JP2009168339A

JP2009168339A - Air conditioner and its control method

Info

Publication number: JP2009168339A
Application number: JP2008007256A
Authority: JP
Inventors: Kojiro Nakamura; 康次郎中村
Original assignee: Calsonic Kansei Corp
Current assignee: Marelli Corp
Priority date: 2008-01-16
Filing date: 2008-01-16
Publication date: 2009-07-30

Abstract

<P>PROBLEM TO BE SOLVED: To determine excess or shortage of the amount of sealed refrigerant at low costs without adding a special component. <P>SOLUTION: This air conditioner comprises a refrigerating cycle having a compressor, a radiator, a pressure reducer and an evaporator, and applying a carbon dioxide gas as a refrigerant, and further comprises a pressure sensor for detecting a discharged refrigerant pressure Pd of the compressor, a first refrigerant temperature sensor for detecting a discharged refrigerant temperature Td of the compressor, and a low pressure-side pressure recognizing means for estimating a refrigerant pressure Ps at a low pressure side of the refrigerating cycle. A maximum allowable discharge refrigerant temperature Td' is determined from the low pressure-side refrigerant pressure Ps recognized by the low pressure-side pressure recognizing means and the discharge refrigerant pressure Pd of the compressor detected by the pressure sensor, and the excess or shortage of the amount of refrigerant sealed in the refrigerating cycle is determined by comparing the allowable discharge refrigerant temperature Td' and the detected discharge refrigerant temperature Td detected by the discharge refrigerant temperature detecting means. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

本発明は、冷媒を封入した冷凍サイクルを備えた空気調和装置及びその制御方法に関する。 The present invention relates to an air conditioner including a refrigeration cycle in which a refrigerant is sealed, and a control method thereof.

この種の従来の空気調和装置としては、特許文献１に開示されたものがある。この空気調和装置は、冷媒を圧縮する圧縮機と、圧縮機で圧縮された冷媒と空気との間で熱交換し、冷媒に放熱させる放熱器と、放熱器で冷却された冷媒を減圧する膨張弁と、膨張弁によって減圧された冷媒と空気との間で熱交換し、冷媒に吸熱させる蒸発器とを有する冷凍サイクルを備えている。又、空気調和装置は、冷凍サイクルの放熱器と膨張弁との間に介在され、高圧側の冷媒圧力を検知する圧力センサと、外気温度を検知する外気温度センサと、外気温度センサが検知した外気温度と圧力センサが検知した高圧側圧力に基づいて封入冷媒量の過少を判定する始動前冷媒不足判定手段とを備えている。 A conventional air conditioner of this type is disclosed in Patent Document 1. This air conditioner includes a compressor that compresses a refrigerant, a heat exchanger that exchanges heat between the refrigerant compressed by the compressor and air, and that radiates heat to the refrigerant, and an expansion that depressurizes the refrigerant cooled by the radiator. A refrigeration cycle having a valve and an evaporator that exchanges heat between the refrigerant decompressed by the expansion valve and the air and absorbs heat by the refrigerant is provided. The air conditioner is interposed between the radiator and the expansion valve of the refrigeration cycle, and is detected by a pressure sensor that detects a refrigerant pressure on the high pressure side, an outside air temperature sensor that detects an outside air temperature, and an outside air temperature sensor. Pre-starting refrigerant shortage determining means for determining whether the amount of the enclosed refrigerant is too low based on the outside air temperature and the high pressure side pressure detected by the pressure sensor.

始動前冷媒不足判定手段は、外気温度に対する冷媒の飽和圧力に基づいて許容冷媒圧力を求め、許容冷媒圧力より実際の高圧側圧力が小さい場合に封入冷媒量が過少であると判定する。 The pre-starting refrigerant shortage determining means obtains the allowable refrigerant pressure based on the refrigerant saturation pressure with respect to the outside air temperature, and determines that the amount of enclosed refrigerant is too small when the actual high-pressure side pressure is smaller than the allowable refrigerant pressure.

この従来例によれば、外気温度に応じて冷媒の飽和圧力が変化することに着目して封入冷媒量の過少を判定するため、外気温度に関わらず封入冷媒量の過少を正確に判定できる。
実開平５−３８６５号公報 According to this conventional example, since it is determined whether or not the amount of the encapsulated refrigerant is small by focusing on the fact that the saturation pressure of the refrigerant changes according to the outside air temperature, it is possible to accurately determine whether or not the amount of the encapsulated refrigerant is small regardless of the outside air temperature.
Japanese Utility Model Publication No. 5-3865

しかしながら、従来例の空気調和装置では、高圧側冷媒圧力に着目して封入冷媒量の過少を判定しているが、例えばシステム容積３１００ｃｍ^３、規定封入量６００ｇとした場合に、冷媒温度が高い場合（例えば２０ｄｅｇＣ）と低い場合（例えば５ｄｅｇＣ）では、飽和圧力が０．２ＭＰａ変化するのに、冷媒温度が高い場合には冷媒量１００ｇ以下の減少で足りるのに、冷媒温度が低い場合には冷媒量２５０ｇ以上の減少が必要である。従って、精度を求めるために圧力センサとして高精度のものを用いないと、誤検知する可能性が高いため、高コストになるという問題があった。 However, in the air conditioning apparatus of the conventional example, the excess refrigerant amount is determined by paying attention to the high-pressure side refrigerant pressure. For example, when the system volume is 3100 cm ³ and the specified enclosure amount is 600 g, the refrigerant temperature is high. When the temperature is low (for example, 20 degC) (for example, 5 degC), the saturation pressure changes by 0.2 MPa, but when the refrigerant temperature is high, a decrease in the refrigerant amount of 100 g or less is sufficient, but when the refrigerant temperature is low, the refrigerant A reduction of more than 250 g is necessary. Therefore, if a high-precision pressure sensor is not used to obtain accuracy, there is a high possibility of erroneous detection, resulting in a high cost.

そこで、本発明は、特別な部品を追加することなく低コストに封入冷媒量の過少を判定できる空気調和装置及びその制御方法を提供することを目的とする。 Then, an object of this invention is to provide the air conditioning apparatus which can determine the amount of enclosure refrigerant | coolants being insufficient, and its control method at low cost, without adding a special component.

上記目的を達成する請求項１の発明は、冷媒を圧縮する圧縮機と、前記圧縮機で圧縮された冷媒と空気との間で熱交換し、冷媒に放熱させる放熱器と、前記放熱器で冷却された冷媒を減圧する減圧手段と、前記減圧手段によって減圧された冷媒と空気との間で熱交換し、冷媒に吸熱させる蒸発器とを少なくとも有する冷凍サイクルを備えた空気調和装置であって、前記圧縮機の吐出冷媒圧力を検知する高圧側圧力検知手段と、前記圧縮機の吐出冷媒温度を検知する吐出冷媒温度検知手段と、前記冷凍サイクルの低圧側の冷媒圧力を認識する低圧側圧力認識手段と、前記低圧側圧力認識手段によって認識した低圧側の冷媒圧力と前記高圧側圧力検知手段が検知した前記圧縮機の吐出冷媒圧力とから最大限許容される許容吐出冷媒温度を求め、この許容吐出冷媒温度と前記吐出冷媒温度検知手段が検知した検知吐出冷媒温度とを比較することにより前記冷凍サイクル内の封入冷媒量が過少であるか否かを判定する冷媒量過少判定手段とを備えたことを備えたことを特徴とする空気調和装置である。 The invention of claim 1 that achieves the above object includes a compressor that compresses a refrigerant, a radiator that exchanges heat between the refrigerant compressed by the compressor and air, and dissipates heat to the refrigerant, and the radiator. An air conditioner including a refrigeration cycle having at least a decompression unit that decompresses a cooled refrigerant, and an evaporator that exchanges heat between the refrigerant decompressed by the decompression unit and air and absorbs heat from the refrigerant. A high pressure side pressure detecting means for detecting a refrigerant pressure discharged from the compressor, a discharge refrigerant temperature detecting means for detecting a refrigerant temperature discharged from the compressor, and a low pressure side pressure recognizing a low pressure side refrigerant pressure of the refrigeration cycle A maximum allowable discharge refrigerant temperature is obtained from the low pressure side refrigerant pressure recognized by the recognition means, the low pressure side pressure recognition means, and the discharge refrigerant pressure of the compressor detected by the high pressure side pressure detection means; Comparing an allowable discharge refrigerant temperature with a detected discharge refrigerant temperature detected by the discharge refrigerant temperature detection means, a refrigerant quantity under-determination means for judging whether or not an amount of enclosed refrigerant in the refrigeration cycle is too small. An air conditioner characterized by comprising the above.

請求項２の発明は、請求項１記載の空気調和装置であって、前記低圧側冷媒圧力認識手段は、前記蒸発器を通過する空気が空調空気とされる冷房モードでは、前記蒸発器を通過した空気温度より低圧側の冷媒圧力を推定することを特徴とする空気調和装置である。 A second aspect of the present invention is the air conditioner according to the first aspect, wherein the low-pressure side refrigerant pressure recognition means passes through the evaporator in a cooling mode in which air passing through the evaporator is conditioned air. It is an air conditioner characterized by estimating the refrigerant | coolant pressure of a low pressure side from the measured air temperature.

請求項３の発明は、請求項１記載の空気調和装置であって、前記低圧側冷媒圧力認識手段は、前記蒸発器を通過する空気が外気とされる暖房モードでは、前記蒸発器が載置される周辺の空気温度より低圧側の冷媒圧力を推定することを特徴とする空気調和装置である。 A third aspect of the present invention is the air conditioning apparatus according to the first aspect, wherein the low-pressure side refrigerant pressure recognition means is configured such that the evaporator is placed in a heating mode in which air passing through the evaporator is outside air. It is an air conditioner characterized by estimating the refrigerant | coolant pressure of a low pressure side from the surrounding air temperature.

請求項４の発明は、請求項１〜請求項３のいずれかに記載の空気調和装置であって、前記冷媒量過少判定手段は、前記圧縮機の稼働開始から一定時間以内に封入冷媒量の過少の判定を行うことを特徴とする空気調和装置である。 Invention of Claim 4 is an air conditioning apparatus in any one of Claims 1-3, Comprising: The said refrigerant | coolant amount low determination means is the amount of enclosed refrigerant | coolants within a fixed time from the operation start of the said compressor. It is an air conditioner characterized by performing an under-determination.

