Refrigerant compressor with a resonator downstream of a volute
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- DANFOSS AS
- Filing Date
- 2024-11-26
- Publication Date
- 2026-06-25
AI Technical Summary
Centrifugal refrigerant compressors generate significant acoustic noise during the discharge flow, which can lead to inefficiencies and increased operational costs in chiller systems.
The implementation of a resonator positioned near the discharge opening of the volute, featuring a series of plates with differently sized openings, creates quarter wave tubes that attenuate specific acoustic frequencies, thereby reducing noise levels.
This configuration effectively decreases the acoustic noise in the discharge flow by at least 11 dB across specific frequency ranges, enhancing the operational efficiency and reducing costs associated with noise-related issues.
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Figure EP2024083672_25062026_PF_FP_ABST
Abstract
Description
ACOUSTIC RESONATORS CROSS-REFERENCED TO RELATED APPLICATION
[0001] This application claims priority to U.S. Provisional Application No. 63 / 611,968, which was filed on December 19, 2023. BACKGROUND
[0002] Refrigerant compressors are used to circulate refrigerant in a chiller via a refrigerant loop. Refrigerant loops are known to include a condenser, an expansion device, and an evaporator. The compressor compresses the fluid, which then travels to a condenser, which in turn cools and condenses the fluid. The refrigerant then goes to an expansion device, which decreases the pressure of the fluid, and to the evaporator, where the fluid is vaporized, completing a refrigeration cycle.
[0003] Many refrigerant compressors are centrifugal compressors and have an electric motor that drives at least one impeller to compress refrigerant. Fluid flows into the impeller in an axial direction, and is expelled radially from the impeller. The fluid is then directed downstream for use in the chiller system. SUMMARY
[0004] In some aspects, the techniques described herein relate to a refrigerant compressor, including: a volute; and a resonator positioned near a discharge opening of the volute. The resonator includes a pipe including an inlet; and a plurality of plates positioned near the inlet. A first one of the plurality of plates includes a first opening, and a second one of the plurality of plates includes a second opening sized differently from the first opening.
[0005] In implementations, a third one of the plurality of plates includes a third opening.
[0006] In implementations, the first one of the plurality of plates has a first thickness and the second one of the plurality of plates has a second thickness different from the first thickness.
[0007] In implementations, the pipe provides a shelf, and the first one of the plurality of plates is received against the shelf.
[0008] In implementations, the pipe is positioned on a center axis, and the plurality of plates are concentric with the pipe relative to the center axis.
[0009] In some aspects, the techniques described herein relate to a refrigerant compressor, including a flow splitter disposed at the inlet.
[0010] In implementations, the first opening and the second opening are circular through holes.
[0011] In implementations, the pipe is positioned on a center axis, and the plurality of plates are concentric with the pipe relative to the center axis.
[0012] In implementations, the first opening and the second opening are concentric about a second axis.
[0013] In some aspects, the techniques described herein relate to a refrigerant compressor, including a retainer received against plurality of plates including a retainer opening.
[0014] In implementations, a diameter of the retainer opening increases as the retainer opening extends away from the plurality of plates.
[0015] In implementations, the first opening is one of a first group of four openings in the first one of the plurality of plates, and the second opening is one of a second group of four openings in the second one of the plurality of plates.
[0016] In implementations, the first opening is one of a first group of four openings in the first one of the plurality of plates, and the second opening is one of a second group of four openings in the second one of the plurality of plates.
[0017] In implementations, each of the first group of four openings at least partially overlaps with a respective one of the second group of four openings.
[0018] In implementations, the first one of the plurality of plates has a first thickness and the second one of the plurality of plates has a second thickness different from the first thickness.
[0019] In implementations, the first one of the plurality of plates is received against the second one of the plurality of plates.
[0020] In implementations, a third one of the plurality of plates includes a third opening and is downstream of the first and second ones of the plurality of plates, the third opening having a greater cross-sectional area than each of the first and second openings.
[0021] In implementations, the first, second, and third openings are each circular through holes concentric about an axis.
[0022] In implementations, the third one of the plurality of plates has a different thickness from at least one of the first and second ones of the plurality of plates. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Figure 1 schematically illustrates an example refrigerant system.
[0024] Figure 2 illustrates an example compressor
[0025] Figure 3 illustrates an example resonator
[0026] Figure 4 illustrates an example plate of the example resonator.
[0027] Figure 5 illustrates another example plate.
[0028] Figure 6 illustrates the example resonator received at the discharge opening.
[0029] Figure 7 schematically illustrates the flow of refrigerant through the example resonator.
[0030] Figure 8 illustrates a fluid domain of the example resonator.
[0031] Figure 9 illustrates adjacent example plates.
[0032] Figure 10 illustrates an example noise attenuation simulation result of an example resonator. DETAILED DESCRIPTION
[0033] This disclosure relates generally to refrigerant compressors, and more specifically to resonators for discharge flow of centrifugal refrigerant compressors.
[0034] Figure 1 illustrates a refrigerant system 10. The refrigerant system 10 includes a main refrigerant loop, or circuit, 12 in communication with a compressor 14, a condenser 16, an evaporator 18, and an expansion device 20. This refrigerant system 10 may be used in a chiller, for example. In that example, a cooling tower may be in fluid communication with the condenser 16. While a particular example of the refrigerant system 10 is shown, this application extends to other refrigerant system configurations, including configurations that do not include a chiller. For instance, the main refrigerant loop 12 can include an economizer downstream of the condenser 16 and upstream of the expansion device 20.
[0035] Figure 2 illustrates an example compressor 14 including a volute 20 and an outer housing 22 adjacent the volute 20. One or both of the volute 20 and the housing 22 may provide a volute discharge opening 24 where refrigerant exits the compressor 14.
[0036] Figure 3 illustrates an example resonator 26 that may be positioned near the discharge opening 24 to receive refrigerant exiting the compressor 14. In some examples, the resonator 26 may be attached to the housing 22. The resonator 26 may include an outer pipe 28 providing a through opening 30. In some examples, the pipe 28 is a hollow cylinder and the opening 30 is provided radially inward of the the inner diameter of the hollow cylinder. An inlet end 32 of the resonator may be positioned nearest the discharge opening 24 (not shown).
[0037] One or more plates 34 may be positioned within the opening 30. The outer pipe may be centered on a central longitudinal axis 36, and the pipe 28 and the plates 34 may be concentric about the axis 36. A plate 34 may include one or more openings 38. A flow splitter 40 may be provided at the inlet end 32 to direct flow into the openings 38. In some examples, as shown, the flow splitter 40 may be tapered. In some examples, as shown, the flow splitter 40 may be cone-shaped and centered on the axis 36. As shown, the base of the cone of the flow splitter 40 may abut the plate 34 nearest the inlet end 32, and the cone tapers as it extends away from the plate 34. The openings 38 may be radially outward of the flow splitter 40 with respect to the axis 36.
[0038] Figure 4 illustrates an example plate 34 including openings 38. In the example shown, four circular through holes are provided. As shown the centers of adjacent openings 38 may be spaced 90 degrees from one another. More or fewer openings 38 may be utilized in some examples. Other shapes of openings 38 may be utilized in some examples. As will be explained further, the size of openings 38 may be varied across adjacent plates within the resonator 26. The openings 38 of a plate 34 may be sized the same as one another as shown. In some examples, openings 38 of a plate 34 may be sized differently from one another.
[0039] Figure 5 illustrates another example plate 134 including openings 138A and 138B. in the example shown, the opening 138B is a central circular through hole, with C-shaped through openings 138A positioned radially outward of the opening 138B. Applicant has found that the size and shape of openings may be varied to attenuate certain acoustic frequencies.
[0040] As illustrated in Figure 6, the resonator 26 is received at the discharge opening 24. In some examples, as shown, the outer pipe 28 may include a radially inwardlyextending shelf 42 attached near the discharge opening 24. In some examples, the shelf 42 is attached to the housing 22. A series of stacked plates 34A-34I are received against the shelf 42 within the outer pipe. More or fewer plates 34 may be utilized in some examples. A retainer 44 may be received against the most downstream plate 34I and may include an opening 46 for refrigerant flow. In some examples, as shown, the diameter of the opening 46 increases as the opening 46 extends away from the plates 34. The plates 34 abut their respective adjacent plate or plates 34.
[0041] Figure 7 schematically illustrates the flow of refrigerant through the example resonator 26. As shown, the openings 38 of adjacent plates 34 may be aligned and may vary in diameter and / or cross-sectional area. For example, as shown, the diameter, and thus cross-sectional area, of the opening 38B of plate 34B may be larger than the openings 38A, 38C of the plates 34A, 34C so as to create a quarter wave tube section 46 for noise attenuation. Additional plates 34, such as plates 34D, 34F, and 34H may have larger diameter openings 38 than their respective adjacent plates so as to create additional quarter wave tube regions 46 in some examples. The centers of openings 38 from adjacent plates may be aligned in some examples. The respective axial thicknesses of the plates 34 may be varied. In some examples, a plate with a larger opening 38 than those of the adjacent plates may also have a larger thickness than the thickness of one or both of its adjacent plates. The flow splitter 40 directs the refrigerant into the openings 38.
[0042] Figure 8 illustrates the negative or fluid domain of the example resonator 26.
[0043] Figure 9 illustrates an example alignment of adjacent plates 34A, 34B (not shown, see Figure 7). In Figure 9, plate 34B is behind plate 34A, and the openings 38B of plate 34B are shown as dashed lines. One or more openings 38A of the plate 34A (see Figure 7) overlap with one or more of the openings 38B of the adjacent plate 34B to allow refrigerant to flow through consecutive openings 38A, 38B. In some examples, as shown, the openings 38A, 38B are circular through holes, and the openings 38A, 38B are concentric on the same center axis C. In the example shown, the openings 38B are larger than their adjacent openings 38A. Openings 38C of the next adjacent plate 34C (not shown, see Figure 7) may be aligned in similar fashion and may be smaller than the openings 38B. Further downstream openings 38may also be concentric about the axis C. A skilled person having the benefit of this disclosure would recognize that other alignments of the openings 38 may be utilized.
[0044] Figure 10 illustrates an example noise attenuation simulation result of an example resonator 26. This plot shows the performance of the resonator transmission loss at each frequency from 0 – 15,000 Hz. This plot shows that frequencies from 4900 Hz to 10000 Hz will experience at least a 11 dB reduction in acoustic noise
[0045] The examples disclosed herein decrease the acoustic level of the discharge flow of a given centrifugal, refrigerant compressor system by attenuating specific acoustics frequencies in the discharging refrigerant through the usage of quarter wave tubes in a resonator.
[0046] The example resonators can be implemented at the discharge pipe of a centrifugal compressor. At this location, the pressurized refrigerant flow leaving the compressor will be directed into the configurable resonator.
[0047] The configurable resonators may be composed of a series of plates with different sized openings machined into them. These plates can have different dimensions and opening configurations. The opening configuration and dimensions of the plate can be changed to accommodate different refrigerants and volumetric flows. When several plates with different sized openings are stacked in series inside of a pipe with a retaining piece, they can create a resonator with quarter wave tubes. When the plates are lined up in series, the different sized openings create quarter wave tubes that work to attenuate certain acoustic frequencies present in the discharge flow of a refrigerant, compressor. The dimensions of the plates are configurable for use with different refrigerants and volumetric flows. The number of plates is configurable to cover smaller or larger frequency bands.
[0048] The lengths of these quarter wave tubes, or size of the openings in each plate, may be determined by the wavelengths of the desired frequencies to be attenuated in the discharge flow of the compressor. The number of plates in the resonator can be configured to cover a larger or smaller frequency band.
[0049] An example refrigerant compressor may be said to include a volute, and a resonator positioned near a discharge opening of the volute. The example resonator may include a pipe including an inlet, and a plurality of plates positioned near the inlet. A first ofthe plurality of plates may include a first opening, and a second of the plurality of plates may include a second opening sized differently from the first opening.
[0050] Although the different examples are illustrated as having specific components, the examples of this disclosure are not limited to those particular combinations. It is possible to use some of the components or features from any of the embodiments in combination with features or components from any of the other embodiments.
[0051] The foregoing description shall be interpreted as illustrative and not in any limiting sense. A worker of ordinary skill in the art would understand that certain modifications could come within the scope of this disclosure. For these reasons, the following claims should be studied to determine the true scope and content of this disclosure
Claims
CLAIMS What is claimed is:
1. A refrigerant compressor, comprising: a volute; and a resonator positioned near a discharge opening of the volute, the resonator including: a pipe including an inlet; and a plurality of plates positioned near the inlet, wherein a first one of the plurality of plates includes a first opening, and a second one of the plurality of plates includes a second opening sized differently from the first opening.
2. The refrigerant compressor of claim 1, wherein a third one of the plurality of plates includes a third opening.
3. The refrigerant compressor of claim 1, wherein the first one of the plurality of plates has a first thickness and the second one of the plurality of plates has a second thickness different from the first thickness.
4. The refrigerant compressor of claim 1, wherein the pipe provides a shelf, and the first one of the plurality of plates is received against the shelf.
5. The refrigerant compressor of claim 1, wherein the pipe is positioned on a center axis, and the plurality of plates are concentric with the pipe relative to the center axis.
6. The refrigerant compressor of claim 1, comprising a flow splitter disposed at the inlet.
7. The refrigerant compressor of claim 1, wherein the first opening and the second opening are circular through holes.
8. The refrigerant compressor of claim 7, wherein the pipe is positioned on a center axis, and the plurality of plates are concentric with the pipe relative to the center axis.
9. The refrigerant compressor of claim 8, wherein the first opening and the second opening are concentric about a second axis.
10. The refrigerant compressor of claim 1, comprising a retainer received against plurality of plates including a retainer opening.
11. The refrigerant compressor of claim 10, wherein a diameter of the retainer opening increases as the retainer opening extends away from the plurality of plates.
12. The refrigerant compressor of claim 1, wherein the first opening is one of a first group of four openings in the first one of the plurality of plates, and the second opening is one of a second group of four openings in the second one of the plurality of plates.
13. The refrigerant compressor of claim 1, wherein the first opening is one of a first group of four openings in the first one of the plurality of plates, and the second opening is one of a second group of four openings in the second one of the plurality of plates.
14. The refrigerant compressor of claim 13, wherein each of the first group of four openings at least partially overlaps with a respective one of the second group of four openings.
15. The refrigerant compressor of claim 14, wherein the first one of the plurality of plates has a first thickness and the second one of the plurality of plates has a second thickness different from the first thickness.
16. The refrigerant compressor of claim 15, wherein the first one of the plurality of plates is received against the second one of the plurality of plates.
17. The refrigerant compressor of claim 1, wherein a third one of the plurality of plates includes a third opening and is downstream of the first and second ones of the plurality of plates, the third opening having a greater cross-sectional area than each of the first and second openings.
18. The refrigerant compressor of claim 17, wherein the first, second, and third openings are each circular through holes concentric about an axis.
19. The refrigerant compressor of claim 18, wherein the third one of the plurality of plates has a different thickness from at least one of the first and second ones of the plurality of plates.
20. The refrigerant compressor of claim 19, wherein the pipe provides a shelf, and the first one of the plurality of plates is received against the shelf.