JPH06100396B2 - Refrigerator protection device - Google Patents
Refrigerator protection deviceInfo
- Publication number
- JPH06100396B2 JPH06100396B2 JP29819887A JP29819887A JPH06100396B2 JP H06100396 B2 JPH06100396 B2 JP H06100396B2 JP 29819887 A JP29819887 A JP 29819887A JP 29819887 A JP29819887 A JP 29819887A JP H06100396 B2 JPH06100396 B2 JP H06100396B2
- Authority
- JP
- Japan
- Prior art keywords
- temperature
- compressor
- refrigerant
- capacity
- set value
- 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 - Lifetime
Links
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- Compression-Type Refrigeration Machines With Reversible Cycles (AREA)
Description
【発明の詳細な説明】 （産業上の利用分野） 本発明は、冷凍装置における圧縮機の潤滑不良に対して
圧縮機を保護するようにした冷凍装置の保護装置の改良
に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a refrigerating machine protection device for protecting a compressor against poor lubrication of the compressor in the refrigerating machine.
（従来の技術） 本出願人は、先に、例えば特願昭62-5675号等の明細書
及び図面において、一台の室外ユニットに対して複数台
の室内ユニットを並列に接続した，いわゆるマルチ形式
の冷凍装置に対し、室外ユニットに内蔵する圧縮機の容
量制御を、通常の如く室内ユニットの運転台数に応じて
は行わず、代りに冷媒の凝縮温度を予め固定設定した設
定値にするよう容量制御して、冷凍性能の向上を図るよ
うにしたものを提案している。(Prior Art) In the description and drawings of, for example, Japanese Patent Application No. 62-5675, the present applicant has previously referred to a so-called multi-unit in which a plurality of indoor units are connected in parallel to one outdoor unit. For the refrigeration system of the type, the capacity control of the compressor built into the outdoor unit is not performed as usual, depending on the number of operating indoor units, but instead the condensation temperature of the refrigerant is set to a preset fixed value. It is proposed that the capacity is controlled to improve the refrigeration performance.
（発明が解決しようとする問題点） ところで、上記の如き圧縮機の容量制御において、外気
温度が低い状況での運転時には、低外気温度に伴い冷媒
の蒸発温度が低下し、それに伴い冷媒の凝縮温度も設定
値未満に低下するため、この凝縮温度を設定値にまで上
昇させるべく、圧縮機の容量は上記の容量制御により増
大調整されることになる。(Problems to be Solved by the Invention) By the way, in the capacity control of the compressor as described above, when operating in a situation where the outside air temperature is low, the evaporation temperature of the refrigerant decreases with the low outside air temperature, and the condensation of the refrigerant accordingly occurs. Since the temperature also drops below the set value, the capacity of the compressor is increased and adjusted by the above capacity control in order to raise the condensing temperature to the set value.
しかるに、外気温度の低下が極端な場合には、冷媒の凝
縮温度は圧縮機の容量の増大制御に伴い上昇して設定値
に保持されるものの、冷媒の蒸発温度は更に低下して、
凝縮温度と蒸発温度との間の温度差が大きくなり、圧縮
比の大きな状態になる。このことに伴い圧縮機では体積
効率が低下して冷媒循環量が減少し、密閉型の圧縮機等
では、特に冷媒で圧縮機モータの冷却を行うものでは、
その吐出ガス温度が上昇すると共に、これに含まれる圧
縮機の潤滑油の油温も上昇する。また、上記の大きな圧
縮比により圧縮機の圧縮効率が低下して発熱量が増大
し、上記潤滑油の油温の上昇を顕著にする傾向となる。
その結果、この潤滑油による圧縮機の潤滑性能が低下し
て、圧縮機の磨耗や軸受け部分の焼付き，破損を招くこ
とがあり、圧縮機の信頼性が低下することになる。However, when the outside air temperature is extremely lowered, the condensing temperature of the refrigerant rises with the increase control of the capacity of the compressor and is held at the set value, but the evaporation temperature of the refrigerant further decreases,
The temperature difference between the condensation temperature and the evaporation temperature becomes large, and the compression ratio becomes large. Along with this, the volume efficiency of the compressor is reduced and the amount of refrigerant circulation is reduced, and in a hermetic compressor or the like, particularly in the case of cooling the compressor motor with a refrigerant,
As the discharge gas temperature rises, the oil temperature of the lubricating oil of the compressor contained therein also rises. Further, the compression efficiency of the compressor is reduced due to the above large compression ratio, the amount of heat generated is increased, and the increase in the oil temperature of the lubricating oil tends to be remarkable.
As a result, the lubricating performance of the compressor is deteriorated by this lubricating oil, which may cause wear of the compressor and seizure or damage of the bearing portion, resulting in deterioration of the reliability of the compressor.
本発明は斯かる点に鑑みてなされたものであり、その目
的は、マルチ形式の冷凍装置において冷媒の凝縮温度を
設定値に一定保持する場合、上記の如く圧縮機の潤滑性
能の低下を招くほどの外気温度の極端な低下時には、上
記凝縮温度を一定保持すべき設定値を適宜補正すること
により、冷媒の凝縮温度と蒸発温度との差を狭めて圧縮
比を小さくし、よって圧縮機での体積効率を高めて冷媒
循環量の増大を図ると共に、圧縮機での圧縮効率を良好
にして発熱量の減少を図り、最終的に潤滑油の油温の上
昇を有効に抑制して、圧縮機の潤滑性能を良好に保持
し、圧縮機の信頼性の向上を図ることにある。The present invention has been made in view of such a point, and an object thereof is to reduce the lubricating performance of the compressor as described above when the condensing temperature of the refrigerant is kept constant at a set value in a multi-type refrigeration system. When the outside air temperature is extremely low, by appropriately correcting the set value at which the condensing temperature should be kept constant, the difference between the condensing temperature and the evaporating temperature of the refrigerant is narrowed to reduce the compression ratio. In addition to increasing the volumetric efficiency of the refrigerant to increase the refrigerant circulation amount, improve the compression efficiency in the compressor to reduce the heat generation amount, and finally effectively suppress the rise in the oil temperature of the lubricating oil to achieve compression. This is to maintain good lubrication performance of the machine and improve the reliability of the compressor.
