U.S. patent application number 11/236763 was filed with the patent office on 2006-04-06 for compressor intended to compress coolant fluid for a refrigeration or air conditioning installation.
This patent application is currently assigned to DANFOSS COMMERCIAL COMPRESSORS. Invention is credited to Jean De Bernardi, Yves Rosson.
Application Number | 20060070398 11/236763 |
Document ID | / |
Family ID | 34951136 |
Filed Date | 2006-04-06 |
United States Patent
Application |
20060070398 |
Kind Code |
A1 |
De Bernardi; Jean ; et
al. |
April 6, 2006 |
Compressor intended to compress coolant fluid for a refrigeration
or air conditioning installation
Abstract
A compressor intended to compress coolant fluid for a
refrigeration or air conditioning installation, comprising a
substantially vertical body consisting of a casing intended to
receive in particular a lubricating liquid in its bottom portion
forming a reservoir, and means of heating the lubricating liquid.
The means of heating the lubricating liquid and means of acoustic
insulation and thermal insulation situated below the heating means
are placed close to the bottom wall of the casing.
Inventors: |
De Bernardi; Jean; (Lyon,
FR) ; Rosson; Yves; (Villars Les Dombes, FR) |
Correspondence
Address: |
OLIFF & BERRIDGE, PLC
P.O. BOX 19928
ALEXANDRIA
VA
22320
US
|
Assignee: |
DANFOSS COMMERCIAL
COMPRESSORS
Reyrieux
FR
|
Family ID: |
34951136 |
Appl. No.: |
11/236763 |
Filed: |
September 28, 2005 |
Current U.S.
Class: |
62/468 ;
417/228 |
Current CPC
Class: |
F04B 39/0207
20130101 |
Class at
Publication: |
062/468 ;
417/228 |
International
Class: |
F04B 39/06 20060101
F04B039/06; F25B 43/02 20060101 F25B043/02 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 5, 2004 |
FR |
04.10487 |
Claims
1. A compressor for compressing coolant fluid for an air
conditioning installation, comprising a substantially vertical body
comprising a casing for receiving a lubricating liquid in its
bottom portion forming a reservoir, and means of heating the
lubricating liquid, wherein the means of heating the lubricating
liquid and means of acoustic insulation and thermal insulation
situated below the heating means are placed close to the bottom
wall of the casing.
2. The compressor as claimed in claim 1, wherein the acoustic
insulation and thermal insulation means are at a distance from the
support to which the compressor is attached.
3. The compressor as claimed in claim 1, wherein the acoustic
insulation and thermal insulation means comprise at least one layer
of insulating material.
4. The compressor as claimed in claim 3, wherein at least one layer
of insulating material comprises a cellular material.
5. The compressor as claimed in claim 3, wherein at least one layer
of insulating material comprises felt.
6. The compressor as claimed in claim 3, wherein at least one layer
of insulating material comprises a fibrous material.
7. The compressor as claimed in claim 3, wherein the acoustic
insulation and thermal insulation means also comprise a rigid
support plate.
8. The compressor as claimed in claim 3, wherein the acoustic
insulation and thermal insulation means also comprise a film for
protecting and retaining the insulating material.
9. The compressor as claimed in claim 1, wherein the thermal and
acoustic insulation means have a top surface whose shape at least
in part substantially complements that of the bottom wall of the
casing.
10. The compressor as claimed in claim 1, wherein the heating means
comprise at least one electric resistance attached to the bottom
wall of the casing, outside the latter.
11. The compressor as claimed in claim 10, wherein at least one
electric resistance is attached to the bottom wall of the casing by
adhesive means.
12. The compressor as claimed in claim 1, wherein the thermal
insulation and acoustic insulation means are kept in position
relative to the body of the compressor by attachment means.
13. The compressor as claimed in claim 12, wherein the attachment
means comprise at least one elastic clip kept in position by
clipping a protruding portion of the compressor and a substantially
horizontal lug, the thermal and acoustic insulation means pressing
on the lugs of the attachment means.
14. The compressor as claimed in claim 13, wherein the attachment
means are at least two in number.
15. The compressor as claimed in claim 1, wherein the thermal and
acoustic insulation means allow the attachment feet of the
compressor to pass through.
16. The compressor as claimed in claim 1, which comprises an
acoustic insulation jacket covering the body of the compressor.
17. A thermodynamic machine including at least one compressor as
claimed in claim 1.
