JP2006112708A - Refrigerating air conditioner - Google Patents

Refrigerating air conditioner Download PDF

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Publication number
JP2006112708A
JP2006112708A JP2004300022A JP2004300022A JP2006112708A JP 2006112708 A JP2006112708 A JP 2006112708A JP 2004300022 A JP2004300022 A JP 2004300022A JP 2004300022 A JP2004300022 A JP 2004300022A JP 2006112708 A JP2006112708 A JP 2006112708A
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refrigerant
heat exchanger
compressor
outlet
indoor heat
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Fumitake Unezaki
史武 畝崎
Makoto Seito
信 齊籐
Tetsuji Nanatane
哲二 七種
Masanori Aoki
正則 青木
Masato Yosomiya
正人 四十宮
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Mitsubishi Electric Corp
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Mitsubishi Electric Corp
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Priority to JP2004300022A priority Critical patent/JP2006112708A/en
Publication of JP2006112708A publication Critical patent/JP2006112708A/en
Priority to US12/760,190 priority patent/US20100192607A1/en
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    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25BREFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2400/00General features or devices for refrigeration machines, plants or systems, combined heating and refrigeration systems or heat-pump systems, i.e. not limited to a particular subgroup of F25B
    • F25B2400/13Economisers

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Abstract

<P>PROBLEM TO BE SOLVED: To enable exhibition of sufficient heating capacity even in a cold district where the outside air temperature is -10°C or lower by improving the heating capacity in a refrigerating air conditioner more than that in a conventional gas injection cycle. <P>SOLUTION: The refrigerating air conditioner includes a compressor 3, an indoor heat exchanger 6, a first decompression device 11, and an outdoor heat exchanger 12, which are circularly connected to supply hot heat from the indoor heat exchanger. This air conditioner further comprises a first internal heat exchanger 9 heat-exchanging the refrigerant between the indoor heat exchanger and the first decompression device with the refrigerant between the outdoor heat exchanger and the compressor; an injection circuit 13 injecting the refrigerant between the indoor heat exchanger and the first decompression device into a compression chamber within the compressor while partially bypassing; an injection decompression device 14 provided in the injection circuit; and a second internal heat exchanger 10 heat-exchanging the refrigerant decompressed by the injection decompression device with the refrigerant between the indoor heat exchanger and the first decompression device. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

この発明は、冷凍空調装置に関するものであり、特にガスインジェクションを行い低外気温度時の暖房能力を向上させる冷凍空調装置に関するものである。   The present invention relates to a refrigeration air conditioner, and more particularly to a refrigeration air conditioner that performs gas injection to improve the heating capacity at a low outside air temperature.

従来の冷凍空調装置として、凝縮器と蒸発器との間の中間圧部分に気液分離器を設け、気液分離器で分離されたガス冷媒を圧縮機の中間圧部分にインジェクションし、暖房能力の向上をもたらすようにしたものがある(例えば、特許文献1参照)。
また、気液分離器の代わりに、高圧液冷媒の一部をバイパスし、減圧した後で高圧液冷媒と熱交換し蒸発ガス化させた後で、圧縮機にインジェクションし暖房能力の向上をもたらすようにしたものがある(例えば、特許文献2参照)。
また、凝縮器と蒸発器との間の中間圧部分に液レシーバを設け、液レシーバ内の冷媒と圧縮機吸入の冷媒を熱交換させる構成としたものがある(例えば、特許文献3参照)。
As a conventional refrigeration air conditioner, a gas-liquid separator is installed at the intermediate pressure part between the condenser and the evaporator, and the gas refrigerant separated by the gas-liquid separator is injected into the intermediate pressure part of the compressor to increase the heating capacity. (For example, refer to Patent Document 1).
Also, instead of the gas-liquid separator, a part of the high-pressure liquid refrigerant is bypassed, and after reducing the pressure, heat exchange with the high-pressure liquid refrigerant is carried out to evaporate gas, and then injected into the compressor to improve the heating capacity. There is something like this (see, for example, Patent Document 2).
In addition, there is a configuration in which a liquid receiver is provided in an intermediate pressure portion between the condenser and the evaporator so that heat is exchanged between the refrigerant in the liquid receiver and the refrigerant sucked by the compressor (for example, see Patent Document 3).

特開2001−304714号公報JP 2001-304714 A 特開2000−274859号公報JP 2000-274859 A 特開2001−174091号公報JP 2001-174091 A

しかし、従来の冷凍空調装置には以下のような問題があった。
まず、特許文献1記載の従来例のように、気液分離器を設けたインジェクションを行う場合、気液分離器内の液量がインジェクション量によって変化し、それに伴い冷凍サイクル内の液冷媒量分布が変動し、運転が不安定になるという問題があった。
インジェクションされるガス冷媒流量と気液分離器に流入する二相冷媒のうちのガス冷媒流量とが釣り合っている場合は、蒸発器側に流出するのは液冷媒のみとなり、気液分離器内の液冷媒量は安定するが、インジェクションされる冷媒流量が減少し、その冷媒流量が気液分離器に流入するガス冷媒流量より少なくなると、蒸発器側にガス冷媒も流出する運転となり、気液分離器底部からガスが流出するために、気液分離器内の液はほとんど流出した運転となる。
逆に、インジェクションされる冷媒流量が増加すると、ガス冷媒が足りないため、ガス冷媒に混じって液冷媒もインジェクションされる状態となり、気液分離器頂部から液が流出するために、気液分離器内の液はほとんど満液となる。
However, the conventional refrigeration and air-conditioning apparatus has the following problems.
First, as in the conventional example described in Patent Document 1, when performing injection with a gas-liquid separator, the amount of liquid in the gas-liquid separator varies depending on the amount of injection, and accordingly, the amount of liquid refrigerant in the refrigeration cycle is distributed. Fluctuated and the operation became unstable.
When the injected gas refrigerant flow rate and the gas refrigerant flow rate of the two-phase refrigerant flowing into the gas-liquid separator are balanced, only the liquid refrigerant flows out to the evaporator side, Although the amount of liquid refrigerant is stable, the flow rate of injected refrigerant decreases, and when the refrigerant flow rate becomes smaller than the gas refrigerant flow rate flowing into the gas-liquid separator, the gas refrigerant also flows out to the evaporator side. Since the gas flows out from the bottom of the vessel, the liquid in the gas-liquid separator is almost discharged.
On the contrary, when the flow rate of the injected refrigerant increases, the gas refrigerant is insufficient, so the liquid refrigerant is also injected into the gas refrigerant, and the liquid flows out from the top of the gas-liquid separator. The liquid inside is almost full.

インジェクション流量は冷凍サイクルの高低圧や気液分離器の圧力、および圧縮機の運転容量などによって変動しやすいため、インジェクション流量が気液分離器に流入するガス冷媒流量と釣り合うことはほとんどなく、実際は気液分離器内の液冷媒量はほとんど0か満液の状態となり、運転状況に応じて、気液分離器内の冷媒量変動が生じやすい。その結果、冷凍サイクル内の冷媒量分布が変動し、運転の不安定が生じやすくなる。
このような気液分離器内の冷媒量変動に伴う運転不安定は、特許文献2記載の従来例のように、高圧液冷媒の一部をバイパスしてインジェクションする形式をとると、液貯留部が存在しないために解決される。しかし、この形式をとっても以下のような問題が残る。
The injection flow rate is likely to fluctuate depending on the high and low pressures of the refrigeration cycle, the pressure of the gas-liquid separator, the operating capacity of the compressor, etc., so the injection flow rate rarely matches the gas refrigerant flow rate flowing into the gas-liquid separator. The amount of liquid refrigerant in the gas-liquid separator is almost zero or full, and the amount of refrigerant in the gas-liquid separator is likely to vary depending on the operating conditions. As a result, the refrigerant amount distribution in the refrigeration cycle fluctuates and operation instability is likely to occur.
Such operation instability due to fluctuations in the amount of refrigerant in the gas-liquid separator takes the form of bypassing a part of the high-pressure liquid refrigerant and injecting it as in the conventional example described in Patent Document 2. Is solved because there is no. However, the following problems remain even if this format is adopted.

一般にガスインジェクションを行う冷凍サイクルでは、インジェクション流量を増加させ、圧縮機から吐出され室内熱交換器に流入する冷媒流量が増加するほど暖房能力を増加させることができる。
しかし、インジェクション流量を増加させると、ガス冷媒に混じって液冷媒もインジェクションされるようになり、圧縮機吐出温度が低下し、室内熱交換器入口の冷媒温度も低下することにより室内熱交換器の熱交換能力が低下する。従って、冷媒流量と熱交換能力との釣り合いで暖房能力最大となるインジェクション流量が存在する。
通常の空気熱源式ヒートポンプ冷凍空調装置では、外気が−10℃以下となるような寒冷地では暖房能力が低下し、十分な暖房運転が行えない状況にあり、より多くの暖房能力を発揮できる装置が求められているが、前述したようなガスインジェクションサイクルでは、暖房能力の限界があり、十分な暖房運転が行えないという問題があった。
In general, in a refrigeration cycle in which gas injection is performed, the heating capacity can be increased as the injection flow rate is increased and the refrigerant flow rate discharged from the compressor and flowing into the indoor heat exchanger is increased.
However, when the injection flow rate is increased, the liquid refrigerant is also injected into the gas refrigerant, the compressor discharge temperature is lowered, and the refrigerant temperature at the inlet of the indoor heat exchanger is also lowered. Heat exchange capacity is reduced. Therefore, there exists an injection flow rate that maximizes the heating capacity in balance between the refrigerant flow rate and the heat exchange capacity.
In a normal air heat source type heat pump refrigeration air conditioner, the heating capacity is lowered in a cold district where the outside air is -10 ° C. or less, and sufficient heating operation cannot be performed. However, in the gas injection cycle as described above, there is a problem that the heating capacity is limited and sufficient heating operation cannot be performed.

また、特許文献3記載の従来例においても、その回路構成には暖房能力を増加させる作用は無く、同様に寒冷地での暖房能力が低下し十分な暖房運転が行えないという問題があった。
この発明は以上の課題に鑑み、冷凍空調装置内の暖房能力を従来のガスインジェクションサイクルよりも向上させ、外気が−10℃以下となるような寒冷地においても十分な暖房能力を発揮できる冷凍空調装置を得ることを目的とする。
Further, even in the conventional example described in Patent Document 3, there is a problem that the circuit configuration does not have an effect of increasing the heating capacity, and similarly, the heating capacity in a cold region is lowered and sufficient heating operation cannot be performed.
In view of the above problems, the present invention improves the heating capacity in a refrigeration air conditioner over the conventional gas injection cycle, and can exhibit sufficient heating capacity even in a cold district where the outside air is -10 ° C or lower. The object is to obtain a device.

本発明に係る冷凍空調装置は、圧縮機、室内熱交換器、第1の減圧装置、室外熱交換器を環状に接続し、前記室内熱交換器から温熱を供給する冷凍空調装置において、前記室内熱交換器と前記第1の減圧装置との間の冷媒と、前記室外熱交換器と前記圧縮機との間の冷媒とを熱交換する第1の内部熱交換器と、前記室内熱交換器と前記第1の減圧装置との間の冷媒を、一部バイパスして前記圧縮機内の圧縮室にインジェクションするインジェクション回路と、該インジェクション回路に設けられたインジェクション用減圧装置と、該インジェクション用減圧装置で減圧された冷媒と前記室内熱交換器と前記第1の減圧装置との間の冷媒とを熱交換する第2の内部熱交換器とを備えてなるものである。   The refrigerating and air-conditioning apparatus according to the present invention includes a compressor, an indoor heat exchanger, a first pressure reducing device, and an outdoor heat exchanger connected in a ring shape, and supplying hot heat from the indoor heat exchanger. A first internal heat exchanger that exchanges heat between the refrigerant between the heat exchanger and the first pressure reducing device, and the refrigerant between the outdoor heat exchanger and the compressor; and the indoor heat exchanger. Injection circuit for partially bypassing the refrigerant between the first decompression device and the compression chamber in the compressor, the decompression device for injection provided in the injection circuit, and the decompression device for injection And a second internal heat exchanger for exchanging heat between the refrigerant depressurized in step 1 and the refrigerant between the indoor heat exchanger and the first decompression device.

