JP3883725B2

JP3883725B2 - Method of operating air conditioner and air conditioner

Info

Publication number: JP3883725B2
Application number: JP02218099A
Authority: JP
Inventors: 公二永江
Original assignee: Sanyo Electric Co Ltd
Current assignee: Sanyo Electric Co Ltd
Priority date: 1999-01-29
Filing date: 1999-01-29
Publication date: 2007-02-21
Anticipated expiration: 2019-01-29
Also published as: JP2000220894A

Description

【０００１】
【発明の属する技術分野】
本発明は、複数台の室外機を備えた空気調和装置の運転方法及び空気調和装置に関する。
【０００２】
【従来の技術】
空気調和装置には、一般に、それぞれに圧縮機を備えた複数台の室外機と、複数台の室内機とが並列に接続されたものがある。上記圧縮機は、その容量（能力）を制御可能な容量可変型圧縮機と、容量制御が不可能な定速型圧縮機とがあり、上記各室外機には、これらのいずれかのタイプの圧縮機が装備されている。
【０００３】
ところで、上述のような空気調和装置を冷房又は暖房運転させた時には、室外機のうち一台が停止状態にあると、その停止室外機に冷媒が滞留して、他の運転中の室外機に冷媒が不足する場合がある。
【０００４】
このような場合の空気調和装置の運転方法として、冷媒が滞留した室外機を停止状態に維持したままで、その停止室外機のアキュムレータ、レシーバタンクまたは室外熱交換器から電磁弁などを開操作して、滞留している冷媒を冷媒が不足した室外機へ供給している。
【０００５】
ここで、冷媒が滞留した室外機を停止状態とするのは、当該室外機の圧縮機が例えば定速型圧縮機である場合、この室外機を運転させると、室内機の運転台数に対し、空気調和装置全体における室外機の能力が過剰となってしまうからである。
【０００６】
【発明が解決しようとする課題】
しかしながら、上述のような運転方法によって、冷媒が不足した室外機へ冷媒を供給する場合には、冷媒が滞留した室外機が停止状態であるため、室外機の冷媒不足を解消するのに長時間を要してしまう。
【０００７】
本発明の目的は、上述の事情を考慮してなされたものであり、冷媒が不足した室外機へ迅速に冷媒を供給できる空気調和装置を提供することにある。
【０００８】
【課題を解決するための手段】
請求項１に記載の発明は、複数台の室外機が並列に室内機に接続されると共に、夫々の室外熱交換器の温度検出並びに室外膨張弁の開度に基づく夫々の室外機の冷媒不足判断手段を備えた空気調和装置の運転方法において、上記室外機が備える圧縮機は容量制御可能な圧縮機であり、室内機の運転状態に対応してその容量が変更されるとともに、運転状態にある上記室外機のうちの少なくとも一台に冷媒が不足したとき、停止状態で冷媒が滞留した上記室外機を運転させるよう制御することを特徴とするものである。
【０００９】
請求項２に記載の発明は、請求項１に記載の発明において、停止状態で冷媒が滞留した上記室外機を運転させる際に、冷媒が不足した室外機を停止させることを特徴とするものである。
【００１０】
請求項３に記載の発明は、請求項１に記載の発明において、停止状態で冷媒が滞留した上記室外機を運転させる際に、冷媒が不足した室外機の運転を継続させることを特徴とするものである。
【００１１】
請求項４に記載の発明は、複数台の室外機が並列に室内機に接続されると共に、夫々の室外熱交換器の温度検出並びに室外膨張弁の開度に基づく夫々の室外機の冷媒不足判断手段を備え、これらの室外機及び室内機の運転を制御装置が制御する空気調和装置において、上記室外機が備える圧縮機は容量制御可能な圧縮機であり、上記制御装置により室内機の運転状態に対応して上記圧縮機の容量が変更されるとともに、上記制御装置は、運転状態にある上記室外機のうちの少なくとも一台に冷媒が不足したとき、停止状態で冷媒が滞留した上記室外機を運転させるよう制御することを特徴とするものである。
【００１２】
