U.S. patent application number 13/130334 was filed with the patent office on 2012-11-01 for laundry washing and drying machine.
This patent application is currently assigned to Electrolux Home Products Corporation N.V.. Invention is credited to Alberto Bison, Gordon Elger, Jean-Yves Noel, Massimiliano Vignocchi.
Application Number | 20120272689 13/130334 |
Document ID | / |
Family ID | 40548703 |
Filed Date | 2012-11-01 |
United States Patent
Application |
20120272689 |
Kind Code |
A1 |
Elger; Gordon ; et
al. |
November 1, 2012 |
Laundry Washing and Drying Machine
Abstract
A laundry washing and drying machine (1) includes a casing (2)
and, inside the casing, a laundry container (3, 6) for housing the
laundry to be washed and dried, and a heat-pump-type, hot-air
generator (10) able to circulate a stream of hot air inside the
laundry-container (3, 6), and to heat up the washing water supplied
to said laundry container (3, 6). The hot-air generator (10)
includes a heat-pump assembly (21) which is provided with a first
air/refrigerant heat exchanger (23) which is located along the air
recirculating conduit (19) for heating up the airflow (f) directed
to the laundry container (3, 6). A second water/refrigerant heat
exchanger (24) is located out of the air recirculating conduit
(19), and heats up or cools down the water arriving from the
laundry container (3, 6). A third air/water heat exchanger (25) is
located along the air recirculating conduit (19), upstream of the
first air/refrigerant heat exchanger (23), for cooling the airflow
(f) arriving from the laundry container (3, 6). A water circulation
circuit (26) is provided for circulating the water stored in the
laundry container (3, 6) through the second water/refrigerant heat
exchanger (24) and the third air/water heat exchanger (25). A
hydraulic distributor (28) is provided for reversing, on command,
the flow of the refrigerant along the first air/refrigerant heat
exchanger (23), the refrigerant expansion device (27) and the
second water/refrigerant heat exchanger (24).
Inventors: |
Elger; Gordon; (Aachen,
DE) ; Bison; Alberto; (San Quirino, IT) ;
Vignocchi; Massimiliano; (Cordenons, IT) ; Noel;
Jean-Yves; (Sacile, IT) |
Assignee: |
Electrolux Home Products
Corporation N.V.
Brussel
BE
|
Family ID: |
40548703 |
Appl. No.: |
13/130334 |
Filed: |
September 3, 2009 |
PCT Filed: |
September 3, 2009 |
PCT NO: |
PCT/EP2009/006394 |
371 Date: |
June 4, 2012 |
Current U.S.
Class: |
68/20 |
Current CPC
Class: |
D06F 58/206 20130101;
D06F 39/04 20130101 |
Class at
Publication: |
68/20 |
International
Class: |
D06F 29/02 20060101
D06F029/02 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 21, 2008 |
EP |
08169589.2 |
Claims
1. A laundry washing and drying machine comprising a casing and,
inside the casing, a laundry container for housing the laundry to
be washed and dried, and a hot-air generator able to circulate a
stream of hot air inside said laundry container, and to heat up the
washing water stored into the laundry container; said hot-air
generator comprising an air recirculating conduit connected at both
ends to said laundry container; ventilating means able to produce,
along the recirculating conduit, an airflow (f) which flows through
the laundry container; and a heat-pump assembly which is able to
rapidly cool the airflow (f) coming out from the laundry container
for condensing the surplus moisture in said airflow (f), and then
to rapidly heat the airflow (f) returning back into said laundry
container; wherein said heat-pump assembly is a bi-directional
device and it comprises: a first and a second refrigerant heat
exchanger designed so that the refrigerant flowing through them can
alternatively release or absorb heat from other fluids
simultaneously flowing through said first and second heat
exchanger; and bi-directional refrigerant circulating means able to
circulate a refrigerant in succession through said first and second
heat exchanger while subjecting said refrigerant in succession to a
compression and an expansion in the passing from one of said
refrigerant heat exchangers to the other, so that alternatively the
first or the second refrigerant heat exchanger can receive a
high-pressure and high-temperature refrigerant while the other
refrigerant heat exchanger receives a low-pressure and
low-temperature refrigerant; said first refrigerant heat exchanger
being located along the air recirculating conduit, and being
designed so that the refrigerant arriving from the bidirectional
refrigerant circulating means and the airflow directed to the
laundry container flow through it simultaneously, allowing the
refrigerant to release or absorb heat to/from said airflow (f, f');
said second refrigerant heat exchanger being instead located out of
the air recirculating conduit, and being designed so that the
washing water arriving from the laundry container and the
refrigerant arriving from the bi-directional refrigerant
circulating means flow through it simultaneously, allowing the
refrigerant to release or absorb heat to/from said washing water;
the hot-air generator being also provided with: an air/water heat
exchanger which is located along the air recirculating conduit,
upstream of the first refrigerant heat exchanger, and is designed
so that the airflow arriving from the laundry container and the
water arriving from said second refrigerant heat exchanger flow
through it simultaneously, allowing the water to absorb heat from
the airflow; and with a water circulation circuit for circulating
the water stored into the laundry container through the second
refrigerant heat exchanger and the air/water heat exchanger.
