JP6638426B2 - Air conditioner - Google Patents

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係わり、より詳細には、冷媒回路における室内機の運転台数変化時の急激な冷媒流量の変化による不具合を防止する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 at least one outdoor unit by a refrigerant pipe. More specifically, the present invention relates to an air conditioner in which the number of operating indoor units in a refrigerant circuit changes rapidly. The present invention relates to an air conditioner that prevents problems caused by changes.

圧縮機と四方弁と室外熱交換器と膨張弁を有する室外機と、室内熱交換器を有する室内機が液管とガス管で接続して構成される冷媒回路を有する空気調和装置では、圧縮機から吐出されて凝縮器として機能している熱交換器に流入して凝縮した冷媒は、膨張弁を介して蒸発器として機能している熱交換器に流入して蒸発し、再び圧縮機に吸入されることで冷凍サイクルを形成している。   In an air conditioner having a refrigerant circuit configured by connecting an outdoor unit having a compressor, a four-way valve, an outdoor heat exchanger, and an expansion valve, and an indoor unit having an indoor heat exchanger with a liquid pipe and a gas pipe, The refrigerant discharged from the machine and flowing into the heat exchanger functioning as a condenser and condensed flows into the heat exchanger functioning as an evaporator via an expansion valve and evaporates, and then returns to the compressor. The inhalation forms a refrigeration cycle.

上記のような空気調和装置では、膨張弁の開度を制御して冷媒の温度を適正に制御して所望の冷凍能力で運転できるようにしている。具体的には、圧縮機から吐出される冷媒の吐出温度が目標値となるように吐出温度と目標値の差に応じて膨張弁の開度制御を行う吐出温度調節ステップや、凝縮温度と凝縮器出口温度の温度差（過冷却度）が予め定められた目標値となるように膨張弁の開度制御を行う過冷却度調節ステップや、蒸発温度と蒸発器出口温度の温度差（過熱度）が予め定められた目標値となるように膨張弁の開度制御を行う過熱度調節ステップなどがある。   In the air conditioner as described above, the degree of opening of the expansion valve is controlled to appropriately control the temperature of the refrigerant so that the refrigerant can be operated at a desired refrigeration capacity. Specifically, a discharge temperature adjustment step for controlling the degree of opening of the expansion valve according to the difference between the discharge temperature and the target value so that the discharge temperature of the refrigerant discharged from the compressor becomes the target value, A supercooling degree adjusting step for controlling the opening degree of the expansion valve so that the temperature difference (supercooling degree) of the outlet temperature of the vessel becomes a predetermined target value, and a temperature difference (superheating degree ) Is a superheat degree adjustment step of controlling the opening degree of the expansion valve so that the target value becomes a predetermined target value.

上記の過冷却度調節ステップおよび過熱度調節ステップは、室内機毎に異なる空調負荷に対して適切な冷媒循環量を各室内機へ分配する目的で行われる。このとき、ユーザが１台の室内機５に対して運転開始若しくは運転停止を指示する操作を行うと、運転する室内機（サーモオン状態の室内機）容量の変化によって、各室内機に流れる冷媒循環量が急激に変化する。そのため、各室内機５が必要とする冷媒循環量と実際に流入した冷媒循環量とが大きく離れてしまい、圧縮機２１への液バックや吐出温度Ｔｄの過昇という問題が生じる場合がある。この問題の解決策として、運転台数が変化した際に予め室外膨張弁２４の開度を調整する方法がある。例えば、運転台数の変化台数に応じたパルスを各室外膨張弁２４に加減算する方法や、外気温又は室温に対応した開度となるように各膨張弁２４を制御する方法がある。また、予め、膨張弁開度の上限値と下限値を運転台数に応じて設定して、その範囲で膨張弁の開度制御を行う方法がある（例えば、特許文献１）。   The supercooling degree adjusting step and the superheating degree adjusting step are performed for the purpose of distributing an appropriate amount of circulating refrigerant to each indoor unit with respect to an air conditioning load different for each indoor unit. At this time, when the user performs an operation of instructing one indoor unit 5 to start or stop the operation, the refrigerant circulating through each indoor unit is changed due to a change in the operating indoor unit (the indoor unit in the thermo-on state). The amount changes rapidly. For this reason, the amount of circulating refrigerant required by each indoor unit 5 and the amount of circulating refrigerant that has actually flowed in are greatly separated from each other, which may cause problems such as liquid back to the compressor 21 and an excessive rise in the discharge temperature Td. As a solution to this problem, there is a method of adjusting the opening degree of the outdoor expansion valve 24 in advance when the number of operating units changes. For example, there is a method of adding or subtracting a pulse corresponding to the number of operating vehicles to or from each outdoor expansion valve 24, or a method of controlling each expansion valve 24 so that the opening degree corresponds to the outside air temperature or room temperature. In addition, there is a method in which an upper limit value and a lower limit value of the opening degree of the expansion valve are set in advance according to the number of operating units, and the opening degree of the expansion valve is controlled within the range (for example, Patent Document 1).

特開２００５−１４７５４１号公報JP 2005-147541 A

しかし、これらの方法はいずれも運転台数変化前に各膨張弁が適正開度（各室内機で必要としている冷媒循環量を適切に分配できる開度）となっていても、運転台数が変化すると再度適正開度となるまで室外膨張弁を制御する必要があり、各膨張弁の開度が安定するまでに時間を要していた。   However, in any of these methods, even if each expansion valve has an appropriate opening degree (an opening degree capable of appropriately distributing the amount of circulating refrigerant required in each indoor unit) before the number of operating units changes, the number of operating units changes. It was necessary to control the outdoor expansion valve until the opening reached the proper degree again, and it took time for the degree of opening of each expansion valve to stabilize.

本発明は以上述べた問題点を解決するものであって、運転台数が変化しても各膨張弁の開度を各室内機で必要としている冷媒循環量を適切に分配できる開度に早く安定させることができるマルチ型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 even if the number of operating units changes, the opening degree of each expansion valve is quickly and stably set to an opening degree that can appropriately distribute the refrigerant circulation amount required in each indoor unit. It is an object to provide a multi-type air conditioner that can be operated.

上記の課題を解決するために、本発明の空気調和装置は、一台の室外機に対して、室内熱交換器を有する室内機を複数台接続し、当該各室内機を個別に運転可能としたマルチタイプ空気調和機において、サーモオン状態の前記室内機の台数が変化したとき、前記室内機の運転台数変化前の前記各室内機に対応する膨張弁の開度からそれぞれの開度流量を算出し、サーモオン状態の前記室内機の台数が変化する直前の前記開度流量の合計値を維持するように前記各膨張弁を開度制御する。   In order to solve the above problems, the air conditioner of the present invention is configured such that a plurality of indoor units having an indoor heat exchanger are connected to one outdoor unit, and each of the indoor units can be individually operated. In the multi-type air conditioner, when the number of the indoor units in the thermo-on state changes, the respective opening degree flow rates are calculated from the opening degrees of the expansion valves corresponding to the respective indoor units before the number of operating indoor units changes. Then, the opening of each of the expansion valves is controlled so as to maintain the total value of the opening flow rates immediately before the number of the indoor units in the thermo-on state changes.

また、好ましくは、前記室内機の運転台数変化時に新たにサーモオン状態に移行した前記室内機に対応する前記膨張弁は、当該新たにサーモオン状態に移行した前記室内機の能力が前記マルチタイプ空気調和機全体の能力に占める比率と前記開度流量の合計値に基づいて定められる開度となるように制御される。   Preferably, the expansion valve corresponding to the indoor unit that has newly transitioned to the thermo-on state when the number of operating indoor units changes, the capacity of the indoor unit that has newly transitioned to the thermo-on state is the multi-type air conditioning. The opening is controlled so as to be determined based on the ratio of the capacity of the entire machine and the total value of the opening flow rate.

また、好ましくは、前記室内機の運転台数変化後、前記室外機に備えられる圧縮機の回転数の変化率に応じて前記各開度流量を算出し、算出した前記各開度流量となるように前記各膨張弁の開度を制御する。   Preferably, after the number of operating indoor units changes, the respective opening flow rates are calculated according to a rate of change in the number of revolutions of a compressor provided in the outdoor unit, and the calculated opening flow rates are obtained. Next, the opening degree of each expansion valve is controlled.

上記のように構成した本発明のマルチ型空気調和装置によれば、運転台数が変化しても各膨張弁の開度を各室内機で必要としている冷媒循環量を適切に分配できる開度に早く安定させることができる。   According to the multi-type air conditioner of the present invention configured as described above, even if the number of operating units changes, the opening degree of each expansion valve is set to an opening degree that can appropriately distribute the refrigerant circulation amount required by each indoor unit. It can be stabilized quickly.

本発明の実施形態である空気調和装置の説明図であり、（Ａ）が冷媒回路図、（Ｂ）が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 conditioner which is embodiment of this invention, (A) is a refrigerant circuit diagram, (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 flow chart explaining processing in an outdoor unit control means 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であって、増加時制御を説明するフローチャートである。It is a process in the outdoor unit control means in embodiment of this invention, Comprising: It is a flowchart explaining increase control. 本発明の実施形態における、室外機制御手段での処理であって、減少時制御を説明するフローチャートである。It is a process in the outdoor unit control means in embodiment of this invention, and is a flowchart explaining control at the time of reduction. （Ａ）は、増加時制御による各室外膨張弁の開度流量の変化を示す表であり、（Ｂ）は、減少時制御による各室外膨張弁の開度流量の変化を示す表である。(A) is a table showing a change in the opening flow rate of each outdoor expansion valve by the control at the time of increase, and (B) is a table showing a change of the opening flow rate of each outdoor expansion valve by the control at the time of decrease.

以下、本発明の実施の形態を、添付図面に基づいて詳細に説明する。実施形態としては、１台の室外機に３台の室内機が並列に接続され、全ての室内機で同時に冷房運転あるいは暖房運転が行えるマルチ型の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。   Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. As an embodiment, a description will be given of an example of a multi-type air conditioner in which three indoor units are connected in parallel to one outdoor unit and a cooling operation or a heating operation can be performed simultaneously in all the indoor units. It should be noted that 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）に示すように、本実施形態における空気調和装置１は、１台の室外機２と、室外機２に第１液管８ａ、第２液管８ｂ、第３液管８ｃ、第４液管８ｄ、および、ガス管９で並列に接続された４台の室内機５ａ〜５ｄとを備えている。   As shown in FIG. 1A, the air conditioner 1 according to the present embodiment includes one outdoor unit 2 and a first liquid pipe 8 a, a second liquid pipe 8 b, a third liquid pipe 8 c, A fourth liquid pipe 8d and four indoor units 5a to 5d connected in parallel by a gas pipe 9 are provided.