（問題点を解決するための手段） 上記の目的を達成するため、本発明の解決手段は、第１
図に示すように、複数段の容量段階に調整される圧縮機
（１）を有する室外ユニット（Ａ）に対して、複数台の
室内ユニット（Ｂ）〜（Ｆ）を並列に接続してなる冷媒
循環系統（Ｚ）を備えたマルチ形式の冷凍装置を前提と
する。そして、上記冷媒循環系統（Ｚ）における冷媒の
凝縮温度を検出する凝縮温度検出手段（50）と、該凝縮
温度検出手段（50）の出力を受け、冷媒の凝縮温度を予
め固定設定された設定値に保持するよう上記圧縮機
（１）を容量制御する容量制御手段（51）とを設けると
ともに、冷媒の蒸発温度を検出する蒸発温度検出手段
（52）と、該蒸発温度検出手段（52）の出力を受け、蒸
発温度が上記圧縮機（１）の潤滑油による潤滑不良を招
く状況に相当する下限温度値以下のとき、上記容量制御
手段（51）での凝縮温度の設定値を低く補正する設定値
補正手段（53）とを設ける構成としたものである。(Means for Solving Problems) In order to achieve the above object, the solving means of the present invention is
As shown in the figure, a plurality of indoor units (B) to (F) are connected in parallel to an outdoor unit (A) having a compressor (1) adjusted to a plurality of capacity stages. A multi-type refrigeration system provided with a refrigerant circulation system (Z) is assumed. Then, a condensing temperature detecting means (50) for detecting the condensing temperature of the refrigerant in the refrigerant circulation system (Z) and an output of the condensing temperature detecting means (50) are received, and the condensing temperature of the refrigerant is set to a fixed setting in advance. A capacity control means (51) for controlling the capacity of the compressor (1) so as to hold the value at a value is provided, and an evaporation temperature detection means (52) for detecting the evaporation temperature of the refrigerant, and an evaporation temperature detection means (52). When the evaporation temperature is equal to or lower than the lower limit temperature value corresponding to the situation in which the lubricating oil of the compressor (1) causes lubrication failure, the set value of the condensation temperature in the capacity control means (51) is corrected to be low. And a setting value correction means (53) for performing the setting.
（作用） 以上の構成により、本発明では、冷凍運転時には、冷媒
循環系統（Ｚ）における冷媒の凝縮温度が凝縮温度検出
手段（50）で検出され、この検出された冷媒の凝縮温度
を設定値に保持するよう圧縮機（１）の容量が容量制御
手段（51）で増減制御されて、具体的に凝縮温度が設定
値未満のときには圧縮機の容量は大きくなり、逆に凝縮
温度が設定値を越えるときには圧縮機の容量は小さくな
る。(Operation) With the above configuration, in the present invention, the condensation temperature of the refrigerant in the refrigerant circulation system (Z) is detected by the condensation temperature detecting means (50) during the refrigeration operation, and the detected condensation temperature of the refrigerant is set to the set value. The capacity of the compressor (1) is controlled to increase or decrease by the capacity control means (51) so that the capacity of the compressor becomes large when the condensing temperature is lower than the set value, and conversely the condensing temperature is set to the set value. When it exceeds, the capacity of the compressor becomes small.
而して、外気温度が極端に低い状況（圧縮機（１）の潤
滑油による潤滑不良を招く状況）では、冷媒循環系統
（Ｚ）における冷媒の蒸発温度が下がり、冷媒の凝縮温
度もそれに応じて設定値未満に下がる。そのため、圧縮
機の容量は、凝縮温度を上昇させるべく、容量制御手段
（51）で増大側に制御され、そのため、冷媒の凝縮温度
は上昇して設定値に保持される一方で、冷媒の蒸発温度
は更に低下して圧縮比が大きくなり、圧縮機（１）では
体積効率の低下に伴い冷媒循環量が減少する。その結
果、例えば密閉型で冷媒で圧縮機モータの冷却を行うも
のでは、吐出ガス温度の上昇と共に潤滑油の油温が上昇
するとともに、圧縮機での圧縮効率が低下して発熱量が
増大し、上記潤滑油の油温の上昇が顕著になる状況とな
る。Thus, in a situation where the outside air temperature is extremely low (a situation in which lubrication failure of the compressor (1) causes lubrication failure), the evaporation temperature of the refrigerant in the refrigerant circulation system (Z) decreases, and the condensation temperature of the refrigerant also changes accordingly. Lower than the set value. Therefore, the capacity of the compressor is controlled to the increasing side by the capacity control means (51) in order to increase the condensing temperature, so that the condensing temperature of the refrigerant rises and is maintained at the set value, while the evaporation of the refrigerant evaporates. The temperature further decreases and the compression ratio increases, and in the compressor (1), the refrigerant circulation amount decreases with the decrease in volume efficiency. As a result, for example, in a hermetically sealed type that cools the compressor motor with a refrigerant, the oil temperature of the lubricating oil rises as the discharge gas temperature rises, and the compression efficiency of the compressor decreases and the amount of heat generation increases. In this situation, the oil temperature of the lubricating oil is markedly increased.