2. A laundry washing and drying machine as claimed in claim 1,
wherein the hot-air generator is also provided with airflow control
means which are located along the air recirculating conduit for
putting, on command, said air recirculating conduit in
communication with the outside, for allowing the external air to
circulate through the first refrigerant heat exchanger.
3. A laundry washing and drying machine as claimed in claim 2,
wherein said airflow control means are also able to prevent air
circulation through the air/water heat exchanger, when the air
recirculating conduit is in communication with the outside.
4. A laundry washing and drying machine as claimed in claim 1,
wherein said ventilating means are located along the air
recirculating conduit, between the air/water heat exchanger and the
first refrigerant heat exchanger.
5. A laundry washing and drying machine as claimed in claim 4,
wherein said airflow control means comprise two three-way valves
which are located along the air recirculating conduit, on both
sides of the first refrigerant heat exchanger, so as to divide the
air recirculating conduit into two consecutive segments each of
which crosses a respective heat exchanger; both three-way valves
being designed to put the segment of the air recirculating conduit
that crosses the first refrigerant heat exchanger, in direct
communication, alternatively, with the outside or with the other
segment of the air recirculating conduit.
6. A laundry washing and drying machine as claimed in claim 5,
wherein a first of said two three-way valves is located between the
air/water heat exchanger and the ventilating means, and a second of
said two three-way valves is located between the first refrigerant
heat exchanger and the laundry container.
7. A laundry washing and drying machine as claimed in claim 1,
wherein said water circulation circuit comprises a first pipe
connecting the bottom of the laundry container to the inlet of the
second refrigerant heat exchanger; a second pipe connecting the
outlet of the second refrigerant heat exchanger to the inlet of the
air/water heat exchanger ; a third pipe connecting the outlet of
the air/water heat exchanger to the laundry container; and a water
circulating pump which is located along said first, said second or
said third pipe for sucking, on command, the washing water from the
bottom of the laundry container and circulating said water through
the second refrigerant heat exchanger and the air/water heat
exchanger, before feeding said water back into the laundry
container.
8. A laundry washing and drying machine as claimed in claim 1,
wherein said laundry container comprises a washing tub suspended in
a floating manner inside the casing, and a revolving drum for
housing the laundry to be washed and/or dried, and which is fixed
in an axially rotating manner inside the washing tub.
9. A laundry washing and drying machine as claimed in claim 7,
wherein said laundry washing and drying machine also comprises a
washing-water recirculating and draining circuit for sucking the
washing water from the bottom of the washing tub and feeding said
water back into the revolving drum, or alternatively feeding said
water into an external waste-water exhaust duct; said water
circulation circuit being integrated with said washing-water
recirculating and draining circuit.
10. A laundry washing and drying machine as claimed in claim 1,
wherein said bi-directional refrigerant circulating means comprise:
refrigerant compressing means for compressing a gaseous refrigerant
so that refrigerant pressure and temperature are much higher at the
outlet than at the inlet of the refrigerant compressing means; a
refrigerant expansion device which subjects the refrigerant flowing
from the first refrigerant heat exchanger to the second refrigerant
heat exchanger or vice versa, to a rapid expansion for reducing
pressure and temperature of said refrigerant; and an hydraulic
distributor which connects the refrigerant compressing means to
both the first and the second refrigerant heat exchanger, and is
structured for selectively putting the outlet of the refrigerant
compressing means in communication with the first heat exchanger,
alternatively, the second refrigerant heat exchanger, and the inlet
of the refrigerant compressing means in communication with the
other refrigerant heat exchanger, for selecting, on command, the
flow of the refrigerant along the first refrigerant heat exchanger,
the refrigerant expansion device and the second refrigerant heat
exchanger.
Description
[0001] The present invention relates to a laundry washing and
drying machine.
[0002] More specifically, the present invention relates to a
front-loading home laundry washing and drying machine, to which the
following description refers purely by way of example.
[0003] As is known, front-loading laundry washing and drying
machines generally comprise a substantially parallelepiped-shaped
outer box casing resting on the floor; a substantially bell-shaped
washing tub which is suspended in floating manner inside the casing
by means of a number of coil springs and shock-absorber, directly
facing a laundry loading and unloading opening formed in the front
face of the casing; a door hinged to the front face of the casing
to rotate to and from a closing position in which the door closes
the opening in the front face of the casing to seal the washing
tub; a substantially bell-shaped cylindrical revolving drum for
housing the laundry to be washed and dried, and which is housed
substantially horizontally inside the washing tub to rotate about
its longitudinal axis; and an electric motor for rotating the
revolving drum about its longitudinal axis inside the washing
tub.
[0004] Front-loading laundry washing and drying machines of the
above type also have a water supply and recirculating circuit for
supplying a given amount of tap water into the washing tub, and for
circulating said water into the washing tub during washing and
rinsing phases of the washing cycle; and a closed-circuit, hot-air
generator designed to circulate inside the washing tub a stream of
hot air with a low moisture content, and which flows through the
revolving drum and over the laundry inside the drum to rapidly dry
the laundry.
[0005] In some laundry washing and drying machines, the
closed-circuit, hot-air generator comprises an air recirculating
conduit having its two ends connected to the washing tub, on
opposite sides of the latter; an electric centrifugal fan located
along the recirculating conduit to produce, inside the latter, an
airflow which flows through the washing tub and the revolving drum;
and finally a heat-pump assembly having its two heat exchangers
located one after the other, along the air recirculating conduit.