請求項５の発明は、請求項１〜請求項４のいずれかに記載の空気調和装置であって、前記冷媒量過少判定手段は、前記吐出冷媒温度検知手段が検知した検知吐出冷媒温度より前記圧縮機のモータコイル温度が低い場合に、封入冷媒量の過少の判定を行うことを特徴とする空気調和装置である。 Invention of Claim 5 is an air conditioning apparatus in any one of Claims 1-4, Comprising: The said refrigerant | coolant amount under-determination means is said from the detection discharge refrigerant temperature which the said discharge refrigerant temperature detection means detected. When the motor coil temperature of the compressor is low, the air conditioner is characterized by determining whether the amount of the enclosed refrigerant is too low.

請求項６の発明は、請求項１〜請求項５のいずれかに記載の空気調和装置であって、前記冷媒量過少判定手段は、前記吐出冷媒温度検知手段が検知した検知吐出冷媒温度より前記圧縮機のモータコイル温度が高い場合に、許容吐出冷媒温度に前記圧縮機のモータコイル温度を補償した温度値によって封入冷媒量の過少を判定することを特徴とする空気調和装置である。 Invention of Claim 6 is an air conditioning apparatus in any one of Claims 1-5, Comprising: The said refrigerant | coolant amount under-decision means is said from the detection discharge refrigerant temperature which the said discharge refrigerant temperature detection means detected. When the motor coil temperature of the compressor is high, the air conditioner is characterized in that the amount of the enclosed refrigerant is determined based on a temperature value obtained by compensating the motor coil temperature of the compressor with the allowable discharge refrigerant temperature.

請求項７の発明は、請求項１〜請求項６のいずれかに記載の空気調和装置であって、前記冷媒量過少判定手段は、許容吐出冷媒温度に前記圧縮機のモータの印加電力による熱損失温度値を補償した温度値によって封入冷媒量の過少を判定することを特徴とする空気調和装置である。 A seventh aspect of the present invention is the air conditioner according to any one of the first to sixth aspects, wherein the refrigerant amount under-determination means is configured to heat the allowable discharge refrigerant temperature to the allowable discharge refrigerant temperature by the electric power applied to the compressor motor. The air conditioner is characterized in that the amount of the enclosed refrigerant is determined based on a temperature value compensated for the loss temperature value.

請求項８の発明は、冷媒を圧縮する圧縮機と、前記圧縮機で圧縮された冷媒と空気との間で熱交換し、冷媒に放熱させる放熱器と、前記放熱器で冷却された冷媒を減圧する減圧手段と、前記減圧手段によって減圧された冷媒と空気との間で熱交換し、冷媒に吸熱させる蒸発器とを少なくとも有する冷凍サイクルを備えた空気調和装置の制御方法であって、前記圧縮機の吐出冷媒圧力を検知する高圧側圧力検知手段と、前記圧縮機の吐出冷媒温度を検知する吐出冷媒温度検知手段と、前記冷凍サイクルの低圧側の冷媒圧力を認識する低圧側圧力認識手段とを備え、前記低圧側圧力認識手段によって認識した低圧側の冷媒圧力と前記高圧側圧力検知手段が検知した前記圧縮機の吐出冷媒圧力とから最大限許容される許容吐出冷媒温度を求め、この許容吐出冷媒温度と前記吐出冷媒温度検知手段が検知した検知吐出冷媒温度とを比較することにより前記冷凍サイクル内の封入冷媒量が過少であるか否かを判定することを備えたことを特徴とする空気調和装置の制御方法である。 According to an eighth aspect of the present invention, there is provided a compressor that compresses a refrigerant, a heat exchanger that exchanges heat between the refrigerant compressed by the compressor and air, and dissipates heat to the refrigerant, and a refrigerant that is cooled by the radiator. A control method for an air conditioner comprising a refrigeration cycle having at least a decompression unit that decompresses, and an evaporator that exchanges heat between the refrigerant decompressed by the decompression unit and air and absorbs heat by the refrigerant, High pressure side pressure detection means for detecting the discharge refrigerant pressure of the compressor, discharge refrigerant temperature detection means for detecting the discharge refrigerant temperature of the compressor, and low pressure side pressure recognition means for recognizing the refrigerant pressure on the low pressure side of the refrigeration cycle An allowable discharge refrigerant temperature that is allowed to a maximum extent from a low-pressure-side refrigerant pressure recognized by the low-pressure-side pressure recognition means and a discharge refrigerant pressure of the compressor detected by the high-pressure-side pressure detection means, It is characterized by determining whether or not the amount of the enclosed refrigerant in the refrigeration cycle is too small by comparing the discharge refrigerant temperature with the detected discharge refrigerant temperature detected by the discharge refrigerant temperature detection means. It is the control method of the air conditioning apparatus.

請求項９の発明は、請求項８記載の空気調和装置の制御方法であって、前記低圧側冷媒圧力認識手段は、前記蒸発器を通過する空気が空調空気とされる冷房モードでは、前記蒸発器を通過した空気温度より低圧側の冷媒圧力を推定することを特徴とする空気調和装置である。 A ninth aspect of the invention is the control method for an air conditioner according to the eighth aspect, wherein the low-pressure side refrigerant pressure recognition means performs the evaporation in a cooling mode in which air passing through the evaporator is conditioned air. It is an air conditioner characterized by estimating the refrigerant | coolant pressure of a low pressure side from the air temperature which passed the container.

請求項１０の発明は、請求項８記載の空気調和装置の制御方法であって、前記低圧側冷媒圧力認識手段は、前記蒸発器を通過する空気が外気とされる暖房モードでは、前記蒸発器が載置される周辺の空気温度より低圧側の冷媒圧力を推定することを特徴とする空気調和装置の制御方法である。 A tenth aspect of the present invention is the control method for an air conditioner according to the eighth aspect, wherein the low-pressure side refrigerant pressure recognition means is configured such that in the heating mode in which the air passing through the evaporator is outside air, the evaporator This is a control method for an air conditioner, wherein the refrigerant pressure on the low-pressure side is estimated from the temperature of the surrounding air.

請求項１１の発明は、請求項８〜請求項１０のいずれかに記載の空気調和装置の制御方法であって、前記圧縮機の稼働開始から一定時間以内に封入冷媒量の過少の判定を行うことを特徴とする空気調和装置の制御方法である。 The invention according to claim 11 is the control method for an air conditioner according to any one of claims 8 to 10, wherein the determination of whether the amount of the enclosed refrigerant is too small is made within a certain time from the start of operation of the compressor. It is the control method of the air conditioning apparatus characterized by this.

請求項１２の発明は、請求項８〜請求項１１のいずれかに記載の空気調和装置の制御方法であって、前記吐出冷媒温度検知手段が検知した検知吐出冷媒温度より前記圧縮機のモータコイル温度が低い場合に、封入冷媒量の過少の判定を行うことを特徴とする空気調和装置の制御方法である。 A twelfth aspect of the invention is a method for controlling an air conditioner according to any one of the eighth to eleventh aspects, wherein the motor coil of the compressor is detected from the detected discharge refrigerant temperature detected by the discharge refrigerant temperature detection means. A control method for an air conditioner characterized in that when the temperature is low, the amount of the enclosed refrigerant is determined to be insufficient.

請求項１３の発明は、請求項８〜請求項１２のいずれかに記載の空気調和装置の制御方法であって、前記吐出冷媒温度検知手段が検知した検知吐出冷媒温度より前記圧縮機のモータコイル温度が高い場合に、許容吐出冷媒温度に前記圧縮機のモータコイル温度を補償した温度値によって封入冷媒量の過少を判定することを特徴とする空気調和装置の制御方法である。 A thirteenth aspect of the present invention is the control method for an air conditioner according to any one of the eighth to twelfth aspects, wherein the motor coil of the compressor is detected from the detected discharged refrigerant temperature detected by the discharged refrigerant temperature detecting means. When the temperature is high, the control method of the air conditioner is characterized in that the amount of the enclosed refrigerant is determined based on a temperature value obtained by compensating the motor coil temperature of the compressor with the allowable discharge refrigerant temperature.

請求項１４の発明は、請求項８〜請求項１３のいずれかに記載の空気調和装置の制御方法であって、許容吐出冷媒温度に前記圧縮機のモータの印加電力による熱損失温度値を補償した温度値によって封入冷媒量の過少を判定することを特徴とする空気調和装置の制御方法。 The invention of claim 14 is the method of controlling an air conditioner according to any one of claims 8 to 13, wherein the allowable discharge refrigerant temperature is compensated for the heat loss temperature value due to the electric power applied to the motor of the compressor. A control method for an air conditioner, wherein a determination is made as to whether the amount of the encapsulated refrigerant is excessive or not based on the measured temperature value.

請求項１の発明によれば、冷凍サイクルの低圧側圧力に圧縮機の吸入過熱度（スーパーヒート）と断熱効率を規定すると、圧縮機の吐出冷媒圧力（冷凍サイクルの高圧側圧力）に対する圧縮機の吐出冷媒温度が物性的に求まるが、冷凍サイクル内の封入冷媒量が過少状態になると、圧縮機の吸入過熱度の増大と断熱効率の低下をもたらすことから許容可能な圧縮機の吐出冷媒温度を求めることができる。このことに着目して、低圧側圧力認識手段より低圧側の冷媒圧力を認識し、高圧側圧力検知手段により圧縮機の実際の吐出冷媒圧力を検知し、これらから最大限許容される許容吐出冷媒温度を求め、この許容吐出冷媒温度と検知吐出冷媒温度とを比較することにより冷凍サイクル内の封入冷媒量が過少であるか否かを判定する。従って、封入冷媒量の過少判定を外気温度に基づく圧力レベルによって判定するのではないため、高精度な圧力センサを用いる必要がないと共に、必要とする検知情報は空気調和装置に通常付設される検知手段を用いて得ることができる。従って、特別な部品を追加することなく低コストに封入冷媒量の過少を判定できる。 According to the invention of claim 1, when the suction superheat degree (superheat) and the heat insulation efficiency of the compressor are defined in the low pressure side pressure of the refrigeration cycle, the compressor with respect to the refrigerant discharge refrigerant pressure (high pressure side pressure of the refrigeration cycle) The discharge refrigerant temperature of the compressor can be obtained physically, but if the amount of the enclosed refrigerant in the refrigeration cycle becomes too small, the intake superheat degree of the compressor will increase and the adiabatic efficiency will decrease, so the allowable discharge refrigerant temperature of the compressor Can be requested. Paying attention to this, the low pressure side pressure recognition means recognizes the low pressure side refrigerant pressure, the high pressure side pressure detection means detects the actual discharge refrigerant pressure of the compressor, and the maximum allowable discharge refrigerant from these. The temperature is obtained, and it is determined whether or not the amount of the enclosed refrigerant in the refrigeration cycle is too small by comparing the allowable discharge refrigerant temperature and the detected discharge refrigerant temperature. Therefore, it is not necessary to use a high-precision pressure sensor because the determination of the amount of the enclosed refrigerant amount is not based on the pressure level based on the outside air temperature, and the necessary detection information is a detection usually attached to the air conditioner. It can be obtained using means. Therefore, it is possible to determine whether the amount of the enclosed refrigerant is too low at a low cost without adding special parts.

