Refrigerant compressor for an air conditioning system and method of operating a refrigerant compressor

Abstract

To provide a refrigerant compressor for an air conditioning system and a method for operating the refrigerant compressor, which ensures safe functional implementation of the refrigerant compressor and reduces the effort and cost required for producing the refrigerant compressor. [Problem] [Solution] The present invention provides a refrigerant compressor (1) for an air conditioning system, in which a filter is disposed in a front region of a spiral nozzle insert portion (4) of the refrigerant compressor (1) to prevent clogging of the refrigerant compressor (1) when viewed from the direction of the refrigerant mass flow (12) of the refrigerant compressor (1), An annular channel (6) surrounding a molded portion (8) is disposed in the central housing of the refrigerant compressor (1), the molded portion (8) including a circular ring-shaped flat surface (9); The friction plate (10) is arranged parallel to the circular ring-shaped plane (9), A gap (11) acting as a filter is formed between the circular ring-shaped flat surface (9) and the friction plate (10), and the annular channel (6) is connected to the inlet (7) for the refrigerant of the refrigerant compressor (1) through a side chamber (14).

Description

[Technical Field]

[0001] The present invention relates to a refrigerant compressor for an air conditioning system and a method for operating a refrigerant compressor, and more particularly to an electric refrigerant compressor for an air conditioning system in which a filter is disposed in a region in front of a spiral nozzle insert of the refrigerant compressor when viewed from the direction of refrigerant flow in the refrigerant compressor in order to prevent clogging of the refrigerant compressor.

[0002] The present invention also relates to a method of operating a refrigerant compressor in which particles exceeding a predefined size are filtered in the area in front of the spiral nozzle insert of the refrigerant compressor when viewed in the direction of refrigerant flow in the refrigerant compressor. [Background technology]

[0003] It is known from the prior art that so-called air conditioning compressors or electric refrigerant compressors driven by electric motors are used in air-conditioned vehicles, which also apply in particular to electric or at least partially electric drive vehicles, such as vehicles with electric or hybrid drives.

[0004] In particular, the above relates to electric refrigerant compressors for vehicle air conditioning systems, in which filters are used to prevent clogging, particularly in the forward region of the spiral nozzle insert or spiral nozzle of the refrigerant compressor, when viewed from the direction of refrigerant flow in the refrigerant compressor.

[0005] It is known from the prior art that a back pressure after the orbiting scroll is necessary for the proper operation of the electric refrigerant compressor. Such back pressure is generated by the refrigerant mass flow, which is regulated by a control valve associated with the helical nozzle insert and the helical nozzle. The helical nozzle has a reduced cross section or diameter, resulting in the risk of refrigerant particles clogging the helical nozzle insert or the helical nozzle. Such clogging reduces the efficiency of the refrigerant compressor and can lead to malfunctions.

[0006] Patent Document 1 discloses a scroll compressor particularly for use in motor vehicle air conditioning systems. The disclosed content is a scroll compressor equipped with an oil recirculation unit having a fixed scroll and an orbiting scroll, where gas is drawn in from a low-pressure space between the two scrolls, compressed, and transferred to a high-pressure space. Furthermore, to minimize friction as much as possible through force balance and allow the orbiting scroll to move within the fixed scroll, a counter-pressure space is formed that pressurizes the orbiting scroll toward the fixed scroll.

[0007] Also disclosed is a low-pressure helical nozzle formed from a cylindrical cavity in a central housing, preferably a cavity designed as a cylindrical bore. A helical nozzle insert is disposed in the cylindrical cavity. The helical nozzle insert communicates with the wall of the cylindrical cavity such that a helical nozzle is formed between the wall of the cylindrical cavity and the surface of the helical nozzle insert. The surface of the helical nozzle insert preferably has helical grooves, also called coils, that form a helical throttle channel in the area where the helical nozzle insert contacts the wall of the cylindrical cavity.

