｃが運転を停止することを指示すものである。   Next, CPU 210 determines whether or not there is an operation mode switching instruction from the user (ST14). Here, the operation mode switching instruction is an instruction to switch from the current operation (cooling operation) to another operation (heating operation). When there is an operation mode switching instruction (ST14-Yes), the CPU 210 returns the process to ST1. When there is no operation mode switching instruction (ST14-No), the CPU 210 determines whether or not there is an operation stop instruction by the user (ST15). The operation stop instruction indicates that all the indoor units 5a to 5c stop the operation.

運転停止指示があれば（ＳＴ１５−Ｙｅｓ）、ＣＰＵ２１０は、運転停止処理を実行し（ＳＴ１６）、処理を終了する。運転停止処理では、ＣＰＵ２１０は、圧縮機２１や室外ファン２７を停止するとともに室外膨張弁２４を全閉とする。また、ＣＰＵ２１０は、室内機５ａ〜５ｃに対し通信部２３０を介して運転を停止する旨の運転停止信号を送信する。運転停止信号を通信部５３０ａ〜５３０ｃを介して受信した室内機５ａ〜５ｃのＣＰＵ５１０ａ〜５１０ｃは、室内ファン５５ａ〜５５ｃを停止するとともに室内膨張弁５２ａ〜５２ｃを全閉とする。   If there is an operation stop instruction (ST15-Yes), the CPU 210 executes an operation stop process (ST16) and ends the process. In the operation stop process, the CPU 210 stops the compressor 21 and the outdoor fan 27 and fully closes the outdoor expansion valve 24. Moreover, CPU210 transmits the driving | operation stop signal to the effect of stopping a driving | operation via the communication part 230 with respect to indoor unit 5a-5c. The CPUs 510a to 510c of the indoor units 5a to 5c that have received the operation stop signals via the communication units 530a to 530c stop the indoor fans 55a to 55c and fully close the indoor expansion valves 52a to 52c.

ＳＴ１５において運転停止指示がなければ（ＳＴ１５−Ｎｏ）、ＣＰＵ２１０は、現在の運転が冷房運転であるか否かを判断する（ＳＴ１９）。現在の運転が冷房運転であれば（ＳＴ１９−Ｙｅｓ）、ＣＰＵ２１０は、ＳＴ３に処理を戻す。現在の運転が冷房運転でなければ（ＳＴ１９−Ｎｏ）、つまり、現在の運転が暖房運転であれば、ＣＰＵ２１０は、ＳＴ１８に処理を戻す。   If there is no operation stop instruction in ST15 (ST15-No), CPU 210 determines whether or not the current operation is a cooling operation (ST19). If the current operation is the cooling operation (ST19-Yes), the CPU 210 returns the process to ST3. If the current operation is not the cooling operation (ST19-No), that is, if the current operation is the heating operation, the CPU 210 returns the process to ST18.

以上説明したように、本実施形態の空気調和装置１は、冷房運転時に室内機５ａ〜５ｃにおける冷媒過熱度ＳＨａ〜ＳＨｃを求め、これらのうちの最大冷媒過熱度ＳＨｍａｘと最小冷媒過熱度ＳＨｍｉｎの差である冷媒過熱度差ＳＨｄが閾過冷却度ＳＨＴｓ以上であるか否かによって、室内膨張弁５２ａ〜５２ｃの開度調整に使用する目標冷媒過熱度ＳＨｇを、最大冷媒過熱度ＳＨｍａｘと最小冷媒過熱度ＳＨｍｉｎの平均値とするか、あるいは、最小冷媒過熱度ＳＨｍｉｎから過熱度減算値ＳＨｒを減じた値とするかを判断する。   As described above, the air conditioner 1 of the present embodiment obtains the refrigerant superheat degrees SHa to SHc in the indoor units 5a to 5c during the cooling operation, and the maximum refrigerant superheat degree SHmax and the minimum refrigerant superheat degree SHmin among these are obtained. Depending on whether or not the refrigerant superheat difference SHd, which is the difference, is equal to or greater than the threshold supercool degree SHTs, the target refrigerant superheat degree SHg used for adjusting the opening degree of the indoor expansion valves 52a to 52c is set to the maximum refrigerant superheat degree SHmax and the minimum refrigerant superheat degree SHmax. It is determined whether the average value of the superheat degree SHmin is set or a value obtained by subtracting the superheat degree subtraction value SHr from the minimum refrigerant superheat degree SHmin.