上記各構成要素は次のように接続されている。第１液管８ａの一端が室外機２の第１液側閉鎖弁２８ａに、他端が室内機５ａの閉鎖弁５３ａにそれぞれ接続されている。また、第２液管８ｂの一端が室外機２の第２液側閉鎖弁２８ｂに、他端が室内機５ｂの閉鎖弁５３ｂにそれぞれ接続されている。また、第３液管８ｃの一端が室外機２の第３液側閉鎖弁２８ｃに、他端が室内機５ｃの閉鎖弁５３ｃにそれぞれ接続されている。また、第４液管８ｄの一端が室外機２の第４液側閉鎖弁２８ｄに、他端が室内機５ｄの閉鎖弁５３ｄ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のガス側閉鎖弁２９に、他端が分岐して室内機５ａ〜５ｄの各閉鎖弁５４ａ〜５４ｄにそれぞれ接続されている。このように、室外機２と室内機５ａ〜５ｄとが第１液管８ａ、第２液管８ｂ、第３液管８ｃ、第４液管８ｄ、および、ガス管９で接続されて、空気調和装置１の冷媒回路１０が構成されている。   The above components are connected as follows. One end of the first liquid pipe 8a is connected to the first liquid side closing valve 28a of the outdoor unit 2, and the other end is connected to the closing valve 53a of the indoor unit 5a. Further, one end of the second liquid pipe 8b is connected to the second liquid-side closing valve 28b of the outdoor unit 2, and the other end is connected to the closing valve 53b of the indoor unit 5b. Further, one end of the third liquid pipe 8c is connected to the third liquid side closing valve 28c of the outdoor unit 2, and the other end is connected to the closing valve 53c of the indoor unit 5c. In addition, one end of the fourth liquid pipe 8d is connected to the fourth liquid side closing valve 28d of the outdoor unit 2, and the other end is connected to the closing valve 53d of the indoor unit 5d. The gas pipe 9 has one end connected to the gas-side shut-off valve 29 of the outdoor unit 2 and the other end branched and connected to each of the shut-off valves 54a to 54d of the indoor units 5a to 5d. In this way, the outdoor unit 2 and the indoor units 5a to 5d are connected by the first liquid pipe 8a, the second liquid pipe 8b, the third liquid pipe 8c, the fourth liquid pipe 8d, and the gas pipe 9, and The refrigerant circuit 10 of the harmony device 1 is configured.

まず、図１（Ａ）を用いて、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、第１室外膨張弁２４ａと、第２室外膨張弁２４ｂと、第３室外膨張弁２４ｃと、第４室外膨張弁２４ｄと、室外ファン２７と、一端に第１液管８ａが接続された第１閉鎖弁２８ａと、一端に第２液管８ｂが接続された第２閉鎖弁２８ｂと、一端に第３液管８ｃが接続された第３閉鎖弁２８ｃと、一端に第４液管８ｄが接続された第４閉鎖弁２８ｄと、一端にガス管が接続されたガス側閉鎖弁２９と、室外機制御手段２００とを備えている。そして、室外ファン２７および室外機制御手段２００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１０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 with reference to FIG. The outdoor unit 2 includes a compressor 21, a four-way valve 22, an outdoor heat exchanger 23, a first outdoor expansion valve 24a, a second outdoor expansion valve 24b, a third outdoor expansion valve 24c, and a fourth outdoor expansion. A valve 24d, an outdoor fan 27, a first closing valve 28a having one end connected to the first liquid pipe 8a, a second closing valve 28b having one end connected to the second liquid pipe 8b, and a third liquid A third closing valve 28c to which the pipe 8c is connected, a fourth closing valve 28d to which one end is connected to the fourth liquid pipe 8d, a gas-side closing valve 29 which is connected to one end of the gas pipe, and outdoor unit control means 200. These devices except the outdoor fan 27 and the outdoor unit control means 200 are mutually connected by respective refrigerant pipes described in detail below, and constitute an outdoor unit refrigerant circuit 20 which forms a part of the refrigerant circuit 10. .

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で接続されている。また、圧縮機２１の冷媒吸入側は、後述する四方弁２２のポートｃと吸入管４２で接続されている。   The compressor 21 is a variable capacity compressor that is capable of varying the 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 four-way valve 22 described later via a discharge pipe 41. The refrigerant suction side of the compressor 21 is connected to a port c of a four-way valve 22 described later via a suction pipe 42.

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、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、圧縮機２１の冷媒吸入側と吸入管４２で接続されている。そして、ポートｄは、ガス側閉鎖弁２９と室外機ガス管４４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 has four ports a, b, c, and d. The port a is connected to a refrigerant discharge side of the compressor 21 by a discharge pipe 41. The port b is connected to one refrigerant inlet / outlet of the outdoor heat exchanger 23 via a refrigerant pipe 43. The port c is connected to the refrigerant suction side of the compressor 21 via a suction pipe 42. The port d is connected to the gas-side shut-off valve 29 by the outdoor unit gas pipe 44.

室外熱交換器２３は、後述する室外ファン２７の回転により図示しない吸込口から室外機２の内部に取り込まれた外気と冷媒と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冷媒配管４３で四方弁２２のポートｂに接続され、他方の冷媒出入口には室外機液管４５の一端が接続されている。室外熱交換器２３は、冷媒回路１０が冷房サイクルとなる場合は凝縮器として機能し、冷媒回路１０が暖房サイクルとなる場合は蒸発器として機能する。   The outdoor heat exchanger 23 exchanges heat between refrigerant and outside air taken into the interior of the outdoor unit 2 from a suction port (not shown) by rotation of an outdoor fan 27 described later. One refrigerant inlet / outlet of the outdoor heat exchanger 23 is connected to the port b of the four-way valve 22 via the refrigerant pipe 43 as described above, and one end of the outdoor unit liquid pipe 45 is connected to the other refrigerant inlet / outlet. The outdoor heat exchanger 23 functions as a condenser when the refrigerant circuit 10 is in a cooling cycle, and functions as an evaporator when the refrigerant circuit 10 is in a heating cycle.

室外機液管４５の他端には、第１液分管４６ａの一端と第２液分管４６ｂの一端と第３液分管４６ｃと第４液分管４６ｄの一端が各々接続されている。また、第１液分管４６ａの他端は第１液側閉鎖弁２８ａと接続され、第２液分管４６ｂの他端は第２液側閉鎖弁２８ｂと接続され、第３液分管４６ｃの他端は第３液側閉鎖弁２８ｃと接続され、第４液分管４６ｄの他端は第４液側閉鎖弁２８ｄと接続されている。   The other end of the outdoor unit liquid pipe 45 is connected to one end of a first liquid dividing pipe 46a, one end of a second liquid dividing pipe 46b, and one end of a third liquid dividing pipe 46c and a fourth liquid dividing pipe 46d. The other end of the first liquid dividing pipe 46a is connected to the first liquid-side closing valve 28a, the other end of the second liquid dividing pipe 46b is connected to the second liquid-side closing valve 28b, and the other end of the third liquid dividing pipe 46c. Is connected to the third liquid side closing valve 28c, and the other end of the fourth liquid dividing pipe 46d is connected to the fourth liquid side closing valve 28d.

第１液分管４６ａには、第１室外膨張弁２４ａが設けられている。また、第２液分管４６ｂには、第２室外膨張弁２４ｂが設けられている。また、第３液分管４６ｃには、第３室外膨張弁２４ｃが設けられている。さらには、第４液分管４６ｄには、第４室外膨張弁２４ｄが設けられている。   The first liquid distribution pipe 46a is provided with a first outdoor expansion valve 24a. Further, a second outdoor expansion valve 24b is provided in the second liquid dividing pipe 46b. Further, a third outdoor expansion valve 24c is provided in the third liquid distribution pipe 46c. Further, a fourth outdoor expansion valve 24d is provided in the fourth liquid dividing pipe 46d.

第１室外膨張弁２４ａ、第２室外膨張弁２４ｂ、第３室外膨張弁２４ｃ、第４室外膨張弁２４ｄは、各々電子膨張弁である。第１室外膨張弁２４ａの開度を調節することで、後述する室内機５ａの室内熱交換器５１ａを流れる冷媒量を調節する。第２室外膨張弁２４ｂの開度を調節することで、後述する室内機５ｂの室内熱交換器５１ｂを流れる冷媒量を調節する。第３室外膨張弁２４ｃの開度を調節することで、後述する室内機５ｃの室内熱交換器５１ｃを流れる冷媒量を調節する。第４室外膨張弁２４ｄの開度を調節することで、後述する室内機５ｄの室内熱交換器５１ｄを流れる冷媒量を調節する。   Each of the first outdoor expansion valve 24a, the second outdoor expansion valve 24b, the third outdoor expansion valve 24c, and the fourth outdoor expansion valve 24d is an electronic expansion valve. By adjusting the opening of the first outdoor expansion valve 24a, the amount of refrigerant flowing through the indoor heat exchanger 51a of the indoor unit 5a, which will be described later, is adjusted. By adjusting the opening of the second outdoor expansion valve 24b, the amount of refrigerant flowing through the indoor heat exchanger 51b of the indoor unit 5b, which will be described later, is adjusted. By adjusting the opening degree of the third outdoor expansion valve 24c, the amount of refrigerant flowing through the indoor heat exchanger 51c of the indoor unit 5c described later is adjusted. By adjusting the opening of the fourth outdoor expansion valve 24d, the amount of refrigerant flowing through the indoor heat exchanger 51d of the indoor unit 5d described later is adjusted.

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 near the outdoor heat exchanger 23. The outdoor fan 27 is rotated by a fan motor (not shown) to take in outside air from the suction port (not shown) into the interior of the outdoor unit 2, and the outside air, which has exchanged heat with the refrigerant in the outdoor heat exchanger 23, is blown from an outlet (not shown) to the outdoor unit. 2 to the outside.

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高圧センサ３１と、圧縮機２１から吐出される冷媒の温度である吐出温度を検出する吐出温度センサ３３とが設けられている。吸入管４２には、圧縮機２１に吸入される冷媒の圧力である吸入圧力を検出する低圧センサ３２と、圧縮機２１に吸入される冷媒の温度である吸入温度を検出する吸入温度センサ３４とが設けられている。室外熱交換器２３には、室外熱交換器２３の温度を検出する室外熱交温度センサ３５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, a discharge pipe 41 has a high-pressure sensor 31 for detecting a discharge pressure, which 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 detecting a discharge temperature is provided. The suction pipe 42 includes a low pressure sensor 32 that detects a suction pressure that is a pressure of the refrigerant sucked into the compressor 21, a suction temperature sensor 34 that detects a suction temperature that is a temperature of the refrigerant sucked into the compressor 21, and Is provided. The outdoor heat exchanger 23 is provided with an outdoor heat exchange temperature sensor 35 that detects the temperature of the outdoor heat exchanger 23.