以上説明したように本発明によれば、圧縮機、室内熱交換器、第1の減圧装置、室外熱交換器を環状に接続し、前記室内熱交換器から温熱を供給する暖房運転を行う場合に、室内熱交換器と第1の減圧装置との間の冷媒と、室外熱交換器と圧縮機との間の冷媒とを熱交換する第1の内部熱交換器により、圧縮機吸入の冷媒を加熱することで、室内熱交換器と第1の減圧装置との間の冷媒を一部バイパスして圧縮機内の圧縮室にインジェクションされる冷媒流量を多量としても、圧縮機の吐出温度の低下を抑制し、室内熱交換器で十分な熱交換性能を発揮させることにより、低外気条件などで暖房能力が低下しやすい条件でも十分な暖房能力を確保することができると共に、インジェクション用減圧装置で減圧された冷媒と室内熱交換器と第1の減圧装置との間の冷媒とを熱交換する第2の内部熱交換器により、ガスインジェクションを行う冷媒を供給するときに、気液分離器によらず、バイパスされた冷媒をガス化し供給することで、気液分離器を用いることによる液量変動を回避し、より安定した装置の運転を実現することができるという効果がある。   As described above, according to the present invention, when the compressor, the indoor heat exchanger, the first pressure reducing device, and the outdoor heat exchanger are connected in a ring shape, and heating operation is performed to supply warm heat from the indoor heat exchanger. In addition, the first internal heat exchanger that exchanges heat between the refrigerant between the indoor heat exchanger and the first pressure reducing device and the refrigerant between the outdoor heat exchanger and the compressor, Even if the refrigerant flow between the indoor heat exchanger and the first pressure reducing device is partially bypassed and the refrigerant flow rate injected into the compression chamber in the compressor is increased, the discharge temperature of the compressor is reduced. In addition, it is possible to ensure sufficient heating capacity even under conditions where the heating capacity is likely to be reduced due to low outside air conditions, etc. by exhibiting sufficient heat exchange performance with the indoor heat exchanger, and with a decompression device for injection Reduced refrigerant, indoor heat exchanger and first When supplying the refrigerant for performing gas injection by the second internal heat exchanger that exchanges heat with the refrigerant between the decompression device, the bypassed refrigerant is gasified and supplied without using the gas-liquid separator. Thus, there is an effect that it is possible to avoid the fluctuation of the liquid amount due to the use of the gas-liquid separator and to realize more stable operation of the apparatus.

実施の形態1.
図1は本発明に係る実施の形態1の冷凍空調装置の冷媒回路図である。
図1において、室外機1内には圧縮機3、暖房と冷房の運転切換を行う四方弁4、室外熱交換器12、減圧装置である第1膨張弁11、第2内部熱交換器10、第1内部熱交換器9、減圧装置である第2膨張弁8、インジェクション回路13、インジェクション用減圧装置である第3膨張弁14が搭載されている。
圧縮機3はインバータにより回転数が制御され容量制御されるタイプであり、圧縮機3内の圧縮室内にインジェクション回路13から供給される冷媒をインジェクションすることが可能な構造となっている。
Embodiment 1 FIG.
1 is a refrigerant circuit diagram of a refrigerating and air-conditioning apparatus according to Embodiment 1 of the present invention.
In FIG. 1, an outdoor unit 1 includes a compressor 3, a four-way valve 4 for switching between heating and cooling, an outdoor heat exchanger 12, a first expansion valve 11 that is a decompression device, a second internal heat exchanger 10, A first internal heat exchanger 9, a second expansion valve 8, which is a pressure reducing device, an injection circuit 13, and a third expansion valve 14, which is a pressure reducing device for injection, are mounted.
The compressor 3 is of a type in which the rotation speed is controlled by an inverter and the capacity is controlled, and has a structure capable of injecting the refrigerant supplied from the injection circuit 13 into the compression chamber in the compressor 3.

また第1膨張弁11、第2膨張弁8、第3膨張弁14は開度が可変に制御される電子膨張弁である。また室外熱交換器12はファンなどで送風される外気と熱交換する。
室内機2内には室内熱交換器6が搭載されている。ガス管5、液管7は室外機1と室内機2を接続する接続配管である。この冷凍空調装置の冷媒としてはHFC系の混合冷媒であるR410Aが用いられる。
The first expansion valve 11, the second expansion valve 8, and the third expansion valve 14 are electronic expansion valves whose opening degree is variably controlled. The outdoor heat exchanger 12 exchanges heat with the outside air blown by a fan or the like.
An indoor heat exchanger 6 is mounted in the indoor unit 2. The gas pipe 5 and the liquid pipe 7 are connecting pipes that connect the outdoor unit 1 and the indoor unit 2. R410A, which is an HFC mixed refrigerant, is used as the refrigerant of this refrigeration air conditioner.

室外機1内には計測制御装置15及び各温度センサ16が設置されている。温度センサ16aが圧縮機3の吐出側、温度センサ16bが室外熱交換器12と四方弁4の間、温度センサ16cが室外熱交換器12の中間部の冷媒流路上、温度センサ16dが室外熱交換器12と第1膨張弁11の間、温度センサ16eが第1内部熱交換器9と第2膨張弁8との間、温度センサ16fが圧縮機3の吸入側に設けられ、それぞれ設置場所の冷媒温度を計測する。また温度センサ16gは室外機1の周囲の外気温度を計測する。   A measurement control device 15 and temperature sensors 16 are installed in the outdoor unit 1. The temperature sensor 16 a is on the discharge side of the compressor 3, the temperature sensor 16 b is between the outdoor heat exchanger 12 and the four-way valve 4, the temperature sensor 16 c is on the refrigerant flow path in the middle of the outdoor heat exchanger 12, and the temperature sensor 16 d is outdoor heat. Between the exchanger 12 and the first expansion valve 11, a temperature sensor 16 e is provided between the first internal heat exchanger 9 and the second expansion valve 8, and a temperature sensor 16 f is provided on the suction side of the compressor 3. Measure the refrigerant temperature. The temperature sensor 16g measures the outside air temperature around the outdoor unit 1.

室内機2内には温度センサ16h、16i、16jが設置されており、温度センサ16hは室内熱交換器6の中間部の冷媒流路上、温度センサ16iは室内熱交換器6と液管7の間に設けられており、それぞれ設置場所での冷媒温度を計測する。温度センサ16jは室内熱交換器6に吸気される空気温度を計測する。なお、負荷となる熱媒体が水など他の媒体である場合には温度センサ16jはその媒体の流入温度を計測する。   Temperature sensors 16 h, 16 i, 16 j are installed in the indoor unit 2, the temperature sensor 16 h is on the refrigerant flow path in the middle part of the indoor heat exchanger 6, and the temperature sensor 16 i is connected to the indoor heat exchanger 6 and the liquid pipe 7. The temperature of the refrigerant at each installation location is measured. The temperature sensor 16j measures the temperature of air taken into the indoor heat exchanger 6. When the heat medium serving as a load is another medium such as water, the temperature sensor 16j measures the inflow temperature of the medium.

温度センサ16c、16hはそれぞれ熱交換器中間で気液二相状態となっている冷媒温度を検知することにより、高低圧の冷媒飽和温度を検知することができる。
また室外機1内の計測制御装置15は温度センサ16の計測情報や、冷凍空調装置使用者から指示される運転内容に基づいて、圧縮機3の運転方法、四方弁4の流路切換、室外熱交換器12のファン送風量、各膨張弁の開度などを制御する。
The temperature sensors 16c and 16h can detect the refrigerant saturation temperature at high and low pressure by detecting the refrigerant temperature in the gas-liquid two-phase state in the middle of the heat exchanger.
In addition, the measurement control device 15 in the outdoor unit 1 is based on the measurement information of the temperature sensor 16 and the operation content instructed by the user of the refrigeration air conditioner, the operation method of the compressor 3, the flow path switching of the four-way valve 4, the outdoor It controls the fan air flow rate of the heat exchanger 12, the opening degree of each expansion valve, and the like.

次に、この冷凍空調装置での運転動作について説明する。
まず暖房運転時の動作について図1および図2に示す暖房運転時のPH線図をもとに説明する。
暖房運転時には、四方弁4の流路は図1の実線方向に設定される。そして圧縮機3から吐出された高温高圧のガス冷媒(図2点1)は四方弁4を経て室外機1を流出しガス管5を経て室内機2に流入する。そして、室内熱交換器6に流入し、凝縮器となる室内熱交換器6で放熱しながら凝縮液化し高圧低温の液冷媒となる(図2点2)。冷媒から放熱された熱を負荷側の空気や水などの負荷側媒体に与えることで暖房を行う。
Next, the operation of this refrigeration air conditioner will be described.
First, the operation during the heating operation will be described with reference to the PH diagrams during the heating operation shown in FIGS.
During the heating operation, the flow path of the four-way valve 4 is set in the direction of the solid line in FIG. The high-temperature and high-pressure gas refrigerant (point 1 in FIG. 2) discharged from the compressor 3 flows out of the outdoor unit 1 through the four-way valve 4 and flows into the indoor unit 2 through the gas pipe 5. Then, it flows into the indoor heat exchanger 6 and condenses and liquefies while dissipating heat in the indoor heat exchanger 6 serving as a condenser to become a high-pressure and low-temperature liquid refrigerant (point 2 in FIG. 2). Heating is performed by applying heat radiated from the refrigerant to a load-side medium such as air or water on the load side.

室内熱交換器6を出た高圧低温の冷媒は液管7を経由して、室外機1に流入した後で、第2膨張弁8で若干減圧された後(図2点3)で、第1内部熱交換器9で圧縮機3に吸入される低温の冷媒に熱を与え冷却される(図2点4)。
そして、インジェクション回路13に一部冷媒をバイパスした後で、第2内部熱交換器10で、インジェクション回路13にバイパスされ第3膨張弁14で減圧され低温となった冷媒と熱交換し、さらに冷却される(図2点5)。その後、冷媒は第1膨張弁11で低圧まで減圧され二相冷媒となり(図2点6)、その後蒸発器となる室外熱交換器12に流入し、そこで吸熱し、蒸発ガス化される(図2点7)。その後、四方弁4を経て第1内部熱交換器9で高圧の冷媒と熱交換し、さらに加熱され(図2点8)、圧縮機3に吸入される。
The high-pressure and low-temperature refrigerant that has exited the indoor heat exchanger 6 flows into the outdoor unit 1 via the liquid pipe 7, and after being slightly decompressed by the second expansion valve 8 (point 3 in FIG. 2), 1 Heat is applied to the low-temperature refrigerant sucked into the compressor 3 by the internal heat exchanger 9 to cool it (point 4 in FIG. 2).
Then, after partially bypassing the refrigerant to the injection circuit 13, the second internal heat exchanger 10 exchanges heat with the refrigerant that has been bypassed by the injection circuit 13 and depressurized by the third expansion valve 14 to a low temperature, and further cooled. (5 in FIG. 2). Thereafter, the refrigerant is depressurized to a low pressure by the first expansion valve 11 to become a two-phase refrigerant (point 6 in FIG. 2), and then flows into the outdoor heat exchanger 12 serving as an evaporator, where it absorbs heat and is evaporated and gasified (see FIG. 2 points 7). Thereafter, the heat is exchanged with the high-pressure refrigerant in the first internal heat exchanger 9 through the four-way valve 4, further heated (point 8 in FIG. 2), and sucked into the compressor 3.

一方、インジェクション回路13にバイパスされた冷媒は、第3膨張弁14で、中間圧まで減圧され、低温の二相冷媒となり(図2点9)、その後は第2内部熱交換器10で高圧冷媒と熱交換し加熱され(図2点10)、圧縮機3にインジェクションされる。
圧縮機3内部では、吸入された冷媒(図2点8)が中間圧まで圧縮、加熱された(図2点11)後で、インジェクションされる冷媒と合流し、温度低下した後で(図2点12)、高圧まで圧縮され吐出される(図2点1)。
On the other hand, the refrigerant bypassed to the injection circuit 13 is depressurized to the intermediate pressure by the third expansion valve 14 to become a low-temperature two-phase refrigerant (point 9 in FIG. 2), and then the high-pressure refrigerant in the second internal heat exchanger 10. The heat is exchanged and heated (point 10 in FIG. 2) and injected into the compressor 3.
Inside the compressor 3, the sucked refrigerant (point 8 in FIG. 2) is compressed and heated to an intermediate pressure (point 11 in FIG. 2), and then merged with the refrigerant to be injected and the temperature is lowered (FIG. 2). Point 12), compressed to high pressure and discharged (point 1 in FIG. 2).

次に冷房運転時の動作について図1および図3に示す冷房運転時のPH線図をもとに説明する。
冷房運転時には、四方弁4の流路は図1の点線方向に設定される。そして、圧縮機3から吐出された高温高圧のガス冷媒(図3点1)は四方弁4を経て凝縮器となる室外熱交換器12に流入し、ここで放熱しながら凝縮液化し、高圧低温の冷媒となる(図3点2)。 室外熱交換器12を出た冷媒は第1膨張弁11で若干減圧された後で(図3点3)、第2内部熱交換器10で、インジェクション回路13を流れる低温の冷媒と熱交換し冷却され(図3点4)、ここで一部冷媒をインジェクション回路13にバイパスした後、引き続き第1内部熱交換器9で、圧縮機3に吸入される冷媒と熱交換し冷却される(図3点5)。
Next, the operation during the cooling operation will be described based on the PH diagrams during the cooling operation shown in FIGS. 1 and 3.
During the cooling operation, the flow path of the four-way valve 4 is set in the direction of the dotted line in FIG. Then, the high-temperature and high-pressure gas refrigerant (point 1 in FIG. 3) discharged from the compressor 3 flows into the outdoor heat exchanger 12 serving as a condenser through the four-way valve 4, where it condenses and liquefies while radiating heat. (Refer to point 2 in FIG. 3). The refrigerant leaving the outdoor heat exchanger 12 is slightly decompressed by the first expansion valve 11 (point 3 in FIG. 3), and then exchanges heat with the low-temperature refrigerant flowing through the injection circuit 13 by the second internal heat exchanger 10. The refrigerant is cooled (point 4 in FIG. 3), and after a part of the refrigerant is bypassed to the injection circuit 13, the first internal heat exchanger 9 continues to exchange heat with the refrigerant sucked into the compressor 3 and is cooled (FIG. 3). 3 points 5).

