CN102017827B

CN102017827B - Cooling plate for a frequency converter and compressor using said cooling plate

Info

Publication number: CN102017827B
Application number: CN200980116492.8A
Authority: CN
Inventors: 詹尼·坎迪奥
Original assignee: Refcomp SpA
Current assignee: Fujian Snowman Co Ltd
Priority date: 2008-05-09
Filing date: 2009-05-08
Publication date: 2013-08-07
Anticipated expiration: 2029-05-08
Also published as: EP2286646A1; ITVI20080106A1; CN102017827A; WO2009136277A1

Abstract

The invention concerns a cooling plate (6; 30) for a frequency converter (4), comprising a surface (6a) suited for coupling with the frequency converter (4) and a duct assembly (10) which defines an outflow direction (V) of the cooling fluid and comprises a first group of pipes (12) and a second group of pipes (13). The second group of pipes (13) is arranged at the downstream of the first group of pipes (12), and an overall flow cross section of the second group of pipes (13) is larger than that of the first group of pipes (12). Each pipe in the first group of pipes (12) is connected to corresponding pipe in the second group of pipes (13). The second group of pipes is arranged between the first group of pipes (12) and the frequency converter (4). Moreover, the invention also relates to a compressor including the above cooling plate.

Description

Be used for the coldplate of frequency converter and the compressor that comprises described coldplate

Technical field

The present invention relates to a kind of coldplate of connecting with frequency converter of being particularly suitable for.

The invention still further relates to a kind of by the frequency converter feeding and be equipped with the compressor of above-mentioned plate for cooling transducer itself.

Background technology

As known, frequency converter is the feasible electronic equipment that can control the electro-motor revolution.

Transducer is through for example being usually used in that the motor of motor-mount pump or compressor is carried out feeding, thereby can make its performance be adapted to user's needs.Therefore be known that equally frequency converter produces a certain amount of heat in its operating process, and must suitably cool off it, in order to avoid fault and any possible damage that its electronic unit is caused.

According to known technology, above-mentioned cooling effect obtains with the hottest contacted heat dissipation element of electronic unit of transducer by means of being arranged to, described heat dissipation element absorbs heat from the hottest electronic unit of described transducer, thereby transfers heat to heat dissipation element contacted cooling fluid with it.

Under the situation of compressor, especially in cooling system and similar system under the situation of used positive displacement compressor, heat dissipation element is often by cooling off at cooling system and the same fluid that flows in compressor itself.

According to known structural form, above-mentioned heat dissipation element is the coil pipe with homogeneous diameter, described cooling fluid in described coil pipe, circulate and described coiled tube arrangements for to contact with the thermal part of transducer.

According to structural change, set up heating panel, described heating panel places between coil pipe and the transducer, thereby increases the heat exchange surface between the two elements.

Above-mentioned modification is for the transducer that for example is associated with cooling system.

In this case, the cooling fluid that circulates in cooling system also is used for the cooling heat dissipation element.

Cooling fluid is drawn out of and is transferred to the coil pipe of heat dissipation element in the downstream of condenser under liquid condition, cooling fluid evaporates along the coil pipe of described heat dissipation element, thereby from the transducer heat extraction.

Above-mentioned evaporation allows more effectively heat extraction, the feasible overall size that can reduce needed total fluid flow rate and coil pipe.

Yet above-mentioned known disc pipe has limited heat exchange efficiency, and must take corresponding high cooling fluid flow rate away from cooling system.

This high flow rate causes that the gross efficiency to cooling system causes the shortcoming of adverse effect.

And because the diameter of coil pipe must be proportional with flow rate, therefore have another shortcoming: high flow rate causes the overall size of coil pipe own to increase.

The overall size of transducer and relevant heat dissipation element has produced another shortcoming: its make be difficult to be unkitted be furnished with this equipment have mounting converter in the system.

Document US 2005/276014 A1 discloses a kind of heat management device, described heat management device comprises channel design, some cooling ducts of arranged in series are launched and be provided with to described channel design in the plane, thereby allow to remove different hot-fluids from the respective regions of semiconductor packages.

File WO 2008/010851 A discloses a kind of heat abstractor, and described heat abstractor comprises the fluid passage, and described fluid passage is configured to change the speed of cooling agent, thereby the temperature of the length of compensation refrigerant longshore current body passage raises.

