JP2006118826A - Oil quantity determining device, refrigeration device and its control method - Google Patents

Oil quantity determining device, refrigeration device and its control method Download PDF

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JP2006118826A
JP2006118826A JP2004309706A JP2004309706A JP2006118826A JP 2006118826 A JP2006118826 A JP 2006118826A JP 2004309706 A JP2004309706 A JP 2004309706A JP 2004309706 A JP2004309706 A JP 2004309706A JP 2006118826 A JP2006118826 A JP 2006118826A
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compressor
oil
temperature
pressure
pipe
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JP4390679B2 (en
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Taku Sekine
卓 関根
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Sanyo Electric Co Ltd
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2400/00—General 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
    • F25B2400/07—Details of compressors or related parts
    • F25B2400/075—Details of compressors or related parts with parallel compressors
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2700/00—Sensing or detecting of parameters; Sensors therefor
    • F25B2700/21—Temperatures
    • F25B2700/2105—Oil temperatures

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Abstract

<P>PROBLEM TO BE SOLVED: To provide an oil quantity determining device, a refrigeration device and its control method for detecting whether the oil quantity in a compressor gets low or not without using an oil level sensor. <P>SOLUTION: A temperature in a case when a compressed refrigerant of one compressor is changed to a refrigerant of suction pressure of the compressor by isenthalpic change, is calculated on the basis of a discharge temperature, a discharge pressure and the suction pressure of the compressor (for example, compressor 20A), the calculated temperature is compared with an oil temperature of an oil tube 61, and whether the oil quantity in the compressor gets low or not is determined on the basis of a result of the comparison. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

本発明は、圧縮機内のオイル量を判定するオイル量判定装置、複数の高圧容器の圧縮機を備え、一の圧縮機の高圧部と他の圧縮機の低圧部とを、オイル管で接続した冷凍装置及びその制御方法に関する。   The present invention includes an oil amount determination device that determines the amount of oil in a compressor, and compressors of a plurality of high-pressure containers, and a high pressure portion of one compressor and a low pressure portion of another compressor are connected by an oil pipe. The present invention relates to a refrigeration apparatus and a control method thereof.

従来より、複数の高圧容器の圧縮機を備え、一の圧縮機の高圧部と他の圧縮機の低圧部とを、オイル管（均油管）で接続した冷凍装置が知られている。この種の冷凍装置は、冷媒が流れる同一系統内に複数台の圧縮機を備えるので、運転中にいずれかの圧縮機内のオイル（潤滑油）が不足する可能性がある。このため、この種の冷凍装置は、各圧縮機内のオイル量を検知する油面センサを備え、この油面センサによってオイル量の不足を検知している（例えば、特許文献１）。
特許第３２２９６４８号公報 2. Description of the Related Art Conventionally, a refrigeration apparatus including a plurality of high-pressure vessel compressors and connecting a high-pressure portion of one compressor and a low-pressure portion of another compressor with an oil pipe (an oil equalizing pipe) is known. Since this type of refrigeration apparatus includes a plurality of compressors in the same system through which refrigerant flows, there is a possibility that the oil (lubricating oil) in any of the compressors will be insufficient during operation. For this reason, this kind of freezing apparatus is provided with the oil level sensor which detects the oil quantity in each compressor, and is detecting the shortage of the oil quantity by this oil level sensor (for example, patent documents 1).
Japanese Patent No. 3229648

しかし、従来の構成では、圧縮機の数だけ油面センサが必要であり、しかも、油面センサには、一般にフロート式の油面センサが用いられるため、部品点数が多くなってしまう。   However, the conventional configuration requires as many oil level sensors as the number of compressors, and moreover, since a float type oil level sensor is generally used as the oil level sensor, the number of parts increases.

そこで、本発明の目的は、油面センサを用いることなく、圧縮機内のオイル量が不足しているか否かを検知することができるオイル量判定装置、冷凍装置及びその制御方法を提供することにある。   Therefore, an object of the present invention is to provide an oil amount determination device, a refrigeration device, and a control method thereof that can detect whether or not the amount of oil in the compressor is insufficient without using an oil level sensor. is there.

上述課題を解決するため、本発明は、オイル量判定装置において、一の圧縮機の高圧部と他の圧縮機の低圧部とを接続するオイル管のオイル温度を測定するオイル温度センサと、前記一の圧縮機の吐出温度、吐出圧力及び吸込圧力に基づいて、前記一の圧縮機の圧縮冷媒が等エンタルピ変化により前記一の圧縮機の吸込圧力の冷媒に変化した場合の温度を算出する温度算出手段と、この温度算出手段が算出した温度と前記オイル温度センサの測定温度とを比較し、この比較結果に基づいて、前記一の圧縮機内のオイル量が不足しているか否かを判定するオイル量判定手段とを備えたことを特徴とする。   In order to solve the above-described problems, the present invention provides an oil amount sensor that measures an oil temperature of an oil pipe that connects a high pressure part of one compressor and a low pressure part of another compressor, The temperature for calculating the temperature when the compressed refrigerant of the one compressor is changed to the refrigerant of the suction pressure of the one compressor due to the isenthalpy change based on the discharge temperature, discharge pressure and suction pressure of the one compressor The calculating means compares the temperature calculated by the temperature calculating means with the measured temperature of the oil temperature sensor, and determines whether or not the amount of oil in the one compressor is insufficient based on the comparison result. And an oil amount determining means.

また、本発明は、複数の高圧容器の圧縮機を備え、一の圧縮機の高圧部と他の圧縮機の低圧部とを、オイル管で接続した冷凍装置において、前記オイル管のオイル温度を測定するセンサと、前記一の圧縮機の吐出温度、吐出圧力及び吸込圧力に基づいて、前記一の圧縮機の圧縮冷媒が等エンタルピ変化により前記一の圧縮機の吸込圧力の冷媒に変化した場合の温度を算出する温度算出手段と、この温度算出手段が算出した温度と前記センサの測定温度とを比較し、この比較結果に基づいて、前記一の圧縮機内のオイル量が不足しているか否かを判定するオイル量判定手段とを備えたことを特徴とする。   The present invention also includes a compressor having a plurality of high-pressure containers, wherein the oil temperature of the oil pipe is set in a refrigeration apparatus in which a high-pressure part of one compressor and a low-pressure part of another compressor are connected by an oil pipe. Based on the sensor to be measured and the discharge temperature, discharge pressure, and suction pressure of the one compressor, when the compressed refrigerant of the one compressor changes to the refrigerant of the suction pressure of the one compressor due to an equal enthalpy change The temperature calculation means for calculating the temperature of the engine, the temperature calculated by the temperature calculation means and the measured temperature of the sensor are compared, and based on the comparison result, whether or not the amount of oil in the one compressor is insufficient And an oil amount judging means for judging whether or not.

また、本発明は、複数の高圧容器の圧縮機を備え、一の圧縮機の高圧部と他の圧縮機の低圧部とを、オイル管で接続した冷凍装置において、前記オイル管のオイル温度を測定するオイル温度センサと、前記一の圧縮機の吐出温度を測定する吐出温度センサと、前記一の圧縮機の吐出圧力及び吸込圧力、並びに前記センサの測定温度に基づいて、前記オイル管を流れる前記一の圧縮機の圧縮冷媒が等エンタルピ変化により前記一の圧縮機の吐出圧力の冷媒に変化した場合の温度を算出する温度算出手段と、この温度算出手段が算出した温度と前記吐出温度センサの測定温度とを比較し、この比較結果に基づいて、前記一の圧縮機内のオイル量が不足しているか否かを判定するオイル量判定手段とを備えたことを特徴とする。   The present invention also includes a compressor having a plurality of high-pressure containers, wherein the oil temperature of the oil pipe is set in a refrigeration apparatus in which a high-pressure part of one compressor and a low-pressure part of another compressor are connected by an oil pipe. An oil temperature sensor to be measured, a discharge temperature sensor for measuring a discharge temperature of the one compressor, a discharge pressure and a suction pressure of the one compressor, and a temperature measured by the sensor flow through the oil pipe A temperature calculating means for calculating a temperature when the compressed refrigerant of the one compressor is changed to a refrigerant having a discharge pressure of the one compressor due to a change in isoenthalpy; the temperature calculated by the temperature calculating means; and the discharge temperature sensor And an oil amount determination means for determining whether or not the amount of oil in the one compressor is insufficient based on the comparison result.

