JP3834905B2

JP3834905B2 - Multi-room air conditioner

Info

Publication number: JP3834905B2
Application number: JP00936597A
Authority: JP
Inventors: 和生中谷; 正夫蔵地; 一彦丸本; 孝金子; 道美日下
Original assignee: Panasonic Corp; Matsushita Electric Industrial Co Ltd
Current assignee: Panasonic Corp; Panasonic Holdings Corp
Priority date: 1997-01-22
Filing date: 1997-01-22
Publication date: 2006-10-18
Anticipated expiration: 2017-01-22
Also published as: JPH10205853A

Abstract

PROBLEM TO BE SOLVED: To provide a multi-chamber type air conditioner in which capacity can be controlled so as to meet load regardless of high or low load by a simple constitution and control and a highly efficient operation having no excessive deficiency in capacity can be done within a wide load range. SOLUTION: According to the provision of start and stop control means 37 of a plurality of compressors, when the total load of indoor machines 29a, 29b, 29c, and 29d is larger than the set value of a high load side, a constant rate compressor 20 with small capacity is started or stopped and a constant rate compressor 21 with large capacity is continuously operated. When the total load is located between the set value of the high load side and the set value of a low load side, the constant rate compressor 20 with small capacity and the constant rate compressor 21 with large capacity are alternately started and stopped. Further, a controller 37 for starting/stopping compressor is provided, and when the total load is smaller than the set value of the low load side, the constant rate compressor 20 with small capacity is stated or stopped and the constant rate compressor 21 with large capacity is stopped.

