WO2014131587A1 - Refrigerant compressor system - Google Patents

Abstract

The invention relates to a refrigerant compressor system, comprising at least one low-pressure stage and at least one high-pressure stage, a suction duct leading from a suction connection for the refrigerant to the low-pressure stage, an intermediate-pressure duct leading from the low-pressure stage to the high-pressure stage, a high-pressure connection connected to the high-pressure stage, and a lubricant bath to which the intermediate pressure is applied in the intermediate-pressure duct. In order to improve such a refrigerant compressor system in such a way that an adequate lubricant supply for the low-pressure stage is always ensured, it is proposed that a lubricant-feeding device draws lubricant from the lubricant reservoir and feeds said lubricant to the suctioned refrigerant flowing to the low-pressure stage in a suctioning path.

Description

 REFRIGERANT COMPRESSOR SYSTEM

The invention relates to a refrigerant compressor system comprising at least one low pressure stage and at least one high pressure stage, a leading from a suction port for the refrigerant to the low pressure stage suction channel leading from the low pressure stage to the high pressure stage intermediate pressure channel, connected to the high pressure stage high pressure port and a with the Intermediate pressure in the intermediate pressure channel acted upon lubricant bath.

Such refrigerant compressor systems are known from the prior art.

In these, the problem has emerged that in the low-pressure stage, especially with valves of the same, damage occurs because at least in some operating conditions not enough lubricant is available.

The invention is therefore based on the object to improve a refrigerant compressor plant of the generic type such that always a sufficient supply of lubricant for the low-pressure stage is guaranteed.

This object is achieved according to the invention in a refrigerant compressor system of the type described above in that a lubricant supply device removes lubricant from the lubricant reservoir and supplies the sucked refrigerant flowing to the low-pressure stage.

The advantage of the solution according to the invention is the fact that with the lubricant supply device according to the invention, it is possible to exploit the pressure gradient between the intermediate pressure and the suction pressure of the refrigerant compressor system and thus lubricant from the Supply lubricant reservoir of the sucked refrigerant of the low-pressure stage and thereby ensure adequate lubrication, in particular of valves of the low-pressure stage.

Basically, the supply of lubricant at any point would be conceivable as long as the supply is made to the sucked refrigerant.

However, in order to supply the lubricant as low as possible to the low-pressure stage, it is preferably provided that the lubricant feeds the lubricant to an intake path of the low-pressure stage, in particular a suction channel and / or a suction chamber of the low-pressure stage, so that the supply of the lubricant without outside of the equipment housing can be realized to be provided components.

In particular, the suction channel or the suction chamber are in the

Conditioning case.

In order not to let the amount of the lubricant supplied to the lubricant be too large, but always to keep within reasonable limits, it is preferably provided that the lubricant supply means comprises a metering unit, which metering a lubricant quantity operating state-dependent, so that with the metering unit Possibility exists to adjust the lubricant quantity depending on operating conditions.

For example, it is provided to define different operating states and / or operating state regions and to meter the lubricant quantity with the dosing unit depending on the operating state and / or operating state region. With regard to the metering in the individual operating states, it is favorable if, during a compressor standstill, the supply of lubricant is stopped by the metering unit, in order thus to avoid an accumulation of lubricant in the intake path.

Furthermore, it is advantageous if, during or after a compressor standstill, the metering unit prevents pressure equalization between the starting path and the lubricant bath via the lubricant supply device.

As a result, it is possible, due to the pressure difference maintained in the intake path, to recirculate in this collecting lubricant via leakage paths, for example in the region of the respective pressure stages, into the lubricant bath and thus avoid oil shocks, in particular in the area of the working valves, when the refrigerant compressor system is restarted.

The operating conditions dependent dosage could be done via a separate control provided for this purpose.

Another more advantageous solution provides that the metering unit is compressor-power-controlled, so that it is possible to detect the operating conditions by means of the compressor power and to meter the lubricant quantity in accordance with the compressor power.