また、本発明は、上記発明において、前記オイル管は、前記一の圧縮機内のオイル量が予め定めたオイルレベル以下の場合に、その圧縮機内の圧縮冷媒が前記オイル管を介して他の圧縮機に流出するように、前記一の圧縮機の所定位置に接続され、前記オイル量判定手段は、前記一の圧縮機内のオイル量が前記オイルレベル以下か否かを判定することを特徴とする。また、本発明は、上記発明において、前記オイル管は絞りを備え、前記センサは、前記オイル管の絞りと前記他の圧縮機の低圧部との間の温度を測定することを特徴とする。   Further, the present invention provides the oil pipe according to the above invention, wherein when the amount of oil in the one compressor is equal to or lower than a predetermined oil level, the compressed refrigerant in the compressor passes through another oil pipe through the oil pipe. It is connected to a predetermined position of the one compressor so as to flow into the machine, and the oil amount determination means determines whether or not the oil amount in the one compressor is equal to or less than the oil level. . Further, the present invention is characterized in that, in the above-mentioned invention, the oil pipe includes a throttle, and the sensor measures a temperature between the throttle of the oil pipe and a low pressure part of the other compressor.

また、本発明は、複数の高圧容器の圧縮機を備え、一の圧縮機の高圧部と他の圧縮機の低圧部とを、オイル管で接続した冷凍装置の制御方法において、
前記一の圧縮機の吐出温度、吐出圧力及び吸込圧力に基づいて、前記一の圧縮機の圧縮冷媒が等エンタルピ変化により前記一の圧縮機の吸込圧力の冷媒に変化した場合の温度を算出する温度算出ステップと、前記算出した温度と、前記オイル管のオイル温度とを比較し、この比較結果に基づいて、前記一の圧縮機内のオイル量が不足しているか否かを判定するオイル量判定ステップとを備えたことを特徴とする。 Further, the present invention is a control method of a refrigeration apparatus comprising a plurality of high-pressure vessel compressors, wherein a high-pressure part of one compressor and a low-pressure part of another compressor are connected by an oil pipe,
Based on the discharge temperature, discharge pressure, and suction pressure of the one compressor, the temperature when the compressed refrigerant of the one compressor is changed to the refrigerant of the suction pressure of the one compressor due to an isenthalpy change is calculated. An oil amount determination that compares a temperature calculation step with the calculated temperature and the oil temperature of the oil pipe and determines whether or not the amount of oil in the one compressor is insufficient based on the comparison result And a step.

また、本発明は、複数の高圧容器の圧縮機を備え、一の圧縮機の高圧部と他の圧縮機の低圧部とを、オイル管で接続した冷凍装置の制御方法において、前記一の圧縮機の吐出圧力及び吸込圧力、並びに前記センサの測定温度に基づいて、前記オイル管を流れる前記一の圧縮機の圧縮冷媒が等エンタルピ変化により前記一の圧縮機の吐出圧力の冷媒に変化した場合の温度を算出する温度算出ステップと、前記算出した温度と前記一の圧縮機の吐出温度とを比較し、この比較結果に基づいて、前記一の圧縮機内のオイル量が不足しているか否かを判定するオイル量判定ステップとを備えたことを特徴とする。   Further, the present invention provides a method for controlling a refrigeration apparatus comprising a plurality of high-pressure vessel compressors, wherein a high-pressure part of one compressor and a low-pressure part of another compressor are connected by an oil pipe. When the compressed refrigerant of the one compressor flowing through the oil pipe is changed to the refrigerant of the discharged pressure of the one compressor due to an equal enthalpy change based on the discharge pressure and suction pressure of the compressor and the measured temperature of the sensor A temperature calculating step for calculating the temperature of the compressor, and comparing the calculated temperature with the discharge temperature of the one compressor, and based on the comparison result, whether or not the amount of oil in the one compressor is insufficient. An oil amount determining step for determining the oil amount.

本発明は、一の圧縮機の吐出温度、吐出圧力及び吸込圧力に基づいて、一の圧縮機の圧縮冷媒が等エンタルピ変化により一の圧縮機の吸込圧力の冷媒に変化した場合の温度を算出し、算出した温度とオイル管のオイル温度とを比較し、この比較結果に基づいて、一の圧縮機内のオイル量が不足しているか否かを判定するので、油面センサを用いることなく、圧縮機内のオイル量が不足しているか否かを検知することができる。   The present invention calculates the temperature when the compressed refrigerant of one compressor is changed to the refrigerant at the suction pressure of one compressor due to a change in isenthalpy based on the discharge temperature, discharge pressure and suction pressure of one compressor. Then, the calculated temperature and the oil temperature of the oil pipe are compared, and based on this comparison result, it is determined whether or not the amount of oil in one compressor is insufficient, so without using an oil level sensor, It is possible to detect whether or not the amount of oil in the compressor is insufficient.

以下、図面を参照して本発明の実施形態を詳述する。
図１は、本発明に係る冷凍装置の一例を示す空気調和装置１の回路図である。この空気調和装置１は、複数台（例えば２台）の室外ユニット２Ａ、２Ｂと、複数台（例えば２台）の室内ユニット３Ａ、３Ｂとを備えている。この空気調和装置１は、室外ユニット２Ａ、２Ｂと室内ユニット３Ａ、３Ｂとを接続する冷媒配管５が、低圧ガス管６と、高圧ガス管７と、液管８とから構成され、室内ユニット３Ａ、３Ｂを同時に冷房運転若しくは暖房運転可能とし、または、これらの冷房運転（ドライ運転を含む）と暖房運転とを混在して実施可能としている。 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a circuit diagram of an air conditioner 1 showing an example of a refrigeration apparatus according to the present invention. The air conditioner 1 includes a plurality of (for example, two) outdoor units 2A and 2B and a plurality of (for example, two) indoor units 3A and 3B. In the air conditioner 1, the refrigerant pipe 5 that connects the outdoor units 2A, 2B and the indoor units 3A, 3B includes a low-pressure gas pipe 6, a high-pressure gas pipe 7, and a liquid pipe 8, and the indoor unit 3A 3B can be simultaneously operated for cooling or heating, or the cooling operation (including dry operation) and the heating operation can be mixed.

室内ユニット３Ａは、室内熱交換器（利用側熱交換器）１０と膨張弁（減圧装置）１１とを備えて構成され、この室内熱交換器１０の一端は、膨張弁１１を介して液管８に配管接続される。また、室内熱交換器１０の他端には、分岐管１２が接続され、この分岐管１２は、高圧ガス分岐管１２Ａと低圧ガス分岐管１２Ｂとに分岐し、一方の高圧ガス分岐管１２Ａは第１開閉弁（例えば、電磁弁）１３を介して高圧ガス管７に接続され、他方の低圧ガス分岐管１２Ｂは第２開閉弁（例えば、電磁弁）１４を介して低圧ガス管６に接続される。また、室内ユニット３Ａには、室外熱交換器２１の出入口温度や室温を検出する温度センサ等が配置される他、これらセンサの検出結果を入力してこの室内ユニット３Ａの制御を行う室内制御装置（図示せず）を備えている。室内ユニット３Ｂは、室内ユニット３Ａと略同一の構成であるため、同一の部分に同一の符号を付して示し、重複する説明は省略する   The indoor unit 3 </ b> A includes an indoor heat exchanger (use side heat exchanger) 10 and an expansion valve (decompression device) 11, and one end of the indoor heat exchanger 10 is connected to the liquid pipe via the expansion valve 11. 8 is connected to the pipe. A branch pipe 12 is connected to the other end of the indoor heat exchanger 10, and this branch pipe 12 branches into a high-pressure gas branch pipe 12A and a low-pressure gas branch pipe 12B. The first open / close valve (for example, electromagnetic valve) 13 is connected to the high pressure gas pipe 7, and the other low pressure gas branch pipe 12 </ b> B is connected to the low pressure gas pipe 6 via the second open / close valve (for example, electromagnetic valve) 14. Is done. The indoor unit 3A is provided with a temperature sensor or the like for detecting the inlet / outlet temperature or room temperature of the outdoor heat exchanger 21, and an indoor controller for controlling the indoor unit 3A by inputting the detection results of these sensors. (Not shown). Since the indoor unit 3B has substantially the same configuration as the indoor unit 3A, the same portions are denoted by the same reference numerals, and redundant description is omitted.

