JPH05332630A - Air conditioner - Google Patents
Air conditionerInfo
- Publication number
- JPH05332630A JPH05332630A JP4139013A JP13901392A JPH05332630A JP H05332630 A JPH05332630 A JP H05332630A JP 4139013 A JP4139013 A JP 4139013A JP 13901392 A JP13901392 A JP 13901392A JP H05332630 A JPH05332630 A JP H05332630A
- Authority
- JP
- Japan
- Prior art keywords
- pressure
- refrigerant
- liquid
- liquid pipe
- indoor
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B2500/00—Problems to be solved
- F25B2500/31—Low ambient temperatures
Landscapes
- Compression-Type Refrigeration Machines With Reversible Cycles (AREA)
- Air Conditioning Control Device (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は空気調和機の冷凍サイク
ルの制御に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to control of a refrigeration cycle of an air conditioner.
【０００２】[0002]
【従来の技術】室外ユニットに複数台の室内ユニットを
配管で接続した所謂マルチ空気調和機において、室外ユ
ニットが室内ユニットより上方（例えば屋上）に設置さ
れ、室内ユニット間に高低差がある場合には、これら室
内ユニットの暖房運転は、ユニット間の高低差分の液ヘ
ッドにより、下方に設置された室内ユニットの暖房能力
の低下を招く。これを防止するための従来技術として、
特開平０３−２９４７５２号公報記載のように、各室内
ユニットの能力を比較し、能力が不足している室内ユニ
ットがあれば、他の上方の室内ユニットのうち能力が最
大の室内ユニットの液配管側に取り付けられている冷媒
流量制御弁を絞る様にしたものがある。2. Description of the Related Art In a so-called multi-air conditioner in which a plurality of indoor units are connected to an outdoor unit by piping, when the outdoor unit is installed above the indoor unit (for example, on the roof) and there is a height difference between the indoor units. In the heating operation of these indoor units, the liquid head having a difference in height between the units causes a decrease in the heating capacity of the indoor unit installed below. As a conventional technique for preventing this,
As described in Japanese Patent Laid-Open No. 03-294752, the capacities of the indoor units are compared, and if there is an indoor unit with insufficient capacity, liquid piping of the indoor unit with the maximum capacity among other upper indoor units. There is one in which the refrigerant flow rate control valve attached to the side is throttled.
【０００３】他方、冷房運転する空気調和機、または室
外熱交換器を凝縮器として冷暖房同時運転（複数の室内
ユニットのうち或るものを冷房運転しつつ同時に他のも
のを暖房運転する運転）をするマルチ空気調和機におい
て、外気温度が低いときに、凝縮器（室外熱交換器）の
凝縮能力が高まることに伴う圧縮機吐出圧力の低下を防
ぐために、特開平０２−２２３７７６号または特開平０
３−１４０７５７号公報記載のように、室外熱交換器出
口の冷媒流量制御弁を絞って流路抵抗を大きくする方
式、又は、圧縮機の吐出ガスの一部をレシーバの入口に
導いてレシーバ内の液冷媒を室外熱交換器に移し、室外
熱交換器の伝熱面積を液冷媒で減少させ、凝縮能力を低
下させて圧縮機の吐出圧力を高める方式のものがあり、
これにより、外気低温時の冷房運転または冷暖房同時運
転が良好に行えるようにしている。On the other hand, an air conditioner that performs cooling operation or an outdoor heat exchanger as a condenser is used for simultaneous cooling and heating operation (operation in which some of the plurality of indoor units are in cooling operation while others are in heating operation). In order to prevent a decrease in compressor discharge pressure due to an increase in the condensation capacity of a condenser (outdoor heat exchanger) when the outside air temperature is low, the multi-air conditioner described in JP-A-02-223776 or JP-A-02-237776.
As described in JP-A-3-140757, a method in which a refrigerant flow rate control valve at the outlet of the outdoor heat exchanger is throttled to increase flow passage resistance, or a part of discharge gas of the compressor is guided to an inlet of the receiver There is a system that transfers the liquid refrigerant of to the outdoor heat exchanger, reduces the heat transfer area of the outdoor heat exchanger with the liquid refrigerant, and reduces the condensation capacity to increase the discharge pressure of the compressor,
As a result, the cooling operation or the cooling / heating simultaneous operation when the outside air temperature is low can be favorably performed.
【０００４】また、他方、空調機の冷凍サイクルの冷媒
封入量を節減することが近年望まれているが、それがで
きる空気調和機として、特開昭６３−１９７８５３号公
報記載のように、凝縮器出口に設置した毛細管で冷媒を
減圧し、液配管内の冷媒を低圧の気液二相流にすること
によって封入冷媒量を節減しているものがある。On the other hand, in recent years, it has been desired to reduce the amount of refrigerant enclosed in the refrigeration cycle of the air conditioner. As an air conditioner capable of achieving this, as described in Japanese Patent Laid-Open No. 63-197853, condensation is performed. In some cases, the amount of enclosed refrigerant is reduced by decompressing the refrigerant with a capillary tube installed at the outlet of the vessel and making the refrigerant in the liquid pipe into a low-pressure gas-liquid two-phase flow.
【０００５】[0005]
【発明が解決しようとする課題】前記第１の従来技術で
は、暖房運転で室内ユニット間に高低差がある場合、下
方の室内ユニットの暖房能力を確保するために、上方の
室内ユニットのうち能力が最大の室内ユニットの冷媒流
量制御弁を絞る様にしているが、それが能力に影響を及
ぼすまでに時間がかかるために、該冷媒流量制御弁が絞
りすぎになって能力低下を招くことがある。In the first prior art, when there is a height difference between the indoor units in the heating operation, in order to secure the heating capacity of the lower indoor unit, the capacity of the upper indoor unit is reduced. Squeezes the refrigerant flow rate control valve of the largest indoor unit, but it takes time to affect the capacity, so the refrigerant flow rate control valve may be too squeezed, leading to reduced capacity. is there.
【０００６】よって、本発明の第１の目的は、室内ユニ
ット間に高低差があるマルチ空調機において、暖房運転
の場合に、各室内ユニットが常に暖房能力を確保し、安
定した運転ができる様にすることである。Therefore, a first object of the present invention is to ensure that in a multi-air conditioner in which there is a difference in height between indoor units, each indoor unit always has a heating capacity and can be operated stably during heating operation. Is to
【０００７】他方、冷房運転又は冷暖房同時運転で外気
温度が低い場合に室外熱交換器出口の冷媒流量制御弁を
絞る前記第２の従来技術の方式では、該弁を絞り過ぎた
とき、液配管内の圧力が異常に低下し、これが冷房室内
ユニットでさらに減圧されるために、圧縮機吸入圧力が
低下し、それに伴って圧縮機吐出圧力も低下する。圧縮
機吐出圧力が低下すると、室外熱交換器出口の冷媒流量
制御弁をさらに絞り、圧縮機の吸入圧力及び吐出圧力と
もさらに低下するという具合になって圧縮機の吸入圧力
および吐出圧力の異常低下を招き、運転不可能となる恐
れがある。On the other hand, in the second prior art method in which the refrigerant flow rate control valve at the outlet of the outdoor heat exchanger is throttled when the outdoor air temperature is low in the cooling operation or the simultaneous heating and cooling operation, when the valve is excessively throttled, the liquid pipe Since the internal pressure is abnormally reduced and is further reduced in the cooling indoor unit, the compressor suction pressure is reduced, and the compressor discharge pressure is also reduced accordingly. When the compressor discharge pressure decreases, the refrigerant flow rate control valve at the outlet of the outdoor heat exchanger is further throttled to further decrease both the suction pressure and the discharge pressure of the compressor, resulting in an abnormal decrease in the suction pressure and the discharge pressure of the compressor. This may lead to driving failure.
【０００８】よって、本発明の第２の目的は、冷房運転
中の空調機、又は室外熱交換器を凝縮器として冷暖房同
時運転中の空調機において、外気温度が低いとき、室外
熱交換器の凝縮能力が高まることに伴う圧縮機吐出圧力
の低下を防ぐために室外熱交換器出口の冷媒流量制御弁
を絞る場合にも、該冷媒流量制御弁の絞りすぎによる圧
縮機の吸入圧力及び吐出圧力の異常低下を招くことなく
安定した運転ができる様にすることである。Therefore, a second object of the present invention is to provide an air conditioner during cooling operation, or an air conditioner during cooling / heating simultaneous operation using the outdoor heat exchanger as a condenser when the outdoor air temperature is low. Even when the refrigerant flow control valve at the outlet of the outdoor heat exchanger is throttled in order to prevent a decrease in the compressor discharge pressure due to an increase in the condensation capacity, the suction pressure and the discharge pressure of the compressor due to the throttle of the refrigerant flow control valve being excessively throttled. This is to enable stable operation without causing an abnormal decrease.
【０００９】冷暖房同時運転で外気温度が低い場合に圧
縮機吐出ガスの一部をレシーバ入口に導いてレシーバ内
の液冷媒を室外熱交換器に移す前記第３の従来技術の方
式は、室外熱交換器出口の冷媒流量制御弁と組み合わせ
て使われる。すなわち、外気温度が非常に低いときは該
冷媒流量制御弁を絞り、外気温度がさほど低くないとき
は該冷媒流量制御弁をあまり絞らないようにしている。
該冷媒流量制御弁を絞っても圧縮機吐出ガスの一部が液
配管側にバイパスされているので液配管内の圧力は大き
く低下することはない。しかし、この方式では、外気温
度がさほど低くないときは、冷媒流量制御弁をあまり絞
らないので、液配管内の圧力は比較的高く、暖房室内ユ
ニットが室外ユニットより下方にある場合には、暖房室
内ユニットに液ヘッドが作用し、暖房室内ユニットの冷
媒出口圧力が上昇して、暖房室内ユニットに冷媒が流れ
にくくなり、暖房能力不足を生じる恐れがある。When the outside air temperature is low in the simultaneous cooling and heating operation, a part of the compressor discharge gas is guided to the receiver inlet to transfer the liquid refrigerant in the receiver to the outdoor heat exchanger. Used in combination with the refrigerant flow control valve at the outlet of the exchanger. That is, when the outside air temperature is very low, the refrigerant flow rate control valve is throttled, and when the outside air temperature is not so low, the refrigerant flow rate control valve is not so throttled.