Description

【０００１】
【発明の属する技術分野】
本発明は、複数台の圧縮機を搭載した多室型空気調和機に関するものであり、詳しくはその室外ユニットの能力制御に関するものである。
【０００２】
【従来の技術】
図７は、特開昭６３−２９５８８０号公報に記載された従来の多室型空気調和機のシステム構成図であり、１は能力の小さい極数変換可能な第１圧縮機であり、能力は４ＨＰと２ＨＰの制御が可能である。２は能力の大きい極数変換可能な第２圧縮機であり、能力は６ＨＰと３ＨＰの制御が可能である。
【０００３】
３ａ，３ｂは第１圧縮機１または第２圧縮機２の内、片方が運転し他方が停止していた場合に、停止側の圧縮機への冷媒寝込み防止用逆止弁、４は室外側熱交換器、５はアキュムレータ６は第１圧縮機１と第２圧縮機２内の冷凍機油のレベルを同一にする均油管であり、これらは室外ユニット７に収納されている。８ａ，８ｂ，８ｃ，８ｄはユニットで、それぞれ全閉機能を備えた室内側減圧装置９ａ，９ｂ，９ｃ，９ｄと室内側熱交換器１０ａ，１０ｂ，１０ｃ，１０ｄを有している。
【０００４】
ここで室内ユニット８ａ，８ｃは能力が３ＨＰであり、室内ユニット８ｂ，８ｄは能力が２ＨＰである。
また、この室内ユニット８ａ，８ｂ，８ｃ，８ｄと室外ユニット７はガス側主配管１１と液側主配管１２およびガス側主配管１１より分岐したガス側支管１１ａ，１１ｂ，１１ｃ，１１ｄと液側支管１２ａ，１２ｂ，１２ｃ，１２ｄによって連通されている。
【０００５】
次に従来の多室型空気調和機について、以下動作を説明する。
第１圧縮機１および第２圧縮機より吐出された冷媒は逆止弁３ａ，３ｂを通って室外側熱交換器４に送られ凝縮液化し、液側主配管１２、液側支管１２ａ，１２ｂ，１２ｃ，１２ｄを通って室内ユニット８ａ，８ｂ，８ｃ，８ｄに送られる。ここで室内側減圧装置９ａ，９ｂ，９ｃ，９ｄで減圧され、室内側熱交換器１０ａ，１０ｂ，１０ｃ，１０ｄで蒸発し、冷房に寄与してガス化され、ガス側支管１１ａ，１１ｂ，１１ｃ，１１ｄ、およびガス側主配管１１を通って室外ユニット７に送られ、アキュムレータ５から第１圧縮機１および第２圧縮機に帰還し循環する。
【０００６】
ここで、たとえば室内ユニット８ａ，８ｂ，８ｃ，８ｄが４台運転中、３ＨＰの容量である室内ユニット８ａが運転を停止した場合には、室内運転容量は７０％となり、６ＨＰの能力を持つ第２圧縮機２の極数を２極から４極として第２圧縮機２の能力を半減することにより、室外ユニット７の能力は７ＨＰ（７０％）となり、室内運転容量に見合った室外ユニット能力を出力することができる。
【０００７】
この従来の多室型空気調和機によれば、それぞれ２極４極変換可能な第１圧縮機１と第２圧縮機２の能力比を２対３（２極時４ＨＰ対６ＨＰ、４極時２ＨＰ対３ＨＰ）にすることにより、能力が８段階に制御可能となり、複数の異馬力室内ユニットを個別に運転し、運転容量が変化しても室外ユニットの能力を室内ユニットの運転容量に簡単に合わすことができるので、システム構成が簡素化され効率のよい運転が実現できるものである。
【０００８】
【発明が解決しようとする課題】
しかしながら、このような従来の多室型空気調和機では、極変圧縮機を用いた段階制御となっているため、圧縮機の運転台数の変更と共に、極数の変更を行う必要があり、切り換えの回数が増加して制御が複雑になっていた。
【０００９】
また、第１圧縮機１と第２圧縮機２の能力比を２対３とし、かつそれぞれの圧縮機を２極４極変換可能として、それぞれを組み合わせる運転をすることにより能力の段階制御（２ＨＰ〜１０ＨＰすなわち２０％，３０％，４０％，・・・，１００％運転）を可能とするものであるが、これらの段階の中間の能力が必要な場合、たとえば３．５ＨＰの室内ユニットを運転する場合には３５％の能力制御が必要となるが、ここにおいては１０％ごとの段階制御であるため、第１圧縮機１を停止し、第２圧縮機２を４極で運転する３ＨＰ（３０％）運転では、３．５ＨＰの室外ユニットの能力を満たすことができず能力不足となり、また第１圧縮機１を２極で運転し、第２圧縮機２を停止する４ＨＰ（４０％）運転では、能力が過剰となるため減圧装置で過度に減圧して能力低下させる必要があり、運転効率が低下する問題点があった。
【００１０】
本発明は従来の課題を解決するものであり、簡単な構成および制御によって、負荷の大小にかかわらず負荷に見合った能力制御が可能となり、広い負荷範囲で能力の過不足の起こることのない高効率な運転のできる多室型空気調和機を提供するものである。
【００１１】
【課題を解決するための手段】
この目的を達成するため本発明は、大容量一定速圧縮機と小容量一定速圧縮機を備え、室内機の総負荷と大容量一定速圧縮機の能力に相当する高負荷側設定値、小容量一定速圧縮機の能力に相当する低負荷側設定値を比較し、その比較結果に応じて大容量および小容量一定速圧縮機の運転／停止をさせることにより、あらゆる負荷の状況でも、簡単な制御で広範囲の能力制御が可能となり、高効率な運転が可能となる。
【００１２】
また、総負荷が低負荷側設定値より小さく、総負荷と低負荷側設定値との差が大きい場合には、吐出系統と吸入系統を接続するバイパス弁を開方向に動作させることにより、吐出ガスの吸入系統へのバイパス量を調整することにより、負荷が小さい場合にもきめ細かい能力制御が可能となる。さらにまた、総負荷と設定値との差に応じてバイパス量を調整することにより広範囲での能力制御を可能とし、また、バイパス量の過剰な場合には圧縮機台数制御に切り換えるようにしたので、バイパス量増加による効率の低下を防止しながら、高効率な運転を行うことができる。
【００１３】
【発明の実施の形態】
本発明は、大容量一定速圧縮機、小容量一定速圧縮機、四方弁、室外側熱交換器、室外側絞り装置からなる室外機と、室内側交換器、室内側絞り装置からなる複数の室内機を接続して冷媒回路を構成し、前記大容量一定速圧縮機の運転能力に略相当する負荷を高負荷側設定値とし、前記小容量一定速圧縮機の運転能力に略相当する負荷を低負荷側設定値とし、前記複数の室内機の総負荷を検知する総負荷検知手段と、前記総負荷と前記高負荷側設定値と前記低負荷側設定値を比較する負荷比較手段と、前記負荷比較手段により比較された結果に基づき前記総負荷が、前記高負荷側設定値より大きい場合は、前記小容量一定速圧縮機が発停し、かつ前記大容量一定速圧縮機が連続運転し、また、前記総負荷が前記高負荷側設定値と前記低負荷側設定値の中間の場合は、前記小容量一定速圧縮機と前記大容量一定速圧縮機が交互に発停し、また、前記総負荷が停負荷側設定値より小さい場合は、前記大容量一定速圧縮機が停止し、前記小容量一定速圧縮機が発停する複数圧縮機発停制御手段を設けるものである。
【００１４】
また、前記大容量一定速圧縮機および前記小容量一定速圧縮機の吐出系統と吸入系統を接続するバイパス弁を有するバイパス管を設け、総負荷が低負荷側設定値より小さい場合に小容量一定速圧縮機が連続運転し、かつ大容量一定速圧縮機が停止し、前記総負荷と低負荷側設定値との差に応じて前記バイパス弁を開閉するシステム能力制御手段を設けるものである。
【００１５】
また、前記総負荷が高負荷側設定値より大きい場合は小容量一定速圧縮機および大容量一定速圧縮機圧縮機が連続運転し、かつ総負荷と高負荷側設定値との差に応じて前記バイパス弁を開閉し、また前記総負荷が高負荷側設定値と低負荷側設定値の間の場合には、小容量一定速圧縮機は停止し、大容量一定速圧縮機が連続運転し、かつ総負荷と高負荷側設定値との差に応じて前記バイパス弁を開閉し、また前記総負荷が低負荷側設定値より小さい場合は小容量一定速圧縮機が連続運転し、大容量一定速圧縮機は停止し、かつ総負荷と高負荷側設定値との差に応じて前記バイパス弁を開閉するシステム能力手段を設けるものである。
【００１６】
また、前記総負荷が高負荷側設定値より大きい場合は小容量一定速圧縮機および大容量一定速圧縮機が連続運転し、かつ総負荷と高負荷側設定値との差に応じて前記バイパス弁を開閉し、総負荷と高負荷側設定値との差が所定値以上になった場合には、バイパス弁を閉止し、小容量一定速圧縮機が発停かつ大容量一定速圧縮機が連続運転し、また前記総負荷が高負荷側設定値と低負荷側設定値の間の場合には、小容量一定速圧縮機は停止し、大容量一定速圧縮機が連続運転し、かつ総負荷と高負荷側設定値との差に応じて前記バイパス弁を開閉し、総負荷と高負荷側設定値との差が所定値以上になった場合には、バイパス弁を閉止し、小容量一定速圧縮機と大容量一定速圧縮機が交互に発停し、さらに、前記総負荷が低負荷側設定値より小さい場合は小容量一定速圧縮機が連続運転し、かつ大容量一定速圧縮機は停止し、かつ総負荷と高負荷側設定値との差に応じて前記バイパス弁を開閉するシステム能力制御手段を設けるものである。
【００１７】
また、総負荷が低負荷側設定値より小さい場合は、大容量一定速圧縮機が停止し、小容量一定速圧縮機が連続運転し、かつ総負荷と低負荷側設定値との差に応じてバイパス弁を開閉動作し、かつ総負荷が所定値よりも小さい場合は、大容量一定速圧縮機が停止し、小容量一定速圧縮機が発停するシステム能力制御手段を設けたものである。
【００１８】
また、総負荷が高負荷側設定値と低負荷側設定値の中間の場合で、小容量一定速圧縮機と大容量一定速圧縮機が交互に発停するときは、小容量一定速圧縮機の運転開始と大容量一定速圧縮機の運転停止とが略同時であり、また小容量一定速圧縮機の運転停止と大容量一定速圧縮機の運転開始とが略同時であるようにするものである。
【００１９】
また、総負荷が高負荷側設定値と停負荷側設定値の中間の場合で、小容量一定速圧縮機と大容量一定速圧縮機が交互に発停するときは、総負荷に応じて小容量一定速圧縮機の運転時間と大容量一定速圧縮機の運転時間の比率を制御するものである。
【００２０】
本発明は上記のような構成をもつことにより、室内機の総負荷を検出し、あらかじめ設定してある高負荷設定値と停負荷設定値と総負荷とを比較して、総負荷が高負荷側設定値より大きい場合は、大容量一定速圧縮機を連続運転させ、かつ小容量一定速圧縮機は総負荷の大小により運転または停止を制御することにより、比較的大きな負荷の場合にそれに見合った能力の運転が可能となる。また、前記総負荷が高負荷側設定値と低負荷側設定値の間の場合には、小容量一定速圧縮機と大容量一定速圧縮機を交互に発停させ、各圧縮機の発停を制御することにより中程度の負荷の場合に、それに見合った能力の運転が可能となる。また、総負荷が停負荷側設定値より小さい場合には、大容量一定速圧縮機は停止させ、小容量一定速圧縮機は総負荷の大小により運転または停止を制御することにより比較的小さな負荷の場合にそれに見合った能力の運転が可能となり、圧縮機の簡単な運転台数制御で広範囲の負荷状況において連続した能力制御が可能となり、能力の過不足は起こることなく、常に高効率な運転が可能となる。また、吐出系統と吸入系統を接続するバイパス弁を有するバイパス管を設け、総負荷と低負荷側設定値との差が大きい場合には前記バイパス弁を開方向に動作させることにより、総負荷が低負荷側設定値より小さい場合に、大容量一定速圧縮機を停止、小容量一定速圧縮機を連続運転させ、吐出ガスの吸入系統へのバイパス量を調整することにより、冷凍サイクルの冷媒循環量を減少させて、負荷が小さい場合にもきめ細かい能力制御が可能となる。
【００２１】
また、総負荷が高負荷側設定値より大きい場合は小容量一定速圧縮機および大容量一定速圧縮機を連続運転さら、また、総負荷と高負荷側設定値との差が大きい場合には前記バイパスを開方向に動作させ、吐出ガスの吸入系統へのバイパス量を調整することにより、冷凍サイクルの冷媒循環量を減少させてきめ細かい能力制御を可能とし、差が一定値以上になった場合には小容量一定速圧縮機を発停させ、大容量一定速圧縮機を連続運転させることにより、大きな負荷変動に対しても追従できる能力制御が可能となる。また、総負荷が所定値よりも小さい場合は、大容量一定速圧縮機が停止し、小容量一定速圧縮機が発停するシステム能力制御手段を設けることにより、バイパスでは制御できなかいような小さい負荷においても、確実に能力制御でき、また、バイパス量の増加に伴う効率の低下も起こることがない。
【００２２】
また、小容量一定速圧縮機と大容量一定速圧縮機の交互運転の場合、小容量一定速圧縮機の運転／停止と大容量一定速圧縮機の停止／運転とを略同時にすることにより、圧縮機の切換時に大きく圧力変動などを起こすことがなく、したがって、起動停止にともなう能力や入力のロスがなくなるものである。
【００２３】
また、総負荷が高負荷側設定値と停負荷側設定値の中間の場合は、小容量一定速圧縮機と大容量一定速圧縮機が交互に発停し、かつ総負荷に応じて小容量一定速圧縮機の運転時間と大容量一定速圧縮機の運転時間の比率を制御することにより、略小容量一定速圧縮機から大容量一定速圧縮機の能力相当の負荷に対して、連続的でしかもきめ細かい能力制御が可能となる。
【００２４】
【実施例】
以下、本発明による多室型空気調和機の一実施例を図に基づいて説明する。
【００２５】
（実施例１）
図１は本発明の実施例１による多室型空気調和機のシステム構成図であり、２０は能力の小さい小容量一定速圧縮機であり、能力は４ＨＰである。２１は能力の大きい大容量一定速圧縮機であり、能力は６ＨＰである。
【００２６】
２２ａ，２２ｂは小容量一定速圧縮機２０または大容量一定速圧縮機２１の内、片方が運転し他方が停止していた場合に、停止側の圧縮機への冷媒寝込み防止用逆止弁、２３は四方弁、２４は室外側熱交換器、２５はアキュムレータ、２６は小容量一定速圧縮機２０と大容量一定速圧縮機２１内の冷凍機油のレベルを同一にする均油管、２７は室外側膨脹弁（室外側絞り装置）であり、これらは室外ユニット（室外機）２８に収納されている。
【００２７】
２９ａ，２９ｂ，２９ｃ，２９ｄは室内側ユニット（室内機）で、それぞれ全閉機能を備えた室内側膨脹弁（室内側絞り装置）３０ａ，３０ｂ，３０ｃ，３０ｄと室内側熱交換器３１ａ，３１ｂ，３１ｃ，３１ｄを有している。また、この室内ユニット２９ａ，２９ｂ，２９ｃ，２９ｄと室外ユニット２８はガス側主配管３２と液側主配管３３およびガス側主配管３２より分岐したガス支管３２ａ，３２ｂ，３２ｃ，３２ｄと液側支管３３ａ，３３ｂ，３３ｃ，３３ｄによって連通されている。
【００２８】
また、３４ａ，３４ｂ，３４ｃ，３４ｄは各室内ユニット２９ａ，２９ｂ，２９ｃ，２９ｄの室温を計測する室温センサーであり、その出力は総負荷検知手段３５に送られる。ここでは、運転中の室内ユニットの総負荷を検知し算出することができる。また、３６は総負荷検知手段３５で計算された総負荷と、あらかじめ設定してある高負荷側設定値および低負荷側設定値とを比較する負荷比較手段である。そして、３７は負荷比較手段３６の比較結果に基づき、小容量一定速圧縮機２０および大容量一定速圧縮機２１の運転、停止を制御する複数圧縮機発停制御手段である。
【００２９】
次にこの多室型空気調和機について、ここでは冷房運転時を例に動作を説明する。
【００３０】
小容量一定速圧縮機２０および大容量一定速圧縮機２１より吐出された冷媒は逆止弁２２ａ，２２ｂ、逆止弁２３を通って室外側熱交換器２４に送られ凝縮液化し、室外側膨脹弁２７および液側主配管３３、液側支管３３ａ，３３ｂ，３３ｃ，３３ｄを通って室内ユニット２９ａ，２９ｂ，２９ｃ，２９ｄに送られる。さらに室内側膨脹弁３０ａ，３０ｂ，３０ｃ，３０ｄで減圧され、室内側熱交換器３１ａ、３１ｂ、３１ｃ、３１ｄで蒸発し、冷房に寄与してガス化され、ガス側支管３２ａ，３２ｂ，３２ｃ，３２ｄ、およびガス側主配管３２を通って室外ユニット２８に送られ、四方弁２３、アキュムレータ２５を通り、小容量一定速圧縮機２０および大容量一定速圧縮機２１に帰還し循環する。
【００３１】
一方、各室内ユニット２９ａ，２９ｂ，２９ｃ，２９ｄの室温が室温センサー３４ａ，３４ｂ，３４ｃ，３４ｄで計測され、各室温の値は総負荷を検知する総負荷検知手段２５に送られる。ここでは、あらかじめ設定してある各室内ユニットの目標設定温度と室温との差および運転中の室内ユニットの容量（ＨＰ数）から式（１）の演算を行い、総負荷を算出する。
【００３２】
総負荷＝Σ運転室内機のＨＰ数×（室温−目標設定温度）式（１）
さらに、大容量一定速圧縮機２１の運転能力に相当する負荷（６ＨＰ相当）を高負荷側設定値とし、小容量一定速圧縮機２０の運転能力に相当する負荷（４ＨＰ相当）を低負荷側設定値として定める。そして総負荷検知手段３５で計算された総負荷と、設定した高負荷側設定値および低負荷側設定値との比較結果に基づき、小容量一定速圧縮機２０および大容量一定速圧縮機２１の運転、停止を制御する。これを図２に示す運転制御フローチャートで説明する。
【００３３】
総負荷検知手段３５で検知された総負荷と高負荷側設定値との大小を判定し（４０）、大の場合は大容量一定速圧縮機２１（６ＨＰ）を連続運転させ小容量一定速圧縮機２０（４ＨＰ）は総負荷の値の大小や適正な圧力範囲になるように運転／停止を制御する（４１）。こうすることにより、６ＨＰ〜１０ＨＰの範囲の負荷に対応できる制御となる。
【００３４】
また、総負荷が高負荷側設定値より小の場合は、総負荷と低負荷側設定値と大小を判定し（４２）、大の場合には大容量一定速圧縮機２１と小容量一定速圧縮機２０を、総負荷の値の大小や適正な圧力範囲になるように交互に運転させることにより、４ＨＰ〜６ＨＰの範囲の負荷に対応した制御が可能となる（４３）。
【００３５】
すなわち、ここでは小容量一定速圧縮機２０と大容量一定速圧縮機２１の運転時間の比率を制御することにより、４ＨＰ〜６ＨＰの連続したきめ細かい能力制御が可能となるものである。
【００３６】
さらに、総負荷が低負荷側設定値より小の場合には大容量一定速圧縮機２１を停止し、小容量一定速圧縮機２０を、総負荷の値の大小や適正な圧力範囲になるように運転／停止を制御することにより、０ＨＰ〜４ＨＰの範囲の負荷に対応した能力制御か可能となる（４４）。
【００３７】
一方、小容量一定速圧縮機２０と大容量一定速圧縮機２１の交互運転の場合、小容量一定速圧縮機２０の運転開始時と大容量一定速圧縮機２１の運転停止時とほぼ同時にすれば、圧縮機の切換時の大きな圧力変動を起こすことがないため、冷凍サイクルの圧力がほぼ保たれるので、小容量一定速圧縮機２０の起動によって引き起こされる能力や入力のロスがなくなるものである。
【００３８】
以上のように、容量の異なる２台の一定速圧縮機の簡単な運転台数制御により、広い範囲での負荷に対応した（ここでは０ＨＰ〜１０ＨＰ）運転が可能となり、能力の過不足が起こることなく常に高効率なサイクルで運転できるものである。特に、本実施例では４ＨＰ〜６ＨＰの範囲においては、小容量一定速圧縮機２０と大容量一定速圧縮機２１を負荷に応じて交互に運転することにより、ほぼ連続したきめ細かい能力制御が可能であり、負荷変動に常に対応した高効率な運転が実現できるものである。
【００３９】
なお、本実施例では小容量一定速圧縮機２０を４ＨＰ、大容量一定速圧縮機２１を６ＨＰとして説明したが、これにこだわるものではなく、どのような容量の組み合わせも本発明に含まれるものである。
【００４０】
さらに、本実施例では総負荷検知手段３５での総負荷を式（１）で示すものとして説明したが、運転機のＨＰ数のみとして算出する負荷や外気温と室内との差などから算出できる負荷などとしても同様であり、これらは本発明に含まれるものである。
【００４１】
（実施例２）
図３は本発明の実施例２の多室型空気調和機のシステム構成図であり、図１と同様の構成で同様の機能を有するものについては同一の番号を記してあり、説明は省略する。
【００４２】
ここでは、逆止弁２２ａ，２２ｂと四方弁２３の間の吐出管５０とアキュムレータ２５と四方弁２３の間の吸入管５１をバイパス弁５２を介して接続している。また、負荷比較手段３６の比較結果に基づき、小容量一定速圧縮機２０および大容量一定速圧縮機２１の運転、停止を制御すると共にバイパス弁５２の開度を制御するシステム能力制御手段５３を設けている。
【００４３】
ここでは、総負荷検知手段３５で計算された総負荷と、あらかじめ設定してある高負荷側設定値および低負荷側設定値との比較結果に基づき、小容量一定速圧縮機２０および大容量一定速圧縮機２１の運転、停止およびバイパス弁５２の開度を制御するが、これを図４に示す運転制御フローチャートで説明する。ここにおいても図２と同様のフローを示すものについては同様の番号を記してあり、説明は省略する。
【００４４】
総負荷検知手段３５で検知された総負荷が高負荷側設定値より小の場合は、総負荷と低負荷側設定値との大小を判定し（４２）、総負荷が低負荷側設定値より小の場合には大容量一定速圧縮機２１を停止し、小容量一定速圧縮機２０を連続運転させる（５３）。さらに、総負荷の値の大小を判定し（５４）、総負荷が増加する場合にはバイパス弁５２を開方向に動作させ（５５）、総負荷が減少する場合にはバイパス弁５２を開方向に動作させる（５６）。こうすることにより、負荷が減少してきた場合には、小容量一定速圧縮機２０の吐出ガスを吐出管５０からバイパス弁５２を介して吸入管５１へとバイパスさせて冷凍サイクルへの冷媒循環量を下げて能力を減少させることができる。