図２は、室外ユニット２Ａの構成を示す回路図である。室外ユニット２Ａは、能力可変型の圧縮機（ＤＣインバータ圧縮機）２０Ａと、能力一定型の圧縮機（ＡＣ圧縮機）２０Ｂ１、２０Ｂ２と、室外熱交換器（熱源側熱交換器）２１と、膨張弁２２と、レシーバタンク２３等から概略構成されている。以下、各圧縮機２０Ａ、２０Ｂ１、２０Ｂ２を特に区別する必要がない場合は、圧縮機２０と表記する。   FIG. 2 is a circuit diagram showing a configuration of the outdoor unit 2A. The outdoor unit 2A includes a variable capacity compressor (DC inverter compressor) 20A, constant capacity compressors (AC compressors) 20B1, 20B2, an outdoor heat exchanger (heat source side heat exchanger) 21, An expansion valve 22 and a receiver tank 23 are roughly configured. Hereinafter, the compressors 20 </ b> A, 20 </ b> B <b> 1, 20 </ b> B <b> 2 are referred to as the compressors 20 when it is not necessary to distinguish between them.

各圧縮機２０Ａ、２０Ｂ１、２０Ｂ２は、圧縮動作時に内部が高圧となる高圧容器の圧縮機であり、図３に示すように、内部に溜まったオイル（潤滑油）がこれ以上下がるとオイル不足となるオイル基準面ＯＭに相当する高さに、オイル取出口６０が設けられる。圧縮機２０Ｂ１のオイル取出口６０は、オイル管６０を介して圧縮機２０Ａの吸込管３０Ａと接続され、圧縮機２０Ａのオイル取出口６０は、オイル管６０を介して圧縮機２０Ｂ２の吸込管３０Ｂ２と接続され、さらに、圧縮機２０Ｂ２のオイル取出口６０は、オイル管６０を介して圧縮機２０Ｂ１の吸込管３０Ｂ１と接続される。
すなわち、一の圧縮機２０の高圧部（高圧容器内）と他の圧縮機２０の低圧部（吸込管内）とがオイル管６１で連結された構成となっている。このため、一の圧縮機２０内のオイル量がオイル基準面ＯＭ以上となった場合、オイル基準面ＯＭ以上の余剰オイルが、オイル管６１を介して他の圧縮機２０内に供給され、各圧縮機２０Ａ、２０Ｂ１、２０Ｂ２内のオイル量が略均等に調整される。 Each of the compressors 20A, 20B1, and 20B2 is a high-pressure container compressor that has a high pressure inside during compression operation, and as shown in FIG. An oil outlet 60 is provided at a height corresponding to the oil reference plane OM. The oil outlet 60 of the compressor 20B1 is connected to the suction pipe 30A of the compressor 20A via the oil pipe 60, and the oil outlet 60 of the compressor 20A is connected to the suction pipe 30B2 of the compressor 20B2 via the oil pipe 60. Furthermore, the oil outlet 60 of the compressor 20B2 is connected to the suction pipe 30B1 of the compressor 20B1 via the oil pipe 60.
That is, the high pressure part (inside the high pressure vessel) of one compressor 20 and the low pressure part (inside the suction pipe) of another compressor 20 are connected by the oil pipe 61. For this reason, when the amount of oil in one compressor 20 becomes equal to or greater than the oil reference plane OM, surplus oil equal to or greater than the oil reference plane OM is supplied into the other compressors 20 via the oil pipe 61. The amount of oil in the compressors 20A, 20B1, and 20B2 is adjusted substantially evenly.

これに対し、例えば、一の圧縮機２０Ｂ１内のオイル量がオイル基準面ＯＭ以下であって、一の圧縮機２０Ｂ１の高圧部と他の圧縮機２０Ａの低圧部とに所定の圧力差が存在している場合、一の圧縮機２０Ｂ１内の高圧ガス冷媒がオイル管６１を介して他の圧縮機２０Ａ内に流れる。図３に示すように、オイル管６１には、キャピラリーチューブ（絞り）６２が設けられているため、高圧ガス冷媒は、等エンタルピ変化により減圧・膨張化し、低圧ガス冷媒として他の圧縮機２０Ａに供給される。また、オイル管６１におけるキャピラリーチューブ６２と他の圧縮機２０との間（オイル管６１のキャピラリーチューブ６２の下流側）には、オイル管６１のオイル温度を測定する温度センサ（例えば、サーミスタ）ＳＲが取り付けられている。   On the other hand, for example, the amount of oil in one compressor 20B1 is less than or equal to the oil reference plane OM, and there is a predetermined pressure difference between the high pressure part of one compressor 20B1 and the low pressure part of the other compressor 20A. In this case, the high-pressure gas refrigerant in one compressor 20B1 flows into the other compressor 20A via the oil pipe 61. As shown in FIG. 3, since the oil tube 61 is provided with a capillary tube (throttle) 62, the high-pressure gas refrigerant is depressurized and expanded by a change in isenthalpy, and is supplied to the other compressor 20A as a low-pressure gas refrigerant. Supplied. A temperature sensor (for example, a thermistor) SR for measuring the oil temperature of the oil pipe 61 is provided between the capillary tube 62 in the oil pipe 61 and the other compressor 20 (on the downstream side of the capillary tube 62 of the oil pipe 61). Is attached.

図２に示すように、各圧縮機２０Ａ、２０Ｂ１、２０Ｂ２は、並列接続され、各圧縮機２０Ａ、２０Ｂ１、２０Ｂ２の吸込口に共通接続された吸込管３０が、アキュムレータ２４を介して低圧ガス管６に接続される。また、各圧縮機２０Ａ、２０Ｂ１、２０Ｂ２の吐出口に接続された吐出管３１は、オイルセパレータ２５を介して２つに分岐し、一方の冷媒吐出分岐管３１Ａが高圧ガス管７に接続され、他方の冷媒吐出分岐管３１Ｂが室外熱交換器２１に接続される。   As shown in FIG. 2, the compressors 20 </ b> A, 20 </ b> B <b> 1, 20 </ b> B <b> 2 are connected in parallel, and a suction pipe 30 commonly connected to the suction ports of the compressors 20 </ b> A, 20 </ b> B <b> 1, 20 </ b> B <b> 2 is connected via an accumulator 24. 6 is connected. The discharge pipe 31 connected to the discharge port of each compressor 20A, 20B1, 20B2 branches into two via the oil separator 25, and one refrigerant discharge branch pipe 31A is connected to the high-pressure gas pipe 7, The other refrigerant discharge branch pipe 31 </ b> B is connected to the outdoor heat exchanger 21.

ここで、上記冷媒吐出分岐管３１Ｂには、切換弁４０が設けられ、この切換弁４０を開けると圧縮機２０の吐出冷媒が室外熱交換器２１に供給される。さらに、この冷媒吐出分岐管３１Ｂには、上記切換弁４０と室外熱交換器２１との間に四方弁４１が設けられ、この四方弁４１は、室外熱交換器２１から見て、室外熱交換器２１の一端を、上記切換弁４０につながる管路（冷媒吐出分岐管３１Ｂ＋冷媒吐出分岐管３１Ａ）、又は圧縮機２０の吸込管３０につながる管路（暖房経路用配管３２）のいずれか一方に選択的に切り換える切換弁として機能する。   Here, the refrigerant discharge branch pipe 31 </ b> B is provided with a switching valve 40, and when the switching valve 40 is opened, the refrigerant discharged from the compressor 20 is supplied to the outdoor heat exchanger 21. Further, the refrigerant discharge branch pipe 31B is provided with a four-way valve 41 between the switching valve 40 and the outdoor heat exchanger 21, and the four-way valve 41 is viewed from the outdoor heat exchanger 21 as an outdoor heat exchanger. One end of the vessel 21 is either one of a pipe line connected to the switching valve 40 (refrigerant discharge branch pipe 31B + refrigerant discharge branch pipe 31A) or a pipe line connected to the suction pipe 30 of the compressor 20 (heating pipe 32). It functions as a switching valve that selectively switches to.

