JP3137362B2 - Automotive air conditioners - Google Patents
Automotive air conditionersInfo
- Publication number
- JP3137362B2 JP3137362B2 JP03157975A JP15797591A JP3137362B2 JP 3137362 B2 JP3137362 B2 JP 3137362B2 JP 03157975 A JP03157975 A JP 03157975A JP 15797591 A JP15797591 A JP 15797591A JP 3137362 B2 JP3137362 B2 JP 3137362B2
- Authority
- JP
- Japan
- Prior art keywords
- refrigerant
- expansion valve
- temperature
- valve
- evaporator
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B2500/00—Problems to be solved
- F25B2500/15—Hunting, i.e. oscillation of controlled refrigeration variables reaching undesirable values
Description
【０００１】[0001]
【産業上の利用分野】本発明は、熱交換媒体である冷媒
をＲ−１２からＲ−１３４ａに交換するとき温度膨脹弁
のみを交換すれば簡単に対処することができるようにし
た自動車用空気調和装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle air which can be easily handled by replacing only a temperature expansion valve when replacing a refrigerant as a heat exchange medium from R-12 to R-134a. It relates to a harmony device.
【０００２】[0002]
【従来の技術】自動車用空気調和装置は、熱交換媒体と
して一般にフロン系冷媒が使用されているが、最近で
は、このフロンガスによるオゾン層の破壊が地球規模の
環境問題として注目され、フロンガスの使用も禁止乃至
規制の方向にある。したがって、自動車用空気調和装置
においても、従来から使用されているフロン系冷媒の一
種であるＣＣｌ2 Ｆ2 （以下Ｒ−１２）という冷媒を廃
止し、オゾン層を破壊する虞の少ないＣＨ2 ＦＣＦ
2 （以下Ｒ−１３４ａ）という冷媒に変更する傾向にあ
る。2. Description of the Related Art Freon-based refrigerants are generally used as heat exchange media in air conditioners for automobiles. Recently, however, destruction of the ozone layer by this fluorocarbon gas has been attracting attention as a global environmental problem. Are also in the direction of ban or regulation. Therefore, even in an air conditioner for automobiles, a refrigerant called CCl 2 F 2 (hereinafter referred to as R-12), which is a kind of a CFC-based refrigerant, which has been conventionally used, is abolished, and CH 2 FCF which is less likely to destroy the ozone layer.
2 (hereinafter R-134a).
【０００３】[0003]
【発明が解決しようとする課題】ところが、Ｒ−１３４
ａという冷媒は、Ｒ−１２と種々の熱的特性が異なるこ
とから、Ｒ−１３４ａを用いて所望の冷房性能を得よう
とすれば、冷房サイクルを構成するコンプレッサ、コン
デンサ、温度膨脹弁、エバポレータという各構成要素を
全て新規なものに交換しなければならない。しかし、冷
房サイクルの全構成要素を新規なものとすることは、各
構成要素毎に設計変更しなければならないのみでなく、
生産設備あるいは組立て工程など生産ラインにおける機
械あるいは工程手順等も全て変更あるいは修正しなけれ
ばならず、製品である自動車用空気調和装置のコストを
増大させることになる。そこで、次善の策として、冷房
サイクルの各構成要素をＲ−１２のものを流用し、コン
プレッサの潤滑油あるいはシール剤のゴムの材質等を変
更する方法がある。この方法によれば、一応冷房運転を
行なうことができるものの、エバポレータの冷力の悪
化、低負荷時における温度膨脹弁のハンチング、コ
ンプレッサにおける消費動力の増大等という自動車用空
気調和装置における基本的性能に悪影響が生じることに
なり、余り好ましいものではなく、さらなる提案が希求
されているというのが実状である。However, R-134
Since the refrigerant a has different thermal characteristics from R-12, if a desired cooling performance is to be obtained by using R-134a, a compressor, a condenser, a temperature expansion valve, an evaporator constituting a cooling cycle Must be replaced with new ones. However, making all components of the cooling cycle new requires not only a design change for each component, but also
All machines or process procedures in a production line such as a production facility or an assembling process must be changed or modified, which increases the cost of a product air conditioner for a vehicle. Therefore, as a next best measure, there is a method of diverting the components of the cooling cycle of R-12 and changing the lubricating oil of the compressor or the rubber material of the sealant. According to this method, although the cooling operation can be performed for the time being, the basic performance in the air conditioner for automobiles such as the deterioration of the cooling power of the evaporator, the hunting of the temperature expansion valve at a low load, and the increase in the power consumption of the compressor, etc. In fact, it is not very favorable and further proposals are desired.