In principle, the dosing unit could be designed in many different ways.

For example, the metering unit could be controlled in many different ways depending on the compressor capacity.

For example, it would be possible to control the compressor power by controlling a drive motor for the refrigerant compressor system and to electronically control the dosing unit according to the control of the drive motor with this control. However, a particularly simple solution provides that the metering unit is controlled by a compressor shaft and according to the speed of the

Compressor shaft dosed the amount of lubricant.

With regard to the design of the metering unit itself, no further details were given.

For example, the dosing unit could be designed as a slide or valve.

A particularly simple solution provides that the dosing unit as

Metering pump is formed.

With such a metering pump is in a simple way the ability to make a performance-dependent dosage.

In particular, the metering pump is preferably designed so that it has a speed-dependent delivery volume.

This is particularly easy to achieve when the metering pump is controlled by the compressor shaft, in particular driven.

With regard to the metering pump itself, no details have yet been given.

Thus, an advantageous solution that the metering pump a

Gear pump is.

With regard to the lubricant mass flow supplied to the sucked-in refrigerant, it is preferably provided that it does not become too large, since otherwise the compressor output and / or the stability of the compressor Refrigerant compressor system is impaired, for example, an oil compression in the work spaces leads to an increased drive load.

For this reason, it is preferably provided that a lubricant mass flow supplied to the drawn-in refrigerant amounts to a maximum of 5% of the total mass flow of refrigerant and lubricant drawn in by the low-pressure stage.

With regard to the arrangement of the dosing unit so far no further details have been made.

Thus, it is preferably provided that the refrigerant compressor installation has a contact housing, on which the dosing unit is arranged.

Preferably, the metering unit is arranged in a cover of the contact housing, since it can be installed in a simple manner in the investment housing, in particular, the metering unit is integrated in the lid.

To be able to form the lubricant supply device as simply and as protected as possible, a delivery channel leading from the dosing unit to the lubricant reservoir is provided on the system housing, preferably on the cover, in particular in the system housing, preferably in the cover, through which there is the possibility of the lubricant to promote from the lubricant reservoir to the metering unit.

Furthermore, it is expedient if, at the plant housing, in particular in the plant housing, a leading from the metering unit to the intake path conveying channel for the lubricant is provided, so that thereby a simple production and assembly is possible.

The delivery channel can thereby run exclusively in the system housing, for example in a cover thereof. But there is also the possibility that the delivery channel partially in

Plant housing and partially runs in a compressor component, for example in a compressor shaft.

In the latter case, a targeted lubrication of bearings for the compressor shaft can preferably also take place by means of the delivery channel.

In particular, it is favorable for supplying the lubricant to the sucked refrigerant flow when the intake path is associated with a nozzle for the lubricant to be supplied thereto.

With regard to the type of compression of the refrigerant in the refrigerant compressor system, no further details have been given in connection with the previous embodiments.

Thus, it would be conceivable in principle to provide any type of compressor, for example scroll compressors or screw compressors.

However, the solution according to the invention has particular advantages when the refrigerant compressor comprises a reciprocating piston compressor, since a reciprocating piston compressor has intake valves which are particularly susceptible to wear.

Furthermore, it has proven to be advantageous in the formation of a low-pressure stage and a high pressure stage when the piston compressor to form the low pressure stage comprises a first cylinder bank and the formation of the high-pressure stage a second cylinder bank, so that both the low-pressure stage and the high-pressure stage can be easily separated in that they are formed by different cylinder banks of a compressor.

Furthermore, no details have been given as regards the arrangement of the lubricant reservoir.

For example, the lubricant reservoir could be an external reservoir. However, a particularly simple solution provides that the lubricant reservoir is arranged in a drive space of the system housing, wherein the drive for the low pressure stage and the high pressure stage is arranged in the drive space.

In particular, it is provided that the lubricant reservoir is arranged on the bottom side of the drive space.

