EP1550832A1 - A (compound) refrigeration system and method for operating the (compound) refrigeration system - Google Patents

Abstract

The system has several compressors on two or more levels (E1,E2), whereby the compressors on the same level are connected together by an oil balancing line (1,2), and at least one container (B1,B2) per level dimensioned to at least hold the required minimum oil quantity per level and connected to the oil balancing line for their respective levels. The container on the lowest level is connected to its oil balancing line with a shut-off capability and to the pressure side of the system via a pressure line (4) with a shut-off capability. The containers are connected together by a connecting line (5) that is connected to the container in the upper level so that the container is only operated up to the desired oil level in the upper level. An independent claim is also included for a method of operating an inventive system.

Description

The invention relates to a composite (refrigeration) system, comprising several, two or more levels arranged compressors, which arranged on a plane Compressors are connected to each other via an oil equalization line.

Furthermore, the invention relates to a method for operating such plant Compound (refrigeration).

Under the term "container" used below are in addition to conventional Containers also suitable recording or (intermediate) storage devices, such as For example, pieces of pipe, for the recording or (intermediate) storage of Liquid quantities are suitable to understand.

The term "composite (cold) plant" is one as described below Compound refrigeration system as well as compound systems, the compression of any media for serve other purposes, to understand.

In composite (cold) systems of the generic type provides the reliable Oil supply to the compressor, in a common refrigerant or Refrigerant mixture cycle work, often a problem dar. To ensure A reliable oil supply are so far different Oil level control systems, such as oil level regulators used. These However, they are subject to wear and tear and require other systems Adjustments to the oil system during commissioning.

German Patent Applications 198 23 524 and 198 23 525 disclose methods for oil equalization between compressors, which are arranged on a plane known. Problematic is an oil balance between several Verdichtem whenever the compressors are arranged on two or more levels. An arrangement more compressors on two or more levels is particularly advantageous or even required if a large number of compressors on one comparatively small footprint must be accommodated. This is for example, in narrow engine rooms or in an outdoor installation, ie then, if the compressors in a housing - possibly together with the or the condensers - are arranged, the case.

Object of the present invention is to provide a generic Composite (cold) plant and a generic method for operating a specify such composite (refrigeration) system, in or on the use wear-prone and trouble-prone Ölspiegelreguliersysteme omitted, the Lubricating oil supply of all compressors made more reliable and the manufacturing costs can be lowered.

a) pro Ebene wenigstens ein Behälter vorgesehen ist,

b) die Behälter derart dimensioniert sind, dass sie wenigstens die pro Ebene erforderliche Mindestölmenge aufnehmen können,

c) die Behälter jeweils mit der Ölausgleichsleitung ihrer Ebene verbunden sind,

d) wobei der Behälter der untersten Ebene mit der zugehörigen Ölausgleichsleitung absperrbar verbunden ist,

e) der Behälter der untersten Ebene über eine Druckleitung mit der Druckseite der Verbund(kälte)anlage absperrbar verbunden ist, und

f) die Behälter über eine Verbindungsleitung miteinander verbunden sind,

g) wobei die Verbindungsleitung an dem Behälter der oberen Ebene derart angeordnet ist, dass der Behälter nur bis zu dem in der oberen Ebene gewünschten Ölstand entleert wird.

The composite (refrigeration) plant according to the invention is characterized in that

a) at least one container is provided per level,

b) the containers are dimensioned such that they can accommodate at least the minimum quantity of oil required per level,

c) the containers are each connected to the oil equalization line of their level,

d) wherein the container of the lowest level is connected shut-off with the associated oil compensation line,

e) the container of the lowest level via a pressure line to the pressure side of the composite (cold) system is connected shut-off, and

f) the containers are connected to one another via a connecting line,

g) wherein the connecting line is arranged on the container of the upper level such that the container is only emptied to the level desired in the upper level.