請求項２及び請求項９の発明によれば、蒸発器を通過した空気の温度を検知するための温度センサを利用して冷凍サイクルの低圧側の圧力を推定する。従って、冷凍サイクルの低圧側の圧力を認識するのに、冷凍サイクルの冷圧側に圧力センサを付設する必要がないため、システムのシンプル化、コスト削減等になる。 According to invention of Claim 2 and Claim 9, the pressure of the low pressure side of a refrigerating cycle is estimated using the temperature sensor for detecting the temperature of the air which passed the evaporator. Therefore, in order to recognize the pressure on the low pressure side of the refrigeration cycle, it is not necessary to attach a pressure sensor on the cold pressure side of the refrigeration cycle, which simplifies the system and reduces costs.

請求項３及び請求項１０の発明によれば、蒸発器が設置される周辺の空気温度を検知するための温度センサを利用して冷凍サイクルの低圧側の圧力を推定する。従って、冷凍サイクルの低圧側の圧力を認識するのに、冷凍サイクルの冷圧側に圧力センサを付設する必要がないため、システムのシンプル化、コスト削減等になる。 According to the third and tenth aspects of the present invention, the pressure on the low pressure side of the refrigeration cycle is estimated using the temperature sensor for detecting the temperature of the air around the evaporator. Therefore, in order to recognize the pressure on the low pressure side of the refrigeration cycle, it is not necessary to attach a pressure sensor on the cold pressure side of the refrigeration cycle, which simplifies the system and reduces costs.

請求項４及び請求項１１の発明によれば、圧縮機の稼働時の熱による悪影響を受けることなく、封入冷媒量の過少を正確に判定できる。 According to the fourth and eleventh aspects of the present invention, it is possible to accurately determine whether the amount of the enclosed refrigerant is insufficient without being adversely affected by heat during operation of the compressor.

請求項５及び請求項１２の発明によれば、圧縮機のモータコイルの熱による悪影響を受けることなく、封入冷媒量の過少を判定できる。 According to the fifth and twelfth aspects of the present invention, it is possible to determine whether the amount of the enclosed refrigerant is too low without being adversely affected by the heat of the motor coil of the compressor.

請求項６及び請求項１３の発明によれば、圧縮機の稼働中であれば、封入冷媒量の過少判定の時期を制限されることなく、圧縮機のモータコイルの熱による影響を受けない正確な判定ができる。 According to the sixth and thirteenth aspects of the present invention, if the compressor is in operation, the timing for determining the underfilled refrigerant amount is not limited, and the compressor is not affected by the heat of the motor coil accurately. Can be judged.

請求項７及び請求項１４の発明によれば、圧縮機の稼働中であれば、封入冷媒量の過少判定の時期を制限されることなく、圧縮機のモータコイルの熱による影響を受けない正確な判定ができる。 According to the seventh and fourteenth aspects of the present invention, if the compressor is in operation, the timing for determining the underfilled refrigerant amount is not limited, and the compressor is not affected by the heat of the motor coil accurately. Judgment can be made.

以下、本発明の実施の形態を図面に基づいて説明する。 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

（実施の形態）
図１〜図５は本発明の実施の形態を示し、図１は車両用空気調和装置の構成図、図２は本発明の制御に関わる部分の回路ブロック図、図３はモリエル線図と冷凍サイクルの挙動線図、図４は冷却モード時における封入冷媒量の過少判定フローチャート、図５は暖房モード時における封入冷媒量の過少判定フローチャートである。 (Embodiment)
1 to 5 show an embodiment of the present invention, FIG. 1 is a block diagram of a vehicle air conditioner, FIG. 2 is a circuit block diagram of a part related to the control of the present invention, and FIG. 3 is a Mollier diagram and a refrigeration. FIG. 4 is a flow chart of cycle behavior, FIG. 4 is a flowchart for determining the amount of the enclosed refrigerant in the cooling mode, and FIG. 5 is a flowchart for determining the amount of the enclosed refrigerant in the heating mode.

図１に示すように、空気調和装置である車両用空気調和装置１は、冷凍サイクル２を有する。この冷凍サイクル２は、冷房と暖房を兼用できるものであり、超臨界冷媒である炭酸ガス（例えばＲ７４４）を冷媒とする。 As shown in FIG. 1, a vehicle air conditioner 1 that is an air conditioner has a refrigeration cycle 2. The refrigeration cycle 2 can be used for both cooling and heating, and uses carbon dioxide gas (for example, R744), which is a supercritical refrigerant, as a refrigerant.

冷凍サイクル２は、炭酸ガスからなる冷媒を圧縮する圧縮機３と、空調ダクト４０内で、且つ、エアミックスドア４１より上流に配置された室内熱交換器４と、空調ダクト４０内で、且つ、エアミックスドア４１より下流に配置された室内放熱器５と、エンジンルーム内に配置された室外熱交換器６と、高圧側の冷媒と低圧側の冷媒間で熱交換させる内部熱交換器７と、冷媒を減圧し、減圧レベルが外部からの制御によって調整可能な減圧手段である第１減圧器８及び第２減圧器９と、冷凍サイクル２内の余分な冷媒を一時的に溜め、且つ、圧縮機３にガス冷媒のみを戻すためのアキュムレータ１０と、冷媒を冷房モード時と暖房モード時で異なる循環経路を通って循環させる三方弁１１、電磁弁１２及び複数の逆止弁１３，１４，１５とを備えている。 The refrigeration cycle 2 includes a compressor 3 for compressing a refrigerant made of carbon dioxide, an air conditioning duct 40, an indoor heat exchanger 4 disposed upstream of the air mix door 41, an air conditioning duct 40, and , The indoor radiator 5 disposed downstream of the air mix door 41, the outdoor heat exchanger 6 disposed in the engine room, and the internal heat exchanger 7 for exchanging heat between the high-pressure side refrigerant and the low-pressure side refrigerant. The first decompressor 8 and the second decompressor 9 which are decompression means that decompress the refrigerant and the decompression level can be adjusted by external control, and temporarily accumulate excess refrigerant in the refrigeration cycle 2, and , An accumulator 10 for returning only the gas refrigerant to the compressor 3, a three-way valve 11, a solenoid valve 12, and a plurality of check valves 13, 14 for circulating the refrigerant through different circulation paths in the cooling mode and the heating mode. , 15 and Eteiru.

第１減圧器８及び第２減圧器９の開閉状態（減圧レベル）、三方弁１１及び電磁弁１２の切替位置は、下記する制御部３０（図２に示す）によって制御される。 The open / close state (pressure reduction level) of the first pressure reducer 8 and the second pressure reducer 9 and the switching position of the three-way valve 11 and the electromagnetic valve 12 are controlled by a control unit 30 (shown in FIG. 2) described below.

具体的には、冷房モードが選択されると、第２減圧器９が閉状態に、三方弁１１及び電磁弁１２が冷媒を室外熱交換器６に流す切替位置とされる。これによって、冷房モード時では、圧縮機３で圧縮された冷媒は、室内放熱器５、室外熱交換器６、内部熱交換器７、第１減圧器８、室内熱交換器４、内部熱交換器７を通る経路で循環する。圧縮機３より吐出された高温高圧の冷媒は、室内放熱器５、室外熱交換器６で放熱される。室内放熱器５は、冷媒と空調ダクト４０内を通過する空気との間で熱交換させて冷媒に放熱させる。冷媒の放熱によって、空調ダクト４０内を通過する空気は暖風とされる。又、室外熱交換器６は、冷媒と外気との間で熱交換させて冷媒に放熱させる。つまり、室外熱交換器６は、冷房モード時には、室内放熱器５と共に放熱器として使用される。内部熱交換器７で高圧側の冷媒と低圧側の冷媒間で熱交換される。内部熱交換器７から出た冷媒は、第１減圧器８で減圧されて室内熱交換器４に入る。室内熱交換器４は、冷媒と空調ダクト４０内を通過する空気との間で熱交換させて冷媒に吸熱させる。冷媒の吸熱によって、空調ダクト４０内を通過する空気は冷風とされる。つまり、室内熱交換器４は、冷房モード時には蒸発器として使用される。冷房モード時には、空調ダクト４０内を流れる空気は、室内熱交換器４によって作成された冷風と室内放熱器５によって作成された暖風との割合がエアミックスドア４１によって調整されることによって所望温度の冷風となって車室内に吹き出される。 Specifically, when the cooling mode is selected, the second pressure reducer 9 is closed, and the three-way valve 11 and the electromagnetic valve 12 are set to a switching position where the refrigerant flows to the outdoor heat exchanger 6. Thus, in the cooling mode, the refrigerant compressed by the compressor 3 is converted into the indoor radiator 5, the outdoor heat exchanger 6, the internal heat exchanger 7, the first decompressor 8, the indoor heat exchanger 4, and the internal heat exchange. It circulates along the path through the vessel 7. The high-temperature and high-pressure refrigerant discharged from the compressor 3 is radiated by the indoor radiator 5 and the outdoor heat exchanger 6. The indoor radiator 5 causes the refrigerant to radiate heat by exchanging heat between the refrigerant and the air passing through the air conditioning duct 40. The air passing through the air conditioning duct 40 is heated by the heat release of the refrigerant. The outdoor heat exchanger 6 exchanges heat between the refrigerant and the outside air to dissipate heat to the refrigerant. That is, the outdoor heat exchanger 6 is used as a radiator together with the indoor radiator 5 in the cooling mode. Heat is exchanged between the high-pressure side refrigerant and the low-pressure side refrigerant in the internal heat exchanger 7. The refrigerant discharged from the internal heat exchanger 7 is decompressed by the first decompressor 8 and enters the indoor heat exchanger 4. The indoor heat exchanger 4 causes the refrigerant to absorb heat by exchanging heat between the refrigerant and the air passing through the air conditioning duct 40. The air passing through the air conditioning duct 40 is cooled by the heat absorbed by the refrigerant. That is, the indoor heat exchanger 4 is used as an evaporator in the cooling mode. In the cooling mode, the air flowing in the air conditioning duct 40 is adjusted to a desired temperature by adjusting the ratio of the cold air created by the indoor heat exchanger 4 and the warm air created by the indoor radiator 5 by the air mix door 41. The cold wind is blown into the passenger compartment.