Further features and advantages of the invention 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;

Fig. 2 is a view of the refrigerant compressor plant in the direction of

 Arrow A in Fig. 1;

Fig. 3 is a section along line 3-3 in Fig. 2;

Fig. 4 is a section along line 4-4 in Fig. 3;

Fig. 5 is a section along line 5-5 in Fig. 2;

Fig. 6 is a section along line 6-6 in Fig. 2;

Fig. 7 is a section along line 7-7 in Fig. 6 with partial

Representation of the cylinder head, the valve plate and the cylinder liners of a cylinder bank; Fig. 8 is an enlarged view of the section in Fig. 6 in

 Area of the valve plate and the intake valve;

9 is a plan view in the direction of the arrow A in FIG. 3;

10 is a section along line 10-10 in FIG. 9;

Fig. 11 is a view corresponding to FIG. 9 with a plan view of a

 Dosing pump according to the first embodiment;

FIG. 12 shows a longitudinal section similar to FIG. 3 through a second exemplary embodiment of a refrigerant compressor system according to the invention and FIG.

13 shows a section similar to FIG. 10 through the second exemplary embodiment of the refrigerant compressor installation according to the invention.

An exemplary embodiment of a refrigeration compressor system 10 shown in FIGS. 1 and 2 comprises a system housing designated as a whole by 12, which extends in a longitudinal direction 14.

The plant housing 12 in this case comprises a central housing body 16, which also extends in the longitudinal direction 14 and on a first end face a first end cover 22 and on a second end side a second end cover 24 carries, which, for example, still facing away from the central housing body 16 Side is still provided with a flange 26 for mounting an inverter.

The central housing body 16 comprises, as shown in FIG. 3, a

Drive housing portion 32 of a reciprocating compressor 40, which encloses a drive space 34, wherein the drive space 34 between the first end cover 22 and an intermediate wall 36 of the central housing body 16 extends, which lies between the drive housing portion 32 and a motor housing portion 42 of the central housing body 16.

The motor housing section 42 for accommodating an electric motor 50 comprises an engine compartment 44, which in turn lies between the intermediate wall 36 and the second end cover 24, the engine compartment 44 also extending from the motor housing section 42 into the second end cover 24.

In the engine compartment 44 of the designated as a whole with 50 electric motor, which includes a stator 52 arranged in the engine compartment 52 and a rotor 52 enclosed by the stator 52, wherein the rotor 54 is rotatable about a rotation axis 56.

For this purpose, the rotor 54 is seated on a designated as a whole by 60 compressor shaft of the reciprocating compressor 40, which carries with a extending in the engine compartment 44 rotor support portion 62, the rotor 54 and rotatably supports this about the axis of rotation 56. The compressor shaft 60, however, also extends into the drive space 34 and has a drive section 34 passing through the drive section 64 which carries a plurality of eccentric 66.

The compressor shaft 60 is in turn mounted in the system housing 12 in a provided on the intermediate wall 36 bearing receptacle 72 and provided on the first end cover 22 bearing receptacle 74 so that the drive portion 64 is located with the eccentrics 66 between the bearing receivers 72 and 74, while the rotor carrier portion 62 extends from the bearing receiver 72 with a free end in the engine compartment 44.

As shown in Fig. 3, the drive portion 64 of the compressor shaft 60 is used with its eccentrics 66 for driving a plurality of cylinders 82 of the reciprocating compressor 40, which are arranged for example in the form of two cylinder banks 84 and 86 in the drive housing portion 32, wherein each of the cylinder 82nd a cylinder chamber 92, in which a piston 94 is movable in a stroke direction 96, wherein, for example, each cylinder chamber 92 is enclosed by a seated in the drive section cylinder liner 98.

Each piston 94 is in turn driven by a connecting rod 102, which is articulated on the one hand on the piston 94 and on the other hand, one of the eccentric 66 encloses.

