DE102018124301A1 - Scroll compressor - Google Patents

Abstract

The invention relates to a scroll compressor, comprising a housing (9) with a suction inlet (10) and a system outlet (11), a first scroll element (13) fixedly arranged in the housing (9) with one on a first plate (14). formed spiral (15), one in the housing (9) rotatably arranged second scroll member (1) formed on a second plate (12) second spiral (2), which with the first spiral (15) rotated at an angle and radially staggered arranged such that the second spiral (2) during a rotation of the second scroll member (1) on the first spiral (15) to form a suction chamber (SC), a middle chamber (MC) and an outlet chamber (DC) is unrolled wherein in the first plate (14) has two eccentrically arranged pre-outlets (3) which are each shut off with a valve (16), and a centrally arranged main outlet (4) for a via the suction inlet (10) supplied refrigerant are formed, wherein the Scrollverdicherter characterized in that the main outlet (4) opens into a dead volume having outlet cavity (17) which is formed between the main outlet (4) and the system outlet (11) and a Outlet valve (18) in the direction of the system outlet (11), wherein at the mouth of the main outlet (4) in the outlet cavity (17) no valve (16) is provided for shutting off the main outlet (4).

Description

The invention relates to a scroll compressor which operates efficiently in air conditioning operation and in heat pump operation.

Scroll compressors for refrigeration circuits of air conditioning systems are usually designed so that they work primarily in the air conditioning operation, that is, in cold operation, efficient. The goal is low power consumption at maximum flow rate. This leads to low outlet temperatures at a certain pressure ratio and speed. In a heat pump cycle, however, it is necessary to achieve high outlet temperatures to heat the cabin interior. With an efficient ScrollKompressor therefore high pressure conditions must be achieved in order to achieve a high outlet temperature. At higher pressures, however, the volumetric efficiency drops and the compressors become inefficient. The bearing loads also increase.

Conventional scroll compressors with a wrap angle in the range of 440 ° to 900 ° require two pre-outlets and a main outlet for efficient operation. Each outlet is closed with a valve after the pressure in a compression chamber falls below the high pressure. This avoids that hot gas flows back into the compression chamber and the compressor becomes inefficient. For this reason, A / C compressors according to the prior art have triple exhaust valves, the so-called 3-finger valve. For a scroll compressor operating in a heat pump cycle where high exhaust gas temperatures are required, it would be advantageous for hot gas to flow back into the compression chamber.

The object of the invention is now to propose a refrigerant scroll compressor, which operates efficiently both in the air conditioning mode (air condition) and in the heat pump operation.

The object is achieved by a scroll compressor with the features according to claim 1. Further developments are specified in the dependent claims.

The solution is to design the scroll geometry so that, under all A / C conditions, the high pressure is reached before the refrigerant can escape through the main outlet port. Therefore, no valve is required at the main outlet. It has been found that omitting the valve at the main outlet, creating an additional dead volume, has no negative impact on performance. In the state of the heat pump, the pre-discharge valves remain closed and the entire refrigerant leaves the main outlet. Backflow from the high pressure side results in poor compression and high outlet temperatures at low pressure ratios.

The scroll compressor according to the invention has a housing with a suction inlet and a system outlet. In the housing, a first scroll element is arranged fixed with a spiral formed on a first plate. Furthermore, the housing comprises a rotatably arranged second scroll element with a formed on a second plate second spiral, which is rotated with the first spiral at an angle and radially offset arranged such that the second spiral upon rotation of the second scroll member on the first spiral forming a suction chamber, a central chamber and an outlet chamber is unrolled, wherein in the first plate two eccentrically arranged pre-outlets, which are each shut off with a valve, and a centrally disposed main outlet for a supplied via the suction inlet refrigerant are formed. The main outlet terminates in a dead volume outlet cavity formed between the main outlet and the system outlet and having an outlet valve toward the system outlet. In this case, no valve for shutting off the main outlet is provided at the mouth of the main outlet in the outlet cavity. The outlet valve and the outlet cavity may be secured in the housing with a bracket.

The advantage of the invention is that the scroll compressor, which may also be referred to as a scroll compressor or simply a compressor, may operate at lower pressures and lower speeds in heat pump mode. This leads to better NVH, lower energy consumption and lower bearing load. Advantageously, thereby a longer life of bearings can be achieved or the bearing size can be reduced. A significant advantage is further that the scroll compressor according to the invention has an improved shutdown NVH behavior.

According to one embodiment variant of the scroll compressor according to the invention, provision may be made for the entire cavity of the housing part designated as the rear head to form the outlet cavity on the outlet side of the scroll compressor, the volume of the outlet cavity corresponding to the dead volume. It can be provided that the main outlet and the two pre-outlets open into the outlet cavity. Furthermore, the outlet cavity may be formed with a dome, which is arranged on the outlet side of the first plate and covering the main outlet and the two outlets.

According to a further embodiment variant of the scroll compressor according to the invention, in which only the main outlet opens into the outlet cavity, the outlet cavity is formed with a dome, which is arranged on the outlet side of the first plate and thereby covers the main outlet, wherein the two pre-outlets into a gap formed between the outlet cavity and the system outlet. Conveniently, it may be provided that there is a gap between the outlet cavity and the system outlet. In this case, the intermediate space may be formed such that the two pre-outlets and the outlet of the outlet cavity open into the intermediate space.

