EP3394449A2

EP3394449A2 - Refrigerant compressor system

Info

Publication number: EP3394449A2
Application number: EP16823266.8A
Authority: EP
Inventors: Christian Scharer; Thomas Varga
Original assignee: Bitzer Kuehlmaschinenbau GmbH and Co KG
Current assignee: Bitzer Kuehlmaschinenbau GmbH and Co KG
Priority date: 2015-12-21
Filing date: 2016-12-20
Publication date: 2018-10-31
Anticipated expiration: 2036-12-20
Also published as: CN108291545A; WO2017108812A2; DE102015122443A1; US20180298905A1; DE102015122443B4; CN108291545B; US10968913B2; WO2017108812A3; EP3394449B1

Abstract

Disclosed is a refrigerant compressor system comprising at least three compressors which are arranged in parallel between a suction line and a pressure line and each of which includes a lubricant sump unit; during operation, the compressors operate in such a way that the pressures in the lubricant sump units of the compressors form a pressure cascade in which the compressors have a gradually slightly decreasing pressure in the associated lubricant sump units in a defined cascade sequence; the lubricant sump units are connected to each other according to the cascade sequence by means of a lubricant line system in order for lubricant to be delivered, and each lubricant sump unit includes a connection to which an insertion element is connected, the insertion element establishing a connection to the lubricant line system and being designed in such a way as to set, for the associated lubricant sump unit, a lubricant level from which lubricant is delivered to the subsequent lubricant sump unit in the cascade sequence.

Description

REFRIGERANT COMPRESSOR SYSTEM

The invention relates to a refrigerant compressor system comprising at least three compressors arranged in parallel between a suction line and a pressure line, each of which has a lubricant sump unit.

In such refrigerant compressor systems, there is a need to provide all the compressors with sufficient lubricant.

This object is achieved in a refrigerant compressor system of the type described above according to the invention, that the compressors operate in operation so that the respective pressures in the respective lubricant sump units of each compressor result in a pressure cascade, according to which the compressor in a defined cascade order a stepwise slightly lower Pressure in the respective

Having lubricant sump unit that the lubricant sump units are connected to each other according to the cascade order for lubricant transport with a lubricant line system and that each lubricant sump unit has a port to which an insert element is connected, which connects on the one hand to the lubricant line system and on the other hand is adapted to the respective Lubricant sump unit specifies a lubricant level above which a lubricant is transported to the next in the cascade sequence lubricant sump unit.

The advantage of the solution according to the invention is particularly to be seen in the fact that with this the possibility exists, due to the adjusting

Pressure cascade in the cascade sequence to ensure adequate supply of all lubricant sump units with lubricant, which is ensured by the predetermined lubricant level, that in the individual lubricant sump units a sufficient amount of

Lubricant is present. To determine the predetermined lubricant level is preferably provided that each insert element has a direction of gravity above the respective predetermined lubricant level level orifice of a leading to the lubricant line system lubricant channel, so that when the amount of lubricant in the respective lubricant sump unit exceeds the predetermined lubricant level, the lubricant through the orifice and the lubricant channel may enter the lubricant line system to flow to the next in the cascade sequence lubricant sump unit.

Furthermore, it is favorable, in particular, if the lubricant sump unit is to be designed such that this lubricant is supplied from another lubricant sump unit, if the insert elements of the compressors lying in the cascade sequence between two compressors have a discharge opening in the direction of gravity below the predetermined lubricant level of a lubricant line system Has lubricant channel, said lubricating channel and this orifice is the opportunity to supply the corresponding lubricant sump unit lubricant, which comes from a preceding in the cascade sequence lubricant sump unit.

Advantageously, it is provided that the outlet opening lying in the direction of gravity above the predetermined level of lubricant level and the outlet opening lying in the direction of gravity below the predetermined lubricant level in the direction parallel to the direction of gravity are spaced apart.

In order to be able to detect the lubricant level of the respective lubricant sump unit for maintenance and monitoring purposes, a sensor is provided, for example, with which the lubricant level can be detected. It is preferably provided that each insert element is a visualization unit for visualizing the lubricant level of the respective

Having lubricant sump unit.

