U.S. patent application number 15/113058 was filed with the patent office on 2017-01-12 for compressor for a refrigeration circuit of a domestic refrigerator, domestic refrigerator with a compressor and method for operating a compressor of a domestic refrigerator.
The applicant listed for this patent is BSH HAUSGERATE GMBH. Invention is credited to CHRISTIAN MAYERSHOFER.
Application Number | 20170010025 15/113058 |
Document ID | / |
Family ID | 52394234 |
Filed Date | 2017-01-12 |
United States Patent
Application |
20170010025 |
Kind Code |
A1 |
MAYERSHOFER; CHRISTIAN |
January 12, 2017 |
Compressor For A Refrigeration Circuit Of A Domestic Refrigerator,
Domestic Refrigerator With A Compressor And Method For Operating A
Compressor Of A Domestic Refrigerator
Abstract
A compressor for a refrigeration circuit of a domestic
refrigerator includes a piston being moveable within a compression
chamber of a cylinder for compressing a refrigerant. The piston is
contactlessly mounted in radial direction relative to the cylinder
by a gas pressure bearing formed from the refrigerant. An inlet
valve regulates a volume flow of uncompressed refrigerant from a
low-pressure inlet of the compressor into the compression chamber
and an outlet valve regulates a volume flow of compressed
refrigerant from the compression chamber to a high-pressure outlet
of the compressor. A stop valve between the low-pressure inlet and
the high-pressure outlet prevents a backflow of refrigerant from
the high-pressure outlet to the low-pressure inlet when the
compressor is deactivated. A domestic refrigerator including a
compressor and a method for operating a compressor for a
refrigeration circuit of a domestic refrigerator are also
provided.
Inventors: |
MAYERSHOFER; CHRISTIAN;
(GUNDREMMINGEN, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
BSH HAUSGERATE GMBH |
Munchen |
|
DE |
|
|
Family ID: |
52394234 |
Appl. No.: |
15/113058 |
Filed: |
January 7, 2015 |
PCT Filed: |
January 7, 2015 |
PCT NO: |
PCT/EP2015/050150 |
371 Date: |
July 21, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F25B 2600/2519 20130101;
F04B 53/1082 20130101; F25B 2500/26 20130101; F25B 2600/01
20130101; F04B 53/16 20130101; F04B 53/14 20130101; F04B 39/10
20130101; F04B 35/045 20130101; F04B 49/03 20130101; F25B 1/02
20130101; F25B 41/04 20130101; F25B 2400/073 20130101; F04B 53/10
20130101 |
International
Class: |
F25B 1/02 20060101
F25B001/02; F04B 49/03 20060101 F04B049/03; F04B 53/10 20060101
F04B053/10; F04B 53/16 20060101 F04B053/16; F25B 41/04 20060101
F25B041/04; F04B 53/14 20060101 F04B053/14 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 21, 2014 |
DE |
10 2014 200 981.2 |
Claims
1-13. (canceled)
14. A compressor for a refrigeration circuit of a domestic
refrigerator, the compressor comprising: a low pressure inlet and a
high pressure outlet; a cylinder having a compression chamber; a
piston being movable within said compression chamber to compress a
refrigerant, said piston having a radial direction, and said piston
being contactlessly supported by a gas pressure bearing formed by
the refrigerant in said radial direction opposite said cylinder; an
inlet valve for regulating a volume flow of uncompressed
refrigerant from said low pressure inlet into said compression
chamber; an outlet valve for regulating a volume flow of compressed
refrigerant from said compression chamber to said high pressure
outlet; and a stop valve disposed between said low pressure inlet
and said high pressure outlet, for preventing the refrigerant from
flowing back from said high pressure outlet to said low pressure
inlet when the compressor is deactivated.
15. The compressor according to claim 14, which further comprises a
gas bearing supply pipe for feeding the refrigerant to form said
gas pressure bearing, said stop valve being disposed in said gas
bearing supply pipe.
16. The compressor according to claim 14, which further comprises a
refrigerant pipe for feeding the compressed refrigerant flow toward
said high pressure outlet when the compressor is activated, said
stop valve being disposed in said refrigerant pipe.
17. The compressor according to claim 14, wherein said stop valve
is a non-return valve.
