JPH0735425A - Refrigerating device - Google Patents

Refrigerating device

Info

Publication number
JPH0735425A
JPH0735425A JP5177937A JP17793793A JPH0735425A JP H0735425 A JPH0735425 A JP H0735425A JP 5177937 A JP5177937 A JP 5177937A JP 17793793 A JP17793793 A JP 17793793A JP H0735425 A JPH0735425 A JP H0735425A
Authority
JP
Japan
Prior art keywords
compressor
oil
speed compressor
amount
compressors
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.)
Withdrawn
Application number
JP5177937A
Other languages
Japanese (ja)
Inventor
Masashi Maeno
政司 前野
Toshihiko Yamanaka
敏彦 山中
Makoto Watabe
眞 渡部
Katsutoshi Kitagawa
勝敏 北川
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Mitsubishi Heavy Industries Ltd
Original Assignee
Mitsubishi Heavy Industries Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Mitsubishi Heavy Industries Ltd filed Critical Mitsubishi Heavy Industries Ltd
Priority to JP5177937A priority Critical patent/JPH0735425A/en
Publication of JPH0735425A publication Critical patent/JPH0735425A/en
Withdrawn legal-status Critical Current

Links

Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25BREFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2400/00General features or devices for refrigeration machines, plants or systems, combined heating and refrigeration systems or heat-pump systems, i.e. not limited to a particular subgroup of F25B
    • F25B2400/07Details of compressors or related parts
    • F25B2400/075Details of compressors or related parts with parallel compressors
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25BREFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2600/00Control issues
    • F25B2600/02Compressor control
    • F25B2600/025Compressor control by controlling speed
    • F25B2600/0253Compressor control by controlling speed with variable speed
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02BCLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B30/00Energy efficient heating, ventilation or air conditioning [HVAC]
    • Y02B30/70Efficient control or regulation technologies, e.g. for control of refrigerant flow, motor or heating

Landscapes

  • Compressors, Vaccum Pumps And Other Relevant Systems (AREA)

Abstract

PURPOSE:To permit the equal retention of oil in respective compressors by a method wherein suction pipelines for a plurality of constant-speed compressors are provided respectively with a resistance which surely reduces the internal pressure of a compressor at a side, in which a compressor is readily stopped upon light load under the condition that all of the compressors are operated. CONSTITUTION:A suction pipe is provided with a resistance 10b so that a point, whereat the internal pressure of a variable speed compressor coincides with the internal pressure of a constantspeed compressor 1b, becomes the amount of suction oil while a resistance 10c, which reduces the internal pressure of the constant-speed compressor 1c so as to be lower than the same of the constant-speed compressor 1b, is provided. As a result, the direction of discharging oil amount suction oil amount becomes the low side of the internal pressure and oil is moved from a high-pressure side compressor, in which the discharging amount of oil becomes smaller than the amount of suction oil. The constant speed compressor 1c is provided with the resistance 10c so that the internal pressure becomes lower than the same of the constant-speed compressor 1b whereby oil is moved from the constant-speed compressor 1b. Accordingly, oil is retained in respective compressors equally whereby trouble accompanied by the shortage of amount of oil can be prevented.

Description

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

【0001】[0001]

【産業上の利用分野】本発明は冷凍装置に関するもので
ある。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigeration system.

【0002】[0002]

【従来の技術】図1は複数の圧縮機を用いた従来の冷凍
装置の回路図である。図において、1aは可変速圧縮
機、1bおよび1cは定速圧縮機、2a,2b、2cは
前記各圧縮機の吐出管に設けられた油分離器、3は前記
吐出管の集合点に連る四方弁、4は同四方弁に連る室外
熱交換器、5は同熱交換器に連る逆止弁、6は同逆止弁
と並列に設けられている室外絞り、7a,7b,7c,
7dは前記逆止弁5と室外絞り6に連る可変絞り、8
a,8b,8c,8dは上記各可変絞りに連り、かつ前
記四方弁3に連る室内熱交換器、9は四方弁3に連りか
つ圧縮機1a,1b,1cの各吸入側に連るアキューム
レータ、11は各圧縮機を連通する均油管である。
2. Description of the Related Art FIG. 1 is a circuit diagram of a conventional refrigeration system using a plurality of compressors. In the figure, 1a is a variable speed compressor, 1b and 1c are constant speed compressors, 2a, 2b and 2c are oil separators provided in the discharge pipes of the compressors, and 3 is a connecting point of the discharge pipes. Four-way valve, 4 is an outdoor heat exchanger connected to the same four-way valve, 5 is a check valve connected to the same heat exchanger, 6 is an outdoor throttle provided in parallel with the check valve, 7a, 7b, 7c,
7d is a variable throttle connected to the check valve 5 and the outdoor throttle 6;
Reference numerals a, 8b, 8c, 8d are indoor heat exchangers connected to the variable throttles and the four-way valve 3, and 9 is connected to the four-way valve 3 and on each suction side of the compressors 1a, 1b, 1c. A continuous accumulator, 11 is an oil equalizing pipe that communicates with each compressor.