【０００４】さらに、詳述する。図４に示すように、一
般に冷房サイクルは、コンプレッサ２、コンデンサ３、
エバポレータ４を導管により連通し、さらに冷房サイク
ルを構成する要素として温度膨脹弁１も組込まれてい
る。この温度膨脹弁１は、ケーシングＣ内に弁体５が設
けられ、この弁体５による弁開口部６の開度は、図中の
エバポレータ４の出口部分の冷媒の温度を検知する感温
筒７内に封止された冷媒の圧力Ｆ1 と、エバポレータ出
口部分の冷媒の圧力が均圧管８によりダイアフラム９下
面を加圧するように導かれた圧力Ｆ2 と、弁体５を上方
に加圧するばねＳのばね力Ｆ3 とのバランスにより設定
され、これにより冷媒の流量制御を行なうとともに冷媒
を断熱膨脹させている。つまり、温度膨脹弁１は、エバ
ポレータ４の出口における冷媒の過熱度を制御するもの
である。ここに、エバポレータ出口の過熱度は、スーパ
ーヒート量とも言われ、エバポレータで蒸発した冷媒ガ
スを飽和温度以上に加熱し、コンプレッサへの帰還冷媒
が液状態で帰還しないように設定されるものである。し
たがって、例えば、エバポレータ４の出口における冷媒
の過熱度が過大となった時には、エバポレータ出口部分
の冷媒圧力に対する冷媒温度が上昇するので、前述のＦ
2 ，Ｆ3 に比してＦ1 が大となり、弁体５は開く方向に
働くことになる。しかし、弁体５が開けば、これにより
冷媒流量が増大する結果、過熱度の増大は抑制されるこ
とになる。Further details will be described. As shown in FIG. 4, a cooling cycle generally includes a compressor 2, a condenser 3,
The evaporator 4 is communicated by a conduit, and the temperature expansion valve 1 is also incorporated as an element constituting a cooling cycle. The temperature expansion valve 1 has a valve body 5 provided in a casing C. The degree of opening of the valve opening 6 by the valve body 5 is determined by detecting the temperature of the refrigerant at the outlet of the evaporator 4 in the figure. a pressure F 1 of the refrigerant sealed in the 7, the pressure F 2 led the underside diaphragm 9 to pressurize the pressure of the refrigerant in the evaporator outlet portion equalizing pipe 8, pressurizing the valve body 5 upward It is set by the balance between the spring force F 3 of the spring S, and refrigerant and adiabatically expanded with thereby controlling the flow rate of the refrigerant. That is, the temperature expansion valve 1 controls the degree of superheating of the refrigerant at the outlet of the evaporator 4. Here, the degree of superheat at the evaporator outlet is also called a superheat amount, and is set so that the refrigerant gas evaporated by the evaporator is heated to a temperature equal to or higher than the saturation temperature and the return refrigerant to the compressor does not return in a liquid state. . Therefore, for example, when the degree of superheat of the refrigerant at the outlet of the evaporator 4 becomes excessive, the refrigerant temperature with respect to the refrigerant pressure at the evaporator outlet part rises.
2, F 1 than the F 3 becomes large, the valve element 5 will act in the opening direction. However, when the valve body 5 is opened, the flow rate of the refrigerant increases, and as a result, the increase in the degree of superheat is suppressed.
【０００５】かかる冷房サイクルにおいて、各構成要素
を変更することなく、内部を流れる冷媒をＲ−１２から
Ｒ−１３４ａに変更した場合、このＲ−１３４ａは、図
５に示すように、低圧領域（エバポレータ４の出口の冷
媒圧力に相当し、通常、２〜３ｋｇ／ｃｍ2 ）では、Ｒ
−１２に比し蒸発温度が高くなるという特性を有してい
る。このような特性の下では、Ｒ−１３４ａの静止過熱
度は、「イ」となり、Ｒ−１２の静止過熱度である
「ロ」に比し少ないものとなる。In this cooling cycle, when the refrigerant flowing inside is changed from R-12 to R-134a without changing each component, as shown in FIG. It corresponds to the refrigerant pressure at the outlet of the evaporator 4, and usually, at 2-3 kg / cm 2 ), R
It has the characteristic that the evaporation temperature is higher than -12. Under such characteristics, the static superheat degree of R-134a is "A", which is smaller than the static superheat degree of "R-12" of R-12.
【０００６】ここに静止過熱度とは、設定圧力に対する
飽和温度から温度膨脹弁が開き始めるときまでの過熱度
をいう。一方、Ｒ−１３４ａの蒸発潜熱は、Ｒ−１２よ
りも大きく、このためＲ−１３４ａはＲ−１２よりも冷
房サイクル内を循環する場合の熱移送量が大きいという
特徴を有している。ここに、Ｒ−１３４ａの単位重量当
りの蒸発潜熱は、４７Kcal／kgであり、Ｒ−１２の単位
重量当りの蒸発潜熱は、３６Kcal／kgである。したがっ
て、Ｒ−１２を用いた場合とＲ−１３４ａを用いた場合
とを比較すれば、エバポレータ４の過熱度の変化に対応
する各冷媒の熱移送量は、図６に示すようになる。図６
より明らかなように、エバポレータの作動特性曲線と膨
脹弁の特性曲線が交差する動作点Ａ，Ｂにおける感温筒
７が検知する温度と、弁が開き始める点で感温筒７が検
知する温度との間の差温は、温度膨脹弁１が開弁した後
の過熱度となって表れるが、この過熱度は、Ｒ−１３４
ａが「ハ」となり、Ｒ−１２が「ニ」となる。この過熱
度は、Ｒ−１３４ａが単位流量当りの熱移送量が多いと
いう特性を有するため、Ｒ−１２より少なくなる。[0006] The term "superheat degree" means the degree of superheat from the saturation temperature with respect to the set pressure until the temperature expansion valve starts to open. On the other hand, the latent heat of vaporization of R-134a is larger than that of R-12, so that R-134a has a feature that the heat transfer amount when circulating in the cooling cycle is larger than that of R-12. Here, the latent heat of vaporization per unit weight of R-134a is 47 Kcal / kg, and the latent heat of vaporization per unit weight of R-12 is 36 Kcal / kg. Therefore, comparing the case where R-12 is used and the case where R-134a is used, the heat transfer amount of each refrigerant corresponding to the change in the degree of superheat of the evaporator 4 is as shown in FIG. FIG.
