JPH06123500A - Freezing apparatus - Google Patents

Abstract

PURPOSE:To improve the reliability of oiling for a compressor bearing where supercooling of freezer oil is prevented by simplifying or making unnecessary water side maintenance by controlling the flow rate of a fluid refrigerant which effects cooling action with an oil condenser with the aid of temperature of the freezer oil to a compressor. CONSTITUTION:A refrigerant is discharged as high temperature high pressure gas by a compressor 1, and is separated in an oil separator 2 into refrigerant gas and freezer oil. The refrigerant gas becomes a condensed fluid through a condenser 3 and is stored in a fluid receptor 1. A chief fluid in the refrigerant fluid becomes wet low pressure gas owing to the action of an expansion valve 5 and is evaporated in an evaporator 6 to cool an article to be cooled and thereafter absorbed into the compressor 1. In contrast, the freezer oil separated by the oil separator 2 is cooled through a refrigerant cooling type oil condensor 7 and is oiled to each bearing of the compressor 1. The fluid refrigerant is fed to a flow rate valve 8 in which the high pressure gas is changed to low temperature intermediate pressure wet gas and the flow rate thereof is adjusted to cool the freezer oil from the oil separator 2 in the refrigerant cooling type oil condenser 7, and is thereafter sucked into a casing of the compressor 1.

Description

【発明の詳細な説明】Detailed Description of the Invention

【０００１】[0001]

【産業上の利用分野】本発明は冷凍機，空調機の冷凍サ
イクルに係り、特に、冷凍機油を冷却する際に、適正な
油温度にする冷凍装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerating cycle for refrigerating machines and air conditioners, and more particularly to a refrigerating apparatus for cooling a refrigerating machine oil to an appropriate oil temperature.

【０００２】[0002]

【従来の技術】従来の装置は、冷凍vol.６３，N0.７３
１ 昭和６３年９月号５０頁に記載のように、冷凍サイ
クル中における油冷却器の油冷却方式は、冷却水循環に
よる水冷式油冷却器が主流であり、冷凍機の冷却運転，
除霜運転等の運転状態に拘らず、常に同じ冷却作用が行
われている。2. Description of the Related Art A conventional device is a refrigeration vol.63, N0.73.
1 As described in September 1988, p. 50, the oil cooling system of the oil cooler in the refrigeration cycle is mainly a water-cooled oil cooler by cooling water circulation, and the cooling operation of the refrigerator,
The same cooling action is always performed regardless of the operating state such as the defrosting operation.

【０００３】[0003]

【発明が解決しようとする課題】上記従来技術では、水
冷式油冷却器は水側の経時的な汚れによる熱交換効率の
低下を防ぐため、定期的に水質の点検，冷却管内面の汚
れ清掃等のメンテナンスを必要とするという欠点があ
る。In the above prior art, the water-cooled oil cooler regularly checks the water quality and cleans the inner surface of the cooling pipe to prevent the heat exchange efficiency from being deteriorated due to dirt on the water side. There is a drawback in that maintenance is required.

【０００４】また、冷凍機運転状態が変化し凝縮圧力が
低下して吐出ガス温度は低下し、これに伴い油冷却器に
送られる冷凍機油の温度も低下し、冷凍機油への冷却作
用が不要な状態でも冷却作用を続けるため、この状態は
圧縮機への給油温度のますますの低下を招き、ひいては
冷凍機油の粘度低下及び冷媒の溶け込み量増加による、
圧縮機軸受の潤滑不良を招くという点について考慮され
ていなかった。Further, the refrigerating machine operating condition changes, the condensing pressure decreases, the discharge gas temperature decreases, and the temperature of the refrigerating machine oil sent to the oil cooler also decreases, so that there is no need to cool the refrigerating machine oil. Since the cooling action continues even in such a state, this state causes the temperature of the oil supplied to the compressor to decrease further, which in turn reduces the viscosity of the refrigerating machine oil and increases the amount of the melted refrigerant.
No consideration was given to the fact that lubrication failure of the compressor bearing is caused.

【０００５】また、冷凍機が冷却運転からホットガス除
霜運転へ移行すると、凝縮圧力は冷却運転中と比較して
著しく低下する。このため、給油温度が下がることによ
り、吐出ガス温度がさらに低下し、除霜効率が低下して
除霜時間が長時間となる点についても考慮がなされてい
なかった。Further, when the refrigerator shifts from the cooling operation to the hot gas defrosting operation, the condensing pressure drops remarkably as compared with during the cooling operation. Therefore, it has not been taken into consideration that the discharge gas temperature further decreases due to the decrease in the oil supply temperature, the defrosting efficiency decreases, and the defrosting time becomes long.