そして、求めた目標冷媒過熱度ＳＨｇが上限冷媒過熱度ＳＨｕ以上であれば、この上限冷媒過熱度ＳＨｕを目標冷媒過熱度ＳＨｇとし、各室内機５ａ〜５ｃにおける冷媒過熱度ＳＨａ〜ＳＨｃが目標冷媒過熱度ＳＨｇ（＝上限冷媒過熱度ＳＨｕ）となるように、室内膨張弁５２ａ〜５２ｃの開度を調整する。これにより、目標冷媒過熱度ＳＨｇが最大冷媒過熱度ＳＨｍａｘと最小冷媒過熱度ＳＨｍｉｎの平均値であるときに、全ての室内機５ａ〜５ｃに流入する冷媒量の不要な減少を生じさせることがなくなり、各室内機５ａ〜５ｃで冷房能力が発揮されるまでの時間が短縮される。   If the obtained target refrigerant superheat degree SHg is equal to or higher than the upper limit refrigerant superheat degree SHu, the upper limit refrigerant superheat degree SHu is set as the target refrigerant superheat degree SHg, and the refrigerant superheat degrees SHa to SHc in the indoor units 5a to 5c are the target refrigerant. The opening degree of the indoor expansion valves 52a to 52c is adjusted so that the degree of superheat becomes SHg (= the upper limit refrigerant superheat degree SHu). Thereby, when the target refrigerant superheat degree SHg is an average value of the maximum refrigerant superheat degree SHmax and the minimum refrigerant superheat degree SHmin, an unnecessary decrease in the amount of refrigerant flowing into all the indoor units 5a to 5c is prevented. The time until the cooling capacity is exhibited in each of the indoor units 5a to 5c is shortened.

また、求めた目標冷媒過熱度ＳＨｇが下限冷媒過熱度ＳＨｌ以上であれば、この下限冷媒過熱度ＳＨｌを目標冷媒過熱度ＳＨｇとし、各室内機５ａ〜５ｃにおける冷媒過熱度ＳＨａ〜ＳＨｃが目標冷媒過熱度ＳＨｇ（＝下限冷媒過熱度ＳＨｌ）となるように、室内膨張弁５２ａ〜５２ｃの開度を調整する。これにより、目標冷媒過熱度ＳＨｇが最小冷媒過熱度ＳＨｍｉｎから過熱度減算値ＳＨｒを減じた値であるときに、室内膨張弁５２ａ〜５２ｃの開度の変化に起因して再び室内機５ａ〜５ｃにおける冷媒分布に偏りが発生することを防止できる。   If the obtained target refrigerant superheat degree SHg is equal to or higher than the lower limit refrigerant superheat degree SH1, the lower limit refrigerant superheat degree SHl is set as the target refrigerant superheat degree SHg, and the refrigerant superheat degrees SHa to SHc in the indoor units 5a to 5c are set as the target refrigerant. The opening degree of the indoor expansion valves 52a to 52c is adjusted so that the degree of superheat becomes SHg (= lower limit refrigerant superheat degree SH1). Accordingly, when the target refrigerant superheat degree SHg is a value obtained by subtracting the superheat degree subtraction value SHr from the minimum refrigerant superheat degree SHmin, the indoor units 5a to 5c are again caused by the change in the opening degree of the indoor expansion valves 52a to 52c. It is possible to prevent the refrigerant distribution from becoming uneven.