【0003】本装置において、圧縮機1a,1b,1c
から吐出された高温・高圧の冷媒ガスは、それぞれ油分
離器2a,2b,2cに入り、冷媒ガス中に含まれる油
分を分離した後集合して四方弁3に至る。冷房運転にお
いては、四方弁3より室外熱交換器4に至り、ここで放
熱し、凝縮・液化する。液化した冷媒は逆止弁5を経て
室内機に至る。各々の室内機には可変絞り7a,7b,
7c,7dが設けられており、ここで減圧され室内熱交
換器8a,8b,8c,8dに至る。この室内熱交換器
8a,8b,8c,8dにおいて、室内の空気と熱交換
を行い、冷媒は蒸発・気化する。気化した冷媒は、四方
弁3を経てアキュームレータ9に至る。アキュームレー
タを出た冷媒は、それぞれ油分離器2a,2b,2cに
おいて分離された油分と合流して圧縮機1a,1b,1
cに戻り冷凍サイクルを完了する。
In this apparatus, the compressors 1a, 1b, 1c
The high-temperature, high-pressure refrigerant gas discharged from each of them enters the oil separators 2a, 2b, 2c, separates the oil components contained in the refrigerant gas, and then gathers to reach the four-way valve 3. In the cooling operation, the four-way valve 3 reaches the outdoor heat exchanger 4, where heat is radiated and condensed / liquefied. The liquefied refrigerant reaches the indoor unit through the check valve 5. Each indoor unit has a variable aperture 7a, 7b,
7c, 7d are provided, and the pressure is reduced here to reach the indoor heat exchangers 8a, 8b, 8c, 8d. In the indoor heat exchangers 8a, 8b, 8c, 8d, heat is exchanged with the indoor air, and the refrigerant evaporates and vaporizes. The vaporized refrigerant reaches the accumulator 9 via the four-way valve 3. The refrigerant discharged from the accumulator merges with the oil components separated in the oil separators 2a, 2b, 2c, and the compressors 1a, 1b, 1
Returning to step c, the refrigeration cycle is completed.

【0004】暖房運転においても圧縮機部分は同一であ
り、四方弁3を経た高温・高圧ガスは各々の室内熱交換
器8a,8b,8c,8dに至り、ここで室内空気と熱
交換して放熱し、凝縮・液化する。液化した冷媒は可変
絞り7a,7b,7c,7dにおいて若干減圧され室外
絞り6に至る。ここで再度減圧され、室外熱交換器4に
至り、吸熱して蒸発・気化し、四方弁3、アキュームレ
ータ9を経て圧縮機1に戻る。圧縮機の運転台数は、室
内機の使用台数に応じて変更される。各圧縮機の油面レ
ベルを均一にするため、均油管11が設けられている。
Even in the heating operation, the compressor portion is the same, and the high temperature / high pressure gas passing through the four-way valve 3 reaches each indoor heat exchanger 8a, 8b, 8c, 8d, where heat is exchanged with the indoor air. Dissipates heat and condenses and liquefies. The liquefied refrigerant is slightly decompressed in the variable throttles 7a, 7b, 7c, 7d and reaches the outdoor throttle 6. Here, the pressure is reduced again, reaches the outdoor heat exchanger 4, absorbs heat, evaporates and vaporizes, and returns to the compressor 1 via the four-way valve 3 and the accumulator 9. The number of operating compressors is changed according to the number of indoor units used. An oil equalizing pipe 11 is provided to make the oil level of each compressor uniform.

【0005】[0005]

【発明が解決しようとする課題】図8の回路において
は、圧縮機1a,1b,1cより吐出される冷媒に含ま
れる油分は大部分各々の油分離器2a,2b,2cによ
り分離され、各圧縮機に接続される吸入配管を経て、そ
れぞれの圧縮機にもどるが、一部は冷媒ガスと共に冷凍
サイクル側にも出る。冷凍サイクル中に出た油分は、冷
媒と共に冷凍サイクル中を循環し、アキュームレータ9
に至る。アキュームレータを出た後は各圧縮機に分配さ
れる。この時の分配は可変速圧縮機が運転周波数によっ
て吐出油量が異なり、かつ各圧縮機から出た油分が冷媒
回路、アキュームレータ9で混合、平均化されるため、
各圧縮機へ戻る油分は必ずしも出た油分と一致しない。
In the circuit of FIG. 8, most of the oil contained in the refrigerant discharged from the compressors 1a, 1b, 1c is separated by the respective oil separators 2a, 2b, 2c, Although it returns to each compressor through the suction pipe connected to the compressor, a part of the refrigerant also goes out to the refrigeration cycle side together with the refrigerant gas. The oil content discharged during the refrigeration cycle circulates in the refrigeration cycle together with the refrigerant, and the accumulator 9
Leading to. After leaving the accumulator, it is distributed to each compressor. At this time, the variable speed compressor has a different discharge oil amount depending on the operating frequency, and the oil components discharged from each compressor are mixed and averaged by the refrigerant circuit and the accumulator 9,
The oil content returned to each compressor does not necessarily match the oil content output.