The first air/refrigerant heat exchanger of the heat-pump assembly
provides for rapidly cooling the airflow arriving from the washing
tub to condense the surplus moisture in the airflow; whereas the
second air/refrigerant heat exchanger of the heat-pump assembly
provides for rapidly heating the airflow arriving from the first
heat exchanger and directed back to the washing tub, so that the
airflow re-entering into the washing tub is heated rapidly to a
temperature higher than or equal to that of the air flowing out of
the washing tub.
[0006] More specifically, the heat-pump assembly of the hot-air
generator comprises: [0007] a refrigerant reciprocating compressor
which subjects a refrigerant in the gaseous state to compression,
so that refrigerant pressure and temperature are much higher at the
outlet than at the inlet of the reciprocating compressor; [0008] a
first air/refrigerant heat exchanger through which the refrigerant
coming out from the compressor and the airflow entering into the
washing tub flow simultaneously, and which is designed so that the
refrigerant releases heat to the airflow entering into the washing
tub, while at the same time condensing in the liquid state; [0009]
a second air/refrigerant heat exchanger through which the
refrigerant flowing to the compressor and the airflow coming out
from the washing tub flow simultaneously, and which is designed so
that the refrigerant absorbs heat from the airflow arriving from
washing tub to cause condensation of the surplus moisture in the
airflow, while at the same time completely turning back into the
gaseous state; and [0010] a refrigerant expansion device which
subjects the refrigerant flowing from the first to the second
air/refrigerant heat exchanger to a rapid expansion, so that
pressure and temperature of the refrigerant entering in the second
air/refrigerant heat exchanger are much lower than pressure and
temperature of the refrigerant coming out from the first
air/refrigerant heat exchanger, thus turning the refrigerant back
into the gaseous state and completing the closed thermodynamic
cycle in opposition to the reciprocating compressor, which provides
for rapidly compressing the refrigerant.
[0011] Obviously, first and second air/refrigerant heat exchangers
of the heat-pump assembly are located along the air recirculating
conduit, so as that the second air/refrigerant heat exchanger
provides for rapidly cooling the airflow arriving from the washing
tub to condense the surplus moisture in the airflow, and the first
air/refrigerant heat exchanger provides for rapidly heating the
airflow arriving from the second air/refrigerant heat exchanger and
directed back to the washing tub, so that the airflow entering into
the tub is heated rapidly to a temperature higher than or equal to
that of the same air flowing out of the tub.
[0012] In addition to the above, in a few laundry washing and
drying machines, the first air/refrigerant heat exchanger of the
heat-pump assembly (i.e. the heat exchanger which heats up the
airflow directed back to the washing tub) is also used for heating
up the tap water necessary for performing the washing and rinsing
phases of the washing cycle.
[0013] Unluckily, this way of heating up the washing water is not
highly efficient because of the structure of the first heat
exchanger of the heat-pump-type, hot-air generator. This heat
exchanger, in fact, is structured for performing an optimal heat
exchange between two fluids in gaseous state (i.e. the dehumidified
air directed back to the washing tub and the refrigerant in the
gaseous state), and therefore it is unable to allow an optimal heat
exchange between a fluid in liquid state and a fluid in gaseous
state.
[0014] In other words, the first heat exchanger of the
heat-pump-type, hot-air generator is unable to speedy heat up the
washing water stored in the washing tub.
[0015] It is the aim of the present invention to improve energy
efficiency of the heat-pump-type, hot-air generator of the above
cited home laundry washing and drying machines.
[0016] According to the present invention, there is provided a
laundry washing and drying machine as claimed in claim 1 and
preferably, though not necessarily, in any one of the Claims
depending directly or indirectly on claim 1.
[0017] A non-limiting embodiment of the present invention will be
described by way of example with reference to the accompanying
drawings, in which:
[0018] FIG. 1 shows a perspective view, with parts in section and
parts removed for clarity, of a front-loading laundry washing and
drying machine in accordance with the teachings of the present
invention;
[0019] FIG. 2 shows a schematic view of the FIG. 1 laundry washing
and drying machine in a first working configuration;
[0020] FIG. 3 shows a schematic view of the FIG. 1 laundry washing
and drying machine in a second working configuration;
[0021] FIG. 4 shows a schematic view of a second embodiment of the
FIGS. 1-3 laundry washing and drying machine; and
[0022] FIG. 5 shows a schematic view of a third embodiment of the
FIGS. 1-3 laundry washing and drying machine.
[0023] With reference to FIG. 1, number 1 indicates as a whole a
laundry washing and drying machine comprising a preferably, though
not necessarily, parallelepiped-shaped outer box casing 2 resting
on the floor; a substantially bell-shaped washing tub 3 suspended
in floating manner inside casing 2 via a suspension system
comprising a number of coil springs 4 (only one shown in FIG. 1)
preferably, though not necessarily, combined with one or more
vibration dampers 5 (only one shown in FIG. 1); a substantially
bell-shaped cylindrical revolving drum 6 for housing the laundry to
be washed and/or dried, and which is fixed in axially rotating
manner inside washing tub 3 for rotating about its longitudinal
axis L; and an electric motor assembly 7 for rotating, on command,
revolving drum 6 about its longitudinal axis L inside washing tub
3.