Even if the refrigerant flow rate control valve is throttled, a part of the compressor discharge gas is bypassed to the liquid pipe side, so that the pressure in the liquid pipe does not significantly decrease. However, in this method, when the outside air temperature is not so low, the refrigerant flow rate control valve is not throttled so much, so the pressure in the liquid pipe is relatively high, and when the heating indoor unit is below the outdoor unit, the heating The liquid head acts on the indoor unit, the refrigerant outlet pressure of the heating indoor unit rises, and it becomes difficult for the refrigerant to flow into the heating indoor unit, which may cause insufficient heating capacity.
【００１０】よって、本発明の第３の目的は、室外熱交
換器を凝縮器として冷暖房同時運転中のマルチ空調機に
おいて、外気温が低いとき、室外熱交換器の凝縮能力が
高まることに伴う圧縮機吐出圧力の低下を防ぐために圧
縮機吐出ガスの一部をレシーバ入口に導いた場合にも、
暖房室内ユニットの能力を確保することである。Therefore, a third object of the present invention is to increase the condensing capacity of the outdoor heat exchanger when the outdoor air temperature is low in a multi air conditioner that is simultaneously operating cooling and heating with the outdoor heat exchanger as a condenser. Even when a part of the compressor discharge gas is introduced to the receiver inlet to prevent the compressor discharge pressure from decreasing,
It is to secure the capacity of the heating indoor unit.
【００１１】凝縮器出口に毛細管を設けて液配管内の冷
媒を低圧の気液二相流にして封入冷媒量を節減する前記
第４の従来技術による空気調和機は、液配管内が気液二
相流なので、液配管内での圧力損失が大きく、配管長に
よって蒸発圧力が大きく変動する。特に、配管長が長い
ときは圧力損失が大きく、蒸発圧力が大幅に低下し、蒸
発器が凍結して空気調和機が停止する恐れがある。だか
らといって、これを防止するために液配管を太くする
と、封入冷媒量節減の目的に反することになる。In the air conditioner according to the fourth prior art in which a capillary tube is provided at the outlet of the condenser to make the refrigerant in the liquid pipe a low-pressure gas-liquid two-phase flow to reduce the amount of the enclosed refrigerant, the inside of the liquid pipe is gas-liquid. Since it is a two-phase flow, the pressure loss in the liquid pipe is large, and the evaporation pressure fluctuates greatly depending on the pipe length. In particular, when the pipe length is long, the pressure loss is large, the evaporation pressure is significantly reduced, and the evaporator may freeze and the air conditioner may stop. However, if the liquid pipe is made thick in order to prevent this, it is against the purpose of saving the amount of the enclosed refrigerant.
【００１２】よって、本発明の第４の目的は、封入冷媒
量節減のための液配管内の冷媒を気液二相状態にする空
気調和機において、液配管内の圧力が所定値より低くな
らないようにして、蒸発器での蒸発圧力の低下を防止す
ることである。Therefore, in a fourth object of the present invention, in an air conditioner for making a refrigerant in a liquid pipe a gas-liquid two-phase state for saving the amount of the enclosed refrigerant, the pressure in the liquid pipe does not become lower than a predetermined value. In this way, the evaporation pressure in the evaporator is prevented from decreasing.
【００１３】[0013]
【課題を解決するための手段】前記第１の目的は、特許
請求の範囲の請求項１又は２記載の、また第２の目的は
請求項３記載の、また第３の目的は請求項４記載の、ま
た第４の目的は請求項５又は６記載の構成によって達成
することができる。The first object is the claim 1 or 2 of the claims, the second object is the claim 3, and the third object is the claim 4. The stated and fourth objects can be achieved by the configurations according to claims 5 and 6.
【００１４】[0014]
【作用】請求項２の空調機においては、室内ユニット間
に高低差がある暖房運転の場合、液ヘッド分の圧力を解
消して下方の室内ユニットの能力を確保するために、上
方の室内ユニットで能力が最大の室内ユニットの冷媒流
量制御弁を絞る。このとき、液冷媒圧力検出手段で液配
管内の圧力を検出しているので、この圧力が所定圧力よ
り下がったときは、上方の室内ユニットの冷媒流量制御
弁を絞らないようにする。これによって、上方の室内ユ
ニットの冷媒流量制御弁の絞りすぎによる能力低下を防
止できる。この場合、液冷媒圧力調整手段は上方室内ユ
ニットの冷媒流量制御弁である。In the air conditioner according to claim 2, in the heating operation in which there is a difference in height between the indoor units, the upper indoor unit is eliminated in order to release the pressure of the liquid head and secure the capacity of the lower indoor unit. Squeeze the refrigerant flow control valve of the indoor unit with the maximum capacity. At this time, since the pressure inside the liquid pipe is detected by the liquid refrigerant pressure detecting means, the refrigerant flow rate control valve of the upper indoor unit is not throttled when this pressure falls below a predetermined pressure. As a result, it is possible to prevent performance deterioration due to excessive throttle of the refrigerant flow rate control valve of the upper indoor unit. In this case, the liquid refrigerant pressure adjusting means is the refrigerant flow rate control valve of the upper indoor unit.
【００１５】請求項３の空調機においては、冷房運転又
は室外熱交換器が凝縮器となる冷暖房同時運転で外気温
度が低い場合、室外熱交換器出口の冷媒流量制御弁を絞
り、圧縮機吐出圧力の低下を防止する。このとき、液冷
媒圧力検出手段で液配管内の圧力を検出しているので、
この圧力が所定圧力より下がったときは、室外熱交換器
出口の冷媒流量制御弁を絞らないようにする。これによ
って、室外熱交換器出口の冷媒流量制御弁の絞りすぎに
よる液配管内圧力の異常低下が防止できる。In the air conditioner of claim 3, when the outside air temperature is low in the cooling operation or the simultaneous heating and cooling operation in which the outdoor heat exchanger serves as a condenser, the refrigerant flow control valve at the outlet of the outdoor heat exchanger is throttled to discharge the compressor. Prevent pressure drop. At this time, since the pressure in the liquid pipe is detected by the liquid refrigerant pressure detection means,
When this pressure falls below a predetermined pressure, the refrigerant flow rate control valve at the outlet of the outdoor heat exchanger is not throttled. As a result, it is possible to prevent an abnormal decrease in the pressure inside the liquid pipe due to the refrigerant flow control valve at the outlet of the outdoor heat exchanger being excessively throttled.
【００１６】請求項４の空調機においては、外気温度が
低いときに、圧縮機吐出ガスの一部をレシーバ入口にバ
イパスする。このとき、液配管内の圧力が所定圧力又は
所定圧力範囲になるように、バイパス回路の流路抵抗を
バイパス流量調整手段によって調整して、バイパス流量
を制御する。これによって、暖房室内ユニットに作用す
る液ヘッドの圧力分だけ液配管内圧力を下げることがで
き、液ヘッドによって生じる暖房能力不足が解消され
る。In the air conditioner of claim 4, when the outside air temperature is low, a part of the compressor discharge gas is bypassed to the receiver inlet. At this time, the flow path resistance of the bypass circuit is adjusted by the bypass flow rate adjusting means to control the bypass flow rate so that the pressure in the liquid pipe becomes a predetermined pressure or a predetermined pressure range. As a result, the pressure in the liquid pipe can be reduced by the pressure of the liquid head acting on the heating indoor unit, and the insufficient heating capacity caused by the liquid head can be eliminated.
【００１７】請求項５の空調機においては、液配管内の
冷媒を気液二相流にして冷媒封入量を節減している。こ
の場合、凝縮器出口の冷媒温度が検出手段によって検出
され、その温度から凝縮器出口の飽和圧力が推定でき
る。また、液冷媒圧力検出手段によって液配管内の圧力
が検出され、液配管内の圧力が前記飽和圧力より低く、
かつ、液配管出口圧力が蒸発器の目標蒸発圧力以上とな
るように、液配管内の圧力を液冷媒圧力調整手段で制御
する。これによって、液配管内を気液二相状態にでき、
しかも、液配管出口の圧力が目標蒸発圧力より高くでき
るので、蒸発器での圧力が大幅に低下することはなくな
る。In the air conditioner of the fifth aspect, the refrigerant in the liquid pipe is made into a gas-liquid two-phase flow to reduce the amount of refrigerant enclosed. In this case, the refrigerant temperature at the outlet of the condenser is detected by the detecting means, and the saturation pressure at the outlet of the condenser can be estimated from the temperature. Further, the pressure in the liquid pipe is detected by the liquid refrigerant pressure detection means, the pressure in the liquid pipe is lower than the saturation pressure,
The pressure in the liquid pipe is controlled by the liquid refrigerant pressure adjusting means so that the liquid pipe outlet pressure becomes equal to or higher than the target evaporation pressure of the evaporator. This allows the liquid pipe to be in a gas-liquid two-phase state,
Moreover, since the pressure at the outlet of the liquid pipe can be made higher than the target evaporation pressure, the pressure in the evaporator will not drop significantly.
【００１８】[0018]
【実施例】本発明の一実施例を図１に示す。本実施例は
暖房専用のマルチ空気調和機であり、その室外ユニット
１は建物の屋上に設置され、圧縮機８１、室外熱交換器
１１、室外冷媒流量制御弁２１、室外ファン３１で構成
されている。また、圧縮機８１の出口には圧力センサ１
７ｃが取り付けられており、これにより圧縮機吐出圧力
が検知され、その信号が制御装置２０１に入力される。
室内ユニット２，３は、それぞれ、室内熱交換器１２，
１３、室内冷媒流量制御弁２２，２３、室内ファン３
２，３３で構成されている。室外冷媒流量制御弁２１及
び室内冷媒流量制御弁２２，２３の開度は室外ユニット
１内の制御装置２０１によって制御される。室内ユニッ
ト２は建物内の上方階に設置され、室内ユニット３は下
方階に設置されており、室内ユニット２，３間には高低
差がある。室内ユニット２，３と室外ユニット１とはガ
ス配管１２１と液配管１１１で接続されている。下方の
室内ユニット３においては、液配管１１１に液冷媒圧力
検出手段として圧力センサ１７ａが取り付けられてお
り、これにより室内ユニット３の液冷媒圧力が検出でき
るようになっている。圧力センサ１７ａで検出された液
冷媒圧力は室外ユニット１内の制御装置２０１に入力さ
れる。FIG. 1 shows an embodiment of the present invention. This embodiment is a multi-air conditioner for heating only, and its outdoor unit 1 is installed on the roof of a building, and is composed of a compressor 81, an outdoor heat exchanger 11, an outdoor refrigerant flow control valve 21, and an outdoor fan 31. There is. The pressure sensor 1 is provided at the outlet of the compressor 81.