As is clear, the temperature detected by the temperature-sensitive cylinder 7 at the operating points A and B where the operating characteristic curve of the evaporator and the characteristic curve of the expansion valve intersect, and the temperature detected by the temperature-sensitive cylinder 7 at the point where the valve starts to open. Is expressed as a degree of superheat after the temperature expansion valve 1 is opened, and the degree of superheat is R-134.
a becomes "c" and R-12 becomes "d". This degree of superheat is smaller than that of R-12 because R-134a has the property that the amount of heat transfer per unit flow rate is large.
【０００７】このように各冷媒における静止過熱度と前
記過熱度のトータル的過熱度で両者を比較した場合、Ｒ
−１３４ａのものは「イ＋ハ」となり、Ｒ−１２のもの
は「ロ＋ニ」となる。このことは、膨脹弁を流用してＲ
−１３４ａを流した場合には、膨脹弁のバランス点での
過熱度が小さくなることを示している。過熱度が小さい
ということは、オイルに溶解した液状態の冷媒がコンプ
レッサに帰還し易くなり、エバポレータでの冷媒の蒸発
が不完全となり易いため、所望の冷房能力を得ることが
難しいことになる。そのうえコンプレッサの駆動動力が
液状態の冷媒を循環するために使われ、消費動力と冷房
能力との比である成績係数も悪化し、経済的にも問題の
ある状態となる。また、起動直後の冷房サイクルで、冷
媒の蒸発圧力が、その安定値に向って下降して行く過程
であるプルダウン時には、過熱度が小さいと、膨脹弁が
そのサイクルの能力以上の過大な量の冷媒を流すことに
なるため、蒸発圧力の低下が遅くなり、所望の冷房能力
を得るのに長時間を要すことになる。実験によれば、従
来の膨脹弁を流用してＲ−１３４ａを流した場合には、
Ｒ−１２を流す場合と比較し、約５〜１０％の冷力ダウ
ンが生じることが判明している。As described above, when both the static superheat degree and the total superheat degree of the superheat degree in each refrigerant are compared, R
Those of -134a are "I + H", and those of R-12 are "B + D". This is achieved by diverting the expansion valve to R
When -134a is supplied, it indicates that the degree of superheat at the balance point of the expansion valve is reduced. When the degree of superheat is small, the refrigerant in the liquid state dissolved in the oil easily returns to the compressor, and the evaporation of the refrigerant in the evaporator tends to be incomplete. Therefore, it is difficult to obtain a desired cooling capacity. In addition, the driving power of the compressor is used to circulate the refrigerant in the liquid state, and the coefficient of performance, which is the ratio between the power consumption and the cooling capacity, also deteriorates, resulting in an economically problematic state. Also, in the cooling cycle immediately after startup, when the evaporating pressure of the refrigerant is in the process of pulling down toward its stable value during pull-down, if the degree of superheat is small, the expansion valve may exceed the capacity of the cycle. Since the refrigerant flows, the decrease in the evaporation pressure is delayed, and it takes a long time to obtain a desired cooling capacity. According to experiments, when R-134a was flowed using a conventional expansion valve,
It has been found that the cooling power is reduced by about 5 to 10% as compared with the case of flowing R-12.
【０００８】温度膨脹弁は、前記図４に示すように、弁
体５のリフト量によって弁開口部６の開度を調節し、冷
媒流量を制御しているが、単位流量当りの熱移送量が大
きいＲ−１３４ａを使用すれば、弁体２のリフト量の変
化量に対する冷房能力の変化量（温度膨脹弁１が流した
冷媒がエバポレータ４において蒸発したときの吸熱量の
変化量）が大きくなる。これは、温度膨脹弁１のＦ1 と
Ｆ2 とＦ3 とのバランス点での弁体５のリフト量が小さ
い低負荷条件の下では顕著となり、弁体５が所定位置で
流量制御することが困難となり、弁体５が上下に変化す
る、いわゆるハンチングを起し易くなり、このハンチン
グを起せば、冷媒流量や過熱度の設定は一定せず、冷房
性能も変動することになる。As shown in FIG. 4, the temperature expansion valve controls the flow rate of the refrigerant by controlling the opening degree of the valve opening 6 according to the lift amount of the valve body 5, but the heat transfer amount per unit flow rate. If R-134a is large, the amount of change in cooling capacity with respect to the amount of lift of the valve body 2 (the amount of change in heat absorption when the refrigerant flowing through the temperature expansion valve 1 evaporates in the evaporator 4) is large. Become. This becomes remarkable under low load conditions the amount of lift of the valve body 5 at the balance point is small between F 1 and F 2 and F 3 of the temperature expansion valve 1, the valve body 5 is flow controlled at a predetermined position Hunting, which causes the valve element 5 to move up and down, is likely to occur. If this hunting occurs, the setting of the refrigerant flow rate and the degree of superheat will not be constant, and the cooling performance will also fluctuate.
