Heatsink for refrigerant compressor electronic component cooling

Abstract

An electric compressor includes an electric motor driving a rotor. The electric motor includes a motor rotor and stator. A current supply supplies current to the motor stator. Electronics are associated with the electric motor. The electronics are mounted on a heatsink, and the heatsink receives a connection to supply a cooling refrigerant to cool the electronic components on the heatsink. There is a cooling fluid circuit within the heatsink, with the cooling fluid circuit including at least one curved bend and a cooling channel path separated into a plurality of smaller channels. A refrigerant system is also disclosed.

Description

HEATSINK FOR REFRIGERANT COMPRESSOR ELECTRONIC COMPONENTCOOLINGRELATED APPLICATION(S)

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 522,233 filed June 21, 2023, the entirety of which is herein incorporated by reference.BACKGROUND

[0002] This application relates to a heatsink for cooling electronic components that control the supply of current to a refrigerant compressor.

[0001] Refrigerant compressors are known, and typically include an electric motor driving a compressor rotor. Current must be supplied to the electric motor, and there are typically power controls associated with the supply of the current to the electric motor.

[0002] One example power control is an insulated-gated bipolar transistor (“IGBT”). Another component which is often utilized is a silicon controlled rectifier (“SCR”).

[0003] These components and other electronic components associated with the electric motor generate a high amount of heat. Thus, it is known to provide a heatsink for the component and route cool refrigerant through the heatsink to cool the components. The cooled refrigerant is tapped from a location where the refrigerant would be sufficiently cool, such as adjacent the evaporator in a refrigerant circuit, intermediate an expansion device and the evaporator.

[0004] Known heatsink cooling circuits have an undue pressure drop, which impacts the efficiency of the overall refrigerant system.SUMMARY

[0005] In a featured embodiment, an electric compressor includes an electric motor driving a rotor. The electric motor includes a motor rotor and stator. A current supply supplies current to the motor stator. Electronics are associated with the electric motor. The electronics are mounted on a heatsink, and the heatsink receives a connection to supply a cooling refrigerant to cool the electronic components on the heatsink. There is a cooling fluid circuitwithin the heatsink, with the cooling fluid circuit including at least one curved bend and a cooling channel path separated into a plurality of smaller channels.

[0006] In another embodiment according to the previous embodiment, the electronic component includes an insulated-gated bipolar transistor.

[0007] In another embodiment according to any of the previous embodiments, the electronic component includes a silicon controlled rectifier.

[0008] In another embodiment according to any of the previous embodiments, upstream flow dividers are positioned in the cooling fluid circuit upstream of the at least one curved bend.

[0009] In another embodiment according to any of the previous embodiments, downstream flow dividers are positioned downstream of the at least one curved bend.

[0010] In another embodiment according to any of the previous embodiments, downstream flow dividers are positioned downstream of the at least one curved bend.

[0011] In another embodiment according to any of the previous embodiments, a central flow separator continues through a u-curved area downstream of the at least one curved bend.

[0012] In another embodiment according to any of the previous embodiments, an inlet to the cooling fluid circuit moves into an area that expands a cross-sectional area before the at least one curved bend.

[0013] In another embodiment according to any of the previous embodiments, the cooling fluid circuit continues to be in lodged in a cross-sectional area downstream of the at least one bend.

[0014] In another embodiment according to any of the previous embodiments, there are further u-shaped curved areas upstream u-shaped curved area.

[0015] In another featured embodiment, a refrigerant system includes a main refrigerant loop including a condenser, an evaporator and an expansion device. An electric compressor delivers refrigerant into the condenser. Refrigerant downstream of the condenser passes through the expansion device. The refrigerant downstream of the expansion device passes through an evaporator to cool a secondary fluid. The electric compressor has an electric motor. An electric motor drives a rotor. The electric motor includes a motor rotor and stator. A current supply supplies current to the motor stator. Electronics are associated with theelectric motor. The electronics are mounted on a heatsink, and the heatsink receiving a connection to supply a cooling refrigerant to cool the electronic components on the heatsink. There is a cooling fluid circuit within the heatsink, with the cooling fluid circuit including at least one curved bend and a cooling channel path separated into a plurality of smaller channels. An inlet to the cooling fluid circuit taps a cooled refrigerant from a location intermediate the expansion device and the evaporator.

[0016] In another embodiment according to any of the previous embodiments, the electronic component includes an insulated-gated bipolar transistor.

[0017] In another embodiment according to any of the previous embodiments, the electronic component includes a silicon controlled rectifier.

[0018] In another embodiment according to any of the previous embodiments, upstream flow dividers are positioned in the cooling fluid circuit upstream of the at least one curved bend.