7c is attached to detect the compressor discharge pressure, and the signal is input to the control device 201.
The indoor units 2 and 3 respectively include the indoor heat exchanger 12 and
13, indoor refrigerant flow control valves 22, 23, indoor fan 3
It is composed of 2, 33. The opening degrees of the outdoor refrigerant flow rate control valve 21 and the indoor refrigerant flow rate control valves 22 and 23 are controlled by the control device 201 in the outdoor unit 1. The indoor unit 2 is installed on the upper floor in the building, and the indoor unit 3 is installed on the lower floor, and there is a difference in height between the indoor units 2 and 3. The indoor units 2 and 3 and the outdoor unit 1 are connected by a gas pipe 121 and a liquid pipe 111. In the lower indoor unit 3, a pressure sensor 17a is attached to the liquid pipe 111 as a liquid refrigerant pressure detecting means, so that the liquid refrigerant pressure in the indoor unit 3 can be detected. The liquid refrigerant pressure detected by the pressure sensor 17a is input to the control device 201 in the outdoor unit 1.
【００１９】なお、本実施例では、室内ユニットは２台
であるが、３台以上の室内ユニットが設けられている場
合も構成は上記と同様である。Although the number of indoor units is two in this embodiment, the configuration is the same as above even when three or more indoor units are provided.
【００２０】次に、動作を説明する。圧縮機８１から吐
出された高圧高温の冷媒ガスはガス配管１２１を通って
各室内ユニット２，３に送られ、室内熱交換器１２，１
３で室内ファン２２，２３によって送風された室内空気
と熱交換され、冷媒は凝縮して液冷媒となり、室内空気
は温められ室内が暖房される。この液冷媒は室内ユニッ
ト２，３の室内冷媒流量制御弁２２，２３を通過し、液
配管１１１を通って室外ユニット２へ戻り、室外冷媒流
量制御弁２１で減圧されて室外熱交換器１１へ入り、室
外ファン３１によって送風された室外空気と熱交換さ
れ、冷媒は蒸発して圧縮機８１へ吸入され、再び圧縮さ
れ吐出される。このような動作によって暖房運転が行わ
れる。Next, the operation will be described. The high-pressure and high-temperature refrigerant gas discharged from the compressor 81 is sent to each indoor unit 2, 3 through the gas pipe 121, and the indoor heat exchanger 12, 1
In 3, heat is exchanged with the indoor air blown by the indoor fans 22 and 23, the refrigerant condenses into a liquid refrigerant, the indoor air is warmed, and the room is heated. This liquid refrigerant passes through the indoor refrigerant flow control valves 22 and 23 of the indoor units 2 and 3, returns to the outdoor unit 2 through the liquid pipe 111, is decompressed by the outdoor refrigerant flow control valve 21, and is transferred to the outdoor heat exchanger 11. The heat enters and exchanges heat with the outdoor air blown by the outdoor fan 31, the refrigerant evaporates and is sucked into the compressor 81, and is compressed and discharged again. The heating operation is performed by such an operation.
【００２１】ところで、液配管１１１中には液冷媒が流
れているため、下方の室内ユニット３には上方の室内ユ
ニット２との高低差分の液ヘッドが作用し、室内ユニッ
ト３の冷媒出口での液配管内の圧力は室内ユニット２の
冷媒出口での液配管内の圧力よりも高くなり、室内ユニ
ット２に比較して室内ユニット３には冷媒が流れにくく
なり、室内ユニット３の暖房能力が不足する。これを防
ぐため、本実施例では、例えば、各室内ユニット２，３
の吸い込み空気温度と吹き出し空気温度を不図示の温度
センサで検出して制御装置２０１に入力し、制御装置２
０１でそれらの温度差から各室内ユニットの暖房能力を
求め、室内ユニット３の暖房能力が不足しているときに
は、制御装置２０１は上方の室内ユニット２の冷媒流量
制御弁２２（三台以上の室内ユニットが設置されている
場合は、上方に位置する室内ユニットのうち能力が最大
の室内ユニットの冷媒流量制御弁）の開度を小さくする
ように操作信号を冷媒流量制御弁２２へ送る。これによ
って、冷媒流量制御弁２２は絞られ、該弁２２での圧力
損失が増加し、液配管１１１内の圧力が下がり、これに
より室内ユニット３に冷媒が流れやすくなり、室内ユニ
ット３の暖房能力が確保される。この場合、室内ユニッ
ト３に設置した圧力センサ１７ａで室内ユニット３での
液配管１１１内の圧力が、また、圧力センサ１７ｃで圧
縮機吐出圧力が検出され、それらの信号が制御装置２０
１に入力されており、制御装置２０１は、圧力センサ１
７ａで検出された液配管１１１内圧力が所定圧力、例え
ば、圧力センサ１７ｃで検出された圧縮機吐出圧力より
所定圧力差ΔＰだけ低い圧力、となるように、室内ユニ
ット２の冷媒流量制御弁２２の開度を制御し、もし、上
記圧力センサ１７ａで検出された液配管１１１内の圧力
が上記所定圧力より下がったときは、制御装置２０１
は、室内ユニット２の冷媒流量制御弁２２をそれ以上絞
らない様に制御する。この様な制御により、上方の室内
ユニットの冷媒流量制御弁の絞りすぎによる能力低下を
防止しつつ、各室内ユニットの暖房能力を常に充分確保
することが可能となる。By the way, since the liquid refrigerant flows in the liquid pipe 111, a liquid head having a difference in height from the upper indoor unit 2 acts on the lower indoor unit 3 and the refrigerant outlet of the indoor unit 3 The pressure in the liquid pipe becomes higher than the pressure in the liquid pipe at the refrigerant outlet of the indoor unit 2, the refrigerant does not easily flow to the indoor unit 3 as compared to the indoor unit 2, and the heating capacity of the indoor unit 3 is insufficient. To do. In order to prevent this, in this embodiment, for example, each indoor unit 2, 3
The temperature of the intake air and the temperature of the blown air of the air are detected by a temperature sensor (not shown) and input to the control device 201.
In 01, the heating capacity of each indoor unit is obtained from the temperature difference, and when the heating capacity of the indoor unit 3 is insufficient, the control device 201 controls the refrigerant flow rate control valve 22 of the upper indoor unit 2 (three or more indoor units). When the unit is installed, an operation signal is sent to the refrigerant flow control valve 22 so as to reduce the opening degree of the refrigerant flow control valve of the indoor unit having the maximum capacity among the indoor units located above. As a result, the refrigerant flow control valve 22 is throttled, the pressure loss in the valve 22 increases, and the pressure in the liquid pipe 111 decreases, whereby the refrigerant easily flows into the indoor unit 3 and the heating capacity of the indoor unit 3 increases. Is secured. In this case, the pressure in the liquid pipe 111 in the indoor unit 3 is detected by the pressure sensor 17a installed in the indoor unit 3, and the compressor discharge pressure is detected by the pressure sensor 17c, and these signals are sent to the controller 20.
1 is input to the control device 201,
The refrigerant flow rate control valve 22 of the indoor unit 2 is set so that the internal pressure of the liquid pipe 111 detected by 7a becomes a predetermined pressure, for example, a pressure lower than the compressor discharge pressure detected by the pressure sensor 17c by a predetermined pressure difference ΔP. The opening degree of the control device 201 is controlled, and if the pressure in the liquid pipe 111 detected by the pressure sensor 17a falls below the predetermined pressure, the control device 201
Controls the refrigerant flow rate control valve 22 of the indoor unit 2 so as not to throttle it further. By such control, it becomes possible to always ensure a sufficient heating capacity of each indoor unit while preventing a decrease in capacity due to excessive restriction of the refrigerant flow rate control valve of the upper indoor unit.
【００２２】本発明の他の実施例を図２に示す。本実施
例は複数の室内ユニットの冷房運転または暖房運転のい
ずれかに切換可能なマルチ空調機であり、室外ユニット
１には四方弁６１が取り付けられており、冷房運転と暖
房運転が切り換えられるようになっている。圧縮機８１
の吐出側配管には圧力センサ１７ｃが取り付けられてい
る。また、室外ユニット１内には液配管１１１に圧力セ
ンサ１７ｂが取り付けられ、室内ユニット３には液配管
１１１に圧力センサ１７ａが取り付けられている。他の
構成は図１と同様であり、室内ユニット２が室内ユニッ
ト３より高い所にあることも図１と同様である。Another embodiment of the present invention is shown in FIG. The present embodiment is a multi air conditioner capable of switching between cooling operation and heating operation of a plurality of indoor units, and a four-way valve 61 is attached to the outdoor unit 1 so that the cooling operation and the heating operation can be switched. It has become. Compressor 81
A pressure sensor 17c is attached to the discharge side pipe. A pressure sensor 17b is attached to the liquid pipe 111 inside the outdoor unit 1, and a pressure sensor 17a is attached to the liquid pipe 111 inside the indoor unit 3. Other configurations are the same as in FIG. 1, and the indoor unit 2 is higher than the indoor unit 3 in the same manner as in FIG.