[0024] In particular, in the example shown, laundry washing and
drying machine 1 is a front-loading home washing and drying
machine, therefore washing tub 3 is suspended substantially
horizontally inside casing 2, with the front opening of washing tub
3 directly faced to a laundry loading and unloading opening formed
in a front face 2a of casing 2. Revolving drum 6, in turn, is
housed into washing tub 3 so that its longitudinal axis L is
oriented substantially horizontally, and coincides with the
longitudinal axis of washing tub 3.
[0025] With reference to FIG. 1, laundry washing and drying machine
1 is also provided with a cylindrical elastic-deformable bellows 8
connecting the front opening of washing tub 3 to the laundry
loading and unloading opening formed in front face 2a of casing 2,
and with a door (not shown) hinged to front face 2a of casing 2 to
rotate to and from a closing position in which the door closes the
laundry loading and unloading opening in front face 2a to seal
washing tub 3.
[0026] Casing 2, washing tub 3, the suspension system, revolving
drum 6, electric motor assembly 7 and bellows 8 are commonly know
parts in the washing machine technical field, and therefore not
described in detail.
[0027] With reference to FIGS. 2 and 3, laundry washing and drying
machine 1 is also provided with a water supply and recirculating
system 9 for supplying a given amount of tap water into washing tub
3, and for circulating said water into washing tub 3 during washing
and rinsing phases of the washing cycle; and with a closed-circuit,
hot-air generator 10 designed to circulate inside washing tub 3 a
stream of hot air with a low moisture content, and which flows
through revolving drum 6 and over the laundry inside the drum to
rapidly dry the laundry.
[0028] More specifically, closed-circuit, hot-air generator 10
provides for gradually drawing air from washing tub 3; extracting
surplus moisture from the air drawn from washing tub 3; heating the
dehumidified air to a predetermined temperature, normally higher
than the temperature of the air from washing tub 3; and feeding the
heated, dehumidified air back into washing tub 3, where it flows
over, to rapidly dry, the laundry inside the revolving drum 6.
[0029] With reference to FIGS. 2 and 3, in the example shown
laundry washing and drying machine 1 is preferably, though not
necessarily, provided with a detergent drawer (not shown) which is
removably housed inside a seat on front face 2a of casing 2, and
which has at least one compartment for a given amount of detergent
and/or softener for use in the washing cycle. The seat communicates
directly with washing tub 3, and the water supply and recirculating
system 9 consists of a drawer flush circuit 11 which, on command,
feeds a given amount of tap water into the compartments of the
detergent drawer to flush the detergent and/or softener out of the
compartments and down into washing tub 3; and of a washing water
recirculating and draining circuit 12 which, on command, sucks the
washing water from the bottom of washing tub 3 and feeds said water
back into the revolving drum 6, or alternatively drains the water
accumulated into the washing tub 3 into a waste-water exhaust duct
(not shown) located out of the laundry washing and drying machine
1.
[0030] With reference to FIGS. 2 and 3, the drawer flush circuit 11
comprises at least one water supply pipe 13, which is connected to
the external water supply main M of the building in which the
washing machine is installed, and terminates directly over the
detergent drawer; and at least one electrically controlled on-off
valve 14 interposed between water supply pipe 13 and the water
supply main M to regulate the pressurized-water flow to the end of
water supply pipe 13, so as to sprinkle, on command, the
compartment/s of the detergent drawer.
[0031] In the example shown, electrically controlled on-off valve
14 is a conventional controlled-open-close solenoid valve 14.
[0032] As regards the washing water recirculating and draining
circuit 12, it comprises a water recirculating pipe 15 having a
first end in communication with the bottom of washing tub 3, and a
second end faced to, or connected in known manner to, the revolving
drum 6; an electrically operated water circulating pump 16 located
along water recirculating pipe 15 for sucking the washing water
from the bottom of washing tub 3 and pumping said water towards
revolving drum 6; water filtering means (not shown) located along
water recirculating pipe 15, preferably, though not necessarily,
upstream of pump 16; and an electrically controlled tree-way valve
17 which is located along water recirculating pipe 15, immediately
downstream of pump 16, for channeling, on command, the water
flowing along recirculating pipe 15 into a water draining pipe 18
which is in communication with the waste-water exhaust duct (not
shown) located out of the laundry washing and drying machine 1.
[0033] With reference to FIGS. 2 and 3, hot-air generator is a
heat-pump-type, hot-air generator and substantially comprises:
[0034] an air recirculating conduit 19, the two ends of which are
connected to washing tub 3 preferably, though not necessarily, on
opposite sides of the latter; [0035] an electrically operated
centrifugal fan 20, or other type of air circulating pump, located
along recirculating conduit 19 to produce, inside recirculating
conduit 19, an airflow f which flows into washing tub 3 and over
the laundry inside the revolving drum 6; and [0036] a heat-pump
assembly 21 which is able to rapidly cool the airflow f coming out
from washing tub 3 for condensing the surplus moisture in the
airflow f, and then to rapidly heat the airflow f returning back
into washing tub 3, so that the airflow entering into washing tub 3
is heated rapidly to a temperature higher than or equal to that of
the same air flowing out of the washing tub 3.