室外熱交換器２１の他端は、室外熱交換器２１に供給する冷媒流量を調整するための膨張弁２６、レシーバタンク２３及び補助冷却回路２８を介して液管８と配管接続される。レシーバタンク２３は、室外ユニット２Ａと室内ユニット３Ａ、３Ｂとの間の液状冷媒を蓄えて各ユニット間の冷媒の需給の調整を図るものである。
また、補助冷却回路２８は、レシーバタンク２３と液管８とを接続する冷媒配管３３を流れる液冷媒を補助冷却するものであり、より具体的には、レシーバタンク２３と液管８との間の液冷媒が通る配管３３の一部と、この配管３３から分岐して膨張弁２９を通過した冷媒が通る分岐管３４の一部とを２重管で構成した、いわゆる２重管式熱交換器が適用される。この分岐管３４は、補助冷却回路２８に接続された冷媒配管３５を介して圧縮機２０の吸込管３０とつながり、この分岐管３４、３５を通過した冷媒は圧縮機２０の吸込口に戻される。 The other end of the outdoor heat exchanger 21 is connected to the liquid pipe 8 through an expansion valve 26 for adjusting the flow rate of the refrigerant supplied to the outdoor heat exchanger 21, a receiver tank 23, and an auxiliary cooling circuit 28. The receiver tank 23 stores liquid refrigerant between the outdoor unit 2A and the indoor units 3A and 3B, and adjusts supply and demand of the refrigerant between the units.
The auxiliary cooling circuit 28 is for auxiliary cooling of the liquid refrigerant flowing through the refrigerant pipe 33 connecting the receiver tank 23 and the liquid pipe 8, and more specifically, between the receiver tank 23 and the liquid pipe 8. So-called double-pipe heat exchange in which a part of the pipe 33 through which the liquid refrigerant passes and a part of the branch pipe 34 through which the refrigerant branches from the pipe 33 and passes through the expansion valve 29 are constituted by double pipes. The vessel is applied. The branch pipe 34 is connected to the suction pipe 30 of the compressor 20 via a refrigerant pipe 35 connected to the auxiliary cooling circuit 28, and the refrigerant that has passed through the branch pipes 34 and 35 is returned to the suction port of the compressor 20. .

また、オイルセパレータ２５には、図２に示すように、オイルセパレータ２５に溜められたオイル量が所定量以上の場合に、余剰のオイル（潤滑油）を圧縮機２０の吸込管３０に戻す冷媒戻し管４５と、当該オイルセパレータ２５と他の室外ユニット２Ｂのオイルセパレータ２５とを接続するためのオイルバランス管４６とが接続される。このオイルバランス管４６は、開閉弁４６Ａを備え、図１に示すように、オイル管４７を介して他の室外ユニット２Ｂのオイルセパレータ２５と接続されると共に、このオイルバランス管４６から分岐する分岐管４５Ａを介して冷媒戻し管４５に接続される。
この分岐管４５Ａには、開閉弁４５Ｂが設けられる。このため、開閉弁４６Ａが開き、開閉弁４５Ｂが閉じると、オイルセパレータ２５に貯留されたオイルが他の室外ユニット２Ｂに供給され、開閉弁４６Ａが閉じ、開閉弁４５Ｂが開くと、他の室外ユニット２Ｂから供給されたオイルが分岐管４５Ａを介して冷媒戻し管４５に供給され、これによって、室外ユニット２Ａ、２Ｂ間をオイルが行き来可能に構成されている。 Further, as shown in FIG. 2, the oil separator 25 is a refrigerant that returns excess oil (lubricating oil) to the suction pipe 30 of the compressor 20 when the amount of oil stored in the oil separator 25 is greater than or equal to a predetermined amount. The return pipe 45 is connected to an oil balance pipe 46 for connecting the oil separator 25 and the oil separator 25 of the other outdoor unit 2B. The oil balance pipe 46 includes an on-off valve 46A, and is connected to the oil separator 25 of another outdoor unit 2B via an oil pipe 47 and branched from the oil balance pipe 46 as shown in FIG. The refrigerant return pipe 45 is connected via the pipe 45A.
The branch pipe 45A is provided with an on-off valve 45B. Therefore, when the on-off valve 46A is opened and the on-off valve 45B is closed, the oil stored in the oil separator 25 is supplied to the other outdoor unit 2B, and when the on-off valve 46A is closed and the on-off valve 45B is opened, The oil supplied from the unit 2B is supplied to the refrigerant return pipe 45 via the branch pipe 45A, so that the oil can travel between the outdoor units 2A and 2B.

また、室外ユニット２Ａは、圧縮機２０の吸込圧力を検出する圧力センサＳＡ、圧縮機２０の吐出圧力を検出する圧力センサＳＢ、圧縮機２０の吐出温度を測定する温度センサＳＴ、室外熱交換器２１の出入口温度を検出する温度センサＳＯ１、ＳＯ２等の各種センサ、複数の逆止弁、各種センサの検出結果を入力して室外ユニット２Ａ全体を制御する室外制御装置（温度算出手段、オイル量判定手段）１００等を備える。室外ユニット２Ｂについては、室外ユニット２Ａと略同一の構成であるため、同一の部分には同一の符号を付して示し、重複する説明は省略する。さらに、この空気調和装置１は、図示を省略したリモートコントローラを備え、室外ユニット２Ａ、２Ｂのいずれかの室外制御装置１００が、リモートコントローラを介して入力したユーザ指示等に応じて、他の室外制御装置１００や室内制御装置と通信し、この空気調和装置１全体の運転制御を行う。   The outdoor unit 2A includes a pressure sensor SA that detects the suction pressure of the compressor 20, a pressure sensor SB that detects the discharge pressure of the compressor 20, a temperature sensor ST that measures the discharge temperature of the compressor 20, and an outdoor heat exchanger. 21. Various sensors such as temperature sensors SO1 and SO2 that detect the inlet / outlet temperature of 21, a plurality of check valves, an outdoor control device that controls the entire outdoor unit 2A by inputting the detection results of the various sensors (temperature calculation means, oil amount determination) Means) 100 and the like. Since the outdoor unit 2B has substantially the same configuration as the outdoor unit 2A, the same portions are denoted by the same reference numerals, and redundant description is omitted. Furthermore, the air conditioner 1 includes a remote controller (not shown), and the outdoor control device 100 of any one of the outdoor units 2A and 2B receives another outdoor unit according to a user instruction or the like input via the remote controller. It communicates with the control device 100 and the indoor control device, and performs operation control of the entire air conditioner 1.

具体的には、全ての室内ユニット３Ａ、３Ｂを同時に冷房運転する場合、各室外ユニット２Ａ、２Ｂでは、切換弁４０が開くと共に四方弁４１が切換制御され、また、各室内ユニット３Ａ、３Ｂでは第１開閉弁１３が閉じ、第２開閉弁１４が開く。この場合、図１に実線矢印で示すように、圧縮機２０の吐出冷媒が、オイルセパレータ２５を介して室外熱交換器２１に供給され、ここで放熱・凝縮して液冷媒となり、レシーバタンク２３及び補助冷却回路２８を経て液管８に供給される。
そして、室内ユニット３Ａ、３Ｂにおいては、液管８を介して液冷媒が膨張弁１１を介して室内熱交換器１０に供給され、ここで吸熱・蒸発し、低温低圧のガス冷媒となり、第２開閉弁１４を介して低圧ガス管６に供給される。この低圧ガス管６に供給されたガス冷媒は、室外ユニット２Ａ、２Ｂの吸込管３０を介して圧縮機２０で再び圧縮される。これによって、全ての室内ユニット３Ａ、３Ｂで同時に冷房運転が可能になる。 Specifically, when all the indoor units 3A and 3B are cooled at the same time, in each of the outdoor units 2A and 2B, the switching valve 40 is opened and the four-way valve 41 is switched, and in each of the indoor units 3A and 3B, The first on-off valve 13 is closed and the second on-off valve 14 is opened. In this case, as indicated by solid line arrows in FIG. 1, the refrigerant discharged from the compressor 20 is supplied to the outdoor heat exchanger 21 via the oil separator 25, where heat is dissipated and condensed to form liquid refrigerant, and the receiver tank 23. And it is supplied to the liquid pipe 8 through the auxiliary cooling circuit 28.
In the indoor units 3A and 3B, the liquid refrigerant is supplied to the indoor heat exchanger 10 via the liquid pipe 8 via the expansion valve 11, where it absorbs and evaporates to become a low-temperature and low-pressure gas refrigerant. The gas is supplied to the low-pressure gas pipe 6 through the on-off valve 14. The gas refrigerant supplied to the low-pressure gas pipe 6 is compressed again by the compressor 20 through the suction pipes 30 of the outdoor units 2A and 2B. As a result, all the indoor units 3A and 3B can simultaneously perform the cooling operation.