【００２３】暖房運転時には、冷媒が実線矢印で示す流
れとなるように、四方弁６１が切り換えられる。これに
より、冷媒の流れは図１の場合と同様になり、暖房運転
が行われる。この暖房運転時における室内ユニット間の
高低差分の液ヘッドに因る問題、および、それに対処す
るための制御は、図１の実施例で述べたのと同様であ
る。室内ユニット３での液配管１１１内の圧力は、液配
管１１１の高低差と圧力損失を考慮すれば、室外ユニッ
ト１に取り付けた圧力センサ１７ｂで検出した圧力から
求めることができるので、これを用いれば、圧力センサ
１７ａは必ずしも必要でなく、コストダウンのためにこ
れを省いてもよい。なお、図１に示した実施例において
も、これと同様の考えに基づき、圧力センサ１７ａの代
りに図２に示した様に室外ユニット内の液配管圧力セン
サ１７ｂを設け、この圧力センサ１７ｂの検出圧力を用
いて前述と同様の制御を行うようにすることによっても
その目的を達し得る。During the heating operation, the four-way valve 61 is switched so that the refrigerant has a flow indicated by a solid arrow. As a result, the flow of the refrigerant becomes the same as in the case of FIG. 1, and the heating operation is performed. The problem caused by the liquid head having the difference in height between the indoor units during the heating operation and the control for coping with the problem are the same as those described in the embodiment of FIG. The pressure in the liquid pipe 111 in the indoor unit 3 can be obtained from the pressure detected by the pressure sensor 17b attached to the outdoor unit 1 in consideration of the height difference of the liquid pipe 111 and the pressure loss. For example, the pressure sensor 17a is not always necessary and may be omitted for cost reduction. In the embodiment shown in FIG. 1 as well, based on the same idea, a liquid pipe pressure sensor 17b in the outdoor unit is provided as shown in FIG. 2 instead of the pressure sensor 17a, and the pressure sensor 17b The purpose can also be achieved by performing the same control as described above using the detected pressure.
【００２４】次に、冷房運転について説明する。四方弁
６１は冷媒が破線矢印で示す流れとなるように切り換え
られる。圧縮機から吐出された冷媒ガスは、室外熱交換
器１１で室外ファン３１で送風された室外空気と熱交換
され、凝縮して液冷媒となり、室外冷媒流量制御弁２
１、液配管１１１を通って、各室内ユニット２，３へ入
る。各室内ユニット２，３では室内冷媒流量制御弁２
２，２３で液冷媒が減圧され、室内熱交換器１２，１３
へ入る。室内交換器１２，１３へ入った冷媒は、室内フ
ァンによって送風された室内空気と熱交換され蒸発す
る。これにより、室内空気は冷却され、室内が冷房され
る。蒸発した冷媒はガス配管１２１を通って、室外ユニ
ット１へ戻り、圧縮機８１に吸入され、再び圧縮され吐
出される。Next, the cooling operation will be described. The four-way valve 61 is switched so that the refrigerant has a flow indicated by a dashed arrow. The refrigerant gas discharged from the compressor is heat-exchanged with the outdoor air blown by the outdoor fan 31 in the outdoor heat exchanger 11, condensed and becomes a liquid refrigerant, and the outdoor refrigerant flow control valve 2
1. Enter each indoor unit 2, 3 through the liquid pipe 111. In each indoor unit 2 and 3, the indoor refrigerant flow control valve 2
The liquid refrigerant is decompressed by 2, 23, and the indoor heat exchangers 12, 13
Enter The refrigerant entering the indoor exchangers 12 and 13 is heat-exchanged with the indoor air blown by the indoor fan and evaporated. Thereby, the indoor air is cooled and the room is cooled. The evaporated refrigerant returns to the outdoor unit 1 through the gas pipe 121, is sucked into the compressor 81, is compressed again, and is discharged.
【００２５】この冷房運転時に、外気温度が低いとき
は、室外熱交換器１１での凝縮能力が大きくなるため、
圧縮機の吐出圧力が下がり、それに伴なって、吸入圧力
も下がり、室内熱交換器１２，１３内の蒸発圧力も低下
し、これによって、例えば、室内熱交換器１２，１３が
冷えすぎてその空気側に霜が付着し通風抵抗が大きくな
って冷房ができなくなるといった事態が起こる恐れがあ
る。そこで、外気温度が低いとき、室外熱交換器の凝縮
能力が高くなることに伴う圧縮機吐出圧力の低下を防ぐ
ために、室外冷媒流量制御弁２１の開度を制御装置２０
１によって絞り、圧縮機吐出圧力が所定値または所定範
囲になるように制御する。この場合、液配管１１１内の
圧力も圧力センサ１７ｂで検出し、該圧力センサ１７ｂ
で検出される液冷媒圧力が所定圧力、例えば、圧力セン
サ１７ｃで検出された圧縮機吐出圧力より所定圧力差Δ
Ｐだけ低い圧力、より下ったときは、制御装置２０１は
室外冷媒流量制御弁２１を絞らないか、または、所定開
度だけ開く制御を行う。これにより、室外冷媒流量制御
弁２１の絞りすぎによる液配管１１１内の圧力の異常低
下が起こらない様にする。During this cooling operation, when the outside air temperature is low, the condensing capacity of the outdoor heat exchanger 11 becomes large.
The discharge pressure of the compressor is reduced, and the suction pressure is also reduced accordingly, and the evaporation pressure in the indoor heat exchangers 12, 13 is also reduced. As a result, for example, the indoor heat exchangers 12, 13 are too cold and Frost may adhere to the air side to increase ventilation resistance, which may prevent cooling. Therefore, when the outside air temperature is low, the opening degree of the outdoor refrigerant flow control valve 21 is set to the control device 20 in order to prevent a decrease in the compressor discharge pressure due to an increase in the condensation capacity of the outdoor heat exchanger.
The throttle valve is controlled by 1 so that the discharge pressure of the compressor is controlled to a predetermined value or a predetermined range. In this case, the pressure in the liquid pipe 111 is also detected by the pressure sensor 17b, and the pressure sensor 17b
The liquid refrigerant pressure detected at is a predetermined pressure, for example, a predetermined pressure difference Δ from the compressor discharge pressure detected by the pressure sensor 17c.
When the pressure is lower by P or lower, the control device 201 performs control such that the outdoor refrigerant flow control valve 21 is not throttled or is opened by a predetermined opening degree. This prevents the abnormal decrease in the pressure in the liquid pipe 111 due to the excessive restriction of the outdoor refrigerant flow control valve 21.
【００２６】本実施例においては、以上述べた制御によ
り、暖房運転の場合には、図１の実施例の場合と同様の
作用効果が奏せられ、また、冷媒運転の場合には、外気
温が低いときに、室外熱交換器の凝縮能力の増大に伴う
圧縮機吐出圧力の低下を防止すると共に、室外流量制御
弁２１の絞りすぎによる液配管１１１内の圧力の異常低
下、ひいては、圧縮機の吸入圧力および吐出圧力の異常
低下を防止する作用効果が奏せられる。In the present embodiment, the above-described control provides the same operational effects as in the embodiment of FIG. 1 in the heating operation, and in the refrigerant operation in the outside temperature. When the value is low, the compressor discharge pressure is prevented from lowering due to the increase in the condensing capacity of the outdoor heat exchanger, and the pressure in the liquid pipe 111 is abnormally lowered due to the excessive throttle of the outdoor flow control valve 21, and thus the compressor. The action and effect of preventing an abnormal decrease in the suction pressure and the discharge pressure of the are obtained.
【００２７】本発明のさらに他の実施例を図３に示す。
本実施例は、複数の室内ユニットの冷房運転、暖房運
転、または、或る室内ユニットを冷房運転しつつ他の室
内ユニットを暖房運転する所謂冷暖房同時運転、のいず
れにも切換え可能なマルチ空気調和機に関するものであ
るが、図３は室内ユニット２が冷房、室内ユニット３，
４が暖房される冷暖房同時運転状態を示している。室外
ユニット１の圧縮機８１の吐出側は２つの四方弁６１
ａ，６１ｂに接続されている。四方弁６１ａは、圧縮機
８１の吐出側と室外熱交換器１１ａの一端を連通し、圧
縮機８１の吸入側とガス配管１２１を逆止弁７１を介し
て接続するように切換えられている。四方弁６１ｂは、
圧縮機８１の吐出側とガス配管１２１の一端を連通し、
圧縮機８１の吸入側と室外熱交換器１１ｂの一端を連通
するように切換えられている。圧縮機８１の吸入側には
アキュムレータ９１が取り付けられている。室外熱交換
器１１ａ，１１ｂの他端にはそれぞれ室外冷媒流量制御
弁２１ａ，２１ｂの一端が接続され、室外冷媒制御弁２
１ａ，２１ｂの他端同志は結合され、さらに、レシーバ
１０１に接続されている。レシーバ１０１には室内ユニ
ットにつながる液配管１１１の一端が接続されている。
室外冷媒流量制御弁２１ａ，２１ｂの他端同志の結合部
からレシーバ１０１までの液配管と、圧縮機８１の吸入
側とは、液冷媒流量制御弁１４１を介装した液バイパス
回路１５１で接続されている。また、前記液バイパス回
路１４１の液配管側の接続部からレシーバ１０１までの
液配管と、圧縮機８１の吐出側とは、流路の開度が可変
調整できるバイパス流量調整手段（本実施例では流量調
整弁）１６を介装したバイパス回路１７１で接続されて
いる。圧縮機８１の吐出側配管には圧力センサ１７ｃ
が、また、液配管１１１には圧力センサ１７ｂが取り付
けられている。Still another embodiment of the present invention is shown in FIG.
The present embodiment is a multi-air conditioner capable of switching between cooling operation and heating operation of a plurality of indoor units, or so-called simultaneous cooling and heating operation in which a certain indoor unit is cooled and operated while heating another indoor unit. As for the machine, in FIG. 3, the indoor unit 2 is for cooling, the indoor unit 3,
4 shows the simultaneous heating / cooling operation state. The discharge side of the compressor 81 of the outdoor unit 1 has two four-way valves 61.
a, 61b. The four-way valve 61a is switched so that the discharge side of the compressor 81 communicates with one end of the outdoor heat exchanger 11a, and the suction side of the compressor 81 and the gas pipe 121 are connected via the check valve 71. The four-way valve 61b is
The discharge side of the compressor 81 communicates with one end of the gas pipe 121,
The suction side of the compressor 81 and one end of the outdoor heat exchanger 11b are switched to communicate with each other. An accumulator 91 is attached to the suction side of the compressor 81. The other ends of the outdoor heat exchangers 11a and 11b are connected to one ends of the outdoor refrigerant flow control valves 21a and 21b, respectively.
The other ends of 1a and 21b are connected to each other and further connected to the receiver 101. One end of a liquid pipe 111 connected to the indoor unit is connected to the receiver 101.