[0037] Heat-pump assembly 21 operates in the same way as a
traditional heat-pump--which is capable of transferring heat from
one fluid to another using an intermediate gaseous refrigerant
subjected to a closed thermodynamic cycle, the thermodynamic
principles of which are widely known and therefore not described in
detail--but, differently from known laundry washing and drying
machines, heat-pump assembly 21 is a bi-directional device and it
comprises: [0038] two refrigerant heat exchangers 23 and 24
designed so that the refrigerant flowing through them can
alternatively release or absorb heat from other fluids
simultaneously flowing through the corresponding heat exchangers 23
and 24; and [0039] bi-directional closed-circuit refrigerant
circulating means able to circulate a gaseous refrigerant in
succession through the two refrigerant heat exchangers 23 and 24,
while subjecting the gaseous refrigerant in succession to a
compression and an expansion in the passing from a heat exchanger
23, 24 to the other, so that alternatively one of the two
refrigerant heat exchangers 24 and 24 can receive a high-pressure
and high-temperature refrigerant while the other refrigerant heat
exchanger receives a low-pressure and low-temperature
refrigerant.
[0040] More specifically, refrigerant heat exchanger 23 is located
along air recirculating conduit 19, upstream of washing tub 3--and
preferably, thought not necessarily, downstream of centrifugal fan
20--, and is designed so that the refrigerant arriving from the
bi-directional closed-circuit refrigerant circulating means and the
airflow f directed to washing tub 3 flow through it simultaneously,
allowing the refrigerant to release or absorb heat to/from said
airflow f, thus rapidly heating or cooling the airflow f.
[0041] Instead, differently from known laundry washing and drying
machines, refrigerant heat exchanger 24 is located out of air
recirculating conduit 19, and is designed so that the washing water
arriving from revolving drum 3 and the refrigerant arriving from
the bi-directional closed-circuit refrigerant circulating means
flow through it simultaneously, allowing the refrigerant to release
or absorb heat to/from said washing water, thus rapidly heating or
cooling the washing water arriving from revolving drum 3; and
hot-air generator 10 is also provided with: [0042] an air/water
heat exchanger 25 which is located along air recirculating conduit
19, upstream of heat exchanger 23, and is designed so that the
airflow f arriving from washing tub 3 and the water arriving from
washing tub 3 or refrigerant heat exchanger 24 flow through it
simultaneously, allowing the water having a temperature lower than
that of the airflow f, to absorb heat from the airflow f thus
causing condensation of the surplus moisture in the airflow f; and
[0043] a water circulation circuit 26 which, on command, circulates
the washing water stored into washing tub 3 through, in sequence,
the refrigerant heat exchanger 24 and the air/water heat exchanger
25.
[0044] More specifically, with reference to FIGS. 2 and 3,
heat-pump assembly 21 comprises: [0045] an electrically powered
refrigerant compressing device 22 which subjects a gaseous
refrigerant to compression (e.g. adiabatic compression) so that
refrigerant pressure and temperature are much higher at the outlet
than at the inlet of compressing device 22; [0046] a first
air/refrigerant heat exchanger 23 which is located along air
recirculating conduit 19, upstream of washing tub 3--and
preferably, thought not necessarily, downstream of centrifugal fan
20--, and is designed so that the refrigerant coming out from
compressing device 22 and the airflow f entering into washing tub 3
flow through it simultaneously, allowing the refrigerant having a
temperature greater than that of the airflow f to release heat to
the airflow f, thus rapidly heating the airflow f to a temperature
preferably, thought not necessarily, higher or equal to the
temperature of the airflow f coming out of washing tub 3; [0047] a
second water/refrigerant heat exchanger 24 which is located out of
air recirculating conduit 19, and is designed so that the water
arriving from revolving drum 3 and the refrigerant flowing to the
inlet of compressing device 22 flow through it simultaneously,
allowing the refrigerant having a temperature lower than that of
the water, to absorb heat from the water thus causing the cooling
of the water to a temperature preferably, thought not necessarily,
lower or equal to the temperature of the airflow f coming out of
washing tub 3; and [0048] a throttling valve or similar refrigerant
expansion device 27 which subjects the refrigerant flowing from the
air/refrigerant heat exchanger 23 to the water/refrigerant heat
exchanger 24, or vice versa, to a rapid expansion so that pressure
and temperature of the refrigerant entering in the
water/refrigerant heat exchanger 24 (or the air/refrigerant heat
exchanger 23) are much lower than pressure and temperature of the
refrigerant coming out from the air/refrigerant heat exchanger 23
(or the water/refrigerant heat exchanger 24), thus completing the
closed thermodynamic cycle in opposition to the compressing device
22, which provides for rapidly compressing the refrigerant.
[0049] Heat-pump assembly 21 also comprises a number of suitable
connecting pipes which connect refrigerant compressing device 22,
air/refrigerant heat exchanger 23, water/refrigerant heat exchanger
24 and refrigerant expansion device 27 one to the other, so as to
form a closed circuit allowing the refrigerant coming out from the
outlet of compressing device 22 to flow through, in sequence,
air/refrigerant heat exchanger 23, refrigerant expansion device 27
and water/refrigerant heat exchanger 24, before returning to the
inlet of compressing device 22; and an electrically controlled
four-way hydraulic distributor 28 which connects compressing device
22 to both the air/refrigerant heat exchanger 23 and the
water/refrigerant heat exchanger 24.
[0050] The four-way hydraulic distributor 28 is structured for
selectively putting the outlet of compressing device 22 in direct
communication with the air/refrigerant heat exchanger 23 or,
alternatively, the water/refrigerant heat exchanger 24, and the
inlet of compressing device 22 in direct communication with the
other refrigerant heat exchanger 23 or 24, so as to select, on
command, the flowing direction of the refrigerant through the
air/refrigerant heat exchanger 23, the water/refrigerant heat
exchanger 24 and the refrigerant expansion device 27.
[0051] In other words, hydraulic distributor 28 is able to reverse,
on command, the normal flowing direction of the refrigerant along,
in sequence, the air/refrigerant heat exchanger 23, the refrigerant
expansion device 27 and the water/refrigerant heat exchanger 24.
Thus, when the outlet of compressing device 22 is directly
connected to water/refrigerant heat exchanger 24, the refrigerant
releases heat to the water arriving from washing tub 3 when flowing
through water/refrigerant heat exchanger 24, and absorbs heat from
the air circulating into the air recirculating conduit 19 when
flowing through air/refrigerant heat exchanger 23.
[0052] Refrigerant compressing device 22, refrigerant expansion
device 27, the electrically controlled four-way hydraulic
distributor 28, and the connecting pipes which connect compressing
device 22, heat exchanger 23, heat exchanger 24 and expansion
device 27 one to the other, define the bi-directional
closed-circuit refrigerant circulating means of heat-pump assembly
21.
[0053] The water/refrigerant heat exchanger 24 and the electrically
controlled four-way hydraulic distributor 28 are commonly know
parts in the heat-pump technical field, and therefore not described
in detail.
[0054] Similarly the air/water heat exchanger 25 is a commonly know
part in the washing machine technical field, and therefore not
described in detail.
[0055] As regards the water circulation circuit 26, in the example
shown it comprises a first pipe 29 connecting the bottom of washing
tub 3 to the inlet of water/refrigerant heat exchanger 24; a second
pipe 30 connecting the outlet of water/refrigerant heat exchanger
24 to the inlet of the air/water heat exchanger 25; a third pipe 31
connecting the outlet of air/water heat exchanger 25 to the bottom
of washing tub 3; and an electrically powered water circulating
pump 32 which is located along pipe 29 (or alternatively along pipe
30 or pipe 31) for sucking, on command, the washing water from the
bottom of washing tub 3 and circulating said water through, in
sequence, the water/refrigerant heat exchanger 24 and the air/water
heat exchanger 25, or vice versa, before feeding said water back
into washing tub 3.
[0056] With reference to FIGS. 2 and 3, in the example shown the
electrically operated centrifugal fan 20 is preferably, though not
necessarily, located between air/refrigerant heat exchanger 23 and
air/water heat exchanger 25; and hot-air generator 10 also
comprises electrically controlled air valves, air baffles or
similar airflow control means, which are able to put, on command,
the air recirculating conduit 19 in direct communication with the
outside, for allowing external air to circulate through
air/refrigerant heat exchanger 23. In addition to the above, said
airflow control means are preferably, though not necessarily, also
able to prevent, at the same time, the external air from
circulating through the air/water heat exchanger 25.
[0057] More specifically, in the example shown, hot-air generator
10 is provided with two three-way valves 33 and 34, which are
located along air recirculating conduit 19, on both sides of
air/refrigerant heat exchanger 23, so to divide air recirculating
conduit 19 into two consecutive segments, each of which crosses a
respective heat exchanger 23, 25. Both three-way valves 33 and 34
are designed to put the first segment of air recirculating conduit
19 that crosses air/refrigerant heat exchanger 23, in direct
communication with the outside or, alternatively, in direct
communication with the other segment of the air recirculating
conduit 19, so to allow external air to circulate through
air/refrigerant heat exchanger 23 while, at the same time,
preventing said external air from circulating through the air/water
heat exchanger 25.
[0058] In particular, in the example shown, three-way valve 33 is
preferably, though not necessarily, located between air/water heat
exchanger 25 and centrifugal fan 20, whereas three-way valve 34 is
preferably, though not necessarily, located between air/refrigerant
heat exchanger 23 and washing tub 3. This arrangement of valves 33
and 34 allows the use of centrifugal fan 20 for generating the
airflow f along the whole air recirculating conduit 19, or the
airflow f' along the segment of air recirculating conduit 19 that
crosses the air/refrigerant heat exchanger 23.
[0059] Operation of the laundry washing and drying machine will now
be described assuming that the bottom of washing tub 3 is empty of
water; that hydraulic distributor 28 is configured to put the
outlet of compressing device 22 in direct communication with the
air/refrigerant heat exchanger 23, and the inlet of compressing
device 22 in direct communication with the water/refrigerant heat
exchanger 24; and that both three-way valves 33 and 34 are in their
firs operative configuration in which they keep the air
recirculating conduit 19 isolated from the outside (i.e they
connect the two segments of the air recirculating conduit 19 one
another), and let the airflow f flow along the whole air
recirculating conduit 19.