【0006】そのため冷凍サイクル中への吐出油分が多
い圧縮機は保有す油量が徐々に減少するので、均油管1
1を用いて保有油量が増加する圧縮機側から過剰な油を
移動させる。油の移動は均油管11で連結した圧縮機の
内部圧力によって高圧側から低圧側へ行われる。可変速
圧縮機の運転周波数や各圧縮機に接続される吸入管の形
状等によって必ずしも圧縮機内の油量が増加する方が高
圧側、油量が減少する方が低圧側となるとは限らない。
油量が減少する方が高圧側となった場合には、均油管1
1で連結された圧縮機から油は供給されず、減少しつづ
け、油分がなくなり、圧縮機故障の原因となる。
Therefore, the compressor has a large amount of oil discharged into the refrigeration cycle, and the amount of oil held in the compressor gradually decreases.
1 is used to move excess oil from the compressor side where the amount of retained oil increases. The movement of oil is performed from the high pressure side to the low pressure side by the internal pressure of the compressor connected by the oil equalizing pipe 11. Depending on the operating frequency of the variable speed compressor, the shape of the suction pipe connected to each compressor, and the like, the amount of oil in the compressor does not necessarily increase on the high-pressure side and the amount of oil decrease decreases on the low-pressure side.
If the amount of oil that decreases decreases to the high pressure side, the oil equalizing pipe 1
No oil is supplied from the compressor connected at 1, and the oil continues to decrease, and the oil content disappears, causing a compressor failure.

【0007】圧縮機内に吸入された油分は圧縮機内壁に
沿って流れおちるが、この油が流れおちる途中に圧縮機
内壁に設けられた均油管をつたわって直接高圧側から低
圧側へ移動することがあるので、油量が適性値以下に下
がる場合は、圧縮機故障の原因となる。
The oil component sucked into the compressor flows along the inner wall of the compressor, and while the oil flows down, the oil equalizing pipe provided on the inner wall of the compressor is connected to move directly from the high pressure side to the low pressure side. Therefore, if the amount of oil falls below the appropriate value, it will cause a compressor failure.

【0008】又、アキュームレータ9から圧縮機1a,
1b,1cに到る吸入管の分岐部で各圧縮機の冷媒循環
量の割合で油分を分岐することができず、いづれかの圧
縮機への油の戻りが少くなって油量が適性値以下となる
場合は、圧縮機故障の原因となる。
Further, from the accumulator 9 to the compressor 1a,
It is not possible to branch the oil at the ratio of the refrigerant circulation amount of each compressor at the branch portion of the suction pipe reaching 1b and 1c, and the amount of oil returned to either compressor is small, and the oil amount is below the appropriate value. In that case, it causes a compressor failure.

【0009】本発明は上記従来技術の欠点を解消し、各
圧縮機において油が均等に保持されるようにした冷凍装
置を提供しようとするものである。
The present invention aims to solve the above-mentioned drawbacks of the prior art and to provide a refrigerating apparatus in which oil is uniformly held in each compressor.

【0010】[0010]

【課題を解決するための手段】本発明は上記課題を解決
したものであって、1台の可変速圧縮機、同可変速圧縮
機に対して並列に接続された1台以上の定速圧縮機、凝
縮器、絞り、及び蒸発器を連結し、隣接した2台づつの
圧縮機を順次連結する均油管を設けた冷凍装置におい
て、下記の特徴を有するものである。
DISCLOSURE OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and is one variable speed compressor, and one or more constant speed compressors connected in parallel to the variable speed compressor. A refrigerating apparatus provided with an oil equalizing pipe that connects a compressor, a condenser, a throttle, and an evaporator and sequentially connects two adjacent compressors each has the following features.

【0011】(1)複数台の圧縮機を運転している時
に、可変速圧縮機とそれに連結された定速圧縮機の吐出
油量と吸入油量とが等しくなる可変速圧縮機の運転周波
数で、可変速圧縮機の内部圧力が、可変速圧縮機に均油
管で連結された定速圧縮機の内部圧力と等しくなるよう
な抵抗を吸入管路に設け、かつ、複数台接続された定速
圧縮機の吸入管路には全圧縮機運転時の軽負荷時に停止
し易い側の圧縮機の内部圧力が必ず低くなるような抵抗
を各々設けると共に、圧縮機内部圧力が可変速圧縮機と
均油管で連結した定速圧縮機から順次低くなる配列で各
圧縮機を均油管で連結したこと。
(1) When operating a plurality of compressors, the operating frequency of the variable speed compressor is such that the amount of discharge oil and the amount of intake oil of the variable speed compressor and the constant speed compressor connected thereto are equal. In this case, a resistance that equalizes the internal pressure of the variable speed compressor with the internal pressure of the constant speed compressor connected to the variable speed compressor by an oil equalizing pipe is provided in the suction pipe line, and the constant pressure connected to multiple units is fixed. The suction line of the high-speed compressor is equipped with a resistor that reduces the internal pressure of the compressor on the side that tends to stop when the load is light during full-compressor operation. Each compressor was connected with an oil equalizing pipe in an array in which the constant-speed compressors connected with the oil equalizing pipe were sequentially lowered.

【0012】(2)前記(1)項に記載の冷凍装置にお
いて、均油管が圧縮機の内壁から一定長さ以上内側へ突
出させて取り付けられていること。
(2) In the refrigerating apparatus according to the item (1), the oil equalizing pipe is attached so as to project inward from the inner wall of the compressor by a predetermined length or more.