請求項５に記載の発明は、請求項４に記載の発明において、上記制御装置は、停止状態で冷媒が滞留した室外機を運転させる際に、冷媒が不足した室外機を停止させることを特徴とするものである。
【００１３】
請求項６に記載の発明は、請求項４に記載の発明において、上記制御装置は、停止状態で冷媒が滞留した室外機を運転させる際に、冷媒が不足した室外機の運転を継続させることを特徴とするものである。
【００１４】
請求項１または４に記載の発明には、次の作用がある。
【００１５】
運転状態にある室外機のうちの少なくとも一台に冷媒が不足したとき、停止状態で冷媒が滞留した室外機を運転させるよう制御することから、この運転を開始した室外機に滞留する冷媒を室内機を経て、冷媒が不足した室外機へ迅速に供給することができる。
【００１６】
また、室外機が備える圧縮機は容量制御可能な圧縮機であり、室内機の運転状態に対応してその容量を変更することから、冷媒が不足した室外機へ冷媒を供給するためにたとえ全ての室外機を運転させたときでも、これらの室外機の圧縮機の容量を室内機の運転状態（例えば運転台数）に対応して低下させることができるので、室外機全体としての過剰能力運転を確実に防止できる。
【００１７】
請求項２または５に記載の発明には、次の作用がある。
【００１８】
停止状態で冷媒が滞留した室外機を運転させる際に、冷媒が不足した室外機を停止させることから、空気調和装置全体における室外機の能力を、冷媒が滞留した室外機の運転前の能力とほぼ等しくすることができ、室外機全体としての過剰能力運転を防止できる。
【００１９】
請求項３または６に記載の発明には、次の作用がある。
【００２０】
停止状態で冷媒が滞留した室外機を運転させる際に、冷媒が不足した室外機の運転を継続させることから、全ての室外機が運転状態となるので、空気調和装置の各室外機において冷媒の偏りをなくすことができる。
【００２１】
【発明の実施の形態】
以下、本発明の実施の形態を、図面に基づき説明する。
【００２２】
図１は、本発明に係る空気調和装置の一実施の形態を示す系統図である。
【００２３】
この図１に示す空気調和装置１０は、ガス管１３及び液管１４からなる主冷媒配管１５に対して、複数台の室外機１１Ａ、１１Ｂ・・・が並列に接続され、同じく主冷媒配管１５に対して複数台の室内機１２Ａ、１２Ｂ・・・が並列に接続されて構成されている。これらの室外機１１Ａ、１１Ｂ・・・と室内機１２Ａ、１２Ｂ・・・の設置台数は、空調負荷の量、例えば空気調和装置１０が装備される建物の大きさなどによって設定される。
【００２４】
上記室内機１２Ａ、１２Ｂ・・・は、室内冷媒配管１６に室内膨張弁１７及び室内熱交換器１８が配設されて構成され、室内冷媒配管１６の一端がガス管１３に、他端が液管１４にそれぞれ接続される。
【００２５】
上記室内冷媒配管１６には、室内熱交換器１８の前後に第一室内サーミスタ２７、第二室内サーミスタ２８がそれぞれ設置され、これらにて検出された冷媒温度が、図２に示す制御装置３５へ送信される。この制御装置３５は、空気調和装置１０の冷房又は暖房運転時に、第一室内サーミスタ２７と第二室内サーミスタ２８にて検出された冷媒の温度差が所定温度となるように、上記室内膨張弁１７の開度を制御して空調負荷に対処する。
【００２６】
上記室外機１１Ａ、１１Ｂ・・・は、図２に示すように、室外冷媒配管１９に圧縮機２０が配設され、この圧縮機２０の吸込側にアキュムレータ２１が配設され、吐出側に油分離器２２、四方弁２３が順次配設され、更に、油分離器２２側の室外冷媒配管１９に室外熱交換器２４、室外膨張弁２５、レシーバタンク３８が順次配設されて構成される。室外冷媒配管１９のレシーバタンク３８側端部が、主冷媒配管１５の液管１４に接続される。また、室外冷媒配管１９のアキュムレータ２１側端部は、四方弁２３を介して主冷媒配管１５のガス管１３に接続される。
【００２７】
上記室外冷媒配管１９には、室外熱交換器２４の前後に第一室外サーミスタ２９、第二室外サーミスタ３０がそれぞれ設置され、これらにて検出された冷媒温度が制御装置３５へ送信される。この制御装置３５は、空気調和装置１０の特に暖房運転時に、第一室外サーミスタ２９と第二室外サーミスタ３０にて検出された冷媒の温度差が所定温度となるように、上記室外膨張弁２５の弁開度を制御して空調負荷に対処する。
【００２８】
各室外機１１Ａ、１１Ｂ・・・の圧縮機２０は、内部高圧型圧縮機で、しかも容量（能力）制御可能な容量可変型圧縮機である。この圧縮機２０の運転、停止または容量制御は、制御装置３５により、室内機１２Ａ、１２Ｂ・・・の運転台数などの運転状況に対応して実施される。