【０００９】本発明は、上述した実状を考慮してなされ
たものであり、冷房サイクルの各構成要素をＲ−１２の
ものを流用しつつ、Ｒ−１２をＲ−１３４ａに置換する
ときに、温度膨脹弁を交換するのみで、エバポレータの
冷力の悪化を防止し、成績係数の悪化を抑制でき、低負
荷時でも温度膨脹弁がハンチングを起すこともない、生
産設備的にも製品コスト的にも優れた自動車用空気調和
装置を提供することを目的とする。The present invention has been made in consideration of the above-mentioned situation, and when replacing R-12 with R-134a while diverting components of the cooling cycle from R-12, By simply replacing the temperature expansion valve, it is possible to prevent the deterioration of the cooling power of the evaporator and to suppress the deterioration of the coefficient of performance. Even if the load is low, the temperature expansion valve does not cause hunting. It is another object of the present invention to provide an air conditioner for a vehicle that is excellent in the above.
【００１０】[0010]
【課題を解決するための手段】前記目的を達成するため
の本発明は、コンプレッサで圧縮された冷媒Ｒ−１２
を、コンデンサで凝縮し、温度膨脹弁で流量制御した後
に、エバポレータで蒸発させ前記コンプレッサに帰還さ
せるようにした冷房サイクルを有し、この冷房サイクル
中を流れる冷媒を前記Ｒ−１２からＲ−１３４ａに交換
してなる自動車用空気調和装置において、前記コンプレ
ッサ、コンデンサ、エバポレータはＲ−１２用のものを
流用し、前記温度膨張弁を、コンデンサからの冷媒が流
通する弁開口部の口径と、この弁開口部の開度を調節す
る弁体の大きさがＲ−１２のものよりも小さくし、同一
弁開度時の冷媒流量をＲ−１２の７４％程度としたもの
に置換するようにしたことを特徴とする自動車用空気調
和装置である。SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a refrigerant R-12 compressed by a compressor.
Is condensed by a condenser, the flow rate is controlled by a temperature expansion valve, and then the refrigerant is evaporated by an evaporator and returned to the compressor. The refrigerant flowing in the cooling cycle is discharged from the R-12 to R-134a. In the air conditioner for automobiles, the compressor, the condenser and the evaporator are diverted to those for R-12, and the temperature expansion valve is provided with a diameter of a valve opening through which the refrigerant from the condenser flows. The size of the valve body for adjusting the opening degree of the valve opening is made smaller than that of R-12, and the refrigerant flow rate at the same valve opening degree is replaced by about 74% of R-12. An air conditioner for a vehicle characterized by the above.
【００１１】前記温度膨張弁は、より好ましくは、エバ
ポレータから吐出される冷媒の温度を感知する感温筒内
に封止された活性炭の量、前記弁開口部を閉塞するよう
に付勢するばねのばね力を調節し、種々の条件下での過
熱度がＲ−１２と同等となるようにすることである。[0011] More preferably, the temperature expansion valve is an amount of activated carbon sealed in a temperature-sensitive cylinder for sensing the temperature of the refrigerant discharged from the evaporator, and a spring for urging the valve opening to close the valve opening. Is adjusted so that the degree of superheat under various conditions is equal to that of R-12.
【００１２】[0012]
【作用】このような本発明に係る自動車用空気調和装置
にあっては、熱交換媒体であるＲ−１２という冷媒から
Ｒ−１３４ａという異種の冷媒に交換するときに、温度
膨脹弁のみをＲ−１２用の温度膨脹弁とは、開口部の口
径、弁体の大きさが異なる温度膨脹弁とすれば、Ｒ−１
３４ａという異種の冷媒の流量を調節でき、Ｒ−１２の
場合と略同様の冷房運転を行なうことができる。つま
り、温度膨脹弁の開口部の口径及び弁体の大きさを変更
し、小さくすれば、同一弁開度時においては温度膨脹弁
から流出する冷媒量は少なくなり、蒸発潜熱が大きく熱
移送量の大きい特性を有するＲ−１３４ａであっても、
過熱度を適正値に制御することができる。この結果、エ
バポレータ内での液冷媒の蒸発が完全となり、冷房能力
が向上する上、プルダウン時の圧力低下速度の向上によ
り短時間で冷房能力が発揮されることになる。経済面で
も、コンプレッサの動力が未蒸発冷媒の循環に消費され
ることがなくなり、成績係数が向上することから良好に
なる。しかも、弁体のリフト量が小さい低負荷条件の下
で使用しても、弁体の流量制御は容易となり、弁体もハ
ンチングを起すことがない。また、前記温度膨張弁にお
いて、さらにエバポレータから吐出される冷媒の温度を
感知する感温筒内に封止された活性炭の量、前記弁開口
部を閉塞するように付勢するばねのばね力を調節すれ
ば、種々の条件下での過熱度に対する冷房能力をＲ−１
２と同等となるようにすることができ、これにより一層
Ｒ−１２の場合と略同様の冷房運転を行なうことができ
る。In the air conditioner for an automobile according to the present invention, when the refrigerant R-12, which is a heat exchange medium, is exchanged for a different refrigerant R-134a, only the temperature expansion valve is set to R. The temperature expansion valve for -12 is a temperature expansion valve having a different opening diameter and a different valve body size.