Description
[0001] The present invention relates to a compressor intended to
compress the coolant fluid for a refrigeration or air conditioning
installation.
BACKGROUND OF THE INVENTION
[0002] In a known manner, the phenomena of migration of the coolant
fluid within a refrigeration or air conditioning circuit appear
when the latter is not in service.
[0003] Specifically, when the compressor is at a lower temperature
than that of the heat exchangers, the coolant fluid migrates, under
the temperature gradient effect, from the heat exchangers to the
compressor.
[0004] This phenomenon occurs particularly in the morning, when the
installation is situated outdoors, the heat exchangers being heated
by the sun and rising in temperature more rapidly than the solid
parts of the compressor which have a greater thermal inertia.
[0005] This phenomenon occurs in the reverse direction after the
sun goes down, the coolant fluid migrating from the compressor to
the heat exchangers, which cool down more quickly than the
compressor.
[0006] During these migrations in the cooling circuit, the cooling
fluid, by moving in the different portions of the cooling circuit,
may cause the mechanical parts to be washed by condensation,
carrying away the fluid lubricating the walls of these parts.
[0007] Furthermore, in the casing of the compressor toward which
the coolant fluid migrates, the coolant fluid and the lubricant mix
together, these two fluids in liquid form being miscible, the
mixture having the effect of reducing the viscosity of the
lubricant.
[0008] Consequently, when the circuit is returned to service, the
lubrication is insufficient, due to the washing of the mechanical
parts and the reduction in viscosity of the lubricant, which may
cause premature wear or even a breakage of the mechanical parts of
the installation.
[0009] The known solutions for resolving this problem consist first
in having non-return valves at the outlet of the compressor, on the
discharge side, and secondly in heating the compressor casing, and
thus the lubricant contained in this casing.
[0010] This heating prevents the appearance of the temperature
gradient described hereinabove and hence the appearance of the
migration phenomenon.
[0011] The two solutions are ideally employed in parallel for
greater security.
DESCRIPTION OF THE PRIOR ART
[0012] In existing compressors, as described in document U.S. Pat.
No. 5,252,036, the heating device is situated on the side wall of
the compressor. A seal surrounds the heating device in order to
prevent an excessive heat loss toward the outside.
[0013] However, this arrangement is not very advantageous because
it cannot be used to heat all the oil by making use of the
convection currents in the casing to heat the lubricant uniformly.
On the other hand, placement on the side wall is disadvantageous
because it allows major heat loss by forced convection due to the
wind.
[0014] Document U.S. Pat. No. 4,208,883, which describes a device
for thermally regulating the temperature of the lubricant, suggests
positioning the heating device beneath the compressor. In this
document, the heating means are regulated by a device making it
possible to control the temperature of the lubricant.
[0015] However, no measure is taken to reduce the heat loss through
radiation.
[0016] In the known types of device, the criterion used to ensure
that the migration does not occur is to maintain a temperature
difference between the lubricant contained in the casing and the
outside temperature of the order of 10 K by heating.
[0017] Consequently, powers of the order of 75 to 150 W are needed
to power the heating devices. This power may have to be adjusted to
suit the size of the compressor.
[0018] In addition to the migration phenomena, a second important
technical problem relating to the compressors of the prior art
concerns their acoustic emissions.
[0019] To reduce the noise emitted by these compressors, a first
solution used in the prior art is to cover the compressor with an
absorbent jacket which can be used to achieve an attenuation of the
order of 7 dB, particularly effective for high frequencies, above
800 Hz.
[0020] However, the jackets are not effective in reducing the
emitted low frequency noise, and they also constitute devices of
complex structure combining several materials whose cost is high
compared with the cost of the compressor.
[0021] A second solution is described in document JP 53 099504, the
compressor body being mounted on springs in a compartment, this
compartment itself being mounted on springs passing through a layer
of acoustically insulating material, in the form of solid or liquid
foam situated in a housing integral with the compressor attachment
support.
[0022] This document consequently describes a complex device, in
which the compressor is completely contained in a compartment, this
disposition making access to the latter difficult and involving the
installation of an intermediate platform supporting the
compartment, which increases the overall space requirement of the
compressor.
[0023] Other documents, such as document JP 2002 243211, also
describe devices in which a compartment completely contains the
compressor, in order to reduce the emitted noise.
[0024] These devices also have disadvantages of space requirement
and complex structure and cost.