【０００６】本発明の目的は、水側メンテナンスを簡略
化、または、不要化すること、冷凍機油の過冷却を防止
し圧縮機軸受の給油の信頼性を向上すること、及び、ホ
ットガス除霜運転での除霜時間の短縮を図ることにあ
る。The object of the present invention is to simplify or eliminate maintenance on the water side, prevent overcooling of refrigerating machine oil to improve reliability of oil supply to compressor bearings, and hot gas defrosting. The purpose is to reduce the defrosting time during operation.

【０００７】[0007]

【課題を解決するための手段】上記目的を達成するため
に、本発明は油冷却器での冷凍機油冷却用として液冷媒
を湿りガス状に変化させたものを使用する。また、圧縮
機への給油温度の過冷却を防ぐためには、油冷却器から
圧縮機へ接続されている油配管にサーミスタを取付け給
油温度を検出し、前述の液冷媒量もしくは湿りガス量を
演算装置と流量弁により連続制御する。In order to achieve the above object, the present invention uses a liquid refrigerant which has been changed to a wet gas state for cooling refrigerating machine oil in an oil cooler. To prevent overcooling of the oil supply temperature to the compressor, attach a thermistor to the oil pipe connected to the compressor from the oil cooler to detect the oil supply temperature and calculate the amount of liquid refrigerant or wet gas described above. Continuously controlled by the device and flow valve.

【０００８】[0008]

【作用】流量弁は演算装置からの信号により開度を調整
する。予め設定された圧縮機への給油温度目標値と、サ
ーミスタにより検出された運転中の給油温度を演算装置
により比較し、流量弁へ信号を送り開度を変化させ、油
冷却器で油冷却作用を行う湿りガス量を調整する。この
動作により、冷凍機の運転中に、常に、最適な給油温度
を維持することが可能である。The function of the flow valve is adjusted by the signal from the arithmetic unit. An arithmetic unit compares the preset oil supply temperature target value for the oil supply with the oil temperature during operation detected by the thermistor, sends a signal to the flow valve to change the opening, and causes the oil cooler to cool the oil. Adjust the amount of moist gas. By this operation, it is possible to always maintain the optimum oil supply temperature during the operation of the refrigerator.

【０００９】また、ホットガス除霜運転では演算装置に
除霜信号を入力して、給油温度目標値を冷却運転中より
高めに変化させる。これにより、冷却運転時よりも冷凍
機油の冷却作用を行う湿りガス量を減少させ、ホットガ
ス除霜運転における給油温度ならびに吐出ガス温度が低
下することを防止する。給油温度目標値を変化させて
も、１回のホットガス除霜時間は１０〜１５分と短時間
であり、凝縮圧力は低くなるため圧縮機の過熱に至るこ
とはない。In the hot gas defrosting operation, a defrosting signal is input to the arithmetic unit to change the oil supply temperature target value to a higher value than during the cooling operation. This reduces the amount of wet gas that cools the refrigerating machine oil more than during the cooling operation, and prevents the oil supply temperature and the discharge gas temperature from decreasing during the hot gas defrosting operation. Even if the oil supply temperature target value is changed, one hot gas defrosting time is as short as 10 to 15 minutes, and the condensation pressure becomes low, so that the compressor is not overheated.

【００１０】[0010]