[0008] Scroll compressors with helical nozzle inserts are therefore known from the prior art, and it is also known in such refrigerant compressors to place a filter in the mass flow area in front of the helical nozzle or in front of the helical nozzle insert to filter particles that clog the nozzle.

[0009] According to the prior art, it is known to use filters in compressor systems for filtering particles that clog the helical nozzle inserts or the helical nozzles, for example with a typical mesh size of 125 μm.

[0010] The use of such an additional filter requires additional installation space, at least one additional assembly step to place the filter, and therefore additional costs to the production of the electric refrigerant compressor.

[0011] Therefore, there is a need for improved refrigerant compressors for air conditioning systems and improved methods of operating refrigerant compressors. [Prior art documents] [Patent documents]

[0012] [Patent Document 1] German Patent Application Publication No. 102019101855 Summary of the Invention [Problem to be solved by the invention]

[0013] An object of the present invention is to provide a refrigerant compressor for an air conditioning system and a method for operating the refrigerant compressor, which can ensure safe functioning of the refrigerant compressor and reduce the effort and cost required for manufacturing the refrigerant compressor. [Means for solving the problem]

[0014] The present invention provides a refrigerant compressor for an air conditioning system, in which a filter is disposed in a front region of a spiral nozzle insertion portion of the refrigerant compressor to prevent clogging of the refrigerant compressor when viewed from the mass flow direction of the refrigerant in the refrigerant compressor, comprising: an annular channel surrounding the molding is disposed in a central housing of the refrigerant compressor; the molded portion includes a circular ring-shaped flat surface; The friction plate is arranged parallel to the circular ring-shaped plane, A gap that acts as a filter is formed between the circular ring-shaped flat surface and the friction plate.

[0015] The present invention also provides a method for operating a refrigerant compressor, in which particles exceeding a predetermined size are filtered in a front region of a spiral nozzle insert of the refrigerant compressor when viewed from a mass flow direction of the refrigerant, comprising: an annular channel surrounding the molding is provided in a central housing of the refrigerant compressor; The molding is provided with a circular ring-shaped flat surface; A friction plate is provided parallel to the circular ring-shaped plane, As a result, a filter for filtering particles exceeding a predetermined size is formed by the gap between the circular ring-shaped plane and the friction plate.

[0016] A gap or gap filter having a defined geometric pattern and defined dimensions, which must be formed in the housing of the refrigerant compressor or in the central housing of the refrigerant compressor, is provided so as to be formed in the front region of the spiral nozzle insert or nozzle to be protected when viewed from the direction of refrigerant flow.

[0017] To this end, a gap or gap filter is provided between a housing portion of the refrigerant compressor, such as a center housing, and a friction plate disposed on the housing portion. Due to the arrangement of the friction plates, a gap according to the present invention is formed on one side, and the refrigerant compressor housing is sealed on the other side, preventing refrigerant from escaping from the refrigerant compressor. The friction plates can also be replaced, and in this manner, the refrigerant compressor can be repaired or adjusted to meet changed operating conditions, if necessary.

[0018] Due to its specific contour and defined dimensions, the gap or gap filter allows for filtering of particle sizes that would normally clog a spiral nozzle insert or spiral nozzle. As a result, a separate filter, as in the prior art, placed in front of the spiral nozzle insert or spiral nozzle in the refrigerant mass flow is no longer necessary. For simplicity, only the term "gap" forming the gap filter will be used below.

[0019] The gap size is defined so that it is large enough to filter out particles of the size that typically cause the aforementioned clogging while avoiding or only insignificantly affecting the mass flow of the refrigerant. The gap thus formed only insignificantly increases the refrigeration resistance of the flowing refrigerant, so no changes are required to the basic design or dimensions of existing refrigerant compressors. The design must be adjusted only in the area of ​​the refrigerant compressor housing where the friction plates are located.