Summary of the invention

The objective of the invention is to overcome the exemplary shortcomings of all above-mentioned prior aries.

Especially, first purpose of the present invention is to realize a kind of coldplate for frequency converter, and the efficient of described coldplate is higher than the efficient of the known heat dissipation element that is suitable for similar purpose.

The present invention also aims to construct the compressor with frequency converter, the overall size of described compressor can be equivalent to not have the overall size of the compressor of transducer, and under any circumstance all less than the overall size of the compressor with transducer of known type.

Above-mentioned purpose realizes by a kind of coldplate for frequency converter according to the present invention.Described coldplate comprises surface and conduit assembly, described surface is suitable for connecting with described frequency converter, described conduit assembly is arranged between entrance opening and the exit opening, and described entrance opening and described exit opening limit cooling fluid along the outflow direction of described conduit assembly.Described conduit assembly comprises a plurality of rectilinear duct that are arranged side by side, and each described rectilinear duct has uniform cross section.Described rectilinear duct comprises first group of pipeline and second group of pipeline, and described second group of pipeline is arranged in the downstream of described first group of pipeline according to described outflow direction.Total flow cross section of described second group of pipeline is greater than total flow cross section of described first group of pipeline.First end of described first group of ducted each pipeline is connected in first end of described second group of ducted corresponding pipeline by corresponding first connecting tube.Described second group of pipeline is included between described first group of pipeline and the described frequency converter.

In this coldplate, preferably, described coldplate comprises second head, and described second head is associated with second side of described single block and is provided with the 3rd connecting tube, and described the 3rd connecting tube is suitable for connecting the opening of described the 3rd blind hole.

Same purpose also realizes by a kind of compressor according to the present invention.Described compressor comprises housing, and described housing holds electro-motor, and described electro-motor is by the frequency converter feeding and functionally be connected in compression set for compression working fluid.Described compressor comprises aforesaid coldplate, and the contact surface of described coldplate and described frequency converter are arranged in contact.

In this compressor, preferably, described compressor comprises choke valve, and described choke valve functionally is connected in the described entrance opening of described coldplate.

Advantageously, be that the efficient of increase of the plate of theme of the present invention makes the heat dissipation element can compare the known type that can remove identical hot-fluid use lower cooling fluid flow rate, thereby improve the gross efficiency of system.

And advantageously, needed more low fluid flow rates makes other heat dissipation element that can compare the known type with identical heat-sinking capability reduce the size of plate of the present invention.

Therefore, advantageously, be that the coldplate of theme of the present invention is enough compact being integrated in the compressor with transducer, thereby further reduce the overall size of assembly.

Also advantageously, above-mentioned integrated making can reduce the complexity that compressor is inserted in system wherein.

Compact size provides another advantage: compressor of the present invention can be used in the existing system and replaces not having the compressor of converter, and need not system is carried out major change.

Description of drawings

In the explanation to preferred implementation of the present invention and modification thereof that the reference accompanying drawing provides by non-limiting example, show described purpose, advantage and the other side that will emphasize in more detail hereinafter, in described accompanying drawing:

Fig. 1 shows the three-dimensional partial section of the compressor that is theme of the present invention;

Fig. 2 shows the stereogram of the coldplate that is theme of the present invention;

Fig. 3 shows the stereogram of details of the coldplate that is theme of the present invention;

Fig. 4 is the partial view along the cross section of coldplate among Fig. 2 of planar I V-IV intercepting;

Fig. 5 is the end view along the cross section of coldplate among Fig. 2 of plane V-V intercepting;

Fig. 6 shows the vertical view of the coldplate shown in Fig. 2;

Fig. 7 shows the stereogram of structural change of the coldplate that is theme of the present invention.

Embodiment

The compressor that is theme of the present invention is shown among Fig. 1, and the integral body of compressor described in the figure is by 1 expression.

Compressor 1 comprises housing 2, and described housing 2 holds the electro-motor 3 by frequency converter 4 feedings.

Electro-motor 3 functionally is connected in compression set 5, and described compression set 5 preferably but not necessarily comprise a pair of counter-rotating screw rod.

Described screw rod defines a plurality of chamber 5a, and each described chamber 5a is provided with ingress path and transport path, treats compressed working fluid thereby hold.

As known, screw rod is constructed such that: in its rotation process, the volume of chamber 5a reduces, thus compression working fluid.