SUMMARY OF THE INVENTION
[0025] The object of the present invention is to provide a
compressor which, in a restricted space requirement and a simple
construction, can be used to achieve heating requiring a reduced
energy consumption, and to emit a reduced acoustic power,
particularly in the low frequencies.
[0026] Accordingly, the subject of the present invention is a
compressor intended to compress coolant fluid for a refrigeration
or air conditioning installation, comprising a substantially
vertical body consisting of a casing intended to receive in
particular a lubricating liquid in its bottom portion forming a
reservoir, and means of heating the lubricating liquid, wherein the
means of heating the lubricating liquid and means of acoustic
insulation and thermal insulation situated below the heating means
are placed close to the bottom wall of the casing.
[0027] Such a disposition can be used to reduce significantly the
power consumed to heat the lubricating liquid, because the heat
insulation means reflect the energy toward the compressor and the
dissipations due to the wind are diminished.
[0028] This disposition can also be used to reduce to a surprising
degree the emitted acoustic power, particularly in the field of the
low frequencies, because it appears that the low frequency waves
are emitted to a greater degree at the bottom wall of the
casing.
[0029] This disposition is also used, with the abovementioned
advantages, to cause a minimal space requirement.
[0030] Advantageously, the acoustic insulation and thermal
insulation means are at a distance from the support to which the
compressor is attached.
[0031] According to one embodiment, the acoustic insulation and
thermal insulation means comprise at least one layer of insulating
material.
[0032] Advantageously, at least one layer of insulating material
comprises a cellular material.
[0033] According to one embodiment, at least one layer of
insulating material comprises felt.
[0034] Advantageously, at least one layer of insulating material
comprises a fibrous material.
[0035] Advantageously, the acoustic insulation and thermal
insulation means also comprise a rigid support plate.
[0036] According to one embodiment, the acoustic insulation and
thermal insulation means also comprise a film for protecting and
retaining the insulating material.
[0037] Advantageously, the thermal and acoustic insulation means
have a top surface whose shape at least in part substantially
complements that of the bottom wall of the casing.
[0038] According to one embodiment, the heating means comprise at
least one electric resistance attached to the bottom wall of the
casing, outside the latter.
[0039] Advantageously, at least one electric resistance is attached
to the bottom wall of the casing by adhesive means.
[0040] According to one embodiment, the thermal insulation and
acoustic insulation means are kept in position relative to the
compressor body by attachment means.
[0041] Advantageously, the attachment means comprise at least one
elastic clip kept in position by gripping a projecting portion of
the compressor and a substantially horizontal lug, the thermal and
acoustic insulation means pressing on the lugs of the attachment
means.
[0042] According to one embodiment, the attachment means are at
least two in number.
[0043] Advantageously, the thermal and acoustic insulation means
allow the attachment feet of the compressor to pass through.
[0044] According to one embodiment, the compressor comprises an
acoustic insulation jacket covering the body of the compressor.
[0045] The present invention also relates to a thermodynamic
machine using at least one compressor as described above.
BRIEF DESCRIPTION OF THE DRAWINGS
[0046] In any case, the invention will be clearly understood with
the aid of the following description, with reference to the
appended schematic drawing, representing, as a nonlimiting example,
an embodiment of a compressor according to the invention.
[0047] FIG. 1 is a general view in perspective.
[0048] FIG. 2 is a view in section on a larger scale along II-II of
FIG. 1.
[0049] FIG. 3 represents a partial exploded view in perspective of
the compressor of FIG. 1.
[0050] FIG. 4 represents schematically an acoustic emission
spectrum of a compressor according to the prior art.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0051] A compressor 2 intended to compress coolant fluid for a
refrigeration or air conditioning installation according to the
invention is represented in FIGS. 1 to 3. This compressor comprises
a substantially vertical body 3 comprising a casing 4 intended to
receive in particular a lubricating liquid 5 in its bottom portion
forming a reservoir.
[0052] In this embodiment, the compressor casing comprises a side
wall 11 and a base plate 6 having a dish-shaped central portion 7,
intended to form the bottom wall of the casing, bordered by a
peripheral rim 8, also comprising attachment orifices 9 for first
means of attachment 10 to a support 12, situated outside the
peripheral rim 8, and a return 13 made on the edge of the plate 6
and directed downward.
[0053] The side wall 11 and the base plate 6 are attached at the
rim 8, the lower edge of the side wall 11 resting on the outside of
the rim 8 forming an abutment.
[0054] The first attachment means 10 consist, in a known manner, of
a stud made of elastic material 14 of the rubber type forming a
supporting foot for the compressor and having a longitudinal
opening in which can be housed a bolt 15 intended to be housed also
in an opening 16 of the support 12.
[0055] According to an essential feature of the invention, the
compressor 2 comprises means 17 of heating the lubricating liquid
5, placed close to the bottom wall 7 of the casing, and acoustic
insulation and thermal insulation means 18 placed beneath the
heating means 17.
[0056] The heating means consist of an electric resistance 17
attached to the bottom wall 7 of the casing, outside the latter,
attached to the bottom wall of the casing by adhesive means 19, and
intended to be connected to an external source of electric power by
two connecting conductor wires 20.
[0057] The acoustic insulation and thermal insulation means 18
consist of a member having a top surface whose shape substantially
complements that of the bottom wall of the casing 7, comprising the
following elements, superposed from the bottom up: [0058] a flat
rigid support plate 22, [0059] a layer of cellular insulating
material 23, whose shape substantially complements that of the
bottom wall 7 of the casing, [0060] a film 24 made of plastic
material, protecting and keeping the cellular material in position,
the film being bonded or heat sealed to the flat plate 22 on the
periphery of the latter.
[0061] According to a variant, the layer of insulating material
comprises felt.
[0062] According to another variant, the layer of insulating
material comprises a fibrous material, such as glass fiber or rock
wool.
[0063] The thermal insulation and acoustic insulation means 18 are
held in position relative to the compressor body by second
attachment means 25 each comprising an elastic clip 26 held in
position by gripping the return 13 of the compressor base plate 6
and a substantially horizontal lug 27, the flat and rigid plate 22
supporting the thermal and acoustic insulation means resting on the
lugs 27 of the second attachment means 25.
[0064] These second attachment means 25 are four in number and
preferably at least two in number depending on the variants.
[0065] These second attachment means are used to make it easier to
install and remove the thermal and acoustic insulation means 18
on/from the compressor body 2.
[0066] The thin insulation means 18 are thus held in position
beneath the compressor, without contact with the support 12, and
delimit a housing for the heating means with the thin bottom wall
of the casing.
[0067] This disposition is particularly helpful in protecting the
heating means 17 from the effects of the wind, which cannot cause a
major heat loss. In addition, the heating means are placed beneath
the casing, thus making it possible to cause in the latter a
uniform temperature mix of the lubricating liquid by convection
currents.
[0068] Furthermore, the thermal and acoustic insulation means 18
are separated from the support, which assists with this
insulation.
[0069] It is therefore possible to maintain a temperature with an
electric power of the order of 50 to 60 W, hence much less than
that of the devices of the prior art, thus allowing a smaller
dimensioning of the heating means power supply circuit.
[0070] The thermal and acoustic insulation means 18 have a
horizontal cross section allowing the compressor attachment feet 14
to pass through.
[0071] In a known manner, the acoustic emission spectrum of a
compressor according to the prior art has a curve as shown in FIG.
4, the power P being represented on the y axis and the frequency F
on the x axis.
[0072] It appears on this curve that the compressor has a
considerable emitted power in a frequency band situated around 600
Hz.
[0073] The dispositions according to the invention make it possible
to obtain a reduction in the emitted power in this band, the
attenuation being of the order of -5 dBa.
[0074] This result is important, because the insulation jackets
covering the whole compressor body do not make it possible to
obtain a significant attenuation in this frequency band.
[0075] According to a variant, the compressor also comprises an
acoustic insulation jacket 28 shown in dot-and-dash lines covering
the compressor body 2.
[0076] The addition of this jacket makes it possible to obtain an
attenuation of the order of -7 dBa, in a frequency band situated
above 900 Hz.
[0077] The addition of this jacket on the compressor according to
the invention makes it possible to obtain an overall attenuation of
the order of -14 dBa across the whole spectrum.
[0078] This unexpected result is obtained thanks to the action of
the insulation means on one frequency band, and to the action of
the jacket on a different frequency band.
[0079] As it goes without saying, the invention is not restricted
to the preferred embodiment described hereinabove, as a nonlimiting
example; on the contrary it embraces all the variant embodiments
thereof in the context of the following claims.
[0080] Thus, it is possible to use several different layers of
insulating materials.
[0081] Also, the measurements taken for one embodiment of the
invention are cited as an example; these measurements may be
different for other embodiments.
* * * * *