第１液分管４６ａにおける、第１室外膨張弁２４ａと第１液側閉鎖弁２８ａとの間には、この間の第１液分管４６ａを流れる冷媒の温度を検出する第１液温度センサ３８ａが設けられている。第２液分管４６ｂにおける、第２室外膨張弁２４ｂと第２液側閉鎖弁２８ｂとの間には、この間の第２液分管４６ｂを流れる冷媒の温度を検出する第２液温度センサ３８ｂが設けられている。第３室外膨張弁２４ｃと第３液側閉鎖弁２８ｃとの間には、この間の第３液分管４６ｃを流れる冷媒の温度を検出する第３液温度センサ３８ｃが設けられている。第４室外膨張弁２４ｄと第４液側閉鎖弁２８ｄとの間には、この間の第４液分管４６ｄを流れる冷媒の温度を検出する第４液温度センサ３８ｄ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内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１００が備えられている。   A first liquid temperature sensor 38a is provided between the first outdoor expansion valve 24a and the first liquid side closing valve 28a in the first liquid dividing pipe 46a to detect the temperature of the refrigerant flowing through the first liquid dividing pipe 46a therebetween. Have been. A second liquid temperature sensor 38b is provided between the second outdoor expansion valve 24b and the second liquid side closing valve 28b in the second liquid dividing pipe 46b to detect the temperature of the refrigerant flowing through the second liquid dividing pipe 46b therebetween. Have been. Between the third outdoor expansion valve 24c and the third liquid side closing valve 28c, there is provided a third liquid temperature sensor 38c for detecting the temperature of the refrigerant flowing through the third liquid dividing pipe 46c therebetween. Between the fourth outdoor expansion valve 24d and the fourth liquid side closing valve 28d, a fourth liquid temperature sensor 38d for detecting the temperature of the refrigerant flowing through the fourth liquid dividing pipe 46d therebetween is provided. An outdoor air temperature sensor 100 for detecting the temperature of the outdoor air flowing into the outdoor unit 2, that is, the outdoor 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た制御基板に搭載されており、図１（Ｂ）に示すように、ＣＰＵ２１０と、記憶部２２０と、通信部２３０とを備えている。   The outdoor unit 2 includes an outdoor unit control unit 200. The outdoor unit control means 200 is mounted on a control board stored in an electric component box (not shown) of the outdoor unit 2, and as shown in FIG. 1B, a CPU 210, a storage unit 220, and a communication unit 230. It has.

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、後述する各種テーブル等を記憶する。通信部２３０は、室内機５ａ〜５ｄとの通信を行うインターフェイスである。   The storage unit 220 includes a ROM and a RAM, and stores a control program for the outdoor unit 2, detection values corresponding to detection signals from various sensors, control states of the compressor 21 and the outdoor fan 27, various tables to be described later, and the like. Remember. The communication unit 230 is an interface that performs communication with the indoor units 5a to 5d.

ＣＰＵ２１０は、各種センサでの検出値を取り込むとともに、室内機５ａ〜５ｄから送信される運転開始／停止信号や運転情報（設定温度や室内温度等）を含んだ運転情報信号が通信部２３０を介して入力される。ＣＰＵ２１０は、これら取り込んだ各種検出値や入力された各種情報に基づいて、第１室外膨張弁２４ａ、第２室外膨張弁２４ｂ、第３室外膨張弁２４ｃおよび第４室外膨張弁２４ｄの開度制御や、圧縮機２１や室外ファン２７の駆動制御、四方弁２２の切り換え制御を行う。   The CPU 210 captures the detection values of the various sensors, and transmits an operation information signal including operation start / stop signals and operation information (set temperature, indoor temperature, etc.) transmitted from the indoor units 5a to 5d via the communication unit 230. Is entered. The CPU 210 controls the opening degrees of the first outdoor expansion valve 24a, the second outdoor expansion valve 24b, the third outdoor expansion valve 24c, and the fourth outdoor expansion valve 24d based on the various detected values and the various input information. In addition, drive control of the compressor 21 and the outdoor fan 27 and switching control of the four-way valve 22 are performed.

次に、４台の室内機５ａ〜５ｄについて説明する。４台の室内機５ａ〜５ｄは、室内熱交換器５１ａ〜５１ｄと、第１液管８ａと第２液管８ｂと第３液管８ｃと第４液管８ｄがそれぞれ接続された液側閉鎖弁５３ａ〜５３ｄおよび分岐したガス管９の他端がそれぞれ接続されたガス側閉鎖弁５４ａ〜５４ｄと、室内ファン５５ａ〜５５ｄと、室内機制御手段５００ａ〜５００ｄとを備えている。そして、室内ファン５５ａ〜５５ｄおよび室内機制御手段５００ａ〜５００ｄ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１０の一部をなす室内機冷媒回路５０ａ〜５０ｄを構成している。   Next, the four indoor units 5a to 5d will be described. The four indoor units 5a to 5d have liquid-side closures in which the indoor heat exchangers 51a to 51d, the first liquid pipe 8a, the second liquid pipe 8b, the third liquid pipe 8c, and the fourth liquid pipe 8d are connected, respectively. There are provided gas-side closing valves 54a to 54d to which valves 53a to 53d and the other end of the branched gas pipe 9 are respectively connected, indoor fans 55a to 55d, and indoor unit control means 500a to 500d. These devices except the indoor fans 55a to 55d and the indoor unit control means 500a to 500d are connected to each other by respective refrigerant pipes described in detail below, and the indoor unit refrigerant circuits 50a to 50a to form a part of the refrigerant circuit 10. 50d.

尚、室内機５ａ〜５ｄ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、５ｄについては説明を省略する。また、図１（Ａ）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、ｃおよびｄ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、５ｄの構成装置となる。   Since the configurations of the indoor units 5a to 5d are all the same, in the following description, only the configuration of the indoor unit 5a will be described, and the description of the other indoor units 5b, 5c, and 5d will be omitted. In FIG. 1 (A), the numbers assigned to the constituent units of the indoor unit 5a are changed from a to b, c, and d, respectively, to indicate that the indoor units 5b, 5c corresponding to the constituent units of the outdoor unit 5a. , 5d.

室内熱交換器５１ａは、冷媒と後述する室内ファン５５ａの回転により室内機５ａに備えられた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側閉鎖弁５３ａに室内機液管７１ａで接続され、他方の冷媒出入口がガス側閉鎖弁５４ａに室内機ガス管７２ａで接続されている。室内熱交換器５１ａは、室内機５ａが冷房運転を行う場合は蒸発器として機能し、室内機５ａが暖房運転を行う場合は凝縮器として機能する。   The indoor heat exchanger 51a exchanges heat between indoor air taken into the indoor unit 5a from a suction port (not shown) provided in the indoor unit 5a by rotation of a refrigerant and an indoor fan 55a described later. The refrigerant port is connected to the liquid side closing valve 53a by an indoor unit liquid pipe 71a, and the other refrigerant port is connected to the gas side closing valve 54a by an 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.

室内ファン５５ａは、室内熱交換器５１ａの近傍に配置される樹脂材で形成されたクロスフローファンであり、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の内部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室内機５ａに備えられた図示しない吹出口から室内へ供給する。   The indoor fan 55a is a cross-flow fan formed of a resin material disposed in the vicinity of the indoor heat exchanger 51a, and is rotated by a fan motor (not shown) so that the indoor fan 55a enters the indoor unit 5a from the suction port (not shown). The air is taken in, and the indoor air that has exchanged heat with the refrigerant in the indoor heat exchanger 51a is supplied into the room from an outlet (not shown) provided in the indoor unit 5a.

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。室内熱交換器５１ａには、室内熱交換器５１ａの温度を検出する室内熱交温度センサ６１ａが設けられている。また、室内機ガス管７２ａには第１ガス温度センサ６３ａが設けられている。さらに、室内機５ａの図示しない吸込口付近には、室内機５ａ内に流入する室内空気の温度、すなわち室内温度を検出する室内温度センサ６２ａが備えられている。   In addition to the configuration described above, the indoor unit 5a is provided with various sensors. The indoor heat exchanger 51a is provided with an indoor heat exchange temperature sensor 61a that detects the temperature of the indoor heat exchanger 51a. The indoor unit gas pipe 72a is provided with a first gas temperature sensor 63a. Further, an indoor temperature sensor 62a that detects the temperature of the indoor air flowing into the indoor unit 5a, that is, the indoor 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。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とを備えている。   The indoor unit 5a includes an indoor unit control unit 500a. The control unit 500a is mounted on a control board stored in an electrical component box (not shown) of the indoor unit 5a, and includes a CPU 510a, a storage unit 520a, and a communication unit 530a, as shown in FIG. ing.

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。   The storage unit 520a is configured by a ROM or 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 a 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.

ＣＰＵ５１０ａは、各種センサでの検出値を取り込むとともに、使用者が図示しないリモコンを操作して設定した運転条件やタイマー運転設定等を含んだ信号が図示しないリモコン受光部を介して入力される。ＣＰＵ５１０ａは、これら取り込んだ各種検出値や入力された各種情報に基づいて室内ファン５５ａの駆動制御を行う。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）を含んだ運転情報信号を、通信部５３０ａを介して室外機２に送信する。   The CPU 510a captures detection values from various sensors, and receives a signal including operating conditions and timer operation settings set by a user operating a remote controller (not shown) via a remote controller light receiving unit (not shown). The CPU 510a controls the driving of the indoor fan 55a based on these various detected values and the various input information. Further, the CPU 510a transmits an operation information signal including an operation start / stop signal and operation information (set temperature, indoor temperature, and the like) to the outdoor unit 2 via the communication unit 530a.

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１０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〜５ｄが暖房運転を行う場合について説明し、冷房運転／除霜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、暖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 10 during the air conditioning operation of the air-conditioning apparatus 1 according to the present embodiment will be described with reference to FIG. In the following description, a case where the indoor units 5a to 5d perform the heating operation will be described, and a detailed description will be omitted when performing the cooling operation / the defrosting operation. The arrows in FIG. 1A indicate the flow of the refrigerant during the heating operation.

図１（Ａ）に示すように、室内機５ａ〜５ｄが暖房運転を行う場合、つまり、冷媒回路１０が暖房サイクルとなる場合は、室外機２では、四方弁２２が実線で示す状態、すなわち、四方弁２２のポートａとポートｄとが連通するよう、また、ポートｂとポートｃとが連通するよう、切り換えられる。これにより、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〜５１ｄが凝縮器として機能する。   As shown in FIG. 1A, when the indoor units 5 a to 5 d perform a heating operation, that is, when the refrigerant circuit 10 is in a heating cycle, in the outdoor unit 2, the four-way valve 22 is in a state indicated by a solid line, that is, The switching is performed such that the port a and the port d of the four-way valve 22 communicate with each other, and the port b and the port c communicate with each other. Thus, the outdoor heat exchanger 23 functions as an evaporator, and the indoor heat exchangers 51a to 51d function as condensers.

圧縮機２１から吐出された高圧の冷媒は、吐出管４１から四方弁２２を介して室外機ガス管４４に流入し、室外機ガス管４４からガス側閉鎖弁２９を介してガス管９に流入する。ガス管９に流入した冷媒は分岐して、ガス側閉鎖弁５４ａ〜５４ｄを介して室内機５ａ〜５ｄに流入する。   The high-pressure refrigerant discharged from the compressor 21 flows into the outdoor unit gas pipe 44 from the discharge pipe 41 via the four-way valve 22, and flows into the gas pipe 9 from the outdoor unit gas pipe 44 via the gas-side closing valve 29. I do. The refrigerant flowing into the gas pipe 9 branches and flows into the indoor units 5a to 5d via the gas-side shut-off valves 54a to 54d.