【0013】(3)前記(1)項に記載の冷凍装置にお
いて、複数台の圧縮機の運転が一定時間経過した後、軽
負荷時運転停止側の圧縮機から順次停止した後、軽負荷
時運転継続側の圧縮機から順次一定時間運転を行う均油
運転制御手段を備えたこと。
(3) In the refrigerating apparatus according to the item (1), after a plurality of compressors have been operated for a certain period of time, the compressors on the operation stop side are sequentially stopped at light load, and then at light load. An oil-equalizing operation control means that sequentially operates for a fixed time from the compressor on the operation continuation side is provided.

【0014】[0014]

【作用】前記(1)項の発明に関して、可変速圧縮機お
よび可変速圧縮機と均油管で連結した定速圧縮機の複数
台運転時に、吐出油量>吸入油量となる側の圧縮機内部
圧力を低くし、吐出油量<吸入油量となる内部圧力の高
い側の圧縮機から油を移動することで油が減少しつづけ
ることを防止することができる。吐出油量=吸入油量と
なる可変速圧縮機の運転周波数より低い周波数では、定
則圧縮機側が、吐出油量>吸入油量で圧縮機内部圧力が
可変速圧縮機より低くなり、油の移動は可変速→定速と
なる。運転周波数が高い場合は油の移動は定速→可変速
となる。
According to the invention of the above item (1), when a plurality of variable speed compressors and a constant speed compressor connected to the variable speed compressor by an oil equalizing pipe are in operation, the discharge oil amount> the intake oil amount side compressor. It is possible to prevent the oil from continuing to decrease by lowering the internal pressure and moving the oil from the compressor on the high internal pressure side where discharge oil amount <intake oil amount. At a frequency lower than the operating frequency of the variable speed compressor where the amount of discharged oil = the amount of intake oil, the regular compressor side discharges the amount of oil> the amount of intake oil, the internal pressure of the compressor becomes lower than that of the variable speed compressor, and the oil moves. Is variable speed → constant speed. When the operating frequency is high, the oil movement is from constant speed to variable speed.

【0015】定速圧縮機を複数台接続し運転する場合
は、可変速圧縮機と均油管で連結した定速圧縮機に比
べ、次第に軽負荷時停止する側の定速圧縮機の内部圧力
を低くして行くことで、可変速圧縮機と油の移動を行
う。定速圧縮機と均油管で連結した定速圧縮機から順次
油を移動させ各圧縮機の油面確保を可能とする。
When a plurality of constant speed compressors are connected and operated, the internal pressure of the constant speed compressor, which gradually stops at a light load, is increased compared to the constant speed compressor connected to the variable speed compressor by an oil equalizing pipe. By lowering it, the variable speed compressor and oil are moved. The oil level of each compressor can be secured by sequentially moving the oil from the constant speed compressor connected to the constant speed compressor by an oil equalizing pipe.

【0016】前記(2)項の発明に関して、冷媒と油は
吸入管から圧縮機内部に入りシリンダに吸込まれるが油
分は圧縮機内壁に沿って流れ落ちる。均油管を圧縮機内
部へ一定値以上突っ込むことによって、圧縮機内壁に沿
って落ちる油が直接均油管に吸い込まれるのを防止し、
一定以上圧縮機内に溜った後、油が移動するようにして
圧縮機内の油面の確保を可能とする。
Regarding the invention of the above item (2), the refrigerant and the oil enter the inside of the compressor through the suction pipe and are sucked into the cylinder, but the oil component flows down along the inner wall of the compressor. By thrusting the oil equalizing pipe into the compressor by a certain amount or more, it is possible to prevent the oil falling along the inner wall of the compressor from being directly sucked into the oil equalizing pipe.
After the oil has accumulated in the compressor for a certain amount or more, the oil moves so that the oil level in the compressor can be secured.

【0017】前記(3)項の発明に関して、圧縮機を停
止することで圧縮機内部圧力は運転圧縮機に比べ高くな
るので均油管レベル以上の油は、停止側から運転側へ移
動することになる。各圧縮機の運転制御を行うことで油
量を平均化することを可能とする。
With respect to the invention of the above item (3), since the internal pressure of the compressor becomes higher than that of the operating compressor by stopping the compressor, oil above the oil equalizing pipe level moves from the stop side to the operating side. Become. By controlling the operation of each compressor, it is possible to average the amount of oil.

【0018】[0018]

【実施例】図1は本発明の第1実施例に係る複数圧縮機
を備えた冷凍装置の回路図である。図において、1aは
可変速圧縮機、1b,1cは同可変速圧縮機に対して並
列に接続されている定速圧縮機である。一般に定速圧縮
機は1台以上接続されるものである。10bおよび10
cはアキュームレータ9に連り途中で分岐して定速圧縮
機1b,1cに至る配管上に設けられた絞り、11a,
11bは隣接する2台づつの圧縮機を順次連結する均油
管である。上記以外の構成は従来技術(図8)と同じで
あるから説明を省略する。
1 is a circuit diagram of a refrigerating apparatus having a plurality of compressors according to a first embodiment of the present invention. In the figure, 1a is a variable speed compressor, and 1b and 1c are constant speed compressors connected in parallel to the variable speed compressor. Generally, one or more constant speed compressors are connected. 10b and 10
c is a throttle connected to the accumulator 9 and branched on the way to the constant speed compressors 1b and 1c, 11a,
Reference numeral 11b is an oil equalizing pipe that sequentially connects two adjacent compressors. Since the configuration other than the above is the same as that of the conventional technique (FIG. 8), description thereof will be omitted.