18. The compressor according to claim 14, wherein said stop valve
is actuatable in an electromotive or electromagnetic manner.
19. The compressor according to claim 14, wherein the compressor is
a linear compressor.
20. The compressor according to claim 14, wherein said cylinder
includes a socket, and said piston is disposed within said
socket.
21. The compressor according to claim 20, wherein said socket has a
plurality of openings formed therein, through which the refrigerant
can be fed toward said piston to form said gas pressure
bearing.
22. A domestic refrigerator, comprising a compressor according to
claim 14.
23. The domestic refrigerator according to claim 22, which further
comprises: a refrigeration circuit having a flow direction, an
evaporator and a condenser said compressor being disposed
downstream of said evaporator and upstream of said condenser in
said flow direction; and a further stop valve disposed downstream
of said condenser and upstream of said evaporator in said flow
direction.
24. A method for operating a compressor of a refrigeration circuit
of a domestic refrigerator, the method comprising the following
steps: contactlessly supporting a piston in radial direction of the
piston relative to a cylinder by using a gas pressure bearing
formed of a refrigerant; compressing the refrigerant by moving the
piston within a compression chamber of the cylinder; actuating a
compressor inlet valve for regulating a volume flow of uncompressed
refrigerant from a low pressure compressor inlet into the
compression chamber; actuating a compressor outlet valve for
regulating a volume flow of compressed refrigerant from the
compression chamber to a high pressure compressor outlet; and
closing a stop valve disposed between the low pressure compressor
inlet and the high pressure compressor outlet as soon as the
compressor is deactivated, to prevent a backflow of the refrigerant
from the high pressure compressor outlet to the low pressure
compressor inlet when the compressor is deactivated.
25. The method according to claim 24, which further comprises
opening the stop valve according to a predetermined timeline,
before the deactivated compressor for compressing the refrigerant
is activated again.
26. The method according to claim 25, which further comprises
selecting the timeline before activating the compressor to be so
great that the gas pressure bearing between the piston and the
cylinder is formed by the refrigerant flowing into the compressor
from the high pressure outlet.
Description
[0001] The invention relates to a compressor for a refrigeration
circuit of a domestic refrigerator and a method for operating a
compressor of a domestic refrigerator of the type specified in the
preamble of the independent claims. Furthermore, the invention
relates to a domestic refrigerator having a compressor of this
type.
[0002] WO 2008 055810 A1 shows a linear compressor for a domestic
appliance, having a piston which can move between an upper and
lower dead center position in the longitudinal direction of a
cylinder, the outer surface of the piston of which can be supported
in a contactless manner with respect to a corresponding inner
surface of the cylinder by forming a gas pressure bearing in the
radial direction of the cylinder. The linear compressor shown there
can be used in a refrigeration circuit of a domestic
refrigerator.
[0003] During a downtime of a compressor of this type with a gas
storage, said gas storage may result in an undesirable backflow of
gaseous refrigerant from a high pressure outlet to a low pressure
inlet of the compressor. The result is that a corresponding
pressure difference between the high pressure outlet and the low
pressure inlet during the downtime of a compressor of this type
cannot be maintained, which has a negative effect on the operation
of a refrigeration circuit of a domestic refrigerator. When a
compressor of this type is restarted, the pressure difference
between the high pressure outlet and the low pressure inlet of the
compressor must first be re-established.
[0004] It is therefore the object of the present invention to be
able to maintain a pressure difference between a low pressure inlet
and a high pressure outlet of a compressor even during the downtime
of the compressor.
[0005] This object is achieved by a compressor for a refrigeration
circuit of a domestic refrigerator and by a method for operating a
compressor of a refrigeration circuit of a domestic refrigerator
with the features of the independent claims and furthermore by a
domestic refrigerator with a compressor of this type.