【００４５】
すなわち、総負荷が低負荷側設定値より小さい場合には、小容量一定速圧縮機の運転／停止ではなく、バイパス弁５２の開度制御による連続した、きめ細かい能力制御ができるので、圧縮機の運転／停止にともなう大きな能力変動が起こることなく安定した運転ができる。
【００４６】
一方、総負荷の値の大小を判定して（５４）、それが所定値よりも小さい場合は、大容量一定速圧縮機を停止し、小容量一定速圧縮機のみで総負荷の値の大小や適正な圧力範囲になるように発停するようにすれば、バイパスでは制御できないような小さい負荷においても、確実に能力制御でき、また、バイパス量の増加に伴う効率の低下も起こることがない。
【００４７】
（実施例３）
図５は本発明の実施例３による多室型空気調和機の運転制御フローチャートを示す。また、ここで示すシステム構成図は図３と同様であり、説明は省略し、各圧縮機の制御およびバイパス弁５２の制御について説明する。
【００４８】
総負荷検知手段３５で検知された総負荷と高負荷側設定値と大小を判定し（６０）、大の場合は大容量一定速圧縮機２１（６ＨＰ）および小容量一定速圧縮機２０（４ＨＰ）を連続運転させる（６１）。さらに、総負荷の値の大小を判定し（６２）、総負荷が増加する場合にはバイパス弁５２を閉方向に動作させ（６３）、総負荷が減少する場合にバイパス弁５２をを開方向に動作させる（６４）。こうすることにより、バイパス弁バイパス５２による能力制御が付加され、小容量一定速圧縮機２０と大容量一定速圧縮機２１の同時運転では能力がやや過剰な運転条件などの場合に、特に適した能力制御が可能となる。
【００４９】
次に、総負荷が高負荷側設定値より小の場合は、総負荷と低負荷側設定値と大小を判定し（６５）、大の場合には大容量一定速圧縮機２１が連続運転し、小容量一定速圧縮機２０を停止させる（６６）。
【００５０】
さらに、総負荷の値の大小を判定し（６７）、総負荷が増加する場合にはバイパス弁５２を閉方向に動作させ（６８）、総負荷が減少する場合にはバイパス弁５２開方向に動作させる（６９）。
【００５１】
ここにおいても、バイパス弁５２による能力制御が付加されるので、大容量一定速圧縮機２１のみの運転では能力がやや過剰な運転条件などの場合に、特に適した能力制御が可能となる。
【００５２】
次に、総負荷が低負荷側設定値より小の場合には大容量一定速圧縮機２１を停止し、小容量一定速圧縮機２０を連続運転させる（７０）。さらに、総負荷の値の大小を判定し（７１）、総負荷が増加する場合にはバイパス弁５２を閉方向に動作させ（７２）、総負荷が減少する場合にはバイパス弁５２を開方向に動作させる（７３）。こうすることにより、総負荷が低負荷側設定値より小さい場合にも、小容量一定速圧縮機の運転／停止ではなく、バイパス弁５２の開度を制御して能力制御することにより、小さい負荷の場合にもきめ細かい能力制御ができるので、より広い範囲で負荷に対応した運転ができるものである。
【００５３】
以上のように、各圧縮機の運転台数制御に加え、バイパス弁５２による能力制御を付加したので０ＨＰ〜１０ＨＰまでの広い範囲で、きめ細かな能力制御が可能となるものである。
【００５４】
（実施例４）
図６は本発明の実施例４による多室型空気調和機の運転制御フローチャートを示す。また、ここで示すシステム構成図は図３と同様であり、説明は省略し、各圧縮機の制御およびバイパス弁５２の制御について説明する。
【００５５】
総負荷検知手段３５で検知された総負荷と高負荷側設定値との大小を判定し（６０）、大の場合は大容量一定速圧縮機２１（６ＨＰ）および小容量一定速圧縮機２０（４ＨＰ）を連続運転させる（６１）。さらに、総負荷の値の大小を判定し（６２）、総負荷が増加する場合にはバイパス弁５２を閉方向に動作させ（６３）、総負荷が減少する場合にはバイパス弁５２を開方向に動作させる（６４）。ここで、総負荷と高負荷側設定値との差を比較し（８０）、その差が一定値以上の場合には、引き続き大容量一定速圧縮機２１（６ＨＰ）および小容量一定速圧縮機２０（４ＨＰ）を連続運転させ、バイパス弁５２を動作させる。一方、総負荷と高負荷側設定値との差が一定値以下の場合には、大容量一定速圧縮機を連続運転させ、小容量一定速圧縮機２０を総負荷の値の大小や適正な圧力範囲になるように運転／停止を制御する（６６）。こうすることにより、６ＨＰ〜１０ＨＰの範囲の負荷に対応できる制御てなるばかりでなく、バイパス弁５２による能力制御が付加されるので、小容量一定速圧縮機２０と大容量一定速圧縮機２１の同時運転では能力がやや過剰な運転条件などの場合に、特に適した能力制御が可能となり、さらに、バイパス弁５２用いる負荷範囲を設定して、バイパス量が多くなる場合には圧縮機の台数制御に切り替えるようにしたので、バイパス量が過剰となって起こる効率の低下を防ぐことができ、常に負荷に対応した最適なサイクルで運転することが可能となる。
【００５６】
次に、総負荷が高負荷側設定値より小の場合は、総負荷と低負荷側設定値と大小を判定し（６５）、大の場合には大容量一定速圧縮機２１が連続運転し、小容量一定速圧縮機２０を停止させる（６６）。
【００５７】
さらに、総負荷の値の大小を判定し（６７）、総負荷が増加する場合にはバイパス弁５２を閉方向に動作させ（６８）、総負荷が減少する場合にはバイパス弁５２を開方向に動作させる（６９）。ここで、総負荷と高負荷側設定値との差を比較し（８２）、一定値以上の場合には、引き続き大容量一定速圧縮機２１（６ＨＰ）のみを連続運転させ、バイパス弁５２を動作させる。一方、総負荷と高負荷側設定値との差が一定値以下の場合には、大容量一定速圧縮機２１と小容量一定速圧縮機２０を総負荷の値の大小や適正な圧力範囲になるように交互に運転させる（８３）。
【００５８】
こうすることにより、先と同じように、４ＨＰ〜６ＨＰの範囲の負荷に対応できる制御となるばかりでなく、バイパス弁５２による能力制御が付加されるので、大容量一定速圧縮機２１のみの運転では能力がやや過剰な運転条件などの場合に、特に適した能力制御が可能となり、さらに、バイパス弁５２を用いる負荷範囲を設定して、バイパス量が多くなる場合には圧縮機の台数制御に切り替えるようにしたので、バイパス量が過剰となって起こる効率の低下を防ぐことができ、常に負荷に対応した最適な圧縮機台数およびサイクルで運転することが可能となる。
【００５９】
次に、総負荷が低負荷側設定値より小の場合には大容量一定速圧縮機２１を停止し、小容量一定速圧縮機２０を連続運転させる（７０）。さらに、総負荷の値の大小を判定し（７１）、総負荷が増加する場合にはバイパス弁５２を閉方向に動作させ（７２）、総負荷が減少する場合にはバイパス弁５２を開方向に動作させる（７３）。こうすることにより、総負荷が低負荷側設定値より小さい場合にも、小容量一定速圧縮機の運転／停止ではなく、バイパス弁５２の開度を制御して能力制御することにより、小さい負荷の場合にもきめ細かい能力制御ができるので、より広い範囲で負荷に対した運転ができるものである。
【００６０】
以上のように、各圧縮機の運転台数制御に加え、バイパス弁５２による能力制御を付加したので０ＨＰ〜１０ＨＰまでの広い範囲でのきめ細かな能力制御が可能となり、また、バイパス量の過剰な場合には圧縮機台数制御に切り換えるようにしたので、バイパス量増加による効率の低下を防止しながら、常に高効率な圧縮機台数で運転することができるものである。
【００６１】
【発明の効果】
以上のように、本発明による多室型空気調和機では、室内機の総負荷と高負荷側設定値、低負荷側設定値を比較し、その比較結果に応じて大容量一定速圧縮機及び小容量一定速圧縮機の運転／停止をさせることにより、簡単な運転台数制御で負荷変動に対応した運転ができ、あらゆる負荷の状況でも連続した能力制御が可能となり、能力の過不足は起こることなく、常に高効率な運転が可能となる。
【００６２】
また、吐出系統と吸入系統を接続するバイパス弁を有するバイパス管を設け、総負荷が低負荷側設定値より小さく、総負荷と低負荷側設定値との差が大きい場合には前記バイパス弁を開方向に動作させることにより、総負荷が低負荷側設定値より小さい場合に、吐出ガスの吸入系統へバイパス量を調整することにより、冷凍サイクルの冷媒循環量を減少させて、負荷が小さい場合にもきめ細かい能力制御が可能となる。
【００６３】
さらにまた、総負荷が高負荷側設定値より大きい場合においても、吐出ガスの吸入系統へのバイパス量を調整することにより、冷凍サイクルの冷媒循環量を減少させてきめ細かい能力制御を可能とし、また、バイパス量の過剰な場合には圧縮機台数制御に切り換えるようにしたので、バイパス量増加による効率の低下を防止しながら、常に高効率な圧縮機台数で運転することができるなど多大な効果を有するものである。
【図面の簡単な説明】
【図１】本発明の実施例１による多室型空気調和機のシステム構成図
【図２】本発明の実施例１による多室型空気調和機の制御フローチャート
【図３】本発明の実施例２による多室型空気調和機のシステム構成図
【図４】本発明の実施例２による多室型空気調和機の制御フローチャート
【図５】本発明の実施例３による多室型空気調和機の制御フローチャート
【図６】本発明の実施例４による多室型空気調和機の制御フローチャート
【図７】従来の多室型空気調和機のシステム構成図
【符号の説明】
２０小容量一定速圧縮機
２１大容量一定速圧縮機
２２ａ，２２ｂ逆止弁
２３四方弁
２４室外側熱交換器
２５アキュムレータ
２６均油管
２７室外側膨張弁
２８室外ユニット
２９ａ，２９ｂ，２９ｃ，２９ｄ室内ユニット
３０ａ，３０ｂ，３０ｃ，３０ｄ室内側膨張弁
３１ａ，３１ｂ，３１ｃ，３１ｄ室内側熱交換器
３２ガス側主配管
３２ａ，３２ｂ，３２ｃ，３２ｄガス側支管
３３液側主配管
３３ａ，３３ｂ，３３ｃ，３３ｄ液側支管
３４ａ，３４ｂ，３４ｃ，３４ｄ室温センサー
３５総負荷検知手段
３６負荷比較手段
３７複数圧縮機発停制御手段
５０吐出管
５１吸入管
５２バイパス弁
５３システム能力制御手段[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a multi-room air conditioner equipped with a plurality of compressors, and more particularly to capacity control of the outdoor unit.
[0002]
[Prior art]
FIG. 7 is a system configuration diagram of a conventional multi-chamber air conditioner described in Japanese Patent Application Laid-Open No. 63-295880, wherein 1 is a first compressor having a small capacity and capable of pole number conversion. Control of 4HP and 2HP is possible. Reference numeral 2 denotes a second compressor capable of pole conversion with a large capacity, and the capacity can be controlled to 6HP and 3HP.
[0003]
3a and 3b are check valves for preventing the refrigerant from stagnation in the compressor on the stop side when one of the first compressor 1 or the second compressor 2 is operated and the other is stopped. The heat exchanger 5 and the accumulator 6 are oil equalizing pipes that make the level of the refrigerating machine oil in the first compressor 1 and the second compressor 2 the same, and these are accommodated in the outdoor unit 7. Reference numerals 8a, 8b, 8c, and 8d are units each having indoor side pressure reducing devices 9a, 9b, 9c, and 9d having fully closed functions and indoor side heat exchangers 10a, 10b, 10c, and 10d.
[0004]
Here, the indoor units 8a and 8c have a capacity of 3HP, and the indoor units 8b and 8d have a capacity of 2HP.
The indoor units 8a, 8b, 8c, 8d and the outdoor unit 7 are composed of a gas side branch pipe 11a, 11b, 11c, 11d and a liquid side branched from the gas side main pipe 11, the liquid side main pipe 12, and the gas side main pipe 11. The branch pipes 12a, 12b, 12c, and 12d communicate with each other.
[0005]
Next, the operation of the conventional multi-room air conditioner will be described below.
The refrigerant discharged from the first compressor 1 and the second compressor passes through the check valves 3a and 3b and is sent to the outdoor heat exchanger 4 to be condensed and liquefied to be liquid side main pipe 12 and liquid side branch pipes 12a and 12b. , 12c, 12d to be sent to the indoor units 8a, 8b, 8c, 8d. Here, the pressure is reduced by the indoor side pressure reducing devices 9a, 9b, 9c, 9d, evaporated by the indoor side heat exchangers 10a, 10b, 10c, 10d, gasified to contribute to cooling, and the gas side branch pipes 11a, 11b, 11c. 11d and the gas-side main pipe 11 are sent to the outdoor unit 7 and returned from the accumulator 5 to the first compressor 1 and the second compressor and circulate.
[0006]
Here, for example, when four indoor units 8a, 8b, 8c, and 8d are operating, if the indoor unit 8a having a capacity of 3HP stops operating, the indoor operating capacity is 70%, and the capacity of 6HP is By reducing the number of poles of the 2 compressor 2 from 2 poles to 4 poles and reducing the capacity of the second compressor 2 by half, the capacity of the outdoor unit 7 becomes 7 HP (70%), and the outdoor unit capacity corresponding to the indoor operating capacity is increased. Can be output.
[0007]
According to this conventional multi-room type air conditioner, the capacity ratio between the first compressor 1 and the second compressor 2 that can convert two poles and four poles is 2 to 3 (2 poles 4HP vs 6HP, 4 poles). (2HP vs. 3HP), the capacity can be controlled in 8 stages, and multiple different horsepower indoor units can be operated individually, and the capacity of the outdoor unit can be easily changed to the operating capacity of the indoor unit even if the operating capacity changes. Since they can be combined, the system configuration is simplified and efficient operation can be realized.
[0008]
[Problems to be solved by the invention]
However, in such a conventional multi-chamber air conditioner, since it is staged control using a polar compressor, it is necessary to change the number of poles together with the change in the number of operating compressors. The number of times increased and the control became complicated.
[0009]
In addition, the capacity ratio between the first compressor 1 and the second compressor 2 is set to 2 to 3, and each compressor can be converted into two poles and four poles, and by combining them, the stage control of the capacity (2HP -10HP, ie 20%, 30%, 40%,..., 100% operation), but if an intermediate capacity between these stages is required, for example, an indoor unit of 3.5 HP is operated In this case, the capacity control of 35% is required, but here, since the step control is performed every 10%, the first compressor 1 is stopped and the second compressor 2 is operated with four poles. (30%) 4HP (40%), which cannot satisfy the capacity of the outdoor unit of 3.5 HP, becomes insufficient, and the first compressor 1 is operated with two poles and the second compressor 2 is stopped. During operation, the capacity will be excessive and pressure will be reduced. Must be reduced capacity excessively reduced pressure at location, there is a problem that the operating efficiency decreases.
