Absorption refrigerator

Abstract

An 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 essentially sealed from each other and separated by a partition wall (11), which partition wall is arranged inside the cabinet and generally perpendicular to a first wall (2) of said outer walls. The refrigerator further comprises an absorption refrigerating system including an evaporator tube (20), having a first section (21) for absorbing heat from the low temperature compartment and a second section (22) for absorbing heat from the higher temperature compartment, said second section being arranged downstream said first section. In order to reduce heat transfer into the cabinet through the outer walls, a major part of the first section is arranged generally in parallel with said partition wall.

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 essentially sealed from each other and separated by a partition wall, which partition wall is arranged inside the cabinet and generally perpendicular to a first wall of said outer walls, and an absorption refrigerating system including an evaporator tube having a first evaporator tube section for cooling the low temperature compartment and a second evaporator tube section for cooling the higher temperature compartment, said second evaporator tube section being arranged downstream said first evaporator tube section. BACKGROUND OF THE INVENTION [0002] Absorption refrigerators have been commonly used in e.g. recreation vehicles and mobile homes for a long time. More recently, so called side-by-side absorption refrigerators...

AI Technical Summary

Benefits of technology

[0006] It is an objective of the present invention to provide an absorption refrigerator at which the cooling capacity of the refrigerating system is more efficiently used for keeping the items stored in the cabinet at the desired temperature.

[0007] It is a further object to provide an absorption refrigerator at which the heat transfer through the surrounding walls into the cabinet is reduced.

[0008] A further object is to provide an absorption refrigerator at which the heat transfer particularly into the freezer compartment is reduced.

[0009] A still further object is to provide an absorption refrigerator at which the time needed for lowering the freezer temperature to the desired temperature at start up is reduced.

[0011] By such an arrangement of that section of the evaporator, which absorbs heat from the freezer compartment, it is assured that at least the major part of this section is arranged at a distance from the rear walls. Thereby, the major part of the freezer evaporator predominantly absorbs heat from the air in the freezer compartment and no superfluous cooling of the outer walls is caused. The outer walls thus remain at a higher temperature, whereby heat transfer from the surrounding atmosphere through the outer walls is reduced. The reduction of heat absorbed from the outer walls also reduces the time for lowering the freezer temperature at start-up. Also when the freezer section of the evaporator is arranged in or in the proximity of the dividing wall, the pull-down time is reduced since the heat contained in the dividing wall at start-up is considerably less than that in the outer walls, due to thinner insulation. Further more, such placement of the freezer section contributes to lowering the temperature in the higher temperature compartment, on the other side of the dividing wall.

[0012] Further objects and advantages of the invention are set out in the depending claims. According to one embodiment, the partition wall is arranged as a vertical wall extending between the outer rear wall and the front door or doors. Thereby, the invention is advantageously applied to a modern side-by-side refrigerator. The second section of the evaporator, which cools the higher temperature compartment, may be arranged in parallel with the rear wall. This may be advantageous for space saving or tube bending purposes and such placement of the second section of the evaporator does not to the same extent contribute to the heat transfer into the higher temperature compartment, since this evaporator section is kept at a higher temperature. The freezer section of the evaporator may be arranged in parallel to, and in proximity to the partition wall. Hereby, a gap may be arranged between the evaporator freezer section and the partition wall. Such a gap allows for air to freely circulate around the freezer evaporator section, which enhances heat transfer from the air in the freezer compartment to the evaporator. Further more, such a gap prevents that the freezer evaporator absorbs heat from the partition wall, whereby the system is more efficiently used for cooling the air and items stored in the freezer compartment. This also contributes to reduce the pull-down time even further. The freezer section of the evaporator may also be arranged entirely or partly in the dividing wall, whereby the space requirement for the evaporator inside the freezer cabinet is reduced. In order to further enhance the heat transfer from the air to the evaporator, at least a portion of the evaporator may be provided with heat transferring flanges.

Problems solved by technology

A problem with this type of absorption refrigerator cabinets is a considerable heat transfer through the rear wall from the outside of the cabinet to the inside.

Heat transfer into the refrigerator cabinet is particularly disadvantageous at absorption refrigerators used in mobile applications.

At absorption refrigerators, the physical dimensions of the refrigeration system limit the maximum cooling capacity.

This makes it difficult to keep the respective compartments at the desired temperature.

This problem is particularly severe for the freezer compartment, for which, at modern mobile refrigerators, it is desired to keep the temperature as low as −18° C. Any heat which is added into the cabinet is therefore most undesirable and often causes the temperature in the freezer to raise above the desired value.

This in turn deteriorates the quality of foodstuff stored in the freezer or reduces the maximum possible storage time.

A further problem with the above-described known refrigerator is that the time required for lowering the freezer temperature from the starting temperature to the desired freezer temperature at start up of the system (so called “pull-down”) is relatively long.

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