Especially at refrigerating field, above-mentioned helical-lobe compressor 1 itself is known and is general.

But, clearly, as long as be equipped with the motor by frequency converter 4 feedings, then the present invention can be applied to the compressor 1 of any other known type, for example compressor of positive-displacement compressor, reciprocating compressor, blade-type blower, centrifugal compressor or any other type.

Compressor 1 comprises coldplate 6, and described coldplate 6 is provided with and frequency converter 4 contacted contact surface 6a, and described contact surface 6a preferably is in the site of the sensitiveest electronic unit of the heat that produces maximum.

Plate 6 comprises the conduit assembly 10 for cooling fluid, described cooling fluid preferably but not necessarily be in compressor 1 circulation identical working fluid.

Especially when compressor 1 was included in the cooling circuit, this back one condition was favourable, because the working fluid in loop is particularly suitable for from plate 6 heat extractions in this case.

In fact, above-mentioned fluid has low temperature, and, can utilize it to evaporate to obtain effective cooling of plate 6.

As shown in Figure 2, above-mentioned conduit assembly 10 launches between entrance opening 7 and exit opening 8, thereby defines cooling fluid along the outflow direction V of conduit assembly 10.

Obviously, follow the track that more or less becomes curve that itself is limited by conduit assembly 10, above-mentioned outflow direction V can take along the different directions of conduit assembly 10.

According to the present invention, the surface area longshore current outgoing direction V of the cross section of conduit assembly 10 increases.

The surface area of the cross section of conduit assembly 10 preferably longshore current outgoing direction V increases with centrifugal pump.

More accurately, and illustrate in greater detail ground as Fig. 3 to Fig. 6, conduit assembly 10 comprises and is arranged as side by side and preferably is arranged as parallel a plurality of rectilinear duct 11 that each in the described rectilinear duct 11 has uniform cross section.

Advantageously, above-mentioned rectilinear duct 11 can realize in very simple mode as will be described hereinafter, for example by single block 17 is holed.

But, be apparent that, in structural change of the present invention not shown here, the surface area of the cross section of conduit assembly 10 can longshore current outgoing direction V continuously but not increase discretely.

Rectilinear duct 11 preferably is divided into according to three

group

12,13 and 14 that flows out direction V arranged in series, and total flow cross section of every group in described group is greater than total flow cross section of last group.

Especially, first group 12 and second groups 13 pipelines 11 that are provided with similar number, and the first end 12a of each pipeline of first group 12 is connected in the first end 13a of second group 13 corresponding pipeline by means of corresponding first connecting tube 15, in described first connecting tube 15 one in Fig. 3 fully as seen.

On the contrary, the 3rd group of pipeline 14 preferably but not necessarily comprise in the above-mentioned pipeline 11 two, the pipeline of these two pipelines 11 with respect to whole first group 12 and second groups 13 is arranged in opposition side.

Significantly, here in the unshowned different structural changes of the present invention, the group number of pipeline can be greater than three.

Equally significantly, in other structural change of the present invention, as long as total be provided with their flow cross section difference and at least two group pipelines that increase of longshore current outgoing direction V, then one or the multi units tube road can have identical total flow cross section.

As for the 3rd group of pipeline 14, each in them has the first end 14a, and the described first end 14a is connected in the second end 13b opposite with the corresponding first end 13a of second group of pipeline 13 by second connecting tube 16.

Significantly, unshowned different structural changes of the present invention can comprise some second connecting tubes 16 here, and each of described second connecting tube 16 can be connected in each pipeline of the 3rd group 14 one or more pipelines of second group 13.

Can notice, in the drawings, for brevity,

end

12a, 13a, 13b and the 14a of pipeline 11 only indicates once for every

group

12,13 and 14, be to be understood that this sign be repetition and for the end of other pipeline 11 of same group, also be identical.

Clearly show that more than conduit assembly 10 has total flow cross section of increase.

Consider fluid along the progressively evaporation of conduit assembly 10, the cross section of increase can make the speed of cooling fluid in the zones of different of conduit assembly 10 be optimized according to state and the specific volume of fluid itself.

Especially, the cross section of conduit assembly 10 is defined as to force fluid to flow with the even or variable velocity of fixing, thereby under any circumstance obtains the maximum heat efficiency that removes in every group of

pipeline

12,13 and 14.