The liquid piping from the joint between the other ends of the outdoor refrigerant flow control valves 21a and 21b to the receiver 101 and the suction side of the compressor 81 are connected by a liquid bypass circuit 151 having the liquid refrigerant flow control valve 141 interposed. ing. In addition, the liquid pipe from the liquid pipe side connection portion of the liquid bypass circuit 141 to the receiver 101 and the discharge side of the compressor 81 have a bypass flow rate adjusting means (in this embodiment, a variable opening degree of the flow path). They are connected by a bypass circuit 171 having a flow rate adjusting valve 16 interposed therebetween. A pressure sensor 17c is provided on the discharge side pipe of the compressor 81.
However, a pressure sensor 17b is attached to the liquid pipe 111.
【００２８】液配管１１１の他端は室内ユニット２，
３，４の一端に接続されている。ガス配管１２１の他端
は、室内ユニット３，４の他端に接続されている。室内
ユニット２の他端は低圧ガス配管１３１の一端に接続さ
れており、低圧ガス配管１３１の他端は圧縮機８１の吸
入側に接続されている。室内ユニット２，３，４は、夫
々、室内熱交換器１２，１３および１４、液配管１１１
側に取り付けられた室内冷媒流量制御弁２２，２３およ
び２４、ならびに室内ファン３２，３３および３４で構
成されている。なお、室内ユニット２，３，４は室外ユ
ニット１よりも下方にあるとする。The other end of the liquid pipe 111 is connected to the indoor unit 2,
It is connected to one end of 3, 4. The other end of the gas pipe 121 is connected to the other ends of the indoor units 3 and 4. The other end of the indoor unit 2 is connected to one end of the low pressure gas pipe 131, and the other end of the low pressure gas pipe 131 is connected to the suction side of the compressor 81. The indoor units 2, 3 and 4 respectively include the indoor heat exchangers 12, 13 and 14 and the liquid pipe 111.
The indoor refrigerant flow control valves 22, 23 and 24 mounted on the side, and the indoor fans 32, 33 and 34. It is assumed that the indoor units 2, 3, 4 are below the outdoor unit 1.
【００２９】次に、動作について説明する。圧縮機８１
から吐出された吐出ガス冷媒の一部は四方弁６１ａを通
って室外熱交換器１１ａへ入り、室外ファン３１で送ら
れてきた室外空気と熱交換され、凝縮して液冷媒とな
り、室外冷媒流量制御弁２１ａを通って、レシーバ１０
１へ入る。このとき、一部の液冷媒は液バイパス回路１
５１を通って圧縮機８１の吸入側へ送られ、圧縮機８１
の吐出ガス温度制御に利用される。この液冷媒の流量制
御は液冷媒流量制御弁１４１で行われる。レシーバ１０
１へ入った液冷媒は液配管１１１を通って室内ユニット
２へ送られる。圧縮機８１から吐出された吐出ガス冷媒
の他部は、四方弁６１ｂを通ってガス配管１２１へ入
り、室内ユニット３，４へ送られる。室内ユニット３，
４へ入った吐出ガス冷媒は、室内熱交換器１３，１４で
室内ファン３３，３４によって送られてきた夫々の室内
空気と熱交換され、凝縮して液冷媒となる。これによ
り、室内ユニット３，４の存在する室内の空気は温めら
れ、当該それぞれの室内が暖房される。凝縮した液冷媒
は、室内冷媒流量制御弁２３，２４を通って液配管１１
１へ入り、室外ユニット１から送られてきた液冷媒と合
流して、室内ユニット２へ入る。室内ユニット２へ入っ
た液冷媒は室内冷媒流量制御弁２２で減圧されて室内熱
交換器１２へ入り、室内ファン３２によって送られてき
た室内空気と熱交換され、蒸発する。これにより、室内
ユニット２の存在する室内の空気は冷却され、当該室内
が冷房される。室内熱交換器１２で蒸発した冷媒は低圧
ガス配管１３１、アキュムレータ９１を通って圧縮機８
１に吸入される。Next, the operation will be described. Compressor 81
A part of the discharged gas refrigerant discharged from the air flows into the outdoor heat exchanger 11a through the four-way valve 61a, is heat-exchanged with the outdoor air sent by the outdoor fan 31, and is condensed to become the liquid refrigerant. The receiver 10 passes through the control valve 21a.
Enter 1. At this time, part of the liquid refrigerant is in the liquid bypass circuit 1
And is sent to the suction side of the compressor 81 through the compressor 51.
It is used to control the temperature of the discharged gas. The flow control of the liquid refrigerant is performed by the liquid refrigerant flow control valve 141. Receiver 10
The liquid refrigerant entering 1 is sent to the indoor unit 2 through the liquid pipe 111. The other part of the discharged gas refrigerant discharged from the compressor 81 passes through the four-way valve 61b, enters the gas pipe 121, and is sent to the indoor units 3 and 4. Indoor unit 3,
The discharged gas refrigerant that has entered 4 is heat-exchanged with the indoor air sent by the indoor fans 33 and 34 in the indoor heat exchangers 13 and 14, and is condensed to become a liquid refrigerant. As a result, the air in the room where the indoor units 3 and 4 are present is warmed, and the respective rooms are heated. The condensed liquid refrigerant passes through the indoor refrigerant flow control valves 23, 24 and the liquid pipe 11
1 and joins the liquid refrigerant sent from the outdoor unit 1 to enter the indoor unit 2. The liquid refrigerant that has entered the indoor unit 2 is decompressed by the indoor refrigerant flow control valve 22 and enters the indoor heat exchanger 12, where it is heat-exchanged with the indoor air sent by the indoor fan 32 and evaporated. As a result, the air in the room where the indoor unit 2 exists is cooled, and the room is cooled. The refrigerant evaporated in the indoor heat exchanger 12 passes through the low pressure gas pipe 131 and the accumulator 91, and then the compressor 8
Inhaled to 1.
【００３０】この冷暖房同時運転において、外気温度が
低いときには、凝縮器としての室外熱交換器１１ａの凝
縮能力が高まることに伴う圧縮機吐出圧力の低下を防ぐ
ために、バイパス流量制御弁１６を開いて圧縮機吐出ガ
スの一部をバイパス回路１７１を通してレシーバ１０１
の入口に導くことによりレシーバ１０１内の液冷媒を室
外熱交換器１１ａに移動させ、室外熱交換器１１ａを部
分的に液冷媒で埋めて、その有効伝熱面積を減少させて
凝縮能力を減らし、これにより、圧縮機吐出圧力の低下
を防止する。この場合、圧縮機吐出圧力は圧力センサ１
７ｃで検出され、制御装置２０１に入力され、制御装置
２０１は圧縮機吐出圧力が所定値となるように室外冷媒
流量制御弁２１ａを制御する（つまり、圧縮機吐出圧力
が所定値より低いときは室外冷媒流量制御弁２１ａを閉
じる方向に、また高いときは開く方向に制御する）。ま
た、この場合、本実施例においては、液配管１１１内の
圧力も圧力センサ１７ｂで検出され制御装置２０１に入
力され、制御装置２０１は、液配管１１１内の圧力が暖
房中の室内ユニット３，４に所要量の冷媒を流すのに必
要な所定圧力となるようにバイパス流量調整手段１６を
制御する。すなわち、液配管１１１内の圧力が該所定圧
力より低いときはバイパス流量調整手段１６の開度を開
く方向に、また、高いときは閉じる方向に制御する。こ
れによって、暖房室内ユニットに作用する液冷媒ヘッド
の圧力分だけ液配管１１１内の圧力を下げることがで
き、液ヘッドによって生じる暖房室内ユニットの暖房能
力の低下を解消できる。In this simultaneous cooling and heating operation, when the outside air temperature is low, the bypass flow control valve 16 is opened in order to prevent the compressor discharge pressure from decreasing due to the increase in the condensing capacity of the outdoor heat exchanger 11a as a condenser. A part of the compressor discharge gas is passed through the bypass circuit 171 to the receiver 101.
The liquid refrigerant in the receiver 101 is moved to the outdoor heat exchanger 11a by being guided to the inlet of the, and the outdoor heat exchanger 11a is partially filled with the liquid refrigerant to reduce the effective heat transfer area and reduce the condensation capacity. This prevents the compressor discharge pressure from decreasing. In this case, the compressor discharge pressure is measured by the pressure sensor 1.
7c and is input to the control device 201, and the control device 201 controls the outdoor refrigerant flow control valve 21a so that the compressor discharge pressure becomes a predetermined value (that is, when the compressor discharge pressure is lower than the predetermined value. The outdoor refrigerant flow rate control valve 21a is controlled in the closing direction, and when it is high, the opening direction is controlled). Further, in this case, in this embodiment, the pressure in the liquid pipe 111 is also detected by the pressure sensor 17b and input to the control device 201, and the control device 201 controls the indoor unit 3, during which the pressure in the liquid pipe 111 is being heated. The bypass flow rate adjusting means 16 is controlled so that the pressure becomes a predetermined pressure required to flow a required amount of the refrigerant to the valve 4. That is, when the pressure in the liquid pipe 111 is lower than the predetermined pressure, the opening degree of the bypass flow rate adjusting means 16 is controlled to open, and when it is higher, the control is controlled to close. As a result, the pressure in the liquid pipe 111 can be reduced by the pressure of the liquid refrigerant head acting on the heating indoor unit, and the decrease in the heating capacity of the heating indoor unit caused by the liquid head can be eliminated.
【００３１】以上の様な制御により、室外熱交換器を凝
縮器とする冷暖房同時運転において、外気温度が低いと
き、室外熱交換器の凝縮能力が大きくなることに伴う圧
縮機吐出圧力の低下を防止しつつ、暖房室内ユニットに
能力不足が生じることを防止できる。By the control as described above, in the simultaneous cooling and heating operation using the outdoor heat exchanger as the condenser, when the outside air temperature is low, the compressor discharge pressure is reduced due to the increase in the condensation capacity of the outdoor heat exchanger. It is possible to prevent the heating indoor unit from having insufficient capacity while preventing it.