Advantageously, the scroll compressor according to the invention can have a Gesamtumschlingungswinkel of 660 °. This makes it possible that between the scrolls of the scroll elements each have a suction chamber, a central chamber and an outlet chamber are formed. In this case, the required high pressure is always achieved in the middle chamber under all test points, without the main outlet is shut off with a valve. Only open and close the pre-outlets.

The invention further includes application of the scroll compressor described above in air conditioning mode or in heat pump mode, wherein the valves of the pre-outlets are opened and closed in the air conditioning mode to produce refrigeration, and wherein the valves of the pre-outlets remain closed in heat pump operation to generate heat ,

• 1: eine schematische Darstellung eines Scrollelements eines Scrollverdichters,
• 2: ein 3-Finger-Ventil nach dem Stand der Technik,
• 3: eine schematische Schnittdarstellung einer ersten Ausführungsvariante des erfindungsgemäßen Scrollverdichters,
• 4: eine schematische Schnittdarstellung einer zweiten Ausführungsvariante des erfindungsgemäßen Scrollverdichters,
• 5: eine schematische Schnittdarstellung einer dritten Ausführungsvariante des erfindungsgemäßen Scrollverdichters,
• 6: eine erste schematische Darstellung zur Detailbeschreibung des Klimaanlagenmodus,
• 7: eine zweite schematische Darstellung zur Detailbeschreibung des Klimaanlagenmodus,
• 8: ein Diagramm der isotropen Verdichtung des Scrollverdichters zur Detailbeschreibung des Klimaanlagenmodus und
• 9: ein Diagramm der isotropen Verdichtung des Scrollverdichters zur Detailbeschreibung des Wärmepumpenmodus.

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

• 1 FIG. 2: a schematic representation of a scroll element of a scroll compressor, FIG.
• 2 : a 3-finger valve according to the prior art,
• 3 FIG. 2 is a schematic sectional view of a first embodiment variant of the scroll compressor according to the invention, FIG.
• 4 FIG. 2 is a schematic sectional view of a second embodiment variant of the scroll compressor according to the invention, FIG.
• 5 FIG. 2 is a schematic sectional view of a third embodiment variant of the scroll compressor according to the invention, FIG.
• 6 : a first schematic representation for a detailed description of the air conditioning mode,
• 7 : a second schematic representation for a detailed description of the air conditioning mode,
• 8th : a diagram of the scroll compressor isotropic compression to the detailed description of the air conditioning mode and
• 9 : A diagram of the isotropic compression of the scroll compressor for a detailed description of the heat pump mode.

Recurring features are identified in the figures with the same reference numerals.

The 1 shows a scroll element 13 in the presentation A with spiral 15 , two sub-outlets 3 and a main outlet 4 , The representation B shows the outlet-side design of the scroll element 13 with the two sub-outlets 3 and the main outlet 4 ,

The 2 shows a so-called 3-finger valve 5 as is the case in the prior art for shutting off the two pre-outlets 3 with the fingers or leaves 6 and to shut off the main outlet 4 with the main leaf or center leaf 7 is in use. The 3 -Finger valve allows simultaneous opening and closing of the pre-outlets 3 and the main outlet 4 ,

After the design of the scroll compressor according to the invention is at the main outlet 4 No valve provided so that the main outlet 4 always open, with the main outlet 4 opens into an outlet cavity.

3 shows a schematic sectional view of a first embodiment of the scroll compressor according to the invention. The scroll compressor according to the invention has a housing 9 with a suction inlet 10 and a system outlet 11 on. In the case 9 is a first scroll element 13 with one at a first plate 14 trained first spiral 15 fixed arranged. Furthermore, the housing comprises 9 a rotatably arranged second scroll element 1 with one on a second plate 12 trained second spiral 2 , which with the first spiral 15 rotated at an angle and radially staggered arranged such that the second spiral 2 upon rotation of the second scroll element 1 on the first spiral 15 under formation of a suction chamber SC , a middle chamber MC and an outlet chamber DC (please refer 6 and 7 ), wherein in the first plate 14 two eccentrically arranged pre-outlets 3 , each with a valve 16 can be shut off, and a centrally arranged main outlet 4 for one over the suction inlet 10 supplied refrigerant are formed. The main outlet 4 opens into a dead volume having outlet cavity 17 which is between the main outlet 4 and the system outlet 11 is formed and an exhaust valve 18 towards the system outlet 11 having. It is at the mouth of the main outlet 4 in the outlet cavity 17 no valve to shut off the main outlet 4 intended. The outlet valve 18 and the outlet cavity 17 are in the case 9 with a holder 19 attached. In this embodiment, the pre-outlets open 3 and the main outlet 4 in the outlet cavity 17 ,

The 4 shows a schematic sectional view of a second embodiment of the scroll compressor according to the invention as in 3 , with the difference that the outlet cavity 17 with a dome 8th is formed, only the main outlet 4 covered so that the sub-outlets 3 in a gap 20 flow into the dome 8th and the system outlet 11 is formed.