The flow rate of the different type of refrigerant 34a can be adjusted, and the cooling operation almost the same as that of R-12 can be performed. In other words, if the diameter of the opening of the temperature expansion valve and the size of the valve body are changed and made smaller, the amount of refrigerant flowing out of the temperature expansion valve at the same opening degree of the valve decreases, the latent heat of evaporation increases, and the heat transfer amount increases. R-134a having a large characteristic of
The degree of superheat can be controlled to an appropriate value. As a result, the evaporation of the liquid refrigerant in the evaporator becomes complete, the cooling capacity is improved, and the cooling capacity is exhibited in a short time due to the improvement of the pressure drop rate during pull-down. In terms of economy, the power of the compressor is not consumed in the circulation of the unevaporated refrigerant, and the coefficient of performance is improved. Moreover, even when the valve body is used under a low load condition where the lift amount of the valve body is small, the flow rate control of the valve body becomes easy, and the valve body does not hunt. Further, in the temperature expansion valve, the amount of activated carbon sealed in the temperature-sensitive cylinder for sensing the temperature of the refrigerant discharged from the evaporator, and the spring force of a spring for urging the valve opening to close the valve opening. If adjusted, the cooling capacity against superheat under various conditions is R-1
2 so that the same cooling operation as in the case of R-12 can be performed.
【００１３】[0013]
【実施例】以下、本発明に係る自動車用空気調和装置の
一実施例を図面に基づいて説明する。図１は、本発明の
一実施例に係る自動車用空気調和装置の冷房サイクルを
示す説明図、図２は、本実施例の温度膨脹弁の過熱度を
示す説明図、図３は、本実施例の温度膨脹弁の開弁特性
を示す説明図である。本実施例では、冷房サイクル中を
流されている冷媒Ｒ−１２を冷媒Ｒ−１３４ａに交換す
る場合、コンプレッサ１０、コンデンサ１１、エバポレ
ータ１３及び導管１４は、Ｒ−１２用のものを流用し、
温度膨脹弁１２のみを変更使用している。置換された冷
房サイクルであっても、冷媒の状態は、通常のものと同
様で、コンプレッサ１０により圧縮されたＲ−１３４ａ
がコンデンサ１１で凝縮され、温度膨脹弁１２で流量制
御された後に、エバポレータ１３で蒸発され前記コンプ
レッサ１０に帰還されるようになっている。BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of an air conditioner for a vehicle according to an embodiment of the present invention. FIG. 1 is an explanatory view showing a cooling cycle of an air conditioner for an automobile according to an embodiment of the present invention, FIG. 2 is an explanatory view showing a degree of superheat of a temperature expansion valve of the present embodiment, and FIG. It is explanatory drawing which shows the valve opening characteristic of the temperature expansion valve of an example. In the present embodiment, when replacing the refrigerant R-12 flowing in the cooling cycle with the refrigerant R-134a, the compressor 10, the condenser 11, the evaporator 13, and the conduit 14 divert the one for the R-12,
Only the temperature expansion valve 12 is changed and used. Even in the replaced cooling cycle, the state of the refrigerant is the same as the normal one, and the R-134a compressed by the compressor 10 is used.
Is condensed by a condenser 11, the flow rate is controlled by a temperature expansion valve 12, and then evaporated by an evaporator 13 and returned to the compressor 10.
【００１４】本実施例においては、冷媒交換後にＲ−１
３４ａを流しても、Ｒ−１２の場合と熱量的には略同一
条件で運転でき、略同一の冷房性能を発揮することがで
きるように温度膨脹弁１２の構成が変えられている。こ
の温度膨脹弁１２は、開口部２０の口径Ｄ、弁体２１で
あるボール弁の大きさＶが、Ｒ−１２用のものとは異な
るように設定されている。In this embodiment, after the refrigerant replacement, R-1
The configuration of the temperature expansion valve 12 is changed so that even if the flow 34a flows, the operation can be performed under substantially the same calorific conditions as in the case of R-12, and substantially the same cooling performance can be exhibited. This temperature expansion valve 12 is set so that the diameter D of the opening 20 and the size V of the ball valve 21 serving as the valve body 21 are different from those for the R-12.
【００１５】具体的には、Ｒ−１３４ａ用の温度膨脹弁
１２は、冷媒の流量がＲ−１２の略７４％となるよう
に、開口部２０の口径Ｄを略８０％とし、ボール弁の大
きさＶをＲ−１２の略７０％としている。ここに、「７
４％」としたのは、弁のリフト量に対する冷媒流量がＲ
−１２の約７４％になれば、弁リフト量に対する冷房能
力（温度膨脹弁１２が流した冷媒がエバポレータ１３に
おいて蒸発したときの吸熱量の変化量）がＲ−１２と同
一となることが実験的に判明したためであり、弁リフト
量に対する冷房能力が同一となれば、熱的に同一運転条
件となり、エバポレータ、コンデンサ、コンプレッサの
能力が冷媒がＲ−１３４ａとなっても略同一であること
が実験的に確認されたためである。More specifically, the temperature expansion valve 12 for the R-134a has a diameter D of the opening 20 of about 80% so that the flow rate of the refrigerant is about 74% of R-12, The size V is approximately 70% of R-12. Here, "7
4% "means that the refrigerant flow rate with respect to the valve lift amount is R
Experiments show that when the value becomes about 74% of -12, the cooling capacity with respect to the valve lift (the amount of change in the amount of heat absorbed when the refrigerant flowing through the temperature expansion valve 12 evaporates in the evaporator 13) becomes the same as R-12. If the cooling capacity with respect to the valve lift amount is the same, the same operating conditions will be obtained thermally, and the evaporator, condenser, and compressor capacity may be substantially the same even if the refrigerant becomes R-134a. This is because it was confirmed experimentally.
