U.S. patent application number 10/433445 was filed with the patent office on 2004-04-22 for refrigeration appliance with a plurality of storage compartments.
Invention is credited to Bresin, Lucio, Da Dalt, Massimo, Lotto, Lorenzo, Peruzzo, Roberto.
Application Number | 20040074247 10/433445 |
Document ID | / |
Family ID | 11453196 |
Filed Date | 2004-04-22 |
United States Patent
Application |
20040074247 |
Kind Code |
A1 |
Peruzzo, Roberto ; et
al. |
April 22, 2004 |
Refrigeration appliance with a plurality of storage
compartments
Abstract
Refrigeration appliance comprising at least two storage
compartments (10, 11) and a refrigerating circuit comprising a
compressor (14), a condenser (15), valve means (18, 19) and two
evaporators (12, 13). The compressor (14) is a variable-capacity
compressor, and said valve means are constituted by a
unidirectional valve (18) and a flow-diverting valve (19) to
selectively feed said evaporators via respective throttle means
(16, 17). The result is a sensible energy saving effect in the
operation of the appliance.
Inventors: |
Peruzzo, Roberto; (Porcia,
IT) ; Bresin, Lucio; (Pordenone, IT) ; Da
Dalt, Massimo; (Cappella Maggiore, IT) ; Lotto,
Lorenzo; (Boara Polesine, IT) |
Correspondence
Address: |
PEARNE & GORDON LLP
1801 EAST 9TH STREET
SUITE 1200
CLEVELAND
OH
44114-3108
US
|
Family ID: |
11453196 |
Appl. No.: |
10/433445 |
Filed: |
September 26, 2003 |
PCT Filed: |
October 5, 2001 |
PCT NO: |
PCT/EP01/11522 |
Current U.S.
Class: |
62/199 ;
62/525 |
Current CPC
Class: |
F25B 2600/0251 20130101;
F25B 2600/2511 20130101; F25D 2400/04 20130101; F25B 5/04 20130101;
F25D 11/022 20130101; F25B 41/37 20210101; F25B 49/025 20130101;
F25B 2600/2519 20130101; Y02B 40/00 20130101; F25B 2600/025
20130101 |
Class at
Publication: |
062/199 ;
062/525 |
International
Class: |
F25B 005/00; F25B
039/02 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 4, 2000 |
IT |
PN2000A000074 |
Claims
1. Refrigeration appliance, in particular of the household type,
comprising at least two storage compartments (10, 11) adapted to
hold and preserve food products at different temperatures, as well
as a refrigerating circuit comprising a compressor (14), a
condenser (15), valve means (18, 19) for diverting the flow of
refrigerant medium, and an evaporator (12, 13) arranged in each one
of said compartments, in which said evaporators are connected in
series with each other, characterized in that said compressor (14)
is a variable-capacity compressor, and that said valve means are
constituted by a unidirectional valve (18) and a flow-diverting
valve (19) to selectively feed said evaporators via respective
throttle means (16, 17).
2. Refrigeration appliance according to claim 1, characterized in
that said throttle means (16, 17) are capillary tubes ensuring
different flow rates, in which the capillary tube (16) associated
to the evaporator (12) of the cold storage compartment has a
greater flow rate than the capillary tube (17) associated to the
evaporator (13) of the freezing compartment.
3. Refrigeration appliance according to claim 1 or 2, characterized
in that the compressor (14) is provided with its own automatic
control logic arrangement adapted to autonomously select the
operating speed thereof on the basis of a combination of the
working percentages of the two compartments (10, 11) of the
refrigeration appliance and the ON-periods of the same
compartments, while privileging the one that requires the longest
operating time.
Description
DESCRIPTION
[0001] The present invention refers to a refrigeration appliance,
in particular of the household type, comprising at least two
storage compartments intended to hold and preserve food products at
different temperatures.