【実施例】以下、本発明の一実施例を図１ないし図３に
より説明する。図１中の矢印は冷媒及び冷凍機油の流れ
方向を示す。圧縮機１で冷媒は高温高圧のガスとなって
吐出され、油分離器２内で冷媒ガスと冷凍機油に分離さ
れる。冷媒ガスは凝縮器３で凝縮液となり受液器４に溜
まる。この冷媒液の内の主液は膨張弁５の作用により、
低圧の湿りガスとなり、蒸発器６内で蒸発し被冷却物の
冷却作用を行った後、圧縮機１に吸入される。一方、油
分離器２で分離した冷凍機油は冷媒冷却式油冷却器７で
冷却され圧縮機１の各軸受へ給油される。受液器４から
は、蒸発器６で冷却作用を行う主液の液冷媒出口とは別
個に油冷却用液冷媒は取り出し口を設ける。本液冷媒は
流量弁８へ送られ、ここで高圧の液を低温で中間圧力の
湿りガスに変化させ流量を調整して、冷媒冷却式油冷却
器７内で油分離器２からの冷凍機油を冷却した後、圧縮
機１の中間圧力領域であるケーシング内に吸入される。
本発明の制御フローチャートを図２に示し、吐出ガス温
度に対する給油温度の変化を図３に示す。図２のフロー
チャートのように、運転中の圧縮機１への給油温度（Ｔ
ｏ）はサーミスタ９により演算装置１０に入力され、こ
こで予め設定された給油温度目標値（Ｔｏｃ）との比較
により、冷媒冷却式油冷却器７へ送られる湿りガス量を
制御する流量弁８の開度を変化させる。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. The arrows in FIG. 1 indicate the flow directions of the refrigerant and the refrigerating machine oil. The refrigerant is discharged as high-temperature and high-pressure gas in the compressor 1, and is separated into refrigerant gas and refrigerating machine oil in the oil separator 2. The refrigerant gas becomes a condensed liquid in the condenser 3 and accumulates in the liquid receiver 4. Due to the action of the expansion valve 5, the main liquid in this refrigerant liquid is
It becomes a low-pressure moist gas, evaporates in the evaporator 6, cools the object to be cooled, and is then sucked into the compressor 1. On the other hand, the refrigerating machine oil separated by the oil separator 2 is cooled by the refrigerant cooling type oil cooler 7 and supplied to each bearing of the compressor 1. From the liquid receiver 4, an outlet for the oil cooling liquid refrigerant is provided separately from the liquid refrigerant outlet for the main liquid that cools in the evaporator 6. The liquid refrigerant is sent to the flow valve 8, where the high-pressure liquid is changed to a wet gas at an intermediate pressure at low temperature to adjust the flow rate, and the refrigerating machine oil from the oil separator 2 is cooled in the refrigerant-cooled oil cooler 7. Is cooled and then sucked into the casing, which is the intermediate pressure region of the compressor 1.
The control flowchart of the present invention is shown in FIG. 2, and the change of the oil supply temperature with respect to the discharge gas temperature is shown in FIG. As shown in the flowchart of FIG. 2, the oil supply temperature (T
o) is input to the arithmetic unit 10 by the thermistor 9 and compared with a preset oil supply temperature target value (Toc) here to control the flow rate valve 8 for controlling the amount of wet gas sent to the refrigerant cooling type oil cooler 7. Change the opening of.

【００１１】流量弁開度が大きい時は弁を通過する湿り
ガス量の流量は大となり、開度が小さい時は流量も小さ
い状態となる。When the opening of the flow valve is large, the flow rate of the amount of wet gas passing through the valve is large, and when the opening is small, the flow rate is small.

【００１２】これにより、図３で線図（イ）の挙動とな
り、常に、予め設定され給油温度目標値（Ｔｏｃ）に収
束するための最適な湿りガス量が得られ、冷凍機油の過
冷却による給油温度低下を防ぐことができる。線図
（ロ）は従来の冷凍装置における挙動である。As a result, the behavior shown in the diagram (a) in FIG. 3 is obtained, and the optimum amount of moist gas for always converging to the preset oil supply temperature target value (Toc) is obtained, which is caused by the supercooling of the refrigerating machine oil. It is possible to prevent a decrease in refueling temperature. The diagram (b) shows the behavior in the conventional refrigeration system.

【００１３】図４はホットガス除霜運転中の給油温度目
標値（Ｔｏｃ）を、ホットガス除霜信号１１により、冷
却運転中より高めに変化させた場合の時間に対する温度
の変化を示し、この場合の制御フローチャートを図５に
示す。図５のフローチャートの動作により、給油温度は
図４で線図（ホ）の挙動となる。この時、ホットガス除
霜運転中の吐出ガス温度を低下させる作用も減少し、吐
出ガス温度は線図(ハ)の挙動となり、ホットガス除霜に
必要とする温度の維持が可能である。線図(ヘ)，（ニ）
は各々、給油温度目標値（Ｔｏｃ）を変化させない場合
の給油温度，吐出ガス温度の挙動である。FIG. 4 shows a change in temperature with time when the oil supply temperature target value (Toc) during the hot gas defrosting operation is changed by the hot gas defrosting signal 11 to be higher than during the cooling operation. A control flow chart in this case is shown in FIG. By the operation of the flowchart of FIG. 5, the refueling temperature has the behavior shown in the diagram (e) in FIG. At this time, the action of lowering the discharge gas temperature during the hot gas defrosting operation is also reduced, and the discharge gas temperature has the behavior shown in the diagram (c), and the temperature required for hot gas defrosting can be maintained. Diagram (f), (d)
Are behaviors of the oil supply temperature and the discharge gas temperature when the oil supply temperature target value (Toc) is not changed.