室内機５ａ〜５ｄに流入した冷媒は、室内機ガス管７２ａ〜７２ｄを流れて室内熱交換器５１ａ〜５１ｄに流入する。室内熱交換器５１ａ〜５１ｄに流入した冷媒は、室内ファン５５ａ〜５５ｄの回転により図示しない吸込口から室内機５ａ〜５ｄの内部に取り込まれた室内空気と熱交換を行って凝縮する。このように、室内熱交換器５１ａ〜５１ｄが凝縮器として機能し、室内熱交換器５１ａ〜５１ｄで冷媒と熱交換を行って暖められた室内空気が図示しない吹出口から室内機５ａ〜５ｄが設置されている部屋に吹き出されることによって、各部屋の暖房が行われる。   The refrigerant flowing into the indoor units 5a to 5d flows through the indoor unit gas pipes 72a to 72d and flows into the indoor heat exchangers 51a to 51d. The refrigerant flowing into the indoor heat exchangers 51a to 51d exchanges heat with the indoor air taken into the indoor units 5a to 5d from the suction ports (not shown) by the rotation of the indoor fans 55a to 55d and condenses. As described above, the indoor heat exchangers 51a to 51d function as condensers, and the indoor air that has been heated by exchanging heat with the refrigerant in the indoor heat exchangers 51a to 51d is heated by the indoor units 5a to 5d from the outlet (not shown). Each room is heated by being blown out to the installed room.

室内熱交換器５１ａ〜５１ｄから流出した冷媒は室内機液管７１ａ〜７１ｄを流れ、液側閉鎖弁５３ａ〜５３ｄを介して第１液管８ａ、第２液管８ｂ、第３液管８ｃ、および第４液管８ｄに流入する。第１液管８ａ、第２液管８ｂ、第３液管８ｃ、および第４液管８ｄから第１液側閉鎖弁２８ａ、第２液側閉鎖弁２８ｂ、第３液側閉鎖弁２８ｃ、および第４液側閉鎖弁２８ｄを介して室外機２に流入した冷媒は、第１液分管４６ａ、第２液分管４６ｂ、第３液分管４６ｃ、および第４液分管４６ｄを流れて第１室外膨張弁２４ａ、第２室外膨張弁２４ｂ、第３室外膨張弁２４ｃ、および第４室外膨張弁２４ｄを通過して減圧された後、室外機液管４５に流入する。尚、第１室外膨張弁２４ａ、第２室外膨張弁２４ｂ、第３室外膨張弁２４ｃ、第４室外膨張弁２４ｄの開度制御については後述する。   The refrigerant flowing out of the indoor heat exchangers 51a to 51d flows through the indoor unit liquid pipes 71a to 71d, and flows through the first liquid pipe 8a, the second liquid pipe 8b, the third liquid pipe 8c via the liquid side closing valves 53a to 53d. And flows into the fourth liquid pipe 8d. From the first liquid pipe 8a, the second liquid pipe 8b, the third liquid pipe 8c, and the fourth liquid pipe 8d, a first liquid-side closing valve 28a, a second liquid-side closing valve 28b, a third liquid-side closing valve 28c, and The refrigerant flowing into the outdoor unit 2 via the fourth liquid side closing valve 28d flows through the first liquid dividing pipe 46a, the second liquid dividing pipe 46b, the third liquid dividing pipe 46c, and the fourth liquid dividing pipe 46d, and the first outdoor expansion. The pressure is reduced after passing through the valve 24a, the second outdoor expansion valve 24b, the third outdoor expansion valve 24c, and the fourth outdoor expansion valve 24d, and then flows into the outdoor unit liquid pipe 45. The opening control of the first outdoor expansion valve 24a, the second outdoor expansion valve 24b, the third outdoor expansion valve 24c, and the fourth outdoor expansion valve 24d will be described later.

室外機液管４５から室外熱交換器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蒸発する。室外熱交換器２３から流出した冷媒は、冷媒配管４３を流れて四方弁２２に流入し四方弁２２から吸入管４２へと流れ、圧縮機２１に吸入されて再び圧縮される。   The refrigerant that has flowed into the outdoor heat exchanger 23 from the outdoor unit liquid pipe 45 exchanges heat with the outside air taken into the outdoor unit 2 by the rotation of the outdoor fan 27 and evaporates. The refrigerant flowing out of the outdoor heat exchanger 23 flows through the refrigerant pipe 43, flows into the four-way valve 22, flows from the four-way valve 22 to the suction pipe 42, is drawn into the compressor 21, and is compressed again.

尚、室内機５ａ〜５ｄが冷房運転あるいは除霜運転を行う場合、つまり、冷媒回路１０が冷房サイクルとなる場合は、室外機２では、四方弁２２が破線で示す状態、すなわち、四方弁２２のポートａとポートｂとが連通するよう、また、ポートｃとポートｄとが連通するよう、切り換えられる。これにより、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〜５１ｄが蒸発器として機能する。   When the indoor units 5a to 5d perform the cooling operation or the defrosting operation, that is, when the refrigerant circuit 10 is in the cooling cycle, in the outdoor unit 2, the four-way valve 22 is in a state shown by a broken line, that is, the four-way valve 22 Are switched so that the ports a and b communicate with each other and the ports c and d communicate with each other. Thereby, the outdoor heat exchanger 23 functions as a condenser, and the indoor heat exchangers 51a to 51d function as evaporators.

次に、図１〜図５を用いて、本実施形態の空気調和装置１が暖房運転を行っているときの、第１室外膨張弁２４ａ、第２室外膨張弁２４ｂ、第３室外膨張弁２４ｃ、および第４室外膨張弁２４ｄの開度制御について詳細に説明する。   Next, with reference to FIGS. 1 to 5, the first outdoor expansion valve 24a, the second outdoor expansion valve 24b, and the third outdoor expansion valve 24c when the air-conditioning apparatus 1 of the present embodiment is performing the heating operation. And the opening degree control of the fourth outdoor expansion valve 24d will be described in detail.

尚、以下の説明では、高圧センサ３１で検出する圧縮機２１の吐出圧力をＰｄ、吐出圧力Ｐｄを用いて算出する室内熱交換器５１ａ〜５１ｄでの凝縮温度をＴｃ、室外熱交温度センサ３５で検出する室外熱交換器２３での蒸発温度をＴｅ、吐出温度センサ３３で検出する圧縮機２１の吐出温度をＴｄ、目標吐出温度をＴｄｔｇ、吐出温度Ｔｄと目標吐出温度Ｔｄｔｇとの差（Ｔｄ−Ｔｄｔｇ）である吐出温度差をΔＴｄとする。尚、目標吐出温度Ｔｄｔｇは、冷媒回路の安定時に圧縮機２１に吸入される冷媒の状態が適正となる温度であり、本実施形態では、凝縮温度Ｔｃと蒸発温度Ｔｅとを用いて算出する。   In the following description, the discharge pressure of the compressor 21 detected by the high-pressure sensor 31 is Pd, the condensation temperature in the indoor heat exchangers 51a to 51d calculated using the discharge pressure Pd is Tc, and the outdoor heat exchange temperature sensor 35 , The discharge temperature of the compressor 21 detected by the discharge temperature sensor 33 is Td, the target discharge temperature is Tdtg, and the difference between the discharge temperature Td and the target discharge temperature Tdtg (Td −Tdtg) is defined as ΔTd. Note that the target discharge temperature Tdtg is a temperature at which the state of the refrigerant sucked into the compressor 21 when the refrigerant circuit is stable is appropriate. In the present embodiment, the target discharge temperature Tdtg is calculated using the condensation temperature Tc and the evaporation temperature Te.

また、第１液温度センサ３８ａ、第２液温度センサ３８ｂ、第３液温度センサ３８ｃ、第４液温度センサ３８ｄで検出する熱交出口温度をそれぞれＴｌ１、Ｔｌ２、Ｔｌ３、Ｔｌ４とし、凝縮温度Ｔｃと熱交出口温度Ｔｌ１、Ｔｌ２、Ｔｌ３、Ｔｌ４それぞれとの温度差（Ｔｃ−Ｔｌ１、Ｔｃ−Ｔｌ２、Ｔｃ−Ｔｌ３、Ｔｃ−Ｔｌ４）をそれぞれ過冷却度ＳＣ１、ＳＣ２、ＳＣ３、ＳＣ４とする。また、過冷却度ＳＣ１、ＳＣ２、ＳＣ３、ＳＣ４のうち最も大きな値のものを過冷却度の最大値ＳＣｍａｘ、最も小さな値のものを過冷却度の最小値ＳＣｍｉｎ、最大値ＳＣｍａｘと最小値ＳＣｍｉｎの差をΔＳＣとする。   The heat exchange outlet temperatures detected by the first liquid temperature sensor 38a, the second liquid temperature sensor 38b, the third liquid temperature sensor 38c, and the fourth liquid temperature sensor 38d are Tl1, Tl2, Tl3, and Tl4, respectively, and the condensation temperature Tc The temperature differences (Tc-Tl1, Tc-Tl2, Tc-Tl3, Tc-Tl4) between the heat exchange outlet temperatures Tl1, Tl2, Tl3, and Tl4 are referred to as supercooling degrees SC1, SC2, SC3, and SC4, respectively. The largest value of the supercooling degrees SC1, SC2, SC3, and SC4 is the maximum value SCmax of the supercooling degree, and the smallest value is the minimum value SCmin of the supercooling degree, and the maximum value SCmax and the minimum value SCmin. Let the difference be ΔSC.

空気調和装置１が暖房運転を行っているとき、吐出温度Ｔｄが目標吐出温度Ｔｄｔｇ（目標値）となるように吐出温度差ΔＴｄに基づいて第１室外膨張弁２４ａ、第２室外膨張弁２４ｂ、第３室外膨張弁２４ｃ、および第４室外膨張弁２４ｄの開度調節を行う（吐出温度調節ステップ）。   When the air-conditioning apparatus 1 is performing the heating operation, the first outdoor expansion valve 24a, the second outdoor expansion valve 24b, the second outdoor expansion valve 24b based on the discharge temperature difference ΔTd such that the discharge temperature Td becomes the target discharge temperature Tdtg (target value). The opening degrees of the third outdoor expansion valve 24c and the fourth outdoor expansion valve 24d are adjusted (discharge temperature adjusting step).