The cylinder chambers 92 of each of the cylinder banks 84 and 86 are closed by a valve plate 104 and 106, wherein the respective valve plate 104 and 106 on its side facing away from the respective cylinder liner 98 carries a cylinder head 112 and 114, respectively.

The cylinder head 112 is associated with the first cylinder bank 84, and the cylinder head 114 is associated with the second cylinder bank 86.

For example, each of the valve plates 104, 106 and each of the cylinder heads 112 and 114 engage over all of the cylinder chambers 92 of the cylinders 82 of the respective cylinder bank 84, 86, respectively.

In the refrigerant compressor system 10 according to the invention, as shown in FIG. 1 and 5, for example, a Saugabsperrventil 122 is provided, which in turn is provided with a suction port 124 and which is for example mounted on the first end-side cover 22 and zuzusaugendes refrigerant to a provided in the first end cover 22 and the drive housing portion 32 suction channel 126, which extends from the Saugabsperrventil 122 to the first cylinder bank 84, wherein the suction passage 126 passes through an opening 128 in the drive housing portion 32 which is aligned with an opening 132 in the valve plate 104, so that the sucked refrigerant leak from the drive housing portion 32, the valve plate 104 and can enter into a suction chamber 134 of the cylinder head 112, as shown in FIGS. 3, 6 and 7 are shown. In particular, the suction channel 126 and the suction chamber 134 form a suction path 130 for the sucked refrigerant provided in the plant housing 12.

Instead of Saugabsperrventils 122 but can also be a simple suction line connection, be it provided by a screw or a joint connection.

The suction chamber 134 is located on a side facing away from the cylinder chamber 92 of the respective valve plate 104, 106 and arranged in the respective valve plate 104, 106 suction openings 136 for all cylinders 82 of the respective cylinder bank 84, 86, wherein on a cylinder space 92 side facing each suction port 136 is associated with a working valve or suction valve 138, which is arranged for example on the valve plate 104 and which comprises a suction lamella or valve tongue 140, which in the in Fig. In FIG. 7 and 8 drawn solid, closed and applied to the valve plate 104 position, the suction port 136 closes and in a in Fig. In FIG. 7 and 8 dashed open position, the suction port 136 releases, so that can be sucked through this refrigerant into the cylinder chamber 92.

To determine the mobility of the valve tongue 140 is used on the one hand in the closed position, the valve plate 104 and on the other hand, for example, in a Zylinderbüchsenkragen 144 of the cylinder liner 98, a guide recess 142 is provided, in which the respective valve tongue 140 engages with a tongue tip 146, so that the tongue tip 146 in the

Guide recess 142 in their movements between their

closed and its open position.

Laying down the maximum open position of the valve tongue 140, the guide recess 142 is provided with a particular in FIG. 8 illustrated stop surface 148 provided which the maximum open position, the means the maximum position of the valve plate 104, the valve tongue 140 sets so that the guide recess 142 forms with the stop surface 148 a Hubfänger.

In the respective cylinder head, in Fig. 7 and 8 the cylinder head 112, the suction chamber 134 is also associated with a pressure chamber 152, which is also formed in the cylinder head 112, wherein in the pressure chamber 152 a number of example, sitting on the valve plate 104 exhaust valves 154 is arranged, which also in the Able to release outlet openings so that compressed refrigerant from the cylinder chamber 92 can enter the pressure chamber 152.

In the same way as the cylinders 82 of the cylinder bank 84 with the valve plate 104 and 106 and the cylinder 82 of the cylinder bank 86 are formed, in particular, the valve plate 106 and the cylinder head 114 are formed accordingly.