[0019] In another embodiment according to any of the previous embodiments, downstream flow dividers are positioned downstream of the at least one curved bend.

[0020] In another embodiment according to any of the previous embodiments, downstream flow dividers are positioned downstream of the at least one curved bend.

[0021] In another embodiment according to any of the previous embodiments, a central flow separator continues through a u-curved area downstream of the at least one curved bend.

[0022] In another embodiment according to any of the previous embodiments, an inlet to the cooling fluid circuit moves into an area that expands a cross-sectional area before the at least one curved bend.

[0023] In another embodiment according to any of the previous embodiments, the cooling fluid circuit continues to be in lodged in a cross-sectional area downstream of the at least one bend.

[0024] In another embodiment according to any of the previous embodiments, there are further u-shaped curved areas upstream u-shaped curved area.

[0025] These and other features will be best understood from the following drawings and specification, the following is a brief description.BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 schematically shows a refrigerant circuit.

[0027] Figure 2 schematically shows a refrigerant compressor.

[0028] Figure 3A shows a heatsink for the Figure 2 refrigerant compressor.

[0029] Figure 3B shows a first cooling circuit detail.

[0030] Figure 3C shows further details.

[0031] Figure 3D is a cross-sectional view along line D-D of Figure 3C.

[0032] Figure 3E is a perspective view of a heatsink.

[0033] Figure 4 compares a pressure drop for cooling fluid with the disclosed cooling circuit compared to a more standard cooling circuit.DETAILED DESCRIPTION

[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, in cross-section, a portion of the compressor 14. The compressor 14 includes an electric motor 22 having a stator 24 arranged radially outside of a rotor 26. The rotor 26 is connected to a shaft 28, which rotates to drive at least one compression stage 30 of the compressor 14, which in this example includes at least one impeller 32. The compressor 14 may include multiple compression stages.

[0036] The shaft 28 and impeller 32 are rotatable by the electric motor 22 about an axis A to compress refrigerant F. The terms axial, radial, and circumferential in this disclosure are used relative to the axis A. The shaft 28 may be rotatably supported by a plurality of bearing assemblies, which in one example are magnetic bearing assemblies.

[0037] During operation of the compressor 14, refrigerant F flows axially toward the impeller 32 and is expelled radially outwardly to a diffuser 34 downstream of the impeller 32. The diffuser 34 is arranged radially between the outlet of the impeller 32 and a volute 40. The volute 40 may be in fluid communication with the condenser 16 or another compression stage of the compressor 14.

[0038] Returning to Figure 1, a cooling fluid is tapped from the circuit 12 after it has been expanded by the expansion device 20, and before it is heated across the evaporator 18. That cooling fluid passes to a heatsink 50 on an outer wall of compressor 14.

[0039] Figure 2 shows the heatsink 50 receiving the cooling fluid 52, schematically.

[0040] A power line 54 passes from components on the heatsink 50 to the stator 24. Heatsink 50 provides the function of cooling electronic components, such as power controls associated with the supply of current to power line 54.

[0041] Figure 3A shows a heatsink 50 supporting an insulated-gated bipolar transistor (“IGBT”) 56. Further, a silicon controlled rectifier (“SCR”) 58 is shown.

[0042] Figure 3B shows a cooling circuit 60 within a body of the heatsink 50 and passing beneath the IGBT 56 and the SCR 58. As shown, inlet 62 has a relatively small cross- sectional area, and expands through a portion 64 to an enlarged cross-sectional area 64. The enlarged cross-sectional area 64 reaches a bend 66 where it turns through approximately 90 degrees, and continues to be enlarged. Another area 68 includes a number of flow dividers (described below). Eventually the cooling fluid goes through several other bends and then reaches an outlet 70.

[0043] Figure 3B is somewhat schematic.

[0044] Figure 3C shows more detailed structure of the cooling circuit 60. Again, inlet 62 leads into an enlarged portion 64. Enlarged portion 64 passes to a bend or turning area 66. Turning area 66 leads into a minichannel area 68 wherein the flow is divided into a plurality of flow passages 78. Eventually the flow reaches an outlet 70.

[0045] As shown, a flow divider 72 is positioned upstream of the bend 66 and separates the flow into two channels 74. Then, there are two additional separators 76 placed within each channel 74 to further separate the flow into three separate channels 78.

[0046] A central downstream separator 72 continues further through a u-shaped curved area 90 and a further u-shaped area 92. The separators 76 have end at a space 80, andthen the channels are again separated by end separators 82 into a plurality of channels 86, before reaching outlet 70.

