Scroll compressor with intermediate chamber for the expansion of a medium previously compressed in the scroll compressor

Abstract

Scroll compressor (1; 100), comprising - a first spiral element (2) having a first wall (3), - a second spiral element (4) engaging with the first spiral element (2), which is movable relative to the first spiral element (2) and which has a second wall (5), wherein the first spiral element (2) changes its direction of travel within the first spiral element (2), and the second spiral element (4) within the second spiral element (4) changes its direction of travel, such that a first intermediate chamber (12) is formed between the first spiral element (2) and the second spiral element (4), wherein a medium (15) previously compressed in the scroll compressor (1; 100) can be released in the first intermediate chamber (12).

Description

[0001] The invention relates to a scroll compressor having an intermediate chamber in which a medium previously compressed in the scroll compressor can be released and to a method for operating this scroll compressor.

[0002] In industry, scroll compressors are used to compress working fluids and refrigerants. A working fluid flows in as a vapor at low pressure and temperature on the inlet side. Inside a scroll compressor, a movable spiral rotates against a stationary spiral. The movable spiral is subject to eccentric rotation. As a result, the working fluid experiences a narrowing of the working space in several chambers, which is continuously reduced in size.

[0003] WO 2022 / 202092 A1 shows a scroll compressor with a casing and a compression mechanism. The compression mechanism includes a compression chamber. The casing includes an intermediate pressure chamber into which a refrigerant at an intermediate pressure is introduced from an external refrigerant circuit.

[0004] DE 11 2010 002 770 T5 discloses a machine comprising two spiral casings performing a relative orbital motion, wherein one of the spiral casings is equipped with at least one spiral and the other spiral casing is equipped with at least two spirals, wherein the different spirals define a first series of chambers with variable volume belonging to a first compression or expansion stage and a second series of chambers with variable volume belonging to a second compression or expansion stage.

[0005] DE 101 03 775 A1 relates to a method for compressing a compressible medium, in which at least two displacement elements, each having at least one boundary surface with a spiral cross-section, are orbited relative to each other and form at least one chamber, wherein the volume of the chamber is changed by the orbiting movement and thereby goes through a cycle with a suction, a compression and an ejection phase, wherein the chamber is opened during the suction phase and forms a suction space.

[0006] DE 20 2022 103 517 U1 discloses a scroll compressor comprising, among other things: a compressor housing having a lower section, a first intermediate cap, a second intermediate cap and an upper section; a rotating scroll element and a non-rotating scroll element arranged inside the compressor housing and interlocking to form a compression chamber; a discharge pressure chamber arranged between the second intermediate cap and the upper section, which is configured to receive a discharge pressure fluid from the compression chamber via a compression chamber discharge port; and an intermediate pressure chamber arranged between the first intermediate cap and the second intermediate cap, which fluidly connects an intermediate pressure fluid inlet and an intermediate pressure fluid injection port of the non-rotating scroll element.

[0007] US Patent 2002 / 0 081 224 A1 discloses a scroll compressor for achieving a complete 0% capacity operating state without the use of an electromagnetic clutch. To minimize power loss, a compliant crankshaft mechanism is arranged between a shaft and a scroll element, enabling stepless adjustment of the rotating radius of the movable scroll element to zero.

[0008] During compression in a scroll compressor, fluid is often produced, which can damage the compressor. The fluid generated during compression or its return can dilute the lubricant, potentially leading to lubrication failure.

[0009] The purpose of the invention was to provide a solution to this problem.

[0010] The problem is solved with a scroll compressor and a method according to the independent claims. Preferred embodiments of the general scroll compressor or method are specified in the dependent claims and this description.

[0011] The invention describes a scroll compressor comprising - a first spiral element that has a first wall, - a second spiral element engaging with the first spiral element, which is movable relative to the first spiral element and which has a second wall, where the first spiral element within the first spiral element changes its direction of travel, and the second spiral element within the second spiral element changes its direction of travel, so that a first intermediate chamber is formed between the first spiral element and the second spiral element, in which a medium previously compressed in the scroll compressor can be released.

[0012] The intermediate chamber allows the medium to expand before it is further compressed. This is why the scroll compressor is also called a two-stage scroll compressor.