Therefore, the conduit assembly 10 with cross section of increase provides the heat dissipation element of comparing known type higher heat exchange efficiency for coldplate 6, thereby realizes purpose of the present invention.As a result, advantageously, under the situation of identical hot-fluid to be dissipated, plate 6 of the present invention is compared known heat dissipation element needs lower cooling fluid flow rate.

Lower fluid flow rate advantageously makes the average flow cross section that reduces conduit assembly 10 in proportion and then the overall size of plate 6 become possibility.

And conduit assembly 10 is configured as and is similar to coil pipe, thus cooling fluid its motion of counter-rotating in

continuous duct bank

12,13 and 14 every group.

But different with the situation of the coil pipe of known type, the existence of parallel pipeline 11 more than in some parts of conduit assembly 10 has advantageously guaranteed the better distribution of fluid in plate 6, further improves its efficient thus.

Obviously, as long as the conduit assembly 10 that pipeline constitutes has total cross section of increase, then the pipeline of coldplate 6 can be according to the cooling needs of frequency converter 4 and be set to and arrange in every way with any number.

And second group of pipeline 13 should preferably include between first group of pipeline 12 and frequency converter 4, makes the contact surface 6a of second group of pipeline, 13 more close transducers 4, and be hotter at this place's plate 6, and first group of pipeline 12 is farther, colder at this place's plate 6.

Can be in Fig. 2 and Fig. 5 observed above-mentioned layout advantageously make and utilize the cooling capacity of fluid to become possibility best, the result further increases the efficient of plate 6.

In fact, compare when cooling fluid flows in second group of pipeline 13, when cooling fluid was in first group of pipeline 12, cooling fluid had bigger cooling capacity, and wherein cooling fluid warms in second group of pipeline 13.

Therefore, under the situation of arranging pipeline 11 as described above, the temperature of plate 6 and along the mean difference minimum between the temperature of the fluid of conduit assembly 10.

In other words, we have and two kinds of fluids between the similar situation of countercurrent flow situation, this countercurrent flow situation known to from thermodynamics, allows to obtain maximum heat exchange efficiency under the situation of identical fluid flow rate.

Preferably, each pipeline of conduit assembly 10 is the blind hole that obtains in the single block 17 that belongs to coldplate 6.

Especially, as shown in Figure 3, each pipeline of first group 12 is the opening 18a that first blind hole, 18, the first blind holes 18 have the first side 17a that is arranged in single block 17.

Similarly, the pipeline of second group 13 and the 3rd group 14 comprises second blind hole 19 and the 3rd blind hole 20 of similar number respectively, and described second blind hole 19 and the 3rd blind hole 20 have respective openings 19a and the 20a of the second side 17b opposite with the described first side 17a that is arranged in single block 17.

At last, connecting

tube

15 and 16 is respectively the 4th blind hole 21.

According to above-mentioned, as observing in cross section shown in Figure 4, preferably, second blind hole 19 is compared first blind hole 18 and is had bigger total cross section.

And, as can in the cross section of Fig. 5, observing better, be preferably perpendicular to first blind hole 18 and crossing with first blind hole 18 in the site of corresponding bottom 18b corresponding to the 4th blind hole 21 of first connecting tube 15.

As for second connecting tube 16 corresponding to the 4th blind hole 21, it is preferably perpendicular to second blind hole 19 and extends in the site of corresponding bottom 19b.

The opening 19a of second blind hole 19 and the 4th blind hole 21 and each among the 21a form conduit assembly 10 thus by corresponding connector 22 sealings.

Advantageously, because it has avoided at the outside pipe networks that use of plate 6, by means of the

blind hole

18,19 in the volume that is combined in

single block

17,20 and 21 and the conduit assembly 10 that obtains is conducive to the compactedness of coldplate 6.

And advantageously, it is structurally simpler that the plate 6 with the conduit assembly 10 that is combined in is wherein compared the plate that is provided with independent conduit assembly.

Also advantageously, because above-mentioned plate 6 has minimized number of components, the cost that its cost is compared similar coldplate is low.

As shown in Figure 2, coldplate 6 also comprises first head 23 and second head 24, and described first head 23 and second head 24 are associated with the first side 17a and the second side 17b of single block 17 respectively.