[0047] Figure 3D is a cross-sectional view along D-D of Figure 3C. One can see the flow channels within the body of the heatsink 50.

[0048] The electronic components disclosed to this point have been discussed somewhat schematically. An actual heatsink 50 is illustrated in Figure 3E and shows a plurality of electronic components 80 are mounted on the heatsink 50. IGBT 56 and SCR 58 are shown. The inlet 62 is shown along with the outlet 70.

[0049] Figure 4 is a graph showing the pressure drop with standard cooling surface without the minichannel design at X. As one can see with increased mass flow rate the pressure drop increases dramatically. The disclosed minichannel flow circuit is shown at Y. As one can see the pressure drop is very low compared to pressure drop X and is also relatively constant.

[0050] Although an embodiment has been disclosed, a worker of skill in this art would recognize that modifications would come within the scope of this disclosure. For that reason, the following claims should be studied to determine the true scope and content of this disclosure.

Claims

CLAIMSWhat is claimed is:

1. An electric compressor comprising: an electric motor driving a rotor; the electric motor including a motor rotor and stator; a current supply for supplying current to the motor stator; electronics associated with the electric motor; the electronics mounted on a heatsink, and the heatsink receiving a connection to supply a cooling refrigerant to cool the electronic components on the heatsink; and there being a cooling fluid circuit within the heatsink, with the cooling fluid circuit including at least one curved bend and a cooling channel path separated into a plurality of smaller channels.

2. The electric compressor as set forth in claim 1, wherein the electronic component includes an insulated-gated bipolar transistor.

3. The electric compressor as set forth in claim 1, wherein the electronic component includes a silicon controlled rectifier.

4. The electric compressor as set forth in claim 1, wherein upstream flow dividers are positioned in the cooling fluid circuit upstream of the at least one curved bend.

5. The electric compressor as set forth in claim 4, wherein downstream flow dividers are positioned downstream of the at least one curved bend.

6. The electric compressor as set forth in claim 1, wherein downstream flow dividers are positioned downstream of the at least one curved bend.

7. The electric compressor as set forth in claim 6, wherein a central flow separator continues through a u-curved area downstream of the at least one curved bend.

8. The electric compressor as set forth in claim 7, wherein an inlet to the cooling fluid circuit moves into an area that expands a cross-sectional area before the at least one curved bend.

9. The electric compressor as set forth in claim 8, wherein the cooling fluid circuit continues to be in lodged in a cross-sectional area downstream of the at least one bend.

10. The electric compressor as set forth in claim 7, wherein there are further u-shaped curved areas upstream u-shaped curved area.

11. A refrigerant system comprising: a main refrigerant loop including a condenser, an evaporator and an expansion device, with an electric compressor delivering refrigerant into the condenser, refrigerant downstream of the condenser passing through the expansion device, and the refrigerant downstream of the expansion device passing through an evaporator to cool a secondary fluid; the electric compressor having an electric motor; an electric motor driving a rotor; the electric motor including a motor rotor and stator; a current supply for supplying current to the motor stator; electronics associated with the electric motor; the electronics mounted on a heatsink, and the heatsink receiving a connection to supply a cooling refrigerant to cool the electronic components on the heatsink; there being a cooling fluid circuit within the heatsink, with the cooling fluid circuit including at least one curved bend and a cooling channel path separated into a plurality of smaller channels; and an inlet to the cooling fluid circuit taps a cooled refrigerant from a location intermediate the expansion device and the evaporator.

12. The refrigerant system as set forth in claim 11, wherein the electronic component includes an insulated-gated bipolar transistor.

13. The refrigerant system as set forth in claim 11, wherein the electronic component includes a silicon controlled rectifier.

14. The refrigerant system as set forth in claim 11, wherein upstream flow dividers are positioned in the cooling fluid circuit upstream of the at least one curved bend.

15. The refrigerant system as set forth in claim 14, wherein downstream flow dividers are positioned downstream of the at least one curved bend.

16. The refrigerant system as set forth in claim 11, wherein downstream flow dividers are positioned downstream of the at least one curved bend.

17. The refrigerant system as set forth in claim 16, wherein a central flow separator continues through a u-curved area downstream of the at least one curved bend.

18. The refrigerant system as set forth in claim 17, wherein an inlet to the cooling fluid circuit moves into an area that expands a cross-sectional area before the at least one curved bend.

19. The refrigerant system as set forth in claim 18, wherein the cooling fluid circuit continues to be in lodged in a cross-sectional area downstream of the at least one bend.

20. The refrigerant system as set forth in claim 7, wherein there are further u-shaped curved areas upstream u-shaped curved area.

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