上記油分離器２２は、圧縮機２０から吐出されたガス冷媒中の冷凍機油を分離するものであり、室外冷媒配管１９におけるアキュムレータ２１から圧縮機２０へ至る管路（吸込管路）に油戻し管２６を介して接続される。従って、油分離器２２にて分離された冷凍機油は、油戻し管２６を経て室外冷媒配管１９における上記吸込管路、つまり圧縮機２０に適宜戻される。
【００２９】
上記四方弁２３の切換は制御装置３５によりなされ、この切換によって、空気調和装置１０が冷房運転又は暖房運転に設定される。
【００３０】
つまり、四方弁２３が冷房側に切り替えられると、冷媒が実線矢印Ａの如く流れ、各室外機１１Ａ、１１Ｂ・・・の圧縮機２０から吐出された冷媒は、油分離器２２及び四方弁２３を経て室外熱交換器２４に至り、この室外熱交換器２４で凝縮され、室外膨張弁２５及びレシーバタンク３８を経て液管１４で合流し、各室内機１２Ａ、１２Ｂ・・・に分流され、これらの室内機１２Ａ、１２Ｂ・・・の室内膨張弁１７を経て減圧された後、室内熱交換器１８で蒸発されて室内を冷房する。各室内機１２Ａ、１２Ｂ・・・の室内熱交換器１８からの冷媒は、ガス管１３で合流し、各室外機１１Ａ、１１Ｂ・・・に分流され、これらの各室外機１１Ａ、１１Ｂ・・・の四方弁２３及びアキュムレータ２１を経て圧縮機２０に戻される。
【００３１】
また、四方弁２３が暖房側に切り替えられると、冷媒が破線矢印Ｂの如く流れ、各室外機１１Ａ、１１Ｂ・・・の圧縮機２０から吐出された冷媒は、油分離器２２及び四方弁２３を経てガス管１３で合流し、室内機１２Ａ、１２Ｂ・・・で分流して、これら各室内機１２Ａ、１２Ｂ・・・の室内熱交換器１８にて凝縮して室内を暖房する。室内熱交換器１８にて凝縮された冷媒は室内膨張弁１７にて減圧され、液管１４にて合流され、各室外機１１Ａ、１１Ｂ・・・にて分流されて、これら各室外機１１Ａ、１１Ｂ・・・のレシーバタンク３８を経て室外膨張弁２５で再び減圧され、室外熱交換器２４で蒸発された後、四方弁２３及びアキュムレータ２１を経て圧縮機２０に戻される。
【００３２】
ところで、一般に、複数台の室外機１１Ａ、１１Ｂ・・・のうち停止した室外機がある時には、この停止室外機に冷媒が滞留し、運転状態にある室外機に冷媒が不足する場合がある。
【００３３】
制御装置３５は、空気調和装置１０の冷房運転時には、室内機１２Ａ、１２Ｂ・・・の第一室内サーミスタ２７と第二室内サーミスタ２８とを用いて、室内熱交換器１８への冷媒の入口側温度と出口側温度とをそれぞれ検出し、これらの温度差が上記所定温度以上で、且つ、この時の室内膨張弁１７の弁開度が所定開度（全開状態に近い開度）以上の時に、運転状態にある室外機１１Ａ、１１Ｂ・・・に冷媒が不足していると判断する。
【００３４】
また、制御装置３５は、空気調和装置１０の暖房運転時には、運転状態にある室外機１１Ａ、１１Ｂ・・・における第二室外サーミスタ３０と第一室外サーミスタ２９とを用いて、室外熱交換器２４への冷媒の入口側温度と出口側温度とをそれぞれ検出し、これらの温度差が上記所定温度以上で、且つ、この時の室外膨張弁２５の弁開度が所定開度（全開状態に近い開度）以上である時に、当該運転状態にある室外機１１Ａ、１１Ｂ・・・に冷媒が不足していると判断する。
【００３５】
制御装置３５は、複数台の室外機１１Ａ、１１Ｂ・・・のうちに停止した室外機があり（例えば室外機１１Ａ）、それ以外の運転状態の室外機のうちの少なくとも一台（例えば室外機１１Ｂ）に冷媒が不足していることを検出したときに、冷媒が不足した室外機（例えば室外機１１Ｂ）を停止させ、または冷媒が不足した室外機（例えば室外機１１Ｂ）の運転を継続させて、停止状態にある室外機（例えば室外機１１Ａ）を運転させ、この停止室外機に滞留した冷媒を流動させる。
【００３６】
この時、各室外機１１Ａ、１１Ｂ・・・の圧縮機２０が全て容量可変型圧縮機であることから、制御装置３５は、室内機１２Ａ、１２Ｂ・・・の運転状態、例えば運転台数などに対応して各室外機１１Ａ、１１Ｂ・・・の圧縮機２０の容量を変更し、運転状態にある室外機１１Ａ、１１Ｂ・・・の能力を制御する。
【００３７】
従って、上記実施の形態によれば、次の効果▲１▼〜▲４▼を奏する。
【００３８】
▲１▼制御装置３５は、運転状態にある室外機のうち少なくとも一台（例えば室外機１１Ｂ）に冷媒が不足した時、停止状態で冷媒が滞留した室外機（例えば室外機１１Ａ）を運転させるよう制御することから、この運転を開始した室外機１１Ａに滞留する冷媒を室内機１２Ａ、１２Ｂ・・・を経て、冷媒が不足した室外機１１Ｂへ迅速に供給することができる。