しかし、その際には、上記容量制御手段（51）での凝縮
温度の設定値が設定値補正手段（53）により低く補正さ
れるので、冷媒の凝縮温度がこの低い設定値に保持され
て蒸発温度との差が縮まり、圧縮比が小さくなる。その
結果、圧縮機（１）での体積効率が良くなってその分、
冷媒循環量が増大すると共に、圧縮機での圧縮効率が向
上して発熱量が減少し、潤滑油の油温は低下することに
なる。よって、圧縮機の軸受け部の磨耗や焼付き，破損
が防止されて、圧縮機の信頼性が向上することになる。However, at that time, since the set value of the condensing temperature in the capacity control means (51) is corrected to a low value by the set value correction means (53), the condensing temperature of the refrigerant is kept at this low set value and vaporization is performed. The difference from the temperature decreases and the compression ratio decreases. As a result, the volume efficiency of the compressor (1) is improved, and
As the refrigerant circulation amount increases, the compression efficiency in the compressor improves, the heat generation amount decreases, and the oil temperature of the lubricating oil decreases. Therefore, wear, seizure, and damage of the bearing of the compressor are prevented, and the reliability of the compressor is improved.
（実施例） 以下、本発明の実施例を第２図以下の図面に基づいて説
明する。(Embodiment) An embodiment of the present invention will be described below with reference to the drawings starting from FIG.
第２図は本発明をマルチ型式の空気調和装置に適用した
実施例を示し、（Ａ）は室外ユニット、（Ｂ）〜（Ｆ）
は該室外ユニット（Ａ）に並列に接続された室内ユニッ
トである。上記室外ユニット（Ａ）には、圧縮機（１）
と、上記圧縮機（１）から吐出されるガス中の油を分離
する油分離器（４）と、暖房運転時には図中実線の如く
切換わり冷房運転時には図中破線の如く切換わる四路切
換弁（５）と、冷房運転時に凝縮器、暖房運転時に蒸発
器となる室外熱交換器（６）およびそのファン（6a）
と、過冷却コイル（７）と、冷房運転時には冷媒流量を
調節し、暖房運転時には冷媒の絞り作用を行う室外電動
膨張弁（８）と、液化した冷媒を貯蔵するレシーバ
（９）と、アキュムレータ（10）とが主要機器として内
蔵されていて、該各機器（１）〜（10）は各々冷媒の連
絡配管（11）を介して冷媒の流通可能に接続されてい
る。FIG. 2 shows an embodiment in which the present invention is applied to a multi-type air conditioner, (A) is an outdoor unit, and (B) to (F).
Is an indoor unit connected in parallel to the outdoor unit (A). The outdoor unit (A) includes a compressor (1)
And an oil separator (4) for separating the oil in the gas discharged from the compressor (1), and a four-way switching that switches as shown by the solid line in the drawing during heating operation and as shown by the broken line in the drawing during cooling operation. A valve (5), an outdoor heat exchanger (6) that serves as a condenser during cooling operation and an evaporator during heating operation, and its fan (6a)
A supercooling coil (7), an outdoor electric expansion valve (8) that adjusts the refrigerant flow rate during cooling operation, and performs a refrigerant throttling operation during heating operation, a receiver (9) that stores liquefied refrigerant, and an accumulator. (10) is built in as a main device, and each of the devices (1) to (10) is connected through a refrigerant communication pipe (11) so that the refrigerant can flow.
そして、上記圧縮機（１）には、該圧縮機（１）の運転
周波数（つまり容量段階）を複数段階（例えば５段階）
に可変に調整するインバータ（2a）が備えられていると
共に、パイロット圧の高低に応じて圧縮機（１）の容量
を、容量100％のフルロード状態と、容量50％のアンロ
ード状態との２段階に調節するアンロード機構（2b）
と、該アンロード機構（2b）のパイロット管（図示せ
ず）へのパイロット圧を圧縮機（１）の吐出管（11n）
側（高圧側）または吸入管（11q）側（低圧側）に切換
える電磁弁（2c）とが付設されており、該電磁弁（2c）
が高圧側に切換えられると、圧縮機（１）の運転容量が
100％のフルロード状態に切換られる一方、電磁弁（2
c）が低圧側に切換えられると、圧縮機（１）の運転容
量が50％のアンロード状態に切換られるように構成され
ている。The compressor (1) has a plurality of operating frequencies (that is, capacity stages) of the operating frequency of the compressor (1) (for example, 5 stages).
Is equipped with an inverter (2a) for variably adjusting the capacity of the compressor (1) according to the high or low of the pilot pressure between 100% capacity full load state and 50% capacity unload state. Unload mechanism (2b) that adjusts in two stages
And the pilot pressure to the pilot pipe (not shown) of the unload mechanism (2b) is applied to the discharge pipe (11n) of the compressor (1).
Side (high pressure side) or suction pipe (11q) side (low pressure side) and a solenoid valve (2c) for switching the solenoid valve (2c)
Is switched to the high pressure side, the operating capacity of the compressor (1)
The solenoid valve (2
When c) is switched to the low pressure side, the operating capacity of the compressor (1) is switched to an unload state of 50%.