In first head 23, be provided with unshowned inlet manifold here, described inlet manifold functionally be connected in plate 6 entrance opening 7 and with the open communication of each first blind hole 18.

And first head 23 preferably also comprises entrance opening 7.

As for second head 24, described second head 24 is provided with especially visible outlet manifold (as according to the 3rd connecting tube of the present invention) 25 in Fig. 2 and Fig. 6, described outlet manifold 25 makes the 3rd blind hole 20 communicate with each other in the site of corresponding opening 20a, and preferably but not necessarily also be blind hole, the end 25a of this blind hole is by corresponding connector 22 sealings.

The exit opening 8 of plate 6 also is to form in second head 24 by means of the hole that is communicated with above-mentioned outlet manifold 25.

Fig. 7 shows the structural change of the coldplate that is theme of the present invention, and its integral body is by 30 expressions.

Because the blind hole 33 of the 3rd group of pipeline 31 is outside and include the pipeline 34 of exit opening 32 and functionally be connected to each other by means of being positioned at plate 30, so this modification is with aforesaid different.

As a result, plate 30 is not provided with second head, thereby means that its structure is fairly simple.

Clearly show that above above-mentioned plate 6 and 30 all has limited overall size, thereby making they are combined in the housing 2 of compressor 1 becomes possibility.

As a result, it is compacter that compressor 1 is compared the compressor with known type frequency converter, thereby realized another object of the present invention.

And if plate 6 and 30 is arranged in the compressor 1, it is particularly advantageous then by means of the identical working fluid of circulation in compressor 1 it being cooled off.

Preferably, plate 6 and 30

exit opening

8 and 32 are communicated with variable volume chambers 5a, make slave plate 6 and 30 fluids that flow out directly in the site of variable volume chambers 5a flows back to major loop in system.

Because the thermodynamic condition that the fluids that slave plate 6 and 30 flows out have a fluid that comprises among the chamber 5a with compressor 1 is thermodynamic condition very similarly, therefore described variable volume chambers 5a has represented the best point that is used for fluid is introduced in the loop.Therefore, advantageously, can improve the gross efficiency of system.

And the plate 6 and 30 that is integrated in the housing 2 of compressor 1 can be connected in chamber 5a by the access path 2a in the housing 2 that is placed in compressor 1, thereby has advantageously avoided meaning the exterior tube that increases overall size.

Viewpoint is seen and for plate 6, cooling fluid flows out from the major loop that compressor 1 is inserted in wherein under liquid condition and high pressure from operating.

Especially, as known and as described above, in cooling system, above-mentioned situation occurs in the downstream of condenser.

High pressure makes can be by choke valve 9 and the fluid that flows out by conduit assembly 10 transmission of plate 6 continuously, thereby advantageously makes and can avoid using suitable pumping equipment.

The choke valve 9 that functionally is connected in the entrance opening 7 of coldplate 6 has reduced pressure and the temperature of the fluid that flows out.

Fluid flows along the conduit assembly 10 of coldplate 6, in heat and the simultaneously evaporation of this place's absorption of fluids by frequency converter 4 generations.

Described choke valve 9 preferably but not necessarily be associated with first head 23 between entrance opening 7 and entrance menifold.

Obviously, above-mentioned situation can also be applied to modification shown in Figure 7 30 similarly.

Above show is that plate and the compressor of theme of the present invention realized all setting purposes.

Especially, the present invention has realized producing the purpose of the higher coldplate of the heat dissipation element efficient of comparing known type, thus make can confinement plate itself overall size.

And the present invention has realized producing the purpose of the compacter compressor with frequency converter of the compressor of comparing similar known type.

In force, although not shown or description here is that plate and the compressor of theme of the present invention can further be changed, yet as long as described change falls in the scope of claims, this patent will cover these changes.

When the technical characterictic of mentioning in arbitrary claim is followed the drawings attached mark, include these Reference numerals only for increasing the intelligibility of claim, therefore, these Reference numerals do not have any restriction to the understanding of each element of being identified by way of example by these Reference numerals.