【００１６】前述したように温度膨脹弁１２の開口部２
０の口径Ｄを８０％程度、弁体２１の大きさＶを７０％
程度に小さくすれば、温度膨脹弁１２から流出される冷
媒量は、同一弁開度時のＲ−１２の約７４％程度にな
り、Ｒ−１３４ａであっても熱移送量は、低減する。こ
れによって、後述するばね２２のセット力及び感温筒２
３内に冷媒（通常Ｒ−１３）とともに封止された活性炭
２４の量が所定のものに調整されていれば、図２に示す
ように、静止過熱度「イ」も静止過熱度後の過熱度
「ハ」も大きくでき、温度膨脹弁１２のバランス点での
過熱度の幅「イ＋ハ」が大きくなり、Ｒ−１２のもの
「ロ＋ニ」と同程度になり、冷媒の制御性も向上し、プ
ルダウン時等のエバポレータ１３の冷力が悪化すること
もなく、所定の冷房性能を発揮することができる。As described above, the opening 2 of the temperature expansion valve 12
The diameter D of 0 is about 80%, and the size V of the valve body 21 is 70%.
If the temperature is reduced to a small extent, the amount of refrigerant flowing out of the temperature expansion valve 12 is about 74% of R-12 at the same valve opening, and the heat transfer amount is reduced even with R-134a. As a result, the setting force of the spring 22 and the temperature-sensitive
If the amount of the activated carbon 24 sealed together with the refrigerant (usually R-13) is adjusted to a predetermined value, the static superheat degree “A” is also the superheat after the static superheat degree, as shown in FIG. The degree “C” can be increased, and the width of superheat degree “I + H” at the balance point of the temperature expansion valve 12 increases, and it becomes almost the same as “R + D” of R-12, and the controllability of the refrigerant. The cooling performance of the evaporator 13 at the time of pull-down is not deteriorated, and a predetermined cooling performance can be exhibited.
【００１７】本実施例では、Ｒ−１３４ａ用の温度膨脹
弁１２がＲ−１２のものと同一の静止過熱度となるよう
に、ばね２２のセット力と感温筒２３内に封止された活
性炭２４の量を調整し、温度膨脹弁の制御性を向上させ
ている。前述したように静止過熱度は、ある圧力下の冷
媒の蒸発温度と膨脹弁の開弁温度との差であるから、冷
媒がＲ−１２からＲ−１３４ａに交換されたときに同等
の静止過熱度を得るには、図３のように開弁特性を、Ｒ
−１２とＲ−１３４ａの物性の相違に対応するように、
高温低圧側へシフトした上で、その傾きを少し大きくす
る必要がある。実験結果によれば、摂氏０度の開弁圧力
をＲ−１２用よりも０．２kg／cm2 、また摂氏１０度の
開弁圧力をＲ−１２用よりも０．１kg／cm2 低く設定す
れば、種々の条件下でＲ−１２と同一の過熱度が得られ
ることが分った。開弁特性の全体のシフトはばね力の調
整ねじを弛めることで、又傾きの増加は、感温筒内の活
性炭の量を増やすことで実現できる。In this embodiment, the temperature expansion valve 12 for the R-134a is sealed in the temperature-sensitive cylinder 23 and the set force of the spring 22 so that the temperature expansion valve 12 has the same degree of static superheat as that of the R-12. The amount of the activated carbon 24 is adjusted to improve the controllability of the temperature expansion valve. As described above, the degree of static superheat is the difference between the evaporation temperature of the refrigerant under a certain pressure and the opening temperature of the expansion valve. Therefore, when the refrigerant is exchanged from R-12 to R-134a, the equivalent static superheat is obtained. In order to obtain the degree, the valve opening characteristic is changed to R as shown in FIG.
To correspond to the difference in physical properties between R-12 and R-134a,
After shifting to the high temperature and low pressure side, it is necessary to slightly increase the inclination. According to the experimental results, also set 0.1 kg / cm 2 less than 0.2 kg / cm 2, also for R-12 the opening pressure of 10 ° C than for R-12 the opening pressure of 0 degrees Celsius Then, it was found that the same degree of superheating as R-12 was obtained under various conditions. The overall shift of the valve opening characteristic can be realized by loosening the adjusting screw for the spring force, and the inclination can be increased by increasing the amount of activated carbon in the temperature-sensitive cylinder.
【００１８】このようにばね２２のセット力と、感温筒
２３内に封止された活性炭２４の量とを調整すれば、エ
バポレータ１３の出口部分の冷媒の温度を感温筒２３が
検知し、内部に封止された不活性ガスの圧力が変化し、
所定の圧力Ｆ1 でダイアフラム２５の上面を加圧する。
一方、ダイアフラム２５の下面には、温度膨脹弁１２に
流入するＲ−１３４ａの圧力Ｆ2 が均圧管２６により導
入されるとともに、ばね圧調節ねじ（図示せず）により
ばね２２のセット力Ｆ3 が調節され、作動棒２７を介し
て伝達されている。By adjusting the setting force of the spring 22 and the amount of the activated carbon 24 sealed in the temperature-sensitive tube 23, the temperature-sensitive tube 23 detects the temperature of the refrigerant at the outlet of the evaporator 13. , The pressure of the inert gas sealed inside changes,
Pressurizing the upper surface of the diaphragm 25 at a predetermined pressure F 1.
On the other hand, on the lower surface of the diaphragm 25, with the pressure F 2 of R-134a flowing into the temperature expansion valve 12 is introduced by equalizing pipe 26, the set force F 3 of the spring 22 by the spring pressure adjusting screw (not shown) Is adjusted and transmitted via the actuation rod 27.
