DE102016108555A1 - Scroll machine with adjustable volume ratio - Google Patents

Abstract

The invention relates to an adjustable volume ratio scroll machine comprising a first base plate (2a) and a second base plate (2b) each having a scroll spiral (3,4) disposed thereon, the engaged scroll spirals (3, 4) of both base plates (2a , 2b) are orbitingly movable relative to one another, wherein the scrolling machine (1) has a volume V1 of a fluid in an inlet region (5) at the moment of closing a suction region (7) and a volume V2 of a fluid in a high-pressure region (8) at the moment of opening a compression chamber (6) formed by the scroll spirals (3, 4), wherein the ratio of the volumes V1 and V2 defines a volume ratio, wherein the scroll spirals (3, 4) can be coupled via a transition zone (14) to a connected system and the Transition zone (14) the suction area (7) when operating as a compressor and the outlet area (7) when operating as an expander, characterized gekennzeic hnet that at least one variable means (9, 11) for influencing an opening time and / or opening cross section of the transition zone (14) is provided and arranged and designed in such a way that a fluid volume flow over the transition zone (14) continuously controllable, so that Fluid volume in one with the transition zone (14) connected to the low pressure region (5) of the scroll machine (1) adjustable and the volume ratio of the scroll machine (1) are variable.

Description

The invention relates to a scroll machine with adjustable volume ratio and variable displacement. A scroll machine, also referred to as scroll compressor or scroll auger, is a machine that compresses or expands gases. It consists of two nested scroll spirals whose opposite movement compresses or expands the gas. A scroll machine works according to the displacement principle. Of the two nested scroll spirals, one is typically stationary and the other is eccentrically moved on a circular path. The scroll spirals keep a minimum distance from each other or slide or roll off each other, but at least two constantly decreasing chambers in each case during compressor operation in both cases. As a result, the gas to be delivered is sucked in the outside, compressed inside the compressor and ejected via a connection in the center of the scroll spirals during compressor operation. In an expansion process, the agent is sucked in the middle of the spiral and the process is reversed accordingly.

In order to achieve very high pressure conditions - for example for chillers or heat pumps - several pairs of spirals can be arranged in succession on the same shaft, so that the individual compression ratios multiply.

Scroll machines have due to their work space-limiting scroll spirals and the respectively associated base plate and the orbiting movement of the scroll spirals to each other on an edge-controlled operation. That the enclosed volume at the moment of closure of a suction chamber at the suction area (volume V1) and the enclosed volume at the moment of opening a chamber towards the exit (volume V2) are geometrically determined by the geometry of the scroll spirals and by the movement of the two scroll spirals relative to one another. This applies equally to compression machines and expansion machines.

The volume ratio of a scrolling machine, which results from the ratio of the volumes V1 to V2, is thus invariable without further measures and is referred to as the built-in volume ratio (BIVR). The inlet and outlet volumes are, depending on the operating mode compression or expansion, exactly opposite to understand. A high isentropic grade is achieved especially when the volume ratio of the scroll machine matches the volume ratio of the connected system. However, this fixed volume ratio prevents a corresponding grade, which is considered as a measure of the energetic evaluation of the compression or expansion process. If the volume ratio deviates from that of the connected system, the isentropic quality factor is reduced due to so-called under- or over-compression.

In view of these disadvantages, the prior art has already tried to remedy the situation. Constructive means and measures were offered which allow a change of the built-in volume ratio.

The publication US 4 497 615 A For this purpose, additional bores are provided in addition to the usually centrally located "outlet bore". This causes an opening when the high pressure is exceeded, which helps to avoid over compression and efficiency losses. The disadvantage, however, are overflow losses through the bores and the occurring inertial forces and the dynamics of the components, since the valves are opened and closed at each revolution.

Furthermore, the document describes EP 1199474 A2 a stepwise adjustable volume ratio with valve-controlled delivery. The disadvantage, however, is that continuous adaptation is not possible.

The publication US Pat. No. 6,413,058 B1 offers a solution in which the crescent-shaped scroll chambers are kept open longer. For this purpose, bores are provided which connect the scroll chambers with the Saugdruckvorkammer. Again, a continuous adjustment is not possible, also this solution leads to a reduced efficiency.

Similarly, the scroll machines solve the pamphlets DE 103 51 519 A1 and DE 11 2011 101 873 T5 the problem, in which case the holes are variably closed. A flap control (diverting flaps) is provided at the outlet of the scroll set and thus represents another type of solution.