一方、全ての室内ユニット３Ａ、３Ｂを同時に暖房運転する場合、各室外ユニット２Ａ、２Ｂでは、切換弁４０が閉じると共に四方弁４１が切換制御され、各室内ユニット３Ａ、３Ｂでは第１開閉弁１３が開き、第２開閉弁１４が閉じる。この場合、図１に波線矢印で示すように、圧縮機２０が吐出した高温高圧のガス冷媒が、オイルセパレータ２５を介して高圧ガス管７に供給される。
そして、室内ユニット３Ａ、３Ｂにおいては、高圧ガス管７を介してガス冷媒が室内熱交換器１０に供給され、ここで、放熱・凝縮して液冷媒となった後、膨張弁１１を介して液管８に供給される。この液管８に供給された液冷媒は、室外ユニット２Ａ、２Ｂの冷媒配管３３及びレシーバタンク２３を介して室外熱交換器２１に供給され、ここで、吸熱・蒸発し、ここで低温低圧のガス冷媒となり、吸込管３０を介して圧縮機２０で再び圧縮される。これによって、全ての室内ユニット３Ａ、３Ｂで同時に暖房運転が可能になる。 On the other hand, when all the indoor units 3A and 3B are simultaneously operated for heating, the switching valve 40 is closed and the four-way valve 41 is switched in each of the outdoor units 2A and 2B, and the first on-off valve 13 is controlled in each of the indoor units 3A and 3B. Opens and the second on-off valve 14 closes. In this case, the high-temperature and high-pressure gas refrigerant discharged from the compressor 20 is supplied to the high-pressure gas pipe 7 through the oil separator 25 as indicated by a wavy arrow in FIG.
In the indoor units 3A and 3B, the gas refrigerant is supplied to the indoor heat exchanger 10 via the high-pressure gas pipe 7, where after the heat is radiated and condensed to become a liquid refrigerant, the refrigerant is supplied via the expansion valve 11. It is supplied to the liquid pipe 8. The liquid refrigerant supplied to the liquid pipe 8 is supplied to the outdoor heat exchanger 21 through the refrigerant pipes 33 and the receiver tank 23 of the outdoor units 2A and 2B, where it absorbs heat and evaporates, where It becomes a gas refrigerant and is compressed again by the compressor 20 through the suction pipe 30. Thereby, the heating operation can be simultaneously performed in all the indoor units 3A and 3B.

また、暖房運転と冷房運転の混在運転を行う場合、例えば、室内ユニット３Ａを暖房運転し、室内ユニット３Ｂを冷房運転する場合、室外ユニット２Ａ、２Ｂが上記同時暖房運転の場合と同様に制御される一方、室内ユニット３Ａにおいては、第１開閉弁１３が閉じ、第２開閉弁１４が開き、室内ユニット３Ｂにおいては、第１開閉弁１３が開き、第２開閉弁１５が閉じる。この場合、各室外ユニット２Ａ、２Ｂから高温高圧のガス冷媒が高圧ガス管７に供給され、室内ユニット３Ａにおいては、高圧ガス管７を介してガス冷媒が室内熱交換器１０に供給され、ここで放熱・凝縮して液冷媒となった後、膨張弁１１を介して液管８に供給される。この液管８に供給された液冷媒の一部は室外ユニット２Ａ、２Ｂへ戻り、室外熱交換器２１で吸熱・蒸発し、低温低圧のガス冷媒となる。   Further, when performing a mixed operation of heating operation and cooling operation, for example, when the indoor unit 3A is operated for heating and the indoor unit 3B is operated for cooling, the outdoor units 2A and 2B are controlled in the same manner as in the above-mentioned simultaneous heating operation. On the other hand, in the indoor unit 3A, the first on-off valve 13 is closed and the second on-off valve 14 is opened, and in the indoor unit 3B, the first on-off valve 13 is opened and the second on-off valve 15 is closed. In this case, high-temperature and high-pressure gas refrigerant is supplied from the outdoor units 2A and 2B to the high-pressure gas pipe 7, and in the indoor unit 3A, gas refrigerant is supplied to the indoor heat exchanger 10 via the high-pressure gas pipe 7. After being radiated / condensed to form a liquid refrigerant, it is supplied to the liquid pipe 8 via the expansion valve 11. A part of the liquid refrigerant supplied to the liquid pipe 8 returns to the outdoor units 2A and 2B, absorbs heat and evaporates in the outdoor heat exchanger 21, and becomes a low-temperature and low-pressure gas refrigerant.

一方、液管８に供給された液冷媒の残りは、室内ユニット３Ｂの室内熱交換器１０に供給され、ここで吸熱・蒸発し、低温低圧のガス冷媒となった後、第２開閉弁１４を介して低圧ガス管６に供給される。そして、この低圧ガス管６に供給された冷媒は、室外熱交換器２１を経た上記ガス冷媒と共に、吸込管３０を介して圧縮機２０で再び圧縮される。これによって、室内ユニット３Ａ、３Ｂ毎に暖房運転と冷房運転とが可能になる。   On the other hand, the remainder of the liquid refrigerant supplied to the liquid pipe 8 is supplied to the indoor heat exchanger 10 of the indoor unit 3B, where it absorbs heat and evaporates to become a low-temperature and low-pressure gas refrigerant, and then the second on-off valve 14. Is supplied to the low-pressure gas pipe 6. The refrigerant supplied to the low-pressure gas pipe 6 is compressed again by the compressor 20 through the suction pipe 30 together with the gas refrigerant passed through the outdoor heat exchanger 21. Thereby, heating operation and cooling operation can be performed for each of the indoor units 3A and 3B.

ところで、上記冷房、暖房運転中において、圧縮機２０Ａ、２０Ｂ１、２０Ｂ２内のオイル（潤滑油）は冷媒と共に同一系統内を流れる。この同一系統には、複数の圧縮機２０Ａ、２０Ｂ１、２０Ｂ２が設けられるので、運転中にいずれかの圧縮機２０Ａ、２０Ｂ１、２０Ｂ２にオイルが偏って蓄積されると、いずれかの圧縮機２０Ａ、２０Ｂ１、２０Ｂ２にオイル不足が生じるおそれがある。   By the way, during the cooling and heating operations, the oil (lubricating oil) in the compressors 20A, 20B1, and 20B2 flows in the same system together with the refrigerant. Since the same system is provided with a plurality of compressors 20A, 20B1, and 20B2, if oil is biased and accumulated in any of the compressors 20A, 20B1, and 20B2 during operation, any one of the compressors 20A, Oil shortage may occur in 20B1 and 20B2.

本実施形態では、圧縮機２０Ａ、２０Ｂ１、２０Ｂ２にオイル不足が生じているか否かを検出するためのオイル量検出処理が実行される。この処理は、室外制御装置１００により実行される。
図４は、オイル量検出処理を示すフローチャートである。以下、圧縮機２０Ａに対して行う場合を例に説明する。まず、室外制御装置１００は、温度センサＳＴ及び圧力センサＳＡ、ＳＢにより、圧縮機２０Ａの吐出温度ＴＨ、吐出圧力ＨＰ及び吸込圧力ＬＰの測定値を取得し、図５に示すように、各値ＴＨ、ＨＰ、ＬＰから圧縮機２０Ａのガス冷媒が等エンタルピ変化により吸込圧力ＬＰの冷媒に変化した場合の温度ＴＬを求めるべく、以下に示す（１）式を用いて、温度ＴＬを算出する（ステップＳ１）。 In the present embodiment, an oil amount detection process for detecting whether or not oil shortage has occurred in the compressors 20A, 20B1, and 20B2 is executed. This process is executed by the outdoor control device 100.
FIG. 4 is a flowchart showing the oil amount detection process. Hereinafter, the case where it performs with respect to the compressor 20A is demonstrated to an example. First, the outdoor control device 100 acquires the measured values of the discharge temperature TH, the discharge pressure HP, and the suction pressure LP of the compressor 20A using the temperature sensor ST and the pressure sensors SA and SB, and each value is shown in FIG. In order to obtain the temperature TL when the gas refrigerant of the compressor 20A changes from TH, HP, LP to the refrigerant having the suction pressure LP due to the isenthalpy change, the temperature TL is calculated using the following equation (1) ( Step S1).