[0006] The inventive compressor for a refrigeration circuit of a
domestic refrigerator comprises a piston which can be moved within
a compression chamber of a cylinder in order to compress a
refrigerant, wherein in its radial direction relative to the
cylinder the piston can be supported in a contactless manner by
means of a gas pressure bearing which can be formed from the
refrigerant. Moreover, the compressor comprises an inlet valve for
regulating a volume flow of uncompressed refrigerant from a low
pressure inlet of the compressor into the compression chamber. The
compressor also comprises an outlet valve for regulating a volume
flow of compressed refrigerant from the compression chamber to a
high pressure outlet of the compressor. In order to be able to
maintain a pressure difference between the low pressure inlet and
the high pressure outlet of the compressor which was established
during operation of the compressor even during the downtime of the
compressor, provision is inventively made for the compressor to
comprise a stop valve arranged between the low pressure inlet and
the high pressure inlet, which is designed to prevent a backflow of
refrigerant from the high pressure outlet to the low pressure inlet
when the compressor is deactivated.
[0007] Provision is therefore made in accordance with the
invention, in addition to the inlet valve and the outlet valve,
which serve to regulate the volume flows of refrigerant through the
compressor, to provide a further stop valve within the compressor
between the low pressure inlet and the high pressure outlet, by
means of which it is possible to prevent refrigerant from flowing
through the compressor when the compressor is deactivated. During
operation of the compressor, a pressure difference is established
between the low pressure inlet and the high pressure outlet, which,
during deactivation of the compressor by a backflow of refrigerant
through the compressor would result in an undesirable pressure
compensation. The inventively provided stop valve now enables this
undesirable pressure compensation between the low pressure inlet
and the high pressure outlet of the compressor to be prevented by
the stop valve being closed once the compressor is deactivated.
Even during the downtime of the compressor the inventive solution
enables a previously established pressure difference between the
low pressure inlet and the high pressure outlet of the compressor
to be maintained, which allows a significant increase in efficiency
of a refrigeration circuit of a domestic refrigerator to be
achieved, in which the inventive compressor is used. When the
compressor is restarted, it is namely no longer necessary by means
of the inventive solution to firstly establish a pressure
difference between the low pressure inlet and the high pressure
inlet, since the pressure difference established previously during
operation of the compressor by the closable stop valve can also be
reliably maintained during the downtime of the compressor.
[0008] Provision is made in an advantageous embodiment for the stop
valve to be arranged in a gas bearing supply pipe of the
compressor, through which the refrigerant can be fed in order to
form the gas pressure bearing. In other words the stop valve can be
arranged directly in the gas bearing supply pipe of the compressor
which serves as a pressure pipe, as a result of which when the
compressor is disconnected a pressure compensation can be prevented
by a backflow of refrigerant through the gas bearing supply
pipe.
[0009] Provision is made in a further advantageous embodiment of
the invention for the stop valve to be arranged in a refrigerant
pipe of the compressor, through which refrigerant pipe the
compressed refrigerant flows in the direction of the high pressure
outlet when the compressor is activated. The accessibility of a
refrigerant pipe of this type may be better in some instances than
with the gas bearing supply pipe, so that a potentially defective
stop valve can be exchanged particularly easily. With the
arrangement of the stop valve in the refrigerant pipe, which leads
to the high pressure outlet of the compressor, an undesirable
pressure compensation between the high pressure outlet and the low
pressure inlet of the compressor can likewise be effectively
prevented when the compressor is deactivated.
[0010] According to a further advantageous embodiment of the
invention, provision is made for the stop valve to be embodied as a
non-return valve. For instance, the stop valve can be embodied as a
lamellar valve, spring valve or suchlike, which can be actuated
solely by the pressure difference between the low pressure inlet
and the high pressure outlet of the compressor. A stop valve of
this type is typically of a relatively simple design and can
therefore be manufactured and provided in a particularly
cost-effective manner.
[0011] Provision is made in a further advantageous embodiment of
the invention for the stop valve to be actuateable in an
electromotive or electromagnetic manner In other words, provision
can be made for the stop valve to be an active element, with which
the valve position can be influenced by applying an electrical
current for instance. The advantage of an embodiment of this type
is that the stop valve can be actively actuated, as a result of
which its actuation can be freely selected essentially
independently of the pressure ratios prevailing within the
compressor.
[0012] A further advantageous embodiment of the invention provides
that the compressor is embodied as a linear compressor. Linear
compressors are typically piston compressors, in which the pistons
are driven by linear drives, for instance roller thread gears,
independently of a crankshaft. Compared with conventional piston
compressors with a rotary drive, for instance by way of a
connecting rod driven by a rotation motor, linear compressors have
the advantage that the piston stroke can be changed. This enables
the compression ratio within the compressor to be adjusted
particularly easily to suit requirements.