【0019】圧縮機1a,1b,1cから吐出された高
温・高圧の冷媒ガスは集合して四方弁3に至る。その後
アキュームレータ9に至るまでは、冷房運転、暖房運転
共、従来の技術で示した図8の場合と同じである。ここ
で各圧縮機から吐出される冷媒中の油分の量は可変速圧
縮機1aは運転周波数に対して、図2の通りとなる。す
なわち、可変速圧縮機においては、運転周波数が高い場
合は吐出油量が多く、低い場合は吐出油量は少なくな
る。一方、定速圧縮機は運転周波数が変化せず、吐出油
量は一定である。複数台圧縮機運転時には異なる油分の
冷媒が冷媒回路中で混合し、平均化した油分の冷媒がア
キュームレータ9から圧縮機1a,1b,1cにもど
り、吐出油量と吸入油量の関係は図3の通りとなる。可
変速圧縮機の運転周波数が低く、低吐出油量の場合は可
変速側が吐出量<吸入量、定速側が吐出量>吸入量とな
る。運転周波数が高い場合は可変速側が吐出量>吸入量
となり、定速側が吐出量<吸入量となり、ある点で圧縮
機1a,1bの吐出油量と吸入油量が一致する。
The high-temperature, high-pressure refrigerant gas discharged from the compressors 1a, 1b, 1c gathers and reaches the four-way valve 3. After that, up to the accumulator 9, both the cooling operation and the heating operation are the same as in the case of FIG. 8 shown in the related art. Here, the amount of oil in the refrigerant discharged from each compressor is as shown in FIG. 2 with respect to the operating frequency of the variable speed compressor 1a. That is, in the variable speed compressor, the amount of discharged oil is large when the operating frequency is high, and the amount of discharged oil is small when the operating frequency is low. On the other hand, the constant frequency compressor has a constant operating frequency and a constant discharge oil amount. When operating a plurality of compressors, different oil refrigerants are mixed in the refrigerant circuit, and the averaged oil refrigerant returns from the accumulator 9 to the compressors 1a, 1b, 1c, and the relationship between the discharge oil amount and the intake oil amount is shown in FIG. It becomes the street. When the operating frequency of the variable speed compressor is low and the amount of discharged oil is low, the variable speed side has a discharge amount <suction amount, and the constant speed side has a discharge amount> a suction amount. When the operating frequency is high, the variable speed side is the discharge amount> the suction amount, and the constant speed side is the discharge amount <the suction amount, and the discharge oil amount and the suction oil amount of the compressors 1a and 1b match at a certain point.

【0020】一方、圧縮機間の油の移動は、圧縮機内部
圧力差によって均油管を通して行われるが、圧縮機内部
圧力は可変速圧縮機を基準とすると図4のようになる。
ここで可変速圧縮機1aと定速圧縮機1bの内部圧力が
一致する点を吸入油量=吐出油量となる点(XHZ)とな
るように吸入管に抵抗10bを設け、かつ定速圧縮機1
cの内部圧力が定速圧縮機1bより低くなるような抵抗
10cを設ける。この結果、可変速圧縮機1aと定速圧
縮機1b間では可変速圧縮機の運転周波数によらず吐出
油量>吸入油量となる方が内部圧力が低圧側となり吐出
油量<吸入油量となる高圧側圧縮機より油が移動する。
定速圧縮機1cへは定速圧縮機1bより内部圧力が低く
なるように抵抗10cを設けてあるので定速圧縮機1b
より移動する。均油管11a,11bを図5の通り一定
値以上圧縮機内部に入れ込むことによって均油管レベル
位置になった時点で初めて油が他圧縮機へ移動するので
油が均油管位置以下の状態では移動はなくなる。
On the other hand, the movement of oil between the compressors is carried out through the oil equalizing pipe due to the pressure difference inside the compressor, and the internal pressure of the compressor is as shown in FIG. 4 on the basis of the variable speed compressor.
Here, a resistance 10b is provided in the suction pipe so that the point where the internal pressures of the variable speed compressor 1a and the constant speed compressor 1b coincide with each other becomes the point (X HZ ) where the suction oil amount = the discharge oil amount, and the constant speed is set. Compressor 1
A resistor 10c is provided so that the internal pressure of c becomes lower than that of the constant speed compressor 1b. As a result, between the variable speed compressor 1a and the constant speed compressor 1b, the internal pressure becomes lower when the discharge oil amount> the intake oil amount, regardless of the operating frequency of the variable speed compressor, and the discharge oil amount <the intake oil amount. Oil moves from the high pressure side compressor.
Since the constant speed compressor 1c is provided with a resistor 10c so that the internal pressure is lower than that of the constant speed compressor 1b, the constant speed compressor 1b is provided.
Move more. As shown in FIG. 5, when the oil equalizing pipes 11a and 11b are inserted into the compressor over a certain value, the oil moves to another compressor only when the oil equalizing pipe level position is reached. Disappears.