ＴＬ＝ｆ（ＨＰ，ＬＰ，ＴＨ）・・・（１）   TL = f (HP, LP, TH) (1)

次に、室外制御装置１００は、温度センサＳＲにより、圧縮機２０Ａのオイル管６１のオイル温度ＴＲを取得し、このオイル温度ＴＲが上記温度ＴＬより低いか否かを判定する（ステップＳ２）。
ここで、オイル管６１をガス冷媒が流れている場合は、ガス冷媒はキャピラリーチューブ６２で等エンタルピ変化にて圧縮機２０Ａの低圧（吸込圧力ＬＰ）に減圧し、さらに、ガス冷媒のため熱容量が小さく冷やされやすいことから、オイル管６１通過中に周囲空気により冷やされ、等エンタルピ変化だけを考慮して算出した温度ＴＬよりも低くなる。
一方、オイル管６１をオイルが流れている場合、液体であるオイルはキャピラリーチューブ６２を通過しても膨張せず、しかもオイルは熱容量がガス冷媒よりも極めて大きいため、仮にオイル管６１の周囲空気が低くオイル管６１通過中に冷やされとしても、そのオイル温度は、上記算出した温度ＴＬよりも高い温度となる。 Next, the outdoor control device 100 acquires the oil temperature TR of the oil pipe 61 of the compressor 20A by the temperature sensor SR, and determines whether or not the oil temperature TR is lower than the temperature TL (step S2).
Here, when the gas refrigerant is flowing through the oil pipe 61, the gas refrigerant is depressurized to the low pressure (suction pressure LP) of the compressor 20A by a change in isenthalpy in the capillary tube 62, and further, the heat capacity is increased because of the gas refrigerant. Since it is small and easy to cool, it is cooled by ambient air while passing through the oil pipe 61, and becomes lower than the temperature TL calculated in consideration of only the change in isenthalpy.
On the other hand, when oil flows through the oil pipe 61, the liquid oil does not expand even when it passes through the capillary tube 62, and the oil has a much larger heat capacity than the gas refrigerant. Even when the oil pipe 61 is cooled while passing through the oil pipe 61, the oil temperature becomes higher than the calculated temperature TL.

このため、室外制御装置１００は、測定したオイル温度ＴＲが上記温度ＴＬより低い場合（ステップＳ２：YES）、オイル管６１をガス冷媒が流れていると判断できるため、圧縮機２０Ａ内のオイルがオイル基準面ＯＭ以下であり、オイル量が不足していると判定する（ステップＳ３）。一方、室外制御装置１００は、測定したオイル温度ＴＲが上記温度ＴＬより高い場合（ステップＳ２：NO）、オイル管６１をオイルが流れていると判断できるため、圧縮機２０Ａ内のオイルがオイル基準面ＯＭ以上であり、オイル有りと判定する（ステップＳ４）。以上が、オイル量検出処理である。このオイル量検出処理は、所定周期で繰り返し実行され、オイルの有無が継続的に判定される。
なお、本実施形態では、オイル量検出処理を圧縮機２０Ａに対して行う場合を例に説明したが、全ての圧縮機２０Ａ、２０Ｂ１、２０Ｂ２に対して行なってもよく、或いは、室外ユニット２Ａ、３Ａ毎に各一台の圧縮機２０だけに対して行うようにしてもよい。 For this reason, the outdoor control device 100 can determine that the gas refrigerant is flowing through the oil pipe 61 when the measured oil temperature TR is lower than the temperature TL (step S2: YES). It is determined that it is below the oil reference plane OM and the amount of oil is insufficient (step S3). On the other hand, when the measured oil temperature TR is higher than the temperature TL (step S2: NO), the outdoor control device 100 can determine that the oil is flowing through the oil pipe 61, so that the oil in the compressor 20A is the oil reference. It is determined that the surface is equal to or greater than OM and there is oil (step S4). The above is the oil amount detection process. This oil amount detection process is repeatedly executed at a predetermined cycle, and the presence or absence of oil is continuously determined.
In the present embodiment, the case where the oil amount detection process is performed on the compressor 20A has been described as an example, but may be performed on all the compressors 20A, 20B1, and 20B2, or the outdoor unit 2A, You may make it carry out only with respect to each one compressor 20 every 3A.

上記オイル量検出処理の結果、圧縮機２０内のオイル量が不足していると判定した場合、室外制御装置１００は、圧縮機２０のオイル不足を解消すべく、オイル不足の圧縮機２０が能力一定型の圧縮機２０Ｂ１、２０Ｂ２の場合は、運転を停止し、若しくは、能力可変型の圧縮機２０Ａの場合は運転周波数を運転可能な最低周波数まで下げる、又は、オイルバランス管４６及びオイル管４７を経由して、オイルの不足する室外ユニット側に、他の室外ユニット内のオイルを回収させる等のオイル不足解消処理を実行する。   When it is determined that the amount of oil in the compressor 20 is insufficient as a result of the oil amount detection process, the outdoor control device 100 determines that the compressor 20 with insufficient oil is capable of solving the oil shortage of the compressor 20. In the case of the constant type compressors 20B1 and 20B2, the operation is stopped, or in the case of the variable capacity type compressor 20A, the operation frequency is lowered to the lowest operable frequency, or the oil balance pipe 46 and the oil pipe 47 Then, an oil shortage elimination process such as collecting the oil in the other outdoor units is performed on the outdoor unit side where the oil is short.

このように、本実施形態では、圧縮機２０の圧縮冷媒が等エンタルピ変化によりその圧縮機２０の吸込圧力の冷媒に変化した場合の温度ＴＲを算出し、この算出温度ＴＲと、オイル管６１のオイル温度ＴＲの測定値との比較により圧縮機２０のオイル不足を検知するため、フロート式の油面センサを用いて圧縮機のオイル不足を検知する従来のものに比して、部品点数を少なくすることができ、空気調和装置１のコスト低減に有利となる。   As described above, in this embodiment, the temperature TR when the compressed refrigerant of the compressor 20 is changed to the refrigerant having the suction pressure of the compressor 20 due to the isenthalpy change is calculated, and the calculated temperature TR and the oil pipe 61 Compared with the measured value of the oil temperature TR, the oil shortage of the compressor 20 is detected, so the number of parts is reduced compared to the conventional one that detects the oil shortage of the compressor using a float type oil level sensor. This is advantageous in reducing the cost of the air conditioner 1.

以上、本発明の一実施形態について説明したが、本発明はこれに限定されるものではない。例えば、上記実施形態では、圧縮機２０の圧縮冷媒が等エンタルピ変化によりその圧縮機２０の吸込圧力の冷媒に変化した場合の算出温度ＴＲと、オイル温度ＴＲとの比較によりオイル不足か否かを判定する場合について例示したが、本発明はこれに限らない。
具体的には、図６に他のオイル量検出処理を示すように、室外制御装置１００は、圧力センサＳＡ、ＳＢ及び温度センサＳＲにより、圧縮機２０の吐出圧力ＨＰ、吸込圧力ＬＰ及びオイル管６１のオイル温度ＴＲを取得し、図７に示すように、各値ＨＰ、ＬＰ、ＴＲから、オイル管６１を流れる圧縮機２０のガス冷媒が等エンタルピ変化により吐出圧力ＨＰの冷媒に変化した場合の温度ＴＨＫを求めるべく、以下に示す（２）式を用いて、温度ＴＨＫを算出する（ステップＳ１Ａ）。 Although one embodiment of the present invention has been described above, the present invention is not limited to this. For example, in the above-described embodiment, whether the compressed refrigerant of the compressor 20 is changed to the refrigerant having the suction pressure of the compressor 20 due to the isenthalpy change and whether the oil is short by comparing the oil temperature TR. Although the case of determination is illustrated, the present invention is not limited to this.
Specifically, as shown in another oil amount detection process in FIG. 6, the outdoor control device 100 uses the pressure sensors SA and SB and the temperature sensor SR to discharge the discharge pressure HP, the suction pressure LP, and the oil pipe of the compressor 20. When the oil temperature TR of 61 is acquired and the gas refrigerant of the compressor 20 flowing through the oil pipe 61 is changed from the values HP, LP, TR to the refrigerant of the discharge pressure HP due to the isenthalpy change, as shown in FIG. In order to obtain the temperature THK, the temperature THK is calculated using the following equation (2) (step S1A).