The 5 shows a schematic sectional view of a third embodiment of the scroll compressor according to the invention as in 4 , with the difference that the dome 8th is designed such that it the pre-outlets 3 and the main outlet 4 covered so that the sub-outlets 3 and the main outlet 4 in the outlet cavity 17 lead.

The 6 and 7 show schematic representations for a detailed description of the air conditioning mode. Shown are each different rotation angle of the first spiral 15 and the second spiral 2 , being between the spirals 15 and 2 one suction chamber each SC , a middle chamber MC and an outlet chamber DC are formed. The 6A shows a rotation angle of 0 ° or 360 °, wherein the suction chamber SC a pressure of 35 bar, the middle chamber MC a pressure of 130 bar and the outlet chamber DC have a pressure of 130 bar. In contrast to 6A is the rotation angle in 6B 90 °, the middle chamber MC has a pressure of 45 bar.

7A shows a rotation angle of 180 °, the middle chamber MC has a pressure of 57 bar. At a rotation angle of 270 °, as in 7B is shown, the middle chamber MC a pressure of 79 bar.

8th shows a diagram of the isentropic compression of the scroll compressor for detailed description of the air conditioning mode in area 21 and in the area 22 in which the valves 16 the pre-outlets 3 in the area 21 be opened and closed. There is no flow of high pressure in the combined internal compression chamber emerging from the outlet chamber DC and the outlet cavity 17 is formed, although no main exhaust valve at the main outlet 4 is available. The outlet chamber DC and outlet cavity 17 are at the same level. The compressor has low outlet temperatures. The total wrap angle is 660 °, so that the three compression chambers (suction chamber SC , Middle chamber MC and outlet chamber DC ) can always be formed. Due to the properties of the specific refrigerant CO ₂ , the necessary high pressure is achieved at all climatic check points within the middle chamber MC achieved (360 ° rotation angle). Therefore, no main exhaust valve is required. Only the sub-outlets 3 close and open.

9 shows a diagram of the isentropic compression of the scroll compressor for a detailed description of the heat pump mode in the area 21 and in the area 22 , In heat pump mode, the valves remain 16 the pre-outlets 3 closed. A high pressure flow is possible because the main outlet 4 always open. The pressure in the compression chamber is at a lower pressure level than the pressure in the outlet cavity 17 , The scroll compressor has high outlet temperatures, which are required for efficient operation of the heat pump.

LIST OF REFERENCE NUMBERS

1

Second scroll element

2

Second spiral

3

Before outlets

4

Main outlet

5

3-finger valve

6

Finger / leaves

7

Main sheet / middle sheet

8th

dome

9

casing

10

suction inlet

11

System outlet

12

Second plate

13

First scroll element

14

First plate

15

First spiral

16

Valve

17

exhaust cavity

18

outlet valve

19

holder

20

gap

21

Range of sub-outlets

22

Area of the main outlet

SC

Suction / suction chamber

MC

middle chamber

DC

outlet

LP

Suction pressure / low pressure

HP

Outlet pressure / high-pressure

Claims (6)

Scroll compressor, comprising a housing (9) with a suction inlet (10) and a system outlet (11), a first scroll element (13) fixed in the housing (9) with a first spiral formed on a first plate (14) ( 15), a second scroll member (1) rotatably disposed in the housing (9) and having a second scroll (2) formed on a second plate (12) rotated at an angle with the first scroll (15) and radially staggered is plugged together that the second spiral (2) during a rotation of the second scroll member (1) on the first spiral (15) to form a suction chamber (SC), a middle chamber (MC) and an outlet chamber (DC) is unrolled, wherein the first plate (14) has two eccentrically arranged pre-outlets (3), each of which can be shut off with a valve (16), and a centrally arranged main outlet (4) for a refrigerant supplied via the suction inlet (10), dadu characterized in that the main outlet (4) opens into a dead volume outlet cavity (17) formed between the main outlet (4) and the system outlet (11) and an outlet valve (18) in the direction of System outlet (11), wherein at the mouth of the main outlet (4) in the outlet cavity (17) no valve (16) is provided for shutting off the main outlet (4). Scroll compressor after Claim 1 , characterized in that the main outlet (4) and the two pre-outlets (3) open into the outlet cavity (17). Scroll compressor after Claim 1 or 2 characterized in that the outlet cavity (17) is formed with a dome (8) disposed on the outlet side of the first plate (14) and thereby the main outlet (4) or the main outlet (4) and the two Pre-outlets (3) covered. Scroll compressor after one of the Claims 1 to 3 characterized in that a gap is formed between the outlet cavity (17) and the system outlet (11). Scroll compressor after one of the Claims 1 to 4 characterized in that the scroll compressor has a Gesamtumschlingungswinkel of 660 °. Application of a scroll compressor after the Claims 1 to 5 in the air conditioning mode or in the heat pump mode, wherein the valves (16) of the pre-outlets (3) are opened and closed in the air conditioning operation to generate cold, and wherein the valves of the pre-outlets (3) remain closed in heat pump operation to generate heat.

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