暖房モードが選択されると、第１減圧器８が閉状態に、三方弁１１及び電磁弁１２が冷媒を内部熱交換器７に流す切替位置とされる。これによって、暖房モード時では、圧縮機３で圧縮された冷媒は、室内放熱器５、内部熱交換器７、第２減圧器９、室外熱交換器６、内部熱交換器７を通る経路で循環する。圧縮機３より吐出された高温高圧の冷媒は、室内放熱器５で放熱される。室内放熱器５は、冷媒と空調ダクト４０内を通過する空気との間で熱交換させて冷媒に放熱させる。これにより、空調ダクト４０内を通過する空気が暖風とされる。内部熱交換器７で高圧側の冷媒と低圧側の冷媒間で熱交換される。内部熱交換器７から出た冷媒は、第２減圧器９で減圧されて室外熱交換器６に入り、ここで室外熱交換器６を通過する外気と熱交換して吸熱される。つまり、室外熱交換器６は、暖房モード時には蒸発器として使用される。暖房モード時には、空調ダクト４０内を流れる空気と室内放熱器５によって作成される暖風との割合がエアミックスドア４１によって調整されることによって所望温度の暖風となって車室内に吹き出される。 When the heating mode is selected, the first pressure reducer 8 is closed, and the three-way valve 11 and the electromagnetic valve 12 are set to a switching position where the refrigerant flows to the internal heat exchanger 7. Thereby, in the heating mode, the refrigerant compressed by the compressor 3 passes through the indoor radiator 5, the internal heat exchanger 7, the second decompressor 9, the outdoor heat exchanger 6, and the internal heat exchanger 7. Circulate. The high-temperature and high-pressure refrigerant discharged from the compressor 3 is radiated by the indoor radiator 5. The indoor radiator 5 causes the refrigerant to radiate heat by exchanging heat between the refrigerant and the air passing through the air conditioning duct 40. As a result, the air passing through the air conditioning duct 40 is heated. Heat is exchanged between the high-pressure side refrigerant and the low-pressure side refrigerant in the internal heat exchanger 7. The refrigerant discharged from the internal heat exchanger 7 is decompressed by the second decompressor 9 and enters the outdoor heat exchanger 6 where heat is exchanged with the outside air passing through the outdoor heat exchanger 6 and absorbed. That is, the outdoor heat exchanger 6 is used as an evaporator in the heating mode. In the heating mode, the ratio of the air flowing through the air-conditioning duct 40 and the warm air created by the indoor radiator 5 is adjusted by the air mix door 41 so that warm air of a desired temperature is blown into the vehicle interior. .

また、車両用空気調和装置１には、冷凍サイクル２の運転状況を検知するための各種のセンサが付設されている。冷媒圧力を検知するものとしては、冷凍サイクル２の高圧側の冷媒圧力を検知する高圧側圧力検知手段である圧力センサ２０が圧縮機３の冷媒吐出側に設けられている。冷媒温度を検知するものとしては、圧縮機３の吐出冷媒温度を検知する吐出冷媒温度検知手段である第１冷媒温度センサ２１と、室内放熱器５の出口冷媒温度を検知する第２冷媒温度センサ２２と、冷房時に室外熱交換器６の出口冷媒温度を検知する第３冷媒温度センサ２３とが設けられている。空気温度を検知するものとしては、室内放熱器５を通過した空気の温度を検知する第１空気温度センサ２４と、室外熱交換器６が設置された周囲の空気温度（外気温度）を検知する第２空気温度センサ２５と、室内熱交換器４を通過した空気の温度を検知する第３空気温度センサ２６が設けられている。 In addition, the vehicle air conditioner 1 is provided with various sensors for detecting the operation status of the refrigeration cycle 2. For detecting the refrigerant pressure, a pressure sensor 20 which is a high-pressure side pressure detecting means for detecting the refrigerant pressure on the high-pressure side of the refrigeration cycle 2 is provided on the refrigerant discharge side of the compressor 3. The refrigerant temperature is detected by a first refrigerant temperature sensor 21 which is a discharge refrigerant temperature detecting means for detecting a refrigerant temperature discharged from the compressor 3 and a second refrigerant temperature sensor which detects an outlet refrigerant temperature of the indoor radiator 5. 22 and a third refrigerant temperature sensor 23 for detecting the outlet refrigerant temperature of the outdoor heat exchanger 6 during cooling. For detecting the air temperature, the first air temperature sensor 24 that detects the temperature of the air that has passed through the indoor radiator 5 and the ambient air temperature (outside air temperature) where the outdoor heat exchanger 6 is installed are detected. A second air temperature sensor 25 and a third air temperature sensor 26 that detects the temperature of the air that has passed through the indoor heat exchanger 4 are provided.

これら各種のセンサ２０〜２６の出力は、制御部３０に導かれている。制御部３０は、これらセンサ２０〜２６の検知情報、ユーザの空調入力情報等に基づいて圧縮機３、第１減圧器８、第２減圧器９、三方弁１１、電磁弁１２等を制御する。例えば、冷房モード時には、第３冷媒温度センサ２３より冷媒温度を検知し、当該冷媒温度に最適な高圧側の圧力となるよう第１減圧器８の開度を制御し、又、第３空気温度センサ２６より室内熱交換器４（蒸発器）を通過した空気温度を検知し、当該空気温度を基にシステム性能（圧縮機３の吐出冷媒量、空調ダクト４０内の図示しない送風ファンの風量等）を制御する。暖房モード時には、第２冷媒温度センサ２２より冷媒温度を検知し、当該冷媒温度に最適な高圧側の圧力となるよう第２減圧器９の開度を制御し、又、第１空気温度センサ２４より室内放熱器５を通過した空気温度を検知し、当該空気温度を基にシステム性能（圧縮機３の吐出冷媒量、空調ダクト４０内の図示しない送風ファンの風量等）を制御する。第１冷媒温度センサ２１より圧縮機３の吐出冷媒温度を検知し、圧縮機３が異常高温にならないよう制御する。 Outputs of these various sensors 20 to 26 are guided to the control unit 30. The control unit 30 controls the compressor 3, the first pressure reducer 8, the second pressure reducer 9, the three-way valve 11, the electromagnetic valve 12, and the like based on the detection information of the sensors 20 to 26, the user air conditioning input information, and the like. . For example, in the cooling mode, the refrigerant temperature is detected by the third refrigerant temperature sensor 23, the opening degree of the first pressure reducer 8 is controlled so that the pressure on the high-pressure side is optimal for the refrigerant temperature, and the third air temperature The air temperature that has passed through the indoor heat exchanger 4 (evaporator) is detected by the sensor 26, and the system performance (the amount of refrigerant discharged from the compressor 3, the air volume of a blower fan (not shown) in the air conditioning duct 40, etc.) based on the air temperature. ) To control. In the heating mode, the refrigerant temperature is detected by the second refrigerant temperature sensor 22, the opening of the second pressure reducer 9 is controlled so that the pressure on the high-pressure side is optimal for the refrigerant temperature, and the first air temperature sensor 24 is used. Further, the temperature of the air that has passed through the indoor radiator 5 is detected, and the system performance (the amount of refrigerant discharged from the compressor 3, the air volume of a blower fan (not shown) in the air conditioning duct 40, etc.) is controlled based on the air temperature. The first refrigerant temperature sensor 21 detects the refrigerant temperature discharged from the compressor 3 and controls so that the compressor 3 does not reach an abnormally high temperature.

制御部３０は、図２に示すように、低圧側冷媒圧力認識手段３０ａを内蔵する。低圧側冷媒圧力認識手段３０ａは、室内熱交換器４を通過する空気が空調空気とされる冷房モードでは、室内熱交換器４を通過した空気温度を第３空気温度センサ２６より取得し、取得した空気温度Ｔｉｎｔより低圧側の冷媒圧力を推定する。つまり、室内熱交換器４を通過した空気温度Ｔｉｎｔと、室内熱交換器４の出口冷媒温度とは相関関係にあり、例えばＴｉｎｔ−３Ｋ（３℃）≒室内熱交換器４の出口冷媒温度と推定できる。そして、室内熱交換器４を出た冷媒は飽和状態であるため、Ｔｉｎｔ−３Ｋでの飽和圧力が低圧側圧力Ｐｓと推定できる。 As shown in FIG. 2, the control unit 30 incorporates a low-pressure side refrigerant pressure recognition means 30a. In the cooling mode in which the air passing through the indoor heat exchanger 4 is conditioned air, the low pressure side refrigerant pressure recognizing means 30a acquires the air temperature that has passed through the indoor heat exchanger 4 from the third air temperature sensor 26, and acquires it. The refrigerant pressure on the low pressure side is estimated from the air temperature Tint. That is, the air temperature Tint that has passed through the indoor heat exchanger 4 and the outlet refrigerant temperature of the indoor heat exchanger 4 are correlated, for example, Tint-3K (3 ° C.) ≈the outlet refrigerant temperature of the indoor heat exchanger 4 Can be estimated. And since the refrigerant | coolant which exited the indoor heat exchanger 4 is a saturated state, the saturation pressure in Tint-3K can be estimated to be the low pressure side pressure Ps.

又、低圧側冷媒圧力認識手段３０ａは、室外熱交換器６を通過する空気が外気とされる暖房モードでは、室外熱交換器６が載置される周辺の空気温度を第２空気温度センサ２５より取得し、取得した空気温度Ｔａｍｂより低圧側の冷媒圧力を推定する。つまり、基本的には外気温度Ｔａｍｂと室外熱交換器６の出口冷媒温度は相関関係にあり、例えば、実験結果よりＴａｍｂ−１２Ｋ（１２℃）≒室外熱交換器６の出口冷媒温度とすることができる。そして、室外熱交換器６の出口冷媒は飽和状態であるため、Ｔａｍｂ−１２Ｋでの飽和圧力が低圧側圧力と推定できる。より詳細には、室外熱交換器６の出口から圧縮機３の吸入位置までの圧力損失を考慮して低圧側圧力Ｐｓを推定する。 In the heating mode in which the air passing through the outdoor heat exchanger 6 is outside air, the low pressure side refrigerant pressure recognizing means 30a determines the temperature of the air around the outdoor heat exchanger 6 on the second air temperature sensor 25. And the refrigerant pressure on the lower pressure side than the acquired air temperature Tamb is estimated. That is, basically, the outdoor air temperature Tamb and the outlet refrigerant temperature of the outdoor heat exchanger 6 have a correlation, for example, Tamb-12K (12 ° C.) ≈outlet refrigerant temperature of the outdoor heat exchanger 6 from the experimental results. Can do. And since the exit refrigerant | coolant of the outdoor heat exchanger 6 is a saturated state, the saturation pressure in Tam-12K can be estimated as a low pressure side pressure. More specifically, the low pressure side pressure Ps is estimated in consideration of the pressure loss from the outlet of the outdoor heat exchanger 6 to the suction position of the compressor 3.