尚、以上説明した実施形態では、上限冷媒過熱度ＳＨｕと下限冷媒過熱度ＳＨｌを両方を用い、目標冷媒過熱度ＳＨｇをこれらの範囲内の値とする場合について説明したが、上限冷媒過熱度ＳＨｕと下限冷媒過熱度ＳＨｌのうちのいずれか一方のみを用いてもよい。具体的には、上限冷媒過熱度ＳＨｕのみを用いる場合は、目標冷媒過熱度ＳＨｇを上限冷媒過熱度ＳＨｕを越えない値とし、下限冷媒過熱度ＳＨｌのみを用いる場合は、目標冷媒過熱度ＳＨｇを下限冷媒過熱度ＳＨｌを下回らない値とすればよい。   In the embodiment described above, the case where both the upper limit refrigerant superheat degree SHu and the lower limit refrigerant superheat degree SHl are used and the target refrigerant superheat degree SHg is set to a value within these ranges has been described, but the upper limit refrigerant superheat degree SHu is described. And either one of the lower limit refrigerant superheat degree SH1 may be used. Specifically, when only the upper limit refrigerant superheat degree SHu is used, the target refrigerant superheat degree SHg is set to a value not exceeding the upper limit refrigerant superheat degree SHu, and when only the lower limit refrigerant superheat degree SHl is used, the target refrigerant superheat degree SHg is set. What is necessary is just to set it as the value which is not less than lower limit refrigerant | coolant superheat degree SHl.

１ 空気調和装置
２ 室外機
５ａ〜５ｃ 室内機
５１ａ〜５１ｃ 室内熱交換器
５２ａ〜５２ｃ 室内膨張弁
６１ａ〜６１ｃ 液側温度センサ
６２ａ〜６２ｃ ガス側温度センサ
１００ 冷媒回路
２００ 室外機制御部
２１０ ＣＰＵ
５００ａ〜５００ｃ 室内機制御部
５１０ａ〜５１０ｃ ＣＰＵ
ＳＨ 冷媒過熱度
ＳＨｄ 冷媒過熱度差
ＳＨｇ 目標冷媒過熱度
ＳＨｒ 過熱度減算値
ＳＨｕ 上限冷媒過熱度
ＳＨｌ 下限冷媒過熱度
ＳＨｍａｘ 最大冷媒過熱度
ＳＨｍｉｎ 最小冷媒過熱度
ＳＨＴｓ 閾過熱度差
Ｔｉ 熱交入口温度
Ｔｏ 熱交出口温度 DESCRIPTION OF SYMBOLS 1 Air conditioning apparatus 2 Outdoor unit 5a-5c Indoor unit 51a-51c Indoor heat exchanger 52a-52c Indoor expansion valve 61a-61c Liquid side temperature sensor 62a-62c Gas side temperature sensor 100 Refrigerant circuit 200 Outdoor unit control part 210 CPU
500a to 500c Indoor unit controller 510a to 510c CPU
SH Refrigerant Superheat SHd Refrigerant Superheat Difference SHg Target Refrigerant Superheat SHr Superheat Subtraction Value SHu Upper Refrigerant Superheat SHl Lower Refrigerant Superheat SHmax Maximum Refrigerant Superheat SHmin Minimum Refrigerant Superheat SHTs Threshold Heat Superheat Temperature To Heat exchange outlet temperature

Claims (9)