[0010]
The present invention solves the conventional problems, and with a simple configuration and control, it becomes possible to control the capacity according to the load regardless of the size of the load. A multi-room air conditioner capable of efficient operation is provided.
[0011]
[Means for Solving the Problems]
In order to achieve this object, the present invention comprises a large-capacity constant speed compressor and a small-capacity constant-speed compressor, a high-load side set value corresponding to the total load of the indoor unit and the capacity of the large-capacity constant-speed compressor, By comparing the setting value on the low load side corresponding to the capacity of the constant capacity compressor, and by operating / stopping the large capacity and small capacity constant speed compressors according to the comparison results, it is easy even under any load conditions. A wide range of capacity control is possible with simple control, and highly efficient operation is possible.
[0012]
In addition, when the total load is smaller than the low load side set value and the difference between the total load and the low load side set value is large, the bypass valve connecting the discharge system and the suction system is operated in the opening direction to By adjusting the amount of bypass to the gas intake system, fine capacity control is possible even when the load is small. Furthermore, by adjusting the bypass amount according to the difference between the total load and the set value, it is possible to control the capacity over a wide range, and when the bypass amount is excessive, it is switched to the compressor number control. Thus, highly efficient operation can be performed while preventing a decrease in efficiency due to an increase in the bypass amount.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
The present invention includes a large-capacity constant speed compressor, a small-capacity constant speed compressor, a four-way valve, an outdoor heat exchanger, an outdoor unit comprising an outdoor throttle device, a plurality of indoor side exchangers, and an indoor throttle device. A load that substantially corresponds to the operating capacity of the small-capacity constant-speed compressor is configured by connecting an indoor unit to form a refrigerant circuit, with a load substantially corresponding to the operating capacity of the large-capacity constant-speed compressor as a high-load side set value. A low load side set value, a total load detection means for detecting the total load of the plurality of indoor units, a load comparison means for comparing the total load, the high load side set value and the low load side set value, When the total load is larger than the set value on the high load side based on the result of comparison by the load comparison means, the small-capacity constant speed compressor starts and stops, and the large-capacity constant speed compressor operates continuously. In addition, the total load is the high load side set value and the low load side In the middle of a fixed value, the small-capacity constant-speed compressor and the large-capacity constant-speed compressor start and stop alternately, and when the total load is smaller than the stop-load side set value, the large-capacity constant speed compressor A plurality of compressor start / stop control means for stopping and starting and stopping the small capacity constant speed compressor is provided.
[0014]
In addition, a bypass pipe having a bypass valve for connecting a discharge system and a suction system of the large-capacity constant speed compressor and the small-capacity constant speed compressor is provided, and the small capacity is constant when the total load is smaller than a low load side set value. The high speed constant speed compressor is continuously operated and the large capacity constant speed compressor is stopped, and system capacity control means for opening and closing the bypass valve according to the difference between the total load and the low load side set value is provided.
[0015]
Further, when the total load is larger than the high load side set value, the small capacity constant speed compressor and the large capacity constant speed compressor are continuously operated, and according to the difference between the total load and the high load side set value. When the bypass valve is opened and closed and the total load is between the high load side set value and the low load side set value, the small capacity constant speed compressor stops and the large capacity constant speed compressor operates continuously. The bypass valve is opened and closed according to the difference between the total load and the high load side set value, and when the total load is smaller than the low load side set value, the small capacity constant speed compressor continuously operates, The constant speed compressor is stopped, and system capability means for opening and closing the bypass valve according to the difference between the total load and the high load side set value is provided.
[0016]
Further, when the total load is larger than the high load side set value, the small capacity constant speed compressor and the large capacity constant speed compressor are continuously operated, and the bypass is set according to the difference between the total load and the high load side set value. When the valve is opened and closed and the difference between the total load and the high load side set value exceeds the specified value, the bypass valve is closed and the small-capacity constant-speed compressor starts and stops and the large-capacity constant-speed compressor When the total load is between the high load side set value and the low load side set value, the small capacity constant speed compressor stops, the large capacity constant speed compressor operates continuously, and the total load is The bypass valve is opened and closed according to the difference between the load and the high load side set value, and when the difference between the total load and the high load side set value exceeds a predetermined value, the bypass valve is closed and the small capacity is set. The constant speed compressor and the large capacity constant speed compressor start and stop alternately, and the total load is smaller than the low load side set value. System capacity control means for continuously operating the small capacity constant speed compressor, stopping the large capacity constant speed compressor, and opening and closing the bypass valve according to the difference between the total load and the set value on the high load side. It is to be provided.
[0017]
If the total load is smaller than the low load side set value, the large-capacity constant-speed compressor stops, the small-capacity constant-speed compressor operates continuously, and the difference between the total load and the low load side set value is met. When the bypass valve is opened and closed and the total load is smaller than the predetermined value, the system is provided with a system capacity control means for stopping the large capacity constant speed compressor and starting and stopping the small capacity constant speed compressor. .
[0018]
When the total load is between the high load side set value and the low load side set value, and the small capacity constant speed compressor and the large capacity constant speed compressor start and stop alternately, the small capacity constant speed compressor The operation start of the large capacity constant speed compressor and the operation stop of the large capacity constant speed compressor are substantially simultaneous, and the operation stop of the small capacity constant speed compressor and the operation start of the large capacity constant speed compressor are approximately simultaneous. It is.
[0019]
When the total load is halfway between the high load side set value and the stop load side set value, when the small capacity constant speed compressor and the large capacity constant speed compressor start and stop alternately, the It controls the ratio between the operation time of the constant capacity compressor and the operation time of the large capacity constant speed compressor.
[0020]