[0013] The invention also specifies a scroll compressor comprising - a first spiral element that has a first wall, - a second spiral element engaging with the first spiral element, which is movable relative to the first spiral element and which has a second wall, where the first spiral element within the first spiral element changes its direction of travel at least twice, and the second spiral element within the second spiral element changes its direction of travel at least twice, so that at least two intermediate chambers are formed between the first spiral element and the second spiral element, in which a medium previously compressed in the scroll compressor can be released.

[0014] If the scroll compressor has several intermediate chambers, it is also called a multi-stage scroll compressor.

[0015] In a more specific embodiment, a scroll compressor is specified, comprising - a first spiral element that has a first wall, - a second spiral element engaging with the first spiral element, which is relative to the first spiral element is movable, and which has a second wall, wherein the first wall has: - a first spiral section of the first wall, in which the first wall runs spirally in a first direction, - a first curved section of the first wall, in which the direction of the first wall reverses, - a second spiral section of the first wall, in which the first wall spirals in a second direction that is opposite to the first direction the second wall has: - a first spiral section of the second wall, in which the second wall runs spirally in the first direction of travel, - a first curved section of the second wall, in which the direction of the second wall reverses, - a second spiral section of the second wall, in which the second wall runs spirally in the second direction of travel, wherein, starting from the first curved section of the second wall, a first intermediate chamber is formed between a section of the first spiral section of the second wall adjoining the first curved section of the second wall and a section of the second spiral section of the second wall adjoining the first curved section of the second wall, wherein a medium previously compressed in the scroll compressor can be released in the first intermediate chamber.

[0016] The scroll compressor may also include elements commonly found in scroll compressors. These include, but are not limited to, a housing, a drive shaft coupled to one of the spiral elements, a drive motor for driving the drive shaft, an inlet opening for the medium, and an outlet opening for the medium.

[0017] The second and first spiral elements are moved relative to each other such that the second spiral element moves eccentrically along a circular path relative to the first. This principle is generally known from scroll compressors. Preferably, one of the spiral elements, for example, the second spiral element, is moved relative to the other spiral element, for example, the first spiral element, while the other spiral element is stationary relative to a housing of the scroll compressor. For example, the spiral element stationary relative to the housing can be attached to the housing or formed within the housing. Conversely, the second spiral element can be stationary relative to the housing, and the first spiral element can be moved relative to the first spiral element and relative to the housing.The spiral element that is moved relative to the other spiral element, for example the first spiral element, can be driven by a drive shaft mentioned above.

[0018] The first direction of travel mentioned and the opposing second direction of travel are not directions of rotation of the first spiral element and the second spiral element relative to each other during operation of the scroll compressor, but rather indicate a direction of travel of spiral sections within a spiral element.

[0019] In the present invention, the following effect is achieved through the special design of the spiral elements: Between the first spiral section of the first wall and the first spiral section of the second wall, the medium, also referred to as the working medium, undergoes pre-compression. During this process, the pressure and temperature increase, and a liquid phase is formed.

[0020] The medium then flows into the first intermediate chamber, which is a pressure relief chamber. The pressure drops, causing the liquid to evaporate quickly. This evaporation produces a pressure relief vapor.

[0021] The medium then undergoes further compression between a second spiral section of the first wall and a second spiral section of the second wall.

[0022] In one embodiment of the invention, the first spiral element and the second spiral element interlock in such a way that - the first spiral section of the first wall and the first spiral section of the second wall interlock, - the second spiral section of the first wall and the second spiral section of the second wall interlock, - the first curve section of the first wall and the first curve section of the second wall are adjacent to each other.

[0023] The first curved section of the first wall and the first curved section of the second wall are preferably U-shaped.

[0024] The first curve section of the first wall preferably has a larger curve radius than the first curve section of the second wall.

[0025] The first curve section of the second wall preferably lies within the first curve section of the first wall.

[0026] In one embodiment, a scroll compressor is described in which the segment of the first spiral section of the second wall adjoining the first curved section of the second wall and the segment of the second spiral section adjoining the first curved section of the second wall diverge from the first curved section of the second wall, at least in a first expansion region, such that the first intermediate chamber expands in the first expansion region. This results in a particularly effective expansion of the medium. The expansion leads to an increase in volume.