As in particular in FIG. 4 and 5, the refrigerant compressor system operates with the two cylinder banks 84 and 86 as a two-stage compressor, that is, of the low pressure stage 156 forming cylinders 82 of the first cylinder bank 84 at suction pressure PS drawn refrigerant is first compressed to an intermediate pressure PZ, then in flows through the engine compartment 44, flows through the engine compartment 44 and enters from this in an intermediate pressure channel 162 of the drive housing portion 32, so that the intermediate pressure PZ refrigerant can enter the suction chamber 134 of the cylinder head 114 of the cylinder bank 86 and of the high-pressure stage 158 forming cylinders 82nd the second cylinder bank 86 is ultimately compressed to high pressure PH, wherein the standing at high pressure PH refrigerant can then escape from the high pressure port 164.

In order to avoid damage to the suction valves 138, which manifest themselves, for example, in that the valve tongues 140, in particular in the region of their tongue tips 146, show breaks over time due to impact The valve tongues 140 and / or the tongue tip 146 at least partially formed on the valve plate 104 and / or the stop surfaces 148, a designated as a whole 170 lubricant supply means is provided, which consists of a over a bottom portion 172 of the drive chamber 34 forming lubricant bath 174 by means of a For example, in the first front-side cover 22 provided first conveyor channel 176 and a filter upstream of this 178 takes lubricant and this via the conveyor channel 176 a metering unit 180 feeds (Fig. 3 and 9 to 11).

From the dosing unit 180, the lubricant via a in FIG. 6 and Fig. 9 to 11 shown and provided in the first end-side cover 22 second delivery channel 182 and a still arranged in this filter 184 a directed into the suction channel 126 nozzle 186 supplies, with which the lubricant injected into the sucked by suction refrigerant suction passage 126 so that the lubricant injected into the suction passage 126 is entrained by the sucked refrigerant and supplied to at least the suction valves 138 for lubrication thereof.

The pressure difference for conveying the lubricant through the lubricant supply device 170 is already present in that in the drive chamber 34 a pressure corresponding to the intermediate pressure PZ is present, which is higher than the suction pressure PS, so that this pressure difference already for conveying the lubricant from the lubricant 174 is sufficient to the nozzle 186.

The dosing unit 180 thus does not necessarily have to produce a pressure difference, but serves primarily to achieve a dosing of the lubricant as a function of a power of the refrigerant compressor system, in the simplest case depending on a rotational speed of the compressor shaft 60.

This supplied lubricant forms, in particular in the region of the valve plate 104 and the abutment surfaces 148 of the guide recesses 142, a lubricant support, by which a striking of the valve tongues 140 and the tongue tips 146 of the valve tongues 140 on the valve plate 104 and / or on the abutment surfaces 148 is damped, so as to avoid breakouts in the region of the tongue tips 146 and / or the valve tongues 140.

The dosing unit 180 could be a quantity-controlling valve in order to make it as simple as possible.

In particular, the metering unit 180 is designed as a metering pump 190 with a speed-dependent, in particular speed-proportional delivery volume, which is coupled to the compressor shaft 60 and thus driven synchronously with the compressor shaft 60 to the dosage of injected via the nozzle 148 in the suction passage 126 lubricant proportional to Speed of the compressor shaft 60 to make.

As shown in FIG. 11, the metering pump 190 is designed as a gear pump, which has an internally toothed outer body 192 and a corresponding externally toothed inner body 194 which is rotatable on the one hand about an axis 196 of an eccentric pin 198, wherein the eccentric pin is in turn arranged eccentrically to the axis of rotation 56 of the compressor shaft 60 and is formed on the compressor shaft 60, so that a drive of the inner body 194 of the gear pump 190 takes place directly through the compressor shaft 60.

In this case, the outer body 192 and the inner body 194 are formed relative to each other, that form by the eccentric rotation of the eccentric pin 198 between the outer body 192 and the inner body 194 free spaces 202, which by the eccentric movement of the eccentric pin 198 about the axis of rotation 56 of the compressor shaft 60 revolving be moved so that through an inlet pocket 204 through the conveying channel 176 supplied lubricant enters the forming free spaces 202 and through the Movement of the free spaces 202 is conveyed about the rotation axis 56 to an outlet pocket 206 which is connected to the delivery channel 182, so that through this the lubricant of the nozzle 186 directed into the suction channel 126 can be supplied.