【００１９】したがって、Ｆ1 ，Ｆ2 ，Ｆ3 がバランス
した状態でＲ−１３４ａ用の温度膨脹弁１２の開度は決
定され、単位流量当りの熱移送量が大きいＲ−１３４ａ
でも所望の弁開度となるように調節される。これによっ
て、図２に示したようにエバポレータとの動作点での過
熱度をＲ−１２と同等に保つこととができ、冷媒置換に
よる過熱度の低下は防止できる。過熱度が適正になれ
ば、エバポレータでの冷媒の蒸発が完全となり、所望の
冷房能力を得ることができるうえ、液状態の冷媒がコン
プレッサに帰還しにくくなるので、消費動力も低減し、
成績係数も向上する。しかも、単位流量当りの熱移送量
が大きいＲ−１３４ａを弁体２１のリフト量が小さい低
負荷条件の下で使用しても、開口部２０を流通する冷媒
の量は、同一弁開度時のＲ−１２が流れる場合の略７４
％となるので、弁体２１の流量制御は容易となり、温度
膨脹弁１２はハンチングを起すことがない。Therefore, the opening of the temperature expansion valve 12 for the R-134a is determined in a state where F 1 , F 2 and F 3 are balanced, and the R-134a having a large heat transfer amount per unit flow rate is determined.
However, it is adjusted so as to have a desired valve opening. Thereby, as shown in FIG. 2, the degree of superheat at the operating point with the evaporator can be kept equal to that of R-12, and a decrease in the degree of superheat due to refrigerant replacement can be prevented. If the degree of superheat is proper, the evaporation of the refrigerant in the evaporator becomes complete, and the desired cooling capacity can be obtained.In addition, the refrigerant in the liquid state becomes difficult to return to the compressor, so that the power consumption is reduced.
The coefficient of performance also improves. In addition, even when R-134a having a large heat transfer amount per unit flow rate is used under a low load condition in which the lift amount of the valve body 21 is small, the amount of the refrigerant flowing through the opening 20 is the same when the valve opening degree is the same. About 74 when R-12 flows
%, The flow rate control of the valve body 21 becomes easy, and the temperature expansion valve 12 does not cause hunting.
【００２０】このように、冷房サイクル中の温度膨脹弁
１２のみを交換するのみで、Ｒ−１２と略同一運転条件
で、Ｒ−１３４ａを用いて冷房運転を行なうことができ
ることになる。したがって、Ｒ−１２の冷房サイクルに
おいて使用されていた構成要素の内、大部分を流用で
き、各構成要素の設計、生産設備あるいは組立て工程な
どの変更あるいは修正も不要となる。しかも、エバポレ
ータの冷力悪化、冷房サイクルとしての成績係数の悪
化、低負荷時における温度膨脹弁のハンチング等という
不具合もなく、性能的にも問題がないことから、冷媒の
交換を後顧の憂いなく容易に行なうことができる。As described above, by only replacing the temperature expansion valve 12 during the cooling cycle, the cooling operation can be performed using the R-134a under substantially the same operating conditions as the R-12. Therefore, most of the components used in the cooling cycle of R-12 can be diverted, and there is no need to change or modify the design of each component, the production equipment, or the assembling process. In addition, there is no problem such as deterioration of the cooling power of the evaporator, deterioration of the coefficient of performance as the cooling cycle, hunting of the temperature expansion valve at the time of low load, etc., and there is no problem in performance. It can be done easily.
【００２１】[0021]
【発明の効果】以上説明してきたように、本発明によれ
ば、冷媒をＲ−１２からＲ−１３４ａに交換するとき、
冷房サイクルの構成要素の大部分を流用し、温度膨脹弁
のみを弁開口部の口径、弁体の大きさを所定の大きさと
して交換するのみで、性能的にも生産設備的にもコスト
的にも問題のない冷房サイクルとすることができる。As described above, according to the present invention, when the refrigerant is exchanged from R-12 to R-134a,
Most of the components of the cooling cycle are diverted and only the temperature expansion valve is replaced with the specified size of the valve opening and the size of the valve body. Thus, a cooling cycle having no problem can be achieved.
【図１】は、本発明の一実施例の冷房サイクルを示す説
明図である。FIG. 1 is an explanatory diagram showing a cooling cycle according to one embodiment of the present invention.
【図２】は、本実施例の温度膨脹弁の過熱度を示す説明
図である。FIG. 2 is an explanatory diagram showing the degree of superheat of the temperature expansion valve of the present embodiment.
【図３】は、本実施例の温度膨脹弁の開弁特性を示す説
明図である。FIG. 3 is an explanatory diagram showing valve opening characteristics of the temperature expansion valve of the present embodiment.
【図４】は、従来の温度膨脹弁を用いた冷房サイクルを
示す説明図ある。FIG. 4 is an explanatory view showing a cooling cycle using a conventional temperature expansion valve.
【図５】は、従来の温度膨脹弁の特性を温度と圧力との
関係で示す線図である。FIG. 5 is a diagram showing characteristics of a conventional temperature expansion valve in relation to temperature and pressure.
【図６】は、同従来の温度膨脹弁の特性を温度と熱量と
の関係で示す線図である。FIG. 6 is a diagram showing characteristics of the conventional temperature expansion valve in relation to temperature and heat quantity.