【００３２】本発明のさらに他の実施例を図４に示す。
この実施例の空調機は、液配管内の冷媒を気液二相流に
して冷凍サイクルの封入冷媒量の節減を図った空調機で
ある。図４は、図２に示す実施例から室内ユニット３を
取り除き、室内ユニットを一台としたものに相当する空
気調和機を示している。室外ユニット１と室内ユニット
２の構成は図２と同様である。なお、本実施例では、室
外ユニット１の室外熱交換器１１と室外冷媒流量制御弁
２１との間の配管には、温度センサ４１が取り付けられ
ていて、そこを流れる冷媒温度が検出され、その温度が
制御装置２０１に入力されるようになっている。また、
室内ユニット２の室内熱交換器１２と室内冷媒流量制御
弁２２との間の配管には、温度センサ４２が取り付けら
れており、そこを流れる冷媒温度が検出され、その温度
も制御装置２０１に入力されるようになっている。Yet another embodiment of the present invention is shown in FIG.
The air conditioner of this embodiment is an air conditioner in which the refrigerant in the liquid pipe is made into a gas-liquid two-phase flow to reduce the amount of refrigerant enclosed in the refrigeration cycle. FIG. 4 shows an air conditioner corresponding to one in which the indoor unit 3 is removed from the embodiment shown in FIG. The configurations of the outdoor unit 1 and the indoor unit 2 are the same as in FIG. In this embodiment, a temperature sensor 41 is attached to the pipe between the outdoor heat exchanger 11 of the outdoor unit 1 and the outdoor refrigerant flow control valve 21, and the temperature of the refrigerant flowing therethrough is detected. The temperature is input to the control device 201. Also,
A temperature sensor 42 is attached to a pipe between the indoor heat exchanger 12 of the indoor unit 2 and the indoor refrigerant flow control valve 22, the temperature of the refrigerant flowing therethrough is detected, and the temperature is also input to the control device 201. It is supposed to be done.
【００３３】次に、この実施例の動作について説明す
る。Next, the operation of this embodiment will be described.
【００３４】冷房運転の場合、冷媒は破線矢印で示す流
れとなり、室外熱交換器１１は凝縮器、室内熱交換器１
２は蒸発器として働く。なお、冷房運転での冷媒の状態
を図５のモリエル線図で示す。圧縮機８１を出た圧力Ｐ
ｄ、温度Ｔｄの冷媒は四方弁６１を通って室外熱交換器
１１へ入り、室外空気と熱交換されて、室外熱交換器１
１の出口では圧力Ｐｃ、温度Ｔｃの液冷媒となる。室外
熱交換器１１出口の冷媒温度Ｔｃは温度センサ４１で検
知され、制御装置２０１へ入力される。室外熱交換器１
１を出た冷媒は室外冷媒流量制御弁２１で減圧されて該
弁２１の出口では圧力Ｐ２、温度Ｔ２の冷媒となり、液
配管１１１へ入る。該弁２１の出口すなわち液配管１１
１の入口の圧力Ｐ２は圧力センサ１７ｂで検知され、制
御装置２０１へ入力される。制御装置２０１では、温度
センサ４１で検知した室外熱交換器１１出口の冷媒温度
Ｔｃから、室外熱交換器１１出口の飽和圧力Ｐ１を算出
し、液配管１１１入口の圧力Ｐ２が、前記飽和圧力Ｐ１
より低く、かつ、室内ユニットの蒸発器１２の目標蒸発
圧力Ｐ４０（後記の蒸発圧力Ｐ４の目標値）に液配管１
１１での圧力損失分ΔＰＬを加えた圧力以上の設定圧力
となるように、室外冷媒流量制御弁２１を制御する。こ
こで、目標蒸発圧力Ｐ４０は蒸発器１２の凍結温度の飽
和圧力より高い圧力に設定する。液配管１１１での圧力
損失分ΔＰＬは、配管長から推定できる。液配管１１１
を出た圧力Ｐ３（＝Ｐ２−ΔＰＬ）、温度Ｔ３の冷媒は
室内ユニット２へ入り、室内冷媒流量制御弁２２で減圧
されて圧力Ｐ４、温度Ｔ４の冷媒となり、室内熱交換器
１２に入る。室内熱交換器１２に入った冷媒は室内空気
と熱交換されて蒸発し、空気は冷却される。室内熱交換
器１２入口の冷媒の温度Ｔ４は温度センサ４２で検知さ
れ、制御装置２０１へ入力されている。また、図には示
されていないが、室内熱交換器１２出口の冷媒温度また
は圧縮機吐出ガス温度Ｔｄも検知され制御装置２０１に
入力されている。制御装置２０１は、室内熱交換器１２
出口の温度または圧縮機吐出ガス温度Ｔｄが所定の温度
になるように、また、室内熱交換器１２入口の冷媒の温
度Ｔ４が凍結温度以上となるように、室内冷媒流量制御
弁２２を制御する。室内熱交換器１２で蒸発した冷媒
は、ガス配管１２１を通って室外ユニット１へ入り、四
方弁６１を通って、圧力Ｐｓ、温度Ｔｓの冷媒となり、
圧縮機８１に吸入される。In the cooling operation, the refrigerant flows as indicated by the broken line arrow, and the outdoor heat exchanger 11 is the condenser and the indoor heat exchanger 1
2 acts as an evaporator. The state of the refrigerant during the cooling operation is shown in the Mollier diagram of FIG. Pressure P exiting the compressor 81
The refrigerant having the temperature d and the temperature Td enters the outdoor heat exchanger 11 through the four-way valve 61 and is heat-exchanged with the outdoor air to generate the outdoor heat exchanger 1.
At the outlet of No. 1, the liquid refrigerant has a pressure Pc and a temperature Tc. The temperature Tc of the refrigerant at the outlet of the outdoor heat exchanger 11 is detected by the temperature sensor 41 and input to the control device 201. Outdoor heat exchanger 1
The refrigerant discharged from No. 1 is decompressed by the outdoor refrigerant flow control valve 21, becomes a refrigerant of pressure P2 and temperature T2 at the outlet of the valve 21, and enters the liquid pipe 111. The outlet of the valve 21, that is, the liquid pipe 11
The pressure P2 at the inlet of 1 is detected by the pressure sensor 17b and input to the control device 201. In the control device 201, the saturation pressure P1 at the outlet of the outdoor heat exchanger 11 is calculated from the refrigerant temperature Tc at the outlet of the outdoor heat exchanger 11 detected by the temperature sensor 41, and the pressure P2 at the inlet of the liquid pipe 111 is the saturation pressure P1.
The liquid pipe 1 is lower than the target evaporation pressure P40 of the evaporator 12 of the indoor unit (the target value of the evaporation pressure P4 described later).
The outdoor refrigerant flow control valve 21 is controlled so that the set pressure becomes equal to or higher than the pressure to which the pressure loss ΔPL at 11 is added. Here, the target evaporation pressure P40 is set to a pressure higher than the saturation pressure of the freezing temperature of the evaporator 12. The pressure loss amount ΔPL in the liquid pipe 111 can be estimated from the pipe length. Liquid piping 111
The refrigerant having the pressure P3 (= P2−ΔPL) and the temperature T3, which has exited, enters the indoor unit 2, is decompressed by the indoor refrigerant flow control valve 22 to become the refrigerant having the pressure P4 and the temperature T4, and enters the indoor heat exchanger 12. The refrigerant having entered the indoor heat exchanger 12 is heat-exchanged with the indoor air to evaporate, and the air is cooled. The temperature T4 of the refrigerant at the inlet of the indoor heat exchanger 12 is detected by the temperature sensor 42 and input to the control device 201. Although not shown in the figure, the refrigerant temperature at the outlet of the indoor heat exchanger 12 or the compressor discharge gas temperature Td is also detected and input to the control device 201. The control device 201 uses the indoor heat exchanger 12
The indoor refrigerant flow rate control valve 22 is controlled so that the outlet temperature or the compressor discharge gas temperature Td becomes a predetermined temperature, and the refrigerant temperature T4 at the inlet of the indoor heat exchanger 12 becomes the freezing temperature or higher. .. The refrigerant evaporated in the indoor heat exchanger 12 enters the outdoor unit 1 through the gas pipe 121, passes through the four-way valve 61, and becomes the refrigerant of pressure Ps and temperature Ts,
It is sucked into the compressor 81.
【００３５】暖房運転の場合、冷媒は実線矢印で示す流
れとなり、室外熱交換器１１は蒸発器、室内熱交換器１
２は凝縮器として働く。圧縮機８１を出た冷媒は四方弁
６１を通り、さらにガス配管１２１を通って、室内ユニ
ット２へ入る。室内ユニット２へ入った冷媒は、室内熱
交換器１２で室内空気と熱交換されて液冷媒となり、室
内冷媒制御弁２２で減圧されて液配管１１１に入り、さ
らに室外ユニット１へ入る。室内熱交換器１２を出た液
冷媒の温度は温度センサ４２で検知され、制御装置２０
１に入力される。また、液配管１１１出口の圧力センサ
１７ｂで検出され制御装置２０１に入力される。制御装
置２０１は、圧力センサ１７ｂで検出された液配管１１
１出口の圧力が所定圧力となるように室内冷媒制御弁２
２を制御する。ここで、所定圧力は、液配管１１１内の
冷媒が気液二相流となる圧力で、冷媒飽和温度が外気温
度程度となるような圧力とする。室外ユニット１に入っ
た冷媒は、室外冷媒流量制御弁２１で減圧され、室外熱
交換器１１へ入り、室外空気と熱交換されて蒸発し、四
方弁６１を通って圧縮機８１に吸入される。室外冷媒流
量制御弁２１は、室外熱交換器出口温度または圧縮機吐
出温度が所定温度となるように、制御装置２０１で制御
される。In the heating operation, the refrigerant flows as shown by the solid arrow, and the outdoor heat exchanger 11 is the evaporator and the indoor heat exchanger 1.
2 acts as a condenser. The refrigerant exiting the compressor 81 passes through the four-way valve 61, further passes through the gas pipe 121, and enters the indoor unit 2. The refrigerant that has entered the indoor unit 2 is heat-exchanged with indoor air in the indoor heat exchanger 12 to become a liquid refrigerant, is decompressed by the indoor refrigerant control valve 22, enters the liquid pipe 111, and further enters the outdoor unit 1. The temperature of the liquid refrigerant that has exited the indoor heat exchanger 12 is detected by the temperature sensor 42, and the control device 20
Input to 1. Further, it is detected by the pressure sensor 17b at the outlet of the liquid pipe 111 and input to the control device 201. The control device 201 uses the liquid pipe 11 detected by the pressure sensor 17b.
