U.S. patent application number 10/562186 was filed with the patent office on 2006-10-12 for absorption refrigerator with ice-maker.
This patent application is currently assigned to Dometic Sweden AB. Invention is credited to Anders Hallin.
Application Number | 20060225457 10/562186 |
Document ID | / |
Family ID | 27731068 |
Filed Date | 2006-10-12 |
United States Patent
Application |
20060225457 |
Kind Code |
A1 |
Hallin; Anders |
October 12, 2006 |
Absorption refrigerator with ice-maker
Abstract
Absorption refrigerator (1) including a cabinet having outer
walls (2, 3, 4, 5, 6) and at least one door (7, 8) encasing a low
temperature storage compartment (9) and a higher temperature
storage compartment (10), said compartments being separated by a
partition wall (11). An ice-maker is arranged in one of the
compartments. The refrigerator is cooled by an absorption
refrigerating system which includes an evaporator tube (20) in
which a refrigeration medium flows from an upstream end to a
downstream end of the evaporator tube, and which evaporator tube
comprises a first tube section (21) which is arranged to absorb
heat from the low temperature compartment, a' second tube section
(22), which is arranged to cool the higher temperature compartment
and a third tube section (23) which is arranged to cool the
ice-maker. The first, second and third tube sections are connected
in series and the first tube section is arranged upstream of the
second tube section. In order to minimize the negative influence of
the operation of the ice-maker on the temperature in the freezer
compartment, and to reduce the humidity influence of the ice-maker,
the third tube section is arranged downstream of said first tube
section and upstream of said second tube section and the ice
fabrication device is exposed to air circulating in the low
temperature compartment or in the higher temperature compartment
(10), and means are provided for melting frost generated by
humidity in said low temperature Compartment (9) or said higher
temperature compartment (10) respectively.
Inventors: |
Hallin; Anders; (Lidingo,
SE) |
Correspondence
Address: |
PEARNE & GORDON LLP
1801 EAST 9TH STREET
SUITE 1200
CLEVELAND
OH
44114-3108
US
|
Assignee: |
Dometic Sweden AB
Solna
SE
|
Family ID: |
27731068 |
Appl. No.: |
10/562186 |
Filed: |
June 30, 2004 |
PCT Filed: |
June 30, 2004 |
PCT NO: |
PCT/SE04/01059 |
371 Date: |
April 18, 2006 |
Current U.S.
Class: |
62/476 ;
62/349 |
Current CPC
Class: |
F25D 11/027 20130101;
F25B 39/026 20130101; F25D 2400/30 20130101; F25C 1/04 20130101;
F25C 2400/10 20130101; F25C 5/08 20130101; F25D 2321/1413
20130101 |
Class at
Publication: |
062/476 ;
062/349 |
International
Class: |
F25C 5/08 20060101
F25C005/08; F25B 15/00 20060101 F25B015/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 1, 2003 |
SE |
0301938-7 |
Claims
1. Absorption refrigerator (1) including a cabinet having outer
walls (2, 3, 4, 5, 6) and at least one door (7, 8) encasing a low
temperature storage compartment (9) and a higher temperature
storage compartment (10), said compartments being separated by a
partition wall (11), a device for ice fabrication, and an
absorption refrigerating system including an evaporator tube (20)
in which a refrigeration medium flows from an upstream end to a
downstream end of the evaporator tube, and which evaporator tube
comprises a first tube section (21) which is arranged to absorb
heat from the low temperature compartment, a second tube section
(22), which is arranged to absorb heat from the higher temperature
compartment and a third tube section (23) which is arranged to
absorb heat from the ice fabrication device, wherein the first,
second and third tube sections are connected in series and the
first tube section is arranged upstream of the second tube section,
characterized in that said third tube section (23) is arranged to
predominantly absorb heat from the ice fabrication device by heat
conduction and is arranged downstream of said first tube section
(21) and upstream of said second tube section (22) and in that the
ice fabrication device is exposed to air circulating in the low
temperature compartment or in the higher temperature compartment
(10), wherein means are provided for melting frost generated by
humidity in said low temperature compartment (9) or said higher
temperature compartment (10) respectively.
2. Absorption refrigerator according to claim 1, wherein the first
(21) and third (23) tube sections are arranged in the low
temperature compartment (9) and the second tube section (22) is
arranged in the higher temperature compartment (10).
3. Absorption refrigerator according to claim 1, wherein the third
tube section is arranged in a separate ice fabrication compartment
which communicates with the low temperature compartment or the
higher temperature compartment.
4. Absorption refrigerator according to claim 1, wherein the
upstream end of the third tube section (23) is connected directly
to the downstream end of the first tube section (21).
5. Absorption refrigerator according to claim 1, wherein the
upstream end of the second tube section (22) is connected to the
downstream end of the third tube section (23) through a passive gas
heat exchange tube section (28), which is arranged inside one of
the walls (2) of the cabinet.
6. Absorption refrigerator according to claim 1, wherein the first
tube section (21) includes two non-coaxial tube portions (21a), the
axis of which together define a general extension plane of the
first tube section and the third tube section (23) includes two
non-coaxial tube portions (23a), the axis of which together define
a general extension plane of the third tube section, whereby said
general extension plane of the first tube section is essentially
perpendicular to the general extension plane of the third tube
section.
7. Absorption refrigerator according to claim 6, wherein the
general extension plane of the first tube section (21) is
essentially vertical and generally parallel to the general
extension plane of the partition wall (11).
8. Absorption refrigerator according to claim 1, wherein the ice
fabrication device includes heating means for effecting partial
melting of the ice for facilitating harvesting of the ice.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to an absorption refrigerator
including; a cabinet having outer walls and at least one door
encasing a low temperature storage compartment and a higher
temperature storage compartment, said compartments being separated
by a partition wall, a device for ice fabrication, and an
absorption refrigerating system including an evaporator tube in
which a refrigeration medium flows from an upstream end to a
downstream end of the evaporator tube, and which evaporator tube
comprises a first tube section which is arranged to absorb heat
from the low temperature compartment, a second tube section, which
is arranged to absorb heat from the higher temperature compartment
and a third tube section which is arranged to absorb heat from the
ice fabrication device, wherein the first, second and third tube
sections are connected in series and the first tube section is
arranged upstream of the second tube section.
BACKGROUND OF THE INVENTION
[0002] Such absorption refrigerators are commonly used e.g. in
recreation vehicles, mobile homes or at homes were AC power supply
is not available at all times.
[0003] Normally, at the prior art refrigerators of this type, the
lower temperature compartment is a freezer, which at modern
absorption refrigerators normally is maintained at -18.degree. C.
The freezer also accommodates the device for fabrication of ice,
often referred to as the ice-maker. The ice maker may in it's
simplest form be an ice-cube container but it may also comprise
more sophisticated devices with means for automatic water supply
and ice harvesting means including mechanical members and
electrical heating elements. The higher temperature compartment is
normally maintained at around +5.degree. C. and could be referred
to as a refrigerator compartment.
[0004] The evaporator tube includes an upstream tube section, which
is dedicated for cooling the ice-maker. Downstream of this
ice-maker tube section and in direct connection to its downstream
end, an intermediate tube section is arranged for cooling the
freezer. Downstream of the freezer section, a downstream
refrigerator section of the evaporator tube is arranged for cooling
the higher temperature refrigerator compartment. At some
applications both the freezer and the ice-maker are cooled together
by one single evaporator tube section which is arranged upstream of
the refrigerator tube section.
[0005] The evaporator may be provided with various types of heat
conducting members for conducting heat from the items to be cooled,
i.e. the freezer and refrigerator compartments and the ice maker,
to the respective evaporator tube sections. As an example, the
ice-maker section of the evaporator may be provided with a heat
conducting plate, which is arranged to support the ice-cube
fabrication container and which conducts heat from the container to
the ice-maker section of the evaporator. The freezer and
refrigerator sections may be provided with flanges or baffles,
which conduct heat from the air in the freezer and refrigerator
compartments to the evaporator freezer and refrigerator section
respectively.
[0006] The evaporator tube sections and/or the respective heat
conducting members may further be provided with means for
defrosting. Such defrosting means may comprise heating means such
as an electrically heated film which is activated at regular
intervals or when the build up of frost has reached a certain
level. Upon activation of the heated film frost is melted.
[0007] The evaporator reaches its lowest evaporation temperature at
the upstream end. Downstream of the upstream end, the evaporation
temperature rises gradually when the cooling medium in the
evaporator tub absorbs heat from the ice-maker, freezer compartment
and refrigerator compartment.
[0008] A problem at this known type of absorption refrigerator is
that it is difficult to achieve a high enough cooling power of the
refrigeration system to maintain the freezer compartment at the low
temperature which is desired. As mentioned above, it is often
desired to keep the temperature in the freezer compartment as low
as approximately -18.degree. C. The total cooling power of the
absorption refrigerating apparatus is, among other factors, limited
by the heat transfer capacity of the evaporator, which in turn
depends on the total length of the evaporator tube. This length in
turn, is limited by the dimensions of the refrigerator cabinet and
by the fact that the evaporator tube needs to be designed with a
downward inclination over its entire length, from the upstream to
the downstream end.
[0009] At the upstream end of the evaporator tube, the evaporation
temperature of the refrigeration medium is normally approximately
-30.degree. C. During manufacturing of ice, i.e. during freezing of
water in the ice-maker, the ice-maker section of the evaporator
absorbs heat from the ice-maker. This heat absorption rises the
evaporation temperature of the refrigeration medium so that it, at
the entrance of the freezer section of the evaporator tube, is
approximately -24.degree. C. and at the exit approximately
-20.degree. C. Thus, during manufacturing of ice, the average
driving temperature difference between the desired freezer
temperature and the evaporation temperature of the refrigeration
medium would then be only about 2.degree. C. Such a small driving
temperature difference makes it impossible to bring down the
freezer to the desired temperature, especially when additional heat
enters into the freezer, e.g. due to opening of the freezer door,
placement of non-frozen items in the freezer or due to inward heat
transfer through the cabinet walls. Especially when utilizing some
kinds of automatic ice-makers, this problem is further increased.
During harvesting of the ice in such automatic ice-makers, the
ice-container is heated by an electrical heating element. Hereby,
the heat supplied to, and absorbed by the refrigeration medium in
the ice-maker section of the evaporator tube is further increased.
The cooling capacity available at the freezer evaporator section,
downstream of the ice-maker evaporator section is thus further
reduced during automatic harvesting of ice. In practice, it has
shown that the temperature in the freezer compartment rises between
6-9.degree. C. during operation of such automatic ice-makers. Also
at the type of absorption refrigerators, where the ice
manufacturing device and the freezer compartment are cooled by one
and the same evaporator tube section, the same negative influence
of the ice-maker on the cooling capacity in the freezer compartment
applies.
[0010] A further problem associated with ice-makers and
particularly with automatic ice-makers is the humidity which is
transferred from the ice-maker to the air in the refrigerator
during supply of water and during heating the ice prior to
harvesting. The humidity which is transferred to the air during
water supply and heating, does to a large extent contribute to the
formation of frost on the cool surfaces, i.e. the evaporators or
the heat conducting members arranged in the compartments or spaces
with which air coming in contact with the ice-maker communicates.
Thus, humidity released from the water in the ice-maker prior to
freezing of the water to ice and at harvesting heating is absorbed
by the air and circulated to the cool surfaces, where it forms
frost on these surfaces.
BRIEF SUMMARY OF THE INVENTION
[0011] It is therefore an object of the present invention to
provide an absorption refrigerator having a low temperature
compartment, a higher temperature compartment and an ice
manufacturing device, at which absorption refrigerator the total
cooling power of the refrigeration apparatus is more favorably
distributed between the two compartments and the ice-maker.
[0012] It is a further object to provide such an absorption
refrigerator, which facilitates to maintain the temperature in the
freezer compartment as low as desired, also when additional heat is
entered into the freezer compartment.
[0013] Another object is to provide such an absorption refrigerator
at which it is possible to use sophisticated ice-making devices
including heating elements without adversely affecting the cooling
capacity of the freezer compartment.
[0014] A still further object is to provide such an absorption
refrigerator at which the negative effects caused by the humidity
load generated by the ice-maker may be prevented or reduced by
utilizing the defrosting means associated with the freezer
evaporator or the refrigerator evaporator.
[0015] These and other objects are achieved with an absorption
refrigerator according to the first paragraph of this description
in which refrigerator the third tube section is arranged to
predominantly absorb heat from the ice fabrication device by heat
conduction and is arranged downstream of said first tube section
and upstream of said second tube section and in which the ice
fabrication device is exposed to air circulating in the low
temperature compartment, wherein means are provided for melting
frost generated by humidity in said low temperature compartment or
said higher temperature compartment respectively.
[0016] Through this arrangement of the different sections of the
evaporator tube, the first evaporator tube section, which absorbs
heat from the freezer compartment is arranged the most upstream of
the three sections. Hereby it is assured that that section of the
evaporator tube which exhibits the lowest evaporation temperature
cools the item, which needs to be maintained at the lowest
temperature, i.e. the freezer compartment. Thereby, it is also
assured that the greatest possible driving temperature difference
is used for maintaining the freezer compartment at the desired
temperature.
[0017] Since the ice-manufacturing device needs to be kept only at
about -10.degree. C. for sufficiently quick freezing of water to
ice, the increase of the evaporation temperature, which the
refrigeration medium undergoes during its absorption of heat in the
freezer tube section of the evaporator does not adversely affect
the capability of the ice-maker section to maintain the ice-maker
at a sufficiently low temperature.
[0018] The refrigerator compartment in turn, needs only to be kept
at about +5.degree. C. Therefore, the increase of the evaporation
temperature, which the refrigeration medium undergoes during its
passage through the ice-maker section of the evaporator does not
adversely affect the ability of the refrigeration section to
maintain the refrigeration compartment at the desired
temperature.
[0019] Since the ice fabrication device is exposed to air
circulating in the low or higher temperature compartment, it is
further guaranteed that the humidity load caused by the ice-maker
and absorbed by the air will be circulated to pass the freezer or
refrigerator evaporator or its heat conducting means such that the
frost resulting by this humidity may be defrosted by defrosting
means associated with the freezer or refrigerator evaporator. By
this means, no additional defrosting means needs to be provided for
taking care of frost caused by the excessive humidity load added by
the ice-maker.
[0020] Thus, by the arrangement of the different evaporator
sections according to the invention, it is assured that the total
cooling capacity generated by the refrigeration apparatus is
distributed by the evaporator to the items to be cooled in the most
effective manner at the same time as no additional defrosting means
needs to be arranged for eliminating frost generated by the
humidity load caused by the ice-maker.
[0021] Further objects and advantages of the invention are set out
in the depending claims.
DETAILED DESCRIPTION OF THE INVENTION
[0022] An exemplifying embodiment of the invention will now be
described with reference to the accompanying drawings in which:
[0023] FIG. 1 is a top elevation view, with parts of the walls
broken away, of a refrigerator cabinet according to the present
invention.
[0024] FIG. 2 is a perspective view from behind, with parts broken
away, of the refrigerator in FIG. 1.
[0025] In the figures a side-by-side absorption refrigerator 1 is
shown. The cabinet includes a rear wall 2, two side walls 3, 4, a
top-wall 5 and a bottom-wall 6. These outer walls 2-6, together
with two front doors 7, 8 enclose a low temperature storage
compartment 9 and a higher temperature storage compartment 10. The
outer walls 2-6 and the front doors 7, 8 all include an outer and
an inner shell between which heat insulating material, such as
polyurethane foam, is arranged. The two compartments 9, 10 are
hermetically sealed from each other by a vertical partition wall
11, which extends perpendicular to and from the rear wall 2,
between the rear wall 2 and the front of the cabinet 1, in such
away that the doors 7 and 8, when closed, sealingly rest against
the front of the partition wall 11. The freezer compartment 9 is
thus defined by the (in FIG. 1) left front door 7, the partition
wall 11, the side wall 3, and respective portions 2a, 5a, and 6a of
the rear wall, top wall and bottom wall. The higher temperature
compartment 10 is analogously defined by the (in FIG. 1) right
front door 8, the partition wall 11, the side wall 4, and
respective portions 2b, 5b, 6b of the rear wall, top wall and
bottom wall. The partition wall is placed approximately 1/3 of the
total width of the cabinet from one side-wall 3, so that the
width-relationship between the freezer compartment 9 and the
refrigerator compartment is approximately 1:2.
[0026] During operation, the temperature in the freezer compartment
is normally kept at about -18.degree. C., whereas the higher
temperature compartment normally is kept at about +5.degree. C. The
higher temperature compartment 10 could also be referred to as a
refrigerator compartment.
[0027] An absorption refrigerator system including a conventional
boiler, condenser, and absorber (neither of which is shown) is
arranged at the back of the cabinet, outside the rear wall 2. The
refrigerator system also includes an evaporator, generally
indicated by reference number 20. The evaporator 20 is formed of an
evaporator tube, which includes a first evaporator tube section 21
for cooling the freezer compartment and a second evaporator tube
section 22 for cooling the higher temperature compartment 10. The
first section 21 is arranged inside the freezer compartment 9 and
the second section 22 inside the higher temperature compartment
10.
[0028] The evaporator tube 20 also includes a third tube section 23
for cooling a device (not shown) for fabrication of ice,
hereinafter referred to as an ice-maker. The ice-maker may in its
simplest form be an ice-cube container, which is placed onto the
third evaporator section. It may however also be a more
sophisticated automatic device, including means for automatic water
supply, mechanical means for harvesting and crushing the ice as
well as electrical heating elements for partially melting the ice
prior to harvesting. Regardless of which type of ice maker is used,
it is arranged such that the predominant amount of heat, which is
removed from the water during the fabrication of ice, is conducted
to the third section of the evaporator.
[0029] The three evaporator sections 21, 22 and 23 are arranged in
series such that the evaporator tube is formed by one single
continuous tube, which includes the three sections, one after the
other. The first section 21 for cooling the freezer is arranged the
most upstream. The third section 23 for cooling the ice-maker is
arranged directly downstream of the first section. The second
section 22 for cooling the refrigerator is arranged downstream of
the third section 23.
[0030] At the upper, upstream end 24 of the evaporator 20, a first
conduit 25 supplies the coolant, such as liquid ammonium, from the
condenser to the evaporator 20. At the same upstream end 24, a
second conduit 26 supplies poor gas from the absorber.
[0031] The first evaporator tube section 21 is arranged immediately
downstream of the upstream end 24 of the evaporator. The first
evaporator section 21 comprises four generally straight tube
portions 21a, which are connected, one after the other through
three tube bends 21b. The straight tube portions 21a and the tube
bends 21b are arranged vertically, one over the other, generally in
the same vertical plane. At the downstream end of the lowest
straight tube portion 21a, a further tube bend 21c connects the
lowest straight tube portion with a further straight tube portion
21d, which extends generally perpendicular to the vertical plane
defined by the four straight tube portions 21a, in proximity to the
rear wall 2 of the cabinet. At the downstream end of this straight
tube portion 21d, the third section 23 of the evaporator is
connected to the first section through a tube bend 27. The third
section 23 is generally U-shaped and includes two generally
straight tube portions 23a connected with each other by a tube bend
23b. The U-shaped third section 23 is arranged generally
horizontal, whereby the two straight tube portions 23a and the tube
bend 23b are arranged in the same general horizontal plane.
[0032] At a lead-through 29, which is arranged through the inner
shell of the freezer rear wall portion 2a, at the downstream end of
the third evaporator section 23, the third evaporator section 23 is
connected to a passive evaporator section 28. The passive section
28 extends inside the rear wall 2 at a slight downward slope, past
the partition wall 11 This passive section 28 does not absorb heat
from any of the two compartments. However, it functions as a heat
exchanger absorbing heat from the mediums in the conduits 25 and
26. The passive tube section 28 is connected to the upstream end of
the second evaporator section 22 at a lead-through 30 in the
refrigerator portion 2b of the rear wall 2. The second evaporator
section 22 includes two generally straight tube portions 22a, which
are arranged, one over the other, generally in the same vertical
plane and connected by a tube bend 22b. At the down-stream end of
the second evaporator section 22, a lead-through 31 leads the
evaporator tube into the rear wall 2, where the evaporator tube,
together with the coolant supply conduit 25 is connected to a
co-axial gas heat exchanger tube 32. The co-axial tube 32 extends
in the rear wall 2, in a generally U-shaped manner and exits
through the outer shell of the rear wall. At the back of the
refrigerator cabinet, the co-axial tube is connected to the
absorber of the refrigerating apparatus (not shown).
[0033] During operation, when water is frozen to ice in the
ice-maker, the temperature of the refrigeration medium at the
upstream end 24 of the first evaporator section 21 is typically
maintained at approx. -30.degree. C. At the downstream end 27 of
the first evaporator section 21, the coolant temperature has
typically risen to approx. -24.degree. C. During the passage of the
coolant through the third evaporator section 23, the refrigeration
medium temperature is raised to approximately -20.degree. C. During
the passage of the coolant through the passive evaporator section
23, the temperature of the refrigeration medium increases due to
absorption of heat from the adjacent conduits 25, 26, whereby the
temperature at the upstream end of the second evaporator section 22
is about -16.degree. C. During passage through the second
evaporator section 22 the coolant temperature is typically raised
to approx. -12.degree. C. The different temperatures described
above vary over the working cycle of the ice-maker and depending on
external conditions as well as customer use. The exemplifying
values are given for illustrating a typical operation
situation.
[0034] For enhancing the heat transfer from the air in the freezer
compartment 9 and the refrigerator compartment 10 to the respective
evaporator sections 21 and 22, flanged baffle elements 34, 35 of a
heat conducting material are attached to the respective evaporator
section. The baffle elements 34, 35 exhibit a generally comb-shaped
transverse section and include a base and a plurality of flanges
having a vertical longitudinal direction.
[0035] The flanged baffle element 34 arranged in the freezer
compartment 9 is further provided with defrosting means (not
shown). These defrosting means comprises an electrical heater. The
electrical heater is activated at regular intervals for melting
frost, which has been formed on the baffle element. The heater may
also be activated when the formation of frost on the baffle element
34 has reached a certain thickness.
[0036] As can be seen from the figures, the ice-maker and the
baffle element 34 are arranged within the same space, such that air
which is exposed to the ice-maker during circulation will pass the
baffle element 34. Since this baffle element 34 constitutes the
coolest area within the delimited space in which this air may
circulate, any humidity absorbed by this air from the ice-maker
will form on this baffle element 34. Thereby, all frost caused by
the humidity generated by the ice-maker will be defrosted during
regular defrosting of the freezer compartment 9.
[0037] In the embodiment shown, the baffle element 34, the freezer
evaporator 21, the ice-maker and the ice-maker section 23 of the
evaporator are all arranged within the same compartment. This must
however not be the case as long as the air is able to circulate
between the ice-maker and the freezer evaporator or refrigerator
evaporator or the heat conducting element associated with the
freezer evaporator or refrigerator evaporator respectively,
whichever is provided with means for defrosting frost which is
caused by humidity present in the low temperature compartment or
the higher temperature compartment.
[0038] In one not shown embodiment for instance, the freezer
evaporator tube section and the ice-maker evaporator tube section
are arranged embedded in the rear wall of the cabinet. The freezer
tube section of the evaporator is connected to a baffle element
which is arranged in a first space and which comprises defrosting
means, while the ice-maker is arranged in the freezer compartment
which is formed in a second remotely arranged space. A heat
transferring plate or a heat pipe is arranged between the ice-maker
and the ice-maker evaporator tube section. Air ducts are further
provided between the first and second spaces such that air may
circulate between these two spaces. By such an arrangement it is
possible to arrange the freezer compartment at distance from the
freezer evaporator tube section, which enables a greater
flexibility concerning evaporator tube design and the positioning
of the low temperature compartment.
[0039] By the arrangement of the first, second and third evaporator
section 21, 22 and 23 described above, it is accomplished that,
during operation of the refrigerating system, the freezer
compartment is always cooled by the coolest part of the evaporator,
which part also has the lowest evaporation temperature of the
refrigerant medium. Hereby, it is assured that the driving
temperature difference, between the air in the freezer and the
freezer section of the evaporator, for cooling the freezer
compartment always is the greatest possible. This in turn
contributes to making it possible to, at all times, maintain the
air in the freezer compartment at temperatures as low as
-18.degree. C., which is often desired at modern absorption
refrigerators. Further more the arrangement ensures that the
humidity load generated by the ice-maker is taken care of by the
defrosting means arranged for melting frost generated by humidity
present in the air in the low temperature compartment.
[0040] The invention further accomplishes that heat added from the
ice-maker, during cooling of the water and during heating of the
ice for facilitating harvesting, does not significantly affect the
evaporation temperature of the refrigeration medium in the freezer
section of the evaporator. Studies have shown that the evaporation
temperature of the freezer section of the evaporator rises only
about 2.degree. C. during operation of the ice-maker at a
refrigerator according to the invention. The operation of the
ice-maker thereby, does not force the refrigeration apparatus to
compensate for heat added from the manufacturing or harvesting of
ice. The invention thus provides an absorption refrigerator, at
which the temperature of the freezer compartment may be maintained
at the desired level regardless of the operation of the
ice-maker.
[0041] Above, an exemplifying embodiment of the invention has been
described. The invention may however be modified within the scope
of the appending claims. Instead of being arranged in the lower
temperature freezer compartment, the third section of the
evaporator may be arranged in the higher temperature refrigerator
compartment. In such case the third section is arranged downstream
of the passive evaporator section and upstream of the second
evaporator section, whereby the third section of the evaporator or
its heat transferring means is provided with means for melting
frost formed on said evaporator section or said heat transferring
means. The third section of the evaporator may also be arranged in
a separate ice-maker compartment which communicates with the low
temperature compartment or the higher temperature compartment,
depending of which of these compartments communicates with
defrosting means.
[0042] The first, second and third evaporator sections may have
other tube configurations than the ones described above. The may
for instance be formed by fewer or more interconnected straight
tube portions or they may be formed by tube sections which are
curved along their whole lengths.
[0043] In the above-illustrated embodiment, the partition wall
hermetically seals the freezer and the higher temperature
compartments from each other. Small deviations from this principle
may be allowed, as long as no significant heat transfer is effected
between the two compartments
* * * * *