Since the present invention has the above-described configuration, the total load of the indoor unit is detected, the preset high load set value, the stop load set value, and the total load are compared, and the total load is high load. If it is larger than the set value, the large-capacity constant-speed compressor is operated continuously, and the small-capacity constant-speed compressor is controlled to operate or stop according to the total load. It becomes possible to drive with the ability. When the total load is between the high load side set value and the low load side set value, the small-capacity constant speed compressor and the large-capacity constant speed compressor are alternately started and stopped, and each compressor is started and stopped. In the case of a moderate load, it is possible to operate with a capacity corresponding to that. If the total load is smaller than the set value on the stop load side, the large-capacity constant-speed compressor is stopped, and the small-capacity constant-speed compressor is controlled to operate or stop depending on the total load. In this case, it is possible to operate at a capacity that matches that, and it is possible to perform continuous capacity control in a wide range of load conditions with simple control of the number of operating compressors. It becomes possible. In addition, a bypass pipe having a bypass valve for connecting the discharge system and the suction system is provided, and when the difference between the total load and the low load side set value is large, the bypass valve is operated in the opening direction so that the total load is reduced. Refrigerant circulation in the refrigeration cycle by adjusting the bypass amount of the discharge gas to the intake system by stopping the large-capacity constant-speed compressor, continuously operating the small-capacity constant-speed compressor, and adjusting the bypass amount of the discharge gas to the intake system. By reducing the amount, fine capacity control is possible even when the load is small.
[0021]
Also, if the total load is greater than the high load side set value, continuously operate the small capacity constant speed compressor and the large capacity constant speed compressor, and if the difference between the total load and the high load side set value is large When the bypass is operated in the opening direction and the bypass amount to the intake system for the discharge gas is adjusted, the refrigerant circulation amount in the refrigeration cycle is reduced to enable fine capacity control, and the difference exceeds a certain value Therefore, it is possible to control the capacity to follow a large load fluctuation by starting and stopping a small capacity constant speed compressor and continuously operating the large capacity constant speed compressor. In addition, when the total load is smaller than a predetermined value, the large capacity constant speed compressor is stopped, and the small capacity constant speed compressor is provided with system capacity control means for starting and stopping, so that it cannot be controlled by bypass. Even in the load, the capacity can be reliably controlled, and the efficiency is not lowered as the bypass amount increases.
[0022]
In the case of alternating operation of a small capacity constant speed compressor and a large capacity constant speed compressor, the operation / stop of the small capacity constant speed compressor and the stop / operation of the large capacity constant speed compressor are substantially simultaneously When the compressor is switched, a large pressure fluctuation or the like does not occur, and therefore, there is no loss of capacity and input associated with starting and stopping.
[0023]
In addition, when the total load is between the high load side set value and the stop load side set value, the small capacity constant speed compressor and the large capacity constant speed compressor start and stop alternately, and the small capacity depends on the total load. By controlling the ratio of the operation time of the constant speed compressor and the operation time of the large capacity constant speed compressor, it can be continuously applied from the small capacity constant speed compressor to the load equivalent to the capacity of the large capacity constant speed compressor. Moreover, detailed capability control is possible.
[0024]
【Example】
Hereinafter, an embodiment of a multi-room air conditioner according to the present invention will be described with reference to the drawings.
[0025]
Example 1
FIG. 1 is a system configuration diagram of a multi-room air conditioner according to Embodiment 1 of the present invention. Reference numeral 20 denotes a small capacity constant speed compressor with a small capacity, and the capacity is 4 HP. 21 is a large capacity constant speed compressor having a large capacity, and the capacity is 6 HP.
[0026]
22a and 22b are check valves for preventing refrigerant stagnation in the compressor on the stop side when one of the small capacity constant speed compressor 20 or the large capacity constant speed compressor 21 is operated and the other is stopped, 23 is a four-way valve, 24 is an outdoor heat exchanger, 25 is an accumulator, 26 is an oil equalizing pipe that equalizes the level of refrigeration oil in the small-capacity constant-speed compressor 20 and the large-capacity constant-speed compressor 21, and 27 is a chamber These are outer expansion valves (outdoor throttle devices), which are housed in an outdoor unit (outdoor unit) 28.
[0027]
Reference numerals 29a, 29b, 29c, and 29d denote indoor units (indoor units), which are indoor expansion valves (indoor expansion devices) 30a, 30b, 30c, and 30d and indoor heat exchangers 31a and 31b each having a fully closed function. , 31c, 31d. The indoor units 29a, 29b, 29c, and 29d and the outdoor unit 28 include gas branch pipes 32a, 32b, 32c, and 32d branched from the gas side main pipe 32, the liquid side main pipe 33, and the gas side main pipe 32, and the liquid side branch pipe. 33a, 33b, 33c, and 33d communicate with each other.
[0028]
Reference numerals 34 a, 34 b, 34 c and 34 d are room temperature sensors for measuring the room temperature of each of the indoor units 29 a, 29 b, 29 c and 29 d, and their outputs are sent to the total load detecting means 35. Here, the total load of the indoor unit in operation can be detected and calculated. Reference numeral 36 denotes load comparing means for comparing the total load calculated by the total load detecting means 35 with a preset high load side value and a low load side set value. Reference numeral 37 denotes a plurality of compressor start / stop control means for controlling the operation and stop of the small capacity constant speed compressor 20 and the large capacity constant speed compressor 21 based on the comparison result of the load comparison means 36.
[0029]
Next, the operation of the multi-room air conditioner will be described here taking the cooling operation as an example.
[0030]
The refrigerant discharged from the small-capacity constant-speed compressor 20 and the large-capacity constant-speed compressor 21 is sent to the outdoor heat exchanger 24 through the check valves 22a and 22b and the check valve 23, and is condensed and liquefied. It is sent to the indoor units 29a, 29b, 29c, 29d through the expansion valve 27, the liquid side main pipe 33, and the liquid side branch pipes 33a, 33b, 33c, 33d. Further, the pressure is reduced by the indoor side expansion valves 30a, 30b, 30c, 30d, evaporated by the indoor side heat exchangers 31a, 31b, 31c, 31d, contributed to cooling, gasified, and gas side branch pipes 32a, 32b, 32c, 32d and the gas side main pipe 32 are sent to the outdoor unit 28, pass through the four-way valve 23 and the accumulator 25, and return to the small capacity constant speed compressor 20 and the large capacity constant speed compressor 21 for circulation.
[0031]
On the other hand, the room temperature of each indoor unit 29a, 29b, 29c, 29d is measured by the room temperature sensors 34a, 34b, 34c, 34d, and the value of each room temperature is sent to the total load detecting means 25 for detecting the total load. Here, the total load is calculated by calculating Equation (1) from the difference between the preset target set temperature of each indoor unit and the room temperature and the capacity (number of HPs) of the indoor unit during operation.
[0032]
Total load = HP number of Σ indoor units × (room temperature−target set temperature) Equation (1)
Further, a load corresponding to the operating capacity of the large-capacity constant speed compressor 21 (equivalent to 6HP) is set as a high load side set value, and a load corresponding to the operating capacity of the small capacity constant-speed compressor 20 (equivalent to 4HP) is set to the low load side. Set as a set value. Based on the comparison result between the total load calculated by the total load detecting means 35 and the set value of the high load side and the set value of the low load side, the small capacity constant speed compressor 20 and the large capacity constant speed compressor 21 Controls running and stopping. This will be described with reference to an operation control flowchart shown in FIG.
[0033]
The magnitude of the total load detected by the total load detecting means 35 and the set value on the high load side is determined (40). If large, the large-capacity constant speed compressor 21 (6HP) is continuously operated and the small-capacity constant-speed compression is performed. The machine 20 (4HP) controls the operation / stop so that the value of the total load is within a proper pressure range (41). By doing so, the control can cope with a load in the range of 6HP to 10HP.
[0034]