また、上記室内ユニット（Ｂ）〜（Ｆ）は同一構成であ
り、各々その内部には、冷房運転時には蒸発器、暖房運
転時には凝縮器となる室内熱交換器（12）…及びその送
風ファン（12a）…と、液冷媒分岐管（11a）…に介設さ
れて冷媒流量を調節し、冷房運転時に冷媒の絞り作用を
行う室内電動膨張弁（13）…が備えられ、該各機器（1
2），（13）は手動閉鎖弁（17）を配した連絡配管（11
b）を介して室外ユニット（Ａ）に接続されて、冷媒を
室外ユニット（Ａ）と複数台（５台）の室内ユニット
（Ｂ）〜（Ｆ）に循環させる冷媒循環系統（Ｚ）が形成
されている。Further, the indoor units (B) to (F) have the same configuration, and inside thereof, an indoor heat exchanger (12), which serves as an evaporator during cooling operation and a condenser during heating operation, and its blower fan ( , And an indoor electric expansion valve (13), which is provided in the liquid refrigerant branch pipes (11a), adjusts the refrigerant flow rate, and performs a refrigerant throttling action during the cooling operation.
2) and (13) are connecting pipes (11) equipped with a manual shutoff valve (17).
A refrigerant circulation system (Z) that is connected to the outdoor unit (A) via b) and circulates the refrigerant to the outdoor unit (A) and a plurality of (five) indoor units (B) to (F). Has been done.
また、各室内ユニット（Ｂ）〜（Ｆ）内において、（TH
1）…は各室内温度を検出する室温センサ、（TH2）…お
よび（TH3）…は各々室内熱交換器（12）…の液側およ
びガス側配管の温度を検出する温度センサである。ま
た、室外ユニット（Ａ）において、（TH4）は圧縮機
（１）の吐出管の温度を検出する温度センサ、（TH5）
は暖房運転時に室外熱交換器（６）における冷媒の蒸発
温度を検出する蒸発温度検出手段（52）としての蒸発温
度センサ、（TH6）は圧縮機（１）の吸入ガス温度を検
出する吸入ガス温度センサ、（P1）は暖房運転時には吐
出ガスの圧力、冷房運転時には吸入ガスの圧力を検知す
る圧力センサである。而して、上記蒸発温度センサ（TH
5）で検出する蒸発温度は、外気温度に対して比例関係
にあり、外気温度の低下に応じて低下する特性を有す
る。In addition, in each indoor unit (B) ~ (F), (TH
1) ... are room temperature sensors that detect the room temperature, and (TH2) ... and (TH3) ... are temperature sensors that detect the temperature of the liquid side and gas side piping of the indoor heat exchangers (12). Further, in the outdoor unit (A), (TH4) is a temperature sensor that detects the temperature of the discharge pipe of the compressor (1), and (TH5)
Is an evaporation temperature sensor as the evaporation temperature detecting means (52) for detecting the evaporation temperature of the refrigerant in the outdoor heat exchanger (6) during heating operation, and (TH6) is the intake gas for detecting the intake gas temperature of the compressor (1). The temperature sensor (P1) is a pressure sensor that detects the pressure of the discharge gas during the heating operation and the pressure of the suction gas during the cooling operation. Therefore, the evaporation temperature sensor (TH
The evaporation temperature detected in 5) is proportional to the outside air temperature, and has the characteristic of decreasing as the outside air temperature decreases.
尚、第２図において上記各主要機器以外に補助用の諸機
器が設けられている。（1h）は油分離器（４）から圧縮
機（１）に潤滑油を戻す油戻し配管（11u）に介設さ
れ、返油量をコントロールするキャピラリーチューブ、
（21）は吐出管と吸入管とを接続する均圧ホットガスバ
イパス回路（11d）に介設され、デフロスト時等に開作
動するホットガス用電磁弁である。また、（11e）は暖
房過負荷制御用バイパス回路であって、該バイパス回路
（11e）には、補助コンデンサ（22）、第１逆止弁（2
3）、暖房運転時に室内熱交換器（12）（凝縮器）が低
負荷時のとき開作動する高圧制御弁（24）および第２逆
止弁（25）が順次直列に接続されており、その一部には
運転停止時に液封を防止するための液封防止バイパス回
路（11f）および（11f′）が第３逆止弁（27）およびキ
ャピラリーチューブ（CP3）を介して設けられている。
さらに、（11g）は上記暖房過負荷制御用バイパス回路
（11e）の液冷媒側配管と主配管の吸入ガス管との間を
接続し、冷暖房運転時に吸入ガスの過熱度を調節するた
めのリキッドインジェクションバイパス回路であって、
該リキッドインジェクションバイパス回路（11g）には
圧縮機（１）のオン・オフと連動して開閉するインジェ
クション用電磁弁（29）と、感温筒（TP1）により検出
される吸入ガスの過熱度に応じて開度調節される自動膨
張弁（30）とが介設されている。In FIG. 2, various auxiliary devices are provided in addition to the above-mentioned main devices. (1h) is a capillary tube that is provided in an oil return pipe (11u) that returns lubricating oil from the oil separator (4) to the compressor (1), and controls the amount of returned oil.
Reference numeral (21) is a hot gas solenoid valve that is provided in a pressure equalizing hot gas bypass circuit (11d) that connects the discharge pipe and the suction pipe and that opens when defrosting or the like. Reference numeral (11e) is a heating overload control bypass circuit, and the bypass circuit (11e) includes an auxiliary capacitor (22) and a first check valve (2).
3), the high-pressure control valve (24) and the second check valve (25), which open when the indoor heat exchanger (12) (condenser) is under a low load during heating operation, are sequentially connected in series, A liquid seal prevention bypass circuit (11f) and (11f ') for preventing liquid seal at the time of stop of operation is provided in a part thereof through a third check valve (27) and a capillary tube (CP3). .