By way of example, the visualization unit is designed such that it provides an image indicating the lubricant level, which image is generated, for example, by electronic or optical imaging.

In particular, it is expedient for reasons of a simple solution if the visualization unit comprises a sight glass adjoining a lubricant bath extending into the insert element of the respective lubricant sump unit, in which the lubricant level can be seen.

Furthermore, it is preferably provided that each insert element a

Visualization unit for visualizing a lubricant flow to another lubricant sump unit has.

For this purpose too, it is preferably provided that the visualization unit comprises a sight glass, which can detect a lubricant flow to the lubricant line system.

With regard to the design of the lubricant line system, no details have been given so far.

In principle, the lubricant line system could be designed such that it comprises a lubricant line with branches leading to each of the insert elements. A particularly advantageous solution provides that the lubricant line system comprises in each case in the cascade sequence successive insert elements connecting connecting lines, so that each of the connecting lines connects only two successive insert elements together.

In particular, it is provided in this case that the connecting line in each case one of the mouth openings having lubricant channel of an insert element with a, one of the mouth openings having lubricant channel of the other insert element connects.

In the case of insert elements, which has a lubricant channel with a direction of gravity above the predetermined lubricant level and a lying in the direction of gravity with a below the respective predetermined lubricant level level orifice, it is provided that the connecting line is a connection between the lubricant channel with a gravity direction above the predetermined Lubricant level lying outlet opening and the lubricant channel with a below the respective predetermined lubricant level level produces orifice so that thereby the inflow to the respective lubricant bath via the respective predetermined lubricant level level opening takes place and an outflow from the respective lubricant bath by lying above the predetermined lubricant level Mouth opening occurs, which in particular means that at the over tion of lubricant from one lubricant sump unit to the other lubricant sump unit as little as possible turbulence of this lubricant takes place.

With regard to the formation of the pressure cascade in the individual lubricant sump units, no further details have been given so far. Thus, it is preferably provided that the pressure level in the respective lubricant sump unit of the respective compressor is determined by the formation of the suction line.

In particular, an expedient design of the compressor provides that these are designed so that the pressure in the respective lubricant sump unit is correlated with the suction pressure of the respective compressor.

It is particularly useful if the pressure in the respective

Lubricant sump unit corresponds to the suction pressure of the respective compressor.

The invention can be implemented particularly advantageously when the connection to which the insert element is connected is a standard connection for detecting the lubricant level.

With regard to the supply of the individual compressors so far, no further details have been made.

Thus, it is preferably provided that the intake manifold is formed so that a first compressor in the cascade sequence of the intake manifold is supplied with the largest amount of lubricant, that is, that the intake manifold is formed so that in this settling lubricant in the first compressor in the cascade order occurs.

Furthermore, it is preferably provided that the intake pipe system is designed so that the following in the cascade sequence to the first compressor compressors obtain smaller amounts of lubricant from the intake manifold. In particular, it is provided that the suction line system is designed so that the successive in the cascade sequence compressor according to their position in the cascade order each receive smaller amounts of lubricant from the intake manifold.

With regard to the operation of the individual compressors of the refrigerant compressor system, in particular when individual of the compressors are to be switched off, no further details have been given so far.

Thus, it is provided in particular that the refrigerant compressor installation has a control for the individual compressors, which ensures that individual compressors are switched off, that the still working compressors are always arranged side by side in the cascade sequence.

Further features and advantages of the inventive solution are the subject of the following description and the drawings of some embodiments.

In the drawing show:

1 shows a side view of a refrigerant compressor plant according to the invention;

2 is a plan view of the refrigerant compressor plant in the direction of

Arrow A in Fig. 1;

Fig. 3 is a vertical section through an exemplary compressor of

Refrigerant compressor apparatus;

4 shows an illustration of the refrigerant compressor system with the pressure cascade forming in the individual compressors of the refrigerant compressor system; Fig. 5 is an enlarged view of the area B in Fig. 3;

6 is a view of an insert element in the direction of the arrow C in FIG. 5;

Fig. 7 is a perspective view of the insert element;

Figure 8 is a schematic representation of the insert element in relation to a lubricant bath whose bath surface is below a predetermined lubricant level.