Further, when the total load is smaller than the high load side set value, the total load and the low load side set value and the magnitude are determined (42). When the total load is large, the large capacity constant speed compressor 21 and the small capacity constant speed are determined. By alternately operating the compressor 20 so that the value of the total load is large or within an appropriate pressure range, control corresponding to a load in the range of 4HP to 6HP is possible (43).
[0035]
That is, here, by controlling the ratio of the operation time of the small-capacity constant-speed compressor 20 and the large-capacity constant-speed compressor 21, continuous and detailed capacity control of 4HP to 6HP becomes possible.
[0036]
Further, when the total load is smaller than the set value on the low load side, the large-capacity constant-speed compressor 21 is stopped, and the small-capacity constant-speed compressor 20 is adjusted so that the total load value is large or small and within an appropriate pressure range. By controlling the operation / stop, the capability control corresponding to the load in the range of 0HP to 4HP becomes possible (44).
[0037]
On the other hand, when the small-capacity constant-speed compressor 20 and the large-capacity constant-speed compressor 21 are alternately operated, the small-capacity constant-speed compressor 20 and the large-capacity constant-speed compressor 21 are almost simultaneously operated. For example, since there is no large pressure fluctuation at the time of switching the compressor, the pressure of the refrigeration cycle is almost maintained, so that the capacity and input loss caused by starting the small capacity constant speed compressor 20 are eliminated. is there.
[0038]
As described above, simple control of the number of operating two constant speed compressors with different capacities makes it possible to operate in a wide range of loads (0 HP to 10 HP in this case), resulting in excessive or insufficient capacity. It can always be operated with a highly efficient cycle. In particular, in this embodiment, in the range of 4 HP to 6 HP, almost continuous fine capacity control is possible by operating the small capacity constant speed compressor 20 and the large capacity constant speed compressor 21 alternately according to the load. Yes, high-efficiency operation that always responds to load fluctuations can be realized.
[0039]
In the present embodiment, the small-capacity constant-speed compressor 20 is described as 4 HP, and the large-capacity constant-speed compressor 21 is described as 6 HP. However, the present invention is not limited to this, and any combination of capacities is included in the present invention. It is.
[0040]
Further, in the present embodiment, the total load in the total load detecting means 35 has been described as expressed by the formula (1). The same applies to the load and the like, and these are included in the present invention.
[0041]
(Example 2)
FIG. 3 is a system configuration diagram of the multi-room air conditioner according to the second embodiment of the present invention. Components having the same functions as those in FIG. 1 are denoted by the same reference numerals, and description thereof is omitted. .
[0042]
Here, a discharge pipe 50 between the check valves 22 a and 22 b and the four-way valve 23 and a suction pipe 51 between the accumulator 25 and the four-way valve 23 are connected via a bypass valve 52. Further, based on the comparison result of the load comparison means 36, a system capacity control means 53 for controlling the operation and stop of the small capacity constant speed compressor 20 and the large capacity constant speed compressor 21 and controlling the opening degree of the bypass valve 52 is provided. Provided.
[0043]
Here, the small-capacity constant speed compressor 20 and the large-capacity constant are based on the comparison result between the total load calculated by the total load detecting means 35 and the preset high-load-side set value and low-load-side set value. The operation and stop of the high speed compressor 21 and the opening degree of the bypass valve 52 are controlled. This will be described with reference to an operation control flowchart shown in FIG. In this case as well, the same flow numbers as those shown in FIG.
[0044]
When the total load detected by the total load detecting means 35 is smaller than the high load side set value, the magnitude of the total load and the low load side set value is determined (42), and the total load is determined from the low load side set value. If it is small, the large capacity constant speed compressor 21 is stopped and the small capacity constant speed compressor 20 is continuously operated (53). Further, the value of the total load is determined (54). When the total load increases, the bypass valve 52 is operated in the opening direction (55). When the total load decreases, the bypass valve 52 is opened. (56). In this way, when the load has decreased, the discharge gas of the small-capacity constant-speed compressor 20 is bypassed from the discharge pipe 50 to the suction pipe 51 via the bypass valve 52, and the refrigerant circulation amount to the refrigeration cycle Can be reduced to reduce ability.
[0045]
That is, when the total load is smaller than the low load side set value, continuous and fine capacity control by opening degree control of the bypass valve 52 can be performed instead of operation / stop of the small capacity constant speed compressor. Stable operation can be performed without large capacity fluctuations accompanying operation / stop.
[0046]
On the other hand, the magnitude of the value of the total load is determined (54), and if it is smaller than the predetermined value, the large-capacity constant speed compressor is stopped, and the magnitude of the total load value is determined only by the small-capacity constant-speed compressor. If it is started and stopped so as to be within an appropriate pressure range, it is possible to reliably control the capacity even with a small load that cannot be controlled by bypass, and there is no decrease in efficiency due to an increase in the amount of bypass. .
[0047]
Example 3
FIG. 5 shows an operation control flowchart of the multi-room air conditioner according to the third embodiment of the present invention. The system configuration diagram shown here is the same as that in FIG. 3, and the description thereof will be omitted. Control of each compressor and control of the bypass valve 52 will be described.
[0048]
The total load detected by the total load detecting means 35, the set value on the high load side, and the magnitude are determined (60). If large, the large-capacity constant speed compressor 21 (6HP) and the small-capacity constant speed compressor 20 (4HP) ) Is continuously operated (61). Further, the magnitude of the value of the total load is determined (62). When the total load increases, the bypass valve 52 is operated in the closing direction (63), and when the total load decreases, the bypass valve 52 is opened. (64). In this way, capacity control by the bypass valve bypass 52 is added, which is particularly suitable when the capacity is slightly excessive in the simultaneous operation of the small capacity constant speed compressor 20 and the large capacity constant speed compressor 21. Capability control is possible.
[0049]
Next, when the total load is smaller than the high load side set value, the total load and the low load side set value and the magnitude are determined (65). When the total load is large, the large capacity constant speed compressor 21 is continuously operated. Then, the small capacity constant speed compressor 20 is stopped (66).
[0050]
Further, the value of the total load is determined (67). When the total load increases, the bypass valve 52 is operated in the closing direction (68). When the total load decreases, the bypass valve 52 is opened. Operate (69).
[0051]
Also here, since the capacity control by the bypass valve 52 is added, the capacity control is particularly suitable in the case where the capacity is slightly excessive in the operation of the large capacity constant speed compressor 21 alone.
[0052]
Next, when the total load is smaller than the set value on the low load side, the large-capacity constant speed compressor 21 is stopped and the small-capacity constant speed compressor 20 is continuously operated (70). Further, the value of the total load is determined (71). When the total load increases, the bypass valve 52 is operated in the closing direction (72). When the total load decreases, the bypass valve 52 is opened. (73). In this way, even when the total load is smaller than the low load side set value, the small capacity constant speed compressor is not operated / stopped, but the opening degree of the bypass valve 52 is controlled to control the capacity, thereby reducing the load. In this case, detailed capability control can be performed, so that operation corresponding to the load can be performed in a wider range.
[0053]
As described above, since the capacity control by the bypass valve 52 is added in addition to the operation number control of each compressor, fine capacity control is possible in a wide range from 0 HP to 10 HP.