Further, (11g) is a liquid for connecting the liquid refrigerant side pipe of the heating overload control bypass circuit (11e) and the intake gas pipe of the main pipe to adjust the degree of superheat of the intake gas during the heating and cooling operation. An injection bypass circuit,
The liquid injection bypass circuit (11g) has an injection solenoid valve (29) that opens and closes in conjunction with the on / off operation of the compressor (1) and the superheat of the intake gas detected by the temperature sensing tube (TP1). An automatic expansion valve (30) whose degree of opening is adjusted in accordance therewith is provided.
また、第２図中、（F1）〜（F6）は冷媒回路あるいは油
戻し管中に介設された液浄化用フィルタ、（HPS）は圧
縮機保護用の高圧圧力開閉器、（SP）はサービスポート
である。Further, in FIG. 2, (F1) to (F6) are liquid purification filters provided in the refrigerant circuit or the oil return pipe, (HPS) is a high pressure switch for protecting the compressor, and (SP) is It is a service port.
次に、上記圧縮機（１）の運転容量の制御を暖房運転時
を例に挙げて第３図の制御フローに基いて説明する。
尚、この容量制御は室外ユニット（Ａ）に接続した室外
制御装置（15）により行われる。Next, control of the operating capacity of the compressor (1) will be described based on the control flow of FIG. 3 by taking the heating operation as an example.
The capacity control is performed by the outdoor control device (15) connected to the outdoor unit (A).
第３図において、スタートして、ステップS1で圧力セン
サ（P1）により検出した吸入ガス圧力を相当飽和温度に
換算して得られる冷媒温度Tc、つまり冷媒循環系統
（Ｚ）における冷媒の凝縮温度を検出した後、ステップ
S2で蒸発温度センサ（TH5）からの蒸発温度Teを把握
し、この蒸発温度Teが、第４図に示す如く、圧縮機
（１）の最低容量段階（運転周波数＝40Hz）での潤滑油
による圧縮機（１）の潤滑不良を招く状況に相当する下
限温度値（例えば−10℃）以下のとき、つまり外気温度
TairではTair＝−５℃以下か否かを判別する。そして、
Tair＞−５℃のときには、潤滑性能の良好時と判断し
て、ステップS3で凝縮温度Tcを一定に保持すべき設定値
Tcsを所定値TO（例えば46℃）に固定設定する。また、T
air＜−５℃のときには、潤滑不良を招く状況時と判断
して、ステップS4で設定値Tcsを、上記第４図に示す如
く、蒸発温度Te（外気温度Tair）の低下に応じて低下す
る潤滑性能の限界線の傾きに近似した傾きＫと、その時
の蒸発温度Teとの積Ｋ・Teを上記設定値Tcs（＝46℃）
から減算した値に低く補正することとする。In FIG. 3, after starting, the refrigerant temperature Tc obtained by converting the intake gas pressure detected by the pressure sensor (P1) to the equivalent saturation temperature in step S 1 , that is, the condensation temperature of the refrigerant in the refrigerant circulation system (Z) After detecting the
The evaporation temperature Te from the evaporation temperature sensor (TH5) is grasped by S 2 , and this evaporation temperature Te is the lubricating oil at the lowest capacity stage (operating frequency = 40Hz) of the compressor (1) as shown in Fig. 4. When the temperature is lower than the lower limit temperature value (for example, -10 ° C) that corresponds to the situation that causes poor lubrication of the compressor (1) due to
In Tair, it is determined whether Tair = -5 ° C or lower. And
Tair> at -5 ° C., it is determined that the good when the lubricating performance, set values should retain condensation temperature Tc constant at Step S 3
Tcs is fixedly set to a predetermined value T O (for example, 46 ° C). Also, T
When air <−5 ° C., it is determined that the situation causes lubrication failure, and the set value Tcs is decreased in step S 4 according to the decrease in the evaporation temperature Te (outside air temperature Tair) as shown in FIG. 4 above. The product of the slope K, which approximates the slope of the lubrication performance limit line, and the evaporation temperature Te at that time, K · Te, is the set value Tcs (= 46 ° C).
The value subtracted from is corrected to a lower value.
しかる後、凝縮温度Tcを上記で設定した設定値Tcsに固
定保持するよう、圧縮機（１）の運転容量のフィードバ
ック制御としてPI制御（比例−積分制御）を行うことと
し、ステップS5で圧縮機（１）の目標容量L1を、上記凝
縮温度Tcと設定値Tcsとの偏差の，今回と前回の値ｅ
（ｔ）,e（ｔ−Δｔ）に基いて、凝縮温度Tcが設定値Tc
sになるよう下記式 L1=LO＋Kc｛ｅ（ｔ）−ｅ（ｔ−Δｔ） ＋（Δt/2Ti）（ｅ（ｔ）＋ｅ（ｔ−Δｔ）｝ LO；現在の運転容量 Kc;ゲイン（定数） Ti;積分時間 Δt;サンプリング時間 で演算して、冷媒の凝縮温度Tcが設定値Tcsを越えると
きには、圧縮機（１）の容量段階を低くする一方、逆に
凝縮温度Tcが設定値Tcs未満のときには、圧縮機（１）
の容量段階を高くすることとする。Thereafter, to the condensation temperature Tc is fixed and held at the set value Tcs set above, PI control as feedback control of the operating capacity of the compressor (1) - and by performing (proportional integral control), compressed at step S 5 The target capacity L 1 of the machine (1) is the value e of the deviation between the condensation temperature Tc and the set value Tcs, this time and the previous time.
Based on (t) and e (t-Δt), the condensing temperature Tc is the set value Tc.