9 is a representation corresponding to FIG. 8, wherein the bath surface of

Lubricant bath is so high that the bath surface is visible in a sight glass of the insert element;

10 is a representation corresponding to FIG. 8, wherein the bath surface of the

Lubricant bath reaches the predetermined lubricant level;

11 is a view similar to FIG. 8, wherein the bath surface of

Lubricant bath is higher than the predetermined lubricant level, so that lubricant via the insert element in the

Lube line system and flows from the lubricant line system in the next compressor and

12 is an illustration of the refrigerant compressor system similar to FIG. 1 with

Representation of the individual insert elements and the connecting lines of the lubricant line system between the individual insert elements.

An embodiment of a refrigerant compressor system 10 shown as a whole in FIGS. 1 and 2 comprises a plurality, for example four, compressors 12a to 12d, which are arranged in parallel between a common intake line 14 and a common pressure line 16 and in Operate in parallel, from the common intake 14 each individual intake 22a to 22d lead to the individual compressors 12a to 12d, which form an intake manifold 20 with the intake manifold 14.

Furthermore, from the compressors 12a to 12d, individual pressure lines 24a to 24d lead to the common pressure line 16.

The compressors 12a to 12d are preferably constructed identically, wherein each of these compressors 12 has an outer housing 32, in which a

Compressor unit 34, for example in the form of a scroll compressor unit with two interlocking spiral members 36 and 38, is provided, for example, the spiral body 36 is fixedly arranged in the outer housing 32, while the spiral body 38 is orbitally driven.

To drive the compressor unit 34, a drive motor designated as a whole by 42 is provided in the outer housing 32, which drives the spiral body 38 via an eccentric drive 44.

Trained as an electric motor drive motor 42 comprises a stator 46 and a rotor 48 which sits on a drive shaft 52 which in turn relative to the outer housing 32 rotatably mounted in bearing units 54 and 56 around a

Drive shaft axis 58 is rotatably mounted.

The drive shaft 52 is provided for example with a lubricant channel 62 which extends at a slight angle to the drive shaft axis 58 from a first drive shaft end 64 to a second drive shaft end 66, the second drive shaft end 66 is associated with the eccentric 44 and thus via the lubricant passage 62, a lubrication of Eccentric 44 takes place. The first drive shaft end 64 faces a lubricant sump unit, indicated as a whole by 72, which is formed in a gravitationally low region of the outer housing 32, in the present case a compressor with a substantially vertically extending drive shaft axis 58, by a cup-shaped bottom body 74 of the outer housing 32. wherein in the bottom body 74, a lubricant bath 76 is formed, which extends to a bath surface 78, which preferably still lies within the bottom body 74 and their location in the direction of gravity can detect the lubricant level.

In this case, the bottom body 74 in particular represents an end-side termination of a cylindrical jacket body 82 of the outer housing 32, which is closed on the side opposite the bottom body 74 by a lid body 84.

For sucking lubricant from the lubricant bath 76 in the

Lubricant channel 62 extends from the first drive shaft end 64 of the drive shaft 52, a suction nozzle 86 into the lubricant 76 in so that it is able to absorb lubricant below the bath surface 78 of the lubricant 76 and the lubricant channel 62 feed, in particular the pumping action at rotating drive shaft 52 of the lubricant through the obliquely to

Drive shaft axis 58 extending lubricant channel 62 and the centrifugal forces occurring thereby takes place.

The outer housing 32 is preferably in the area between the

Compressor unit 34 and the lubricant sump unit 72 with a suction port 92 which is connected to the corresponding Einzelsaugleitung 22. The refrigerant entering through the suction port 92 into the outer housing 32, which also carries lubricant, enters a suction chamber 94 surrounding the drive motor 42, and flows with simultaneous cooling of the drive motor 42 in the direction of the compressor unit 34, wherein in the suction chamber 94 within the Outer housing 32 a

Deposition of lubricant takes place, which then flows in the direction of gravity then to the lubricant sump unit 72 and collects in the lubricant bath 76.