【００３９】
▲２▼制御装置３５は、停止状態で冷媒が滞留した室外機（例えば室外機１１Ａ）を運転させる際に、冷媒が不足した室外機（例えば室外機１１Ｂ）を停止させることから、空気調和装置１０全体における室外機１１Ａ、１１Ｂ・・・の能力を、冷媒が滞留した室外機１１Ａの運転前の能力とほぼ等しくすることができ、室外機１１Ａ、１１Ｂ・・・全体としての過剰能力運転を防止できる。
【００４０】
▲３▼制御装置３５は、停止状態で冷媒が滞留した室外機（例えば室外機１１Ａ）を運転させる際に、冷媒が不足した室外機（例えば室外機１１Ｂ）の運転を継続させることから、全ての室外機１１Ａ、１１Ｂ・・・が運転状態となるので、空気調和装置１０の各室外機１１Ａ、１１Ｂ・・・において冷媒の偏りをなくすことができる。
【００４１】
▲４▼室外機１１Ａ、１１Ｂ・・・が備える圧縮機２０は容量制御可能な圧縮機であり、室内機１２Ａ、１２Ｂ・・・の運転状態に対応してその容量を変更することから、冷媒が不足した室外機（例えば室外機１１Ｂ）へ冷媒を供給するためにたとえ全ての室外機１１Ａ、１１Ｂ・・・を運転させた時でも、これらの室外機１１Ａ、１１Ｂ・・・の圧縮機２０の容量を、室内機１２Ａ、１２Ｂ・・・の運転状態（例えば運転台数）に対応して低下させることができるので、室外機１１Ａ、１１Ｂ・・・全体としての過剰能力運転を確実に防止できる。
【００４２】
以上、本発明を上記実施の形態に基づいて説明したが、本発明はこれに限定されるものではない。
【００４３】
【発明の効果】
以上のように、本発明に係る空気調和装置の運転方法によれば、複数台の室外機が並列に室内機に接続されると共に、夫々の室外熱交換器の温度検出並びに室外膨張弁の開度に基づく夫々の室外機の冷媒不足判断手段を備えた空気調和装置の運転方法において、運転状態にある室外機のうちの少なくとも一台に冷媒が不足した時、停止状態で冷媒が滞留した室外機を運転させるよう制御することから、冷媒が不足した室外機へ迅速に冷媒を供給することができる。
【００４４】
請求項４に記載の発明に係る空気調和装置によれば、複数台の室外機が並列に室内機に接続されると共に、夫々の室外熱交換器の温度検出並びに室外膨張弁の開度に基づく夫々の室外機の冷媒不足判断手段を備え、これらの室外機及び室内機の運転を制御装置が制御する空気調和装置において、上記制御装置は、運転状態にある室外機のうちの少なくとも一台に冷媒が不足した時、停止状態で冷媒が滞留した室外機を運転させるよう制御することから、冷媒が不足した室外機へ迅速に冷媒を供給することができる。
【図面の簡単な説明】
【図１】本発明に係る空気調和装置の一実施の形態を示す系統図である。
【図２】図１の室外機を示す冷媒回路図である。
【符号の説明】
１０空気調和装置
１１Ａ、１１Ｂ・・・室外機
１２Ａ、１２Ｂ・・・室内機
２０圧縮機
２７第一室内サーミスタ
２８第二室内サーミスタ
２９第一室外サーミスタ
３０第二室外サーミスタ
３５制御装置[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an operation method of an air conditioner including a plurality of outdoor units and an air conditioner.
[0002]
[Prior art]
In general, some air conditioners include a plurality of outdoor units each having a compressor and a plurality of indoor units connected in parallel. The compressor includes a capacity variable type compressor capable of controlling the capacity (capacity) and a constant speed type compressor capable of controlling the capacity, and each of the outdoor units is one of these types. Equipped with a compressor.