[0013] Provision is made in a further advantageous embodiment of
the invention for the cylinder to comprise a socket, within which
the piston is arranged. If the gas pressure bearing is not able to
be formed on account of a defect for instance, the piston only
achieves contact with the socket, within which it is guided, so
that in a case of this type only the socket is damaged and has to
be replaced.
[0014] A further advantageous embodiment of the invention provides
that the socket comprises a number of openings, through which the
refrigerant can be supplied in the direction of the piston in order
to form the gas pressure bearing. These openings are preferably
provided evenly distributed on the socket, so that the gas pressure
bearing can be set up particularly quickly and evenly.
[0015] The domestic refrigerator according to the invention
comprises the inventive compressor or an advantageous embodiment of
the inventive compressor.
[0016] According to an advantageous embodiment of the domestic
refrigerator, provision is made for the compressor to be arranged
downstream of an evaporator and upstream of a condenser in the flow
direction of a refrigeration circuit of the domestic refrigerator,
wherein a further stop valve is arranged downstream of the
condenser and upstream of the evaporator in the flow direction.
Here the flow direction is understood to mean the flow direction of
the refrigerant within the refrigeration circuit, in which the
refrigerant flows through the refrigeration circuit when the
compressor is activated. As a result of a further stop valve being
arranged downstream of the condenser and upstream of the
evaporator, an undesirable pressure compensation between the
condenser and the evaporator can be prevented when the compressor
is deactivated, since the condenser represents a high-pressure side
and the evaporator a low-pressure side of the refrigeration
circuit. This likewise contributes to increased efficiency of the
refrigeration circuit of the domestic refrigerator, because a
pressure compensation between the condenser and the evaporator can
be prevented by closing the further stop valve.
[0017] With the inventive method for operating a compressor of a
refrigeration circuit of a domestic refrigerator, a refrigerant is
compressed by means of a piston that can be moved within a
compression chamber of a cylinder, which, in its radial direction
with respect to the cylinder, is supported in a contactless manner
by means of a gas pressure bearing formed from the refrigerant.
Here an inlet valve of the compressor is actuated in order to
regulate a volume flow of uncompressed refrigerant from a low
pressure inlet of the compressor into the compression chamber.
Furthermore, an outlet valve of the compressor is actuated in order
to regulate a volume flow of compressed refrigerant from the
compression chamber to a high pressure outlet of the compressor.
The inventive method is characterized here in that a stop valve
arranged between the low pressure inlet and the high pressure
outlet is closed as soon as the compressor is deactivated, wherein
a backflow of refrigerant from the high pressure outlet to the low
pressure inlet is prevented when the compressor is deactivated.
Advantageous embodiments of the inventive compressor are to be
considered here as advantageous embodiments of the inventive method
for operating a compressor of this type.
[0018] Provision is made in a further advantageous embodiment of
the method for the stop valve to be opened with a predetermined
timeline before the deactivated compressor is activated again in
order to compress the refrigerant. The timeline before activating
the compressor is preferably selected to be so great that the gas
pressure bearing between the piston and the cylinder is fully
formed by means of the refrigerant flowing into the compressor from
the high pressure outlet. In other words, the stop valve is opened
with respect to a prevailing drop in pressure when the compressor
is deactivated so that on account of the prevailing drop in
pressure between the high pressure outlet and the low pressure
inlet of the compressor, the refrigerant flows into the compressor
and the gas pressure bearing is formed between the piston and the
cylinder, even before the compressor is activated again. As a
result, the piston can already be supported in a contactless manner
in respect of the cylinder before the compressor is activated. As a
result, the wear on the piston-cylinder pairing can be
significantly reduced.
[0019] Further advantages, features and details of the invention
result from the description of preferred exemplary embodiments
which follows and with the aid of the drawing. The features and
feature combinations mentioned above in the description and the
features and feature combinations mentioned below in the
description of the figures and/or simply shown in the figures can
be used not only in the combination specified in each instance but
also in other combinations or alone without departing from the
scope of the invention.