Thus, the lubricant portion of the entering into the compressor unit 34 refrigerant is significantly reduced and the lubricant is after the

Reaching the lubricant bath 76 for the lubrication of the compressor unit 34, in particular of the eccentric drive 44 available.

The refrigerant compressed in the compressor unit 34 then exits into a pressure chamber 96 located near or adjacent to the lid body 84, from which it then passes via the respective individual pressure line 24 into the common pressure line 16.

Due to the separation of the lubricant from the refrigerant flow in the suction chamber 94, which is above the lubricant 76, is present in the lubricant sump unit 72, the lubricant under a pressure which is present at the suction port 92 suction pressure PS of the refrigerant and also substantially the suction pressure of corresponds to the compressor unit 34 sucked refrigerant.

The lubricant sump unit 72, for example, is in turn provided with a port 102, which is usually a standard port for a sight glass for detecting the level of lubricant, in which in the present embodiment a 104 denoted as a whole in the present embodiment

Insert element is used, which will be described in more detail below. The connection 102 is arranged on the outer housing 32 in such a way that it adjoins the lubricant bath 76 and, in particular, the connection 102 extends on both sides of the bath surface 78 at a predetermined lubricant level.

As shown in FIGS. 1 and 2, each of these insert elements 104a to 104c of the respective compressor 12a to 12d connects to a lubricant line system designated as a whole by 112, which respectively comprises connecting lines 114i, 114 ₂ , 114 ₃ extending between two insert elements 104 In the exemplary embodiment illustrated, the refrigerant compressor system 10 with a total of four compressors 12a to 12d connects the connecting line 114i, the insert elements 104a and 104b, the connecting line 114 ₂ , the insert elements 104b and 104c and the

Connecting line 114 ₃ , the insert elements 104c and 104d connects.

Thus, the lubrication line system 112 with the connection lines 114i, 114 ₂ and 114 ₃ together with the insert elements 104a, 104b, 104c and 104d as a whole constitutes a composite system between the individual lubricant sump units 72 of the individual compressors 12a, 12b, 12c and 12d to a sufficient distribution of the lubricant via the various lubricant sump units 72, as will be described in detail below.

As shown in FIG. 4, in the refrigerant compressor apparatus 10 of the present invention, the common intake pipe 14 having the single intake passages 22a to 22d opening into it is formed such that one of the compressors 12, for example the compressor 12a, within the outer casing 32 has a suction pressure PSa is greater than the suction pressure PSb in the compressor 12b, which in turn is in turn greater than the suction pressure PSc in the compressor 12c wherein this suction pressure PSc is in turn greater than the suction pressure PSd in the compressor 12d. Since the suction pressures PSa, PSb, PSc and PSd also correspond to the respective pressure in the respective lubricant sump unit 72a, 72b, 72c, 72d, the lubricant in the respective lubricant sump units 72a, 72b, 72c and 72d is thus under a different pressure (FIG. 4).

Thus, the pressures PSa, PSb, PSc and PSd together form a pressure cascade DK in each case in stages of lower pressures, with a cascade sequence KR which extends from the lubricant sump unit 72a to the lubricant sump unit 72d.

For example, the pressure PSa on the order of one or a few tenths of a bar is greater than the pressure PSb, which in turn is greater than the pressure PSc by one or a few tenths of a bar and the pressure PSc is again greater by one or a few tenths of a bar the pressure PSd, as shown in Fig. 4, so that the pressure cascade DK is formed, in which, in a cascade direction KR, the pressure of the respective one

Lubricant sump unit 72 gradually decreases to the next in the cascade sequence KR next lubricant sump unit 72.