The publication EP 1 701 039 B1 provides a scrolling machine with a deformable element having an adjusting element for adjusting a distance between two scroll spirals. As a result, although the capacity of the working chamber can be varied, but not the adjustment of the volume ratio between the inlet and outlet volume. Additionally occur through the column flow losses during the backflow to the low pressure area.

The publication US 4 129 405 A describes a scroll machine for pumping liquids, are provided at the inner and / or outer transfer passages. Sliders are not provided, just an "overflow". However, overrunning the moving scroll can lead to the unwanted opening of a flow path into other compression or expansion pockets.

Other well-known solutions provide that the fixed scroll spiral temporarily lifts off axially from the orbiting scroll spiral. This process is called Digital Scroll Technology offered by Emerson Climate Technologies. This results in an increase in the leakage with the result of a variably adjustable flow rate. Again, a reduction in efficiency due to higher losses is to be mentioned as a disadvantage.

Likewise, the intermediate injection of liquid or gaseous refrigerant is known in the compression process. This technology is laborious because additional equipment is required for injection.

Overall, the solutions according to the prior art he shared that a continuous adjustment is not guaranteed or only at the cost of considerable Überströmverlusten. Furthermore, all presented methods with significant losses due to transient overflow through narrow cross sections are not lossless, i. the principles are partly based on the targeted use of a loss mechanism. Furthermore, the known solutions are characterized by a complex and complicated construction.

The object of the present invention is therefore to provide a scrolling machine with a continuously adjustable delivery volume, which works as low as possible and has a simple structure.

The object is achieved by a scrolling machine with adjustable volume ratio, comprising a scrollset having a first and a second base plate, each having a scroll spiral arranged thereon, wherein the engaged scroll spirals of both base plates are orbitally movable towards each other.

The scroll machine includes a volume V1 of a fluid in an inlet area at the moment of closing a suction chamber and a volume V2 of a fluid in a high pressure area at the moment of opening a compression chamber formed between the scroll spirals. The ratio of the volumes V1 and V2 defines a volume ratio. The scroll spiral can be coupled via a transition zone with a first connected system, from which the fluid to be compressed is transferred or into which the expanded fluid is to be delivered. The scroll machine has a suction area when operating as a compressor and an outlet area when operating as an expander. Between this area and the low-pressure area is a transition zone, since there the transition of the fluid between "outside", ie the connected system, and "within", for example, the low pressure region of the scroll machine, takes place.

To achieve the object according to the invention, a variable means for influencing an opening time and / or an opening cross-section of the transition zone is provided and arranged and configured in such a way that a fluid volume flow over the transition zone is infinitely controllable. Thus, at the same time the volume of fluid in a connected to the transition zone low pressure region of the scroll machine is adjustable with the result that the volume ratio of the scroll machine is changeable. The ratio is already changed when one of the two volumes V1 and V2 is changed.

Preferably, as a variable constructive means, a slide is provided, which controllably connects the suction region or the outlet region with a low pressure region of the scrolling machine in such a way that during operation the time for opening or the opening cross-section (or both) of the suction chamber for the compressor operation or the outlet chamber are continuously controllable for expander operation. The slider is preferably arranged on the first base plate of the stationary, first scroll spiral.

Particularly preferably, the slider is movable in the circumferential direction, in the radial and / or axial direction. It may also be moved or following a predetermined path containing both axial and radial motion components. The thickness of the slider is to be selected in particular in the circumferential direction so that a run over by the moving scroll does not take place for unintentional opening of a flow path into other compression or expansion pockets. This feature overcomes in particular the disadvantages of the document US 4 129 405 A ,

It has proved to be advantageous if the slide is designed as a kidney-shaped, in particular, feasible in the base plate rotary valve.

As an alternative to the rotary valve, the slide is designed as an arrangement of sliding blocks. A combination of both types of sliders is also provided.

It is further encompassed by the invention, when the arrangement of predominantly radially movable pusher blocks is designed as part of the base plate and the pusher stones can be pulled individually. Dragging or pressing the Sliding blocks can either form fit, such as by a suitable device, or force-locking, such as by an externally applied magnetic force done. The impressing of a magnetic force can preferably be generated by a kidney-shaped, predominantly radially moving magnet, which generates a sufficient attraction or repulsion force when approaching the sliding block.

An advantageous development comprises a mechanical adjusting device, with the aid of which the position of the respective slider is adjustable from the outside. This can be done either manually or controlled or automatically

It has also proven to be advantageous if a pressure adjustment device is provided, with the aid of which the position of the slide can be adjusted internally via present pressure conditions, in particular low pressure, high pressure and / or differential pressure.

The object is further achieved by a method for setting a maximum isentropic grade for an operating point of a scroll machine by adjusting a volume ratio of volumes V1 and V2, wherein a volume V1 in an inlet region at the moment of closing a suction and a volume V2 in a high pressure region in Moment of opening a compression chamber are included, wherein the ratio of the volumes V1 and V2 defines a volume ratio, the scroll spiral is coupled via a transition zone and the suction in an operation as a compressor and the outlet region when operating as an expander with a first connected system and the transition zone forms the intake area in an operation as a compressor and the outlet area in an operation as an expander, wherein at least one variable means influence an opening time and / or an opening cross section of the transition zone and a Fluid volume flow continuously controlled over the transition zone, so that the fluid volume is adjusted in a connected to the transition zone low pressure region of the scroll machine and the volume ratio of the scroll machine are changed.

The invention provides a structurally simple to implement, low-loss solution and allows a continuous adjustment of the stroke volume even during operation. As a result, the system thus equipped can also be automated.

Further details, features and advantages of the invention will become apparent from the following description of exemplary embodiments with reference to the accompanying drawings. Show it:

1 a schematic representation of the operation of a conventional scroll set;

2 a schematic perspective view of a conventional scroll set, consisting of two scroll spirals;

3 a schematic plan view of the scrollset;

4 a schematic plan view of a low pressure region of an embodiment of a scroll set according to the invention with rotary valve;

5 : Top view of the low-pressure region of an embodiment of the scroll set according to the invention with pusher blocks; and

6 : A flow chart of a scroll set according to the invention.

1 shows a schematic representation of the operation of a conventional scrollset 1 in the prior art continuous compression. The scrollset 1 with the counter-orbiting scroll spirals 3 . 4 , each arranged on a base plate 2a . 2 B , opens on the first of the four stages shown (from left) an inlet area (dotted marked area). Upon further movement, this area is trapped and forms a compression chamber 6 , Their volume decreases with progressive orbital movement of the scroll spirals 3 . 4 (represented by increased point density). The highest compression is in the center of the scroll spirals 3 . 4 reached where the compression chamber 6 has reached the lowest volume and the compressed fluid into an outlet area 7 is delivered.

2 shows a schematic perspective view of a conventional scroll set 1 , consisting of two scroll spirals 3 . 4 , for reasons of clarity, only the first base plate 2a the first scroll spiral 3 is shown. The second scroll spiral 4 reaches into the first scroll spiral 3 one.

3 shows a schematic plan view of the known scrollset 1 as it is too 2 and in its function too 1 already described.

4 shows a schematic plan view of a low pressure region of an embodiment of a scroll set according to the invention 1 with rotary valve 9 for connecting a suction region (in the case of a compressor) or of the outlet region (in the case of an expander) to the low-pressure region of the scrolling machine 1 , so on the outside of the scroll spirals 2 . 4 ,

The slide, here as a rotary valve 9 executed, separates an open area 12 from a closed area 13 , where the direction of movement 10 of the slider 9 indicated by an arrow.

5 shows a plan view of the low pressure region of an embodiment of the scroll set according to the invention 1 with radially movable pusher blocks 11 (represented by individual arrows) for connecting the suction region (in a compressor) and the outlet region (in the case of an expander) to the low-pressure region of the scrolling machine. The area where the pusher stones 11 moved out of their rest position forms the closed area 13 while in the open area 12 the pusher stones 11 remain in their rest position.

6 shows for a better understanding of the invention, a schematic arrangement of the solution according to the invention in a flow chart, wherein the function of the scroll machine is shown as a compressor. The fluid flows from a first connected system into the scroll machine 1 over the intake area 7 one to the low pressure area 5 to fill, where the compression starts from. According to the invention, however, the inflowing fluid becomes in the transition region 14 through the slider 9 . 11 , shown here as a valve, controlled. The slider 9 . 11 is from the outside by an adjustment 15 operable. This can be z. B. mechanically or magnetically, the adjustment can also be made via an automatic process.

So only a part of the fluid enters the low-pressure area (volume V1), which would arrive there without any influence. So sets a different volume ratio of volume V1 to volume V2, as this without slider 9 . 11 the case would be. From the low pressure area 5 the fluid is between the scroll spirals 3 . 4 containing the compression chamber 6 form, more and more compressed until the high pressure area 8th is achieved with the minimum volume V2 and the highest pressure. From the high pressure area 8th The fluid compressed to the volume V2 flows off into the second connected system.

LIST OF REFERENCE NUMBERS

1

Scroll machine

2a

first base plate

2 B

second base plate

3

first scroll spiral

4

second scroll spiral

5

Low pressure area, inlet area

6

compression chamber

7

Outlet area or intake area

8th

High pressure area

9

Slide, rotary valve, variable means

10

movement direction

11

Slider, variable means

12

open area

13

closed area

14

Transition zone

15

adjustment

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 4497615 A [0006]
• EP 1199474 A2 [0007]
• US 6413058 B1 [0008]
• DE 10351519 A1 [0009]
• DE 112011101873 T5 [0009]
• EP 1701039 B1 [0010]
• US 4,129,405 A [0011, 0020]

Claims (10)

Adjustable volume ratio scroll machine comprising a first base plate ( 2a ) and a second base plate ( 2 B ) each having a scroll spiral arranged thereon ( 3 . 4 ), the engaged scroll spirals ( 3 . 4 ) of both base plates ( 2a . 2 B ) are orbiting movable to each other, wherein the scrolling machine ( 1 ) a volume V1 of a fluid in an inlet region ( 5 ) at the moment of closing a suction area ( 7 ) and a volume V2 of a fluid in a high pressure region ( 8th ) at the moment of opening one by the scroll spirals ( 3 . 4 ) formed compression chamber ( 6 ), wherein the ratio of the volumes V1 and V2 defines a volume ratio, wherein the scroll spirals ( 3 . 4 ) via a transition zone ( 14 ) can be coupled with a connected system and the transition zone ( 14 ) the intake area ( 7 ) when operating as a compressor and the outlet area ( 7 ) when operating as an expander, characterized in that at least one variable means ( 9 . 11 ) for influencing an opening time and / or an opening cross section of the transition zone ( 14 ) and arranged and designed in such a way that a fluid volume flow over the transition zone ( 14 ) continuously controllable so that the volume of fluid in one with the transition zone ( 14 ) associated low pressure area ( 5 ) of the scroll machine ( 1 ) and the volume ratio of the scroll machine ( 1 ) are changeable. Scrolling machine according to claim 1, wherein as a variable means a slider ( 9 ) on the first base plate ( 2a ) of the stationary, first scroll spiral ( 3 ) is provided. Scroll machine according to claim 2, wherein the slider ( 9 ) is movable in the circumferential direction, in the radial and / or axial direction. Scrolling machine according to claim 2 or 3, wherein the slider ( 9 ) than in the base plate ( 2a . 2 B ) feasible rotary valve is formed. Scrolling machine according to claim 2 or 3, wherein the slider ( 9 ) as an array of pusher blocks ( 11 ) is executed. Scroll machine according to claim 5, wherein radially movable sliding blocks ( 11 ) as part of the base plate ( 2a . 2 B ) are executed and can be pulled or expressed individually. Scrolling machine according to claim 5 or 6, wherein expressions or drawing of the sliding blocks ( 11 ) be made form-fitting or non-positively by an externally applied magnetic force. Scrolling machine according to one of claims 2 to 7, wherein a mechanical adjusting device ( 15 ) is provided, with the help of which the position of the slide ( 9 . 11 ) is conceivable from the outside. Scrolling machine according to one of claims 2 to 8, wherein a pressure manipulatable adjusting device ( 15 ) is provided, with the help of which the position of the slide ( 9 . 11 ) is internally adjustable via existing pressure conditions low pressure, high pressure and / or differential pressure. Method for setting a maximum isentropic grade for an operating point of a scrolling machine ( 1 by adjusting a volume ratio of volumes V1 and V2, wherein a volume V1 in an inlet area ( 5 ) at the moment of closing a suction area ( 7 ) and a volume V2 in a high-pressure region ( 8th ) at the moment of opening a compression chamber ( 6 ), wherein the ratio of the volumes V1 and V2 defines a volume ratio, wherein the scroll spiral ( 3 . 4 ) via a transition zone ( 14 ) and the intake area ( 7 ) when operating as a compressor and the outlet area ( 7 ) can be coupled in an operation as an expander with a first connected system, characterized in that at least one variable means ( 9 . 11 ) an opening time and / or an opening cross section of the transition zone ( 14 ) and a fluid volume flow over the transition zone ( 14 ) is continuously controlled so that the volume of fluid in one with the transition zone ( 14 ) connected low pressure area ( 5 ) of the scroll machine ( 1 ) and the volume ratio of the scrolling machine ( 1 ) to be changed.

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