[0027] The first widening area preferably borders the first curved section of the first wall. The first widening area preferably widens in the direction of the first curved section of the first wall.

[0028] In one embodiment, a scroll compressor is specified, wherein the first wall has: - a second curved section of the first wall, in which the direction of the first wall reverses again, - a third spiral section of the first wall, in which the first wall spirals again in the first direction of travel the second wall has: - a second curved section of the second wall, in which the direction of the second wall reverses again, - a third spiral section of the second wall, in which the second wall spirals again in the first direction, wherein, starting from the second curved section of the second wall, a second intermediate chamber is formed between a section of the second spiral section of the second wall adjoining the second curved section of the second wall and a The section of the third spiral section of the second wall adjoins the second curve section of the second wall. wherein in the second intermediate chamber a medium previously compressed in the scroll compressor can be released.

[0029] It is preferably provided that when the second spiral element and the first spiral element interlock, - the third spiral section of the first wall and the third spiral section of the second wall interlock, - the second curve section of the first wall and the second curve section of the second wall are adjacent to each other,

[0030] In this embodiment, the scroll compressor has several intermediate chambers as expansion spaces, which ensure the generation of expansion vapor. This results in an even more effective operation, provided that a liquid phase is again generated during further compression between the second spiral section of the first wall and the second spiral section of the second wall. The scroll compressor is a multi-stage scroll compressor.

[0031] The second curved section of the first wall and the second curved section of the second wall are preferably U-shaped.

[0032] The second curve section of the first wall preferably has a larger curve radius than the second curve section of the second wall.

[0033] The second curve section of the second wall preferably lies within the second curve section of the first wall.

[0034] In one embodiment, a scroll compressor is specified, wherein the section of the second spiral section of the second wall that adjoins the second curve section of the second wall and The section of the third spiral section of the second wall, which follows the second curve section of the second wall, diverges from the second curve section of the second wall in a second widening area, so that the second intermediate chamber widens in the second widening area.

[0035] The advantages and effects are analogous to the previously described widening of the first intermediate chamber.

[0036] The second widening area preferably borders the second curved section of the first wall. The second widening area preferably widens in the direction of the second curved section of the first wall.

[0037] In another aspect, the invention relates to a method for operating a previously described scroll compressor, comprising - eccentric movement of the second spiral element relative to the first spiral element, - Introducing a medium as a gas phase into the scroll compressor at an inlet opening, - Compressing the medium between the second spiral element and the first spiral element, whereby a liquid phase of the medium is formed in addition to the gas phase, - Relaxation of the medium in the first intermediate chamber, whereby the pressure in the first intermediate chamber decreases and the liquid phase of the medium at least partially evaporates, - Further compression of the medium after passing through the intermediate chamber between the second spiral element and the first spiral element.

[0038] In one embodiment of the aforementioned method, the medium is compressed between the first spiral section of the first wall and the first spiral section of the second wall, and further compression of the medium takes place between the second spiral section of the first wall and the second spiral section of the second wall.

[0039] In a specific embodiment, a method for operating a previously described scroll compressor is thus specified, comprising - eccentric movement of the second spiral element relative to the first spiral element, - Introducing a medium as a gas phase into the scroll compressor at an inlet opening, - Compressing the medium between the first spiral section of the first wall and the first spiral section of the second wall, whereby a liquid phase of the medium is formed in addition to the gas phase, - Relaxation of the medium in the first intermediate chamber, whereby the pressure in the first intermediate chamber decreases and the liquid phase of the medium at least partially evaporates, - Compressing the medium between the second spiral section of the first wall and the second spiral section of the second wall.

[0040] When the medium is compressed between the second spiral section of the first wall and the second spiral section of the second wall, a liquid phase (re-formed liquid phase) of the medium can be formed again.

[0041] To address this problem, the method, in a further developed embodiment, continues to feature: - Relaxation of the medium in the second intermediate chamber, whereby the pressure in the second intermediate chamber decreases and the newly formed liquid phase of the medium at least partially evaporates, - Compressing the medium between the third spiral section of the first wall and the third spiral section of the second wall.