１０…コンプレッサ、 １１…コンデン
サ、１２…温度膨脹弁、１３…エバポレータ、２０…弁
開口部、 ２１…弁体、２２…ば
ね、 ２３…感温筒、２４…活
性炭、 Ｄ…口径、Ｖ…弁体の大きさ。DESCRIPTION OF SYMBOLS 10 ... Compressor, 11 ... Condenser, 12 ... Temperature expansion valve, 13 ... Evaporator, 20 ... Valve opening, 21 ... Valve, 22 ... Spring, 23 ... Temperature sensing cylinder, 24 ... Activated carbon, D ... Diameter, V ... Valve Body size.
Claims (2)
１２を、コンデンサ(11)で凝縮し、温度膨脹弁(12)で流
量制御した後に、エバポレータ(13)で蒸発させ前記コン
プレッサ(10)に帰還させるようにした冷房サイクルを有
し、この冷房サイクル中を流れる冷媒を前記Ｒ−１２か
らＲ−１３４ａに交換してなる自動車用空気調和装置に
おいて、前記コンプレッサ(10)、コンデンサ(11)、エバ
ポレータ(13)はＲ−１２用のものを流用し、前記温度膨
張弁(12)を、コンデンサ(11)からの冷媒が流通する弁開
口部(20)の口径(D) と、この弁開口部(20)の開度を調節
する弁体(21)の大きさ(V) がＲ−１２のものよりも小さ
く、同一弁開度時の冷媒流量をＲ−１２の７４％程度と
したものに置換するようにしたことを特徴とする自動車
用空気調和装置。A refrigerant R-compressed by a compressor (10).
12 is condensed by a condenser (11), and after controlling the flow rate by a temperature expansion valve (12), has a cooling cycle in which it is evaporated by an evaporator (13) and returned to the compressor (10). In the air conditioner for automobiles, in which the refrigerant flowing therethrough is exchanged from R-12 to R-134a, the compressor (10), condenser (11), and evaporator (13) are diverted from those for R-12. The temperature expansion valve (12) is provided with a valve body (21) for adjusting the diameter (D) of the valve opening (20) through which the refrigerant flows from the condenser (11) and the opening degree of the valve opening (20). ) Is smaller than that of R-12, and the refrigerant flow rate at the same valve opening is replaced by about 74% of R-12. Harmony equipment.
3)から吐出される冷媒の温度を感知する感温筒(23)内に
封止された活性炭(24)の量、前記弁開口部(20)を閉塞す
るように付勢するばね(22)のばね力を調節し、種々の条
件下での過熱度がＲ−１２と同等となるようにしたこと
を特徴とする請求項２に記載の自動車用空気調和装置。The temperature expansion valve (12) is provided with an evaporator (1).
3) The amount of activated carbon (24) sealed in a temperature-sensitive cylinder (23) that senses the temperature of the refrigerant discharged from the spring, and a spring (22) for urging the valve opening (20) to close the valve opening (20). 3. The air conditioner according to claim 2, wherein the superheat degree under various conditions is adjusted to be equal to R-12 under various conditions.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP03157975A JP3137362B2 (en) | 1991-06-28 | 1991-06-28 | Automotive air conditioners |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP03157975A JP3137362B2 (en) | 1991-06-28 | 1991-06-28 | Automotive air conditioners |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH055578A JPH055578A (en) | 1993-01-14 |
| JP3137362B2 true JP3137362B2 (en) | 2001-02-19 |
Family
ID=15661519
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP03157975A Expired - Fee Related JP3137362B2 (en) | 1991-06-28 | 1991-06-28 | Automotive air conditioners |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3137362B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010032158A (en) * | 2008-07-30 | 2010-02-12 | Denso Corp | Refrigeration cycle device |
-
1991
- 1991-06-28 JP JP03157975A patent/JP3137362B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH055578A (en) | 1993-01-14 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5546757A (en) | Refrigeration system with electrically controlled expansion valve | |
| US6343486B1 (en) | Supercritical vapor compression cycle | |
| US5289692A (en) | Apparatus and method for mass flow control of a working fluid | |
| US5195331A (en) | Method of using a thermal expansion valve device, evaporator and flow control means assembly and refrigerating machine | |
| US5477701A (en) | Apparatus and method for mass flow control of a working fluid | |
| KR910700437A (en) | Trans Critical Incremental Compression Cycle Unit | |
| US5551249A (en) | Liquid chiller with bypass valves | |
| JP6405675B2 (en) | Cooling system | |
| EP0811813B1 (en) | Refrigeration system | |
| US20040107716A1 (en) | Method of operating a refrigeration cycle | |
| KR910004893Y1 (en) | Refrigeration circuit | |
| US2774220A (en) | Control for a refrigeration system | |
| US6038875A (en) | Vapor compression system | |
| CA2640635C (en) | Refrigerant fluid flow control device and method | |
| JP3137362B2 (en) | Automotive air conditioners | |
| WO2001057449A1 (en) | Constant temperature-humidity oven | |
| WO1996020378A1 (en) | Vapour compression system | |
| JP2010030325A (en) | Refrigeration cycle device with cool accumulator | |
| US3803864A (en) | Air conditioning control system | |
| JPH09133436A (en) | Temperature type expansion valve and air-conditioning device for vehicle using the valve | |
| JPH06272978A (en) | Air conditioner | |
| JPH1019389A (en) | Controlling equipment of degree of superheating of capillary tube | |
| JPH0526436Y2 (en) | ||
| JP2017150730A (en) | Refrigeration cycle device | |
| JP2003028516A (en) | Refrigerating cycle controller |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |