U.S. patent application number 17/575708 was filed with the patent office on 2022-08-04 for refrigerant compressor with impeller having dual splitter blade arrangement.
The applicant listed for this patent is DANFOSS A/S. Invention is credited to Jin Yan.
Application Number | 20220243966 17/575708 |
Document ID | / |
Family ID | 1000006152011 |
Filed Date | 2022-08-04 |
United States Patent
Application |
20220243966 |
Kind Code |
A1 |
Yan; Jin |
August 4, 2022 |
REFRIGERANT COMPRESSOR WITH IMPELLER HAVING DUAL SPLITTER BLADE
ARRANGEMENT
Abstract
In some aspects, the techniques described herein relate to a
refrigerant compressor, including an impeller including a plurality
of main blades and first and second splitter blades between
adjacent main blades.
Inventors: |
Yan; Jin; (Tallahassee,
FL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
DANFOSS A/S |
NORDBORG |
|
DK |
|
|
Family ID: |
1000006152011 |
Appl. No.: |
17/575708 |
Filed: |
January 14, 2022 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
63145512 |
Feb 4, 2021 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F04D 29/284 20130101;
F25B 31/026 20130101; F04D 17/10 20130101 |
International
Class: |
F25B 31/02 20060101
F25B031/02; F04D 17/10 20060101 F04D017/10; F04D 29/28 20060101
F04D029/28 |
Claims
1. A refrigerant compressor, comprising: an impeller including a
plurality of main blades and first and second splitter blades
between adjacent main blades.
2. The refrigerant compressor as recited in claim 1, wherein the
first splitter blade is spaced-apart circumferentially from the
second splitter blade.
3. The refrigerant compressor as recited in claim 1, wherein: the
first splitter blade extends a first length between a leading edge
and a trailing edge thereof, the second splitter blade extends a
second length between a leading edge and a trailing edge thereof,
and the first length is greater than the second length.
4. The refrigerant compressor as recited in claim 3, wherein: each
main blade extends a third length between a leading edge and a
trailing edge thereof, and the third length is greater than the
first and second lengths.
5. The refrigerant compressor as recited in claim 4, wherein the
leading edges of the first splitter blade, the second splitter
blade, and each main blade are staggered relative to one
another.
6. The refrigerant compressor as recited in claim 5, wherein the
trailing edges of the first splitter blade, the second splitter
blade, and each main blade are aligned relative to one another.
7. The refrigerant compressor as recited in claim 6, wherein the
trailing edges of the first splitter blade, the second splitter
blade, and each main blade are provided at a common radial distance
from a rotational axis of the impeller and are coextensive with an
exit of the impeller.
8. The refrigerant compressor as recited in claim 6, wherein: the
leading edge of the first splitter blade is spaced-apart from the
leading edge of each main blade by a distance within a range of
30-60% of the third length, and the leading edge of the second
splitter blade is spaced-apart from the leading of the first
splitter blade by a distance within a range of 30-60% of the first
length.
9. The refrigerant compressor as recited in claim 6, wherein: the
first splitter blade exhibits a first maximum thickness, the second
splitter blade exhibits a second maximum thickness less than the
first maximum thickness, and each main blade exhibits a third
maximum thickness greater than the first and second maximum
thicknesses.
10. The refrigerant compressor as recited in claim 6, wherein: the
leading edges of each main blade, the first splitter blade, and the
second splitter blade are swept so as to be inclined toward
respective trailing edges.
11. The refrigerant compressor as recited in claim 1, wherein
camber lines of each main blade, the first splitter blade, and the
second splitter blade are parallel to one another.
12. The refrigerant compressor as recited in claim 1, wherein the
impeller includes seven main blades and 14 splitter blades.
13. The refrigerant compressor as recited in claim 1, wherein the
impeller is not shrouded.
14. A refrigerant compressor, comprising: an impeller including a
plurality of main blades and first and second splitter blades
between adjacent main blades, wherein the first splitter blade is
spaced-apart circumferentially from the second splitter blade,
wherein the first splitter blade extends a first length between a
leading edge and a trailing edge thereof, wherein the second
splitter blade extends a second length between a leading edge and a
trailing edge thereof, wherein the first length is greater than the
second length, wherein each main blade extends a third length
between a leading edge and a trailing edge thereof, wherein the
third length is greater than the first and second lengths, wherein
the leading edges of the first splitter blade, the second splitter
blade, and each main blade are staggered relative to one another,
wherein the trailing edges of the first splitter blade, the second
splitter blade, and each main blade are aligned relative to one
another, wherein the trailing edges of the first splitter blade,
the second splitter blade, and each main blade are provided at a
common radial distance from a rotational axis of the impeller and
are coextensive with an exit of the impeller, wherein the leading
edge of the first splitter blade is spaced-apart from the leading
edge of each main blade by a distance within a range of 30-60% of
the third length, wherein the leading edge of the second splitter
blade is spaced-apart from the leading of the first splitter blade
by a distance within a range of 30-60% of the first length, wherein
the first splitter blade exhibits a first maximum thickness,
wherein the second splitter blade exhibits a second maximum
thickness less than the first maximum thickness, wherein each main
blade exhibits a third maximum thickness greater than the first and
second maximum thicknesses, wherein the leading edges of each main
blade, the first splitter blade, and the second splitter blade are
swept so as to be inclined toward respective trailing edges, and
wherein camber lines of each main blade, the first splitter blade,
and the second splitter blade are parallel to one another.
15. The refrigerant compressor as recited in claim 14, wherein: the
impeller includes seven main blades and 14 splitter blades, and the
impeller is not shrouded.
16. A refrigerant system, comprising: a main refrigerant loop
including a compressor, a condenser, an evaporator, and an
expansion device, wherein the compressor includes an impeller
including a plurality of main blades and first and second splitter
blades between adjacent main blades.
17. The refrigerant system as recited in claim 16, wherein: the
first splitter blade extends a first length between a leading edge
and a trailing edge thereof, the second splitter blade extends a
second length between a leading edge and a trailing edge thereof,
the first length is greater than the second length, each main blade
extends a third length between a leading edge and a trailing edge
thereof, and the third length is greater than the first and second
lengths.
18. The refrigerant system as recited in claim 17, wherein: the
leading edges of the first splitter blade, the second splitter
blade, and each main blade are staggered relative to one another,
and the trailing edges of the first splitter blade, the second
splitter blade, and each main blade are aligned relative to one
another.
19. The refrigerant system as recited in claim 17, wherein: the
leading edge of the first splitter blade is spaced-apart from the
leading edge of each main blade by a distance within a range of
30-60% of the third length, and the leading edge of the second
splitter blade is spaced-apart from the leading of the first
splitter blade by a distance within a range of 30-60% of the first
length.
20. The refrigerant system as recited in claim 17, wherein: the
first splitter blade exhibits a first maximum thickness, the second
splitter blade exhibits a second maximum thickness less than the
first maximum thickness, and each main blade exhibits a third
maximum thickness greater than the first and second maximum
thicknesses.
Description
RELATED APPLICATION(S)
[0001] This application claims the benefit of U.S. Provisional
Application No. 63/145,512, filed Feb. 4, 2021, the entirety of
which is herein incorporated by reference.
BACKGROUND
[0002] Refrigerant compressors are used to circulate refrigerant in
a chiller via a refrigerant loop. Refrigerant loops are known to
include a compressor, a condenser, an expansion device, and an
evaporator. The compressor compresses the fluid, which then travels
to the condenser, which in turn cools and condenses the fluid. The
refrigerant then goes to the 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.
SUMMARY
[0004] In some aspects, the techniques described herein relate to a
refrigerant compressor, including: an impeller including a
plurality of main blades and first and second splitter blades
between adjacent main blades.
[0005] In some aspects, the techniques described herein relate to a
refrigerant compressor, wherein the first splitter blade is
spaced-apart circumferentially from the second splitter blade.
[0006] In some aspects, the techniques described herein relate to a
refrigerant compressor, wherein: the first splitter blade extends a
first length between a leading edge and a trailing edge thereof,
the second splitter blade extends a second length between a leading
edge and a trailing edge thereof, and the first length is greater
than the second length.
[0007] In some aspects, the techniques described herein relate to a
refrigerant compressor, wherein: each main blade extends a third
length between a leading edge and a trailing edge thereof, and the
third length is greater than the first and second lengths.
[0008] In some aspects, the techniques described herein relate to a
refrigerant compressor, wherein the leading edges of the first
splitter blade, the second splitter blade, and each main blade are
staggered relative to one another.
[0009] In some aspects, the techniques described herein relate to a
refrigerant compressor, wherein the trailing edges of the first
splitter blade, the second splitter blade, and each main blade are
aligned relative to one another.
[0010] In some aspects, the techniques described herein relate to a
refrigerant compressor, wherein the trailing edges of the first
splitter blade, the second splitter blade, and each main blade are
provided at a common radial distance from a rotational axis of the
impeller and are coextensive with an exit of the impeller.
[0011] In some aspects, the techniques described herein relate to a
refrigerant compressor, wherein: the leading edge of the first
splitter blade is spaced-apart from the leading edge of each main
blade by a distance within a range of 30-60% of the third length,
and the leading edge of the second splitter blade is spaced-apart
from the leading of the first splitter blade by a distance within a
range of 30-60% of the first length.
[0012] In some aspects, the techniques described herein relate to a
refrigerant compressor, wherein: the first splitter blade exhibits
a first maximum thickness, the second splitter blade exhibits a
second maximum thickness less than the first maximum thickness, and
each main blade exhibits a third maximum thickness greater than the
first and second maximum thicknesses.
[0013] In some aspects, the techniques described herein relate to a
refrigerant compressor, wherein: the leading edges of each main
blade, the first splitter blade, and the second splitter blade are
swept so as to be inclined toward respective trailing edges.
[0014] In some aspects, the techniques described herein relate to a
refrigerant compressor, wherein camber lines of each main blade,
the first splitter blade, and the second splitter blade are
parallel to one another.
[0015] In some aspects, the techniques described herein relate to a
refrigerant compressor, wherein the impeller includes seven main
blades and 14 splitter blades.
[0016] In some aspects, the techniques described herein relate to a
refrigerant compressor, wherein the impeller is not shrouded.
[0017] In some aspects, the techniques described herein relate to a
refrigerant compressor, including: an impeller including a
plurality of main blades and first and second splitter blades
between adjacent main blades, wherein the first splitter blade is
spaced-apart circumferentially from the second splitter blade,
wherein the first splitter blade extends a first length between a
leading edge and a trailing edge thereof, wherein the second
splitter blade extends a second length between a leading edge and a
trailing edge thereof, wherein the first length is greater than the
second length, wherein each main blade extends a third length
between a leading edge and a trailing edge thereof, wherein the
third length is greater than the first and second lengths, wherein
the leading edges of the first splitter blade, the second splitter
blade, and each main blade are staggered relative to one another,
wherein the trailing edges of the first splitter blade, the second
splitter blade, and each main blade are aligned relative to one
another, wherein the trailing edges of the first splitter blade,
the second splitter blade, and each main blade are provided at a
common radial distance from a rotational axis of the impeller and
are coextensive with an exit of the impeller, wherein the leading
edge of the first splitter blade is spaced-apart from the leading
edge of each main blade by a distance within a range of 30-60% of
the third length, wherein the leading edge of the second splitter
blade is spaced-apart from the leading of the first splitter blade
by a distance within a range of 30-60% of the first length, wherein
the first splitter blade exhibits a first maximum thickness,
wherein the second splitter blade exhibits a second maximum
thickness less than the first maximum thickness, wherein each main
blade exhibits a third maximum thickness greater than the first and
second maximum thicknesses, wherein the leading edges of each main
blade, the first splitter blade, and the second splitter blade are
swept so as to be inclined toward respective trailing edges, and
wherein camber lines of each main blade, the first splitter blade,
and the second splitter blade are parallel to one another.
[0018] In some aspects, the techniques described herein relate to a
refrigerant compressor, wherein: the impeller includes seven main
blades and 14 splitter blades, and the impeller is not
shrouded.
[0019] In some aspects, the techniques described herein relate to a
refrigerant system, including: a main refrigerant loop including a
compressor, a condenser, an evaporator, and an expansion device,
wherein the compressor includes an impeller including a plurality
of main blades and first and second splitter blades between
adjacent main blades.
[0020] In some aspects, the techniques described herein relate to a
refrigerant system, wherein: the first splitter blade extends a
first length between a leading edge and a trailing edge thereof,
the second splitter blade extends a second length between a leading
edge and a trailing edge thereof, the first length is greater than
the second length, each main blade extends a third length between a
leading edge and a trailing edge thereof, and the third length is
greater than the first and second lengths.
[0021] In some aspects, the techniques described herein relate to a
refrigerant system, wherein: the leading edges of the first
splitter blade, the second splitter blade, and each main blade are
staggered relative to one another, and the trailing edges of the
first splitter blade, the second splitter blade, and each main
blade are aligned relative to one another.
[0022] In some aspects, the techniques described herein relate to a
refrigerant system, wherein: the leading edge of the first splitter
blade is spaced-apart from the leading edge of each main blade by a
distance within a range of 30-60% of the third length, and the
leading edge of the second splitter blade is spaced-apart from the
leading of the first splitter blade by a distance within a range of
30-60% of the first length.
[0023] In some aspects, the techniques described herein relate to a
refrigerant system, wherein: the first splitter blade exhibits a
first maximum thickness, the second splitter blade exhibits a
second maximum thickness less than the first maximum thickness, and
each main blade exhibits a third maximum thickness greater than the
first and second maximum thicknesses.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] FIG. 1 schematically illustrates a refrigerant system.
[0025] FIG. 2 is a schematic, partial cross-sectional view of a
compressor.
[0026] FIG. 3 is an axial end view of an example impeller.
[0027] FIG. 4 is a cross-sectional illustration of a portion of the
impeller, and in particular illustrates an exemplary blade
arrangement, including a main blade, a first splitter blade, and a
second splitter blade.
[0028] FIG. 5 is a blade-to-blade view of the blade
arrangement.
DETAILED DESCRIPTION
[0029] FIG. 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.
[0030] FIG. 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.
[0031] 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.
[0032] 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.
[0033] FIG. 3 is an axial end view of the impeller 32 along the
axis A. The impeller 32 is configured to rotate in a
counter-clockwise direction, in this example. The impeller 32 is
not shrouded in this example. However, the impeller 32 could be
shrouded.
[0034] The impeller 32 includes a plurality of blades projecting
radially outward from a hub 42. In particular, the impeller 32
includes a plurality of main blades 44 spaced-apart from one
another circumferentially about the axis A. Two of the main blades
44 are labeled in FIG. 3. The impeller 32 includes seven total main
blades 44 in the example of FIG. 3. This disclosure extends to
impellers that include another number of main blades 44.
[0035] With reference to FIGS. 4 and 5, the main blades 44 extend
from a leading edge 46 adjacent an inlet to the impeller 32 to a
trailing edge 48 adjacent an outlet of the impeller 32. The main
blades 44 are configured to receive a flow of fluid flowing in an
axial direction and to turn that flow such that it is radially
expelled from the impeller 32.
[0036] Between each of the adjacent main blades 44, the impeller 32
includes first and second splitter blades 50, 52, in this example.
The arrangement of a main blade 44, a first splitter blade 50, and
a second splitter blade 52 is continued and repeated about the axis
A.
[0037] The first splitter blade 50 extends between a leading edge
54 and a trailing edge 56. Likewise, the second splitter blade 52
extends between a leading edge 58 and a trailing edge 60.
[0038] The first and second splitter blades 50, 52 are shorter than
the main blades 44. Specifically, a length of the first and second
splitter blades 50, 52 between the respective leading and trailing
edges is less than that of the main blades 44. Further, the second
splitter blades 52 are shorter than the first splitter blades
50.
[0039] The main blades 44 and first and second splitter blades 50,
52 are staggered relative to one another along the impeller 32. In
particular, with reference to FIG. 5, the leading edges 46, 54, 58
are spaced-apart from one another while the trailing edges 48, 56,
60 are aligned. In particular, the trailing edges 48, 56, 60 are
provided at a common distance, namely a radial distance, away from
the axis A. The trailing edges 48, 56, 60 are coextensive with the
exit of the impeller 32, in this example.
[0040] Referring to FIG. 5, in this example, the leading edge 54 is
spaced-apart from the leading edge 48 by a distance D.sub.1 within
a range of 30-60% of the overall length of the main blade 44. The
leading edge 58 is spaced-apart from the leading edge 54 by a
distance D.sub.2 within a range of 30-60% of the overall length of
the splitter blade 50. The lengths of the blades 44, 50, 52 are
measured along their camber lines, in this example. The distances
D.sub.1, D.sub.2 are measured parallel to the camber lines.
[0041] The first and second splitter blades 50, 52 extend parallel
to the main blade 44, meaning their respective camber lines are
parallel to one another. Further, the first splitter blade 50
exhibits a maximum thickness T.sub.2 less than a maximum thickness
T.sub.1 of the main blade 44. The thicknesses T.sub.1, T.sub.2 are
greater than the maximum thickness T.sub.3 of the second splitter
blade 52. Further, the leading edges 46, 54, 58 may be swept, and
specifically inclined toward the trailing edges 48, 56, 60 in some
examples.
[0042] The blade arrangement of this disclosure provides the
impeller 32 with a balance between increasing the capacity of the
compressor 14, by providing a relatively large throat between the
adjacent main blades, while still also providing a relatively high
pressure ratio, by providing two splitter blades between each main
blade. This disclosure is particularly beneficial in the context of
refrigerant compressors, and specifically those that use magnetic
bearings.
[0043] It should be understood that terms such as "axial" and
"radial" are used above with reference to the normal operational
attitude of a compressor. Further, these terms have been used
herein for purposes of explanation, and should not be considered
otherwise limiting. Terms such "generally," "about," and
"substantially" are not intended to be boundaryless terms, and
should be interpreted consistent with the way one skilled in the
art would interpret those terms.
[0044] Although the different examples have the specific components
shown in the illustrations, embodiments of this disclosure are not
limited to those particular combinations. It is possible to use
some of the components or features from one of the examples in
combination with features or components from another one of the
examples.
[0045] One of ordinary skill in this art would understand that the
above-described embodiments are exemplary and non-limiting. That
is, modifications of this disclosure would come within the scope of
the claims. Accordingly, the following claims should be studied to
determine their true scope and content.
* * * * *