The following equation L 1 = L O + Kc {e (t) −e (t−Δt) + (Δt / 2Ti) (e (t) + e (t−Δt)} L O ; current operating capacity Kc ; Gain (constant) Ti; Integration time Δt; Sampling time is calculated, and when the condensation temperature Tc of the refrigerant exceeds the set value Tcs, the capacity stage of the compressor (1) is lowered, while the condensation temperature Tc is When it is less than the set value Tcs, the compressor (1)
The capacity level of will be increased.
しかる後、ステップS6で予め設定された容量マップに基
いて上記目標容量L1に対応した圧縮機（１）の運転容量
を把握して、この運転容量になるよう、圧縮機（１）の
実際の運転容量をインバータ（2a）及びアンロード機構
（2b）で制御する。そして、ステップS7でサンプリング
時間Δｔの経過を待って以上の動作を繰返して、冷媒循
環系統（Ｚ）における冷媒の凝縮温度Tcを設定値Tcsに
保持するよう圧縮機（１）を容量制御するようにしてい
る。Then, in step S 6 , the operating capacity of the compressor (1) corresponding to the target capacity L 1 is grasped based on the capacity map set in advance, and the compressor (1) is adjusted so as to have this operating capacity. The actual operating capacity is controlled by the inverter (2a) and unload mechanism (2b). Then, by repeating the above operation after waiting for the sampling time Δt at step S 7, which compressor (1) capacity control to hold the condensing temperature Tc of the refrigerant in the refrigerant circulation system (Z) to the set value Tcs I am trying.
よって、上記第３図の制御フローにおいて、ステップS1
により、圧力センサ（P1）により検出した吸入ガス圧力
に基いて冷媒循環系統（Ｚ）における冷媒の凝縮温度Tc
を検出するようにした凝縮温度検出手段（50）を構成し
ていると共に、ステップS2、S3、S5〜S7により、上記凝縮
温度検出手段（50）の出力を受け、冷媒の凝縮温度を予
め固定設定された設定値Tcs（＝46℃）に保持するよう
上記圧縮機（１）を容量制御するようにした容量制御手
段（51）を構成している。Therefore, in the control flow of FIG. 3 above, step S 1
The refrigerant condensing temperature Tc in the refrigerant circulation system (Z) is based on the suction gas pressure detected by the pressure sensor (P1).
Together constitute the condensation temperature detection means (50) which is adapted to detect the, in step S 2, S 3, S 5 ~S 7, receives the output of the condensation temperature detection means (50), condensation of the refrigerant A capacity control means (51) is configured to control the capacity of the compressor (1) so that the temperature is maintained at a preset set value Tcs (= 46 ° C.).
また、ステップS2、S4により、上記蒸発温度センサ（TH
5）の出力を受け、蒸発温度Teが上記圧縮機（１）の潤
滑油による潤滑の不良を招く状況に相当する下限温度値
（−10℃）以下のとき、上記容量制御手段（51）の凝縮
温度の設定値Tcs（46℃）を、蒸発温度Teの低下に応じ
て低く補正するようにした設定値補正手段（53）を構成
している。Further, in steps S 2 and S 4 , the evaporation temperature sensor (TH
When the evaporating temperature Te is less than the lower limit temperature value (-10 ° C) corresponding to the situation of causing the lubrication failure of the compressor (1) due to the output of 5), the capacity control means (51) The set value correction means (53) is configured to correct the set value Tcs (46 ° C.) of the condensation temperature to be low according to the decrease in the evaporation temperature Te.
したがって、上記実施例においては、暖房運転時、蒸発
温度Teが下限温度値（−10℃）を越える通常のときに
は、冷媒の凝縮温度Tcを一定値に保持すべき設定値Tcs
が所定値TO（46℃）に設定され、この設定値Tcs（46
℃）に凝縮温度Tcを固定保持するようインバータ（2a）
及びアンロード機構（2b）が容量制御手段（51）で制御
されて、圧縮機（１）の容量が増減変化し、例えば凝縮
温度Tcが設定値Tcs（46℃）未満のときには、圧縮機
（１）の容量が増大して、冷媒の凝縮温度Tcが設定値Tc
s（46℃）に向かって上昇する一方、逆に凝縮温度Tcが
設定値Tcs（46℃）を越えるときには、圧縮機（１）の
容量が低下して、冷媒の凝縮温度Tcが設定値Tcs（46
℃）に向かって低下し、凝縮温度Tcは設定値Tcs（46
℃）に良好に固定保持される。Therefore, in the above-described embodiment, during the heating operation, when the evaporation temperature Te normally exceeds the lower limit temperature value (−10 ° C.), the refrigerant condensation temperature Tc should be set to a constant value Tcs.
Is set to a predetermined value T O (46 ° C), and this set value Tcs (46
Inverter (2a) to keep the condensing temperature Tc fixed at
And the unload mechanism (2b) is controlled by the capacity control means (51) to increase or decrease the capacity of the compressor (1). For example, when the condensing temperature Tc is less than the set value Tcs (46 ° C), the compressor ( The capacity of 1) increases, and the condensation temperature Tc of the refrigerant becomes the set value Tc.
When the condensing temperature Tc exceeds the set value Tcs (46 ° C) while increasing toward s (46 ° C), the capacity of the compressor (1) decreases and the condensing temperature Tc of the refrigerant becomes the set value Tcs. (46
℃), the condensation temperature Tc is set to the set value Tcs (46
It is well fixed and held at (° C).