The highest pressure level PSa in the compressor 12a and thus in the lubricant sump unit 72a can be achieved by virtue of the fact that, in the case of a suction line 14 with a constant cross-section from which the compressors 12 sequentially draw off refrigerant, this is the last refrigerant-sucking

Compressor is so that the flow velocity of the refrigerant in the suction pipe 14 at the transition to the single suction pipe 22a is the lowest, while, for example, the first compressor 12d with the single suction pipe 22d from the common intake pipe 14 draws refrigerant from the maximum flow rate area, since that of the Other refrigerant 12c, 12b and 12a sucked refrigerant also in the region of the confluence of the single suction line 22d flows through the suction line 14, so that in this area is the lowest pressure of the flowing refrigerant. Further, the common suction pipe 14 is formed with the Einzelsaugleitungen 22a to 22d so that the compressor 12a, which has the highest pressure in the lubricant sump unit 72 in the pressure cascade DK, the guide compressor, which receives from the common intake manifold 14, the largest amount of lubricant during the closest compressors 12b, 12c and 12d in the cascade direction KR receive successively less lubricant from the suction line 14, so that the last lubricant sump unit 72d receives the least amount of lubricant.

This can be achieved by virtue of the fact that the lubricant which already separates out in the common intake line 14 is for the most part the

The guide compressor 12a is supplied while the proportions of the lubricant entering the other compressors 12b, 12c and 12d from the common intake passage 14 are smaller, for which the single intake passage 22d protrudes furthest into the exit passage 14 and the single intake passages 22c, 22b and 22a successively less protrude far into the intake 14, so that in the intake 14 collecting

deposited lubricant enters primarily into the single suction line 22a.

As shown in FIGS. 5 to 7, each of the insert elements 104 comprises a housing body 122, which is provided at a first end 124 with a nozzle 126, which is connectable to the terminal 102, for example by means of a union nut 128.

In this case, an interior 132 is provided within the housing body 122, which faces from one of the terminal 102 and with the

Lubricant bath 76 communicating Schmiermittelbadöffnung 134 extends to this Schmiermittelbadöffnung 134 opposite orifices 136 and 138 of lubricant channels 142 and 144, wherein the lubricant channels 142, 144 respectively to terminals 146 and 148 for the connecting lines 114 lead. Furthermore, the interior space 132 is also provided with a lateral opening 152, which is closed by a sight glass 154 for visualizing a lubricant level of the lubricant bath 76 extending into the interior 132, so that the sight glass 154 can inspect the interior 132, preferably over its entire cross section in the vertical direction, allows.

In particular, the insert elements 104 according to the invention are connected to the respective lubricant sump unit 72 such that the orifices 136 and 138 and thus also the connections 146 and 148 in FIG

Gravity direction are arranged one above the other at a distance.

As in Figs. 8 to 11, as shown for example in FIG. 8, a small amount of lubricant introduced into the respective compressor 12 leads to a lubricant bath 76 'whose bath level indicating surface 78' is in the gravity direction below the lubricant level

Terminal 102 is located so that no lubricant can enter the interior 132 of the insert member 104.

However, if the amount of lubricant increases, then, as shown in FIG. 9, the bath surface 78 "of the lubricant bath 76" in this case the lubricant sump unit 72 "so high that in the sight glass 154 also the bath surface 78" is recognizable, the lubricant is already so high that it could enter the orifice 138 ,

As the amount of lubricant continues to increase, as shown for example in the case of the lubricant sump unit 72 "'in FIG. 10, the bath surface 78"' of the lubricant bath 76 "'is so high that it lies above the mouth opening 138 and is also clearly visible in the sight glass 154 , A further increase in the amount of lubricant, shown in Fig. 11, as shown in the case of the lubricant sump unit 72 "", the bath surface 78 "" of the lubricant bath 76 "" can also be seen in the sight glass 154 and, moreover, lubricant can enter the mouth opening 136.

Will now the mouth opening 136 of the lubricant channel 142 for

Removing lubricant from the lubricant 76 "" used, the position of the orifice 136 defines the predetermined lubricant level, from which lubricant from the lubricant bath 76 "" to the next lubricant sump unit 72 can be forwarded.

Is now as shown in Fig. 12, in the insert element 104 a the

Connecting line 114i connected to the port 146, which is associated with the first orifice 136, then lubricant enters the connection line 114i when the bath surface 78 "" over the

Mouth opening 136 is located, as shown in Fig. 11.