a') zu Beginn eines Ölausgleiches zwischen den Verdichtern alle Verdichter abgeschaltet werden und die zwischen der Ölausgleichsleitung und dem Behälter der unteren Ebene angeordnete Absperrvorrichtung, sofern sie geschlossen ist, geöffnet wird,

b') die Verdichter so lange abgeschaltet bleiben, bis zwischen den Verdichtem jeder Ebene und über die Verbindungsleitung zwischen den Ebenen ein Ölausgleich erfolgt ist,

c') nach Abschluss des Ölausgleiches die zwischen der Ölausgleichsleitung und dem Behälter der unteren Ebene angeordnete Absperrvorrichtung geschlossen wird,

d') ein oder mehrere Verdichter der unteren Ebene in Betrieb genommen werden,

e') die in der Druckleitung angeordnete Absperrvorrichtung geöffnet wird,

f) wobei die Absperrvorrichtung so lange geöffnet bleibt, bis ein ggf. erforderlicher Ölausgleich zwischen den Behältern erfolgt ist, und

g') nach erfolgtem Ölausgleich die zwischen der Ölausgleichsleitung und dem Behälter der unteren Ebene angeordnete Absperrvorrichtung geöffnet wird.

The inventive method for operating a composite (cold) plant is characterized in that

a ') at the beginning of an oil equalization between the compressors, all compressors are switched off and the shut-off device arranged between the oil equalizing pipe and the lower-level tank, if it is closed, is opened,

b ') the compressors remain switched off until an oil balance has taken place between the compressors of each level and via the connecting line between the levels,

c ') after completion of the oil equalization, the shut-off device located between the oil equalizing pipe and the lower-level tank is closed,

d ') one or more compressors of the lower level are put into operation,

e ') the shut-off device arranged in the pressure line is opened,

f) wherein the shut-off device remains open until a possibly required oil balance between the containers has taken place, and

g ') after the oil equalization between the oil equalization line and the container of the lower level arranged shut-off device is opened.

The inventive composite (cold) plant, the inventive method for Operating a composite (refrigeration) system and other embodiments of the or the same will be described below with reference to FIG Embodiment explained in more detail.

Shown in the figure are two compressor levels E1 and E2, below only to be called "levels". In each of the two levels E1 and E2 are three compressors V1, V2 and V3 (level E1) and V4, V5 and V6 (level E2) arranged.

In principle, the compressors of a composite (refrigeration) plant can also be used in three, four or three more levels are arranged. In addition, per level, in principle, one any number of compressors are provided. Also, on the individual Planes different compressors are used, only they should - if possible - be of the same design.

Per level E1 or E2 is now according to the invention now at least one container B1 or B2 provided. These containers B1 and B2 are dimensioned such that they to record at least the minimum oil fill required per level E1 or E2 capital. The containers B1 and B2 are above the respective oil equalization lines. 1 (and line section 3) and 2 with their associated compressors V1 to V3 or V4 to V6 connected to their level.

Here, the lines 1 and 2 preferably run centrally to the sight glasses of Compressors V1, V2 and V3 or V4, V5 and V6. The containers B1 and B2 are also in advantageously in the middle between the compressors V1, V2 and V3 or V4, V5 and V6 their level E1 or E2 arranged. The puncture of lines 3 and 2 in the container B1 and B2 is preferably carried out centrally to the sight glasses of the compressor V1, V2 and V3 or V4, V5 and V6. This will ensure that the oil level in the containers B1 or B2 approximately equal to that in the compressors V1, V2 and V3 or V4, V5 and V6 prevailing oil levels.

According to the invention between the oil equalization line 1 of the lowest level E1 and the storage container B1 associated with this level E1 has a shut-off device a provide; this is usually as a shut-off valve, preferably as a Solenoid valve, be formed.

Further, the container B1 is the lowest level E1 via a pressure line 4 with the Pressure side of the Verbund (refrigeration) system can be shut off - as a rule realized by a Shut-off device b - connected.

The two containers B1 and B2 are in turn connected via a connecting line 5 connected with each other. The connecting line 5 can be made lockable be; not shown in the figure.

If there are more than two levels and thus more than two containers, that is it sufficient if the container is one level with the container of each below it and the container is connected to the respective overlying level.