その後、第2膨張弁8で低圧まで減圧され二相冷媒となった後で(図3点6)、室外機1を流出し、液管7を経て室内機2に流入する。そして、蒸発器となる室内熱交換器6に流入し、そこで吸熱し、蒸発ガス化(図3点7)しながら室内機2側の空気や水などの負荷側媒体に冷熱を供給する。
室内熱交換器6を出た低圧ガス冷媒は室内機2を出て、ガス管5を経て室外機1に流入し、四方弁4を経た後で、第1内部熱交換器9で高圧冷媒と熱交換し加熱された後で(図3点8)、圧縮機3に吸入される。
Thereafter, the pressure is reduced to a low pressure by the second expansion valve 8 to become a two-phase refrigerant (point 6 in FIG. 3), and then flows out of the outdoor unit 1 and flows into the indoor unit 2 through the liquid pipe 7. And it flows in the indoor heat exchanger 6 used as an evaporator, absorbs heat there, and supplies cold heat to a load side medium such as air or water on the indoor unit 2 side while evaporating gas (7 in FIG. 3).
The low-pressure gas refrigerant that has exited the indoor heat exchanger 6 exits the indoor unit 2, flows into the outdoor unit 1 through the gas pipe 5, passes through the four-way valve 4, and then enters the high-pressure refrigerant in the first internal heat exchanger 9. After heat exchange and heating (point 8 in FIG. 3), the air is sucked into the compressor 3.

一方、インジェクション回路13にバイパスされた冷媒は、第3膨張弁14で、中間圧まで減圧され、低温の二相冷媒となり(図3点9)、その後に第2内部熱交換器10で高圧冷媒と熱交換し加熱され(図3点10)、圧縮機3にインジェクションされる。圧縮機3内部では、吸入された冷媒(図3点8)が中間圧まで圧縮、加熱された(図3点11)後で、インジェクションされる冷媒と合流し、温度低下した後で(図3点12)、再度高圧まで圧縮され吐出される(図3点1)。
冷房運転時のPH線図は暖房運転時とほぼ同一になり、どちらの運転モードでも同様の運転を実現できる。
On the other hand, the refrigerant bypassed to the injection circuit 13 is decompressed to the intermediate pressure by the third expansion valve 14 to become a low-temperature two-phase refrigerant (point 9 in FIG. 3), and then the high-pressure refrigerant in the second internal heat exchanger 10. The heat is exchanged and heated (point 10 in FIG. 3) and injected into the compressor 3. Inside the compressor 3, the sucked refrigerant (point 8 in FIG. 3) is compressed and heated to an intermediate pressure (point 11 in FIG. 3), and then merged with the refrigerant to be injected and after the temperature drops (FIG. 3). Point 12), compressed again to high pressure and discharged (point 1 in FIG. 3).
The PH diagram during the cooling operation is almost the same as that during the heating operation, and the same operation can be realized in either operation mode.

次に、この冷凍空調装置での運転制御動作について説明する。
まず、暖房運転時の制御動作について図4のフローチャートに基づいて説明する。
暖房運転時には、まず圧縮機3の容量、第1膨張弁11の開度、第2膨張弁8の開度、第3膨張弁14の開度が初期値に設定される(ステップS1)。
そして、それから所定時間経過すると(ステップS2)、それ以降運転状態に応じた各アクチュエータは以下のように制御される。
また、圧縮機3の容量は、基本的に室内機2の温度センサ16jで計測される空気温度が、冷凍空調装置使用者が設定する温度になるように制御される。
Next, the operation control operation in this refrigeration air conditioner will be described.
First, the control operation during the heating operation will be described based on the flowchart of FIG.
During the heating operation, first, the capacity of the compressor 3, the opening of the first expansion valve 11, the opening of the second expansion valve 8, and the opening of the third expansion valve 14 are set to initial values (step S1).
Then, when a predetermined time has elapsed (step S2), the actuators corresponding to the operating state are controlled as follows.
The capacity of the compressor 3 is basically controlled such that the air temperature measured by the temperature sensor 16j of the indoor unit 2 becomes a temperature set by the user of the refrigeration air conditioner.

即ち、室内機2の空気温度と設定値とを比較する(ステップS3)。そして、空気温度が設定温度と等しいか或いは近接している場合には、圧縮機3の容量はそのまま維持されて次のステップに進む。
また、空気温度が設定温度より大きく低下している場合は、圧縮機3の容量は増加され、空気温度が設定温度に近接している場合には、圧縮機3の容量はそのまま維持され、空気温度が設定温度より高くなる場合には圧縮機3の容量は低下されるというように圧縮機3の容量を変更する(ステップS4)。
That is, the air temperature of the indoor unit 2 is compared with the set value (step S3). When the air temperature is equal to or close to the set temperature, the capacity of the compressor 3 is maintained as it is, and the process proceeds to the next step.
When the air temperature is significantly lower than the set temperature, the capacity of the compressor 3 is increased. When the air temperature is close to the set temperature, the capacity of the compressor 3 is maintained as it is, and the air When the temperature becomes higher than the set temperature, the capacity of the compressor 3 is changed so that the capacity of the compressor 3 is reduced (step S4).

各膨張弁の制御は以下のように行われる。
まず、第2膨張弁8は、温度センサ16hで検知される高圧冷媒の飽和温度と温度センサ16iで検知される室内熱交換器6の出口温度との差温で得られる室内熱交換器6出口の冷媒過冷却度SCが予め設定された目標値、例えば10℃になるように制御される。
即ち、室内熱交換器6出口の冷媒過冷却度SCと目標値とを比較する(ステップS5)。そして、室内熱交換器6出口の冷媒過冷却度SCが目標値と等しいか或いは近接している場合には、第2膨張弁8の開度はそのまま維持されて次のステップに進む。
また、室内熱交換器6出口の冷媒過冷却度SCが目標値より大きい場合には、第2膨張弁8の開度は大きく、冷媒過冷却度SCが目標値より小さい場合には、第2膨張弁8の開度は小さく制御されるというように第2膨張弁8の開度を変更する(ステップS6)。
Each expansion valve is controlled as follows.
First, the second expansion valve 8 has an outlet of the indoor heat exchanger 6 that is obtained by a differential temperature between the saturation temperature of the high-pressure refrigerant detected by the temperature sensor 16h and the outlet temperature of the indoor heat exchanger 6 detected by the temperature sensor 16i. The refrigerant supercooling degree SC is controlled to be a preset target value, for example, 10 ° C.
That is, the refrigerant supercooling degree SC at the outlet of the indoor heat exchanger 6 is compared with the target value (step S5). When the refrigerant supercooling degree SC at the outlet of the indoor heat exchanger 6 is equal to or close to the target value, the opening degree of the second expansion valve 8 is maintained as it is, and the process proceeds to the next step.
When the refrigerant supercooling degree SC at the outlet of the indoor heat exchanger 6 is larger than the target value, the opening degree of the second expansion valve 8 is large, and when the refrigerant subcooling degree SC is smaller than the target value, the second degree. The opening degree of the second expansion valve 8 is changed so that the opening degree of the expansion valve 8 is controlled to be small (step S6).

次に、第1膨張弁11は、温度センサ16fで検知される圧縮機3吸入温度と温度センサ16cで検知される低圧冷媒の飽和温度との差温で検知される圧縮機3吸入の冷媒過熱度SHが予め設定された目標値、例えば10℃になるように制御される。
即ち、圧縮機3吸入の冷媒過熱度SHと目標値とを比較する(ステップS7)。そして、圧縮機3吸入の冷媒過熱度SHが目標値と等しいか或いは近接している場合には、第1膨張弁11の開度はそのまま維持されて次のステップに進む。
また、圧縮機3吸入の冷媒過熱度SHが目標値より大きい場合には、第1膨張弁11の開度は大きく、冷媒過熱度SHが目標値より小さい場合には、第1膨張弁11の開度は小さくされるというように第1膨張弁11の開度を変更する(ステップS8)。
Next, the first expansion valve 11 has the refrigerant 3 superheated by the compressor 3 detected by the temperature difference between the compressor 3 intake temperature detected by the temperature sensor 16f and the saturation temperature of the low-pressure refrigerant detected by the temperature sensor 16c. The degree SH is controlled to be a preset target value, for example, 10 ° C.
That is, the refrigerant superheating degree SH sucked in the compressor 3 is compared with the target value (step S7). When the refrigerant superheat degree SH sucked into the compressor 3 is equal to or close to the target value, the opening degree of the first expansion valve 11 is maintained as it is, and the process proceeds to the next step.
Further, when the refrigerant superheat degree SH sucked by the compressor 3 is larger than the target value, the opening degree of the first expansion valve 11 is large, and when the refrigerant superheat degree SH is smaller than the target value, the first expansion valve 11 The opening degree of the first expansion valve 11 is changed so that the opening degree is reduced (step S8).

更に、第3膨張弁14は、温度センサ16aで検知される圧縮機3の吐出温度が予め設定された目標値、例えば90℃になるように制御される。
即ち、圧縮機3の吐出温度と目標値とを比較する(ステップS9)。そして、圧縮機3の吐出温度が目標値と等しいか或いは近接している場合には、第3膨張弁14の開度はそのまま維持されてステップS2に戻る。
第3膨張弁14の開度を変化させた時の冷媒状態変化は以下のようになる。
第3膨張弁14の開度が大きくなると、インジェクション回路13に流れる冷媒流量が増加する。第2内部熱交換器10での熱交換量はインジェクション回路13の流量によって、大きく変化しないので、インジェクション回路13に流れる冷媒流量が増加すると、第2内部熱交換器10でのインジェクション回路13側の冷媒エンタルピ差(図2の点9→10の差)は小さくなり、インジェクションされる冷媒エンタルピ(図2点10)は低下する。
Further, the third expansion valve 14 is controlled so that the discharge temperature of the compressor 3 detected by the temperature sensor 16a becomes a preset target value, for example, 90 ° C.
That is, the discharge temperature of the compressor 3 is compared with the target value (step S9). When the discharge temperature of the compressor 3 is equal to or close to the target value, the opening degree of the third expansion valve 14 is maintained as it is, and the process returns to step S2.
The refrigerant state change when the opening degree of the third expansion valve 14 is changed is as follows.
When the opening degree of the third expansion valve 14 increases, the flow rate of the refrigerant flowing through the injection circuit 13 increases. Since the amount of heat exchange in the second internal heat exchanger 10 does not change greatly depending on the flow rate of the injection circuit 13, if the flow rate of the refrigerant flowing through the injection circuit 13 increases, the heat exchange amount on the injection circuit 13 side of the second internal heat exchanger 10 is increased. The refrigerant enthalpy difference (difference between points 9 and 10 in FIG. 2) decreases, and the injected refrigerant enthalpy (point 10 in FIG. 2) decreases.

従って、インジェクションされた冷媒が合流後の冷媒エンタルピ(図2点12)のエンタルピも低下し、その結果、圧縮機3の吐出エンタルピ(図2点1)も低下し、圧縮機3の吐出温度は低下する。
逆に、第3膨張弁14の開度が小さくなると、圧縮機3の吐出エンタルピは上昇し、圧縮機3の吐出温度は上昇する。従って、第3膨張弁14の開度制御は、圧縮機3の吐出温度が目標値より高い場合には、第3膨張弁14の開度を大きく制御し、逆に吐出温度が目標値より低い場合には第3膨張弁14の開度を小さく制御するというように第3膨張弁14の開度を変更し(ステップS10)、その後はステップS2に戻る。
Therefore, the enthalpy of the refrigerant enthalpy (point 12 in FIG. 2) after the injected refrigerant merges also decreases. As a result, the discharge enthalpy (point 1 in FIG. 2) of the compressor 3 also decreases, and the discharge temperature of the compressor 3 becomes descend.
Conversely, when the opening of the third expansion valve 14 decreases, the discharge enthalpy of the compressor 3 rises and the discharge temperature of the compressor 3 rises. Therefore, the opening degree control of the third expansion valve 14 controls the opening degree of the third expansion valve 14 to be large when the discharge temperature of the compressor 3 is higher than the target value, and conversely the discharge temperature is lower than the target value. In this case, the opening degree of the third expansion valve 14 is changed such that the opening degree of the third expansion valve 14 is controlled to be small (step S10), and thereafter, the process returns to step S2.

次に冷房運転時の制御動作について図5のフローチャートに基づいて説明する。
冷房運転時には、まず圧縮機3の容量、第1膨張弁11の開度、第2膨張弁8の開度、第3膨張弁14の開度が初期値に設定される(ステップS11)。
それから所定時間経過すると(ステップS12)、それ以降運転状態に応じた各アクチュエータは以下のように制御される。
Next, the control operation during the cooling operation will be described based on the flowchart of FIG.
During the cooling operation, first, the capacity of the compressor 3, the opening of the first expansion valve 11, the opening of the second expansion valve 8, and the opening of the third expansion valve 14 are set to initial values (step S11).
Thereafter, when a predetermined time elapses (step S12), each actuator corresponding to the operating state is controlled as follows.