[0042] The invention is described below with reference to exemplary embodiments. The figures shown are: Fig. 1 a scroll compressor according to the invention in a first embodiment; Fig. 2 the first spiral element of the scroll compressor Fig. 1; Fig. 3 the second spiral element of the scroll compressor Fig. 1; Fig. 4 a scroll compressor according to the invention in a further embodiment; Fig. 5 the first spiral element of the scroll compressor Fig. 4; Fig. 6 the second spiral element of the scroll compressor Fig. 4; Fig. 7 a process flow with a scroll compressor according to Fig. 1.

[0043] The hand-drawn figures do not exactly represent the ideal or real shapes of a scroll compressor according to the invention and are not to scale, but serve to illustrate the basic structure and operating principle.

[0044] Fig. Figure 1 shows the scroll compressor 1 with the first spiral element 2 and the second spiral element 4. A housing and other components, such as the drive shaft and motor, are shown. A compression chamber is formed between the first spiral element 2 and the second spiral element 4. Boundary walls, e.g., a cover or bottom, which close off the first spiral element 2 and the second spiral element 4 at a top or bottom and thus define the compression chamber, are not shown. The second spiral element 4 is moved eccentrically relative to the first spiral element 2. A medium (not shown) flows in through the inlet opening 23 and out through the outlet opening 24. The first intermediate chamber 12 is formed in the scroll compressor 1.

[0045] For better clarity, the following are included in the Fig. 2 and Fig. 3 the first spiral element 2 and the second spiral element 4 from the Fig. Shown individually.

[0046] Fig. Figure 2 shows the first spiral element 2 with the first wall 3. A first spiral segment 6 of the first wall 3 extends from the dashed auxiliary line a to the dashed auxiliary line b. These and subsequently shown auxiliary lines are not actual elements but serve only for explanation. The first spiral segment 6 of the first wall 3 runs in a first direction D1, which here is clockwise. The first direction D1 and the opposing second direction D2 are not directions of the first spiral element 2 and the second spiral element 4 relative to each other during operation of the scroll compressor, but rather represent directions of spiral segments within a spiral element.

[0047] The first spiral section 6 of the first wall 3 is followed by the first curved section 7 of the first wall 3, which extends from the dashed auxiliary line b to the dashed auxiliary line c. The U-shape of the first curved section 7 results in a change of direction.

[0048] The second spiral section 8 of the first wall 3 follows the curve section 7 of the first wall 3 and extends from the dashed auxiliary line c to the dashed auxiliary line d. The second spiral section 8 runs in the second direction D2, which is counterclockwise and thus opposite to the first direction D1.

[0049] Fig. Figure 3 shows the second spiral element 4 from the Fig. 1 with the second wall 5. A first spiral section 9 of the second wall 5 extends from the dashed auxiliary line e to the dashed auxiliary line f in the direction D1. This is followed by the first curved section 10 of the second wall 5, which extends from the dashed auxiliary line f to the dashed auxiliary line g, is U-shaped, and in which the direction D1 reverses to the direction D2. The second spiral section 11 of the second wall 5 follows the first curved section 10 and extends in the direction D2 from the dashed auxiliary line g to the dashed auxiliary line h.

[0050] Between the auxiliary lines f and i extends the segment 13 of the first spiral section 9 of the second wall 5. Between the auxiliary lines g and j extends the first segment 14 of the second spiral section 11 of the second wall 5. Between segment 13 and the first segment 14 is the Fig. The first intermediate chamber 12 shown in 1 is formed, which is in Fig. The first widening area 16 shown in Figure 3. The section 13 of the first spiral section 9 and the first section 14 of the second spiral section 11 diverge in the direction of the first curve section 10, so that the first intermediate chamber 12 widens in the first widening area 16.

[0051] Fig. Figure 4 shows another embodiment of a scroll compressor 100 with the second intermediate chamber 21. Identical reference numerals in this figure and in further figures have the same meaning as explained in the preceding figures.

[0052] For better clarity, the following are included in the Fig. 5 and Fig. 6 the first spiral element 2 and the second spiral element 4 from the Fig. 4 shown individually. The first spiral element 2 and the second spiral element 4 in the Fig. 5 and Fig. 6 are compared to the Fig. 2 and Fig. 3 were structurally modified, but were given the same reference symbol.

[0053] The following section will primarily explain the differences.

[0054] In Fig. 5 The first spiral section 6 of the first wall 3 runs in the direction of travel D1 and the second spiral section 8 of the first wall 3 runs in the direction of travel D2. In contrast to the scroll compressor 1 from the Fig. In sections 1-3, the directions D1 and D2 are reversed. The first direction D1 is counterclockwise, and the second direction D2 is clockwise. The second spiral section 8 is followed by the second curve section 17 of the first wall 3, which runs from auxiliary line d to auxiliary line k. The third spiral section 18 of the first wall 3 is followed by the second curve section 17, which runs from auxiliary line k to auxiliary line I. Due to the reversal of direction in the second curve section 17, the third spiral section 18 again runs in direction D2, like the first spiral section 6.

[0055] In Fig. 6 The first spiral section 9 of the second wall 5 runs in the direction of travel D1 and the second spiral section 11 of the second wall 5 runs in the direction of travel D2. In contrast to the scroll compressor 1 from the Fig. In sections 1-3, the directions D1 and D2 are reversed. The first direction, D1, is counterclockwise, and the second direction, D2, is clockwise.

[0056] The second spiral section 11 is followed by the second curved section 19 of the second wall 5, which runs from the auxiliary line h to the auxiliary line m. The third spiral section 20 of the second wall 5 is followed by the second curved section 19, which runs from the auxiliary line m to the auxiliary line n.

[0057] Between the auxiliary lines h and p extends the second segment 25 of the second spiral section 11 of the second wall 5. Between the auxiliary lines m and o extends segment 26 of the third spiral section 20 of the second wall 5. Between the second segment 25 and the segment 26 is the Fig. 4 shown second intermediate chamber 21 formed, which in Fig. The second widening area 22 shown in Figure 6. The second section 25 of the second spiral section 11 and the section 26 of the third spiral section 20 diverge in the direction of the second curve section 19, so that the second intermediate chamber 21 widens in the second widening area 22.

[0058] Fig. Figure 7 shows a process flow in which medium 15 is compressed.

[0059] First, the second spiral element 4 moves eccentrically relative to the first spiral element 2.

[0060] As in the Fig. As shown in the left-hand illustration, the medium 15 is introduced as a gas phase into the scroll compressor 1 at the inlet opening 23. The medium 15 is then compressed between the first spiral section 6 of the first wall 3 and the first spiral section 9 of the second wall 5 (see Figure 7). Fig. 3, which show the spiral sections). In this process, a liquid phase of the medium 15 is formed alongside the gas phase.

[0061] Fig. Figure 7 shows in the middle representation the relaxation of the medium 15 in the first intermediate chamber 12, whereby in the first intermediate chamber 1) the pressure decreases and the liquid phase of the medium 15 at least partially evaporates.

[0062] Fig. Figure 7 shows the recompression of the medium 15 between the second spiral section 8 of the first wall 3 and the second spiral section 11 of the second wall 5. The compressed medium 15 flows through the outlet 24. Reference symbol list 1 Scroll compressor 2 first spiral element 3 first wall 4 second spiral element 5 second wall 6 first spiral section of the first wall 7 first curve section of the first wall 8 second spiral section of the first wall 9 first spiral section of the second wall 10 first curve section of the second wall 11 second spiral section of the second wall 12 first intermediate chamber 13 Section of the first spiral section of the second wall 14 first section of the second spiral section of the second wall 15 Medium 16 first expansion area 17 second curve section of the first wall 18 third spiral section of the first wall 19 second curve section of the second wall 20 third spiral section of the second wall 21 second intermediate chamber 22 second expansion area 23 Entrance opening 24 Exit opening 25 second section of the second spiral section of the second wall 26 Section of the third spiral section of the second wall 100 scroll compactors D1 first direction of travel D2 second direction of travel ap guidelines

