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(11) | EP 2 538 156 A2 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Multi-evaporator refrigerator |
| (57) A refrigeration system for a refrigerator having a freezer compartment (13), a fresh
food compartment (8), an icemaker (50) in the fresh food compartment (8) includes
distinct freezer (96), fresh food (130) and icemaker evaporators (115)and associated
valving operating in conjunction with a common compressor (65) and condenser (75)
in order to effectively regulate temperatures in specified zones of the refrigerator
throughout various operational modes including at least a freezer cooling mode, a
fresh food cooling mode and an ice harvesting mode. The icemaker (115) can be serially
linked with the fresh food evaporator (130) during cooling of the fresh food compartment
(8), while being also being selectively isolated for the ice harvesting mode.
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BACKGROUND OF THE INVENTION
Field of the Invention
[0001] The present invention pertains to the art of refrigerators and, more particularly, to the operational control of a refrigerator employing multiple evaporators.
Description of the Related Art
[0002] In general, a refrigerator includes a freezer compartment for maintaining foods at or below freezing temperatures, and a fresh food compartment for maintaining foods in a temperature zone between ambient and freezing temperatures. A typical refrigerator includes a refrigeration system having a compressor, a condenser, a condenser fan, an evaporator and an evaporator fan. In operation, temperature sensors are used to measure temperatures within the fresh food and freezer compartments. When the temperature of one of the compartments deviates from a predetermined temperature, the refrigeration system is activated to return the temperature to at or below the predetermined temperature. As part of the overall refrigeration system, a damper is typically provided between the freezer and fresh food compartments, wherein operation of the damper controls the flow of cooling air from the freezer compartment to the fresh food compartment. Therefore, a common refrigeration system with a single evaporator is typically employed, along with various air flow fans, to create a flow of cold air used to cool each of the fresh food and freezer compartments, and even possibly onto an icemaker provided in the refrigerator.
[0003] Certainly, it is possible to establish distinct refrigeration systems for each of the fresh food and freezer compartments. Although presenting some advantages in enabling the isolated control of the compartments, such an arrangement would be considerably more expensive. Still, there is seen to be a need in the art for a refrigeration system which can establish separated air zones and operate in various control modes in order establish a highly efficient and effective temperature supply and demand scheme.
SUMMARY OF THE INVENTION
[0004] The present invention is directed to a refrigerator incorporating a freezer compartment, a fresh food compartment, an icemaker and a refrigeration system including multiple evaporators and associated valving which operate in conjunction with a common compressor and condenser in order to effectively regulate temperatures in specified zones of the refrigerator throughout various operational modes. More particularly, the refrigerator can be operated in at least a freezer cooling mode, a fresh food cooling mode and an ice harvesting mode. The icemaker is located in the fresh food compartment and can be selectively linked to the cooling of the fresh food compartment, while being also being selectively isolated for at least the ice harvesting mode.
[0005] More specifically, each of the freezer, fresh food and icemaker is provided with a dedicated evaporator such that, during the freezer cooling mode, refrigerant flows from the compressor, to the condenser, through the freezer evaporator and back to the compressor. During fresh food compartment cooling, the refrigerant bypasses the freezer evaporator and instead flows from the condenser to the fresh food evaporator, preferably through the icemaker evaporator, prior to being directed back to the compressor. During an ice harvest event, a gaseous flow from the compressor is routed directly to the evaporator of the icemaker to melt ice at an ice/icemaker evaporator interface in aiding in the release of the ice from an ice mold. The arrangement of the components and the strategic locating of the valving establishes the distinct, isolated flow patterns for the various modes of operation.
[0006] Additional objects, features and advantages of the present invention will become more readily apparent from the following detailed description of preferred embodiments when taken in conjunction with the drawings wherein like reference numerals refer to corresponding parts in the several views.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] Figure 2 is a schematic illustration of a refrigeration system for the refrigerator of Figure 1;
[0009] Figure 3 is a schematic illustration of the refrigeration system of Figure 2 in a freezer cooling mode;
[0010] Figure 4 is schematic illustration of the refrigeration system of Figure 2 in a fresh food cooling mode; and
[0011] Figure 5 is a schematic illustration of the refrigeration system of Figure 2 in an ice harvesting mode.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0012] With initial reference to Figure 1, a refrigerator 2 includes an outer shell or cabinet 4 within which is positioned a liner 6 that defines a fresh food compartment 8. In a manner known in the art, fresh food compartment 8 can be accessed by the selective opening of a fresh food door 10. In a similar manner, a freezer door 12 can be opened to access a freezer compartment 13. In the embodiment shown, freezer door 12 includes a dispenser 14 that enables a consumer to retrieve ice and/or fresh water without accessing fresh food or freezer compartments 8 and 13. For the sake of completeness, door 10 of refrigerator 2 is shown to include a dairy compartment 15 and various vertically adjustable shelving units, one of which is indicated at 16.
[0013] In a manner known in the art, fresh food compartment 8 is provided with a plurality of vertically, height adjustable shelves 20-22 supported by a pair of shelf support rails, one of which is indicated at 25. At a lowermost portion of fresh food compartment 8 is illustrated various vertically spaced bins 28-30. At this point, it should be recognized that the above described refrigerator structure is known in the art and presented only for the sake of completeness. The present invention is not limited for use with a side-by-side style refrigerator shown, but may be utilized with other known refrigerator styles including top-mount, bottom-mount, or French door style refrigerators. In any case, as also shown in Figure 1, refrigerator 2 also includes an icemaker, generally indicated at 50. In the preferred embodiment shown, icemaker 50 is located within fresh food compartment 8. With this in mind, the invention is particularly directed to the refrigeration system employed in connection with fresh food compartment 8, freezer compartment 13 and icemaker 50, and particularly the manner in which the refrigeration system is structured and controlled through a controller 55 to operate in various distinct modes as will be detailed fully below.