The connecting line 5 is in this case on the container B2 of the upper level E2 to arrange that the container B2 during the oil balance only up to that in the upper level E2 required oil level is emptied.

The composite (refrigeration) plant according to the invention is further proposed that at least one of the containers via a suction line with the suction side of Composite (cold) system is connected lockable. The suction line (s) must or must be lockable, since during operation different pressure levels in the compressor housings and the suction line.

In the embodiment shown in the figure, both containers B1 and B2 are over Suction lines 6 and 7, in each of which a shut-off c or d arranged is connected. Connecting the container B1 and / or B2 via suction lines 6 and 7 with the suction side of the composite (refrigeration) plant serves the purpose of the or the container To be able to degas B1 and B2. This may be necessary if the inventive composite (cold) system, for example, at high Operating ambient temperature and it is to evaporate the Refrigerants (mixtures) s comes from the oil. This evaporated refrigerant (mixture) can then be derived via the suction lines 6 and 7 to the suction side, whereby a trouble-free oil balance between the Verdichtem and individual Levels can be guaranteed. It has been shown that in normal Room temperatures this degassing is usually not required.

Advantageously, the composite (refrigeration) plant according to the invention is the compressor V1, V2 and V3 or V4, V5 and V6 one level respectively Assigned to the oil level regulation system. In principle, all the state of the Technology-counting oil level control systems are used.

In the composite (refrigeration) system according to the invention or the realization of the The procedure according to the invention can be based on the provision of conventional Ölspiegellreguliersysteme be waived. U. U. However, there may be applications in which such oil level control continue to be used come.

Now, between the compressors V1, V2, ..... of the two levels E1 and E2 a Oil equalization are performed, so first all the compressors V1, V2, ..... shut off and between the oil balance line 1 and the container B1 of Shut-off device a arranged on the lower level E1, if this during the Normal operation was closed, open. This can be an oil balance between the individual compressors V1, V2, .... each level with each other and an oil balance take place between the containers B1 and B2 via the line connecting them 5.

If there is too much oil on the upper level E2, this gets over the between the containers E1 and E2 arranged connecting line 5 from the upper to the lower level E1 and thus - since the shut-off a is open - on the line section 3 to the compressors V1, V2 and V3. To prevent that the compressors V4, V5 and V6 of the upper level E2 now idle, must - like already mentioned - the connection line 5 to the container B2 of the upper level E2 be arranged such that the container B2 only up to that in the upper level E2 desired (minimum) oil level can be emptied. If the containers B1 and B2 connecting line 5 is formed lockable, this must during the be open above method step.

After completion of the above oil balance is between the Oil equalization line 1 and the container B1 of the lower level E1 arranged Shut-off a closed again; subsequently one or more Compressor V1, V2 and / or V3 of the lower level E1 put into operation.

At the same time or with a time delay, one or more Compressors V4, V5 and / or V6 of the upper level E2 are put into operation.

By commissioning one or more compressors V1, V2 and / or V3 of the At the lower level E1 there is once again one within the Verbund (cold) plant Pressure build-up, so that after opening arranged in the pressure line 4 Shut-off b the flowing through the pressure line 4 in the container B1, under Pressurized gas oil from the lower tank E1 via the connecting line 5 in pushes the upper container B2. By means of this process step is ensured that a possibly existing on the upper level E2 lack of oil are compensated can.

The arranged in the pressure line 4 shut-off b remains so long opened until the possibly required oil balance between the containers B1 and B2 or the planes E1 and E2 and the compressors V4, V5 and V6 is done.

During the above-described oil equalization phase, the compressors remain V4, V5 and V6 of the upper level E2 preferably still switched off, so that (also) between a sufficient oil balance can take place. Unless in the upper level E2 too much oil is present, this passes through the connecting line 5 again in the lower container B1 and to the lower level E1.

Since at least one or more during the above-described method step Compressor V1, V2 and / or V3 of the lower level E1 are operated stands at least part of the refrigeration capacity to be provided by means of the composite refrigeration system again available.