The gear pump 190 is constructed so that it no longer blocked around the rotation axis 56 around moving eccentric 198 and thus stationary inner body 194 lubricant delivery through the lubricant supply means 170 and thus blocked at idle compressor shaft 60, a supply of lubricant to the suction channel 126.

This has the advantage that at a standstill of the drive of the compressor shaft 60 and thus at a standstill of the piston 94 no lubricant from the lubricant bath 174 can flow into the suction channel 126, since the metering pump 190 prevents this.

Furthermore, the metering pump 190 also blocks a reduction in the pressure in the suction channel 126 with the compressor shaft 60 stationary and thus stationary inner body 194, so that lubricant still present in the suction channel 126 via other paths, such as leaks in the piston 94 of the cylinder banks 84, 86 for lubricant bath 174 flows back.

This also has the advantage that it is possible to prevent flooding of the suction channel 126 with lubricant at a standstill of the refrigerant compressor system according to the invention and also to maintain the pressure in the suction channel 126 to the lubricant in the suction channel 126 via leaks, for example in the Cylinder banks 84, 86 supply the lubricant bath 104 again and thus to avoid oil shocks when restarting the refrigerant compressor system.

In the first exemplary embodiment of the solution according to the invention, the lubricant supply device 170 is integrated in the first end-side cover 22, so that in particular the delivery channel 176 and the delivery channel 182 lie with the nozzle 184 in the first end-side cover 22 and preferably also the filters 178 and 184 also in the first end-side cover 22 sit.

In addition, advantageously, the first cover 22 also includes a receptacle 212 for the outer body 192 of the metering pump 190, wherein in this receptacle 212 and the inlet pocket 204 and the outlet pocket 206 frontally, in particular between the bearing receptacle 74 and the receptacle 212 open.

In the receptacle 212, the outer body 192 can be used rotationally and in this then sits the inner body 194, which is rotatably mounted on the eccentric pin 198 in the manner described about the axis 196 and thus rotates with the eccentric pin 198 about the axis of rotation 56.

In a second embodiment of a refrigerant compressor system according to the invention, shown in FIGS. 12 and 13 are those features which are identical to those of the first embodiment, provided with the same reference numerals, so that in this respect also the contents of the statements to the first embodiment can be made in full.

In particular, the lubricant bath 174 is provided in the same manner as in the first embodiment in the drive space 34, from which the lubricant supply means 170 'removes lubricant and also through the provided in the first end cover 22 conveying channel 176th

Further, also in the same manner as in the first embodiment in the first end-side cover 22, the metering unit 180, formed by the metering pump 190, is provided and formed in the same manner as described in connection with the first embodiment. However, the metering pump 190 does not deliver the lubricant into a further extending in the first end cover 22 conveyor channel, but in a preferably coaxial with the axis of rotation 56 in the compressor shaft 60 'extending compressor shaft passage 222, wherein of the compressor shaft passage 222 in the bearing receptacle 72' in the partition 36 'a transverse channel 224 to a provided in the bearing receptacle 72 to the compressor shaft 60' circumferential receiving groove 226 leads, of which in turn a delivery channel 228 in the intermediate wall 36 'and in the drive housing portion 32' up to a nozzle 232 which extends into the suction channel 126 'in the drive housing section 32' opens.

Further, the compressor shaft channel 222 is provided with further transverse channels, for example, a transverse channel 242 for lubricating a sliding bearing 244 between the compressor shaft 60 'and the bearing receptacle 74 serves transverse channels 246 for lubricating slide bearings 248 between the eccentrics 66 and the connecting rods 102 serve and transverse channels 252 for lubricating slide bearings 254 between the compressor shaft 60 'and the bearing seat 72' serve.