まず、圧縮機3の容量は、基本的に室内機2の温度センサ16jで計測される空気温度が、冷凍空調装置使用者が設定する温度になるように制御される。
即ち、室内機2の空気温度と設定温度とを比較する(ステップS13)。そして、空気温度が設定温度と等しいか或いは近接している場合には、圧縮機3の容量はそのまま維持されて次のステップに進む。
また、空気温度が設定温度より大きく上昇している場合は、圧縮機3の容量は増加され、空気温度が設定温度より低くなる場合には圧縮機3の容量は低下されるというように圧縮機3の容量を変更する(ステップS14)。
First, the capacity of the compressor 3 is basically controlled such that the air temperature measured by the temperature sensor 16j of the indoor unit 2 becomes a temperature set by the user of the refrigeration air conditioner.
That is, the air temperature of the indoor unit 2 is compared with the set temperature (step S13). When the air temperature is equal to or close to the set temperature, the capacity of the compressor 3 is maintained as it is, and the process proceeds to the next step.
When the air temperature is higher than the set temperature, the capacity of the compressor 3 is increased. When the air temperature is lower than the set temperature, the capacity of the compressor 3 is decreased. 3 is changed (step S14).

各膨張弁の制御は以下のように行われる。
まず、第1膨張弁11は、温度センサ16cで検知される高圧冷媒の飽和温度と温度センサ16dで検知される室外熱交換器12の出口温度との差温で得られる室外熱交換器12出口の冷媒過冷却度SCが予め設定された目標値、例えば10℃になるように制御される。
即ち、室外熱交換器12出口の冷媒過冷却度SCと目標値とを比較する(ステップS15)。そして、室外熱交換器12出口の冷媒過冷却度SCが目標値と等しいか或いは近接している場合には、第1膨張弁11の開度はそのまま維持されて次のステップに進む。
また、室外熱交換器12出口の冷媒過冷却度SCが目標値より大きい場合には、第1膨張弁11の開度は大きく、冷媒過冷却度SCが目標値より小さい場合には、第1膨張弁11の開度は小さく制御されるというように第1膨張弁11の開度を変更する(ステップS16)。
Each expansion valve is controlled as follows.
First, the first expansion valve 11 has an outdoor heat exchanger 12 outlet that is obtained by the difference between the saturation temperature of the high-pressure refrigerant detected by the temperature sensor 16c and the outlet temperature of the outdoor heat exchanger 12 detected by the temperature sensor 16d. The refrigerant supercooling degree SC is controlled to be a preset target value, for example, 10 ° C.
That is, the refrigerant supercooling degree SC at the outlet of the outdoor heat exchanger 12 is compared with the target value (step S15). When the refrigerant supercooling degree SC at the outlet of the outdoor heat exchanger 12 is equal to or close to the target value, the opening degree of the first expansion valve 11 is maintained as it is, and the process proceeds to the next step.
When the refrigerant supercooling degree SC at the outlet of the outdoor heat exchanger 12 is larger than the target value, the opening degree of the first expansion valve 11 is large, and when the refrigerant supercooling degree SC is smaller than the target value, the first The opening degree of the first expansion valve 11 is changed so that the opening degree of the expansion valve 11 is controlled to be small (step S16).

次に、第2膨張弁8は、温度センサ16fで検知される圧縮機3吸入温度と温度センサ16hで検知される低圧冷媒の飽和温度との差温で検知される圧縮機3吸入の冷媒過熱度SHが予め設定された目標値、例えば10℃になるように制御される。
即ち、圧縮機3吸入の冷媒過熱度SHと目標値とを比較する(ステップS17)。そして、圧縮機3吸入の冷媒過熱度SHと目標値と等しいか或いは近接している場合には、第2膨張弁8の開度はそのまま維持されて次のステップに進む。
また、圧縮機3吸入の冷媒過熱度SHが目標値より大きい場合には、第2膨張弁8の開度は大きく、冷媒過熱度SHが目標値より小さい場合には、第3膨張弁8の開度は小さく制御されるというように第2膨張弁8の開度を変更する(ステップS18)。
Next, the second expansion valve 8 is connected to the compressor 3 suction refrigerant detected by the temperature difference between the compressor 3 suction temperature detected by the temperature sensor 16f and the saturation temperature of the low-pressure refrigerant detected by the temperature sensor 16h. The degree SH is controlled to be a preset target value, for example, 10 ° C.
That is, the refrigerant superheating degree SH sucked into the compressor 3 is compared with the target value (step S17). If the refrigerant superheating degree SH sucked into the compressor 3 is equal to or close to the target value, the opening degree of the second expansion valve 8 is maintained as it is, and the process proceeds to the next step.
Further, when the refrigerant superheat degree SH sucked by the compressor 3 is larger than the target value, the opening degree of the second expansion valve 8 is large, and when the refrigerant superheat degree SH is smaller than the target value, the third expansion valve 8 The opening degree of the second expansion valve 8 is changed so that the opening degree is controlled to be small (step S18).

次に、第3膨張弁14は、温度センサ16aで検知される圧縮機3の吐出温度が予め設定された目標値、例えば90℃になるように制御される。
即ち、圧縮機3の吐出温度と目標値とを比較する(ステップS19)。そして、圧縮機3の吐出温度が目標値と等しいか或いは近接している場合には、第3膨張弁8の開度はそのまま維持されてステップS12に戻る。
また、第3膨張弁14の開度を変化させた時の冷媒状態変化は暖房運転時と同様であるので、圧縮機3の吐出温度が目標値より高い場合には、第3膨張弁14の開度を大きく制御し、逆に吐出温度が目標値より低い場合には第3膨張弁14の開度を小さく制御するというように第3膨張弁14の開度を変更し(ステップS20)、ステップS12に戻る。
Next, the third expansion valve 14 is controlled so that the discharge temperature of the compressor 3 detected by the temperature sensor 16a becomes a preset target value, for example, 90 ° C.
That is, the discharge temperature of the compressor 3 is compared with the target value (step S19). When the discharge temperature of the compressor 3 is equal to or close to the target value, the opening degree of the third expansion valve 8 is maintained as it is and the process returns to step S12.
Moreover, since the refrigerant | coolant state change when changing the opening degree of the 3rd expansion valve 14 is the same as that at the time of heating operation, when the discharge temperature of the compressor 3 is higher than a target value, the 3rd expansion valve 14's The opening degree of the third expansion valve 14 is changed so that the opening degree is controlled to be large and, conversely, when the discharge temperature is lower than the target value, the opening degree of the third expansion valve 14 is controlled to be small (step S20). Return to step S12.

次に、本実施の形態の回路構成、および制御によって実現される作用効果について説明する。本装置の構成では、冷暖いずれの運転でも同様の運転を行えるので、以下特に暖房運転について説明する。
本装置の回路構成はいわゆるガスインジェクション回路となっている。即ち、凝縮器となる室内熱交換器6を出た後で中間圧まで減圧された冷媒のうちガス冷媒を圧縮機3にインジェクションする構成となっている。
Next, the circuit configuration of the present embodiment and the operational effects realized by the control will be described. In the configuration of the present apparatus, the same operation can be performed in both the cooling and heating operations, and therefore the heating operation will be particularly described below.
The circuit configuration of this apparatus is a so-called gas injection circuit. That is, the refrigerant is injected into the compressor 3 from among the refrigerant that has been discharged from the indoor heat exchanger 6 serving as a condenser and has been reduced to an intermediate pressure.

一般には、気液分離器で中間圧の冷媒を液・ガスに分離しインジェクションされる構成が多いが、本装置では、図6に示されるように、第2内部熱交換器10での熱交換により、熱的に液・ガスを分離し、インジェクションする構成としている。
ガスインジェクション回路とすることにより以下のような効果が得られる。
まず、ガスインジェクションを行うことにより、圧縮機3から吐出される冷媒流量が増加し、圧縮機3から吐出される冷媒流量Gdis=圧縮機3で吸入される冷媒流量Gsuc+インジェクションされる冷媒流量Ginjとなる。
従って、凝縮器となる熱交換器に流れる冷媒流量が増加するので、暖房運転の場合には、暖房能力が増加する。
In general, the gas-liquid separator often separates the intermediate pressure refrigerant into liquid / gas and is injected, but in this apparatus, as shown in FIG. 6, the heat exchange in the second internal heat exchanger 10 is performed. Thus, the liquid and gas are thermally separated and injected.
By using a gas injection circuit, the following effects can be obtained.
First, by performing gas injection, the refrigerant flow rate discharged from the compressor 3 increases, and the refrigerant flow rate Gdis discharged from the compressor 3 = the refrigerant flow rate Gsuc sucked by the compressor 3 + the injected refrigerant flow rate Ginj Become.
Therefore, since the flow rate of the refrigerant flowing through the heat exchanger serving as a condenser increases, the heating capacity increases in the heating operation.

一方、第2内部熱交換器10での熱交換により図6に示されるように、蒸発器となる熱交換器に流入する冷媒エンタルピが低下し、蒸発器での冷媒エンタルピ差が増大する。従って冷房運転時においても、冷房能力が増加する。
また、ガスインジェクションを行う場合は効率改善効果も得られる。
蒸発器に流入する冷媒は、一般に気液二相冷媒であるが、このうちガス冷媒は冷房能力に寄与しない。圧縮機3から見ると、この低圧のガス冷媒も、蒸発器で蒸発したガス冷媒と一緒に高圧に昇圧する仕事を行っている。
On the other hand, as shown in FIG. 6 due to heat exchange in the second internal heat exchanger 10, the refrigerant enthalpy flowing into the heat exchanger serving as an evaporator is lowered, and the refrigerant enthalpy difference in the evaporator is increased. Therefore, the cooling capacity increases even during the cooling operation.
In addition, when gas injection is performed, an efficiency improvement effect can be obtained.
The refrigerant flowing into the evaporator is generally a gas-liquid two-phase refrigerant, but the gas refrigerant does not contribute to the cooling capacity. When viewed from the compressor 3, this low-pressure gas refrigerant also works to increase the pressure together with the gas refrigerant evaporated in the evaporator.

ガスインジェクションを行うと、蒸発器に流入するガス冷媒のうちのいくらかを中間圧で抜き出して、インジェクションし、中間圧から高圧に昇圧し圧縮することになる。
従って、インジェクションされるガス冷媒の流量については、低圧から中間圧まで昇圧する圧縮仕事が不要になり、この分効率改善される。この効果は冷暖房のいずれの運転でも得られる。
When gas injection is performed, some of the gas refrigerant flowing into the evaporator is extracted at an intermediate pressure, injected, boosted from the intermediate pressure to a high pressure, and compressed.
Therefore, with respect to the flow rate of the injected gas refrigerant, compression work for increasing the pressure from a low pressure to an intermediate pressure becomes unnecessary, and the efficiency is improved accordingly. This effect can be obtained in any operation of air conditioning.

次に、ガスインジェクション流量と暖房能力の相関について説明する。
ガスインジェクション流量を増加すると、前述したように圧縮機3から吐出される冷媒流量は増加する一方で、圧縮機3の吐出温度は低下し凝縮器に流入する冷媒温度も低下する。
凝縮器の熱交換性能を見ると、一般に熱交換器内での温度分布が高い程熱交換量が増加する。同一凝縮温度で凝縮器入口の冷媒温度が異なる場合の冷媒温度変化は図7に示すようになり、凝縮器内で冷媒が過熱ガス状態である部分の温度分布が異なってくる。
Next, the correlation between the gas injection flow rate and the heating capacity will be described.
When the gas injection flow rate is increased, the refrigerant flow rate discharged from the compressor 3 increases as described above, while the discharge temperature of the compressor 3 decreases and the refrigerant temperature flowing into the condenser also decreases.
Looking at the heat exchange performance of the condenser, in general, the higher the temperature distribution in the heat exchanger, the greater the amount of heat exchange. The refrigerant temperature change when the refrigerant temperature at the condenser inlet is different at the same condensation temperature is as shown in FIG. 7, and the temperature distribution of the portion where the refrigerant is in the superheated gas state in the condenser is different.

凝縮器では冷媒が凝縮温度で二相状態にあるときの熱交換量が多くを占めるが、過熱ガス状態である部分の熱交換量も全体の20%〜30%程度存在し、熱交換量への影響は大きい。
インジェクション流量が多くなりすぎ、過熱ガス部分での冷媒温度の低下が著しいと、凝縮器での熱交換性能が低下し、暖房能力も低下する。上記のガスインジェクション流量と暖房能力の相関を表すと図8のようになり、暖房能力が最大となるガスインジェクション流量が存在する。
In the condenser, the heat exchange amount when the refrigerant is in the two-phase state at the condensation temperature occupies a large amount, but the heat exchange amount of the part that is in the superheated gas state is also about 20% to 30% of the total, and the heat exchange amount The impact of is great.
If the injection flow rate is excessively increased and the refrigerant temperature is significantly reduced in the superheated gas portion, the heat exchange performance in the condenser is lowered and the heating capacity is also lowered. The correlation between the gas injection flow rate and the heating capacity is shown in FIG. 8, and there is a gas injection flow rate at which the heating capacity is maximized.

次に、本実施の形態における第1内部熱交換器9の作用効果について説明する。
第1内部熱交換器9では、凝縮器を出た高圧液冷媒と圧縮機3の吸入冷媒が熱交換される。高圧液冷媒が第1内部熱交換器9にて冷却されることにより、蒸発器に流入する冷媒のエンタルピは低くなるので、蒸発器での冷媒エンタルピ差が拡大される。
従って、冷房運転時には冷房能力が増加する。
Next, the effect of the 1st internal heat exchanger 9 in this Embodiment is demonstrated.
In the first internal heat exchanger 9, the high-pressure liquid refrigerant exiting the condenser and the suction refrigerant of the compressor 3 are heat-exchanged. Since the high pressure liquid refrigerant is cooled by the first internal heat exchanger 9, the enthalpy of the refrigerant flowing into the evaporator is lowered, so that the refrigerant enthalpy difference in the evaporator is expanded.
Therefore, the cooling capacity increases during the cooling operation.