【0021】アキュームレータ9から各圧縮機1a,1
b,1cに到る吸入管の分岐部で油の分岐がうまくいか
ず、各圧縮機の油量が図6のケースAのように不均一に
なった場合、以下の運転を行い各圧縮機の油面を均一と
する。可変速圧縮機1aを高周波数で運転して圧縮機内
部圧力を低くし、定速圧縮機1cを停止することによっ
て油を圧縮機1a,1bに集める。次に可変速圧縮機1
aを低周波数で運転し圧縮機内部圧力を高くして、可変
速圧縮機1aの均油管以上の油を定速圧縮機1bへ移動
する。次に定速圧縮機1bを停止し定速圧縮機1cを運
転することによって定速圧縮機1bの均油管以上の油を
定速圧縮機1cへ移動する。各圧縮機の油量が図6のケ
ースBのような場合にも同様の動作を行うことによって
各圧縮機の油量を平均化することができる。また、定速
圧縮機を何台接続しても、軽負荷時停止側の圧縮機から
順次運転制御を行うことによって同様の結果となる。
From the accumulator 9 to the compressors 1a, 1a
When the oil is not properly branched at the branch portion of the suction pipe reaching b and 1c and the oil amount of each compressor becomes uneven as shown in case A of FIG. 6, the following operation is performed. To make the oil surface uniform. The variable speed compressor 1a is operated at a high frequency to reduce the internal pressure of the compressor, and the constant speed compressor 1c is stopped to collect oil in the compressors 1a and 1b. Next, the variable speed compressor 1
A is operated at a low frequency to increase the internal pressure of the compressor to move the oil above the oil equalizing pipe of the variable speed compressor 1a to the constant speed compressor 1b. Next, by stopping the constant speed compressor 1b and operating the constant speed compressor 1c, the oil above the oil equalizing pipe of the constant speed compressor 1b is moved to the constant speed compressor 1c. Even when the amount of oil in each compressor is the case B in FIG. 6, the same amount of oil in each compressor can be averaged by performing the same operation. Further, the same result can be obtained by sequentially controlling the operation of the compressors on the stop side at light load, regardless of how many constant speed compressors are connected.

【0022】図7は本発明の第2実施例に係る複数圧縮
機を備えた冷凍装置の回路図である。本装置において1
aは可変速圧縮機、2は可変速圧縮機1aの吐出側に設
けられた油分離器であり、分離された油分は吸入側へ戻
るようになっている。上記以外の部分の構成および作用
は第1実施例(図1)と同じである。
FIG. 7 is a circuit diagram of a refrigerating apparatus having a plurality of compressors according to the second embodiment of the present invention. In this device 1
Reference numeral a is a variable speed compressor, 2 is an oil separator provided on the discharge side of the variable speed compressor 1a, and the separated oil component is returned to the suction side. The structure and operation of the parts other than the above are the same as those of the first embodiment (FIG. 1).

【0023】本実施例においては、圧縮機から吐出され
る油分の大部分は油分離器2において分離され、前述の
如く各圧縮機に配分されるため油分離器2において分離
しきれずシステムを循環する油分の各圧縮機への配分が
必ずしも適性でなくても各圧縮機は適性油量を保有する
ことが可能となる。また、油分離器についても、従来技
術(図8)のように、各圧縮機について個々に設ける必
要がないため経済的なシステムとなる。
In the present embodiment, most of the oil discharged from the compressor is separated in the oil separator 2 and is distributed to each compressor as described above, so that the oil separator 2 cannot be completely separated and the system is circulated. Even if the distribution of the oil content to each compressor is not necessarily appropriate, each compressor can hold an appropriate amount of oil. Further, as for the oil separator, it is not necessary to individually provide each compressor as in the prior art (FIG. 8), so that the system is economical.

【0024】上記各実施例に共通して、各圧縮機の内部
圧力を調整するための絞りは、低負荷時の運転継続側の
圧縮機ほど抵抗が少なくなるようになっているため、負
荷が小さくなった時においても効率的な運転を行うこと
ができる。
In common with each of the above-mentioned embodiments, the throttle for adjusting the internal pressure of each compressor is designed so that the resistance of the compressor on the continuous operation side at the time of low load becomes smaller, so that the load becomes smaller. Efficient operation can be performed even when the size becomes small.

【0025】[0025]