室外機と、室内熱交換器と室内膨張弁を有する複数台の室内機と、前記室内熱交換器の各々が蒸発器として機能しているときに同室内熱交換器の各々から流出する冷媒の過熱度である冷媒過熱度を検出する過熱度検出手段と、前記複数個の室内膨張弁の開度を調整する制御手段を有する空気調和装置であって、
前記制御手段は、
少なくとも、前記過熱度検出手段が検出した前記各室内機の冷媒過熱度の中の最小値である最小冷媒過熱度に基づいて目標冷媒過熱度を求め、前記各室内機の冷媒過熱度が前記目標冷媒過熱度となるように前記各室内膨張弁の開度を調整し、
前記目標冷媒過熱度が予め定められた上限冷媒過熱度以上であれば、同上限冷媒過熱度を前記目標冷媒過熱度とする、
ことを特徴とする空気調和装置。 An outdoor unit, a plurality of indoor units having an indoor heat exchanger and an indoor expansion valve, and refrigerant flowing out of each of the indoor heat exchangers when each of the indoor heat exchangers functions as an evaporator. An air conditioner having superheat degree detection means for detecting the degree of superheat of the refrigerant that is the degree of superheat, and control means for adjusting the openings of the plurality of indoor expansion valves,
The control means includes
At least a target refrigerant superheat degree is obtained based on a minimum refrigerant superheat degree that is a minimum value among the refrigerant superheat degrees of the indoor units detected by the superheat degree detection means, and the refrigerant superheat degree of each indoor unit is determined as the target Adjust the opening of each indoor expansion valve so that the degree of refrigerant superheat,
If the target refrigerant superheat degree is equal to or higher than a predetermined upper limit refrigerant superheat degree, the upper limit refrigerant superheat degree is set as the target refrigerant superheat degree.
An air conditioner characterized by that. 前記目標冷媒過熱度は、前記最小冷媒過熱度から予め定められた過熱度減算値を減じた値である、
ことを特徴とする請求項１に記載の空気調和装置。 The target refrigerant superheat degree is a value obtained by subtracting a predetermined superheat degree subtraction value from the minimum refrigerant superheat degree.
The air conditioner according to claim 1. 前記目標冷媒過熱度は、前記最小冷媒過熱度と前記各室内機の冷媒過熱度の中の最大値である最大冷媒過熱度の平均値である、
ことを特徴とする請求項１に記載の空気調和装置。 The target refrigerant superheat degree is an average value of the maximum refrigerant superheat degree that is the maximum value among the minimum refrigerant superheat degree and the refrigerant superheat degree of each indoor unit.
The air conditioner according to claim 1. 室外機と、室内熱交換器と室内膨張弁を有する複数台の室内機と、前記室内熱交換器の各々が蒸発器として機能しているときに同室内熱交換器の各々から流出する冷媒の過熱度である冷媒過熱度を検出する過熱度検出手段と、前記複数個の室内膨張弁の開度を調整する制御手段を有する空気調和装置であって、
前記制御手段は、
少なくとも、前記過熱度検出手段が検出した前記各室内機の冷媒過熱度の中の最小値である最小冷媒過熱度に基づいて目標冷媒過熱度を求め、前記各室内機の冷媒過熱度が前記目標冷媒過熱度となるように前記各室内膨張弁の開度を調整し、
前記目標冷媒過熱度が予め定められた下限冷媒過熱度以下であれば、同下限冷媒過熱度を前記目標冷媒過熱度とする、
ことを特徴とする空気調和装置。 An outdoor unit, a plurality of indoor units having an indoor heat exchanger and an indoor expansion valve, and refrigerant flowing out of each of the indoor heat exchangers when each of the indoor heat exchangers functions as an evaporator. An air conditioner having superheat degree detection means for detecting the degree of superheat of the refrigerant that is the degree of superheat, and control means for adjusting the openings of the plurality of indoor expansion valves,
The control means includes
At least a target refrigerant superheat degree is obtained based on a minimum refrigerant superheat degree that is a minimum value among the refrigerant superheat degrees of the indoor units detected by the superheat degree detection means, and the refrigerant superheat degree of each indoor unit is determined as the target Adjust the opening of each indoor expansion valve so that the degree of refrigerant superheat,