【００１４】[0014]

【発明の効果】本発明によれば、冷凍機油の冷却に冷却
水を使用しないため、経時的な熱交換の低下は無く、油
冷却器のメンテナンスは不要化できる。また、冷凍装置
の運転状態，据付環境の変化に応じた冷凍機油の冷却の
実施により、必要以上に過冷却されない温度変化の少な
い冷凍機油を圧縮機へ供給可能となり、圧縮機軸受への
給油の安定化，長寿命化を図ることができる。また、冷
凍機油の冷却に使用する液冷媒は、必要以上の使用を抑
制できるため、本来の被冷却物の冷却に使用する主液流
量を確保でき、蒸発器での能力低下を防ぐことができ
る。According to the present invention, since cooling water is not used for cooling refrigerating machine oil, heat exchange does not decrease over time, and maintenance of the oil cooler can be made unnecessary. Also, by cooling the refrigerating machine oil in response to changes in the operating condition of the refrigeration system and the installation environment, it becomes possible to supply refrigerating machine oil with less temperature change that is not overcooled more than necessary, to the compressor bearings. Stabilization and longer life can be achieved. Further, since the liquid refrigerant used for cooling the refrigerating machine oil can be restrained from being used more than necessary, the main liquid flow rate used for cooling the original object to be cooled can be secured, and the capacity deterioration in the evaporator can be prevented. .

【００１５】さらに、ホットガス除霜運転中における吐
出ガス温度の維持が可能となり、除霜時間の短縮が図
れ、被冷却物の品温上昇の抑制効果がある。Further, the discharge gas temperature can be maintained during the hot gas defrosting operation, the defrosting time can be shortened, and there is an effect of suppressing an increase in the temperature of the article to be cooled.

【図面の簡単な説明】[Brief description of drawings]

【図１】本発明の一実施例を示す冷凍サイクルの系統
図。FIG. 1 is a system diagram of a refrigeration cycle showing an embodiment of the present invention.

【図２】本発明の制御フローチャート。FIG. 2 is a control flowchart of the present invention.

【図３】吐出ガス温度に対する給油温度の変化を示す温
度特性図。FIG. 3 is a temperature characteristic diagram showing changes in oil supply temperature with respect to discharge gas temperature.

【図４】時間に対する温度変化を示す温度特性図。FIG. 4 is a temperature characteristic diagram showing a temperature change with time.

【図５】ホットガス除霜運転中に給油温度目標値を変化
させる場合の制御フローチャート。FIG. 5 is a control flowchart for changing the oil supply temperature target value during the hot gas defrosting operation.

【符号の説明】[Explanation of symbols]

１…圧縮機、２…油分離器、３…凝縮器、４…受液器、
５…膨張弁、６…蒸発器、７…冷媒冷却式油冷却器、８
…流量弁、９…サーミスタ、１０…演算装置、１１…ホ
ットガス除霜信号。1 ... Compressor, 2 ... Oil separator, 3 ... Condenser, 4 ... Liquid receiver,
5 ... Expansion valve, 6 ... Evaporator, 7 ... Refrigerant cooling type oil cooler, 8
... Flow valve, 9 ... Thermistor, 10 ... Computing device, 11 ... Hot gas defrosting signal.

フロントページの続き (72)発明者 鈴木 義文 静岡県清水市村松390番地 日立清水エン ジニアリング株式会社内Front page continuation (72) Inventor Yoshifumi Suzuki 390 Muramatsu, Shimizu City, Shizuoka Prefecture Hitachi Shimizu Engineering Co., Ltd.

Claims (1)

【特許請求の範囲】[Claims] 【請求項１】圧縮機，凝縮器，膨張弁，冷媒冷却式の油
冷却器，蒸発器等を配管接続して冷凍サイクルを形成
し、前記油冷却器で冷却作用を作う液冷媒の流量を、前
記圧縮機へ給油される冷凍機油の温度により制御するこ
とを特徴とする冷凍装置。1. A flow rate of a liquid refrigerant which forms a refrigerating cycle by connecting a compressor, a condenser, an expansion valve, an oil cooler of a refrigerant cooling type, an evaporator and the like to form a refrigerating cycle, and which makes a cooling action in the oil cooler. Is controlled by the temperature of the refrigerating machine oil supplied to the compressor.