一方、圧縮機3に吸入される冷媒は加熱され、吸入温度が上昇する。これに伴い圧縮機3の吐出温度も上昇する。また圧縮機3の圧縮行程では、同じ昇圧を行う場合でも一般的に高温の冷媒を圧縮するほどより多くの仕事を必要とする。
従って、第1内部熱交換器9を設けることによる効率面での影響は、蒸発器エンタルピ差拡大による能力増加と、圧縮仕事の増加の両面が表れ、蒸発器エンタルピ差拡大による能力増加の影響が大きい場合には、装置の運転効率が上昇する。
On the other hand, the refrigerant sucked into the compressor 3 is heated and the suction temperature rises. Along with this, the discharge temperature of the compressor 3 also rises. Further, in the compression process of the compressor 3, even when the same pressure increase is performed, more work is generally required as the high-temperature refrigerant is compressed.
Therefore, the effect on the efficiency due to the provision of the first internal heat exchanger 9 shows both the increase in capacity due to the expansion of the evaporator enthalpy difference and the increase in compression work, and the influence of the increase in capacity due to the expansion of the evaporator enthalpy difference. If it is larger, the operating efficiency of the device increases.

次に、本実施の形態のように、第1内部熱交換器9による熱交換と、インジェクション回路13によるガスインジェクションを組み合わせた場合の効果について説明する。
第1内部熱交換器9による熱交換を行うと、圧縮機3吸入温度が上昇する。従って、インジェクションを行った場合の圧縮機3内部の変化においては、低圧から中間圧に昇圧された冷媒エンタルピ(図2、図3の点11)が高くなり、インジェクションされる冷媒と合流した後の冷媒エンタルピ(図2、図3の点12)も高くなる。
Next, the effect of combining heat exchange by the first internal heat exchanger 9 and gas injection by the injection circuit 13 as in the present embodiment will be described.
When heat exchange is performed by the first internal heat exchanger 9, the intake temperature of the compressor 3 increases. Therefore, in the change in the compressor 3 when the injection is performed, the refrigerant enthalpy (point 11 in FIGS. 2 and 3) increased from the low pressure to the intermediate pressure becomes higher, and after the merged with the injected refrigerant The refrigerant enthalpy (point 12 in FIGS. 2 and 3) also increases.

従って、圧縮機3の吐出エンタルピ(図2、図3の点1)も高くなり、圧縮機3の吐出温度は上昇する。そこで、第1内部熱交換器9による熱交換の有無に伴う、ガスインジェクション流量と暖房能力の相関の変化を表すと図9のようになる。
第1内部熱交換器9による熱交換が有る場合には、同一インジェクション量を行った場合の圧縮機3吐出温度は高くなるので、凝縮器入口の冷媒温度も高くなり、凝縮器熱交換量が増加し、暖房能力が増加する。従って暖房能力ピークとなるインジェクション流量が増加し、暖房能力のピーク値そのものも増加し、より多くの暖房能力を得ることができる。
Therefore, the discharge enthalpy (point 1 in FIGS. 2 and 3) of the compressor 3 is also increased, and the discharge temperature of the compressor 3 is increased. Therefore, FIG. 9 shows a change in the correlation between the gas injection flow rate and the heating capacity with or without heat exchange by the first internal heat exchanger 9.
When there is heat exchange by the first internal heat exchanger 9, since the discharge temperature of the compressor 3 when the same injection amount is performed is increased, the refrigerant temperature at the condenser inlet is also increased, and the condenser heat exchange amount is Increases heating capacity. Therefore, the injection flow rate at which the heating capacity reaches a peak increases, the peak value of the heating capacity itself increases, and more heating capacity can be obtained.

なお、第1内部熱交換器9が存在しない場合でも、第1膨張弁11の開度制御により、圧縮機3の吸入過熱度を上昇させて、圧縮機3の吐出温度を上昇させることができる。
しかし、この場合は、同時に蒸発器となる室外熱交換器12出口の冷媒過熱度も大きくなることから、室外熱交換器12の熱交換効率が低下する。
室外熱交換器12の熱交換効率が低下すると、同一熱交換量を得るためには、蒸発温度を低下させねばならず、低圧の低下する運転となる。
Even when the first internal heat exchanger 9 is not present, the suction superheat degree of the compressor 3 can be increased and the discharge temperature of the compressor 3 can be increased by controlling the opening degree of the first expansion valve 11. .
However, in this case, since the degree of refrigerant superheat at the outlet of the outdoor heat exchanger 12 that becomes the evaporator also increases, the heat exchange efficiency of the outdoor heat exchanger 12 decreases.
When the heat exchange efficiency of the outdoor heat exchanger 12 is lowered, in order to obtain the same heat exchange amount, the evaporation temperature must be lowered, and the operation is performed at a lower pressure.

低圧が低下すると、圧縮機3で吸入される冷媒流量も減少するため、このような運転を行うと、かえって暖房能力を低下させることになる。
逆にいうと、第1内部熱交換器9を用いると、蒸発器となる室外熱交換器12の出口の冷媒状態が適切な状態となり、熱交換効率のよい状態のまま、圧縮機3吐出温度を上昇させることができ、前記のような低圧の低下を回避し、暖房能力増加を容易に実現できる。
When the low pressure is lowered, the refrigerant flow rate sucked by the compressor 3 is also reduced. Therefore, when such an operation is performed, the heating capacity is lowered.
In other words, when the first internal heat exchanger 9 is used, the refrigerant state at the outlet of the outdoor heat exchanger 12 serving as an evaporator becomes an appropriate state, and the discharge temperature of the compressor 3 remains in a state with good heat exchange efficiency. Can be increased, a decrease in the low pressure as described above can be avoided, and an increase in heating capacity can be easily realized.

また、本実施の形態の回路構成では、高圧冷媒の一部をバイパスし減圧後、第2内部熱交換器10で過熱ガス化したあとインジェクションを行う構成をとっている。
従って、従来例のように気液分離器を用いて分離したガスをインジェクションする場合に比べ、制御や運転状態などに応じてインジェクション量が変化したときの冷媒量分布の変動が発生しないので、より安定した運転を実現できる。
In the circuit configuration of the present embodiment, a part of the high-pressure refrigerant is bypassed and decompressed, and after being superheated and gasified by the second internal heat exchanger 10, the injection is performed.
Therefore, compared to the case of injecting gas separated using a gas-liquid separator as in the conventional example, the refrigerant amount distribution does not change when the injection amount changes according to the control or operating state, etc. Stable operation can be realized.

なお、第3膨張弁14は圧縮機3の吐出温度が目標値となるように制御すると前述したが、この制御目標値は暖房能力が最大となるように設定する。
図9に示したように、ガスインジェクション流量−暖房能力−吐出温度の相関から、暖房能力最大となる吐出温度が存在するので、予めこの吐出温度を求めておいて目標値に設定する。なお、吐出温度の目標値は必ずしも一定値である必要は無く、運転条件や凝縮器などの機器の特性に応じて随時変更してもよい。
このように吐出温度制御を行うことで、ガスインジェクション量を暖房能力最大となるように制御できる。
Although the third expansion valve 14 has been described as being controlled so that the discharge temperature of the compressor 3 becomes the target value, the control target value is set so that the heating capacity is maximized.
As shown in FIG. 9, since there is a discharge temperature that maximizes the heating capacity based on the correlation between the gas injection flow rate, the heating capacity, and the discharge temperature, this discharge temperature is obtained in advance and set to the target value. Note that the target value of the discharge temperature is not necessarily a constant value, and may be changed as needed according to operating conditions and characteristics of equipment such as a condenser.
By performing the discharge temperature control in this way, the gas injection amount can be controlled to be the maximum heating capacity.

ガスインジェクション量については暖房能力最大となるようにするだけでなく、運転効率最大となるように制御することもできる。
冷凍空調装置起動時のように、多量の暖房能力を必要とする場合は能力最大に制御するが、装置を一定時間運転後、暖房により室温が上昇した場合などには、それほど多くの暖房能力を必要としなくなるので、このような場合には、効率最大となるように制御する。
The gas injection amount can be controlled not only to maximize the heating capacity but also to maximize the operating efficiency.
When a large amount of heating capacity is required, such as when the refrigeration air conditioner is activated, the maximum capacity is controlled. In such a case, control is performed to maximize efficiency.

インジェクション流量と暖房能力と運転効率の間には、図10に示すような相関があり、暖房能力最大となる場合に比べ、運転効率最大となるとき、インジェクション流量は少なく、吐出温度は高くなる。
暖房能力最大となるインジェクション流量では、吐出温度を低くしていることから、凝縮器の熱交換性能が低下していること、またインジェクション流量を多くするために、中間圧力が低くなり、インジェクション分を圧縮する圧縮仕事が多くなることにより、運転効率最大となる場合に比べ効率が低下する。
There is a correlation as shown in FIG. 10 between the injection flow rate, the heating capacity, and the operation efficiency. Compared to the maximum heating capacity, the injection flow rate is small and the discharge temperature is high when the operation efficiency is maximum.
At the injection flow rate at which the heating capacity is maximized, the discharge temperature is lowered, so that the heat exchange performance of the condenser is lowered, and in order to increase the injection flow rate, the intermediate pressure is lowered and the injection amount is reduced. By increasing the compression work to be compressed, the efficiency is reduced as compared with the case where the operation efficiency is maximized.

そこで、インジェクション回路13の第3膨張弁14で制御する吐出温度目標値として、暖房能力最大となる目標値だけでなく運転効率最大となる目標値も持ち、運転状況、例えば圧縮機3の運転容量や、室内機側空気温度の状況に応じて、暖房能力が必要とされるときは、暖房能力最大となる目標値に設定し、そうでない場合は運転効率最大となる目標値に設定する。
このような運転を行うことにより、多量の暖房能力を実現するとともに、効率の高い装置の運転を行うことができる。
Therefore, the discharge temperature target value controlled by the third expansion valve 14 of the injection circuit 13 has not only the target value that maximizes the heating capacity but also the target value that maximizes the operating efficiency, and the operating status, for example, the operating capacity of the compressor 3. If the heating capacity is required according to the indoor unit side air temperature, the target value is set to the maximum heating capacity, and if not, the target value is set to the maximum operating efficiency.
By performing such an operation, it is possible to realize a large amount of heating capacity and to operate a highly efficient apparatus.

また第1膨張弁11は圧縮機3の吸入過熱度が目標値となるように制御するとしたが、この制御により蒸発器となる熱交換器出口の過熱度を最適にでき、蒸発器での熱交換性能を高く確保するとともに、冷媒エンタルピ差も適度に確保するように運転することができ、高効率の運転を行うことができる。
このような運転となる蒸発器出口の過熱度は熱交換器の特性によって異なるが、概ね2℃前後であり、それから第1内部熱交換器9で冷媒が加熱されるので、圧縮機3の吸入過熱度の目標値はこの値より高くなり、例えば前述した10℃が目標値に設定される。
Further, the first expansion valve 11 is controlled so that the suction superheat degree of the compressor 3 becomes a target value, but this control can optimize the superheat degree at the outlet of the heat exchanger as an evaporator, and the heat in the evaporator. While ensuring high exchange performance, it can drive | operate so that a refrigerant | coolant enthalpy difference may also be ensured moderately, and a highly efficient driving | operation can be performed.
Although the degree of superheat at the outlet of the evaporator in such an operation varies depending on the characteristics of the heat exchanger, it is about 2 ° C., and since the refrigerant is heated by the first internal heat exchanger 9, the suction of the compressor 3 The target value of the superheat degree becomes higher than this value, and for example, the above-mentioned 10 ° C. is set as the target value.

従って、第1膨張弁11の制御としては、蒸発器出口の過熱度、暖房運転の場合は温度センサ16bと温度センサ16cの差温で求められる室外熱交換器12出口の過熱度が目標値、例えば前述した2℃になるように制御してもよい。
ただし、蒸発器出口の過熱度を直接制御する場合、その目標値が2℃程度と低い値である場合には過渡的に蒸発器出口が気液二相状態となり、過熱度が適切に検知できず制御が難しくなることが生じる。
Therefore, as the control of the first expansion valve 11, the superheat degree at the outlet of the evaporator, and in the case of heating operation, the superheat degree at the outlet of the outdoor heat exchanger 12 obtained by the difference temperature between the temperature sensor 16b and the temperature sensor 16c is the target value, For example, you may control so that it may become 2 degreeC mentioned above.
However, when directly controlling the degree of superheat at the outlet of the evaporator, if the target value is a low value of about 2 ° C, the evaporator outlet becomes a gas-liquid two-phase state transiently, and the degree of superheat can be detected appropriately. It becomes difficult to control.

圧縮機3の吸入過熱度で検知すると、目標値を高く設定できるとともに第1内部熱交換器9での加熱により、吸入が気液二相となって過熱度が適切に検知できないという状況は発生しないので、制御としては、より容易に行うことができ、安定した制御を行うことができる。   If the suction superheat degree of the compressor 3 is detected, the target value can be set high, and the situation where the superheat degree cannot be detected properly due to the gas-liquid two-phase suction due to the heating in the first internal heat exchanger 9 occurs. Therefore, control can be performed more easily and stable control can be performed.