Claims

[1] Scroll compressor (1; 100), comprising - a first spiral element (2) having a first wall (3), - a second spiral element (4) engaging with the first spiral element (2), which is movable relative to the first spiral element (2) and which has a second wall (5), where the first spiral element (2) within the first spiral element (2) changes its direction of travel, and the second spiral element (4) within the second spiral element (4) changes its direction of travel, such that a first intermediate chamber (12) is formed between the first spiral element (2) and the second spiral element (4), wherein a medium (15) previously compressed in the scroll compressor (1; 100) can be released in the first intermediate chamber (12). [2] Scroll compressor (1; 100) according to claim 1, wherein the first wall (3) has: - a first spiral section (6) of the first wall (3), in which the first wall (3) runs spirally in a first direction (D1), - a first curve section (7) of the first wall (3), in which the first direction of travel (D1) of the first wall (3) reverses, - a second spiral section (8) of the first wall (3), in which the first wall (3) spirals in a second direction (D2) opposite to the first direction (D1). wherein the second wall (5) has: - a first spiral section (9) of the second wall (5), in which the second wall (5) runs spirally in the first direction of travel (D1), - a first curve section (10) of the second wall (5), in which the first direction (D1) of the second wall (5) reverses, - a second spiral section (11) of the second wall (5), in which the second wall (5) runs spirally in the second direction (D2), wherein, starting from the first curved section (10) of the second wall (5), the first intermediate chamber (12) is formed between a section (13) of the first spiral section (9) of the second wall (5) adjoining the first curved section (10) of the second wall (5) and a first section (14) of the second spiral section (11) of the second wall (5) adjoining the first curved section (10) of the second wall (5). [3] Scroll compressor (1; 100) according to claim 2, wherein the section (13) of the first spiral section (9) of the second wall (5) adjoining the first curved section (10) of the second wall (5) and the first section (14) of the second spiral section (11) of the second wall (5) adjoining the first curved section (10) of the second wall (5) diverge from the first curved section (10) of the second wall (5) at least in a first widening area (16), so that the first intermediate chamber (12) widens in the first widening area (16). [4] Scroll compressor (100) according to claim 2 or 3, wherein the first wall (3) has: - a second curved section (17) of the first wall (3), in which the second direction of travel (D2) of the first wall (3) reverses, - a third spiral section (18) of the first wall (3), in which the first wall (3) spirals again in the first direction (D1). wherein the second wall (5) has: - a second curve section (19) of the second wall (5), in which the second direction of travel (D2) of the second wall (5) reverses, - a third spiral section (20) of the second wall (5), in which the second wall (5) spirals again in the first direction (D1), wherein starting from the second curved section (19) of the second wall (5) a second intermediate chamber (21) is formed between a second section (25) of the second spiral section (11) of the second wall (5) adjoining the second curved section (19) of the second wall (5) and a section (26) of the third spiral section (20) of the second wall (5) adjoining the second curved section (19) of the second wall (5), wherein in the second intermediate chamber (21) a medium (15) previously compressed in the scroll compressor (100) can be relaxed. [5] Scroll compressor (100) according to claim 4, wherein the second section (21) of the second spiral section (11) of the second wall (5) adjoining the second curved section (19) of the second wall (5) and the section (26) of the third spiral section (20) of the second wall (5) adjoining the second curved section (19) of the second wall (5) diverge from the second curved section (19) of the second wall (5) in a second expansion area (22), so that the second intermediate chamber (21) expands in the second expansion area. [6] Method for operating a scroll compressor as described in any one of claims 1-5, comprising - eccentric movement of the second spiral element (4) relative to the first spiral element (2), - Introducing a medium (15) as a gas phase into the scroll compressor at an inlet opening (23), - Compressing the medium (15) between the second spiral element (4) and the first spiral element (2), whereby a liquid phase of the medium (15) is formed in addition to the gas phase, - Relaxation of the medium (15) in the first intermediate chamber (12), whereby the pressure in the first intermediate chamber (12) decreases and the liquid phase of the medium (15) at least partially evaporates, - Further compression of the medium (15) after passing through the intermediate chamber (12) between the second spiral element (4) and the first spiral element (2). [7] Method for operating a scroll compressor according to claim 6, wherein the compression of the medium (15) takes place between the first spiral section (6) of the first wall (3) and the first spiral section (9) of the second wall (5), and the further compression of the medium (15) takes place between the second spiral section (8) of the first wall (3) and the second spiral section (11) of the second wall (5).

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