This lubricant then flows through the connection line 114i to the next insert element 104b, wherein the connection line 114i is connected to the connection 148 of the insert element 104b, which lies in the direction of gravity below the connection 146.

Due to the pressure cascade DK, the pressure difference causes lubricant to pass from the lubricant sump unit 72a into the lubricant sump unit 72b as long as the bath surface 78 "" is not below the mouth 136, but is always high enough to introduce lubricant into the mouth 136 and thus can also enter the connection line 114i. However, if the bath surface 78 ', 78 "and 78"', as shown for example in FIGS. 8, 9 and 10, below the mouth opening 136, so only refrigerant flows through the connecting line 114i in the lubricant sump unit 72 _b , due to the Pressure cascade DK existing pressure difference.

Since the guide compressor 72a receives the largest amount of lubricant from the suction line 14, after finite operating time of the refrigerant compressor unit, the lubricant bath 76 of the lubricant sump unit 72 will also have a bath surface 78 "" high enough for lubricants to enter the mouth opening 136 in the insert element 104b thus can be performed by the connecting line 114 ₂ to the insert element 104c, and also so that the lubricant on the

Orifice 138 enters the lubricant bath 76 of the lubricant sump unit 72c.

Even with this lubricant sump unit 72c, the lubricant bath 76 is filled up until the bath surface 78 is likewise high enough for lubricant to enter the mouth opening 136 of the insert element 104c and to be supplied to the insert element 104d by means of the lubricant line 114 ₃ .

For the sake of simplicity, the first insert element 104a and the last insert element 104d in the cascade sequence KR are each designed such that the orifice 138, the lubricant channel 144 and the connection 148 are either absent or closed, since only the orifice 136 of the latter is present , the lubricant passage 142 and the port 146 is necessary, because at the last in the cascade sequence KR last lubricant sump unit 72 d, it does not matter if the supplied lubricant via the orifice 136 or the mouth opening 138 enters the lubricant bath 76. As shown in FIG. 12, to control the individual compressors 12a, 12b, 12c and 12d of the refrigerant compressor 10, a compressor controller 162 is provided, which ensures that when switching off individual compressors 12, the remaining working compressor 12 in the

Cascade sequence KR are adjacent to each other, so that there is always the possibility of lubricant from a lying in the pressure cascade DK at a higher pressure level lubricant sump unit 72 to one in the

Cascade KR sequence nearest lubricant sump unit 72 so that the working compressors are always supplied with sufficient lubricant.

It is particularly advantageous if the compressor controller 162 operates so that when switching off individual compressors 12, the shutdown takes place in the reverse direction to the cascade direction KR, so that, for example, when a compressor shutdown of the compressor 12d is turned off and shutdown of another compressor of Compressor 12c and so on, so that the guide compressor 12a is always the last still running compressor and in the lubricant sump unit 72a of this guide compressor 12a excess lubricant is still transferred to the other next in the cascade KR following compressor 12.

Claims

P A T E N T A N S P R E C H E

Refrigeration compressor system (10) comprising at least three compressors (12) arranged in parallel between a suction line (14) and a pressure line (16), each of which has a lubricant sump unit (72),

characterized in that the compressors (12) operate in operation so that the respective pressures in the respective lubricant sump units (72) of the respective compressor (12) yield a pressure cascade (DK), according to which the compressors (12) in a defined cascade order (KR ) have stepwise slightly lower pressure in the respective lubricant sump unit (72) such that the lubricant sump units (72) are connected to a lubricant line system (112) according to the cascade order (KR) for lubricant transport, and each lubricant sump unit (72) has a port (102 ), to which an insert element (104) is connected, which on the one hand establishes a connection to the lubricant line system (112) and, on the other hand, is configured such that it engages the respective lubricant sump unit (72)

Specifies lubricant level above which a lubricant transport to the next in the cascade sequence (KR) next lubricant sump unit (72).