また、第2膨張弁8は凝縮器となる室内熱交換器6出口の過冷却度が目標値となるように制御するとしたが、この制御により凝縮器での熱交換性能を高く確保するとともに、冷媒エンタルピ差も適度に確保するように運転することができ、高効率の運転を行うことができる。
このような運転となる凝縮器出口の過冷却度は熱交換器の特性によって異なるが概ね5〜10℃前後である。
In addition, the second expansion valve 8 is controlled so that the degree of supercooling at the outlet of the indoor heat exchanger 6 serving as a condenser becomes a target value, and this control ensures high heat exchange performance in the condenser, The operation can be performed so that the refrigerant enthalpy difference is appropriately secured, and a highly efficient operation can be performed.
The degree of supercooling at the outlet of the condenser for such operation varies depending on the characteristics of the heat exchanger, but is generally around 5 to 10 ° C.

なお、過冷却度の目標値はこの値より高く設定する、例えば10〜15℃前後に設定することによって、暖房能力を増加した運転も行うことができる。
そこで、運転状況に応じて、過冷却度の目標値を変更し、装置起動時は高めの過冷却度目標値で暖房能力確保、室温安定時は低めの過冷却度目標値で高効率運転を行うようにすることもできる。
In addition, the operation which increased the heating capability can also be performed by setting the target value of a supercooling degree higher than this value, for example, setting to about 10-15 degreeC.
Therefore, the target value of the degree of supercooling is changed according to the operating conditions, and the heating capacity is secured with a higher target value of supercooling when starting up the device, and high efficiency operation is performed with a lower target value of subcooling when the room temperature is stable. You can also do it.

なお、冷凍空調装置の冷媒としては、R410Aに限るものではなく、他の冷媒、HFC系冷媒であるR134aやR404A、R407C、自然冷媒であるCO2、HC系冷媒、アンモニア、空気、水などに用いることができる。特に冷媒としてCO2を用いた場合、蒸発器での冷媒エンタルピ差が小さく運転効率が低くなるという欠点に対して、本装置の構成として第1内部熱交換器9、第2内部熱交換器10により蒸発器エンタルピ差を拡大することができるので、より大きな効率改善を行うことができ、本装置の適用に好適である。   The refrigerant of the refrigerating and air-conditioning apparatus is not limited to R410A, but is used for other refrigerants, HFC-based refrigerants R134a, R404A, and R407C, natural refrigerants such as CO2, HC-based refrigerants, ammonia, air, and water. be able to. In particular, when CO2 is used as the refrigerant, the first internal heat exchanger 9 and the second internal heat exchanger 10 are used as a configuration of the present apparatus to deal with the disadvantage that the refrigerant enthalpy difference in the evaporator is small and the operation efficiency is low. Since the difference in the enthalpy of the evaporator can be enlarged, the efficiency can be further improved, which is suitable for application of the present apparatus.

また、CO2の場合には、凝縮温度が存在せず、放熱器となる高圧側熱交換器では流れに伴い温度低下する。従って、放熱器での熱交換量変化は、ある一定区間凝縮温度となり一定量の熱交換量が確保できるHFC系冷媒などとは異なり、入口温度の影響が大きくなる。
従って、本実施の形態のように、吐出温度を高くしながらインジェクション流量を増加できる構成とすることで、HFC系冷媒などより暖房能力の増加率が大きくなり、この面でもCO2冷媒は本装置の適用に好適である。
Further, in the case of CO2, there is no condensation temperature, and the temperature of the high-pressure side heat exchanger serving as a radiator decreases with the flow. Therefore, the change in the heat exchange amount in the radiator becomes a certain constant section condensation temperature, and the influence of the inlet temperature becomes larger, unlike an HFC refrigerant that can secure a constant amount of heat exchange.
Therefore, as in this embodiment, by adopting a configuration in which the injection flow rate can be increased while increasing the discharge temperature, the rate of increase in heating capacity is greater than that of HFC refrigerants and the like. Suitable for application.

また、第1内部熱交換器9、第2内部熱交換器10の配置位置は図1の構成に限るものではなく、上流下流の位置関係が反対であっても同様の効果を得ることができる。またインジェクション回路13を取り出す位置も図1の位置に限るものではなく、他の中間圧部分、および高圧液部から取り出せる位置であれば同様の効果を得ることができる。
なお、第3膨張弁14の制御安定性を考慮するとインジェクション回路13を取り出す位置としては、気液二相状態であるよりは完全に液となっている位置の方が望ましい。
Further, the arrangement positions of the first internal heat exchanger 9 and the second internal heat exchanger 10 are not limited to the configuration of FIG. 1, and the same effect can be obtained even if the upstream and downstream positional relationships are opposite. . Further, the position where the injection circuit 13 is taken out is not limited to the position shown in FIG. 1, and the same effect can be obtained as long as the position can be taken out from the other intermediate pressure part and the high pressure liquid part.
In consideration of the control stability of the third expansion valve 14, the position where the injection circuit 13 is taken out is preferably a position where the liquid is completely liquid rather than the gas-liquid two-phase state.

なお、本実施の形態では、第1膨張弁11、第3膨張弁8の間に第1内部熱交換器9、第2内部熱交換器10及びインジェクション回路13の取り出し位置を配置しているので、冷暖いずれの運転モードでも同様のインジェクションを行った運転を実施できる。
また、冷媒の飽和温度を凝縮器、蒸発器中間の冷媒温度センサで検知しているが、高低圧を検知する圧力センサを設け、計測された圧力値を換算して飽和温度を求めてもよい。
In the present embodiment, since the first internal heat exchanger 9, the second internal heat exchanger 10 and the injection circuit 13 are taken out between the first expansion valve 11 and the third expansion valve 8. The operation with the same injection can be performed in any of the cooling and heating operation modes.
Further, the refrigerant saturation temperature is detected by the refrigerant temperature sensor between the condenser and the evaporator. However, a pressure sensor for detecting high and low pressures may be provided, and the measured pressure value may be converted to obtain the saturation temperature. .

実施の形態2.
以下本発明の実施の形態2を図11に示す。図11は実施の形態2における冷凍空調装置の冷媒回路図であり、室外機内に中圧レシーバ17が設けられ、その内部に圧縮機3の吸入配管が貫通している。
この貫通部分の冷媒と中圧レシーバ17内の冷媒が熱交換可能な構成となっており、実施の形態1における第1内部熱交換器9と同じ機能を実現する。
Embodiment 2. FIG.
A second embodiment of the present invention is shown in FIG. FIG. 11 is a refrigerant circuit diagram of the refrigerating and air-conditioning apparatus according to Embodiment 2, in which an intermediate pressure receiver 17 is provided in the outdoor unit, and a suction pipe of the compressor 3 passes therethrough.
The refrigerant in the penetrating portion and the refrigerant in the intermediate pressure receiver 17 are configured to exchange heat, and realize the same function as the first internal heat exchanger 9 in the first embodiment.

本形態における作用効果は、中圧レシーバ17を除き、実施の形態1と同じであるので、その部分については説明を省略する。中圧レシーバ17では、暖房運転時には室内交換器6出口の気液二相冷媒が流入し、中圧レシーバ17内で冷却され液となって流出する。冷房運転時には第1膨張弁11を出た気液二相冷媒が流入し、中圧レシーバ17内で冷却され液となって流出する。   Since the operational effects in this embodiment are the same as those in the first embodiment except for the intermediate pressure receiver 17, the description thereof is omitted. In the intermediate pressure receiver 17, the gas-liquid two-phase refrigerant at the outlet of the indoor exchanger 6 flows in during heating operation, and is cooled in the intermediate pressure receiver 17 and flows out as liquid. During the cooling operation, the gas-liquid two-phase refrigerant that has exited the first expansion valve 11 flows in and is cooled in the intermediate pressure receiver 17 and flows out as liquid.

中圧レシーバ17内での熱交換は、主に気液二相冷媒のうちガス冷媒が吸入配管と触れて凝縮液化して熱交換される。従って、中圧レシーバ17内に滞留する液冷媒量が少ないほど、ガス冷媒と吸入配管が接触する面積が多くなり、熱交換量は増加する。逆に、中圧レシーバ17内に滞留する液冷媒量が多いと、ガス冷媒と吸入配管が接触する面積が少なくり、熱交換量は減少する。   The heat exchange in the intermediate pressure receiver 17 is mainly performed by exchanging the gas refrigerant out of the gas-liquid two-phase refrigerant into contact with the suction pipe to be condensed and liquefied. Therefore, the smaller the amount of liquid refrigerant that stays in the intermediate pressure receiver 17, the more the area where the gas refrigerant and the suction pipe come into contact with each other, and the amount of heat exchange increases. On the contrary, when the amount of liquid refrigerant staying in the intermediate pressure receiver 17 is large, the area where the gas refrigerant and the suction pipe are in contact with each other decreases, and the amount of heat exchange decreases.

このように中圧レシーバ17を備えることで以下の効果を持つ。
まず、中圧レシーバ17の出口は液となるので、暖房運転時に第3膨張弁14に流入する冷媒は、必ず液冷媒となるので、第3膨張弁14の流量特性が安定し、制御安定性が確保され、安定した装置運転を行うことができる。
また中圧レシーバ17内で熱交換を行うことで中圧レシーバ17の圧力が安定的になり、第3膨張弁14の入口圧力が安定し、インジェクション回路13に流れる冷媒流量が安定するという効果もある。例えば負荷変動などがあり、高圧が変動したりすると、それに伴い中圧レシーバ17内の圧力変動が生じるが、中圧レシーバ17内の熱交換により圧力変動が抑制される。
By providing the intermediate pressure receiver 17 as described above, the following effects are obtained.
First, since the outlet of the intermediate pressure receiver 17 is liquid, the refrigerant flowing into the third expansion valve 14 during the heating operation is necessarily liquid refrigerant, so that the flow rate characteristic of the third expansion valve 14 is stable and control stability is achieved. Is ensured, and stable device operation can be performed.
In addition, heat exchange in the intermediate pressure receiver 17 stabilizes the pressure of the intermediate pressure receiver 17, stabilizes the inlet pressure of the third expansion valve 14, and stabilizes the flow rate of the refrigerant flowing through the injection circuit 13. is there. For example, when there is a load fluctuation or the like and the high pressure fluctuates, a pressure fluctuation in the intermediate pressure receiver 17 occurs accordingly, but the pressure fluctuation is suppressed by heat exchange in the intermediate pressure receiver 17.

負荷が増加し、高圧が上昇すると中圧レシーバ17内の圧力も上昇するが、そのときには、低圧との圧力差が広がり、中圧レシーバ17内の熱交換器での温度差も広がるので熱交換量が増加する。熱交換量が増加すると、中圧レシーバ17に流入する気液二相冷媒のうちのガス冷媒が凝縮する量が多くなるので、圧力が上がりにくくなり、中圧レシーバ17の圧力上昇が抑制される。   When the load increases and the high pressure rises, the pressure in the intermediate pressure receiver 17 also rises. At that time, the pressure difference from the low pressure widens and the temperature difference in the heat exchanger in the intermediate pressure receiver 17 also widens, so heat exchange. The amount increases. When the amount of heat exchange increases, the amount of gas refrigerant in the gas-liquid two-phase refrigerant flowing into the intermediate pressure receiver 17 condenses, so that the pressure is difficult to increase and the pressure increase of the intermediate pressure receiver 17 is suppressed. .

逆に、負荷が減少し、高圧が低下すると中圧レシーバ17内の圧力も低下するが、そのときには、低圧との圧力差が狭まり、中圧レシーバ17内の熱交換器での温度差も狭まるので熱交換量が減少する。熱交換量が減少すると、中圧レシーバ17に流入する気液二相冷媒のうちのガス冷媒が凝縮する量が少なくなるので、圧力が下がりにくくなり、中圧レシーバ17の圧力は低下が抑制される。
このように、中圧レシーバ17内で熱交換を行うことにより、運転状態変動に伴う熱交換量変動が自律的に発生し、その結果として中圧レシーバ17内の圧力変動が抑制される。
Conversely, when the load decreases and the high pressure decreases, the pressure in the intermediate pressure receiver 17 also decreases. At that time, the pressure difference from the low pressure is narrowed, and the temperature difference in the heat exchanger in the intermediate pressure receiver 17 is also narrowed. As a result, the amount of heat exchange decreases. When the amount of heat exchange decreases, the amount of gas refrigerant in the gas-liquid two-phase refrigerant flowing into the intermediate pressure receiver 17 is reduced, so that the pressure is less likely to decrease, and the pressure of the intermediate pressure receiver 17 is suppressed from decreasing. The
Thus, by performing heat exchange in the intermediate pressure receiver 17, the heat exchange amount variation accompanying the operation state variation occurs autonomously, and as a result, the pressure variation in the intermediate pressure receiver 17 is suppressed.

また、中圧レシーバ17内で熱交換を行うことで装置運転そのものが安定するという効果もある。例えば低圧側の状態が変動し、蒸発器である室外熱交換器12の出口の冷媒過熱度が大きくなった場合には、中圧レシーバ17内での熱交換の際の温度差が減少するため、熱交換量が減少し、ガス冷媒が凝縮されにくくなるので、中圧レシーバ17内のガス冷媒量が増加し、液冷媒量が減少する。
減少した分の液冷媒量は、室外熱交換器12に移動し、室外熱交換器12内の液冷媒量が増加することから、室外熱交換器12出口の冷媒過熱度が大きくなることが抑制され、装置の運転変動が抑制される。
Moreover, there is an effect that the operation of the apparatus itself is stabilized by exchanging heat in the intermediate pressure receiver 17. For example, when the state on the low pressure side fluctuates and the refrigerant superheat degree at the outlet of the outdoor heat exchanger 12 that is an evaporator becomes large, the temperature difference during heat exchange in the intermediate pressure receiver 17 decreases. Since the amount of heat exchange is reduced and the gas refrigerant is less likely to be condensed, the amount of gas refrigerant in the intermediate pressure receiver 17 is increased and the amount of liquid refrigerant is reduced.
The reduced amount of liquid refrigerant moves to the outdoor heat exchanger 12 and the amount of liquid refrigerant in the outdoor heat exchanger 12 increases, so that the refrigerant superheat degree at the outlet of the outdoor heat exchanger 12 is prevented from increasing. Thus, fluctuations in the operation of the apparatus are suppressed.

逆に、低圧側の状態が変動し、蒸発器である室外熱交換器12出口の冷媒過熱度が小さくなった場合には、中圧レシーバ17内での熱交換の際の温度差が増加するため、熱交換量が増加し、ガス冷媒が凝縮されやすくなるので、中圧レシーバ17内のガス冷媒量が減少し、液冷媒量が増加する。この分の液冷媒量は、室外熱交換器12から移動することになり、室外熱交換器12内の液冷媒量が減少することから、室外熱交換器12出口の冷媒過熱度が小さくなることが抑制され、装置の運転変動が抑制される。
この過熱度変動を抑制する作用も、中圧レシーバ17内で熱交換を行うことにより、運転状態変動に伴う熱交換量変動が自律的に発生することによって生じている。
Conversely, when the state on the low pressure side fluctuates and the degree of refrigerant superheating at the outlet of the outdoor heat exchanger 12 that is an evaporator becomes small, the temperature difference during heat exchange in the intermediate pressure receiver 17 increases. Therefore, the amount of heat exchange increases and the gas refrigerant is easily condensed, so that the amount of gas refrigerant in the intermediate pressure receiver 17 decreases and the amount of liquid refrigerant increases. This amount of liquid refrigerant moves from the outdoor heat exchanger 12, and the amount of liquid refrigerant in the outdoor heat exchanger 12 decreases, so that the degree of refrigerant superheat at the outlet of the outdoor heat exchanger 12 decreases. Is suppressed, and fluctuations in the operation of the apparatus are suppressed.
The effect of suppressing the fluctuation in superheat is also caused by the fact that the heat exchange amount in the intermediate pressure receiver 17 undergoes heat exchange, whereby the heat exchange amount fluctuation accompanying the operation state fluctuation occurs autonomously.

以上のように、実施の形態1における第1内部熱交換器9での熱交換を中圧レシーバ17で行う構成とすることで、装置の運転変動が起きても、自律的な熱交換量変動により変動を抑制し、装置運転を安定的に行うことができる。   As described above, the heat exchange in the first internal heat exchanger 9 according to the first embodiment is performed by the intermediate pressure receiver 17, so that even if the apparatus fluctuates, the heat exchange amount fluctuates autonomously. Therefore, the fluctuation can be suppressed and the apparatus can be operated stably.

なお、中圧レシーバ17で熱交換を行う構造であるが、中圧レシーバ17内の冷媒と熱交換する構成であればどのような構成をとっても同様の効果を得ることができる。例えば、中圧レシーバ17容器外周に圧縮機3の吸入配管を接触させて熱交換させる構成を用いてもよい。
また、インジェクション回路13に供給する冷媒を中圧レシーバ17底部から供給してもよい。この場合には、冷暖房の各運転で、第3膨張弁14に液冷媒が流入することになるので、冷暖いずれの運転においても第3膨張弁14の流量特性が安定し、制御安定性が確保される。
In addition, although it is the structure which heat-exchanges with the intermediate pressure receiver 17, if it is the structure which heat-exchanges with the refrigerant | coolant in the intermediate pressure receiver 17, what kind of structure will be able to acquire the same effect. For example, a configuration in which the suction pipe of the compressor 3 is brought into contact with the outer periphery of the container of the intermediate pressure receiver 17 to perform heat exchange may be used.
Further, the refrigerant supplied to the injection circuit 13 may be supplied from the bottom of the intermediate pressure receiver 17. In this case, since the liquid refrigerant flows into the third expansion valve 14 in each operation of cooling and heating, the flow rate characteristic of the third expansion valve 14 is stable in both the cooling and heating operations, and control stability is ensured. Is done.

本発明に係る実施の形態1の冷凍空調装置の冷媒回路図である。It is a refrigerant circuit figure of the refrigerating and air-conditioning apparatus of Embodiment 1 which concerns on this invention. 同冷凍空調装置の暖房運転時の運転状況を表したPH線図である。It is PH diagram showing the driving | running state at the time of the heating operation of the refrigerating air conditioner. 同冷凍空調装置の冷房運転時の運転状況を表したPH線図である。It is PH diagram showing the driving | running state at the time of air_conditionaing | cooling operation of the same refrigeration air conditioner. 同冷凍空調装置の暖房運転時の制御動作を示すフロー図である。It is a flow figure showing control operation at the time of heating operation of the refrigerating air-conditioner. 同冷凍空調装置の冷房運転時の制御動作を示すフロー図である。It is a flowchart which shows the control action at the time of the air_conditionaing | cooling operation of the same refrigeration air conditioner. 同冷凍空調装置のガスインジェクション実施時の運転状況を表したPH線図である。It is a PH diagram showing the driving | running state at the time of gas injection implementation of the refrigerating air conditioner. 同冷凍空調装置のガスインジェクション実施時の凝縮器の温度変化を表した図である。It is a figure showing the temperature change of the condenser at the time of gas injection implementation of the refrigerating air conditioner. 同冷凍空調装置のガスインジェクション流量変化時の運転特性を表した図である。It is a figure showing the operation characteristic at the time of the gas injection flow rate change of the refrigerating air-conditioner. 同冷凍空調装置の第1内部熱交換器の有無による運転特性の違いを表した図である。It is a figure showing the difference in the operation characteristic by the presence or absence of the 1st internal heat exchanger of the refrigerating air-conditioning apparatus. 同冷凍空調装置のガスインジェクション流量変化時の運転特性を表した別の図である。It is another figure showing the operation characteristic at the time of the gas injection flow rate change of the refrigeration air conditioner. 本発明に係る実施の形態2の冷凍空調装置の冷媒回路図である。It is a refrigerant circuit figure of the refrigerating and air-conditioning apparatus of Embodiment 2 which concerns on this invention.

符号の説明Explanation of symbols

1 室外機、2 室内機、3 圧縮機、4 四方弁、5 ガス管、6 室内熱交換器、7 液管、8 第2の膨張弁、9 第1内部熱交換器、10 第2内部熱交換器、11 第1の膨張弁、12 室外熱交換器、13 インジェクション回路、14 インジェクション用の膨張弁、15 計測制御装置。
DESCRIPTION OF SYMBOLS 1 Outdoor unit, 2 Indoor unit, 3 Compressor, 4 Four way valve, 5 Gas pipe, 6 Indoor heat exchanger, 7 Liquid pipe, 8 2nd expansion valve, 9 1st internal heat exchanger, 10 2nd internal heat Exchanger, 11 1st expansion valve, 12 outdoor heat exchanger, 13 injection circuit, 14 expansion valve for injection, 15 measurement control apparatus.

Claims (23)