[0020] The gap is formed in a ring shape from the inlet region of the spiral nozzle insert through the annular forming portion of the central housing of the refrigerant compressor and the friction plate. The annular gap is disposed around the central axis of the bore for the spiral nozzle, and has an inner diameter that is the same as or larger than the diameter of the bore for the spiral nozzle.

[0021] The housing section or central housing in which the bore for the spiral nozzle is located has an annular shaped section surrounding the bore, the shaped section having a trapezoidal or rectangular cross section. The area of ​​the annular shaped section, which is a circular ring-shaped plane, forms a gap with a filtering effect through the friction plate parallel to the circular ring-shaped plane. The friction plate is also flat, at least in the area opposite and parallel to the circular ring-shaped plane.

[0022] In particular, the gap formed between the circular ring-shaped plane of the molding and the friction plate is provided to have a size in the range between 0.1 mm and 0.2 mm, particularly in the range between 0.04 mm and 0.16 mm.

[0023] The inner diameter of the circular ring-shaped plane of the molding part is provided to be in the range between 6 mm and 12 mm. The difference between the inner diameter of the circular ring-shaped plane of the molding part and the outer diameter of the circular ring-shaped plane of the molding part, also called the width of the circular ring-shaped plane, is provided to be in the range between 1 mm and 3 mm.

[0024] Such gap dimensioning allows for filtering of particle sizes that would typically clog a spiral nozzle insert or spiral nozzle, while also avoiding excessive reduction in the mass flow of refrigerant through the gap due to gap clogging.

[0025] Gap clogging refers to the accumulation of particles in the gap that cannot pass through the gap due to the size of the gap, this accumulation being consistent with filtered particles that filters designed according to the prior art would filter.

[0026] In actual experiments, gap dimensions of 8 mm inner diameter of the circular ring flat, 11 mm outer diameter of the circular ring flat, and 0.15 mm gap size have a significant effect on the refrigerant mass flow of the refrigerant compressor with only a gap plugging rate of 90% or more. The refrigerant mass flow through the gap and the functional operation of the electric refrigerant compressor are therefore not affected or only slightly affected with gap plugging up to about 90%.

[0027] The inventive design of the gap is made possible by utilizing an annular channel to direct the coolant flow around the shaped portion that forms the gap, thus providing sufficient filter space or area so that partial blockage of the gap does not affect the coolant mass flow.

[0028] The most uniform peripheral mass flow of the incoming coolant is created within the annular panel, providing uniform flow on all sides around the annular channel and molding. To this end, the incoming coolant flows through an inlet into a side chamber that is partially fluidly connected to the annular channel. In this side chamber, the coolant flows through a transition region into the annular channel. This transition region, which extends over a circularly divided section of the annular channel within, for example, a 60- to 100-degree angle, allows for improved uniformity of the coolant flow into the annular channel over a wider area than coolant directly supplied to the annular channel through the inlet.

[0029] The indirect entry of the coolant into the annular channel through the side chambers and a transition area of ​​this size reduces turbulence in the coolant mass flow that occurs at small openings and / or corners.

[0030] The inventive embodiment of the gap with filtering effect requires significantly less installation space and does not require additional components such as filters, thereby simplifying the assembly of the electric refrigerant compressor and reducing the production costs of the electric refrigerant compressor. [Brief explanation of the drawings]

[0031] Additional details, features and advantages of embodiments of the present invention are described in the following description of exemplary embodiments, with reference to the associated drawings, in which: [Figure 1] FIG. 2 is a detailed cross-sectional view of the area where a gap or gap filter is formed in the refrigerant compressor. [Figure 2] FIG. 2 is a detailed view of an area where a gap or gap filter is formed, seen from above a molding section for forming a gap in a refrigerant compressor. [Figure 3] FIG. 1 is a cross-sectional view of a bore for a helical nozzle insert of a refrigerant compressor with a gap or gap filter formed on the inlet side. [Figure 4] 1 is an exemplary dimension of a bore and gap or gap filter for a helical nozzle insert of a refrigerant compressor. [Figure 5] 1 is a graph showing the mass flow of refrigerant through a gap or gap filter acting as a gap plug; DETAILED DESCRIPTION OF THE INVENTION

[0032] FIG. 1 illustrates a detailed cross-sectional view of the area in the refrigerant compressor (1) where the gap (11) or gap filter is formed.

[0033] Figure 1 illustrates a refrigerant compressor (1) with a portion of a central housing (2) that defines a cylindrical bore (3) into which a spiral nozzle insert (4) with a coil is inserted. The central housing (2) includes an annular channel (6) surrounding the bore (3) and connected to an inlet (7) (not shown in Figure 1).

[0034] In the central housing (2), between the annular channel (6) and the bore (3) for the helical nozzle insert (4), a molding (8) is formed surrounding the bore (3), the molding having a trapezoidal or rectangular cross section. Such an area of ​​the molding (8) in the central housing (2) is illustrated in Figure 1 by a dotted line.

[0035] The gap (11) or gap filter according to the present invention is formed between the friction plate (10) closing the refrigerant compressor (1) and the circular ring-shaped flat surface (9) of the molding part (8). For this purpose, the trapezoidal or rectangular molding part (8) in the central housing (2) is designed so that a space ranging from 0.04 mm to 0.16 mm is formed between the circular ring-shaped flat surface (9) of the molding part (8) and the friction plate (10).

[0036] The refrigerant entering the annular channel (6) through the inlet (7) passes through the gap (11) and travels through the bore (3) to the spiral nozzle insert (4). The mass flow (12) of the refrigerant is illustrated in Figure 1 using a number of arrows.

[0037] Due to the gap (11) having the size and shape according to the invention, particles exceeding a predefined size are filtered out as they cannot pass through the gap (11) and enter the area of ​​the spiral nozzle insert (4).

[0038] Such particles are therefore prevented from clogging the spiral nozzle insert area with the nozzle, which in the prior art was possible by utilizing a separate filter with a coarse mesh.

[0039] Figure 2 shows a detailed view of the area where the gap (11) (see Figure 1) or gap filter is formed in the refrigerant compressor (1). Figure 2 is a view from above of the ring-shaped forming part (8) that protrudes to form the gap with the friction plate (10) removed.

[0040] FIG. 2 illustrates a central housing having a cylindrical bore (3) in which a helical nozzle insert (4) with a coil (5) is placed. Also shown is an annular channel (6) which extends along a circle around the bore (3) and is at least indirectly connected to an inlet (7) for the coolant.

[0041] The most uniform peripheral mass flow of the incoming coolant is created within the annular panel, providing uniform flow on all sides around the annular channel and molding. To this end, the incoming coolant initially flows through the inlet (7) into a side chamber (14) that is partially fluidly connected to the annular channel (6). From this side chamber (14), the coolant flows into the annular channel (6) through a transition region (15). Such a transition region, which extends over a circularly divided section of the annular channel (6) within a range of, for example, 60 to 100 degrees, allows for improved uniformity of the coolant flow over a wider area into the annular channel (6) compared to coolant directly supplied to the annular channel (6) through the inlet (7). The transition region (15) is indicated by a dashed line in FIG. 2.

[0042] The indirect entry of the coolant into the annular channel (6) through the side chamber (14) and the transition area of ​​this size reduces turbulence in the coolant mass flow (12) that occurs at small openings and / or corners.

[0043] Also shown in the top view shown in Figure 2 is the circular surface (9) for forming the gap (11), which is part of the molding (8) in the central housing (2) of the refrigerant compressor (1).

[0044] The arrows indicate the mass flow (12) of refrigerant from the inlet (7) through the annular channel (6) and several points in the annular gap (11) towards the helical nozzle insert (4) with coil (5).

[0045] FIG. 3 illustrates a cross-sectional view of a bore (3) for a spiral nozzle insert (4) of a refrigerant compressor (1) in which a gap (11) or gap filter is formed on the inlet side.

[0046] By inlet side, it is meant that the gap is formed in the region where the mass flow of coolant (12) passes through the gap (11) from the annular channel (6) to the inlet region of the spiral nozzle insert (4).

[0047] Figure 3 also illustrates a friction plate (10) attached to the central housing (2) of the refrigerant compressor (1). It can be seen that a gap (11) is formed between the molding (8) of the central housing (2) and this friction plate (10).

[0048] 3 also shows the inlet 7 through which the refrigerant flows inside the annular channel 6 and the side chamber 14 connected to the annular channel 6. In the area of ​​the inlet 7, "BP" stands for back pressure.

[0049] The refrigerant filtered through the gap (11) or gap filter flows through the coils (5) of the spiral nozzle insert (4) toward the nozzle profile end (13) shown in the lower portion of the spiral nozzle insert (4) in Figure 3. Again, the mass flow (12) in this region is illustrated, for example, using two arrows. In the region of the nozzle profile end (13), "LP" stands for low pressure.

[0050] As is common in the prior art, the helical nozzle insert (4) can have a thin bore in the region of the central axis, as shown in the example of FIG.

[0051] FIG. 4 illustrates a detailed view of the central housing (2) of the refrigerant compressor (1) in the area of ​​the bore (3) and gap (11) or gap filter for the helical nozzle insert (4) using exemplary dimensions.

[0052] In Figure 4, the refrigerant mass flow (12) in the refrigerant compressor (1) is similarly illustrated using arrows. The refrigerant flows into the annular channel (6) through the inlet (7) and side chamber (14). In the example of Figure 4, the annular channel (6) has an inner diameter of 11 mm and a channel width of 2.3 mm, with the channel width being larger in the inlet (7) region. The height of the ring-shaped annular channel (6) is indicated, for example, as 1 mm.

[0053] From this annular channel 6, the refrigerant flows through an annular gap 11 to the spiral nozzle insert 4 with a coil. In the illustrated example, the gap 11 formed between the molded portion 8 and the friction plate 10 has a width of 0.15 mm. In Figure 4, the pedestal molded portion 8 of the center housing 2 is indicated, for example, by a dotted line.

[0054] In the example of FIG. 4, a helical nozzle insert (4) with a coil (5) flows inside a bore (3) with a diameter of 8 mm, having a thin bore as already known from FIG.

[0055] FIG. 5 illustrates a graph showing the mass flow of refrigerant through a gap (11) or gap filter that functions as a gap plug.

[0056] In the graph of Figure 5, the constant gap clogging rate (Rs) in percent (%) is plotted on the abscissa or x-axis. Gap clogging refers to the accumulation of particles in the gap (11) that, due to the size of the gap, prevents particles from passing through the gap (11). Such particle accumulation corresponds to the filtered particles that filters designed according to the prior art would filter.

[0057] In the graph of FIG. 5, the sump flow rate qm or mass flow of the refrigerant flowing through the gap (11) expressed in kg / h (kilograms per hour) is plotted on the ordinate or y-axis.

[0058] The graphic in FIG. 5 illustrates the refrigerant mass flow or volumetric flow rate qm curve with the gap plugging RS function.

[0059] As previously mentioned, the accumulation of particles exceeding a predefined size in the gap (11) will have no or only a minor effect as long as such gap clogging Rs effect is maintained below a 90% ratio or value.

[0060] The refrigerant sump flow rate qm, which is approximately 1.91 kg / h in the example of Figure 5, therefore remains practically constant within the gap blockage range of 0% to 90%. Functional operation of the electric refrigerant compressor (1) and prevention of blockage by particles exceeding a predefined size are therefore guaranteed within said range.

[0061] Only when the gap clogging rate Rs exceeds 90% does a decrease in the refrigerant stagnation flow rate qm occur, which can have a negative impact on the operation of the electric refrigerant compressor 1. Therefore, when the gap clogging rate Rs is about 95%, the refrigerant stagnation flow rate qm decreases to about 1.85 kg / h, which corresponds to a decrease of about 3% in the refrigerant stagnation flow rate qm. When the gap clogging rate Rs is about 98%, the refrigerant stagnation flow rate qm decreases to about 1.6 kg / h, which corresponds to a decrease of about 16% in the refrigerant stagnation flow rate qm.

[0062] The drawing shows that the safe operation or functional safety of the gap filter according to the invention formed by the gap (11) is ensured over a very wide range of gap clogging Rs. [Explanation of symbols]

[0063] 1 Refrigerant compressor 2 Center Housing 3 Bore 4 Spiral nozzle insert 5 Coil 6 Annular channel 7 Inlet part 8 Forming part 9 Circular ring type surface 10 Friction plate 11 Gap 12 Mass flow 13 Nozzle type end 14 Side chamber 15 Transition region

Claims

1. A refrigerant compressor (1) for an air conditioning system, in which a filter is arranged in a front region of a spiral nozzle insert (4) of the refrigerant compressor (1) to prevent clogging of the refrigerant compressor (1) when viewed from the direction of refrigerant mass flow (12) of the refrigerant compressor (1), is An annular channel (6) surrounding a molded portion (8) is disposed in the central housing of the refrigerant compressor (1), The molding (8) includes a circular ring-shaped plane (9), The friction plate (10) is arranged parallel to the circular ring-shaped plane (9), A refrigerant compressor characterized in that a gap (11) acting as a filter is formed between the circular ring-shaped flat surface (9) and the friction plate (10).

2. 2. The refrigerant compressor according to claim 1, wherein the annular channel (6) is connected to an inlet (7) for the refrigerant of the refrigerant compressor (1) through a side chamber (14).

3. 3. The refrigerant compressor according to claim 1, wherein the bore (3) in which the spiral nozzle insert (4) is located is located within the molding (8) in the central housing (2) of the refrigerant compressor (1).

4. 2. A refrigerant compressor according to claim 1, characterized in that the shaped portion (8) has a trapezoidal or rectangular cross section.

5. Refrigerant compressor according to claim 1, characterized in that the size of said gap (11) ranges between 0.1 mm and 0.2 mm.

6. the inner diameter of the circular ring-shaped plane (9) of the molding (8) is in the range between 6 mm and 12 mm; 2. A refrigerant compressor according to claim 1, characterized in that the width of the circular ring-shaped plane (9) of the shaping (8) is in the range between 1 mm and 3 mm.

7. A method of operating a refrigerant compressor (1) in which particles exceeding a predefined size are filtered in a front area of ​​a spiral nozzle insert (4) of the refrigerant compressor (1) when viewed in the direction of the refrigerant mass flow (12) of the refrigerant compressor, comprising: An annular channel (6) surrounding a molded portion (8) is provided in the central housing (2) of the refrigerant compressor (1), The molding (8) is provided with a circular ring-shaped plane (9), A friction plate (10) is provided parallel to the circular ring-shaped plane (9), As a result, a filter for filtering particles exceeding a predefined size is formed by the gap between the circular ring-shaped plane (9) and the friction plate (10).

8. A mass flow (12) of the coolant is carried out through a side chamber (14) having an inlet (7), said mass flow (12) passing through said inlet (7) and inside said annular channel (6) through said gap (11) towards a spiral nozzle insert (4) provided in said bore (3); 8. The method according to claim 7, characterized in that particles exceeding a predefined size are filtered into the gap (11) and therefore cannot reach the front region of the helical nozzle insert (4).

9. 9. A method according to claim 7 or 8, characterized in that the gap (11) is provided with a size between 0.1 mm and 0.2 mm.

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