[0003]
By the way, when the air conditioner as described above is cooled or heated, if one of the outdoor units is in a stopped state, the refrigerant stays in the stopped outdoor unit, and the other outdoor unit in operation There may be a shortage of refrigerant.
[0004]
As an operation method of the air conditioner in such a case, an electromagnetic valve or the like is opened from the accumulator, receiver tank or outdoor heat exchanger of the stopped outdoor unit while keeping the outdoor unit in which the refrigerant is retained in the stopped state. Thus, the remaining refrigerant is supplied to the outdoor unit lacking the refrigerant.
[0005]
Here, the outdoor unit in which the refrigerant has accumulated is in a stopped state, for example, when the compressor of the outdoor unit is a constant speed type compressor, when the outdoor unit is operated, This is because the capacity of the outdoor unit in the entire air conditioner becomes excessive.
[0006]
[Problems to be solved by the invention]
However, when the refrigerant is supplied to the outdoor unit having a shortage of refrigerant by the operation method as described above, the outdoor unit in which the refrigerant has accumulated is in a stopped state, and thus it takes a long time to eliminate the shortage of refrigerant in the outdoor unit. Is required.
[0007]
An object of the present invention is made in consideration of the above-described circumstances, and is to provide an air conditioner that can quickly supply a refrigerant to an outdoor unit that lacks the refrigerant.
[0008]
[Means for Solving the Problems]
According to the first aspect of the present invention, a plurality of outdoor units are connected to the indoor units in parallel, and the refrigerant of each outdoor unit is insufficient based on the temperature detection of each outdoor heat exchanger and the opening of the outdoor expansion valve. In the operation method of the air conditioner provided with the judging means, the compressor included in the outdoor unit is a compressor whose capacity can be controlled, and the capacity is changed in accordance with the operating state of the indoor unit, and the operating state is changed. When at least one of the outdoor units has a shortage of refrigerant, control is performed to operate the outdoor unit in which the refrigerant has accumulated in a stopped state.
[0009]
The invention according to claim 2 is characterized in that, in the invention according to claim 1, when the outdoor unit in which the refrigerant stays in the stopped state is operated, the outdoor unit lacking the refrigerant is stopped. is there.
[0010]
The invention according to claim 3 is characterized in that, in the invention according to claim 1, when the outdoor unit in which the refrigerant stays in the stopped state is operated, the operation of the outdoor unit in which the refrigerant is insufficient is continued. Is.
[0011]
In the invention according to claim 4, a plurality of outdoor units are connected to the indoor unit in parallel, and the refrigerant of each outdoor unit based on the temperature detection of each outdoor heat exchanger and the opening of the outdoor expansion valve is insufficient. In the air conditioner including a determination unit and the control device controlling the operation of the outdoor unit and the indoor unit, the compressor included in the outdoor unit is a compressor whose capacity can be controlled, and the operation of the indoor unit is controlled by the control device. The capacity of the compressor is changed in response to a state, and the control device is configured to allow the outdoor unit in which the refrigerant stays in a stopped state when the refrigerant is insufficient in at least one of the outdoor units in an operating state. It is characterized by controlling to operate the machine.
[0012]
According to a fifth aspect of the present invention, in the invention according to the fourth aspect, the control device stops the outdoor unit lacking the refrigerant when operating the outdoor unit in which the refrigerant stays in the stopped state. It is what.
[0013]
According to a sixth aspect of the present invention, in the invention according to the fourth aspect, the control device continues the operation of the outdoor unit lacking the refrigerant when operating the outdoor unit in which the refrigerant is retained in the stopped state. It is characterized by.
[0014]
The invention according to claim 1 or 4 has the following effects.
[0015]
When the refrigerant is insufficient in at least one of the outdoor units in the operating state, control is performed to operate the outdoor unit in which the refrigerant has accumulated in the stopped state. Through the machine, it can be quickly supplied to the outdoor unit where the refrigerant is insufficient.
[0016]
In addition, the compressor included in the outdoor unit is a compressor whose capacity can be controlled, and the capacity is changed in accordance with the operation state of the indoor unit. Even when the outdoor units are operated, the capacity of the compressors of these outdoor units can be reduced corresponding to the operating state (for example, the number of operating units) of the indoor units. It can be surely prevented.
[0017]
The invention according to claim 2 or 5 has the following effects.
[0018]
When operating the outdoor unit in which the refrigerant has accumulated in the stopped state, the outdoor unit in which the refrigerant is insufficient is stopped, so the capacity of the outdoor unit in the entire air conditioner is the same as the capacity before the operation of the outdoor unit in which the refrigerant has accumulated. It can be made substantially equal, and the excess capacity operation as the whole outdoor unit can be prevented.
[0019]
The invention according to claim 3 or 6 has the following effects.
[0020]
When the outdoor unit in which the refrigerant has accumulated in the stopped state is operated, the operation of the outdoor unit in which the refrigerant is insufficient is continued, so that all the outdoor units are in the operating state. Unbiased.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0022]
FIG. 1 is a system diagram showing an embodiment of an air conditioner according to the present invention.
[0023]
In the air conditioner 10 shown in FIG. 1, a plurality of outdoor units 11A, 11B,... Are connected in parallel to a main refrigerant pipe 15 including a gas pipe 13 and a liquid pipe 14, and the main refrigerant pipe 15 is also connected. , A plurality of indoor units 12A, 12B... Are connected in parallel. The number of installed outdoor units 11A, 11B... And the indoor units 12A, 12B... Is set according to the amount of air conditioning load, for example, the size of the building in which the air conditioner 10 is equipped.
[0024]
The indoor units 12A, 12B,... Are configured by arranging an indoor expansion valve 17 and an indoor heat exchanger 18 in an indoor refrigerant pipe 16, with one end of the indoor refrigerant pipe 16 being a gas pipe 13 and the other being a liquid. Each is connected to a tube 14.
[0025]
The indoor refrigerant pipe 16 is provided with a first indoor thermistor 27 and a second indoor thermistor 28 before and after the indoor heat exchanger 18, respectively, and the refrigerant temperature detected by these is sent to the control device 35 shown in FIG. Sent. The controller 35 controls the indoor expansion valve 17 so that the temperature difference between the refrigerant detected by the first indoor thermistor 27 and the second indoor thermistor 28 becomes a predetermined temperature during the cooling or heating operation of the air conditioner 10. To control the air conditioning load.
[0026]
As shown in FIG. 2, the outdoor units 11A, 11B,... Have a compressor 20 disposed in the outdoor refrigerant pipe 19, an accumulator 21 disposed on the suction side of the compressor 20, and oil on the discharge side. The separator 22 and the four-way valve 23 are sequentially arranged, and the outdoor heat exchanger 24, the outdoor expansion valve 25, and the receiver tank 38 are sequentially arranged in the outdoor refrigerant pipe 19 on the oil separator 22 side. The end of the outdoor refrigerant pipe 19 on the receiver tank 38 side is connected to the liquid pipe 14 of the main refrigerant pipe 15. The end of the outdoor refrigerant pipe 19 on the accumulator 21 side is connected to the gas pipe 13 of the main refrigerant pipe 15 via a four-way valve 23.
[0027]
In the outdoor refrigerant pipe 19, a first outdoor thermistor 29 and a second outdoor thermistor 30 are respectively installed before and after the outdoor heat exchanger 24, and the refrigerant temperature detected by these is transmitted to the control device 35. The control device 35 controls the outdoor expansion valve 25 so that the temperature difference between the refrigerant detected by the first outdoor thermistor 29 and the second outdoor thermistor 30 becomes a predetermined temperature especially during the heating operation of the air conditioner 10. Control valve opening to cope with air conditioning load.
[0028]
The compressors 20 of the outdoor units 11A, 11B,... Are internal high-pressure compressors, and are variable capacity compressors capable of capacity (capacity) control. The operation, stop, or capacity control of the compressor 20 is performed by the control device 35 in accordance with the operation status such as the number of the indoor units 12A, 12B,.
The oil separator 22 separates refrigeration oil in the gas refrigerant discharged from the compressor 20, and returns the oil to a pipe line (suction pipe line) from the accumulator 21 to the compressor 20 in the outdoor refrigerant pipe 19. It is connected via a pipe 26. Accordingly, the refrigerating machine oil separated by the oil separator 22 is appropriately returned to the suction pipe line in the outdoor refrigerant pipe 19, that is, the compressor 20 through the oil return pipe 26.
[0029]
The four-way valve 23 is switched by the control device 35, and the air conditioner 10 is set to the cooling operation or the heating operation by this switching.
[0030]
That is, when the four-way valve 23 is switched to the cooling side, the refrigerant flows as indicated by a solid arrow A, and the refrigerant discharged from the compressors 20 of the outdoor units 11A, 11B,. To the outdoor heat exchanger 24, condensed in the outdoor heat exchanger 24, merged in the liquid pipe 14 through the outdoor expansion valve 25 and the receiver tank 38, and divided into the indoor units 12A, 12B,. After the pressure is reduced through the indoor expansion valves 17 of these indoor units 12A, 12B,..., They are evaporated by the indoor heat exchanger 18 to cool the room. The refrigerant from the indoor heat exchanger 18 of each of the indoor units 12A, 12B,... Is merged in the gas pipe 13 and is divided into the outdoor units 11A, 11B,. The four-way valve 23 and the accumulator 21 are returned to the compressor 20.