[0002] Refrigeration appliances provided with a cold storage, ie.
refrigerated compartment and a freezer compartment are largely
known in the art. These appliances are practically provided with
either two separated refrigerating circuits, ie. a circuit for each
compartment, or a single refrigerating circuit comprising two
evaporators that are adapted to be fed selectively through a valve
that diverts the flow of the refrigerant medium so as to
appropriately respond to the demands for cold in the two
compartments of the appliance. The first one of these solutions is
of course the most expensive one, owing to the duplication of the
circuits and, as a result, the component parts associated
therewith. The second solution, on the contrary, has a lower
efficiency, as well as an unsatisfactory behaviour in terms of
effectiveness.
[0003] The patent publication EP 0 246 465 describes a
refrigerating circuit for household refrigeration appliances that
essentially comprises a compressor, a condenser and two evaporators
arranged in series in a cold storage compartment and a freezing
compartment, respectively. The compressor is of the rotary type,
featuring a high starting torque. As a result, in view of
preventing the pressures from getting balanced throughout the
circuit during the switch-off periods of the compressor, the
addition to such a circuit of a thermostatically controlled
electromagnetic valve is proposed, which is provided with an inlet
from the condenser and two outlets towards the evaporators. The two
outlets of the electromagnetic valve may be both closed when the
compressor is switched off, and may be selectively opened when the
compressor is on the contrary switched on and operating. The
solution described in this patent has however turned out to be just
a theoretical, ie. practically unfeasible one, since an
electromagnetic valve arrangement of such a kind is quite difficult
to implement and would in any case involve an additional energy
usage for the actuation and operation thereof,
[0004] The much more recent patent specification WO 00/49344
proposes again a solution similar to the one disclosed in the above
cited publication EP 0 246 465, however without defining the type
of compressor used, while on the other hand describing a valve
solely in terms of operation and not construction.
[0005] In particular, when the evaporators are arranged in series
(FIG. 4), it is practically impossible to understand how the valve
1 in its position S3 may be able to solely feed the evaporator 5B.
In such a position of the valve, in fact, it seems practically
unavoidable for almost all of the refrigerant medium to also flow
through the evaporator 5A, thereby feeding both evaporators.
Actually, the solution disclosed in this patent still represents
just a further, albeit merely theoretical attempt towards achieving
a refrigeration appliance ensuring a reduced energy usage through
the optimisation of the refrigerating circuit thereof.
[0006] Such an aim can on the contrary be reached according to the
present invention by making use of the combination of a new type of
variable-capacity compressor (ie. a compressor with variable
refrigeration power or capacity) and a new valve solution, as
defined in the appended claims.
[0007] Features and advantages of the present invention will anyway
be more readily understood from the description that is given below
by way of non-limiting example with reference to the accompanying
drawings, in which:
[0008] FIG. 1 is a schematical view of the most recent prior-art
solution according to WO 00/49344;
[0009] FIG. 2 is a schematical cross-sectional view of a
refrigeration appliance provided with a refrigerating circuit
according to the present invention;
[0010] FIG. 3 is a diagrammatical view of the pattern of cold
demand versus temperature changes in the cold storage and freezing
compartments of the refrigeration appliance illustrated in FIG.
1.
[0011] As already stated above, the most recent prior art is
represented is FIG. 1, which illustrates a refrigerating circuit
with a compressor 2, a condenser 3 and two evaporators 5a and 5b
arranged in series. Between the condenser 3 and the evaporators 5a
and 5b there is provided a three-way valve 1. When in its position
S1, this valve shuts the passage of refrigerant medium towards both
evaporators. When in its position S2, the valve then allows the
refrigerant medium to flow first through the evaporator 5a and then
through the evaporator 5b. Finally, when in its position S3, the
valve should close the passage P2 towards the evaporator 5a, while
allowing the refrigerant medium to only flow through the evaporator
5b. This last situation, however, is frankly incomprehensible,
since the valve 1, so as illustrated, cannot close the passage P2.
In addition, even considering that a different type of valve might
be capable of implementing such an operating condition of the
circuit, the refrigerating circuit would certainly prove impossible
to balance in a correct manner, owing to the two evaporators
requiring considerably different amounts of cold.