Thus, the lubricant supply device 170 'according to the invention serves not only to supply lubricant to the suction channel 126', in order to supply the lubricant in the

To achieve effects described in connection with the first embodiment in the region of the suction valves 138, but also to provide bearings 244, 248, 254 in the region of the compressor shaft 60 'with lubricant.

In the second embodiment, apart from the lubrication of the various plain bearings, the same advantages are achieved as described in detail in connection with the first embodiment.

Claims

claims Comprising 1. refrigerant compressor system  at least one low-pressure stage (156) and at least one high-pressure stage (158), a suction channel (126) leading from a suction connection (124) for the refrigerant to the low-pressure stage (156), one from the low-pressure stage (156) to the high-pressure stage (158) leading intermediate pressure channel (162), a high-pressure connection (164) connected to the high-pressure stage (158) and a lubricant bath (174) charged with the intermediate pressure (PZ) in the intermediate pressure channel (162),  That is, a lubricant supply means (170) extracts lubricant from the lubricant reservoir (174) and supplies it to the sucked refrigerant flowing to the low pressure stage (156) in an intake path (130). 2. Refrigerant compressor according to claim 1, characterized in that the lubricant supply means (170), the lubricant in the system housing (12) extending suction path (130) of the low-pressure stage (156) supplies. 3. Refrigerant compressor installation according to one of the preceding claims, characterized in that the lubricant supply means (170) comprises a metering unit (180), which doses a lubricant quantity operating state-dependent. 4. refrigerant compressor system according to claim 3, characterized in that the metering unit (180) is compressor power controlled. 5. refrigerant compressor system according to claim 1, characterized in that the metering unit (180) by a compressor shaft (60) is controlled. 6. refrigerant compressor installation according to one of the preceding claims, characterized in that the metering unit (180) is designed as a metering pump (190). 7. refrigerant compressor installation according to claim 6, characterized in that the metering pump (190) has a speed-dependent delivery volume. 8. refrigerant compressor system according to claim 6 or 7, characterized in that the metering pump (190) is a gear pump. 9. Refrigerant compressor installation according to one of the preceding claims, characterized in that a lubricant mass flow supplied to the sucked-in refrigerant amounts to a maximum of 5% of the total mass flow of refrigerant with lubricant drawn in by the low stage (156). 10. Refrigerant compressor installation according to one of the preceding claims, characterized in that the refrigerant compressor installation has a system housing (12) on which the dosing unit (180) is arranged. 11. refrigerant compressor system according to claim 10, characterized in that the dosing unit (180) on a cover (22) of the plant housing (12) is arranged. 12. refrigerant compressor system according to claim 11, characterized in that the dosing unit (180) in the lid (22) is integrated. 13. refrigerant compressor system according to claim 11 or 12, characterized in that on the plant housing (12) from the metering unit (180) to the lubricant reservoir (174) leading conveying channel (176) is provided. 14. Refrigerant compressor system according to one of claims 11 to 13,  characterized in that on the plant housing (12) from the metering unit (180) to the intake path (130) leading conveying channel (182, 228) is provided for lubricant. 15. Refrigerant compressor system according to one of the preceding claims, characterized in that the suction path (130) is associated with a nozzle (184, 232) for the lubricant to be supplied thereto. 16. Refrigerant compressor system according to one of the preceding claims, characterized in that the refrigerant compressor unit (10) comprises a piston compressor (40). 17. refrigerant compressor system according to claim 16, characterized in that the piston compressor (40) for forming the low pressure stage (156) comprises a first cylinder bank (84) and for forming the high-pressure stage (158) comprises a second cylinder bank (86). 18. Refrigerant compressor installation according to one of the preceding claims, characterized in that the lubricant reservoir (174) in a drive space (34) of the plant housing (12) is arranged. 19. Refrigerant compressor installation according to claim 18, characterized in that the lubricant reservoir (174) is arranged on the bottom side of the drive space (34).