After the oil balance is now between the oil equalization line 1 and the Container B1 of the lower level E1 arranged shut-off a again opened and it will - if this has not already happened in the meantime - the still switched off compressor V4, V5 and / or V6 of the upper level E2 in operation taken.

The method according to the invention described above is always realized if by appropriate measures in at least one of the compressors V1, V2, ... an oil shortage is detected. Here, the monitoring of oil levels in the Compressed manually and / or automatically. Likewise, the initiation can also an oil equalization phase manually and / or automatically performed. moreover is usually compulsory at certain, adjustable intervals Oil equalization initiated.

The operating times of the compressors V1, V2, .... until their shutdown are here too select that the minimum allowable oil level within the compressor due to the inevitably occurring during compressor operation oil displacement is not yet is fallen short of. The stoppage phases of the compressors must be timed in this way be ensured that a sufficient oil balance between the compressors can be and a significant impairment of the refrigeration by the Compressor of the composite (refrigeration) system according to the invention is avoided.

The composite (refrigeration) system according to the invention and the method according to the invention to operate a composite (refrigeration) plant create over the prior art significant improvements, as on wear-prone and trouble-prone Ölspiegelreguliersysteme can be omitted. This will reduce the manufacturing costs inventive compound (refrigeration) systems lowered and at the same time becomes a Reliable lubricating oil supply all compressors of the invention Composite (refrigeration) system guaranteed.

Claims (6)

Composite (refrigeration) system, comprising a plurality of compressors arranged on two or more levels, wherein the compressors arranged on a plane are connected to each other via an oil equalization line, characterized in that a) at least one container (B1, B2) is provided per level (E1, E2), b) the containers (B1, B2) are dimensioned such that they can accommodate at least the minimum quantity of oil required per level (E1, E2), c) the containers (B1, B2) are each connected to the oil equalization line (1, 2) of their plane (E1, E2), d) wherein the container (B1) of the lowest level (E1) with the associated oil equalization line (1) lockable (a) is connected, e) the container (B1) of the lowest level (E1) via a pressure line (4) with the pressure side of the composite (cold) plant shut-off (b) is connected, and f) the containers (B1, B2) are connected to one another via a connecting line (5), g) wherein the connecting line (5) on the container (B2) of the upper level (E2) is arranged such that the container (B2) is emptied only up to the in the upper level (E2) desired oil level. Composite (refrigeration) system according to claim 1, characterized in that at least one of the containers (B1, B2) via a suction line (6, 7) with the suction side of the composite (cold) system shut-off (c, d) is connected. Composite (refrigeration) system according to claim 1 or 2, characterized in that the Verdichtem (V1, V2, ...) of a plane (E1, E2) is assigned in each case a Ölspiegelreguliersystem. Composite (cold) installation according to one of the preceding Claims 1 to 3, characterized in that the containers (B1, B2) are connected to one another in a lockable manner. Method for operating a composite refrigeration system according to one of the preceding claims, characterized in that a ') at the beginning of an oil equalization between the compressors (V1, V2, ...) all compressors (V1, V2, ...) are switched off and the between the oil equalization line (1) and the container (B1) of the lower level ( E1) arranged shut-off device (a), if it is closed, is opened, b ') the compressors (V1, V2, ...) remain switched off until between the compressors (V1, V2, ...) of each level (E1, E2) and via the connecting line (5) between the levels ( E1, E2) an oil balance has taken place, c ') after completion of the oil equalization, the shut-off device (a) disposed between the oil equalizing line (1) and the lower-level tank (B1) (E1) is closed, d ') one or more compressors (V1, V2, V3) of the lower level (E1) are put into operation, e ') in the pressure line (4) arranged shut-off device (b) is opened, f) wherein the shut-off device (b) remains open until a possibly required oil balance between the container (B1, B2) has taken place, and g ') after the oil balance has been completed, the shut-off device (a) arranged between the oil equalizing line (1) and the container (B1) of the lower level (E1) is opened. A method according to claim 5, characterized in that with or after the commissioning of one or more of the compressors (V1, V2, V3) of the lower level (E1) one or more compressors (V4, V5, V6) of the upper level (E2) in Operation.

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