Claims

1. coldplate (6 that is used for frequency converter (4); 30), described coldplate (6; 30) comprise surface (6a) and conduit assembly (10), described surface (6a) is suitable for connecting with described frequency converter (4), and described conduit assembly (10) is arranged in entrance opening (7) and exit opening (8; 32) between, described entrance opening (7) and described exit opening (8; 32) limit cooling fluid along the outflow direction (V) of described conduit assembly (10), wherein:

-described conduit assembly (10) comprises a plurality of rectilinear duct (11) that are arranged side by side, and each described rectilinear duct (11) has uniform cross section;

-described rectilinear duct (11) comprises first group of pipeline (12) and second group of pipeline (13), and described second group of pipeline (13) is arranged in the downstream of described first group of pipeline (12) according to described outflow direction (V);

Total flow cross section of-described second group of pipeline (13) is greater than described first group of pipeline

(12) total flow cross section;

First end (12a) of each pipeline in-described first group of pipeline (12) is connected in first end (13a) of the corresponding pipeline in described second group of pipeline (13) by corresponding first connecting tube (15);

It is characterized in that described second group of pipeline (13) is included between described first group of pipeline (12) and the described frequency converter (4).

2. coldplate (6 as claimed in claim 1; 30), it is characterized in that described rectilinear duct (11) comprises the 3rd group of pipeline (14; 31), described the 3rd group of pipeline (14; 31) total flow cross section equals total flow cross section of described second group of pipeline (13) at least.

3. coldplate (6 as claimed in claim 2; 30), it is characterized in that second end (13b) of each pipeline in described second group of pipeline (13) is connected in first end (14a) of the pipeline in described the 3rd group of pipeline (14) by at least one second connecting tube (16).

4. each described coldplate (6 in the claim as described above; 30), it is characterized in that described coldplate (6; 30) comprise single block (17), described single block (17) is provided with a plurality of holes (18,19,21,20 that limit described conduit assembly (10); 33).

As with claim 3 in conjunction with the time the described coldplate (6 of claim 4; 30), it is characterized in that each pipeline in described first group of pipeline (12) is first blind hole (18), each pipeline in described second group of pipeline (13) is second blind hole (19), described the 3rd group of pipeline (14; 31) each pipeline in is the 3rd blind hole (20; 33), each in described first connecting tube (15) and described second connecting tube (16) is the 4th blind hole (21).

6. coldplate (6 as claimed in claim 5; 30), it is characterized in that, the opening (18a) of described first blind hole (18) is arranged on first side (17a) of described single block (17), and the opening (19a) of described second blind hole (19) is arranged on second side (17b) relative with described first side (17a) of described single block (17).

7. coldplate (6 as claimed in claim 6; 30), it is characterized in that (19a 21a) is sealed by connector (22) opening of described second blind hole (19) and described the 4th blind hole (21).

8. coldplate (6 as claimed in claim 5; 30), it is characterized in that described coldplate (6; 30) comprise first head (23), described first head (23) is associated with first side (17a) of described single block (17) and is provided with the entrance menifold, and described entrance menifold functionally is connected in described entrance opening (7) and is communicated with the opening (18a) of described first blind hole (18).

9. coldplate as claimed in claim 5 (6), it is characterized in that, described coldplate (6) comprises second head (24), described second head (24) is associated with second side (17b) of described single block (17) and is provided with the 3rd connecting tube (25), and described the 3rd connecting tube (25) is suitable for connecting the opening (20a) of described the 3rd blind hole (20).

10. a compressor (1), described compressor (1) comprises housing (2), described housing (2) holds electro-motor (3), described electro-motor (3) is by frequency converter (4) feeding and functionally be connected in compression set (5) for compression working fluid, it is characterized in that described compressor (1) comprises the coldplate (6 according to each realization in the aforementioned claim; 30), described coldplate (6; 30) contact surface (6a) is arranged in contact with described frequency converter (4).

11. compressor as claimed in claim 10 (1) is characterized in that, described coldplate (6; 30) and described frequency converter (4) be arranged in the described housing (2).

12. compressor as claimed in claim 11 (1) is characterized in that, described compression set (5) limits at least one variable volume chambers (5a), and described variable volume chambers (5a) is provided with for the ingress path of described working fluid and a transport path.

13. compressor as claimed in claim 12 (1) is characterized in that, described housing (2) comprises the described exit opening (8 that is positioned at described variable volume chambers (5a) and described coldplate; 32) access path between (2a).

14. as each described compressor (1) in the claim 10 to 13, it is characterized in that described compressor (1) comprises choke valve (9), described choke valve (9) functionally is connected in described coldplate (6; 30) described entrance opening (7).