【発明の効果】本発明の冷凍装置においては、複数台の
圧縮機を運転している時に、可変速圧縮機とそれに連結
された定速圧縮機の吐出油量と吸入油量とが等しくなる
可変速圧縮機の運転周波数で、可変速圧縮機の内部圧力
が、可変速圧縮機に均油管で連結された定速圧縮機の内
部圧力と等しくなるような抵抗を吸入管路に設け、か
つ、複数台接続された定速圧縮機の吸入管路には全圧縮
機運転時の軽負荷時に停止し易い側の圧縮機の内部圧力
が必ず低くなるような抵抗を各々設けると共に、圧縮機
内部圧力が可変速圧縮機と均油管で連結した定速圧縮機
から順次低くなる配列で各圧縮機を均油管で連結し、あ
るいは、さらに均油管が圧縮機の内壁から一定長さ以上
内側へ突出させて取り付けてあり、またさらに、複数台
の圧縮機の運転が一定時間経過した後、軽負荷時運転停
止側の圧縮機から順次停止した後、軽負荷時運転継続側
の圧縮機から順次一定時間運転を行う均油運転制御手段
を備えているので、各圧縮機において油が均等に保持さ
れ、従来油量の不均等が生じていた時の油量不足に伴う
故障を防止することができる。
In the refrigerating apparatus of the present invention, when operating a plurality of compressors, the discharge oil amount and the intake oil amount of the variable speed compressor and the constant speed compressor connected thereto become equal. At the operating frequency of the variable speed compressor, a resistance such that the internal pressure of the variable speed compressor is equal to the internal pressure of the constant speed compressor connected to the variable speed compressor by an oil equalizing pipe is provided in the suction pipeline, and , The suction pipes of multiple constant-speed compressors are equipped with resistances so that the internal pressure of the compressor on the side that tends to be stopped during light load during operation of all compressors will always be low. The pressure is gradually lowered from the constant speed compressor connected to the variable speed compressor with the oil equalizing pipe, and each compressor is connected with the oil equalizing pipe, or the oil equalizing pipe further protrudes inward from the inner wall of the compressor for a certain length or more. And installed, and moreover, the operation of multiple compressors is After the time has elapsed, the compressors on the light load operation stop side are sequentially stopped, and then the compressors on the light load operation continuation side are sequentially operated for a certain period of time. In this case, the oil is held evenly, and it is possible to prevent a failure due to a shortage of the oil amount when the conventional oil amount unevenness occurs.

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

【図1】本発明の第1実施例に係る冷凍装置の回路図。FIG. 1 is a circuit diagram of a refrigerating apparatus according to a first embodiment of the present invention.

【図2】上記実施例に関する圧縮機運転周波数と吐出油
量の関係図。
FIG. 2 is a diagram showing a relationship between a compressor operating frequency and a discharge oil amount according to the above embodiment.

【図3】上記実施例に関する吐出油量と吸入油量の関係
図。
FIG. 3 is a diagram showing the relationship between the amount of discharged oil and the amount of sucked oil in the above embodiment.

【図4】上記実施例に関する圧縮機運転周波数と圧縮機
内部差圧の関係図。
FIG. 4 is a diagram showing a relationship between a compressor operating frequency and a compressor internal differential pressure according to the above embodiment.

【図5】上記実施例に関する圧縮機断面と均油管固定位
置の図。
FIG. 5 is a view of a compressor cross section and an oil level pipe fixing position according to the above embodiment.

【図6】上記実施例に関する均油運転制御方法と各圧縮
機油量の図。
FIG. 6 is a diagram of an oil leveling operation control method and the amount of each compressor oil according to the above embodiment.

【図7】本発明の第2実施例に係る冷凍装置の回路図。FIG. 7 is a circuit diagram of a refrigerating apparatus according to a second embodiment of the present invention.

【図8】従来の冷凍装置の回路図。FIG. 8 is a circuit diagram of a conventional refrigeration system.

【符号の説明】[Explanation of symbols]

1a 可変速圧縮機 1b,1c 定速圧縮機 2 油分離器 3 四方切換弁 4 室外熱交換器 5 逆止弁 6 暖房用絞り 7a,7b,7c,7d 冷暖房用可変絞り 8a,8b,8c,8d 室内熱交換器 9 アキュームレータ 10b,10c 固定絞り 11a,11b 均油管 1a Variable speed compressor 1b, 1c Constant speed compressor 2 Oil separator 3 Four-way switching valve 4 Outdoor heat exchanger 5 Check valve 6 Heating throttle 7a, 7b, 7c, 7d Cooling and heating variable throttle 8a, 8b, 8c, 8d Indoor heat exchanger 9 Accumulator 10b, 10c Fixed throttle 11a, 11b Oil level pipe

───────────────────────────────────────────────────── フロントページの続き (72)発明者 北川 勝敏 愛知県西春日井郡西枇杷島町字旭町3丁目 1番地 三菱重工業株式会社エアコン製作 所内 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Katsutoshi Kitagawa 3-chome, Asahimachi, Nishibiwajima-cho, Nishikasugai-gun, Aichi Prefecture Mitsubishi Heavy Industries, Ltd. Air Conditioning Factory

Claims (3)