[0054]
Example 4
FIG. 6 shows an operation control flowchart of the multi-room air conditioner according to the fourth embodiment of the present invention. The system configuration diagram shown here is the same as that in FIG. 3, and the description thereof will be omitted. Control of each compressor and control of the bypass valve 52 will be described.
[0055]
It is determined whether the total load detected by the total load detecting means 35 and the set value on the high load side are large (60). If large, the large-capacity constant-speed compressor 21 (6HP) and the small-capacity constant-speed compressor 20 ( 4HP) is operated continuously (61). Further, the magnitude of the value of the total load is determined (62). When the total load increases, the bypass valve 52 is operated in the closing direction (63), and when the total load decreases, the bypass valve 52 is opened. (64). Here, the difference between the total load and the set value on the high load side is compared (80). If the difference is equal to or greater than a certain value, the large-capacity constant-speed compressor 21 (6HP) and the small-capacity constant-speed compressor continue. 20 (4HP) is continuously operated, and the bypass valve 52 is operated. On the other hand, if the difference between the total load and the set value on the high load side is less than a certain value, the large-capacity constant-speed compressor is operated continuously, and the small-capacity constant-speed compressor 20 The operation / stop is controlled so as to be in the pressure range (66). By doing so, not only control capable of responding to loads in the range of 6 HP to 10 HP but also capacity control by the bypass valve 52 is added, so that the small capacity constant speed compressor 20 and the large capacity constant speed compressor 21 can be controlled. In simultaneous operation, capacity control that is particularly suitable is possible when the capacity is slightly excessive, and further, the load range used by the bypass valve 52 is set, and if the bypass amount increases, the number of compressors can be controlled. Therefore, it is possible to prevent a decrease in efficiency caused by an excessive bypass amount, and it is possible to always operate in an optimum cycle corresponding to the load.
[0056]
Next, when the total load is smaller than the high load side set value, the total load and the low load side set value and the magnitude are determined (65). When the total load is large, the large capacity constant speed compressor 21 is continuously operated. Then, the small capacity constant speed compressor 20 is stopped (66).
[0057]
Further, the value of the total load is determined (67). When the total load increases, the bypass valve 52 is operated in the closing direction (68). When the total load decreases, the bypass valve 52 is opened. (69). Here, the difference between the total load and the set value on the high load side is compared (82), and if it is above a certain value, only the large-capacity constant speed compressor 21 (6HP) is continuously operated, and the bypass valve 52 is turned on. Make it work. On the other hand, when the difference between the total load and the set value on the high load side is a certain value or less, the large-capacity constant-speed compressor 21 and the small-capacity constant-speed compressor 20 are adjusted to a large or small value of the total load or an appropriate pressure range. It is made to drive alternately so that (83).
[0058]
By doing so, not only the control that can cope with the load in the range of 4HP to 6HP is performed, but also the capacity control by the bypass valve 52 is added, so that only the large capacity constant speed compressor 21 is operated. Then, particularly suitable capacity control is possible in case of slightly overcapacity operating conditions, and furthermore, by setting a load range using the bypass valve 52, when the bypass amount increases, it is possible to control the number of compressors. Since switching is performed, it is possible to prevent a decrease in efficiency caused by an excessive amount of bypass, and it is possible to always operate with the optimum number of compressors and cycle corresponding to the load.
[0059]
Next, when the total load is smaller than the set value on the low load side, the large-capacity constant speed compressor 21 is stopped and the small-capacity constant speed compressor 20 is continuously operated (70). Further, the value of the total load is determined (71). When the total load increases, the bypass valve 52 is operated in the closing direction (72). When the total load decreases, the bypass valve 52 is opened. (73). In this way, even when the total load is smaller than the low load side set value, the small capacity constant speed compressor is not operated / stopped, but the opening degree of the bypass valve 52 is controlled to control the capacity, thereby reducing the load. In this case, detailed capability control can be performed, so that operation with respect to the load can be performed in a wider range.
[0060]
As described above, in addition to the control of the number of operating units of each compressor, the capability control by the bypass valve 52 is added, so fine capability control over a wide range from 0 HP to 10 HP is possible, and when the bypass amount is excessive. Since the control is switched to the control of the number of compressors, it is possible to always operate with a highly efficient number of compressors while preventing a decrease in efficiency due to an increase in the bypass amount.
[0061]
【The invention's effect】
As described above, in the multi-room air conditioner according to the present invention, the total load of the indoor unit is compared with the set value on the high load side and the set value on the low load side, and according to the comparison result, the large capacity constant speed compressor and By operating / stopping a small-capacity constant-speed compressor, it is possible to operate in response to load fluctuations with simple control of the number of operating units, and continuous capacity control is possible even under any load conditions, resulting in excessive or insufficient capacity. Therefore, highly efficient operation is always possible.
[0062]
Also, a bypass pipe having a bypass valve for connecting the discharge system and the suction system is provided, and when the total load is smaller than the low load side set value and the difference between the total load and the low load side set value is large, the bypass valve is When the total load is smaller than the low load side set value by operating in the open direction, the refrigerant circulation rate of the refrigeration cycle is reduced by adjusting the bypass amount to the discharge gas suction system, and the load is small In addition, detailed ability control is possible.
[0063]
Furthermore, even when the total load is larger than the set value on the high load side, by adjusting the bypass amount of the discharge gas to the intake system, the refrigerant circulation amount of the refrigeration cycle can be reduced and fine capacity control can be performed. When the amount of bypass is excessive, it is switched to the control of the number of compressors, so that it is possible to always operate with a highly efficient number of compressors while preventing a decrease in efficiency due to an increase in the amount of bypass. It is what you have.
[Brief description of the drawings]
FIG. 1 is a system configuration diagram of a multi-room air conditioner according to Embodiment 1 of the present invention.
FIG. 2 is a control flowchart of the multi-room air conditioner according to the first embodiment of the present invention.
FIG. 3 is a system configuration diagram of a multi-room air conditioner according to Embodiment 2 of the present invention.
FIG. 4 is a control flowchart of a multi-room air conditioner according to Embodiment 2 of the present invention.
FIG. 5 is a control flowchart of a multi-room air conditioner according to Embodiment 3 of the present invention.
FIG. 6 is a control flowchart of a multi-room air conditioner according to Embodiment 4 of the present invention.
FIG. 7 is a system configuration diagram of a conventional multi-room air conditioner.
[Explanation of symbols]
20 Small capacity constant speed compressor
21 Large capacity constant speed compressor
22a, 22b Check valve
23 Four-way valve
24 outdoor heat exchanger
25 Accumulator
26 Oil leveling pipe
27 Outdoor expansion valve
28 Outdoor unit
29a, 29b, 29c, 29d Indoor unit
30a, 30b, 30c, 30d Indoor expansion valve
31a, 31b, 31c, 31d Indoor heat exchanger
32 Gas side main piping
32a, 32b, 32c, 32d Gas side branch pipe
33 Liquid side main piping
33a, 33b, 33c, 33d Liquid side branch pipe
34a, 34b, 34c, 34d Room temperature sensor
35 Total load detection means
36 Load comparison means
37 Multiple compressor start / stop control means
50 Discharge pipe
51 Suction pipe
52 Bypass valve
53 System capability control means