また、制御部３０は、冷媒量過少判定手段３０ｂを内蔵する。冷媒量過少判定手段３０ｂは、冷凍サイクル２の高圧側の圧力Ｐｄと推定した低圧側の圧力Ｐｓを基に、圧縮機３の吸入過熱度（スーパーヒート）と断熱効率より最大限許容される圧縮機３の許容吐出冷媒温度Ｔｄ’を算出する。 Moreover, the control part 30 incorporates the refrigerant | coolant amount low determination means 30b. The refrigerant amount under-determination means 30b is based on the high pressure side pressure Pd of the refrigeration cycle 2 and the low pressure side pressure Ps, and the maximum allowable compression is based on the suction superheat degree (superheat) of the compressor 3 and the adiabatic efficiency. An allowable discharge refrigerant temperature Td ′ of the machine 3 is calculated.

ここで、圧縮機３の許容吐出冷媒温度Ｔｄ’を算出できる理由を説明する。図３において、冷凍サイクル２の低圧側圧力Ｐｓに圧縮機３の吸入過熱度ＳＨ１と断熱効率（図３ではＣ１線の傾斜角度α１によって現れる）を規定すると、圧縮機３の吐出冷媒圧力Ｐｄ（冷凍サイクル２の高圧側圧力）に対する圧縮機３の吐出冷媒温度Ｔｄが物性的に求まる。これを利用して圧縮機３の許容吐出冷媒温度Ｔｄ’を算出する。 Here, the reason why the allowable discharge refrigerant temperature Td 'of the compressor 3 can be calculated will be described. In FIG. 3, when the suction superheat degree SH1 and the heat insulation efficiency (shown by the inclination angle α1 of the C1 line in FIG. 3) are defined as the low pressure Ps of the refrigeration cycle 2, the discharge refrigerant pressure Pd ( The discharge refrigerant temperature Td of the compressor 3 with respect to the high-pressure side pressure of the refrigeration cycle 2 is obtained physically. Using this, the allowable discharge refrigerant temperature Td 'of the compressor 3 is calculated.

ここで、冷凍サイクル２内の封入冷媒量が過少状態になると、圧縮機３の吸入過熱度の増大（図３のＳＨ１→ＳＨ２）と断熱効率の低下（図３のα１→α２）をもたらし、その結果として圧縮機３の吐出冷媒温度Ｔｄが上昇する。このことに着目して、冷媒量過少判定手段３０ｂが封入冷媒量の過少を判定する。以上のことを図３を用いて説明する。図３において、理想的な圧縮機３の吸入過熱度をＳＨ１、断熱圧縮を傾斜角α１とした場合、圧縮機３の吐出冷媒温度Ｐｔはｔ１となる。冷媒封入量が許容できる最低封入量の場合、圧縮機３の吸入過熱度がＳＨ１からＳＨ２に増大し、断熱効率がα１からα２に低下するものとする。これによって、許容吐出冷媒温度Ｔｄ’としてｔ３が算出される。このｔ３は、圧縮機３の性能等より決定される。検知吐出冷媒温度Ｔｄがｔ３を越えれば（例えば図３のｔ４）、封入冷媒量の過少と判定する。検知吐出冷媒温度Ｔｄがｔ３を越えなければ（例えば図３のｔ２）、過少でないと判定する。 Here, when the amount of the enclosed refrigerant in the refrigeration cycle 2 becomes too small, the intake superheat degree of the compressor 3 increases (SH1 → SH2 in FIG. 3) and the heat insulation efficiency decreases (α1 → α2 in FIG. 3). As a result, the discharge refrigerant temperature Td of the compressor 3 increases. Paying attention to this, the refrigerant amount under-determining means 30b determines whether the amount of the enclosed refrigerant is too small. The above will be described with reference to FIG. In FIG. 3, when the ideal superheat degree of the compressor 3 is SH1 and the adiabatic compression is the inclination angle α1, the discharged refrigerant temperature Pt of the compressor 3 is t1. When the refrigerant charging amount is an allowable minimum charging amount, the suction superheat degree of the compressor 3 increases from SH1 to SH2, and the heat insulation efficiency decreases from α1 to α2. Thus, t3 is calculated as the allowable discharge refrigerant temperature Td '. This t3 is determined by the performance of the compressor 3 and the like. If the detected discharge refrigerant temperature Td exceeds t3 (eg, t4 in FIG. 3), it is determined that the amount of enclosed refrigerant is too small. If the detected discharge refrigerant temperature Td does not exceed t3 (for example, t2 in FIG. 3), it is determined that it is not too low.

制御部３０は、冷房モード時には図４のフローチャートを、暖房モード時には図５のフローチャートをそれぞれ実行して冷凍サイクル２の封入冷媒量の過少を判定する。封入冷媒量が過少と判定した場合には、圧縮機３の停止、必要に応じて表示、アラーム等の報知手段３１に出力する。 The control unit 30 executes the flowchart of FIG. 4 in the cooling mode, and executes the flowchart of FIG. 5 in the heating mode, respectively, to determine whether the amount of refrigerant enclosed in the refrigeration cycle 2 is too small. When it is determined that the amount of the enclosed refrigerant is too small, the compressor 3 is stopped, and if necessary, it is output to a notification means 31 such as a display or an alarm.

次に、冷房モード時における封入冷媒量の判定動作を説明する。図４において、圧縮機３が稼働中であるか否かをチェックし（ステップＳ０）、稼働中でなければ稼働中になるまで待つ。圧縮機３が稼働中であることを条件として、圧力センサ２０より冷凍サイクル２の高圧側冷媒圧力Ｐｄ、第１冷媒温度センサ２１より冷凍サイクル２の高圧側冷媒温度Ｔｄ、第３空気温度センサ２６より室内熱交換器４を通過した空気温度Ｔｉｎｔを検知する（ステップＳ１０）。次に、第３空気温度センサ２６の検知温度より低圧側の冷媒圧力Ｐｓを推定する（ステップＳ１１）。次に、高圧側の冷媒圧力Ｐｄと推定した低圧側の冷媒圧力Ｐｓを基に、圧縮機３の吸入過熱度と断熱効率より許容冷媒吐出温度Ｔｄ’を算出する。例えば、圧縮機３の吸入過熱度３５ｄｅｇ、断熱効率７５％を規定し、その時の圧縮機３の吐出冷媒圧力Ｐｄに対する圧縮機３の吐出冷媒温度Ｔｄ’を算出する。空気温度Ｔｉｎｔが３ｄｅｇＣにおいて、吐出冷媒圧力Ｐｄが８ＭＰ時の場合は１１６ｄｅｇＣ、８．５ＭＰ時の場合は１２２ｄｅｇＣというように、空気温度Ｔｉｎｔが５ｄｅｇＣにおいて、吐出冷媒圧力Ｐｄが８ＭＰ時の場合は１１２ｄｅｇＣ、８．５ＭＰ時の場合は１１８ｄｅｇＣというように例えば算出される。 Next, the operation for determining the amount of enclosed refrigerant in the cooling mode will be described. In FIG. 4, it is checked whether or not the compressor 3 is in operation (step S0). On condition that the compressor 3 is in operation, the high pressure side refrigerant pressure Pd of the refrigeration cycle 2 from the pressure sensor 20, the high pressure side refrigerant temperature Td of the refrigeration cycle 2 from the first refrigerant temperature sensor 21, and the third air temperature sensor 26. The air temperature Tint that has passed through the indoor heat exchanger 4 is detected (step S10). Next, the refrigerant pressure Ps on the lower pressure side than the temperature detected by the third air temperature sensor 26 is estimated (step S11). Next, the allowable refrigerant discharge temperature Td ′ is calculated from the suction superheat degree of the compressor 3 and the adiabatic efficiency based on the low-pressure side refrigerant pressure Ps estimated as the high-pressure side refrigerant pressure Pd. For example, the suction superheat degree 35 deg of the compressor 3 and the heat insulation efficiency 75% are defined, and the discharge refrigerant temperature Td ′ of the compressor 3 with respect to the discharge refrigerant pressure Pd of the compressor 3 at that time is calculated. When the air temperature Tint is 3 degC and the discharge refrigerant pressure Pd is 8 MP, 116 degC, when the discharge refrigerant pressure Pd is 8.5 MP, 122 degC, and when the air temperature Tint is 5 degC and the discharge refrigerant pressure Pd is 8 MP, 112 degC, In the case of 8.5 MP, for example, 118 degC is calculated.

次に、圧縮機３の実際の吐出冷媒温度Ｔｄと算出した許容吐出冷媒温度Ｔｄ’とを比較し（ステップＳ１３）、Ｔｄ’よりＴｄが越えた値であれば、冷媒量が過少であると判定する（ステップＳ１４）。冷媒量が過少と判定した場合には、圧縮機３を停止すると共に報知手段３１によって冷媒量の過少を知らせるべく出力する。Ｔｄの値がＴｄ’の値以下であれば、冷媒量が過少でないと判定し、上述した動作を繰り返す。 Next, the actual discharge refrigerant temperature Td of the compressor 3 is compared with the calculated allowable discharge refrigerant temperature Td ′ (step S13), and if the value exceeds Td from Td ′, the refrigerant amount is too small. Determination is made (step S14). When it is determined that the refrigerant amount is too small, the compressor 3 is stopped and the notification means 31 outputs to notify that the refrigerant amount is insufficient. If the value of Td is equal to or less than the value of Td ', it is determined that the refrigerant amount is not too small, and the above-described operation is repeated.

次に、暖房モード時における封入冷媒量の判定動作を説明する。図５において、圧縮機３が稼働中であるか否かをチェックし（ステップＳ０）、稼働中でなければ稼働中になるまで待機する。圧縮機３が稼働中の場合には、圧力センサ２０より冷凍サイクル２の高圧側冷媒圧力Ｐｄ、第１冷媒温度センサ２１より冷凍サイクル２の高圧側冷媒温度Ｔｄ、第２空気温度センサ２５より室外熱交換器６を通過した空気温度Ｔａｍｂを検知する（ステップＳ３０）。次に、第２空気温度センサ２５の検知温度Ｔａｍｂより低圧側の冷媒圧力Ｐｓを推定する（ステップＳ３１）。次に、高圧側の冷媒圧力Ｐｄと推定した低圧側の冷媒圧力Ｐｓを基に、圧縮機３の吸入過熱度と断熱効率より許容冷媒吐出温度Ｔｄ’を算出する。例えば、圧縮機３の吸入過熱度３０ｄｅｇ、断熱効率８０％を規定し、その時の圧縮機３の吐出冷媒圧力Ｐｄに対する圧縮機３の吐出冷媒温度Ｔｄ’を算出する。空気温度Ｔａｍｂが１０ｄｅｇＣにおいて、吐出冷媒圧力Ｐｄが８ＭＰ時の場合は１２９ｄｅｇＣ、８．５ＭＰ時の場合は１３６ｄｅｇＣというように、空気温度Ｔａｍｂが５ｄｅｇＣにおいて、吐出冷媒圧力Ｐｄが８ＭＰ時の場合は１３８ｄｅｇＣ、８．５ＭＰ時の場合は１４５ｄｅｇＣというように例えば算出される。 Next, the operation for determining the amount of refrigerant in the heating mode will be described. In FIG. 5, it is checked whether or not the compressor 3 is in operation (step S0). When the compressor 3 is in operation, the high pressure side refrigerant pressure Pd of the refrigeration cycle 2 from the pressure sensor 20, the high pressure side refrigerant temperature Td of the refrigeration cycle 2 from the first refrigerant temperature sensor 21, and the outdoor from the second air temperature sensor 25. The air temperature Tamb that has passed through the heat exchanger 6 is detected (step S30). Next, the refrigerant pressure Ps on the lower pressure side than the detected temperature Tamb of the second air temperature sensor 25 is estimated (step S31). Next, the allowable refrigerant discharge temperature Td ′ is calculated from the suction superheat degree of the compressor 3 and the adiabatic efficiency based on the low-pressure side refrigerant pressure Ps estimated as the high-pressure side refrigerant pressure Pd. For example, the suction superheat degree 30 deg of the compressor 3 and the heat insulation efficiency 80% are defined, and the discharge refrigerant temperature Td ′ of the compressor 3 with respect to the discharge refrigerant pressure Pd of the compressor 3 at that time is calculated. When the air temperature Tamb is 10 degC and the discharge refrigerant pressure Pd is 8 MP, it is 129 degC. When the discharge refrigerant pressure Pd is 8.5 MP, it is 136 degC. When the air temperature Tamb is 5 degC and the discharge refrigerant pressure Pd is 8 MP, 138 degC. In the case of 8.5 MP, for example, 145 degC is calculated.

次に、圧縮機３の実際の吐出冷媒温度Ｔｄと算出した許容吐出冷媒温度Ｔｄ’とを比較し（ステップＳ１３）、Ｔｄ’よりＴｄが越えた値であれば、冷媒量が過少であると判定する（ステップＳ１４）。冷媒量が過少と判定した場合には、圧縮機３を停止すると共に報知手段３１によって冷媒量の過少を知らせるべく出力する。Ｔｄ’よりＴｄが越えない値であれば、冷媒量が過少でないと判定し、上述した動作を繰り返す。 Next, the actual discharge refrigerant temperature Td of the compressor 3 is compared with the calculated allowable discharge refrigerant temperature Td ′ (step S13), and if the value exceeds Td from Td ′, the refrigerant amount is too small. Determination is made (step S14). When it is determined that the refrigerant amount is too small, the compressor 3 is stopped and the notification means 31 outputs to notify that the refrigerant amount is insufficient. If Td does not exceed Td ', it is determined that the refrigerant amount is not too small, and the above-described operation is repeated.

以上説明したように、本実施の形態では、圧縮機３の吐出冷媒圧力を検知する圧力センサ２０と、圧縮機３の吐出冷媒温度を検知する第１冷媒温度センサ２１と、冷凍サイクル２の低圧側の冷媒圧力を認識する低圧側圧力認識手段３０ａとから得られる情報を基に冷媒量の過少を判定したので、封入冷媒量の過少判定を従来例のように外気温度に基づく圧力レベルによって判定するのではないため、高精度な圧力センサを用いる必要がないと共に、必要とする検知情報は車両用空気調和装置１に通常付設される検知手段を用いて得ることができる。従って、特別な部品を追加することなく低コストに封入冷媒量の過少を判定できる。 As described above, in the present embodiment, the pressure sensor 20 that detects the refrigerant discharge pressure of the compressor 3, the first refrigerant temperature sensor 21 that detects the refrigerant discharge temperature of the compressor 3, and the low pressure of the refrigeration cycle 2. Since the low refrigerant amount is determined based on the information obtained from the low pressure side pressure recognizing means 30a for recognizing the refrigerant pressure on the side, the under determination of the filled refrigerant amount is determined by the pressure level based on the outside air temperature as in the conventional example. Therefore, it is not necessary to use a high-precision pressure sensor, and necessary detection information can be obtained by using a detection unit that is normally attached to the vehicle air conditioner 1. Therefore, it is possible to determine whether the amount of the enclosed refrigerant is too low at a low cost without adding special parts.

（第１変形例）
図６及び図７は前記実施の形態の第１変形例を示し、図６は冷媒モード時における封入冷媒量の過少判定フローチャート、図７は圧縮機の稼働時の熱を受けた場合のモリエル線図と冷凍サイクルの挙動線図である。 (First modification)
6 and 7 show a first modification of the above embodiment, FIG. 6 is a flowchart for determining the amount of the enclosed refrigerant in the refrigerant mode, and FIG. 7 is a Mollier wire when receiving heat during operation of the compressor. It is a behavior line figure of a figure and a refrigerating cycle.

図６において、圧縮機３の稼働判別ステップ（ステップＳ０）の後に、圧縮機３の稼働開始から５分以内の間であるか否かの判別ステップ（ステップＳ４）が挿入されている。圧縮機３の稼働開始から５分以内の間でのみ封入冷媒量の過少判定を行う。他のステップは、前記実施の形態と同一であるため、重複説明を省略する。 In FIG. 6, after the operation determination step (step S0) of the compressor 3, a determination step (step S4) for determining whether it is within 5 minutes from the start of operation of the compressor 3 is inserted. Only within 5 minutes from the start of operation of the compressor 3, the amount of the enclosed refrigerant is determined to be insufficient. The other steps are the same as those in the above embodiment, and a duplicate description is omitted.

つまり、図７に示すように、圧縮機３が稼働されると、圧縮機３自体の温度が上昇し、内部の圧縮機構部で圧縮された吐出冷媒の温度（ａ点）であっても、圧縮機３より吐出されるまでに加温された温度（ｂ点）となる。そこで、圧縮機３が加熱される前に封入冷媒量の過少判定を行う。従って、この第１変形例によれば、圧縮機の稼働時の熱による悪影響を受けることなく、封入冷媒量の過少を正確に判定できる。 That is, as shown in FIG. 7, when the compressor 3 is operated, the temperature of the compressor 3 itself rises, and even if it is the temperature of the discharged refrigerant (point a) compressed by the internal compression mechanism, It becomes the temperature (point b) heated before being discharged from the compressor 3. Therefore, before the compressor 3 is heated, the amount of the enclosed refrigerant is determined to be too small. Therefore, according to the first modification, it is possible to accurately determine whether the amount of the enclosed refrigerant is insufficient without being adversely affected by heat during operation of the compressor.

尚、暖房モード時における封入冷媒量の過少判定も同様に、圧縮機３の起動開始から５分以内の間にのみ行うようにすれば、同様の効果が得られる。 It should be noted that the same effect can be obtained if the determination of the amount of the enclosed refrigerant in the heating mode is similarly performed only within 5 minutes from the start of the start of the compressor 3.

（第２変形例）
図８は前記実施の形態の第２変形例を係る、冷媒モード時における封入冷媒量の過少判定フローチャートである。 (Second modification)
FIG. 8 is a flowchart for determining whether the amount of the enclosed refrigerant is insufficient in the refrigerant mode according to the second modification of the embodiment.

図８において、第１変形例と同様に、圧縮機３の稼働判別ステップ（ステップＳ０）の後に、圧縮機３の稼働開始から５分以内の間であるか否かの判別ステップ（ステップＳ４）が挿入されている。その上、許容吐出冷媒温度Ｔｄ’の算出ステップ（ステップＳ１２）の後に、第１冷媒温度センサ２１が検知した検知吐出冷媒温度Ｔｄと圧縮機３のモータコイル温度Ｔｃｏｉｌとを比較するステップ（ステップＳ５）が挿入されている。第１冷媒温度センサ２１が検知した検知吐出冷媒温度Ｔｄより圧縮機３のモータコイル温度が低い場合にのみ、封入冷媒量の過少の判定を行う。他のステップは、前記実施の形態と同一であるため、重複説明を省略する。 In FIG. 8, similarly to the first modification, after the operation determining step (step S0) for the compressor 3, a determining step for determining whether it is within 5 minutes from the start of operation of the compressor 3 (step S4). Has been inserted. In addition, after the step of calculating the allowable discharge refrigerant temperature Td ′ (step S12), the detected discharge refrigerant temperature Td detected by the first refrigerant temperature sensor 21 and the motor coil temperature Tcoil of the compressor 3 are compared (step S5). ) Is inserted. Only when the motor coil temperature of the compressor 3 is lower than the detected discharge refrigerant temperature Td detected by the first refrigerant temperature sensor 21, it is determined whether the amount of the enclosed refrigerant is too small. The other steps are the same as those in the above embodiment, and a duplicate description is omitted.

つまり、圧縮機３が電動モータ内蔵の場合には、上記と同様の理由によって吐出冷媒がモータコイルの熱で加温される。そこで、モータコイルの熱で加温されない状況でのみ封入冷媒量の過少を判定する。これにより、モータコイルの熱による悪影響を受けることなく、封入冷媒量の過少を正確に判定できる。 That is, when the compressor 3 includes an electric motor, the discharged refrigerant is heated by the heat of the motor coil for the same reason as described above. Therefore, it is determined whether the amount of the enclosed refrigerant is too low only in a situation where the motor coil is not heated by the heat. Thereby, it is possible to accurately determine whether the amount of the enclosed refrigerant is insufficient without being adversely affected by the heat of the motor coil.

尚、暖房モード時における封入冷媒量の過少判定も同様に、第１冷媒温度センサ２１が検知した検知吐出冷媒温度Ｔｄより圧縮機３のモータコイル温度が低い場合にのみ行うようにすれば、同様の効果が得られる。 Similarly, the determination of whether the amount of the enclosed refrigerant in the heating mode is too low is similarly performed only when the motor coil temperature of the compressor 3 is lower than the detected discharge refrigerant temperature Td detected by the first refrigerant temperature sensor 21. The effect is obtained.

（第３変形例）
図９は前記実施の形態の第３変形例を係る、冷媒モード時における封入冷媒量の過少判定フローチャートである。 (Third Modification)
FIG. 9 is a flowchart for determining whether the amount of the enclosed refrigerant is insufficient in the refrigerant mode according to the third modification of the embodiment.

図９において、前記第２変形例と同様に、第１冷媒温度センサ２１が検知した検知吐出冷媒温度Ｔｄと圧縮機３のモータコイル温度Ｔｃｏｉｌとを比較するステップ（ステップＳ５）が挿入されている。そして、検知吐出冷媒温度Ｔｄより圧縮機３のモータコイル温度Ｔｃｏｉｌが低い場合には、補正値α＝ゼロとし（ステップＳ５１）、圧縮機３のモータコイル温度Ｔｃｏｉｌが検知吐出冷媒温度Ｔｄ以上であれば、補正値α＝（Ｔｃｏｉｌ−Ｔｄ’）／２とする（ステップＳ５２）。次のステップで許容吐出冷媒温度Ｔｄ’と上記補正値を加えた値と実際の検知吐出冷媒温度Ｔｄとを比較する（ステップＳ５３）。他のステップは、前記実施の形態と同一であるため、重複説明を省略する。 In FIG. 9, the step (step S5) for comparing the detected discharge refrigerant temperature Td detected by the first refrigerant temperature sensor 21 with the motor coil temperature Tcoil of the compressor 3 is inserted as in the second modification. . When the motor coil temperature Tcoil of the compressor 3 is lower than the detected discharge refrigerant temperature Td, the correction value α is set to zero (step S51), and the motor coil temperature Tcoil of the compressor 3 is equal to or higher than the detected discharge refrigerant temperature Td. For example, the correction value α = (Tcoil−Td ′) / 2 is set (step S52). In the next step, the allowable discharge refrigerant temperature Td ', the value obtained by adding the correction value, and the actual detected discharge refrigerant temperature Td are compared (step S53). The other steps are the same as those in the above embodiment, and a duplicate description is omitted.

この第３変形例では、許容吐出冷媒温度Ｔｄ’に圧縮機３のモータコイル温度を補償した温度値によって封入冷媒量の過少を判定するので、圧縮機３の稼働中であれば、封入冷媒量の過少判定の時期を制限されることなく、圧縮機３のモータコイルの熱による影響を受けない正確な判定ができる。 In this third modified example, since it is determined whether the amount of enclosed refrigerant is excessive or not based on a temperature value obtained by compensating the motor coil temperature of the compressor 3 with the allowable discharge refrigerant temperature Td ′, the amount of enclosed refrigerant is determined if the compressor 3 is in operation. Therefore, it is possible to make an accurate determination without being affected by the heat of the motor coil of the compressor 3 without being limited in the timing of the underdetermination.

尚、暖房モード時における封入冷媒量の過少判定も同様に、許容吐出冷媒温度Ｔｄ’に圧縮機３のモータコイル温度を補償した温度値によって封入冷媒量の過少判定を行うようにすれば、同様の効果が得られる。 Similarly, the determination of the amount of the enclosed refrigerant in the heating mode is similarly performed if the determination of the amount of the enclosed refrigerant is performed based on the temperature value obtained by compensating the motor coil temperature of the compressor 3 with the allowable discharge refrigerant temperature Td ′. The effect is obtained.

（第４変形例）
図１０は前記実施の形態の第４変形例を係る、冷媒モード時における封入冷媒量の過少判定フローチャートである。 (Fourth modification)
FIG. 10 is a flowchart for determining whether the amount of the enclosed refrigerant is insufficient in the refrigerant mode according to the fourth modification of the embodiment.

図１０において、許容吐出冷媒温度Ｔｄ’の算出ステップ（ステップＳ１２）の後に、圧縮機３の電力Ｐｃｏｍｐを検知するステップ（ステップＳ６）と、電力Ｐｃｏｍｐに応じた値β＝（Ｐｃｏｍｐ×（１−０．９））／１００を加算するステップ（ステップＳ６１）とが挿入されている。そして、許容吐出冷媒温度Ｔｄに圧縮機３のモータに印加されている電力による熱損失温度値βを補償した温度値（Ｔｄ’＋β）と、検知吐出冷媒温度Ｔｄとを比較する（ステップＳ６２）。他のステップは、前記実施の形態と同一であるため、重複説明を省略する。 In FIG. 10, after the step of calculating the allowable discharge refrigerant temperature Td ′ (step S12), a step of detecting the power Pcomp of the compressor 3 (step S6), and a value β = (Pcomp × (1− 0.9)) / 100 is added (step S61). Then, the detected discharge refrigerant temperature Td is compared with the temperature value (Td ′ + β) obtained by compensating the allowable discharge refrigerant temperature Td for the heat loss temperature value β due to the electric power applied to the motor of the compressor 3 (step S62). . The other steps are the same as those in the above embodiment, and a duplicate description is omitted.

つまり、圧縮機３が電動モータ内蔵の場合には、上記と同様の理由によって吐出冷媒がモータコイルの熱で加温される。そこで、モータコイルの熱で加温された温度に基づいて封入冷媒量の過少を判定する。 That is, when the compressor 3 includes an electric motor, the discharged refrigerant is heated by the heat of the motor coil for the same reason as described above. Therefore, it is determined whether the amount of the enclosed refrigerant is too small based on the temperature heated by the heat of the motor coil.

この第４変形例では、許容吐出冷媒温度Ｔｄ’に圧縮機３のモータに印加されている電力による熱損失温度値を補償した温度値によって封入冷媒量の過少を判定するので、圧縮機３の稼働中であれば、封入冷媒量の過少判定の時期を制限されることなく、圧縮機３のモータコイルの熱による影響を受けない正確な判定ができる。 In this fourth modified example, since the amount of the enclosed refrigerant is determined based on the temperature value obtained by compensating the allowable discharge refrigerant temperature Td ′ for the heat loss temperature value due to the electric power applied to the motor of the compressor 3, If it is in operation, it is possible to make an accurate determination without being affected by the heat of the motor coil of the compressor 3 without being limited in the timing of the determination of the amount of the refrigerant to be filled.

尚、暖房モード時の封入冷媒量の過少判定も同様に、第１冷媒温度センサ２１が検知した検知吐出冷媒温度Ｔｄより圧縮機３のモータコイル温度が低い場合にのみ行うようにすれば、同様の効果が得られる。 Similarly, if the amount of the enclosed refrigerant in the heating mode is determined to be too low, the determination is made only when the motor coil temperature of the compressor 3 is lower than the detected discharge refrigerant temperature Td detected by the first refrigerant temperature sensor 21. The effect is obtained.

（その他）
前記実施の形態等では、低圧側冷媒圧力認識手段３０ａは、室内熱交換器４を通過する空気が空調空気とされる冷房モードでは、室内熱交換器４を通過した空気温度より低圧側の冷媒圧力を推定するので、室内熱交換器４の出口側の過熱度（スーパーヒート）を検知するための第３空気温度センサ２６を利用して冷凍サイクル２の低圧側の圧力を推定する。従って、冷凍サイクル２の低圧側の圧力を認識するのに、冷凍サイクルの低圧側に圧力センサを付設する必要がないため、システムのシンプル化、コスト削減等になる。 (Other)
In the embodiment and the like, the low-pressure side refrigerant pressure recognition means 30a is a refrigerant having a pressure lower than the temperature of the air that has passed through the indoor heat exchanger 4 in the cooling mode in which the air that passes through the indoor heat exchanger 4 is conditioned air. Since the pressure is estimated, the pressure on the low-pressure side of the refrigeration cycle 2 is estimated using the third air temperature sensor 26 for detecting the degree of superheat (superheat) on the outlet side of the indoor heat exchanger 4. Therefore, in order to recognize the pressure on the low pressure side of the refrigeration cycle 2, there is no need to attach a pressure sensor on the low pressure side of the refrigeration cycle, which simplifies the system and reduces costs.

実施の形態等では、低圧側冷媒圧力認識手段３０ａは、室外熱交換器６を通過する空気が外気とされる暖房モードでは、室外熱交換器６が載置される周辺の空気温度より低圧側の冷媒圧力を推定する。従って、室外熱交換器６が設置される周辺の空気温度を検知するための第２空気温度センサ２５を利用して冷凍サイクル２の低圧側の圧力を推定する。従って、冷凍サイクル２の低圧側の圧力を認識するのに、冷凍サイクル２の冷圧側に圧力センサを付設する必要がないため、システムのシンプル化、コスト削減等になる。 In the embodiment and the like, the low-pressure side refrigerant pressure recognition means 30a is lower than the ambient air temperature on which the outdoor heat exchanger 6 is placed in the heating mode in which the air passing through the outdoor heat exchanger 6 is outside air. The refrigerant pressure is estimated. Therefore, the pressure on the low pressure side of the refrigeration cycle 2 is estimated using the second air temperature sensor 25 for detecting the temperature of the air around the outdoor heat exchanger 6. Therefore, it is not necessary to attach a pressure sensor to the cold pressure side of the refrigeration cycle 2 in order to recognize the pressure on the low pressure side of the refrigeration cycle 2, thereby simplifying the system and reducing costs.

尚、低圧側冷媒圧力認識手段３０ａは、冷凍サイクル２の低圧側の圧力を検知する圧力センサより構成しても良いことはもちろんである。 Of course, the low-pressure side refrigerant pressure recognition means 30a may be constituted by a pressure sensor that detects the pressure on the low-pressure side of the refrigeration cycle 2.

尚、前記実施の形態等では、車両用空気調和装置１は、冷房モードと暖房モードを選択的に使用できる構成であるが、冷房モードのみ、又は、暖房モードのみに使用できるものであっても本発明が適用できることはもちろんである。 In addition, in the said embodiment etc., although the air conditioning apparatus 1 for vehicles is the structure which can selectively use a cooling mode and a heating mode, even if it can be used only for a cooling mode or only a heating mode, Of course, the present invention is applicable.

尚、前記実施の形態等では、車両用空気調和装置１の冷凍サイクル２は、臨界点を超える炭酸ガスを冷媒としているが、本発明は臨界点を超えない冷媒ガスを冷媒とするものであっても同様に適用できるものである。 In the embodiment and the like, the refrigeration cycle 2 of the vehicle air conditioner 1 uses the carbon dioxide gas exceeding the critical point as the refrigerant, but the present invention uses the refrigerant gas not exceeding the critical point as the refrigerant. However, the same applies.

本発明の実施の形態を示し、車両用空気調和装置の構成図である。1 shows an embodiment of the present invention and is a configuration diagram of a vehicle air conditioner. FIG. 本発明の実施の形態を示し、本発明の制御に関わる部分の回路ブロック図である。FIG. 3 is a circuit block diagram of a portion related to the control of the present invention, showing the embodiment of the present invention. 本発明の実施の形態を示し、モリエル線図と冷凍サイクルの挙動線図である。The embodiment of the present invention is shown, and is a Mollier diagram and a behavior diagram of a refrigeration cycle. 本発明の実施の形態を示し、冷却モード時における封入冷媒量の過少判定フローチャートである。FIG. 5 is a flowchart for determining an insufficient amount of an enclosed refrigerant in a cooling mode according to an embodiment of the present invention. 本発明の実施の形態を示し、暖房モード時における封入冷媒量の過少判定フローチャートである。FIG. 6 is a flowchart for determining the amount of refrigerant enclosed in the heating mode during the heating mode according to the embodiment of the present invention. 第１変形例に係る、冷媒モード時における封入冷媒量の過少判定フローチャートである。It is an under determination flow chart of the amount of encapsulated refrigerant at the time of refrigerant mode concerning the 1st modification. 第１変形例に係る、圧縮機の稼働時の熱を受けた場合のモリエル線図と冷凍サイクルの挙動線図である。It is a Mollier diagram at the time of receiving the heat at the time of operation of a compressor concerning the 1st modification, and a behavior diagram of a refrigerating cycle. 第２変形例に係る、冷媒モード時における封入冷媒量の過少判定フローチャートである。It is an under determination flow chart of the amount of encapsulated refrigerant at the time of refrigerant mode concerning the 2nd modification. 第３変形例に係る、冷媒モード時における封入冷媒量の過少判定フローチャートである。It is an under determination flow chart of the amount of encapsulated refrigerant at the time of refrigerant mode concerning the 3rd modification. 第４変形例に係る、冷媒モード時における封入冷媒量の過少判定フローチャートである。It is an under determination flow chart of the amount of encapsulated refrigerant at the time of a refrigerant mode concerning the 4th modification.

Explanation of symbols

１車両用空気調和装置（空気調和装置）
２冷凍サイクル
３圧縮機
４室内熱交換器（蒸発器）
５室内放熱器（放熱器）
６室外熱交換器（放熱器、蒸発器）
８第１減圧器（減圧手段）
９第２減圧器（減圧手段）
２０圧力センサ（高圧側圧力検知手段）
２１第１冷媒温度センサ（吐出冷媒温度検知手段）
２５第２空気温度センサ
２６第３空気温度センサ
３０制御部
３０ａ低圧側冷媒圧力認識手段
３０ｂ冷媒量過少判定手段 1 Vehicle air conditioner (air conditioner)
2 Refrigeration cycle 3 Compressor 4 Indoor heat exchanger (evaporator)
5 Indoor radiator (heat radiator)
6 Outdoor heat exchanger (heat radiator, evaporator)
8 First decompressor (pressure reducing means)
9 Second decompressor (pressure reducing means)
20 Pressure sensor (high pressure side pressure detection means)
21 1st refrigerant | coolant temperature sensor (discharge refrigerant | coolant temperature detection means)
25 2nd air temperature sensor 26 3rd air temperature sensor 30 Control part 30a Low pressure side refrigerant pressure recognition means 30b Refrigerant amount under-determination means

Claims

A compressor (3) for compressing refrigerant, heat radiators (5), (6) for exchanging heat between the refrigerant compressed by the compressor (3) and air, and radiating heat to the refrigerant, and the radiator Heat exchange is performed between the decompression means (8), (9) for decompressing the refrigerant cooled in (5), (6), and the air decompressed by the decompression means (8), (9). An air conditioner (1) comprising a refrigeration cycle (2) having at least evaporators (4) and (6) for absorbing heat by a refrigerant,
High pressure side pressure detection means (20) for detecting the discharge refrigerant pressure of the compressor, discharge refrigerant temperature detection means (21) for detecting the discharge refrigerant temperature of the compressor (3), and the refrigeration cycle (2). Low pressure side pressure recognition means (30a) for recognizing low pressure side refrigerant pressure, low pressure side refrigerant pressure recognized by the low pressure side pressure recognition means (30a), and compression detected by the high pressure side pressure detection means (20) By determining the maximum allowable discharge refrigerant temperature from the discharge refrigerant pressure of the machine (3) and comparing the allowable discharge refrigerant temperature with the detected discharge refrigerant temperature detected by the discharge refrigerant temperature detection means (21). An air conditioner (1) comprising: a refrigerant quantity under-determination means (30b) for judging whether or not the amount of refrigerant enclosed in the refrigeration cycle (2) is too small.

An air conditioner (1) according to claim 1,
In the cooling mode in which the air passing through the evaporator (4) is conditioned air, the low-pressure side refrigerant pressure recognizing means (30a) sets the refrigerant pressure on the low-pressure side from the air temperature passing through the evaporator (4). An air conditioner (1) characterized by estimating.

An air conditioner (1) according to claim 1,
In the heating mode in which the air passing through the evaporator (6) is outside air, the low-pressure side refrigerant pressure recognizing means (30a) has a lower pressure side than the ambient air temperature on which the evaporator (6) is placed. An air conditioner (1) characterized by estimating a refrigerant pressure.

It is an air conditioning apparatus (1) in any one of Claims 1-3,
The air conditioner (1) characterized in that the refrigerant amount under-determination means (30b) determines whether the amount of encapsulated refrigerant is insufficient within a predetermined time from the start of operation of the compressor (3).

It is an air conditioning apparatus (1) in any one of Claims 1-4, Comprising:
When the motor coil temperature of the compressor (3) is lower than the detected discharged refrigerant temperature detected by the discharged refrigerant temperature detecting means (21), the refrigerant amount underdetermined determining means (30b) determines whether the enclosed refrigerant amount is too low. An air conditioner (1) characterized in that

It is an air conditioning apparatus (1) in any one of Claims 1-5, Comprising:
When the motor coil temperature of the compressor (3) is higher than the detected discharged refrigerant temperature detected by the discharged refrigerant temperature detecting means (21), the refrigerant amount under-determining means (30b) is compressed to the allowable discharged refrigerant temperature. An air conditioner (1) characterized in that the amount of enclosed refrigerant is determined to be low based on a temperature value compensated for the motor coil temperature of the machine (3).

It is an air conditioning apparatus (1) in any one of Claims 1-6, Comprising:
The refrigerant quantity under-determining means (30b) is characterized in that the quantity of the enclosed refrigerant quantity is judged based on a temperature value obtained by compensating an allowable discharge refrigerant temperature for a heat loss temperature value due to electric power applied to the motor of the compressor (3). An air conditioner (1) to perform.

A compressor (3) for compressing refrigerant, heat radiators (5), (6) for exchanging heat between the refrigerant compressed by the compressor (3) and air, and radiating heat to the refrigerant, and the radiator Heat exchange is performed between the decompression means (8), (9) for decompressing the refrigerant cooled in (5), (6), and the air decompressed by the decompression means (8), (9). A control method for an air conditioner (1) including a refrigeration cycle (2) having at least evaporators (4) and (6) for absorbing heat by a refrigerant,
High pressure side pressure detection means (20) for detecting the discharge refrigerant pressure of the compressor (3), discharge refrigerant temperature detection means (21) for detecting the discharge refrigerant temperature of the compressor (3), and the refrigeration cycle ( 2) low pressure side pressure recognition means (30a) for recognizing the low pressure side refrigerant pressure;
Allowable discharge refrigerant allowed to the maximum from the refrigerant pressure on the low pressure side recognized by the low pressure side pressure recognition means (30a) and the discharge refrigerant pressure of the compressor (3) detected by the high pressure side pressure detection means (20). Whether or not the amount of the enclosed refrigerant in the refrigeration cycle (2) is too small by determining the temperature and comparing the allowable discharge refrigerant temperature with the detected discharge refrigerant temperature detected by the discharge refrigerant temperature detection means (21). A method for controlling the air conditioner (1), comprising:

A control method for an air conditioner (1) according to claim 8,
In the cooling mode in which the air passing through the evaporator (4) is conditioned air, the low-pressure side refrigerant pressure recognizing means (30a) sets the refrigerant pressure on the low-pressure side from the air temperature passing through the evaporator (4). A control method for an air conditioner (1) characterized by estimating.

A control method for an air conditioner (1) according to claim 8,
In the heating mode in which the air passing through the evaporator (6) is outside air, the low-pressure side refrigerant pressure recognizing means (30a) has a lower pressure side than the ambient air temperature on which the evaporator (6) is placed. A control method for an air conditioner (1), wherein the refrigerant pressure is estimated.

It is a control method of the air harmony device (1) in any one of Claims 8-10,
The control method for the air conditioner (1), wherein the determination of whether the amount of the enclosed refrigerant is too small is made within a predetermined time from the start of operation of the compressor (3).

It is a control method of the air harmony device (1) in any one of Claims 8-11,
An air conditioner that determines whether the amount of enclosed refrigerant is too low when the motor coil temperature of the compressor (3) is lower than the detected discharged refrigerant temperature detected by the discharged refrigerant temperature detecting means (30b). The control method of 1).

It is a control method of the air conditioning apparatus (1) in any one of Claims 8-12,
When the motor coil temperature of the compressor (3) is higher than the detected discharge refrigerant temperature detected by the discharge refrigerant temperature detection means (30b), the motor coil temperature of the compressor (3) is compensated for the allowable discharge refrigerant temperature. A control method for an air conditioner (1), wherein the amount of the enclosed refrigerant is determined to be low based on a temperature value.

It is a control method of the air harmony device (1) in any one of Claims 8-13,
The control method of the air conditioner (1), wherein the amount of the enclosed refrigerant is determined based on a temperature value obtained by compensating an allowable discharge refrigerant temperature for a heat loss temperature value caused by electric power applied to the motor of the compressor (3).