If the target refrigerant superheat is equal to or lower than a predetermined lower limit refrigerant superheat, the lower limit refrigerant superheat is set as the target refrigerant superheat.
An air conditioner characterized by that. 前記目標冷媒過熱度は、前記最小冷媒過熱度から予め定められた過熱度減算値を減じた値である、
ことを特徴とする請求項４に記載の空気調和装置。 The target refrigerant superheat degree is a value obtained by subtracting a predetermined superheat degree subtraction value from the minimum refrigerant superheat degree.
The air conditioning apparatus according to claim 4, wherein: 前記目標冷媒過熱度は、前記最小冷媒過熱度と前記各室内機の冷媒過熱度の中の最大値である最大冷媒過熱度の平均値である、
ことを特徴とする請求項４に記載の空気調和装置。 The target refrigerant superheat degree is an average value of the maximum refrigerant superheat degree that is the maximum value among the minimum refrigerant superheat degree and the refrigerant superheat degree of each indoor unit.
The air conditioning apparatus according to claim 4, wherein: 室外機と、室内熱交換器と室内膨張弁を有する複数台の室内機と、前記室内熱交換器の各々が蒸発器として機能しているときに同室内熱交換器の各々から流出する冷媒の過熱度である冷媒過熱度を検出する過熱度検出手段と、前記複数個の室内膨張弁の開度を調整する制御手段を有する空気調和装置であって、
前記制御手段は、
少なくとも、前記過熱度検出手段が検出した前記各室内機の冷媒過熱度の中の最小値である最小冷媒過熱度に基づいて目標冷媒過熱度を求め、前記各室内機の冷媒過熱度が前記目標冷媒過熱度となるように前記各室内膨張弁の開度を調整し、
前記目標冷媒過熱度が予め定められた上限冷媒過熱度以上であれば同上限冷媒過熱度を前記目標冷媒過熱度とし、前記目標冷媒過熱度が予め定められた下限冷媒過熱度以下であれば同下限冷媒過熱度を前記目標冷媒過熱度とする、
ことを特徴とする空気調和装置。 An outdoor unit, a plurality of indoor units having an indoor heat exchanger and an indoor expansion valve, and refrigerant flowing out of each of the indoor heat exchangers when each of the indoor heat exchangers functions as an evaporator. An air conditioner having superheat degree detection means for detecting the degree of superheat of the refrigerant that is the degree of superheat, and control means for adjusting the openings of the plurality of indoor expansion valves,
The control means includes
At least a target refrigerant superheat degree is obtained based on a minimum refrigerant superheat degree that is a minimum value among the refrigerant superheat degrees of the indoor units detected by the superheat degree detection means, and the refrigerant superheat degree of each indoor unit is determined as the target Adjust the opening of each indoor expansion valve so that the degree of refrigerant superheat,
If the target refrigerant superheat is equal to or higher than a predetermined upper limit refrigerant superheat, the upper limit refrigerant superheat is set as the target refrigerant superheat, and if the target refrigerant superheat is equal to or lower than a predetermined lower limit refrigerant superheat, the same. The lower limit refrigerant superheat degree is the target refrigerant superheat degree,
An air conditioner characterized by that. 前記目標冷媒過熱度は、前記最小冷媒過熱度から予め定められた過熱度減算値を減じた値である、
ことを特徴とする請求項７に記載の空気調和装置。 The target refrigerant superheat degree is a value obtained by subtracting a predetermined superheat degree subtraction value from the minimum refrigerant superheat degree.
The air conditioning apparatus according to claim 7. 前記目標冷媒過熱度は、前記最小冷媒過熱度と前記各室内機の冷媒過熱度の中の最大値である最大冷媒過熱度の平均値である、
ことを特徴とする請求項７に記載の空気調和装置。 The target refrigerant superheat degree is an average value of the maximum refrigerant superheat degree that is the maximum value among the minimum refrigerant superheat degree and the refrigerant superheat degree of each indoor unit.
The air conditioning apparatus according to claim 7.
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CN111964233B (en) * 2020-08-28 2022-03-25 珠海拓芯科技有限公司 Opening degree control method and device and air conditioner

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