[0060] At this point, when the user requests a combined washing and
drying cycle to be performed, the electronic central control unit
35 of the laundry washing and drying machine 1 opens the on-off
valve 14 of drawer flush circuit 11 to fill up the bottom of
washing tub 3 with an appropriate quantity of tap water.
[0061] With reference to FIG. 3, when tap water reaches the
predetermined level within washing tub 3, central control unit 35
[0062] closes valve 14; [0063] switches the hydraulic distributor
28 so as to put the outlet of compressing device 22 in direct
communication with the water/refrigerant heat exchanger 24, and the
inlet of compressing device 22 in direct communication with the
air/refrigerant heat exchanger 23; and finally [0064] switches
three-way valves 33 and 34 in their second operative configuration
so as to put the first segment of air recirculating conduit 19 that
crosses air/refrigerant heat exchanger 23, into communication with
the outside of the household appliance while, at the same time,
preventing free air circulation along the second segment of the air
recirculating conduit 19 that crosses air/water heat exchanger
25.
[0065] When hot-air generator 10 is configured for heating up the
water stored in washing tub 3, central control unit 35 switches on,
respectively, centrifugal fan 20, compressing device 22, and pump
32 of the water circulation circuit 26, to enable heat-pump
assembly 21 to transfer heat from the airflow f' circulating
through air/refrigerant heat exchanger 23 and arriving from the
outside of the household appliance, to the water circulating into
water circulation circuit 26 and directed back to washing tub
3.
[0066] Since at this moment no air flows through air/water heat
exchanger 25, all heat absorbed from the airflow f' arriving from
the outside is used for quickly heating up the tap water in washing
tub 3.
[0067] More specifically, the high-temperature and high-pressure
refrigerant coming out from compressing device passes through
hydraulic distributor 28 and reaches the water/refrigerant heat
exchanger 24, inside which the refrigerant releases heat to the tap
water arriving from the bottom of washing tub 3 and directed back
to washing tub 3. Within heat exchanger 24, therefore, the
high-temperature and high-pressure refrigerant arriving from
compressing device 22 heats up the water circulating into water
circulation circuit 26.
[0068] After leaving the water/refrigerant heat exchanger 24, the
high-pressure refrigerant coming out from compressing device 22
then passes through the refrigerant expansion device 27, wherein
the refrigerant is rapidly expanded so that pressure and
temperature of the refrigerant entering in the air/refrigerant heat
exchanger 23 are much lower than pressure and temperature of the
refrigerant coming out from the water/refrigerant heat exchanger
24.
[0069] Finally, when passing through the air/refrigerant heat
exchanger 23, the low-pressure and low-temperature refrigerant
arriving from expansion device 27 and flowing back to compressing
device 22 absorbs heat from the airflow f' circulating through
air/refrigerant heat exchanger 23, thus rapidly cooling the airflow
f' flowing along the segment of air recirculating conduit 19 that
crosses the air/refrigerant heat exchanger 23. Since no air flows
through the air/water heat exchanger 25, the air/water heat
exchanger 25 operates like a traditional water conduit, and the
temperature of the water arriving from the water/refrigerant heat
exchanger 24 and directed back to washing tub 3 remains unchanged.
In other words, all heat absorbed from the airflow f' arriving from
the outside is transferred to the tap water circulating into water
circulation circuit 26.
[0070] When the water inside washing tub 3 reaches the requested
temperature, central control unit 35 may either switch off the
hot-air generator 10 (i.e. centrifugal fan 20, compressing device
22 and pump 32) and start washing the laundry placed inside
revolving drum 6 with the heated up tap water, or may open again
on-off valve 14 to pour some more tap water into washing tub 3 and
continue heating the water within the tub.
[0071] With reference to FIG. 2, when the rising phase of the
combined washing and drying cycle is completed, central control
unit 35 switches again the hydraulic distributor 28 to put the
outlet of compressing device 22 in direct communication with the
air/refrigerant heat exchanger 23 and the inlet of compressing
device 22 in direct communication with the water/refrigerant heat
exchanger 24; and switches the three-way valves 33 and 34 back in
their first operative configuration to isolate the air
recirculating conduit 19 from the outside, and to let the airflow f
flow along the whole air recirculating conduit 19.
[0072] When hot-air generator 10 is configured for drying the
laundry inside revolving drum 6, central control unit 35 switches
on centrifugal fan 20, compressing device 22, and pump 32 of the
water circulation circuit 26, to enable heat-pump assembly 21 to
rapidly cool the airflow f coming out from washing tub 3 for
condensing the surplus moisture in the airflow f, and then to
rapidly heat the airflow f returning back into washing tub 3, so
that the airflow f entering into washing tub 3 is heated rapidly to
a temperature higher than or equal to that of the same air flowing
out of the washing tub 3.
[0073] In which case, the cold water flowing in the water
circulation circuit 26 is used for transferring heat from the
airflow f coming out from washing tub 3 to the refrigerant flowing
through the water/refrigerant heat exchanger 24.
[0074] More specifically, the high temperature and pressure
refrigerant coming out from compressing device 22 passes through
hydraulic distributor 28 and reaches the air/refrigerant heat
exchanger 23 inside which the refrigerant releases heat to the
airflow f flowing into the air recirculating conduit 19, back to
washing tub 3. Within heat exchanger 23, therefore, the
high-temperature and high-pressure refrigerant arriving from
compressing device 22 heats up the airflow f directed back into
washing tub 3.