ＴＨＫ＝ｇ（ＨＰ，ＬＰ，ＴＲ）・・・（２）   THK = g (HP, LP, TR) (2)

次に、室外制御装置１００は、温度センサＳＴにより、圧縮機２０の吐出温度ＴＨを取得し、この吐出温度ＴＨが上記温度ＴＨＫより高いか否かを判定する（ステップＳ２Ａ）。
図７に示すように、オイル管６１をガス冷媒が流れている場合は、吐出温度ＴＨが上記温度ＴＨＫより高くなるため、かかる場合（ステップＳ２Ａ：YES）、室外制御装置１００は、圧縮機２０内のオイルがオイル基準面ＯＭ以下であり、オイル量が不足していると判定する（ステップＳ３Ａ）。 Next, the outdoor control device 100 acquires the discharge temperature TH of the compressor 20 by the temperature sensor ST, and determines whether or not the discharge temperature TH is higher than the temperature THK (step S2A).
As shown in FIG. 7, when the gas refrigerant is flowing through the oil pipe 61, the discharge temperature TH is higher than the temperature THK. In this case (step S2A: YES), the outdoor control device 100 is connected to the compressor 20 It is determined that the oil inside is below the oil reference plane OM and the amount of oil is insufficient (step S3A).

一方、吐出温度ＴＨが上記温度ＴＨＫより低い場合（ステップＳ２Ａ：NO）、室外制御装置１００は、圧縮機２０内のオイルがオイル基準面ＯＭ以上であり、オイル有りと判定する（ステップＳ４Ａ）。
このように、オイル管６１を流れる圧縮機２０のガス冷媒が等エンタルピ変化により吐出圧力ＨＰの冷媒に変化した場合の温度ＴＨＫを算出し、この算出温度ＴＨＫと、圧縮機２０の吐出温度ＴＨの測定値との比較によっても、圧縮機２０のオイル不足を検知することが可能である。 On the other hand, when the discharge temperature TH is lower than the temperature THK (step S2A: NO), the outdoor control device 100 determines that the oil in the compressor 20 is equal to or higher than the oil reference plane OM and there is oil (step S4A).
Thus, the temperature THK when the gas refrigerant of the compressor 20 flowing through the oil pipe 61 is changed to the refrigerant of the discharge pressure HP due to the isenthalpy change is calculated, and the calculated temperature THK and the discharge temperature TH of the compressor 20 are calculated. It is possible to detect an oil shortage of the compressor 20 also by comparison with the measured value.

また、上記実施形態で示した配管構成はこれに限定されるものではなく、本発明の趣旨を逸脱しない範囲で適宜変更が可能である。例えば、上記各実施形態では、圧縮機２０の圧縮冷媒がオイル管６１で等エンタルピ変化した後の温度ＴＲ、或いは、オイル管６１で等エンタルピ変化する前の温度ＴＨＫを算出する場合について述べたが、要は、測定したオイル温度ＴＲ又は吐出温度ＴＨＫとの比較により、オイル管６１をガス冷媒又はオイルが流れたか否かを特定可能な温度を算出すればよく、その範囲で上記算出式（１）（２）は変更が可能である。また、上記実施形態では、空気調和装置に本発明を適用する場合を例示したが、冷媒回路を備える冷凍装置や圧縮機のオイル量を測定するオイル量測定装置に広く適用が可能である。   Moreover, the piping configuration shown in the above embodiment is not limited to this, and can be appropriately changed without departing from the gist of the present invention. For example, in each of the embodiments described above, the case where the temperature TR after the compressed refrigerant of the compressor 20 undergoes an isoenthalpy change in the oil pipe 61 or the temperature THK before the isoenthalpy change in the oil pipe 61 is calculated has been described. In short, it is only necessary to calculate a temperature capable of specifying whether or not the gas refrigerant or oil has flowed through the oil pipe 61 by comparing with the measured oil temperature TR or the discharge temperature THK, and the above calculation formula (1 ) (2) can be changed. Moreover, although the case where this invention is applied to an air conditioning apparatus was illustrated in the said embodiment, it can apply widely to the oil quantity measuring apparatus which measures the oil quantity of a refrigerating device provided with a refrigerant circuit, and a compressor.

本発明に係る空気調和装置の一実施の形態を示す回路図である。It is a circuit diagram showing one embodiment of an air harmony device concerning the present invention. 室外ユニットの構成を示す回路図である。It is a circuit diagram which shows the structure of an outdoor unit. 圧縮機をその周辺構成と共に示す図である。It is a figure which shows a compressor with the periphery structure. オイル量検出処理を示すフローチャートである。It is a flowchart which shows an oil amount detection process. オイル量検出処理の説明に供するＰ−Ｈ線図である。It is a PH diagram with which it uses for description of an oil amount detection process. 変形例に係るオイル量検出処理を示すフローチャートである。It is a flowchart which shows the oil quantity detection process which concerns on a modification. 変形例に係るオイル量検出処理の説明に供するＰ−Ｈ線図である。It is a PH diagram with which it uses for description of the oil quantity detection process which concerns on a modification.

符号の説明Explanation of symbols

１ 空気調和装置（冷凍装置）
２Ａ、２Ｂ 室外ユニット
３Ａ、３Ｂ 室内ユニット
５ 冷媒配管
６ 高圧ガス管
７ 低圧ガス管
８ 液管
１０ 室内熱交換器（利用側熱交換器）
１１、２６ 膨張弁（減圧装置）
２０、２０Ａ、２０Ｂ、２０Ｃ 圧縮機
２１ 室外熱交換器（熱源側熱交換器）
２３ レシーバタンク
２４ アキュムレータ
２５ オイルセパレータ
２８ 補助冷却回路
３０、３０Ａ、３０Ｂ１、３０Ｂ２ 吸込管
６０ オイル取出口
６１ オイル管
６２ キャピラリーチューブ（絞り）
ＳＴ、ＳＲ 温度センサ
ＳＡ、ＳＢ 圧力センサ
１００ 室外制御装置（温度算出手段、オイル量判定手段） 1 Air conditioning equipment (refrigeration equipment)
2A, 2B Outdoor unit 3A, 3B Indoor unit 5 Refrigerant pipe 6 High pressure gas pipe 7 Low pressure gas pipe 8 Liquid pipe 10 Indoor heat exchanger (use side heat exchanger)
11, 26 Expansion valve (pressure reduction device)
20, 20A, 20B, 20C Compressor 21 Outdoor heat exchanger (heat source side heat exchanger)
23 receiver tank 24 accumulator 25 oil separator 28 auxiliary cooling circuit 30, 30A, 30B1, 30B2 suction pipe 60 oil outlet 61 oil pipe 62 capillary tube (throttle)
ST, SR Temperature sensor SA, SB Pressure sensor 100 Outdoor control device (temperature calculation means, oil amount determination means)

Claims (7)