[0031]
Further, when the four-way valve 23 is switched to the heating side, the refrigerant flows as indicated by the broken line arrow B, and the refrigerant discharged from the compressors 20 of the outdoor units 11A, 11B,. The gas pipes 13 are joined together, the indoor units 12A, 12B,... Are shunted, and the indoor heat exchanger 18 of each of the indoor units 12A, 12B,. The refrigerant condensed in the indoor heat exchanger 18 is depressurized by the indoor expansion valve 17, merged by the liquid pipe 14, and divided by the outdoor units 11 </ b> A, 11 </ b> B... The pressure is reduced again by the outdoor expansion valve 25 through the receiver tank 38 of 11B... And evaporated by the outdoor heat exchanger 24, and then returned to the compressor 20 through the four-way valve 23 and the accumulator 21.
[0032]
By the way, generally, when there is a stopped outdoor unit among the plurality of outdoor units 11A, 11B,..., Refrigerant may stay in the stopped outdoor unit, and the outdoor unit in an operating state may run out of refrigerant.
[0033]
During the cooling operation of the air conditioner 10, the control device 35 uses the first indoor thermistor 27 and the second indoor thermistor 28 of the indoor units 12A, 12B. The temperature and the outlet side temperature are detected, respectively, and when the temperature difference is equal to or higher than the predetermined temperature and the opening of the indoor expansion valve 17 at this time is equal to or higher than a predetermined opening (opening close to a fully opened state). It is determined that the outdoor units 11A, 11B,.
[0034]
Further, the control device 35 uses the second outdoor thermistor 30 and the first outdoor thermistor 29 in the outdoor units 11A, 11B... In the operating state during the heating operation of the air conditioner 10, and uses the outdoor heat exchanger 24. The refrigerant inlet side temperature and the outlet side temperature are respectively detected, the temperature difference between them is equal to or higher than the predetermined temperature, and the valve opening degree of the outdoor expansion valve 25 at this time is a predetermined opening degree (close to a fully opened state). When it is equal to or greater than (opening degree), it is determined that the outdoor units 11A, 11B,.
[0035]
The control device 35 includes a stopped outdoor unit (for example, the outdoor unit 11A) among the plurality of outdoor units 11A, 11B,..., And at least one of the other outdoor units (for example, the outdoor unit). 11B), when it is detected that the refrigerant is insufficient, the outdoor unit (for example, the outdoor unit 11B) in which the refrigerant is insufficient is stopped, or the operation of the outdoor unit (for example, the outdoor unit 11B) in which the refrigerant is insufficient is continued. Then, the outdoor unit in a stopped state (for example, the outdoor unit 11A) is operated, and the refrigerant accumulated in the stopped outdoor unit is caused to flow.
[0036]
At this time, since the compressors 20 of the outdoor units 11A, 11B,... Are all variable capacity compressors, the control device 35 determines the operating state of the indoor units 12A, 12B,. Correspondingly, the capacity of the compressors 20 of the outdoor units 11A, 11B,... Is changed to control the capacity of the outdoor units 11A, 11B,.
[0037]
Therefore, according to the above embodiment, the following effects (1) to (4) are obtained.
[0038]
(1) When at least one of the outdoor units in the operating state (for example, the outdoor unit 11B) has a shortage of refrigerant, the control device 35 operates the outdoor unit (for example, the outdoor unit 11A) in which the refrigerant has accumulated in the stopped state. Thus, the refrigerant that stays in the outdoor unit 11A that has started this operation can be quickly supplied to the outdoor unit 11B that lacks the refrigerant through the indoor units 12A, 12B,.
[0039]
(2) The control device 35 stops the outdoor unit (for example, the outdoor unit 11B) lacking the refrigerant when operating the outdoor unit (for example, the outdoor unit 11A) in which the refrigerant has accumulated in the stopped state. The capacity of the outdoor units 11A, 11B... In the entire unit 10 can be made substantially equal to the capacity of the outdoor unit 11A in which refrigerant has accumulated before the operation, and the capacity of the outdoor units 11A, 11B. Can be prevented.