[0020] The drawings show in:
[0021] FIG. 1 a schematic longitudinal section of a domestic
refrigerator with a compressor;
[0022] FIG. 2 a schematic representation of a refrigeration circuit
of the domestic refrigerator within which the compressor is
arranged;
[0023] FIG. 3 a schematic lateral sectional view of a first
exemplary embodiment of the compressor, and
[0024] FIG. 4 a schematic lateral sectional view of a second
exemplary embodiment of the compressor.
[0025] Similar or functionally similar elements are provided with
the same reference characters in the figures.
[0026] A domestic refrigerator 10 is shown in FIG. 1 in a schematic
longitudinal section. The domestic refrigerator 10 may be
refrigerator, a freezer or a refrigerator-freezer for instance. The
domestic refrigerator 10 comprises an interior 12 which is embodied
to receive groceries. This interior 12 may be a refrigerator
compartment, a freezer compartment or a NoFrost compartment or have
at least two of these compartments.
[0027] The domestic refrigerator 10 comprises a refrigeration
circuit 14, which has a compressor 16 embodied as a linear
compressor. The compressor 16 is preferably arranged in a machine
space 18, which is disposed in the lower and rear region of the
domestic refrigerator 10.
[0028] FIG. 2 shows the refrigeration circuit 14 in a schematic
representation. Aside from the compressor 16, the refrigeration
circuit 14 comprises a condenser 20, a throttle 22, which can also
be an expansion valve or suchlike, and an evaporator 24.
Furthermore, the compressor 16 comprises a stop valve 50, which is
mentioned in more detail hereinafter. Furthermore, the
refrigeration circuit 14 comprises a further stop valve 28. Arrow
30 indicates a flow direction of the refrigeration circuit 14, in
which a refrigerant (not shown) flows, provided the compressor 16
is activated.
[0029] The compressor 16 is therefore arranged downstream of the
evaporator 24 and upstream of the condenser 20 in the flow
direction 30 of the refrigeration circuit 14, wherein the further
stop valve 28 is arranged downstream of the condenser and upstream
of the evaporator 24 in the flow direction 30, in the present case
still upstream of the throttle 22.
[0030] FIG. 3 shows a schematic lateral sectional view of a first
exemplary embodiment of the compressor 16. The compressor 16
comprises a piston 36 which can be moved within a compression
chamber 32 of a cylinder 34 in order to compress a refrigerant (not
shown in more detail), wherein, in its radial direction relative to
the cylinder 34, the piston 36 can be supported in a contactless
manner by means of a gas pressure bearing which can be formed from
the refrigerant. The cylinder 34 currently comprises a socket 38,
within which the piston 36 is arranged. The socket 38 has a number
of openings 40 here, through which the refrigerant can be fed in
order to form the gas pressure bearing in the direction of the
piston 36.
[0031] Moreover, the compressor 16 comprises an inlet valve 42
which serves to regulate a volume flow of uncompressed refrigerant
from a low pressure inlet 44 of the compressor 16 into the
compression chamber 32. The low pressure inlet 44 is arranged on a
housing 35 of the compressor 16 and is connected within the
refrigeration circuit 14 to the evaporator 24, so that when the
compressor 16 is activated, the refrigerant is fed from the
evaporator 24 via the low pressure inlet 44 to the compressor
16.
[0032] The compressor 16 further comprises an outlet valve 46 for
regulating a volume flow of compressed refrigerant from the
compression chamber 32 to a high pressure outlet 48 of the
compressor 16, which is likewise arranged on the housing 35. The
high pressure outlet 48 is connected within the refrigeration
circuit 14 to the condenser 20. The compressed refrigerant is
therefore routed via the high pressure outlet 48 to the condenser
20.
[0033] The compressor 16 comprises a stop valve 50 arranged between
the low pressure inlet 44 and the high pressure outlet 48, which is
designed to prevent a backflow of refrigerant from the high
pressure outlet 48 to the low pressure inlet 44 when the compressor
16 is deactivated. In other words, the stop valve 50 can be closed
when the compressor 16 is deactivated, so that a pressure
difference established between the high pressure outlet 48 and the
low pressure inlet 44 during operation of the compressor 16 can be
maintained.