1 Indoor refrigerant control valve 2 so that the pressure at the outlet becomes a predetermined pressure
Control 2 Here, the predetermined pressure is a pressure at which the refrigerant in the liquid pipe 111 becomes a gas-liquid two-phase flow, and is a pressure at which the refrigerant saturation temperature becomes about the outside air temperature. The refrigerant that has entered the outdoor unit 1 is decompressed by the outdoor refrigerant flow control valve 21, enters the outdoor heat exchanger 11, exchanges heat with the outdoor air, evaporates, and is sucked into the compressor 81 through the four-way valve 61. .. The outdoor refrigerant flow control valve 21 is controlled by the control device 201 so that the outdoor heat exchanger outlet temperature or the compressor discharge temperature becomes a predetermined temperature.
【００３６】なお、本実施例において、圧力センサ１７
ｂによる液配管内圧力の検出の代わりに温度センサを用
いて液配管内の冷媒の飽和温度を検出して、その温度か
ら上記圧力を算出してもよい。また、上記液配管内の冷
媒温度が凝縮器出口の冷媒温度より所定値だけ低くなる
ように室外冷媒流量制御弁２１または室内冷媒流量制御
弁２２を制御してもよい。In this embodiment, the pressure sensor 17
Instead of detecting the pressure in the liquid pipe by b, a temperature sensor may be used to detect the saturation temperature of the refrigerant in the liquid pipe, and the pressure may be calculated from the temperature. Further, the outdoor refrigerant flow rate control valve 21 or the indoor refrigerant flow rate control valve 22 may be controlled such that the refrigerant temperature in the liquid pipe is lower than the refrigerant temperature at the condenser outlet by a predetermined value.
【００３７】本実施例では、以上のような制御により、
冷媒封入量節減のため液配管内の冷媒を気液二相流とす
ることが可能であり、しかも、蒸発器での蒸発圧力およ
び圧縮機吸入圧力の下りすぎの防止、ひいては、蒸発器
の凍結防止、冷房運転時の室内ユニットの着霜防止、暖
房運転時の充分な暖房能力の確保が可能になる。In the present embodiment, by the above control,
The refrigerant in the liquid pipe can be made into a gas-liquid two-phase flow in order to save the amount of refrigerant enclosed, and moreover, the evaporation pressure in the evaporator and the compressor suction pressure are prevented from falling too much, and the evaporator is frozen. It is possible to prevent the formation of frost on the indoor unit during the cooling operation and to secure a sufficient heating capacity during the heating operation.
【００３８】図６は、図３に示したバイパス流量調整手
段１６の他の実施例を示す。図６に示したバイパス流量
調整手段１６は、電磁弁１６１ａ，１６１ｂと、径の異
なるキャピラリチューブ１６２ａ，１６２ｂとで構成さ
れ、電磁弁１６１ａと径の細いキャピラリチューブ１６
２ａが直列に接続され、電磁弁１６１ｂと径の太いキャ
ピラリチューブ１６２ｂが直列に接続され、さらに、こ
れらが並列に接続されている。それぞれの電磁弁１６１
ａ，１６１ｂは図３に示した制御装置２０１によって開
閉制御される。次に、動作について説明する。外気温度
が比較的高いとき、電磁弁１６１ａを開き、電磁弁１６
１ｂを閉じる。これによって、図３におけるバイパス回
路１７１を流れる圧縮機吐出ガス流量は少流量となり、
室外熱交換器１１ａに溜る液冷媒量も少量となる。外気
温度が上記より低いとき、電磁弁１６１ａを閉じ、電磁
弁１６１ｂを開く。これによって、前記バイパス回路１
７１を流れる圧縮機吐出ガス流量が増え、室外熱交換器
１１ａに溜る液冷媒量も増加する。外気温度が上記より
さらに低いとき、電磁弁１６１ａおよび１６１ｂを開
く。これによって、前記バイパス回路１７１を流れる圧
縮機吐出ガス流量はさらに増え、室外熱交換器１１ａに
溜る液冷媒量もさらに増加する。このように、外気温度
によって、バイパス回路１７１を流れる圧縮機吐出ガス
流量を変えることにより室外熱交換器１１ａの有効伝熱
面積が制御でき、室外冷媒流量制御弁２１ａの開度をあ
まり変化させずに圧縮機吐出圧力を制御できる。FIG. 6 shows another embodiment of the bypass flow rate adjusting means 16 shown in FIG. The bypass flow rate adjusting means 16 shown in FIG. 6 includes electromagnetic valves 161a and 161b and capillary tubes 162a and 162b having different diameters, and the electromagnetic valve 161a and the capillary tube 16 having a small diameter.
2a are connected in series, a solenoid valve 161b and a capillary tube 162b having a large diameter are connected in series, and further, these are connected in parallel. Each solenoid valve 161
Opening and closing of a and 161b are controlled by the control device 201 shown in FIG. Next, the operation will be described. When the outside air temperature is relatively high, the solenoid valve 161a is opened and the solenoid valve 16
Close 1b. As a result, the compressor discharge gas flow rate flowing through the bypass circuit 171 in FIG.
The amount of liquid refrigerant accumulated in the outdoor heat exchanger 11a also becomes small. When the outside air temperature is lower than the above temperature, the solenoid valve 161a is closed and the solenoid valve 161b is opened. Thereby, the bypass circuit 1
The compressor discharge gas flow rate flowing through 71 increases, and the amount of liquid refrigerant accumulated in the outdoor heat exchanger 11a also increases. When the outside air temperature is lower than the above temperature, the solenoid valves 161a and 161b are opened. As a result, the flow rate of gas discharged from the compressor flowing through the bypass circuit 171 is further increased, and the amount of liquid refrigerant accumulated in the outdoor heat exchanger 11a is further increased. In this way, the effective heat transfer area of the outdoor heat exchanger 11a can be controlled by changing the compressor discharge gas flow rate flowing through the bypass circuit 171 depending on the outside air temperature, and the opening degree of the outdoor refrigerant flow rate control valve 21a does not change so much. The compressor discharge pressure can be controlled.
【００３９】また、図６に示したバイパス流量制御手段
１６は、電磁弁の切り換えによって冷媒流量制御ができ
るので、バイパス流量の制御だけでなく、図１，図２，
図３，図４における室外冷媒流量制御弁２１，２１ａ，
２１ｂや室内冷媒流量制御弁２２，２３，２４としても
使用可能である。Further, since the bypass flow rate control means 16 shown in FIG. 6 can control the refrigerant flow rate by switching the solenoid valve, not only the bypass flow rate control but also FIGS.
The outdoor refrigerant flow control valves 21, 21a in FIGS.
21b and the indoor refrigerant flow control valves 22, 23, 24 can also be used.
【００４０】図７は、図２，図３，図４において室外ユ
ニット１の液冷媒圧力検出手段として取り付けられる圧
力センサ１７ｂに関する他の実施例を示す。圧力センサ
１７ｂは電磁弁１８ａと電磁弁１８ｂの夫々の一端に接
続され、電磁弁１８ａの他端は図２，図３，図４に示し
た液配管１１１に接続されており、電磁弁１８ｂの他端
は圧縮機８１の吸入側または吐出側に接続されている。
したがって、電磁弁１８ａ，１８ｂの切り換えによっ
て、圧力センサ１７ｂは液配管１１１内の圧力を検出し
たり、圧縮機８１の吐出圧力または吸入圧力を検出する
ことができる。これによって図２，図３，図４におい
て、液冷媒圧力検出手段である圧力センサ１７ｂを、圧
縮機の吐出圧力を検出する圧力センサ１７ｃまたは吸入
圧力を検出する圧力センサとして共用でき、コスト低減
になる。FIG. 7 shows another embodiment relating to the pressure sensor 17b mounted as the liquid refrigerant pressure detecting means of the outdoor unit 1 in FIGS. The pressure sensor 17b is connected to one end of each of the solenoid valve 18a and the solenoid valve 18b, and the other end of the solenoid valve 18a is connected to the liquid pipe 111 shown in FIG. 2, FIG. 3, and FIG. The other end is connected to the suction side or the discharge side of the compressor 81.
Therefore, by switching the solenoid valves 18a and 18b, the pressure sensor 17b can detect the pressure in the liquid pipe 111 and the discharge pressure or the suction pressure of the compressor 81. As a result, in FIGS. 2, 3 and 4, the pressure sensor 17b, which is the liquid refrigerant pressure detection means, can be shared as the pressure sensor 17c for detecting the discharge pressure of the compressor or the pressure sensor for detecting the suction pressure, which leads to cost reduction. Become.
【００４１】[0041]
（１）１台の室外ユニットに室内ユニットが複数台接続
されている所謂マルチ空気調和機の暖房運転において、
室内ユニット間に高低差がある場合に、高低差分の液ヘ
ッドを解消し各室内ユニットの暖房能力を確保できる。(1) In the heating operation of a so-called multi-air conditioner in which a plurality of indoor units are connected to one outdoor unit,
When there is a difference in height between the indoor units, it is possible to eliminate the liquid head having the difference in height and secure the heating capacity of each indoor unit.
【００４２】（２）１台の室外ユニットに１台の室内ユ
ニットが接続されている空調機もしくは１台の室外ユニ
ットに複数台の室内ユニットが接続されているマルチ空
調機の冷房運転、又は、マルチ空調機で室外交換器を凝
縮器とする冷暖房同時運転において、外気温度が低いと
き、室外熱交換器の凝縮能力が大きくなることに伴う圧
縮器吐出圧力の低下の防止を室外熱交換器出口の冷媒流
量調整手段を絞ることによって行う場合に、該冷媒流量
調整手段の絞りすぎによる液配管内の圧力、ひいては、
圧縮機の吸入圧力および吐出圧力の異常低下を防止でき
る。(2) Cooling operation of an air conditioner in which one indoor unit is connected to one outdoor unit or a multi air conditioner in which a plurality of indoor units are connected to one outdoor unit, or In simultaneous cooling and heating operation using an outdoor exchanger as a condenser in a multi-air conditioner, when the outside air temperature is low, the decrease in the compressor discharge pressure due to the increase in the condensation capacity of the outdoor heat exchanger is prevented. When the refrigerant flow rate adjusting means is squeezed, the pressure in the liquid pipe due to excessive squeezing of the refrigerant flow rate adjusting means, and by extension,
It is possible to prevent abnormal reduction in the suction pressure and the discharge pressure of the compressor.