【特許請求の範囲】[Claims] 【請求項1】 1台の可変速圧縮機、同可変速圧縮機に
対して並列に接続された1台以上の定速圧縮機、凝縮
器、絞り、及び蒸発器を連結し、隣接した2台づつの圧
縮機を順次連結する均油管を設けた冷凍装置において、
複数台の圧縮機を運転している時に、可変速圧縮機とそ
れに連結された定速圧縮機の吐出油量と吸入油量とが等
しくなる可変速圧縮機の運転周波数で、可変速圧縮機の
内部圧力が、可変速圧縮機に均油管で連結された定速圧
縮機の内部圧力と等しくなるような抵抗を吸入管路に設
け、かつ、複数台接続された定速圧縮機の吸入管路には
全圧縮機運転時の軽負荷時に停止し易い側の圧縮機の内
部圧力が必ず低くなるような抵抗を各々設けると共に、
圧縮機内部圧力が可変速圧縮機と均油管で連結した定速
圧縮機から順次低くなる配列で各圧縮機を均油管で連結
したことを特徴とする冷凍装置。
1. A variable speed compressor, one or more constant speed compressors connected in parallel to the variable speed compressor, a condenser, a throttle, and an evaporator are connected to each other and adjacent to each other. In a refrigeration system provided with an oil equalizing pipe that sequentially connects the compressors one by one,
When operating multiple compressors, the variable speed compressor and the constant speed compressor connected to the variable speed compressor are operated at the operating frequency of the variable speed compressor at which the discharge oil amount and the intake oil amount are equal. The suction pipe of a constant-speed compressor in which a plurality of units are connected is provided with a resistance so that the internal pressure of the equalizer becomes equal to the internal pressure of the constant-speed compressor connected to the variable-speed compressor by an oil equalizing pipe. Each road is equipped with a resistance that reduces the internal pressure of the compressor on the side that is easy to stop when the load is light during full-compressor operation.
A refrigeration system in which each compressor is connected by an oil equalizing pipe in an array in which the internal pressure of the compressor is gradually lowered from a constant speed compressor connected by a variable speed compressor with an oil equalizing pipe.
【請求項2】 請求項1に記載の冷凍装置において、均
油管が圧縮機の内壁から一定長さ以上内側へ突出させて
取り付けられていることを特徴とする冷凍装置。
2. The refrigerating apparatus according to claim 1, wherein the oil equalizing pipe is attached so as to project inward from the inner wall of the compressor by a predetermined length or more.
【請求項3】 請求項1に記載の冷凍装置において、複
数台の圧縮機の運転が一定時間経過した後、軽負荷時運
転停止側の圧縮機から順次停止した後、軽負荷時運転継
続側の圧縮機から順次一定時間運転を行う均油運転制御
手段を備えたことを特徴とする冷凍装置。
3. The refrigerating apparatus according to claim 1, wherein after a plurality of compressors have been operated for a certain period of time, the compressors on the light load operation stop side are sequentially stopped, and then the light load operation continuation side. Refrigerating apparatus comprising: an oil-equalizing operation control unit that sequentially operates for a predetermined time from the compressor.
JP5177937A 1993-07-19 1993-07-19 Refrigerating device Withdrawn JPH0735425A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP5177937A JPH0735425A (en) 1993-07-19 1993-07-19 Refrigerating device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP5177937A JPH0735425A (en) 1993-07-19 1993-07-19 Refrigerating device

Publications (1)

Publication Number Publication Date
JPH0735425A true JPH0735425A (en) 1995-02-07

Family

ID=16039678

Family Applications (1)

Application Number Title Priority Date Filing Date
JP5177937A Withdrawn JPH0735425A (en) 1993-07-19 1993-07-19 Refrigerating device

Country Status (1)

Country Link
JP (1) JPH0735425A (en)

Cited By (8)

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Publication number Priority date Publication date Assignee Title
JP2008309438A (en) * 2007-06-18 2008-12-25 Panasonic Corp Refrigeration cycle device
JP2010071568A (en) * 2008-09-19 2010-04-02 Mitsubishi Electric Corp Refrigeration system
WO2010113933A1 (en) 2009-03-31 2010-10-07 三菱重工業株式会社 Turbo refrigeration machine and method for controlling the same
JP2010255859A (en) * 2009-04-21 2010-11-11 Mitsubishi Electric Corp Refrigerating device
CN102954624A (en) * 2012-11-27 2013-03-06 大连三洋压缩机有限公司 Parallel compressor oil return device and control method
CN105588191A (en) * 2015-05-05 2016-05-18 海信(山东)空调有限公司 Indoor unit, air conditioning system and control method
WO2017170356A1 (en) * 2016-03-28 2017-10-05 三菱重工サーマルシステムズ株式会社 Multistage compression device, refrigeration cycle comprising same, and operation method for multistage compression device
WO2017170329A1 (en) * 2016-03-28 2017-10-05 三菱重工サーマルシステムズ株式会社 Multistage compression device, refrigeration cycle comprising same, and operation method for multistage compression device

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008309438A (en) * 2007-06-18 2008-12-25 Panasonic Corp Refrigeration cycle device
JP2010071568A (en) * 2008-09-19 2010-04-02 Mitsubishi Electric Corp Refrigeration system
WO2010113933A1 (en) 2009-03-31 2010-10-07 三菱重工業株式会社 Turbo refrigeration machine and method for controlling the same
JP2010255859A (en) * 2009-04-21 2010-11-11 Mitsubishi Electric Corp Refrigerating device
CN102954624A (en) * 2012-11-27 2013-03-06 大连三洋压缩机有限公司 Parallel compressor oil return device and control method
CN105588191A (en) * 2015-05-05 2016-05-18 海信(山东)空调有限公司 Indoor unit, air conditioning system and control method
CN105588191B (en) * 2015-05-05 2019-03-05 海信(山东)空调有限公司 A kind of indoor unit, air-conditioning system and control method
WO2017170356A1 (en) * 2016-03-28 2017-10-05 三菱重工サーマルシステムズ株式会社 Multistage compression device, refrigeration cycle comprising same, and operation method for multistage compression device
WO2017170329A1 (en) * 2016-03-28 2017-10-05 三菱重工サーマルシステムズ株式会社 Multistage compression device, refrigeration cycle comprising same, and operation method for multistage compression device
JP2017180878A (en) * 2016-03-28 2017-10-05 三菱重工サーマルシステムズ株式会社 Multistage compression device, refrigeration cycle including the same, and operation method of multistage compression device

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