而して、暖房運転時に、外気温度Tairが下限温度値（−
５℃）以下に極端に低下した低外気温度時には、冷媒の
蒸発温度Teも下限温度値（−10℃）以下に下がり、これ
に伴い凝縮温度Tcも設定値Tcs（46℃）未満に低下する
ため、通常の制御では、圧縮機（１）の容量は、上記容
量制御手段（51）の容量制御によって増大制御されて、
凝縮温度Tcは設定値Tcs（46℃）に保持されることにな
るが、この場合には、圧縮機（１）の容量の増大に伴い
冷媒の蒸発温度Teが更に下がって、凝縮温度Tcと蒸発温
度Teとの差が顕著になり、圧縮比が大きくなる。その結
果、圧縮機（１）の体積効率が低下して冷媒循環系統
（Ｚ）の冷媒循環量が減少し、特に圧縮機（１）が密閉
型で圧縮機モータの冷却を冷媒で行う形式のものでは、
圧縮機（１）からの吐出ガス温度が上昇すると共に、こ
れに含まれる圧縮機（１）の潤滑油の油温も顕著に上昇
する。また、上記大きな圧縮比により圧縮機（１）の圧
縮効率が低下して発熱量が増大し、上記潤滑油の油温の
上昇は著しくなり、圧縮機（１）の潤滑不良を招く状況
となる。Thus, during heating operation, the outside air temperature Tair is lower than the lower limit temperature value (-
When the outside temperature is extremely low (5 ° C) or lower, the evaporation temperature Te of the refrigerant also drops to the lower limit temperature value (-10 ° C) or lower, and the condensing temperature Tc also drops to the set value Tcs (46 ° C) or less. Therefore, in normal control, the capacity of the compressor (1) is increased and controlled by the capacity control of the capacity control means (51),
The condensing temperature Tc is maintained at the set value Tcs (46 ° C), but in this case, the evaporation temperature Te of the refrigerant further decreases as the capacity of the compressor (1) increases, and the condensing temperature Tc becomes The difference from the evaporation temperature Te becomes remarkable, and the compression ratio becomes large. As a result, the volumetric efficiency of the compressor (1) is reduced and the amount of refrigerant circulation in the refrigerant circulation system (Z) is reduced. In particular, the compressor (1) is of a hermetic type and the compressor motor is cooled by a refrigerant. By what
As the discharge gas temperature from the compressor (1) rises, the oil temperature of the lubricating oil of the compressor (1) contained therein also rises remarkably. Further, due to the large compression ratio, the compression efficiency of the compressor (1) is reduced, the amount of heat generated is increased, and the oil temperature of the lubricating oil is significantly increased, resulting in poor lubrication of the compressor (1). .
しかし、本発明では、凝縮温度Tcの設定値Tcs（46℃）
が設定値補正手段（53）により補正されて、第４図に示
す如く、圧縮機（１）の潤滑性能を良好に保持できる限
界線の傾きに応じて、蒸発温度の低下に対し上記の通常
値（46℃）よりも漸次低くなる値になるので、凝縮温度
Tcがこの低下補正後の設定値Tcsに容量制御手段（51）
で保持されると、この凝縮温度Tcと蒸発温度Teとの差が
縮まって、圧縮比が小さくなる。その結果、圧縮機
（１）の体積効率は良好に保持されて冷媒循環量はほぼ
通常通りに確保されると共に、圧縮機（１）の圧縮効率
が向上して発熱量が少なくなり、圧縮機（１）の潤滑油
の油温の上昇は有効に抑制されることになる。よって、
潤滑油による圧縮機（１）の潤滑性能を良好に維持し
て、圧縮機の磨耗や軸受け部分の焼付き，破損を有効に
防止することができ、圧縮機（１）の信頼性の向上を図
ることができる。However, in the present invention, the set value Tcs (46 ° C) of the condensation temperature Tc is set.
Is corrected by the set value correction means (53), and as shown in FIG. 4, the normal temperature is reduced in accordance with the inclination of the limit line at which the lubricating performance of the compressor (1) can be favorably maintained. Condensation temperature as it will be gradually lower than the value (46 ° C)
Tc is the set value Tcs after this deterioration correction. Capacity control means (51)
When held at, the difference between the condensation temperature Tc and the evaporation temperature Te is reduced and the compression ratio is reduced. As a result, the volume efficiency of the compressor (1) is kept good and the refrigerant circulation amount is secured almost as usual, and the compression efficiency of the compressor (1) is improved to reduce the heat generation amount. The increase in the oil temperature of the lubricating oil of (1) is effectively suppressed. Therefore,
The lubricating performance of the compressor (1) due to the lubricating oil can be maintained well, and it is possible to effectively prevent the wear of the compressor and the seizure and damage of the bearing portion, thus improving the reliability of the compressor (1). Can be planned.
尚、上記実施例では、圧縮機（１）の容量をインバータ
（2a）及びアンロード機構（2b）の双方で制御したが、
インバータ（2a）のみで容量制御する場合等にも同様に
適用できるのは勿論である。また、蒸発温度検出手段
（52）を蒸発温度センサ（TH5）で構成したが、その
他、外気温度を検出する外気温度センサ等で構成しても
よい。In the above embodiment, the capacity of the compressor (1) was controlled by both the inverter (2a) and the unload mechanism (2b).
Of course, the same can be applied to the case where the capacity is controlled only by the inverter (2a). Further, although the evaporation temperature detecting means (52) is composed of the evaporation temperature sensor (TH5), it may be composed of an outside air temperature sensor or the like for detecting the outside air temperature.