また、上記の吐出温度調節ステップと並行して、暖房運転時は、過冷却度ＳＣ１、ＳＣ２、ＳＣ３、ＳＣ４の値が所定の目標値となるように第１室外膨張弁２４ａ、第２室外膨張弁２４ｂ、第３室外膨張弁２４ｃ、および第４室外膨張弁２４ｄの開度調節を個別に行う（過冷却度調節ステップ）。なお、過冷却度調節ステップは、各室内熱交換器５１ａ〜５１ｄの負荷に応じた循環量の冷媒を流すように第１室外膨張弁２４ａ、第２室外膨張弁２４ｂ、第３室外膨張弁２４ｃ、および第４室外膨張弁２４ｄの開度調節を個別に行う制御であり、冷房運転を行っているときは、過熱度ＳＨ１、ＳＨ２、ＳＨ３、ＳＨ４の値が所定の目標値となるように第１室外膨張弁２４ａ、第２室外膨張弁２４ｂ、第３室外膨張弁２４ｃ、および第４室外膨張弁２４ｄの開度調節を個別に行う（過熱度調節ステップ）。   In parallel with the above-described discharge temperature adjustment step, during the heating operation, the first outdoor expansion valve 24a and the second outdoor expansion valve 24a are set so that the values of the supercooling degrees SC1, SC2, SC3, and SC4 become the predetermined target values. The openings of the valve 24b, the third outdoor expansion valve 24c, and the fourth outdoor expansion valve 24d are individually adjusted (supercooling degree adjusting step). The subcooling degree adjusting step includes the first outdoor expansion valve 24a, the second outdoor expansion valve 24b, and the third outdoor expansion valve 24c such that a circulating amount of refrigerant corresponding to the load of each of the indoor heat exchangers 51a to 51d flows. , And the control for individually adjusting the opening degree of the fourth outdoor expansion valve 24d. When the cooling operation is being performed, the control is performed such that the values of the superheat degrees SH1, SH2, SH3, and SH4 become the predetermined target values. The opening degrees of the first outdoor expansion valve 24a, the second outdoor expansion valve 24b, the third outdoor expansion valve 24c, and the fourth outdoor expansion valve 24d are individually adjusted (superheat degree adjustment step).

上記の過冷却度調節ステップおよび過熱度調節ステップは、室内機毎に異なる空調負荷に対して適切な冷媒循環量を各室内機へ分配する目的で行われる。このとき、ユーザが１台の室内機５に対して運転開始若しくは運転停止を指示する操作を行うと、運転する室内機（サーモオン状態の室内機）容量の変化によって、各室内機に流れる冷媒循環量が急激に変化する。そのため、各室内機５が必要とする冷媒循環量と実際に流入した冷媒循環量とが大きく離れてしまい、圧縮機２１への液バックや吐出温度Ｔｄの過昇という問題が生じる場合がある。この問題の解決策として、運転台数が変化した際に予め室外膨張弁２４の開度を調整する方法がある。例えば、変化した台数に応じたパルスを各室外膨張弁２４に加減算する方法や、外気温又は室温に対応した開度となるように各膨張弁２４を制御する方法がある。しかし、これらの方法はいずれも運転台数変化前に各室外膨張弁２４が適正開度（各室内機５で必要としている冷媒循環量を適切に分配できる開度）となっていても、運転台数が変化すると再度適正開度となるまで室外膨張弁２４を制御する必要があり、各室外膨張弁２４の開度が安定するまでに時間を要していた。   The supercooling degree adjusting step and the superheating degree adjusting step are performed for the purpose of distributing an appropriate amount of circulating refrigerant to each indoor unit with respect to an air conditioning load different for each indoor unit. At this time, when the user performs an operation of instructing one indoor unit 5 to start or stop the operation, the refrigerant circulating through each indoor unit is changed due to a change in the operating indoor unit (the indoor unit in the thermo-on state). The amount changes rapidly. For this reason, the amount of circulating refrigerant required by each indoor unit 5 and the amount of circulating refrigerant that has actually flowed in are greatly separated from each other, which may cause problems such as liquid back to the compressor 21 and an excessive rise in the discharge temperature Td. As a solution to this problem, there is a method of adjusting the opening degree of the outdoor expansion valve 24 in advance when the number of operating units changes. For example, there is a method of adding or subtracting a pulse corresponding to the changed number to or from each outdoor expansion valve 24, and a method of controlling each expansion valve 24 so that the opening degree corresponds to the outside air temperature or the room temperature. However, in each of these methods, even if each outdoor expansion valve 24 has an appropriate opening degree (an opening degree capable of appropriately distributing the refrigerant circulation amount required in each indoor unit 5) before the change in the number of operating units, Is changed, it is necessary to control the outdoor expansion valve 24 again until the opening degree becomes appropriate, and it takes time for the opening degree of each outdoor expansion valve 24 to stabilize.

したがって、室内機５の運転台数が変化しても各室外膨張弁２４が適正開度に近い状態となっているようにすることが好ましい。   Therefore, it is preferable that each outdoor expansion valve 24 be in a state close to the appropriate opening even if the number of operating indoor units 5 changes.

そこで、本発明では、サーモオン状態の室内機の台数（運転台数）が変化したとき、変化前からサーモオン状態だった室内機５の各室外膨張弁２４の開度流量の比率を維持し、且つ、全ての室内機５の開度流量の合計値は運転台数の変化前と変わらないように各室外膨張弁を開度制御している。これによって、各室内機５で必要としている冷媒循環量を適切に分配できる開度に早く安定させることができる。   Therefore, in the present invention, when the number of indoor units in the thermo-on state (operating number) changes, the ratio of the opening degree flow rates of the outdoor expansion valves 24 of the indoor units 5 in the thermo-on state before the change is maintained, and The opening control of each outdoor expansion valve is performed so that the total value of the opening flow rates of all the indoor units 5 does not change from before the change in the number of operating units. This makes it possible to quickly stabilize the opening degree at which the amount of circulating refrigerant required by each indoor unit 5 can be appropriately distributed.

以下、図２〜５を用いて本発明に関わる処理について詳細に説明する。尚、図２〜４に示すフローチャートでは、ＳＴは処理のステップを表し、これに続く数字はステップ番号を表している。また、図２〜５では、本発明に関わる処理を中心に説明しており、空気調和装置１が冷房運転や除霜運転を行うときの処理や、使用者の指示した設定温度や風量などの運転条件に対応した冷媒回路１０の制御、等といった一般的な処理については説明を省略する。   Hereinafter, the processing according to the present invention will be described in detail with reference to FIGS. In the flowcharts shown in FIGS. 2 to 4, ST represents a processing step, and a number following this represents a step number. FIGS. 2 to 5 mainly describe processes related to the present invention, such as processes when the air-conditioning apparatus 1 performs a cooling operation or a defrosting operation, and a setting temperature or air volume specified by a user. Description of general processing such as control of the refrigerant circuit 10 corresponding to the operating conditions will be omitted.

図２のフローチャートによる処理は、ユーザがいずれかの室内機５に対して運転開始若しくは運転停止を指示する操作を行い、サーモオン状態の室内機５の台数が変化したら開始する。ＣＰＵ２１０は、各室外膨張弁２４の現在の開度を検出し、これに基づいて各室外膨張弁２４の開度流量Ｆａａ〜Ｆａｄおよびその合計値Ｆｓｕｍを算出する（ＳＴ１）。ここで、開度流量Ｆａは、膨張弁の入口側と出口側とが所定の圧力差の場合において、その開度で室外膨張弁２４を通過する冷媒循環量を示す。開度流量Ｆａは、試験等により求めた室外膨張弁２４の開度との相関関係が予め記憶部２２０に記憶されており、これを基に算出される。   The process according to the flowchart of FIG. 2 is started when the user performs an operation of instructing one of the indoor units 5 to start or stop the operation, and the number of the indoor units 5 in the thermo-on state changes. The CPU 210 detects the current opening degree of each outdoor expansion valve 24, and calculates the opening degree flow rates Faa to Fad of each outdoor expansion valve 24 and the total value Fsum thereof based on this (ST1). Here, the opening flow rate Fa indicates the amount of refrigerant circulating through the outdoor expansion valve 24 at the opening when the inlet and outlet sides of the expansion valve have a predetermined pressure difference. The opening degree flow rate Fa has a correlation with the opening degree of the outdoor expansion valve 24 obtained by a test or the like stored in the storage unit 220 in advance, and is calculated based on this.

ＳＴ１の処理を終えたＣＰＵ２１０は、現在の圧縮機２１の回転数Ｎを検出して記憶部２２０にＮ１として記憶する（ＳＴ２）。   After finishing the processing in ST1, the CPU 210 detects the current rotational speed N of the compressor 21 and stores it as N1 in the storage unit 220 (ST2).

その後、ＣＰＵ２１０は、サーモオン状態の室内機５の台数が増加したか否かを判定する（ＳＴ３）。台数が増加していた場合（ＳＴ３−ＹＥＳ）、ＣＰＵ２１０はＳＴ４に処理を進め、図３の増加時制御へ移行する。増加時制御へ移行するとき、圧縮機２１の回転数は増加する。台数が増加していない、つまり、減少していた場合（ＳＴ３−ＮＯ）、ＣＰＵ２１０はＳＴ５に処理を進め、図４の減少時制御へ移行する。減少時制御へ移行するとき、圧縮機２１の回転数は減少する。   Thereafter, CPU 210 determines whether or not the number of indoor units 5 in the thermo-on state has increased (ST3). If the number has increased (ST3-YES), the CPU 210 advances the process to ST4, and shifts to the increase control of FIG. When shifting to the increase control, the rotation speed of the compressor 21 increases. If the number has not increased, that is, has decreased (ST3-NO), the CPU 210 advances the process to ST5, and shifts to the decrease control of FIG. When shifting to the control at the time of decrease, the rotation speed of the compressor 21 decreases.

（１）増加時制御
ＳＴ４の増加時制御について図３と図５（Ａ）を用いて説明する。図３は増加時制御における制御フローを示しており、図５（Ａ）は増加時制御による各室外膨張弁の開度流量Ｆａの変化を示す表である。なお、図５に記載されている数値は概念的なものを示している。図３の増加時制御では、ＣＰＵ２１０は、台数変化時点で既に運転停止（サーモオフ状態）であって、台数変化後においても運転停止である室内機５に対応する室外膨張弁２４の台数変化後開度流量Ｆｂとして、台数変化前の開度流量Ｆａをそのまま割り当てる（ＳＴＢ１）。図５（Ａ）において、台数変化時点で既に運転停止（サーモオフ状態）であって、台数変化後においても運転停止となる室内機である室内機５ｄの台数変化前開度流量Ｆａｄ＝１を室内機５ｄの台数変化後開度流量Ｆｂｄにそのまま割り当てる。 (1) Increase Control The increase control of ST4 will be described with reference to FIG. 3 and FIG. FIG. 3 shows a control flow in the control at the time of increase, and FIG. 5A is a table showing a change in the opening flow rate Fa of each outdoor expansion valve by the control at the time of increase. The numerical values shown in FIG. 5 are conceptual ones. In the control at the time of increase in FIG. 3, the CPU 210 opens after the number of outdoor expansion valves 24 corresponding to the indoor unit 5 that has already stopped operation (thermo-off state) at the time of the number change and has stopped operation even after the number change. The opening degree flow rate Fa before the number change is directly assigned as the degree flow rate Fb (STB1). In FIG. 5A, the operation flow is already stopped (the thermo-off state) at the time of the change in the number of units, and the opening flow rate Fad = 1 before the change in the number of the indoor units 5 d, which is the indoor unit that is stopped even after the change in the number of units, It is directly allocated to the opening flow rate Fbd after the number change of 5d.

次に、ＣＰＵ２１０は、台数変化時点で既に運転停止（サーモオフ状態）であって、台数変化後においても運転停止である室内機５に対応する室外膨張弁２４の開度流量Ｆａの合計値である停止機合計値Ｆｏｆｆを算出するとともに、運転機合計値Ｆｏｎ（＝Ｆｓｕｍ−Ｆｏｆｆ）を算出する（ＳＴＢ２）。   Next, the CPU 210 is the total value of the opening degree flow rate Fa of the outdoor expansion valve 24 corresponding to the indoor unit 5 that has already stopped operation (thermo-off state) at the time of the change in the number of vehicles and has stopped operation after the change in the number of vehicles. A total stopped machine value Foff is calculated, and a total operated machine value Fon (= Fsum-Foff) is calculated (STB2).

次に、ＣＰＵ２１０は、サーモオン状態に移行した室内機５の能力比率ＱＲを算出する（ＳＴＢ３）。能力比率ＱＲは、全てのサーモオン状態の室内機５の能力の合計値に占める当該室内機５の能力の比率であり、ここで、室内機５の能力とは簡易的には各室内機５の定格能力を使用する。これによって、当該室内機５が必要としている冷媒循環量を推定できる。なお、室内温度センサ６２で検出された室内温度や室内ファン５５の回転数等を考慮することで精度を向上させることができる。図５（Ａ）において、運転を開始した室内機５ｃの能力は１０である。また、サーモオン状態の室内機は室内機５ａ、５ｂおよび５ｃであり、各室内機の能力の合計値は２５である。したがって、室内機５ｃの能力比率ＱＲ＝２／５となる。   Next, the CPU 210 calculates the capacity ratio QR of the indoor unit 5 that has shifted to the thermo-on state (STB3). The capacity ratio QR is a ratio of the capacity of the indoor unit 5 to the total value of the capacity of all the indoor units 5 in the thermo-on state. Here, the capacity of the indoor unit 5 is simply the capacity of each indoor unit 5. Use the rated capacity. Thereby, the refrigerant circulation amount required by the indoor unit 5 can be estimated. Note that the accuracy can be improved by taking into consideration the indoor temperature detected by the indoor temperature sensor 62, the number of revolutions of the indoor fan 55, and the like. In FIG. 5A, the capacity of the indoor unit 5c that has started operation is 10. The indoor units in the thermo-on state are the indoor units 5a, 5b, and 5c, and the total value of the capabilities of the indoor units is 25. Therefore, the capacity ratio QR of the indoor unit 5c is 2/5.

また、ＣＰＵ２１０は、台数変化時にサーモオン状態に移行した室内機５に対応する室外膨張弁２４の台数変化後開度流量Ｆｂを算出する。サーモオン状態に移行した室内機５に対応する室外膨張弁２４の台数変化後開度流量Ｆｂは、運転機合計値Ｆｏｎに当該室内機５の能力比率ＱＲを乗算して算出される。図５（Ａ）において、変化前開度流量Ｆａの合計値Ｆｓｕｍ＝２１であり、停止機の合計値Ｆｏｆｆ＝１であるため、運転機の合計値Ｆｏｎ＝２０となる。また、サーモオン状態に移行した室内機５ｃの能力比率ＱＲｃ＝２／５であるため、室内機５ｃの変化後開度流量Ｆｂｃ＝２０＊２／５＝８が割り当てられる。   Further, the CPU 210 calculates the post-change opening flow rate Fb of the outdoor expansion valve 24 corresponding to the indoor unit 5 that has shifted to the thermo-on state when the number changes. The post-change opening flow rate Fb of the number of outdoor expansion valves 24 corresponding to the indoor unit 5 shifted to the thermo-on state is calculated by multiplying the operating unit total value Fon by the capacity ratio QR of the indoor unit 5. In FIG. 5A, since the total value Fsum of the pre-change opening flow rate Fa is 21 and the total value Foff of the stop device is 1, the total value Fon of the operating device is 20. Further, since the capacity ratio QRc of the indoor unit 5c shifted to the thermo-on state is 2/5, the post-change opening flow rate Fbc = 20 * 2/5 = 8 of the indoor unit 5c is assigned.

さらに、ＣＰＵ２１０は、運転機合計値Ｆｏｎからサーモオン状態に移行した室内機５に対応する室外膨張弁２４の台数変化後開度流量Ｆｂを減じた値Ｆｏｎ’を算出し、記憶部２２０に記憶させる。図５（Ａ）において、運転機の合計値Ｆｏｎ＝２０であり、サーモオン状態に移行した室内機５ｃの変化後開度流量Ｆｂｃ＝８であるため、Ｆｏｎ’＝１２となる。   Further, the CPU 210 calculates a value Fon ′, which is obtained by subtracting the post-change opening flow rate Fb of the number of the outdoor expansion valves 24 corresponding to the indoor unit 5 shifted to the thermo-on state from the operating machine total value Fon, and stores the value in the storage unit 220. . In FIG. 5A, since the total value Fon of the operating units is 20 and the post-change opening flow rate Fbc of the indoor unit 5c that has shifted to the thermo-on state is Fbc = 8, Fon '= 12.

ＳＴＢ３の処理を終えたＣＰＵ２１０は、台数変化時に既にサーモオン状態だった室内機５に対応する室外膨張弁２４各々の開度流量比率ＦＲを算出する（ＳＴＢ４）。台数変化時に既にサーモオン状態だった室内機５に対応する室外膨張弁２４の開度流量比率ＦＲは、当該台数変化時に既にサーモオン状態だった室内機５に対応する室外膨張弁２４の開度流量Ｆａが、台数変化時に既にサーモオン状態だった室内機５に対応する室外膨張弁２４の開度流量Ｆａの合計値に占める比率である。図５（Ａ）において、台数変化時に既にサーモオン状態だった室内機は室内機５ａと５ｂである。室内機５ａに対応する室外膨張弁の開度流量Ｆａａ＝１２であり、室内機５ｂに対応する室外膨張弁の開度流量Ｆａｂ＝６である。したがって、室内機５ａに対応する室外膨張弁２４ａの開度流量比率ＦＲａ＝１２／（１２＋６）＝２／３となり、室内機５ｂに対応する室外膨張弁２４ｂの開度流量比率ＦＲｂ＝６／（１２＋６）＝１／３となる。   After finishing the process of STB3, the CPU 210 calculates the opening flow rate ratio FR of each of the outdoor expansion valves 24 corresponding to the indoor units 5 that were already in the thermo-on state at the time of the change in the number of units (STB4). The opening flow rate FR of the outdoor expansion valve 24 corresponding to the indoor unit 5 already in the thermo-on state at the time of the change in the number is the opening flow rate Fa of the outdoor expansion valve 24 corresponding to the indoor unit 5 already in the thermo-on state at the time of the change in the number. Is the ratio of the open flow rate Fa of the outdoor expansion valve 24 corresponding to the indoor unit 5 already in the thermo-on state at the time of the change in the total number to the total value. In FIG. 5A, the indoor units already in the thermo-on state at the time of the change in the number are the indoor units 5a and 5b. The opening flow rate Faa of the outdoor expansion valve corresponding to the indoor unit 5a is Faa = 12, and the opening flow rate Fab of the outdoor expansion valve corresponding to the indoor unit 5b is Fab = 6. Therefore, the opening flow rate ratio FRa of the outdoor expansion valve 24a corresponding to the indoor unit 5a is 12 / (12 + 6) = 2/3, and the opening flow rate ratio FRb = 6 / (of the outdoor expansion valve 24b corresponding to the indoor unit 5b. 12 + 6) = 1/3.

また、ＣＰＵ２１０は、台数変化時に既にサーモオン状態だった室内機５に対応する室外膨張弁２４各々の台数変化後開度流量Ｆｂを算出する。台数変化時に既にサーモオン状態だった室内機５に対応する室外膨張弁２４の台数変化後開度流量Ｆｂは、ＳＴＢ３で算出したＦｏｎ’に当該室内機５の開度流量比率ＦＲを乗算して算出される。図５（Ａ）において、Ｆｏｎ’＝１２であり、室内機５ａの開度流量比率ＦＲａ＝２／３であり、室内機５ｂの開度流量比率ＦＲｂ＝１／３である。したがって、室内機５ａに対応する室外膨張弁２４ａの台数変化後開度流量Ｆｂａ＝１２＊２／３＝８となり、室内機５ｂに対応する室外膨張弁２４ｂの台数変化後開度流量Ｆｂｂ＝１２＊１／３＝４となる。   Further, the CPU 210 calculates the post-change opening flow rate Fb of each of the outdoor expansion valves 24 corresponding to the indoor units 5 already in the thermo-on state at the time of the change in the number. The post-change opening flow rate Fb of the outdoor expansion valve 24 corresponding to the indoor unit 5 already in the thermo-on state at the time of the change in the number is calculated by multiplying the Fon 'calculated in STB3 by the opening flow rate ratio FR of the indoor unit 5 concerned. Is done. In FIG. 5A, Fon '= 12, the opening flow rate ratio FRa of the indoor unit 5a is 2/3, and the opening flow rate ratio FRb of the indoor unit 5b is 1/3. Therefore, the post-change opening flow rate Fba = 12 * 2/3 = 8 of the number of outdoor expansion valves 24a corresponding to the indoor unit 5a, and the post-change opening flow rate Fbb = 12 of the outdoor expansion valves 24b corresponding to the indoor unit 5b. * 1/3 = 4.

ＳＴＢ４の処理が終わるまでに、全ての室内機５に対応する室外膨張弁２４の台数変化後開度流量Ｆｂが算出される。台数変化後開度流量Ｆｂの合計値と台数変化前開度流量Ｆａの合計値を比較すると同じ値となり、運転台数が変化しても各室内機５で必要としている冷媒循環量を適切に分配できる開度に早く安定させることができる。図５（Ａ）において、台数変化後開度流量Ｆｂの合計値と台数変化前開度流量Ｆａの合計値は２１で同じ値となっている。   By the end of the process of STB4, the post-change opening flow rate Fb of the number of outdoor expansion valves 24 corresponding to all the indoor units 5 is calculated. Comparing the total value of the post-change opening flow rate Fb with the total value of the pre-change opening flow rate Fa results in the same value, so that even if the number of operating units changes, the refrigerant circulation amount required by each indoor unit 5 can be appropriately distributed. The opening can be stabilized quickly. In FIG. 5A, the total value of the post-unit-change opening flow rate Fb and the total value of the pre-unit-change opening flow amount Fa are 21 and are the same value.

ＳＴＢ４の処理を終えたＣＰＵ２１０は、算出した室内機５に対応する室外膨張弁２４の台数変化後開度流量Ｆｂを室外膨張弁２４の開度に変換し、当該開度となるように各室外膨張弁２４の開度制御を行う（ＳＴＢ５）。なお、開度流量Ｆａと室外膨張弁２４の開度との相関関係は予め記憶部２２０に記憶されている。   After finishing the process of STB4, the CPU 210 converts the calculated opening flow rate Fb of the number of the outdoor expansion valves 24 corresponding to the indoor unit 5 into the opening degree of the outdoor expansion valve 24, and adjusts each outdoor unit to the opening degree. The opening degree of the expansion valve 24 is controlled (STB5). The correlation between the opening degree flow rate Fa and the opening degree of the outdoor expansion valve 24 is stored in the storage unit 220 in advance.

ＳＴＢ５の処理を終えたＣＰＵ２１０は、圧縮機２１の回転数Ｎが所定回転数Ｎｔｇに到達したか否かを判定する（ＳＴＢ６）。所定回転数Ｎｔｇは、全ての室内機５から要求された能力を発揮するための目標となる回転数である。圧縮機２１の回転数Ｎが所定回転数Ｎｔｇに到達していた場合（ＳＴＢ６−ＹＥＳ）、増加時制御を終了する。圧縮機２１の回転数Ｎが所定回転数Ｎｔｇに到達していない場合（ＳＴＢ６−ＮＯ）、圧縮機２１の回転数Ｎが図２のＳＴ２の時点で検出した圧縮機２１の回転数Ｎ１から１０％増加したか否かを判定する（ＳＴＢ７）。回転数Ｎ１から１０％増加していなかった場合（ＳＴＢ７−ＮＯ）、ＳＴＢ６へ処理を戻す。   After finishing the process of STB5, the CPU 210 determines whether or not the rotation speed N of the compressor 21 has reached a predetermined rotation speed Ntg (STB6). The predetermined rotation speed Ntg is a rotation speed that is a target for exhibiting the performance requested by all the indoor units 5. If the rotation speed N of the compressor 21 has reached the predetermined rotation speed Ntg (STB6-YES), the increase control is ended. If the rotation speed N of the compressor 21 has not reached the predetermined rotation speed Ntg (STB6-NO), the rotation speed N of the compressor 21 is reduced from the rotation speed N1 of the compressor 21 detected at ST2 in FIG. % Is determined (STB7). If the rotation speed has not increased by 10% from N1 (STB7-NO), the process returns to STB6.

圧縮機２１の回転数Ｎが図２のＳＴ２の時点で検出した圧縮機２１の回転数Ｎ１から１０％増加していた場合（ＳＴＢ７−ＹＥＳ）、室内機５に対応する室外膨張弁２４の台数変化後開度流量Ｆｂを圧縮機２１の回転数Ｎに合わせて１０％増加させ、増加させた台数変化後開度流量Ｆｂを室外膨張弁２４の開度に変換し、当該開度となるように各室外膨張弁２４の開度制御を行う（ＳＴＢ８）。
その後、回転数Ｎ１を更新してＳＴＢ６へ処理を戻し、圧縮機２１の回転数Ｎが所定回転数Ｎｔｇとなるまでこの処理を繰り返す。 When the rotation speed N of the compressor 21 has increased by 10% from the rotation speed N1 of the compressor 21 detected at the time of ST2 in FIG. 2 (STB7-YES), the number of the outdoor expansion valves 24 corresponding to the indoor units 5 The post-change opening flow rate Fb is increased by 10% in accordance with the rotation speed N of the compressor 21, and the increased post-change opening flow rate Fb is converted into the opening degree of the outdoor expansion valve 24 so as to be the opening degree. Next, the opening degree of each outdoor expansion valve 24 is controlled (STB8).
Thereafter, the rotation speed N1 is updated and the process returns to STB6, and this process is repeated until the rotation speed N of the compressor 21 reaches the predetermined rotation speed Ntg.

（２）減少時制御
ＳＴ５の減少時制御について図４と図５（Ｂ）を用いて説明する。図４は減少時制御における制御フローを示しており、図５（Ｂ）は減少時制御による各室外膨張弁の開度流量Ｆａの変化を示す表である。図４の減少時制御では、ＣＰＵ２１０は、台数変化時点で既に運転停止（サーモオフ状態）であって、台数変化後においても運転停止である室内機５に対応する室外膨張弁２４の台数変化後開度流量Ｆｂとして、台数変化前の開度流量Ｆａをそのまま割り当てる（ＳＴＣ１）。図５（Ｂ）において、台数変化時点で既に運転停止（サーモオフ状態）であって、台数変化後においても運転停止となる室内機である室内機５ｄの台数変化前開度流量Ｆａｄ＝１を室内機５ｄの台数変化後開度流量Ｆｂｄにそのまま割り当てる。また、ＣＰＵ２１０は、台数変化時に運転停止した室内機５に対応する室外膨張弁２４の台数変化後開度流量Ｆｂに所定値αを割り当てる。所定値αは、運転停止中の室内機の初期開度に相当する開度流量であって、冷房運転時においては０であり、暖房運転時においては室内熱交換器に冷媒が溜らない程度の微小な開度流量である。図５（Ｂ）において、所定値α＝１であり、台数変化時に運転停止した室内機５ｃに対応する室外膨張弁２４ｃの台数変化後開度流量Ｆｂｃ＝１を割り当てる。 (2) Control at the time of decrease The control at the time of decrease in ST5 will be described with reference to FIGS. 4 and 5B. FIG. 4 shows a control flow in the control at the time of decrease, and FIG. 5B is a table showing a change in the opening flow rate Fa of each outdoor expansion valve by the control at the time of decrease. In the control at the time of decrease in FIG. 4, the CPU 210 opens after the number of outdoor expansion valves 24 corresponding to the indoor unit 5 that has already stopped operation (thermo-off state) at the time of the number change and has stopped operation after the number change. The opening degree flow rate Fa before the number change is directly assigned as the degree flow rate Fb (STC1). In FIG. 5 (B), the operation flow is already stopped (thermo-off state) at the time of the change in the number of units, and the opening flow rate Fad = 1 before the change in the number of the indoor units 5d, which is the indoor unit that is stopped even after the change in the number of units, It is directly allocated to the opening flow rate Fbd after the number change of 5d. Further, the CPU 210 assigns a predetermined value α to the post-change opening flow rate Fb of the number of the outdoor expansion valves 24 corresponding to the indoor units 5 whose operation has been stopped at the time of changing the number. The predetermined value α is an opening flow rate corresponding to the initial opening degree of the indoor unit during the operation stop, and is 0 during the cooling operation, and is such that the refrigerant does not accumulate in the indoor heat exchanger during the heating operation. This is a minute opening flow rate. In FIG. 5B, the predetermined value α = 1, and the post-change opening flow rate Fbc = 1 of the outdoor expansion valve 24c corresponding to the indoor unit 5c whose operation has been stopped at the time of changing the number is assigned.

次に、ＣＰＵ２１０は、台数変化後に運転停止（サーモオフ状態）となる室内機５に対応する室外膨張弁２４の変化後開度流量Ｆｂの合計値である停止機合計値Ｆｏｆｆを算出するとともに、運転機合計値Ｆｏｎ（＝Ｆｓｕｍ−Ｆｏｆｆ）を算出する（ＳＴＣ２）。図５（Ｂ）において、台数変化後に運転停止（サーモオフ状態）となる室内機５は室内機５ｃと室内機５ｄである。室内機５ｃに対応する室外膨張弁２４ｃの開度流量Ｆｂｃと室内機５ｄに対応する室外膨張弁２４ｄの開度流量Ｆｂｄはともに１である。したがって、停止機合計値Ｆｏｆｆ＝１＋１＝２である。また、図５（Ｂ）において、各室外膨張弁２４の開度流量Ｆａａ〜ｄの合計値Ｆｓｕｍ＝２０である。したがって、運転機合計値Ｆｏｎ＝２０−２＝１８となる。   Next, the CPU 210 calculates the stop unit total value Foff, which is the total value of the post-change opening flow rate Fb of the outdoor expansion valve 24 corresponding to the indoor unit 5 whose operation is stopped (thermo-off state) after the change in the number of units. A total machine value Fon (= Fsum-Foff) is calculated (STC2). In FIG. 5 (B), the indoor units 5 whose operation is stopped (thermo-off state) after the change in the number of units are the indoor unit 5c and the indoor unit 5d. The opening flow rate Fbc of the outdoor expansion valve 24c corresponding to the indoor unit 5c and the opening flow rate Fbd of the outdoor expansion valve 24d corresponding to the indoor unit 5d are both 1. Therefore, the total stop machine value Foff = 1 + 1 = 2. In FIG. 5B, the sum Fsum = 20 of the opening flow rates Faa to d of the outdoor expansion valves 24 is 20. Therefore, the driving machine total value Fon = 20-2 = 18.

ＳＴＣ２の処理を終えたＣＰＵ２１０は、台数変化時に既にサーモオン状態であって、台数変化後も運転を継続する室内機５に対応する室外膨張弁２４各々の開度流量比率ＦＲを算出する（ＳＴＣ３）。台数変化時に既にサーモオン状態であって、台数変化後も運転を継続する室内機５に対応する室外膨張弁２４の開度流量比率ＦＲは、当該台数変化時に既にサーモオン状態であって、台数変化後も運転を継続する室内機５に対応する室外膨張弁２４の開度流量Ｆａが、台数変化時に既にサーモオン状態であって、台数変化後も運転を継続する室内機５に対応する室外膨張弁２４の開度流量Ｆａの合計値に占める比率である。図５（Ｂ）において、台数変化時に既にサーモオン状態であって、台数変化後も運転を継続する室内機は室内機５ａと５ｂである。室内機５ａに対応する室外膨張弁の開度流量Ｆａａ＝８であり、室内機５ｂに対応する室外膨張弁の開度流量Ｆａｂ＝４である。したがって、室内機５ａに対応する室外膨張弁２４ａの開度流量比率ＦＲａ＝８／（８＋４）＝２／３となり、室内機５ｂに対応する室外膨張弁２４ｂの開度流量比率ＦＲｂ＝４／（８＋４）＝１／３となる。   The CPU 210 that has completed the processing of STC2 calculates the opening flow rate ratio FR of each of the outdoor expansion valves 24 corresponding to the indoor units 5 that are already in the thermo-on state at the time of the change in the number and continue to operate even after the change in the number (STC3). . The opening degree flow rate FR of the outdoor expansion valve 24 corresponding to the indoor unit 5 that is already in the thermo-on state when the number of units changes and continues to operate even after the number of units changes is already in the thermo-on state when the number of units changes, and The opening degree flow rate Fa of the outdoor expansion valve 24 corresponding to the indoor unit 5 that continues to operate is already in the thermo-on state when the number of units changes, and the outdoor expansion valve 24 corresponding to the indoor unit 5 that continues operation after the number of units changes. Is a ratio of the opening degree flow rate Fa to the total value. In FIG. 5B, the indoor units that are already in the thermo-on state when the number of units changes and continue to operate even after the number of units change are the indoor units 5a and 5b. The opening flow rate Faa of the outdoor expansion valve corresponding to the indoor unit 5a is 8, and the opening flow rate Fab of the outdoor expansion valve corresponding to the indoor unit 5b is 4. Therefore, the opening flow rate ratio FRa = 8 / (8 + 4) = 2/3 of the outdoor expansion valve 24a corresponding to the indoor unit 5a, and the opening flow rate ratio FRb = 4 / (of the outdoor expansion valve 24b corresponding to the indoor unit 5b. 8 + 4) = 1/3.

また、ＣＰＵ２１０は、台数変化時に既にサーモオン状態であって、台数変化後も運転を継続する室内機５に対応する室外膨張弁２４各々の台数変化後開度流量Ｆｂを算出する。台数変化時に既にサーモオン状態であって、台数変化後も運転を継続する室内機５に対応する室外膨張弁２４の台数変化後開度流量Ｆｂは、ＳＴＣ２で算出したＦｏｎに当該室内機５の開度流量比率ＦＲを乗算して算出される。図５（Ｂ）において、Ｆｏｎ＝１８であり、室内機５ａの開度流量比率ＦＲａ＝２／３であり、室内機５ｂの開度流量比率ＦＲｂ＝１／３である。したがって、室内機５ａに対応する室外膨張弁２４ａの台数変化後開度流量Ｆｂａ＝１８＊２／３＝１２となり、室内機５ｂに対応する室外膨張弁２４ｂの台数変化後開度流量Ｆｂｂ＝１８＊１／３＝６となる。   Further, the CPU 210 calculates the post-unit-change opening flow rate Fb of each of the outdoor expansion valves 24 corresponding to the indoor units 5 that are already in the thermo-on state when the number of units changes and continue to operate even after the unit number changes. The post-change opening flow rate Fb of the outdoor expansion valve 24 corresponding to the indoor unit 5 which is already in the thermo-on state at the time of the change in the number of units and continues to operate even after the change in the number of units, is set to Fon calculated in STC2. It is calculated by multiplying the flow rate ratio FR. In FIG. 5B, Fon = 18, the opening flow rate ratio FRa of the indoor unit 5a is 2/3, and the opening flow rate ratio FRb of the indoor unit 5b is 1/3. Therefore, the post-change opening flow rate Fba = 18 * 2/3 = 12 of the number of outdoor expansion valves 24a corresponding to the indoor unit 5a, and the post-change opening flow rate Fbb = 18 of the outdoor expansion valves 24b corresponding to the indoor unit 5b. * 1/3 = 6.

ＳＴＢ３の処理が終わるまでに、全ての室内機５に対応する室外膨張弁２４の台数変化後開度流量Ｆｂが算出される。台数変化後開度流量Ｆｂの合計値と台数変化前開度流量の合計値を比較すると同じ値となり、運転台数が変化しても各室内機５で必要としている冷媒循環量を適切に分配できる開度に早く安定させることができる。図５（Ｂ）において、台数変化後開度流量Ｆｂの合計値と台数変化前開度流量の合計値は２０で同じ値となっている。   By the end of the process of STB3, the post-change opening flow rate Fb of the number of outdoor expansion valves 24 corresponding to all the indoor units 5 is calculated. Comparing the total value of the opening flow rate Fb after the number change and the total value of the opening flow rate before the number change result in the same value, so that even if the number of operating units changes, the refrigerant circulation amount required by each indoor unit 5 can be appropriately distributed. Can be stabilized quickly every time. In FIG. 5B, the total value of the post-unit-change opening flow rate Fb and the total value of the pre-unit-change opening flow amount Fb are the same value of 20.

ＳＴＣ３の処理を終えたＣＰＵ２１０は、算出した室内機５に対応する室外膨張弁２４の台数変化後開度流量Ｆｂを室外膨張弁２４の開度に変換し、当該開度となるように各室外膨張弁２４の開度制御を行う（ＳＴＣ４）。なお、開度流量Ｆａと室外膨張弁２４の開度との相関関係は予め記憶部２２０に記憶されている。   The CPU 210 that has completed the processing of the STC 3 converts the calculated opening flow rate Fb of the number of the outdoor expansion valves 24 corresponding to the indoor unit 5 into the opening degree of the outdoor expansion valve 24, and sets each outdoor unit so as to have the opening degree. The opening degree of the expansion valve 24 is controlled (STC4). The correlation between the opening degree flow rate Fa and the opening degree of the outdoor expansion valve 24 is stored in the storage unit 220 in advance.

ＳＴＣ４の処理を終えたＣＰＵ２１０は、圧縮機２１の回転数Ｎが所定回転数Ｎｔｇに到達したか否かを判定する（ＳＴＣ５）。所定回転数Ｎｔｇは、全ての室内機５から要求された能力を発揮するための目標となる回転数である。圧縮機２１の回転数Ｎが所定回転数Ｎｔｇに到達していた場合（ＳＴＣ５−ＹＥＳ）、減少時制御を終了する。圧縮機２１の回転数Ｎが所定回転数Ｎｔｇに到達していない場合（ＳＴＣ５−ＮＯ）、圧縮機２１の回転数Ｎが図２のＳＴ２の時点で検出した圧縮機２１の回転数Ｎ１から１０％減少したか否かを判定する（ＳＴＣ６）。回転数Ｎ１から１０％減少していなかった場合（ＳＴＣ６−ＮＯ）、ＳＴＣ５へ処理を戻す。   After finishing the processing of STC4, CPU 210 determines whether or not rotation speed N of compressor 21 has reached predetermined rotation speed Ntg (STC5). The predetermined rotation speed Ntg is a rotation speed that is a target for exhibiting the performance requested by all the indoor units 5. When the rotation speed N of the compressor 21 has reached the predetermined rotation speed Ntg (STC5-YES), the control at the time of decrease is ended. When the rotation speed N of the compressor 21 has not reached the predetermined rotation speed Ntg (STC5-NO), the rotation speed N of the compressor 21 is reduced by 10 from the rotation speed N1 of the compressor 21 detected at ST2 in FIG. % Is determined (STC6). If the rotational speed has not decreased by 10% from N1 (STC6-NO), the process returns to STC5.

圧縮機２１の回転数Ｎが図２のＳＴ２の時点で検出した圧縮機２１の回転数Ｎ１から１０％減少していた場合（ＳＴＣ６−ＹＥＳ）、室内機５に対応する室外膨張弁２４の台数変化後開度流量Ｆｂを圧縮機２１の回転数Ｎに合わせて１０％減少させ、減少させた台数変化後開度流量Ｆｂを室外膨張弁２４の開度に変換し、当該開度となるように各室外膨張弁２４の開度制御を行う（ＳＴＣ７）。
その後、回転数Ｎ１を更新してＳＴＣ５へ処理を戻し、圧縮機２１の回転数Ｎが所定回転数Ｎｔｇとなるまでこの処理を繰り返す。 When the rotation speed N of the compressor 21 has decreased by 10% from the rotation speed N1 of the compressor 21 detected at the time of ST2 in FIG. 2 (STC6-YES), the number of the outdoor expansion valves 24 corresponding to the indoor units 5 The post-change opening flow rate Fb is reduced by 10% in accordance with the rotational speed N of the compressor 21, and the reduced post-change opening flow rate Fb is converted into the opening degree of the outdoor expansion valve 24 so that the opening degree is obtained. Next, the opening degree of each outdoor expansion valve 24 is controlled (STC7).
Thereafter, the rotation speed N1 is updated and the process returns to STC5, and this process is repeated until the rotation speed N of the compressor 21 reaches the predetermined rotation speed Ntg.

なお、室内機５の運転台数が変化する際に圧力変動が生じる。そのため、この圧力変動を考慮して変化後の膨張弁開度を設定してもよい。つまり、本実施例において、変化後開度流量Ｆｂを割り当てる際に、変化後開度流量Ｆｂに室内機能力に応じた補正値を加えることでより適正な開度を設定することができる。   Note that when the number of operating indoor units 5 changes, pressure fluctuations occur. Therefore, the changed expansion valve opening may be set in consideration of the pressure fluctuation. That is, in this embodiment, when assigning the post-change opening flow rate Fb, a more appropriate opening degree can be set by adding a correction value according to the indoor functional power to the post-change opening flow rate Fb.

以上説明した実施形態によれば、運転台数が変化しても各室内機５で必要としている冷媒循環量を適切に分配できる開度に早く安定させることができる。   According to the embodiment described above, it is possible to quickly stabilize the opening degree at which the amount of circulating refrigerant required by each indoor unit 5 can be appropriately distributed even if the number of operating units changes.

１ 空気調和装置
２ 室外機
５ａ〜５ｃ 室内機
８ａ〜８ｃ第１〜第３液管
２３ 室外熱交換器
２４ａ 第１室外膨張弁
２４ｂ 第２室外膨張弁
２４ｃ 第３室外膨張弁
３１ 高圧センサ
３２ 低圧センサ
３３ 吐出温度センサ
３４ 吸入温度センサ
３５ 室外熱交温度センサ

DESCRIPTION OF SYMBOLS 1 Air conditioner 2 Outdoor unit 5a-5c Indoor unit 8a-8c 1st-3rd liquid pipe 23 Outdoor heat exchanger 24a 1st outdoor expansion valve 24b 2nd outdoor expansion valve 24c 3rd outdoor expansion valve 31 High pressure sensor 32 Low pressure Sensor 33 Discharge temperature sensor 34 Intake temperature sensor 35 Outdoor heat exchange temperature sensor

Claims (3)

一台の室外機に対して、室内熱交換器を有する室内機を複数台接続し、当該各室内機を個別に運転可能とした空気調和装置において、
サーモオン状態の前記室内機の台数が変化したとき、
前記室内機の運転台数変化前の前記各室内機に対応する膨張弁の開度からそれぞれの開度流量を算出し、
サーモオン状態の前記室内機の台数が変化する直前の前記開度流量の合計値を維持するように前記各膨張弁を開度制御することを特徴とする空気調和装置。 In one air conditioner, in an air conditioner in which a plurality of indoor units having an indoor heat exchanger are connected and each of the indoor units can be individually operated,
When the number of the indoor units in the thermo-on state changes,
Calculate the respective opening degree flow rates from the opening degrees of the expansion valves corresponding to the respective indoor units before the change in the number of operating indoor units,
An air conditioner, wherein each of the expansion valves is controlled in opening so as to maintain a total value of the opening flow rates immediately before the number of the indoor units in the thermo-on state changes. 前記室内機の運転台数変化時に新たにサーモオン状態に移行した前記室内機に対応する前記膨張弁は、当該新たにサーモオン状態に移行した前記室内機の能力が前記マルチタイプ空気調和機全体の能力に占める比率と前記開度流量の合計値に基づいて定められる開度となるように制御されることを特徴とする請求項１に記載の空気調和装置。   The expansion valve corresponding to the indoor unit that has newly transitioned to the thermo-on state when the number of operating indoor units changes, the capacity of the indoor unit that has newly transitioned to the thermo-on state corresponds to the capacity of the entire multi-type air conditioner. The air conditioner according to claim 1, wherein the air conditioner is controlled so as to have an opening determined based on a ratio of the occupation ratio and a total value of the opening flow rates. 前記室内機の運転台数変化後、前記室外機に備えられる圧縮機の回転数の変化率に応じて前記各開度流量を算出し、算出した前記各開度流量となるように前記各膨張弁の開度を制御することを特徴とする請求項１又は２に記載の空気調和装置。   After the change in the number of operating indoor units, the respective opening flow rates are calculated in accordance with the rate of change in the number of revolutions of the compressor provided in the outdoor unit, and the respective expansion valves are set to the calculated opening flow rates. The air conditioner according to claim 1 or 2, wherein the opening degree of the air conditioner is controlled.

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