[0012] The solution according to the present invention is
illustrated schematically in FIG. 2, which shows a refrigeration
appliance comprising a cold storage or refrigerating compartment 10
and a freezing compartment 11, each one of them being provided with
a respective evaporator 12 and 13. The two evaporators are
connected in series in the refrigerating circuit, which also
comprises a compressor 14 and a condenser 15. Each evaporator is
furthermore associated to a respective throttle, or capillary tube,
16 and 17.
[0013] According to the invention, the compressor 14 is a
variable-capacity compressor, ie. a compressor with a variable
refrigerating capacity, and the regulation of the refrigerant
medium flow in the circuit is carried out with the aid of valve
means provided between the condenser 15 and the capillary tubes 16
and 17. More precisely, such valve means can be constituted by a
unidirectional valve 18 and a flow-diverting valve 19, both of them
controlled by two thermostats (not shown) arranged in the
compartments 10 and 11, respectively. The valve 18 enables the
passage of refrigerant medium to the evaporators to be opened or
closed. The valve 19, in turn, actually enables either both
evaporators to be fed in series or the refrigerant medium to be
only delivered to the evaporator 13 of the freezing compartment. It
will of course be appreciated that the two valves 18 and 19 might
well be replaced by a single three-way valve in the assumption that
a valve of such a kind, capable of ensuring a reliable operation
and a low energy usage, could actually be provided.
[0014] A correct equalization, or balance, of the refrigerating
circuit is then obtained by appropriately sizing the capillary
tubes 16 and 17 and, in particular, by having the capillary tube 16
ensuring a greater flow rate than the one of the capillary tube
17.
[0015] The actual energy saving effect, which by the way is the
real and main purpose of the proposed solution, is therefore
obtained through the combination of various elements.
[0016] The main one among these elements is constituted by the use
of a variable-capacity compressor 14, which is provided with its
own automatic control logic system capable of autonomously
selecting the operating speed (and, therefore, the required
refrigerating capacity) thereof on the basis of a combination (eg.
the arithmetical mean value) of the percentages of operation, or
running time, of the two compartments of the refrigeration
appliance and the ON-periods (or operating periods) of the same
compartments, by privileging the one that requires the longest
operating time.
[0017] FIG. 3 illustrates a diagram showing the demand of cold, ie.
heat-extraction requirement versus temperature variations in the
cold storage compartment and the freezing compartment (as indicated
in abscissas and ordinates, respectively). The letters A-H indicate
the operating ranges at the various speeds of the compressor (A
indicates the slowest speed, H the fastest speed). The rectangles
represent the adjustment or setting areas of the refrigeration
appliance at different room temperatures (Ta). The algorithm of the
automatic control logic of the compressor 14 may for instance be
based on following operation data:
1 OP. LEVELS SPEED RT (%) ON (min) A 1600 0 < 50 <90 B 1800
50 < 55 <90 C 2000 50 < 60 <90 D 2200 60 < 65 <90
E 2400 65 < 70 <90 F 2700 70 < 75 <180 G 3000 75 <
85 <180 H 3600 85 < 100 <180
[0018] where:
[0019] RT is the percentage of running time of the refrigeration
appliance, and
[0020] ON is the operating time of the same appliance.
[0021] A further element that enables a real energy saving effect
to be obtained is constituted by the utilization of the
pulse-controlled valves 18 and 19. The actuation of these valves
enables the circuit to be closed in the OFF periods of the
refrigeration appliance, thereby preventing hot refrigerant medium
from passing from the condenser 15 to the evaporators 12 and 13. In
addition, the valve 19 really enables the evaporators to be fed in
a selective manner, in accordance with the demand for cold, ie. the
heat-extraction requirements of the respective compartments of the
refrigeration appliance.
[0022] Finally, the differentiation in the flow-rate capacity of
the capillary tubes 16 and 17 enhances the flexibility of the
refrigerating circuit in view of delivering a refrigerating
capacity that actually meets the thermal load of the appliance in
connection with both the independent utilization of the two
compartments and the different conditions of the same compartments
(room temperature, thermostat settings, door openings, and the
like).
* * * * *