Refrigeration compressor system according to one of the preceding

Claims, characterized in that each insert element (104) in the direction of gravity above the respective predetermined lubricant level level port opening (136) of the lubricant line system (112) leading lubricant channel (142). Refrigeration compressor system according to one of the preceding

Claims, characterized in that the insert elements (104) in the cascade sequence (KR) between each two compressors (12) lying compressor (12) lying in the direction of gravity below the predetermined lubricant level outlet opening (138) leading to the lubricant line system (112)

Have lubricant channel (144).

Refrigeration compressor system according to one of the preceding

Claims, characterized in that the lying in the direction of gravity above the predetermined lubricant level

Mouth opening (136) and lying in the direction of gravity below the predetermined lubricant level level orifice (138) are arranged in the direction parallel to the direction of gravity at a distance from each other.

Refrigeration compressor system according to one of the preceding

Claims, characterized in that each insert element (104) comprises a visualization unit (152, 154) for visualizing the

Has lubricant level in the respective lubricant sump unit (72).

Refrigeration compressor system according to one of the preceding

Claims, characterized in that the visualization unit (152, 154) comprises a sight glass (154) adjoining a lubricant bath (76) extending into the insert element (104) of the respective lubricant sump unit (72), in which a lubricant level can be seen.

7. refrigerant compressor installation according to one of the preceding

Claims, characterized in that each insert element (104) has a visualization unit (152, 154) for visualizing a lubricant flow to a further lubricant sump unit (72).

8. refrigerant compressor system according to claim 7, characterized in that the visualization unit (152, 154) comprises a sight glass (154), which detects a lubricant flow to the lubricant line system (112).

9. refrigerant compressor system according to one of the preceding

Claims, characterized in that the lubricant line system (112) in each case in the cascade sequence (KR) successive insert elements (104) connecting connecting lines (114).

10. refrigerant compressor installation according to claim 9, characterized in that the connecting line (114) each one, the mouth opening (136, 138) having lubricant channel (142, 144) of an insert element (104) with one, one of the mouth openings (136, 138 ) having lubricant channel (142, 144) of the other insert element (104) connects.

11. Refrigerant compressor system according to one of the preceding

Claims, characterized in that the connecting line (114) has a connection between the lubricant passage (142) with an outlet opening (136) lying in the direction of gravity above the predetermined level of lubricant level and the lubricant channel (144) with a gravitational direction under the

respective given lubricant level lying

Mouth opening (138) produces.

12. refrigerant compressor installation according to one of the preceding

Claims, characterized in that the pressure level in the respective lubricant sump unit (72) of the respective compressor (12) is determined by the formation of the suction line system (14, 22).

13. refrigerant compressor system according to one of the preceding

Claims, characterized in that the compressors (12) are formed so that the pressure in the respective lubricant sump unit (72) with the suction pressure of the respective compressor (12) is correlated.

14. Refrigerant compressor installation according to claim 13, characterized in that the pressure in the respective lubricant sump unit (72) corresponds to the suction pressure of the respective compressor (12).

15. refrigerant compressor system according to one of the preceding

Claims, characterized in that the connection (102), with which the insert element (104) is connected, is a standard connection (102) for a sight glass for detecting the lubricant level.

16. refrigerant compressor system according to one of the preceding

Claims, characterized in that the Ansaugleitungssystem (14, 22) is designed so that in the cascade order (KR) first compressor (12) from the intake manifold (14, 22) is supplied with the largest amount of lubricant.

17 refrigerant compressor system according to claim 16, characterized in that the suction line (14, 22) is formed so that in the cascade order (KR) on the first compressor (12a) following compressor (12) smaller amounts of lubricant from the intake manifold (14, 22).

18. refrigerant compressor system according to claim 17, characterized in that the suction line (14, 22) is formed so that in the cascade sequence (KR) successive compressor (12) in accordance with their position in the cascade sequence (KR) respectively lower amounts of lubricant from the Suction line system (14, 22) obtained.

Refrigeration compressor system according to one of the preceding

Claims, characterized in that it has a control (162) for the individual compressors (12), which ensures the shutdown of individual compressors (12) that the still working compressor (12) always arranged side by side in the cascade sequence (KR) are.