[0034] In this case the stop valve 50 is arranged in a gas bearing
supply pipe 52 of the compressor 16, through which the refrigerant
for forming the gas pressure bearing can be fed. The gas bearing
supply pipe 52 leads from a high-pressure side of the compressor 16
into a reservoir 41, from where the refrigerant can be fed through
the openings 40 of the socket 38 in the direction of the piston 36,
in order to form the gas pressure bearing between the piston 36 and
the socket 38.
[0035] The stop valve 50 can be embodied as a simple non-return
valve, for instance as a lamellar valve, spring valve or suchlike.
In this case, the stop valve 50 is independently closed by a
pressure difference between the high pressure outlet 48 and the low
pressure inlet 44 of the compressor 16. It is alternatively also
possible for the stop valve 50 to be embodied as an active element
and to be actuateable in an electromotive or electromagnetic manner
for instance.
[0036] FIG. 4 shows a schematic lateral sectional view of a further
exemplary embodiment of the compressor 16. Contrary to the
exemplary embodiment of the compressor 16 shown in FIG. 3, in the
present case shown, the stop valve 50 is arranged in a
high-pressure side refrigerant pipe 54 of the compressor 16,
through which the compressed refrigerant flows in the direction of
the high pressure outlet 48 when the compressor 16 is
activated.
[0037] A method for operating the compressor 16 is explained below.
When the compressor 16 is activated, the refrigerant is compressed
by means of the piston 36 moved within the compression chamber 32
within the cylinder 34, wherein, in its radial direction with
respect to the cylinder 34, the piston 36 is supported in a
contactless manner by means of the gas pressure bearing formed from
the refrigerant. In this way refrigerant is continuously conveyed
into the gas reservoir 41 via the gas bearing supply pipe 52 and
fed through the openings 40 in the direction of the piston 36, as a
result of which the gas pressure bearing, which is formed from the
refrigerant, is supplied with an adequate pressure.
[0038] Provided the compressor 16 is in operation, the inlet valve
42 and the outlet valve 46 are actuated cyclically and alternately,
in order to regulate the volume flow of refrigerant from the low
pressure inlet 44 through the compression chamber 32 via the high
pressure outlet 48.
[0039] As soon as the compressor 16 is deactivated, the stop valve
50 arranged between the low pressure inlet 44 and the high pressure
outlet 48 is closed, as a result of which a backflow of refrigerant
from the high pressure outlet 48 to the low pressure inlet 44 is
prevented when the compressor 16 is deactivated. At the same time
the further stop valve 28, which, as shown in FIG. 2, is arranged
within the refrigeration circuit 14 between the condenser 20 and
the throttle 22, is closed as soon as the compressor 16 is
deactivated. As a result, a pressure compensation between the
condenser 20 and the evaporator 24 is prevented when the compressor
16 is deactivated since the refrigerant can no longer flow
downstream of the condenser 20 in the direction of the evaporator
24.
[0040] The stop valve 50 arranged within the compressor 16 is
opened with a predetermined timeline, before the deactivated
compressor 16 is activated again in order to compress the
refrigerant. Here the timeline before activating the compressor 16
is selected to be so great that the gas pressure bearing between
the piston 36 and the cylinder 34 is fully formed by means of the
refrigerant flowing into the compressor 16 from the high pressure
outlet 48, before the compressor 16 is activated again. This
ensures that the gas pressure bearing between the piston 36 and
cylinder 34 is fully formed before the compressor 16 is activated
again and the piston 36 moves within the cylinder 34 in order to
compress the refrigerant.
LIST OF REFERENCE CHARACTERS
[0041] 10 Domestic refrigerator [0042] 12 Interior [0043] 14
Refrigeration circuit [0044] 16 Compressor [0045] 18 Machine space
[0046] 20 Condenser [0047] 22 Throttle [0048] 24 Evaporator [0049]
28 Stop valve [0050] 30 Flow direction [0051] 32 Compression
chamber [0052] 34 Cylinder [0053] 35 Housing [0054] 36 Piston
[0055] 38 Socket [0056] 40 Opening [0057] 41 Reservoir [0058] 42
Inlet valve [0059] 44 Low pressure inlet [0060] 46 Outlet valve
[0061] 48 High pressure outlet [0062] 50 Stop valve [0063] 52 Gas
bearing supply pipe [0064] 54 Refrigerant pipe
* * * * *