一の圧縮機の高圧部と他の圧縮機の低圧部とを接続するオイル管のオイル温度を測定するオイル温度センサと、
前記一の圧縮機の吐出温度、吐出圧力及び吸込圧力に基づいて、前記一の圧縮機の圧縮冷媒が等エンタルピ変化により前記一の圧縮機の吸込圧力の冷媒に変化した場合の温度を算出する温度算出手段と、
この温度算出手段が算出した温度と前記オイル温度センサの測定温度とを比較し、この比較結果に基づいて、前記一の圧縮機内のオイル量が不足しているか否かを判定するオイル量判定手段とを備えたことを特徴とするオイル量判定装置。 An oil temperature sensor for measuring an oil temperature of an oil pipe connecting a high pressure part of one compressor and a low pressure part of another compressor;
Based on the discharge temperature, discharge pressure, and suction pressure of the one compressor, the temperature when the compressed refrigerant of the one compressor is changed to the refrigerant of the suction pressure of the one compressor due to an isenthalpy change is calculated. Temperature calculation means;
Oil amount determination means that compares the temperature calculated by the temperature calculation means with the measured temperature of the oil temperature sensor and determines whether or not the amount of oil in the one compressor is insufficient based on the comparison result An oil amount determination device comprising: 複数の高圧容器の圧縮機を備え、一の圧縮機の高圧部と他の圧縮機の低圧部とを、オイル管で接続した冷凍装置において、
前記オイル管のオイル温度を測定するオイル温度センサと、
前記一の圧縮機の吐出温度、吐出圧力及び吸込圧力に基づいて、前記一の圧縮機の圧縮冷媒が等エンタルピ変化により前記一の圧縮機の吸込圧力の冷媒に変化した場合の温度を算出する温度算出手段と、
この温度算出手段が算出した温度と前記オイル温度センサの測定温度とを比較し、この比較結果に基づいて、前記一の圧縮機内のオイル量が不足しているか否かを判定するオイル量判定手段とを備えたことを特徴とする冷凍装置。 In a refrigeration apparatus comprising a compressor of a plurality of high-pressure vessels, and connecting a high-pressure part of one compressor and a low-pressure part of another compressor with an oil pipe,
An oil temperature sensor for measuring the oil temperature of the oil pipe;
Based on the discharge temperature, discharge pressure, and suction pressure of the one compressor, the temperature when the compressed refrigerant of the one compressor is changed to the refrigerant of the suction pressure of the one compressor due to an isenthalpy change is calculated. Temperature calculation means;
Oil amount determination means that compares the temperature calculated by the temperature calculation means with the measured temperature of the oil temperature sensor and determines whether or not the amount of oil in the one compressor is insufficient based on the comparison result A refrigeration apparatus comprising: 複数の高圧容器の圧縮機を備え、一の圧縮機の高圧部と他の圧縮機の低圧部とを、オイル管で接続した冷凍装置において、
前記オイル管のオイル温度を測定するオイル温度センサと、
前記一の圧縮機の吐出温度を測定する吐出温度センサと、
前記一の圧縮機の吐出圧力及び吸込圧力、並びに前記センサの測定温度に基づいて、前記オイル管を流れる前記一の圧縮機の圧縮冷媒が等エンタルピ変化により前記一の圧縮機の吐出圧力の冷媒に変化した場合の温度を算出する温度算出手段と、
この温度算出手段が算出した温度と前記吐出温度センサの測定温度とを比較し、この比較結果に基づいて、前記一の圧縮機内のオイル量が不足しているか否かを判定するオイル量判定手段とを備えたことを特徴とする冷凍装置。 In a refrigeration apparatus comprising a compressor of a plurality of high-pressure vessels, and connecting a high-pressure part of one compressor and a low-pressure part of another compressor with an oil pipe,
An oil temperature sensor for measuring the oil temperature of the oil pipe;
A discharge temperature sensor for measuring a discharge temperature of the one compressor;
Based on the discharge pressure and suction pressure of the one compressor and the measured temperature of the sensor, the compressed refrigerant of the one compressor flowing through the oil pipe is changed to the refrigerant having the discharge pressure of the one compressor due to an isoenthalpy change. Temperature calculating means for calculating the temperature when changed to
Oil amount determination means that compares the temperature calculated by the temperature calculation means with the measured temperature of the discharge temperature sensor and determines whether or not the amount of oil in the one compressor is insufficient based on the comparison result A refrigeration apparatus comprising: 前記オイル管は、前記一の圧縮機内のオイル量が予め定めたオイルレベル以下の場合に、その圧縮機内の圧縮冷媒が前記オイル管を介して他の圧縮機に流出するように、前記一の圧縮機の所定位置に接続され、
前記オイル量判定手段は、前記一の圧縮機内のオイル量が前記オイルレベル以下か否かを判定することを特徴とする請求項２又は３記載の冷凍装置。 The oil pipe is configured so that when the amount of oil in the one compressor is equal to or lower than a predetermined oil level, the compressed refrigerant in the compressor flows out to the other compressor via the oil pipe. Connected to a predetermined position of the compressor,
The refrigeration apparatus according to claim 2 or 3, wherein the oil amount determination means determines whether or not an oil amount in the one compressor is equal to or lower than the oil level. 前記オイル管は絞りを備え、
前記センサは、前記オイル管の絞りと前記他の圧縮機の低圧部との間の温度を測定することを特徴とする請求項２乃至４のいずれかに記載の冷凍装置。 The oil pipe has a throttle;
The refrigeration apparatus according to any one of claims 2 to 4, wherein the sensor measures a temperature between a throttle of the oil pipe and a low pressure portion of the other compressor. 複数の高圧容器の圧縮機を備え、一の圧縮機の高圧部と他の圧縮機の低圧部とを、オイル管で接続した冷凍装置の制御方法において、
前記一の圧縮機の吐出温度、吐出圧力及び吸込圧力に基づいて、前記一の圧縮機の圧縮冷媒が等エンタルピ変化により前記一の圧縮機の吸込圧力の冷媒に変化した場合の温度を算出する温度算出ステップと、
前記算出した温度と、前記オイル管のオイル温度とを比較し、この比較結果に基づいて、前記一の圧縮機内のオイル量が不足しているか否かを判定するオイル量判定ステップとを備えたことを特徴とする冷凍装置の制御方法。 In a control method of a refrigeration apparatus comprising a compressor of a plurality of high-pressure vessels, and connecting a high-pressure part of one compressor and a low-pressure part of another compressor with an oil pipe,
Based on the discharge temperature, discharge pressure, and suction pressure of the one compressor, the temperature when the compressed refrigerant of the one compressor is changed to the refrigerant of the suction pressure of the one compressor due to an isenthalpy change is calculated. A temperature calculation step;
An oil amount determination step of comparing the calculated temperature with the oil temperature of the oil pipe and determining whether or not the amount of oil in the one compressor is insufficient based on the comparison result; A control method for a refrigeration apparatus. 複数の高圧容器の圧縮機を備え、一の圧縮機の高圧部と他の圧縮機の低圧部とを、オイル管で接続した冷凍装置の制御方法において、
前記一の圧縮機の吐出圧力及び吸込圧力、並びに前記センサの測定温度に基づいて、前記オイル管を流れる前記一の圧縮機の圧縮冷媒が等エンタルピ変化により前記一の圧縮機の吐出圧力の冷媒に変化した場合の温度を算出する温度算出ステップと、
前記算出した温度と前記一の圧縮機の吐出温度とを比較し、この比較結果に基づいて、前記一の圧縮機内のオイル量が不足しているか否かを判定するオイル量判定ステップとを備えたことを特徴とする冷凍装置の制御方法。 In a control method of a refrigeration apparatus comprising a compressor of a plurality of high-pressure vessels, and connecting a high-pressure part of one compressor and a low-pressure part of another compressor with an oil pipe,
Based on the discharge pressure and suction pressure of the one compressor and the measured temperature of the sensor, the compressed refrigerant of the one compressor flowing through the oil pipe is changed to the refrigerant having the discharge pressure of the one compressor due to an isoenthalpy change. A temperature calculating step for calculating the temperature when
An oil amount determination step of comparing the calculated temperature with a discharge temperature of the one compressor and determining whether or not the amount of oil in the one compressor is insufficient based on the comparison result. A control method for a refrigeration apparatus, comprising:
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JP2007040606A (en) * 2005-08-03 2007-02-15 Denso Corp Feedback oil quality determination device and refrigeration cycle device
WO2007139093A1 (en) * 2006-05-31 2007-12-06 Daikin Industries, Ltd. Freezing apparatus
JP2008249231A (en) * 2007-03-30 2008-10-16 Yanmar Co Ltd Air conditioner
WO2013099047A1 (en) * 2011-12-27 2013-07-04 三菱電機株式会社 Air conditioner
JP2016095103A (en) * 2014-11-17 2016-05-26 日立アプライアンス株式会社 Refrigerator

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007040606A (en) * 2005-08-03 2007-02-15 Denso Corp Feedback oil quality determination device and refrigeration cycle device
JP4525515B2 (en) * 2005-08-03 2010-08-18 株式会社デンソー Refrigeration cycle equipment
WO2007139093A1 (en) * 2006-05-31 2007-12-06 Daikin Industries, Ltd. Freezing apparatus
JP2008249231A (en) * 2007-03-30 2008-10-16 Yanmar Co Ltd Air conditioner
WO2013099047A1 (en) * 2011-12-27 2013-07-04 三菱電機株式会社 Air conditioner
CN104011483A (en) * 2011-12-27 2014-08-27 三菱电机株式会社 Air Conditioner
JPWO2013099047A1 (en) * 2011-12-27 2015-04-30 三菱電機株式会社 Air conditioner
CN104011483B (en) * 2011-12-27 2016-05-11 三菱电机株式会社 Conditioner
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JP2016095103A (en) * 2014-11-17 2016-05-26 日立アプライアンス株式会社 Refrigerator

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