[0040]
(3) Since the control device 35 continues the operation of the outdoor unit (for example, the outdoor unit 11B) lacking the refrigerant when operating the outdoor unit (for example, the outdoor unit 11A) in which the refrigerant has accumulated in the stopped state, Since the outdoor units 11A, 11B, etc. are in an operating state, the refrigerant in the outdoor units 11A, 11B,.
[0041]
(4) The compressor 20 included in the outdoor units 11A, 11B... Is a compressor whose capacity can be controlled, and the capacity is changed in accordance with the operating state of the indoor units 12A, 12B. Even when all the outdoor units 11A, 11B,... Are operated to supply the refrigerant to an outdoor unit (for example, the outdoor unit 11B) that lacks the compressor, the compressors 20 of these outdoor units 11A, 11B,. Can be reduced corresponding to the operating state (for example, the number of operating units) of the indoor units 12A, 12B,..., So that the excess capacity operation of the outdoor units 11A, 11B,. .
[0042]
As mentioned above, although this invention was demonstrated based on the said embodiment, this invention is not limited to this.
[0043]
【The invention's effect】
As described above, according to the operation method of the air conditioner according to the present invention, a plurality of outdoor units are connected to the indoor unit in parallel, the temperature of each outdoor heat exchanger is detected, and the outdoor expansion valve is opened. In the operation method of the air conditioner provided with the refrigerant shortage determination means of each outdoor unit based on the degree, when the refrigerant is insufficient in at least one of the outdoor units in the operating state, the outdoor in which the refrigerant has accumulated in the stopped state Since the control is performed so that the machine is operated, the refrigerant can be quickly supplied to the outdoor unit in which the refrigerant is insufficient.
[0044]
According to the air conditioner pertaining to the fourth aspect of the present invention, a plurality of outdoor units are connected to the indoor unit in parallel, based on the temperature detection of each outdoor heat exchanger and the opening of the outdoor expansion valve. In an air conditioner that includes a refrigerant shortage determination unit for each outdoor unit, and the control device controls the operation of the outdoor unit and the indoor unit, the control device is provided in at least one of the outdoor units in the operating state. When the refrigerant runs short, control is performed so that the outdoor unit in which the refrigerant stays in a stopped state is operated, so that the refrigerant can be quickly supplied to the outdoor unit lacking the refrigerant.
[Brief description of the drawings]
FIG. 1 is a system diagram showing an embodiment of an air conditioner according to the present invention.
FIG. 2 is a refrigerant circuit diagram showing the outdoor unit of FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Air conditioning apparatus 11A, 11B ... Outdoor unit 12A, 12B ... Indoor unit 20 Compressor 27 First indoor thermistor 28 Second indoor thermistor 29 First outdoor thermistor 30 Second outdoor thermistor 35 Control device

Claims

A plurality of outdoor units are connected to an indoor unit in parallel, and the air conditioner includes a refrigerant shortage determination unit for each outdoor unit based on the temperature detection of each outdoor heat exchanger and the opening of the outdoor expansion valve . In the operation method, the compressor included in the outdoor unit is a compressor whose capacity can be controlled, the capacity of the compressor is changed according to the operation state of the indoor unit, and at least one of the outdoor units in the operation state. An operation method of an air conditioner, characterized in that, when the refrigerant runs short in the stand, the outdoor unit in which the refrigerant has accumulated in a stopped state is controlled to operate.

The operation method of the air conditioner according to claim 1, wherein when operating the outdoor unit in which the refrigerant stays in a stopped state, the outdoor unit in which the refrigerant is insufficient is stopped.

2. The method of operating an air conditioner according to claim 1, wherein when the outdoor unit in which the refrigerant has accumulated in a stopped state is operated, the operation of the outdoor unit in which the refrigerant is insufficient is continued.

A plurality of outdoor units are connected to the indoor units in parallel, and are provided with refrigerant shortage determining means for each outdoor unit based on the temperature detection of each outdoor heat exchanger and the opening of the outdoor expansion valve. And the air conditioner in which the controller controls the operation of the indoor unit, the compressor included in the outdoor unit is a compressor whose capacity can be controlled, and the controller controls the compressor according to the operating state of the indoor unit. When the capacity is changed, the control device controls to operate the outdoor unit in which the refrigerant stays in the stopped state when the refrigerant is insufficient in at least one of the outdoor units in the operating state. An air conditioner characterized.

The air conditioner according to claim 4, wherein the control device stops the outdoor unit lacking the refrigerant when operating the outdoor unit in which the refrigerant stays in the stopped state.

The air conditioner according to claim 4, wherein the control device continues the operation of the outdoor unit in which the refrigerant is insufficient when operating the outdoor unit in which the refrigerant is retained in the stopped state.