（発明の効果） 以上説明したように、本発明によれば、マルチ形式の冷
凍装置において、運転時に冷媒の凝縮温度を予め一定値
に固定設定した設定値に保持するよう圧縮機を容量制御
する場合、冷媒の蒸発温度の極端な低下時には、上記設
定値を低く補正して、圧縮機の容量の増大に伴う圧縮比
の増大を抑制したので、圧縮機での体積効率や圧縮機効
率を良好に維持して、冷媒循環量を通常通り確保すると
共に圧縮機での発熱量を少なくして、圧縮機の潤滑油の
油温の上昇を有効に抑制でき、圧縮機の潤滑性能を維持
して、圧縮機の信頼性の向上を図ることができる。(Effects of the Invention) As described above, according to the present invention, in the multi-type refrigeration system, the capacity of the compressor is controlled so that the condensing temperature of the refrigerant is maintained at a preset value which is fixed at a fixed value during operation. In this case, when the evaporation temperature of the refrigerant is extremely lowered, the above set value is corrected to a low value to suppress the increase of the compression ratio due to the increase of the capacity of the compressor, so that the volume efficiency and the compressor efficiency of the compressor are improved. By maintaining the refrigerant circulation amount as usual and reducing the calorific value in the compressor, it is possible to effectively suppress the rise of the oil temperature of the lubricating oil of the compressor and maintain the lubricating performance of the compressor. Therefore, the reliability of the compressor can be improved.
第１図は本発明の構成を示すブロック図である。第２図
ないし第４図は本発明の実施例を示し、第２図は空気調
和機に適用した冷媒配管系統図、第３図は室外制御装置
による容量制御を示すフローチヤート図、第４図は凝縮
温度の設定値の補正を示す説明図である。 （Ａ）……室外ユニット、（Ｂ）〜（Ｆ）……室内ユニ
ット、（１）……圧縮機、（2a）……インバータ、（2
b）……アンロード機構、（TH5）……蒸発温度センサ、
（Ｚ）……冷媒循環系統、（50）……凝縮温度検出手
段、（51）……容量制御手段、（52）……蒸発温度検出
手段、（53）……設定値補正手段。FIG. 1 is a block diagram showing the configuration of the present invention. 2 to 4 show an embodiment of the present invention, FIG. 2 is a refrigerant piping system diagram applied to an air conditioner, FIG. 3 is a flow chart showing capacity control by an outdoor control device, and FIG. FIG. 4 is an explanatory diagram showing correction of a set value of condensing temperature. (A) ... outdoor unit, (B) to (F) ... indoor unit, (1) ... compressor, (2a) ... inverter, (2
b) …… Unload mechanism, (TH5) …… Evaporation temperature sensor,
(Z) ... Refrigerant circulation system, (50) ... Condensing temperature detecting means, (51) ... Capacity controlling means, (52) ... Evaporating temperature detecting means, (53) ... Set value correcting means.
Claims (1)
（１）を有する室外ユニット（Ａ）に対して、複数台の
室内ユニット（Ｂ）〜（Ｆ）を並列に接続してなる冷媒
循環系統（Ｚ）を備えたマルチ形式の冷凍装置におい
て、上記冷媒循環系統（Ｚ）における冷媒の凝縮温度を
検出する凝縮温度検出手段（50）と、該凝縮温度検出手
段（50）の出力を受け、冷媒の凝縮温度を予め固定設定
された設定値に保持するよう上記圧縮機（１）を容量制
御する容量制御手段（51）とを備えるとともに、冷媒の
蒸発温度又はこれに相当する信号を検出する蒸発温度検
出手段（52）と、該蒸発温度検出手段（52）の出力を受
け、蒸発温度が上記圧縮機（１）の潤滑油による潤滑不
良を招く状況に相当する下限温度値以下のとき、上記容
量制御手段（51）での凝縮温度の設定値を低く補正する
設定値補正手段（53）とを備えたことを特徴とする冷凍
装置の保護装置。1. A refrigerant in which a plurality of indoor units (B) to (F) are connected in parallel to an outdoor unit (A) having a compressor (1) adjusted to a plurality of capacity stages. In a multi-type refrigeration system equipped with a circulation system (Z), a condensation temperature detection means (50) for detecting the condensation temperature of the refrigerant in the refrigerant circulation system (Z) and an output of the condensation temperature detection means (50) are provided. And a capacity control means (51) for controlling the capacity of the compressor (1) so as to maintain the condensing temperature of the refrigerant at a preset fixed value, and to supply the evaporation temperature of the refrigerant or a signal corresponding thereto. The evaporation temperature detecting means (52) for detecting and the output of the evaporation temperature detecting means (52) are received, and the evaporation temperature is equal to or lower than the lower limit temperature value corresponding to the situation in which the lubricating oil of the compressor (1) causes lubrication failure. At this time, the condensation temperature in the capacity control means (51) Protection device setting value correcting means for correcting the set value lower and (53) a refrigeration apparatus comprising the.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP29819887A JPH06100396B2 (en) | 1987-11-26 | 1987-11-26 | Refrigerator protection device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP29819887A JPH06100396B2 (en) | 1987-11-26 | 1987-11-26 | Refrigerator protection device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH01139966A JPH01139966A (en) | 1989-06-01 |
| JPH06100396B2 true JPH06100396B2 (en) | 1994-12-12 |
Family
ID=17856485
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP29819887A Expired - Lifetime JPH06100396B2 (en) | 1987-11-26 | 1987-11-26 | Refrigerator protection device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH06100396B2 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH10170085A (en) * | 1996-12-04 | 1998-06-26 | Toshiba Ave Corp | Air conditioner |
| JP4892954B2 (en) * | 2005-12-16 | 2012-03-07 | ダイキン工業株式会社 | Air conditioner |
-
1987
- 1987-11-26 JP JP29819887A patent/JPH06100396B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH01139966A (en) | 1989-06-01 |
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