Claims

A large-capacity constant-speed compressor, a small-capacity constant-speed compressor, an outdoor unit consisting of a four-way valve, an outdoor heat exchanger, and an outdoor throttle device, and a plurality of indoor units consisting of an indoor heat exchanger and an indoor throttle device Connected to form a refrigerant circuit, a load approximately corresponding to the operating capacity of the large-capacity constant-speed compressor is set to a high load side set value, and a load approximately corresponding to the operating capacity of the small-capacity constant-speed compressor is set to a low load A total load detecting means for detecting a total load of the plurality of indoor units, a load comparing means for comparing the low load side set value as the high load side set value, and the load comparison When the total load is larger than the high load side set value based on the result of comparison by the means, the small-capacity constant speed compressor starts and stops, and the large-capacity constant speed compressor operates continuously, and The total load is the high load side set value and the low load side set value. In the middle case, the small-capacity constant-speed compressor and the large-capacity constant-speed compressor start and stop alternately, and when the total load is smaller than the low load side set value, the large-capacity constant-speed compressor Is a multi-chamber air conditioner provided with a plurality of compressor start / stop control means for stopping and stopping the small capacity constant speed compressor.

A large-capacity constant speed compressor, a small-capacity constant-speed compressor, a four-way valve, an outdoor heat exchanger, an outdoor expansion device, a discharge system and a suction system for the large-capacity constant-speed compressor and the small-capacity constant-speed compressor. A refrigerant circuit is configured by connecting an outdoor unit composed of a bypass pipe having a bypass valve to be connected, and a plurality of indoor units composed of an indoor heat exchanger and an indoor expansion device, so that the operating capacity of the large-capacity constant speed compressor is achieved. A total load detecting means for detecting a total load of the plurality of indoor units by setting a substantially equivalent load as a set value on the high load side, and setting a load substantially corresponding to the operation capacity of the small capacity constant speed compressor as a low load side set value. Load comparing means for comparing the total load with the high load side set value and the low load side set value, and the total load is larger than the high load side set value based on the result of comparison by the load comparison means The small capacity constant speed compressor And when the large-capacity constant-speed compressor operates continuously and the total load is intermediate between the high-load side set value and the low-load side set value, the small-capacity constant-speed compressor and the large-capacity compressor When the capacity constant speed compressor is alternately started and stopped, and the total load is smaller than the set value on the low load side, the large capacity constant speed compressor is stopped and the small capacity constant speed compressor is continuously operated. And a multi-room air conditioner provided with system capability control means for opening and closing the bypass valve in accordance with a difference between the total load and the low load side set value.

A large-capacity constant speed compressor, a small-capacity constant-speed compressor, a four-way valve, an outdoor heat exchanger, an outdoor expansion device, a discharge system and a suction system for the large-capacity constant-speed compressor and the small-capacity constant-speed compressor. A refrigerant circuit is configured by connecting an outdoor unit composed of a bypass pipe having a bypass valve to be connected to a plurality of indoor units composed of an indoor side heat exchanger and an indoor side expansion device. A total load detection that detects a total load of the plurality of indoor units by setting a substantially equivalent load load as a high load side set value and a load substantially corresponding to the operation capacity of the small capacity constant speed compressor as a low load side set value. Means, a load comparison means for comparing the total load with the high load side set value and the low load side set value, and based on the result of comparison by the load comparison means, the total load is greater than the high load side set value. If large, the small capacity constant speed compressor And the large-capacity constant speed compressor operates continuously, and opens and closes the bypass valve according to the difference between the total load and the high load side set value, and the total load is the high load side set value. In the middle of the low load side set value, the small capacity constant speed compressor is stopped, the large capacity constant speed compressor is continuously operated, and the total load and the high load side set value are The bypass valve is opened and closed according to the difference, and when the total load is smaller than the set value on the low load side, the large-capacity constant speed compressor is stopped and the small-capacity constant speed compressor is continuously operated. And a multi-room air conditioner provided with system capability control means for opening and closing the bypass valve in accordance with a difference between the total load and the low load side set value.

A large-capacity constant speed compressor, a small-capacity constant-speed compressor, a four-way valve, an outdoor heat exchanger, an outdoor expansion device, a discharge system and a suction system for the large-capacity constant-speed compressor and the small-capacity constant-speed compressor. A refrigerant circuit is configured by connecting an outdoor unit composed of a bypass pipe having a bypass valve to be connected, and a plurality of indoor units composed of an indoor heat exchanger and an indoor expansion device, so that the operating capacity of the large-capacity constant speed compressor is achieved. A load substantially equivalent to a high load side set value, a load substantially equivalent to the operation capacity of the small-capacity constant speed compressor as a low load side set value, and a total load detecting means for detecting a total load of the plurality of indoor units; The load comparison means for comparing the total load with the high load side set value and the low load side set value, and when the total load is larger than the high load side set value based on the result of comparison by the load comparison means, The small capacity constant speed compressor and the large capacity The constant speed compressor operates continuously, opens and closes the bypass valve according to the difference between the total load and the high load side set value, and the difference between the total load and the high load side set value is predetermined. When the value is less than or equal to the value, the small-capacity constant-speed compressor is started and stopped, the large-capacity constant-speed compressor is continuously operated, the bypass valve is closed, and the total load is the high load side. When the set value is intermediate between the low load side set value and the small capacity constant speed compressor is stopped, the large capacity constant speed compressor is continuously operated, and the total load and the high load side set value are set. When the difference between the total load and the high load side set value is less than or equal to a predetermined value, the small capacity constant speed compressor and the large capacity Constant speed compressors alternately start and stop, the bypass valve is closed, and the total load is If the value is smaller than the low load side set value, the large capacity constant speed compressor stops, the small capacity constant speed compressor continuously operates, and the difference between the total load and the low load side set value is A multi-room air conditioner provided with system capability control means for opening and closing the bypass valve accordingly.

When the total load is smaller than the low load side set value, the large capacity constant speed compressor is stopped, the small capacity constant speed compressor is continuously operated, and according to the difference between the total load and the low load side set value. System capacity control means for stopping the large capacity constant speed compressor and starting and stopping the small capacity constant speed compressor when the bypass valve is opened and closed and the total load is smaller than a predetermined value. The multi-room air conditioner according to claim 2 or 4.

When the total load is between the high load side set value and the low load side set value and the small capacity constant speed compressor and the large capacity constant speed compressor start and stop alternately, the small capacity constant speed compressor The operation start and the operation stop of the large capacity constant speed compressor are substantially simultaneous, and the operation stop of the small capacity constant speed compressor and the operation start of the large capacity constant speed compressor are substantially simultaneous. The multi-room air conditioner according to any one of claims 1, 2, 4 and 5.

When the total load is halfway between the high load side set value and the low load side set value, and the small capacity constant speed compressor and the large capacity constant speed compressor start and stop alternately, the small load depends on the total load. The multi-chamber air conditioner according to any one of claims 1, 2, 4, and 5, wherein a ratio between an operation time of the constant capacity compressor and an operation time of the large capacity constant speed compressor is controlled. .