【００４３】（３）マルチ空気調和機で室外熱交換機を
凝縮器とする冷暖房同時運転において、外気温度が低い
とき、室外熱交換器の凝縮能力が大きくなることに伴う
圧縮機吐出圧力の低下を防止するために、圧縮機吐出ガ
スの１部をレシーバ入口にバイパスしてレシーバ内の液
冷媒を室外熱交換器に移すことによってその凝縮能力を
制御する場合にも、暖房室内ユニットの暖房能力を確保
できる。(3) In the multi-air conditioner in the simultaneous cooling and heating operation using the outdoor heat exchanger as a condenser, when the outdoor air temperature is low, the compressor discharge pressure is reduced due to the increase in the condensation capacity of the outdoor heat exchanger. To prevent this, even when controlling the condensation capacity by bypassing a part of the compressor discharge gas to the receiver inlet and transferring the liquid refrigerant in the receiver to the outdoor heat exchanger, the heating capacity of the heating indoor unit is also reduced. Can be secured.
【００４４】（４）空気調和機の冷媒封入量を減らすた
めに液配管内の冷媒を気液二相流とする空気調和機にお
いて、蒸発圧力の低下が防止でき、安定した運転ができ
る。(4) In an air conditioner in which the refrigerant in the liquid pipe is in a gas-liquid two-phase flow in order to reduce the amount of refrigerant charged in the air conditioner, the evaporation pressure can be prevented from lowering and stable operation can be performed.
【図１】本発明の一実施例の冷凍サイクル構成図FIG. 1 is a configuration diagram of a refrigeration cycle according to an embodiment of the present invention.
【図２】本発明の他の実施例の冷凍サイクル構成図FIG. 2 is a refrigeration cycle configuration diagram of another embodiment of the present invention.
【図３】本発明のさらに他の実施例の冷凍サイクル構成
図FIG. 3 is a refrigeration cycle configuration diagram of still another embodiment of the present invention.
【図４】本発明のさらに別の実施例の冷凍サイクル構成
図FIG. 4 is a refrigeration cycle configuration diagram of still another embodiment of the present invention.
【図５】図４の実施例における冷凍サイクル内の冷媒状
態を示すモリエル線図5 is a Mollier diagram showing the state of refrigerant in the refrigeration cycle in the embodiment of FIG.
【図６】本発明に用いるバイパス流量調整手段の他の実
施例を示す構成図FIG. 6 is a configuration diagram showing another embodiment of the bypass flow rate adjusting means used in the present invention.
【図７】本発明に用いる液冷媒圧力検出手段に関する他
の実施例を示す構成図FIG. 7 is a configuration diagram showing another embodiment of the liquid refrigerant pressure detection means used in the present invention.
１…室外ユニット ２，３，４…室内
ユニット ２１，２１ａ，２１ｂ…室外冷媒流量制御弁 ２２，２３，２４…室内冷媒流量制御弁 １６…バイパス流量調整手段 １７ａ，１７ｂ，
１７ｃ…圧力センサ １１，１１ａ，１１ｂ…室外熱交換器 １２，１３，１４…室内熱交換器 ４１，４２…温度
センサ ６１，６１ａ，６１ｂ…四方弁 ８１…圧縮機 １１１…液配管 １２１…ガス配管 １３１…低圧ガス配管 １６１ａ，１６１
ｂ…電磁弁 １６２ａ，１６２ｂ…キャピラリチューブ ２０１…制御装置1 ... Outdoor unit 2,3,4 ... Indoor unit 21,21a, 21b ... Outdoor refrigerant flow rate control valve 22,23,24 ... Indoor refrigerant flow rate control valve 16 ... Bypass flow rate adjusting means 17a, 17b,
17c ... Pressure sensor 11, 11a, 11b ... Outdoor heat exchanger 12, 13, 14 ... Indoor heat exchanger 41, 42 ... Temperature sensor 61, 61a, 61b ... Four-way valve 81 ... Compressor 111 ... Liquid pipe 121 ... Gas pipe 131 ... Low-pressure gas piping 161a, 161
b ... Solenoid valves 162a, 162b ... Capillary tube 201 ... Control device
───────────────────────────────────────────────────── フロントページの続き (72)発明者 北條俊幸 静岡県清水市村松390番地 株式会社日立 製作所清水工場内 (72)発明者 竹中 寛 静岡県清水市村松390番地 株式会社日立 製作所清水工場内 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshiyuki Hojo, 390 Muramatsu, Shimizu City, Shizuoka Prefecture, Hitachi Shimizu Plant (72) Inventor, Hiroshi Takenaka, 390, Muramatsu, Shimizu City, Shizuoka Hitachi, Ltd., Shimizu Plant, Ltd.
Claims (6)
構成された室外ユニットと、室内熱交換器及び室内ファ
ンで構成された一台または複数台の室内ユニットとを、
液冷媒が流れる液配管と、高圧ガス冷媒が流れるガス配
管および／または低圧ガス冷媒が流れるガス配管とによ
って接続した空気調和機において、前記液配管内の圧力
を検出する液配管圧力検出手段と、該液配管圧力検出手
段の検出値に基づいて液配管内の圧力を調整する液冷媒
圧力調整手段とを備えたことを特徴とする空気調和機。1. An outdoor unit composed of a compressor, an outdoor heat exchanger and an outdoor fan, and one or a plurality of indoor units composed of an indoor heat exchanger and an indoor fan,
In an air conditioner connected by a liquid pipe through which a liquid refrigerant flows, a gas pipe through which a high-pressure gas refrigerant flows and / or a gas pipe through which a low-pressure gas refrigerant flows, liquid pipe pressure detection means for detecting the pressure in the liquid pipe, An air conditioner comprising: a liquid refrigerant pressure adjusting unit that adjusts the pressure in the liquid pipe based on the detection value of the liquid pipe pressure detecting unit.
がある複数台であり、前記液冷媒圧力調整手段は上方の
室内ユニットの冷媒流量調整手段よりなる請求項１記載
の空気調和機。2. The air conditioner according to claim 1, wherein the indoor units are a plurality of units having height differences between the installation positions, and the liquid refrigerant pressure adjusting means is a refrigerant flow rate adjusting means of the upper indoor unit.
の室外熱交換器出口の冷媒流量調整手段よりなる請求項
１記載の空気調和機。3. The air conditioner according to claim 1, wherein the liquid refrigerant pressure adjusting means comprises a refrigerant flow rate adjusting means at the outdoor heat exchanger outlet of the outdoor unit.
ガス冷媒の一部を室外ユニット中の液配管に設けたレシ
ーバに導くバイパス回路と該バイパス回路の流路抵抗を
調整するバイパス流量調整手段とからなることを特徴と
する請求項１記載の空気調和機。4. A bypass circuit for guiding a part of a compressor discharge gas refrigerant to a receiver provided in a liquid pipe in an outdoor unit, and a bypass flow rate adjusting means for adjusting a flow path resistance of the bypass circuit. The air conditioner according to claim 1, wherein the air conditioner comprises:
出口冷媒温度検出手段を備え、前記液配管圧力検出手段
で検出された液配管内の圧力が、凝縮器出口の冷媒温度
の飽和圧力より低く、且つ、液配管出口圧力が蒸発器の
目標蒸発圧力以上となるように、前記液冷媒圧力調整手
段によって液配管内の圧力を制御することを特徴とする
請求項１記載の空気調和機。5. A condenser outlet refrigerant temperature detecting means for detecting a condenser outlet refrigerant temperature, wherein the pressure in the liquid pipe detected by the liquid pipe pressure detecting means is a saturation pressure of the condenser outlet refrigerant temperature. The air conditioner according to claim 1, wherein the pressure in the liquid pipe is controlled by the liquid refrigerant pressure adjusting means so that the pressure is lower and the liquid pipe outlet pressure is equal to or higher than the target evaporation pressure of the evaporator. ..
冷媒温度検出手段と、凝縮器出口の冷媒温度を検出する
凝縮器出口冷媒温度検出手段とを備え、液配管内の冷媒
温度が凝縮器出口の冷媒温度より所定値だけ低くなるよ
うに前記液冷媒圧力調整手段によって液配管内の圧力を
制御することを特徴とする請求項１記載の空気調和機。6. A refrigerant temperature detecting means in the liquid pipe for detecting a refrigerant temperature in the liquid piping, and a condenser outlet refrigerant temperature detecting means for detecting a refrigerant temperature in the condenser outlet are provided. The air conditioner according to claim 1, wherein the pressure inside the liquid pipe is controlled by the liquid refrigerant pressure adjusting means so as to be lower than the refrigerant temperature at the condenser outlet by a predetermined value.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4139013A JP2968392B2 (en) | 1992-05-29 | 1992-05-29 | Air conditioner |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4139013A JP2968392B2 (en) | 1992-05-29 | 1992-05-29 | Air conditioner |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH05332630A true JPH05332630A (en) | 1993-12-14 |
| JP2968392B2 JP2968392B2 (en) | 1999-10-25 |
Family
ID=15235444
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4139013A Expired - Fee Related JP2968392B2 (en) | 1992-05-29 | 1992-05-29 | Air conditioner |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2968392B2 (en) |
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| CN107683393A (en) * | 2015-06-18 | 2018-02-09 | 大金工业株式会社 | Air-conditioning device |
| AU2016279490B2 (en) * | 2015-06-18 | 2019-01-31 | Daikin Industries, Ltd. | Air conditioner |
| WO2016204194A1 (en) * | 2015-06-18 | 2016-12-22 | ダイキン工業株式会社 | Air conditioner |
| CN107683393B (en) * | 2015-06-18 | 2020-08-04 | 大金工业株式会社 | Air conditioner |
| US11199342B2 (en) | 2015-06-18 | 2021-12-14 | Daikin Industries, Ltd. | Air conditioner |
| CN113439188A (en) * | 2019-02-27 | 2021-09-24 | 三菱电机株式会社 | Air conditioner |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2968392B2 (en) | 1999-10-25 |
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