[0075] After leaving the air/refrigerant heat exchanger 23, the
high-pressure refrigerant coming out from compressing device 22
then passes through the refrigerant expansion device 27, wherein
the refrigerant is rapidly expanded so that pressure and
temperature of the refrigerant entering in the water/refrigerant
heat exchanger 24 are much lower than pressure and temperature of
the refrigerant coming out from the air/refrigerant heat exchanger
23.
[0076] Finally, when passing through the water/refrigerant heat
exchanger 24, the low-pressure and low-temperature refrigerant
arriving from expansion device 27 and flowing back to compressing
device 22 absorbs heat from the water arriving from the bottom of
washing tub 3 and directed back to washing tub 3, thus rapidly
cooling the water circulating into the water circulation circuit 26
and directed to the air/water heat exchanger 25.
[0077] The cold water circulating into the water circulation
circuit 26 may consist in a given quantity of the rinsing water
previously used in the rinsing phase of the washing and drying
cycle, or may consist in a given quantity of fresh water provided
by the water supply and recirculating system 9 (namely the drawer
flush circuit 11).
[0078] Obviously, if the laundry washing and drying machine 1 is
requested to perform a sole drying cycle, the cold water
circulating into the water circulation circuit 26 consists
preferably, though not necessarily, in a given quantity of fresh
water provided by the water supply and recirculating system 9.
[0079] Since now the airflow f arriving from washing tub 3 flows
through the air/water heat exchanger 25, the cold water circulating
into the water circulation circuit 26 absorbs heat from the airflow
f arriving from washing tub 3, thus rapidly cooling the airflow f
to condense the surplus moisture in the airflow.
[0080] Obviously, the temperature of the washing water leaving the
air/water heat exchanger 25 and directed back to the
water/refrigerant heat exchanger 24 is slightly higher than the
temperature of the washing water arriving from the
water/refrigerant heat exchanger 24, and the increase in the water
temperature is due to the heat amount absorbed from the airflow f
arriving from washing tub 3. This heat amount is immediately
transferred to the refrigerant flowing back to compressing device
22 within the water/refrigerant heat exchanger 24.
[0081] In other words, during the drying cycle, the water flowing
into the water circulation circuit 26 only transfers heat from the
airflow f arriving from washing tub 3 to the low-pressure and
low-temperature refrigerant flowing back to compressing device
22.
[0082] In addition to the above, it is finally evident that the
bottom of washing tub 3 is structured to contain a sufficient
quantity of fresh or rinsing water to be used in the drying cycle,
and, at the same time, to prevent said fresh or rinsing water to
reach the revolving drum 6 and the laundry stored inside the
drum.
[0083] The particular structure of heat-pump assembly 21 has lots
of advantages. Firstly the heat exchange taking place in heat
exchanger 24 of heat-pump assembly 21 always involves a fluid in
gaseous state (i.e. the refrigerant) and a fluid in liquid state
(i.e. the washing water stored in washing tub 3), thus heat
exchanger 24 assures optimal heat-exchange performances both when
laundry is dried, and when washing water is heated up.
[0084] In addition to the above, if the air/water heat exchanger 25
is a water spray condenser 25, the washing water circulating in
water circulation circuit 26 can be used for capturing fluff or
lint particles in the airflow f arriving from washing tub 3.
[0085] Clearly, changes may be made to laundry washing and drying
machine 1 as described herein without, however, departing from the
scope of the present invention.
[0086] For example, with reference to FIG. 4, the water circulation
circuit 26 may be integrated in the water recirculating and
draining circuit 12, so as to reduce the number of water pumps.
[0087] More specifically, instead of selectively channeling into
water draining pipe 18 the water flowing along recirculating pipe
15, the tree-way valve 17 channels, on command, the water flowing
along recirculating pipe 15 directly into water pipe 29; and the
water recirculating and draining circuit 12 is provided with a
second electrically controlled tree-way valve 17' which is located
along water pipe 29 for channeling, on command, the water flowing
along pipe 29 into water draining pipe 18. In which case,
therefore, pump 16 can suck the washing water from the bottom of
washing tub 3 and feed said either towards revolving drum 6, or
towards water/refrigerant heat exchanger 24.
[0088] With reference to FIG. 5, in a further different embodiment,
the bi-directional closed-circuit refrigerant circulating means of
heat-pump assembly 21 may lack the electrically controlled four-way
hydraulic distributor 28, and may comprise instead two refrigerant
compressing devices 22 which are connected to heat exchanger 23 and
heat exchanger 24 via two electrically controlled three-way valves
36. The two refrigerant compressing devices 22 are in anti-parallel
one to the other, so that each three-way valves 36 communicates
with the inlet of a first refrigerant compressing device 22, and
with the outlet of a second refrigerant compressing device 22.
[0089] In this embodiment, the electronic central control unit 35
of the laundry washing and drying machine 1 controls both three-way
valves 36 so to selectively connect only one of the two refrigerant
compressing devices 22 to heat exchanger 23 and heat exchanger 24,
while keeping the other refrigerant compressing device 22
isolated.
* * * * *