圧縮機、室内熱交換器、第1の減圧装置、室外熱交換器を環状に接続し、前記室内熱交換器から温熱を供給する冷凍空調装置において、
前記室内熱交換器と前記第1の減圧装置との間の冷媒と、前記室外熱交換器と前記圧縮機との間の冷媒とを熱交換する第1の内部熱交換器と、
前記室内熱交換器と前記第1の減圧装置との間の冷媒を、一部バイパスして前記圧縮機内の圧縮室にインジェクションするインジェクション回路と、
該インジェクション回路に設けられたインジェクション用減圧装置と、
該インジェクション用減圧装置で減圧された冷媒と前記室内熱交換器と前記第1の減圧装置との間の冷媒とを熱交換する第2の内部熱交換器と、
を備えたことを特徴とする冷凍空調装置。
In the refrigerating and air-conditioning apparatus for connecting the compressor, the indoor heat exchanger, the first pressure reducing device, and the outdoor heat exchanger in an annular shape and supplying the heat from the indoor heat exchanger,
A first internal heat exchanger that exchanges heat between the refrigerant between the indoor heat exchanger and the first pressure reducing device and the refrigerant between the outdoor heat exchanger and the compressor;
An injection circuit for partially bypassing the refrigerant between the indoor heat exchanger and the first decompressor and injecting the refrigerant into the compression chamber in the compressor;
An injection decompression device provided in the injection circuit;
A second internal heat exchanger that exchanges heat between the refrigerant decompressed by the injection decompression device and the refrigerant between the indoor heat exchanger and the first decompression device;
A refrigeration air conditioner characterized by comprising:
前記室内熱交換器と前記第1の内部熱交換器との間に第2の減圧装置を備えたことを特徴とする請求項1記載の冷凍空調装置。   The refrigerating and air-conditioning apparatus according to claim 1, further comprising a second decompression device between the indoor heat exchanger and the first internal heat exchanger. 前記第1の内部熱交換器は、前記室内熱交換器と前記第1の減圧装置との間に設けられ、循環する冷媒を貯留して前記室外熱交換器と圧縮機との間の冷媒と熱交換するレシーバに備えられることを特徴とする請求項1又は2記載の冷凍空調装置。   The first internal heat exchanger is provided between the indoor heat exchanger and the first pressure reducing device, stores a circulating refrigerant, and stores a refrigerant between the outdoor heat exchanger and the compressor. The refrigerating and air-conditioning apparatus according to claim 1, wherein the refrigerating and air-conditioning apparatus is provided in a receiver that performs heat exchange. 前記第1の減圧装置により、前記圧縮機吸入の冷媒過熱度若しくは前記室外熱交換器の出口の冷媒過熱度が所定値となるように制御する制御装置を備えたことを特徴とする請求項1〜3のいずれかに記載の冷凍空調装置。   2. The control apparatus according to claim 1, further comprising: a control device configured to control the refrigerant superheat degree at the compressor suction or the refrigerant superheat degree at the outlet of the outdoor heat exchanger to be a predetermined value by the first pressure reducing device. Refrigeration air conditioner in any one of -3. 前記インジェクション用減圧装置により、前記圧縮機出口の冷媒吐出温度もしくは前記圧縮機出口の冷媒過熱度が所定値となるように制御する制御装置を備えたことを特徴とする請求項1〜3のいずれかに記載の冷凍空調装置。   4. The control device according to claim 1, further comprising: a control device configured to control the refrigerant discharge temperature at the compressor outlet or the refrigerant superheat degree at the compressor outlet to a predetermined value by the injection decompression device. A refrigeration air conditioner according to claim 1. 前記第2の減圧装置により、前記室内熱交換器出口の冷媒過冷却度が所定値となるように制御する制御装置を備えたことを特徴とする請求項2〜3のいずれかに記載の冷凍空調装置。   The refrigeration according to any one of claims 2 to 3, further comprising a control device that controls the degree of refrigerant supercooling at the outlet of the indoor heat exchanger to a predetermined value by the second decompression device. Air conditioner. 前記第1の減圧装置により、前記圧縮機吸入の冷媒過熱度若しくは前記室外熱交換器の出口の冷媒過熱度が所定値となるように制御し、前記インジェクション用減圧装置により、前記圧縮機出口の冷媒吐出温度もしくは前記圧縮機出口の冷媒過熱度が所定値となるように制御し、前記第2の減圧装置により、前記室内熱交換器出口の冷媒過冷却度が所定値となるように制御する制御装置を備えたことを特徴とする請求項2〜3のいずれかに記載の冷凍空調装置。   The first decompressor controls the refrigerant superheat degree of the compressor suction or the refrigerant superheat degree at the outlet of the outdoor heat exchanger to be a predetermined value, and the injection decompressor reduces the compressor outlet temperature. The refrigerant discharge temperature or the refrigerant superheat degree at the compressor outlet is controlled to be a predetermined value, and the second pressure reducing device is used to control the refrigerant supercooling degree at the indoor heat exchanger outlet to be a predetermined value. The refrigerating and air-conditioning apparatus according to any one of claims 2 to 3, further comprising a control device. 圧縮機、室外熱交換器、第1の減圧装置、室内熱交換器を環状に接続し、前記室内熱交換器から冷熱を供給する冷凍空調装置において、
前記室外熱交換器と前記第1の減圧装置との間の冷媒と、前記室内熱交換器と前記圧縮機との間の冷媒とを熱交換する第1の内部熱交換器と、
前記室外熱交換器と前記第1の減圧装置との間の冷媒を、一部バイパスして前記圧縮機内の圧縮室にインジェクションするインジェクション回路と、
該インジェクション回路に設けられたインジェクション用減圧装置と、
該インジェクション用減圧装置で減圧された冷媒と前記室内熱交換器と前記第1の減圧装置との間の冷媒とを熱交換する第2の内部熱交換器と、
を備えたことを特徴とする冷凍空調装置。
In the refrigerating and air-conditioning apparatus for connecting the compressor, the outdoor heat exchanger, the first pressure reducing device, and the indoor heat exchanger in an annular shape and supplying cold from the indoor heat exchanger,
A first internal heat exchanger that exchanges heat between the refrigerant between the outdoor heat exchanger and the first pressure reducing device and the refrigerant between the indoor heat exchanger and the compressor;
An injection circuit for partially bypassing the refrigerant between the outdoor heat exchanger and the first pressure reducing device and injecting the refrigerant into the compression chamber in the compressor;
An injection decompression device provided in the injection circuit;
A second internal heat exchanger that exchanges heat between the refrigerant decompressed by the injection decompression device and the refrigerant between the indoor heat exchanger and the first decompression device;
A refrigeration air conditioner characterized by comprising:
前記室外熱交換器と前記第2の内部熱交換器との間に第2の減圧装置を備えたことを特徴とする請求項8記載の冷凍空調装置。   The refrigerating and air-conditioning apparatus according to claim 8, further comprising a second pressure reducing device between the outdoor heat exchanger and the second internal heat exchanger. 前記第1の内部熱交換器は、前記室外熱交換器と前記第1の減圧装置との間に設けられ、循環する冷媒を貯留して前記室内熱交換器と圧縮機との間の冷媒と熱交換するレシーバに備えられることを特徴とする請求項8又は9記載の冷凍空調装置。   The first internal heat exchanger is provided between the outdoor heat exchanger and the first pressure reducing device, stores a circulating refrigerant, and stores a refrigerant between the indoor heat exchanger and the compressor. The refrigerating and air-conditioning apparatus according to claim 8 or 9, wherein the refrigerating and air-conditioning apparatus is provided in a receiver for heat exchange. 前記第1の減圧装置により、前記圧縮機吸入の冷媒過熱度若しくは前記室内熱交換器出口の冷媒過熱度が所定値となるように制御する制御装置を備えたことを特徴とする請求項8〜10のいずれかに記載の冷凍空調装置。   The control apparatus which controls by the said 1st pressure reduction device so that the refrigerant | coolant superheat degree of the said compressor suction | inhalation or the refrigerant | coolant superheat degree of the said indoor heat exchanger exit may become predetermined value. The refrigeration air conditioner according to any one of 10. 前記インジェクション用減圧装置により、前記圧縮機出口の冷媒吐出温度もしくは前記圧縮機出口の冷媒過熱度が所定値となるように制御する制御装置を備えたことを特徴とする請求項8〜10のいずれかに記載の冷凍空調装置。   11. The control device according to claim 8, further comprising a control device configured to control the refrigerant discharge temperature at the compressor outlet or the refrigerant superheat degree at the compressor outlet to a predetermined value by the injection decompression device. A refrigeration air conditioner according to claim 1. 前記第2の減圧装置により、前記室外熱交換器出口の冷媒過冷却度が所定値となるように制御する制御装置を備えたことを特徴とする請求項9〜10のいずれかに記載の冷凍空調装置。   The refrigeration according to any one of claims 9 to 10, further comprising a control device that controls the refrigerant supercooling degree at the outlet of the outdoor heat exchanger to a predetermined value by the second decompression device. Air conditioner. 前記第1の減圧装置により、前記圧縮機吸入の冷媒過熱度若しくは前記室内熱交換器出口の冷媒過熱度が所定値となるように制御し、前記インジェクション用減圧装置により、前記圧縮機出口の冷媒吐出温度もしくは前記圧縮機出口の冷媒過熱度が所定値となるように制御し、前記第2の減圧装置により、前記室外熱交換器出口の冷媒過冷却度が所定値となるように制御する制御装置を備えたことを特徴とする請求項9〜10のいずれかに記載の冷凍空調装置。   The first pressure reducing device controls the refrigerant superheat degree of the compressor suction or the refrigerant superheat degree of the indoor heat exchanger outlet to a predetermined value, and the injection pressure reducing device controls the refrigerant at the compressor outlet. Control for controlling the discharge temperature or the degree of refrigerant superheating at the compressor outlet to be a predetermined value, and controlling the degree of refrigerant supercooling at the outlet of the outdoor heat exchanger to be a predetermined value by the second decompression device The refrigerating and air-conditioning apparatus according to any one of claims 9 to 10, further comprising an apparatus. 圧縮機、暖房と冷房の運転切換を行う四方弁、室内熱交換器、第2減圧装置、第1減圧装置、室外交換器を備え、前記四方弁を暖房運転に切換えたときに冷媒が前記圧縮機、前記四方弁、前記室内熱交換器、前記第2減圧装置、前記第1減圧装置、前記室外熱交換器、前記圧縮機と循環し、前記室内熱交換器から温熱を供給し、前記四方弁を冷房運転に切換えたときに冷媒が前記圧縮機、前記四方弁、前記室外熱交換器、前記第1減圧装置、前記第2減圧装置、前記室内熱交換器、前記圧縮機と循環し、前記室内熱交換器から冷熱を供給するようにした冷凍空調装置において、
前記暖房運転のときに前記室内熱交換器と前記第1の減圧装置との間の冷媒と、前記室外熱交換器と前記圧縮機との間の冷媒とを熱交換し、前記冷房運転のときに前記室外熱交換器と前記第2の減圧装置との間の冷媒と、前記室内熱交換器と前記圧縮機との間の冷媒とを熱交換する第1の内部熱交換器と、
前記暖房運転のときに前記室内熱交換器と前記第1の減圧装置との間の冷媒を一部バイパスして前記圧縮機内の圧縮室にインジェクションし、前記冷房運転のときに前記室外熱交換器と前記第2の減圧装置との間の冷媒を一部バイパスして前記圧縮機内の圧縮室にインジェクションするインジェクション回路と、
該インジェクション回路に設けられたインジェクション用減圧装置と、
前記暖房運転のときに前記インジェクション用減圧装置で減圧された冷媒と前記室内熱交換器と前記第1の減圧装置との間の冷媒とを熱交換し、前記冷房運転のときに前記インジェクション用減圧装置で減圧された冷媒と前記室外熱交換器と前記第2の減圧装置との間の冷媒とを熱交換する第2の内部熱交換器と、
を備えたことを特徴とする冷凍空調装置。
A compressor, a four-way valve for switching between heating and cooling, an indoor heat exchanger, a second pressure reducing device, a first pressure reducing device, and an outdoor exchanger, and the refrigerant is compressed when the four-way valve is switched to heating operation. The four-way valve, the indoor heat exchanger, the second pressure reducing device, the first pressure reducing device, the outdoor heat exchanger, the compressor, and the hot water from the indoor heat exchanger. When the valve is switched to cooling operation, the refrigerant circulates with the compressor, the four-way valve, the outdoor heat exchanger, the first pressure reducing device, the second pressure reducing device, the indoor heat exchanger, the compressor, In the refrigeration air conditioner configured to supply cold from the indoor heat exchanger,
During the cooling operation, heat is exchanged between the refrigerant between the indoor heat exchanger and the first decompressor and the refrigerant between the outdoor heat exchanger and the compressor during the heating operation. A first internal heat exchanger that exchanges heat between the refrigerant between the outdoor heat exchanger and the second decompression device and the refrigerant between the indoor heat exchanger and the compressor,
During the heating operation, the refrigerant between the indoor heat exchanger and the first pressure reducing device is partially bypassed and injected into the compression chamber in the compressor, and during the cooling operation, the outdoor heat exchanger And an injection circuit for partially bypassing the refrigerant between the second decompression device and injecting into the compression chamber in the compressor;
An injection decompression device provided in the injection circuit;
Heat exchange is performed between the refrigerant decompressed by the injection decompression device during the heating operation and the refrigerant between the indoor heat exchanger and the first decompression device, and the injection decompression during the cooling operation. A second internal heat exchanger for exchanging heat between the refrigerant decompressed by the apparatus, the refrigerant between the outdoor heat exchanger and the second decompression device;
A refrigeration air conditioner characterized by comprising:
前記第1の内部熱交換器は、前記第1の減圧装置と前記第2の減圧装置との間に設けられ、循環する冷媒を貯留して前記暖房運転のときに前記室外熱交換器と前記圧縮機との間の冷媒と熱交換し、前記冷房運転のときに前記室内熱交換器と前記圧縮機との間の冷媒と熱交換するレシーバであることを特徴とする請求項15記載の冷凍空調装置。   The first internal heat exchanger is provided between the first decompression device and the second decompression device, stores the circulating refrigerant, and performs the outdoor heat exchanger and the 16. The refrigeration according to claim 15, wherein the refrigeration is a receiver that exchanges heat with a refrigerant between the compressor and heat exchange with the refrigerant between the indoor heat exchanger and the compressor during the cooling operation. Air conditioner. 前記暖房運転のときに、前記第1の減圧装置により、前記圧縮機吸入の冷媒過熱度若しくは前記室外熱交換器の出口の冷媒過熱度が所定値となるように制御する制御装置を備えたことを特徴とする請求項15又は16記載の冷凍空調装置。   A controller for controlling the refrigerant superheating degree of the compressor suction or the refrigerant superheating degree of the outlet of the outdoor heat exchanger to be a predetermined value by the first pressure reducing device during the heating operation; The refrigeration air conditioner according to claim 15 or 16. 前記暖房運転のときに、前記第2の減圧装置により、前記室内熱交換器出口の冷媒冷却度が所定値となるように制御する制御装置を備えたことを特徴とする請求項15又は16記載の冷凍空調装置。   17. The control device according to claim 15, further comprising a control device configured to control the refrigerant cooling degree at the outlet of the indoor heat exchanger to a predetermined value by the second decompression device during the heating operation. Refrigeration air conditioner. 前記冷房運転のときに、前記第1の減圧装置により、前記室外熱交換器の出口の冷媒過冷却度が所定値となるように制御する制御装置を備えたことを特徴とする請求項15又は16記載の冷凍空調装置。   16. The apparatus according to claim 15, further comprising a control device that controls the refrigerant supercooling degree at the outlet of the outdoor heat exchanger to be a predetermined value by the first pressure reducing device during the cooling operation. 16. The refrigeration air conditioner according to 16. 前記冷房運転のときに、前記第2の減圧装置により、前記圧縮機吸入の冷媒過熱度若しくは前記室内熱交換器の出口の冷媒過熱度が所定値となるように制御する制御装置を備えたことを特徴とする請求項15又は16記載の冷凍空調装置。   A controller for controlling the refrigerant superheat degree of the compressor suction or the refrigerant superheat degree at the outlet of the indoor heat exchanger to be a predetermined value by the second pressure reducing device during the cooling operation; The refrigeration air conditioner according to claim 15 or 16. 前記インジェクション用減圧装置により、前記圧縮機出口の冷媒吐出温度もしくは前記圧縮機出口の冷媒過熱度が所定値となるように制御する制御装置を備えたことを特徴とする請求項15又は16記載の冷凍空調装置。   17. The control device according to claim 15, further comprising a control device configured to control the refrigerant discharge temperature at the compressor outlet or the refrigerant superheat degree at the compressor outlet to a predetermined value by the injection decompression device. Refrigeration air conditioner. 前記暖房運転のときに、前記第1の減圧装置により、前記圧縮機吸入の冷媒過熱度若しくは前記室外熱交換器の出口の冷媒過熱度が所定値となるように制御すると共に、前記第2の減圧装置により、前記室内熱交換器出口の冷媒冷却度が所定値となるように制御し、
前記冷房運転のときに、前記第1の減圧装置により、前記室外熱交換器の出口の冷媒過冷却度が所定値となるように制御すると共に前記第2の減圧装置により、前記圧縮機吸入の冷媒過熱度若しくは前記室内熱交換器の出口の冷媒過熱度が所定値となるように制御し、前記暖房運転又は冷房運転のいずれのときにも前記インジェクション用減圧装置により、前記圧縮機出口の冷媒吐出温度もしくは前記圧縮機出口の冷媒過熱度が所定値となるように制御する制御装置を備えたことを特徴とする請求項15又は16のいずれかに記載の冷凍空調装置。
During the heating operation, the first pressure reducing device controls the refrigerant superheat degree of the compressor suction or the refrigerant superheat degree of the outlet of the outdoor heat exchanger to be a predetermined value, and the second By controlling the refrigerant cooling degree at the outlet of the indoor heat exchanger to a predetermined value by the decompression device,
During the cooling operation, the first pressure reducing device controls the refrigerant supercooling degree at the outlet of the outdoor heat exchanger to a predetermined value, and the second pressure reducing device controls the suction of the compressor. The refrigerant superheat degree or the refrigerant superheat degree at the outlet of the indoor heat exchanger is controlled to be a predetermined value, and the refrigerant at the compressor outlet is controlled by the injection decompression device in both the heating operation and the cooling operation. The refrigerating and air-conditioning apparatus according to any one of claims 15 and 16, further comprising a control device that controls the discharge temperature or the refrigerant superheat degree at the compressor outlet to be a predetermined value.
前記冷媒として二酸化炭素を用いたことを特徴とする請求項1〜22のいずれかに記載の冷凍空調装置。   The refrigerating and air-conditioning apparatus according to any one of claims 1 to 22, wherein carbon dioxide is used as the refrigerant.
JP2004300022A 2004-10-14 2004-10-14 Refrigerating air conditioner Pending JP2006112708A (en)

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