[0014] Details of a refrigeration system 60 constructed in accordance with a preferred embodiment of the invention will now be set forth with reference to Figure 2. As shown, refrigeration system 60 includes a compressor 65 having an associated mount 67. Although not represented in this figure, compressor 65 is preferably mounted in a lower machine compartment of cabinet 4, such as below freezer compartment 13. Compressor 65 is connected at an inlet (not labeled) to an intake or suction line 70 and has a main outlet line 72. Interposed within main outlet line 72 is a first, three-way switching valve 74. Downstream of three-way switching valve 74, main outlet line 72 leads to a condenser 75 having an associated fan 77. Leading from condenser 75 is a liquid refrigerant line 85 which represents an input into a three-way switching valve 90. Stemming from three-way switching valve 90 is a first supply line 93 that leads, through a capillary tube or other expansion device (not labeled), to a freezer evaporator 96 having an associated fan 100. From freezer evaporator 96 extends a first return line 103 which is connected to suction line 70. Prior to reaching suction line 70, first return line 103 is provided with a one-way check valve 105. As illustrated, one-way check valve 105 only allows fluid to flow in one direction within first return line 103 from freezer evaporator 96 to suction line 70 and back to compressor 65.
[0015] Also stemming from three-way switching valve 90 is a second supply line 110 which leads, through another expansion device (not labeled), to an icemaker evaporator 115. Subsequent to icemaker evaporator 115 is a second two-way switching valve 118. A first outlet associated with two-way switching valve 118 defines a third supply line 124 which leads to a fresh food evaporator 130 having an associated fan 134. Leading from fresh food evaporator 130 is a second return line 140 which is fluid communication with suction line 70 and leads back to compressor 65. A second outlet associated with three-way switching valve 118 is defined by a third return line 145 which is also in fluid communication with suction line 70 and leads back to compressor 65. Finally, first three-way switching valve 74 is also connected to a bypass line 150 which merges with second supply line 110 so as to be in fluid communication with icemaker evaporator 115.
[0016] With the above arrangement, refrigeration system 60 can effectively and efficiently operate in numerous modes. More specifically, Figure 3 illustrates the flow path of refrigerant when refrigeration system 60 is in a freezer cooling mode. In this mode, compressor 65 feeds refrigerant flow through three-way switching valve 74, condenser 75 and three-way switching valve 90 to freezer evaporator 96. With the operation of fan 100, freezer compartment 13 is effectively cooled, with the refrigerant exiting freezer evaporator 96 being directed back to suction line 70 and compressor 65 through first return line 103 and check valve 105.
[0017] When cooling of fresh food compartment 8 is indicated, based on the signal from at least one temperature sensor (not shown) and a user-selected cooling level for fresh food compartment 8, refrigeration system 60 is operated in a fresh food cooling mode as represented in Figure 4. As depicted, compressor 65 feeds refrigerant flow through main outlet line 72, three-way switching valve 74 and condenser 75 to three-way switching valve 90 in a manner directly corresponding to freezer cooling mode discussed above. However, based on the repositioning of three-way switching valve 90, the refrigerant is redirected into second supply line 110 so as to flow into icemaker evaporator 115 prior to reaching three-way switching valve 118. As icemaker evaporator 115 also receives coolant, the fresh food cooling mode of this preferred embodiment could actually be referred to as a fresh food cooling/icemaking mode. However, for the sake of simplicity and to disclose the invention in a more generic fashion, continued reference to a fresh food cooling mode will be made. In any case, given the desire to further cool fresh food compartment 8, three-way switching valve 118 is positioned such that the refrigerant flows from icemaker evaporator 118 into third supply line 124 and fresh food evaporator 130. At the same time, fan 134 is operated in order to direct a flow of air across fresh food evaporator 130 and into fresh food compartment 8. Thereafter, the refrigerant continues to flow into second return line 140 which leads back to suction line 70 and compressor 65 in a recirculating fashion. Due the presence of check valve 105, refrigerant flowing through suction line 70 is prevented from back-flowing into first return line 103 toward freezer evaporator 96 which, at this point, would be at a low pressure.
[0018] As clearly illustrated in these figures, it is preferred in accordance with the present invention to include icemaker 50 in fresh food compartment 8 and, correspondingly, icemaker evaporator 115 within fresh food compartment 8. This arrangement represents a preferred embodiment which produces clear ice in refrigerator 2 such that it is desired to maintain a supply of water in icemaker 50 except at an ice making mold or member(s) (not shown). Since the particular manner in which the ice is formed does not form part of the present invention, it will not be discussed in detail here. Instead, any ice making arrangement known in the art can be utilized in accordance with the overall invention, although clear ice making is preferred. However, it is an aspect of the present invention to establish an ice harvesting mode for icemaker 50. To this end, Figure 5 illustrates an arrangement wherein refrigeration system 60 is operated such that refrigerant leading from compressor 65 does not reach condenser 75 but instead hot gases are diverted at two-way switching valve 74 into a bypass line 150, which leads directly into icemaker evaporator 115. In this mode, three-way switching valve 90 is closed and three-way switching valve 118 is positioned by controller 55 to redirect the flow from icemaker evaporator 115 into third return line 145. As indicated above, third return line 145 is in direct communication with suction line 70 so as to return refrigerant to compressor 65. In a manner directly corresponding to that discussed above with respect to the fresh food cooling mode of Figure 3, check valve 105 also operates in the ice harvesting mode to prevent back-flow into first return line 103 and freezer evaporator 96. In a similar manner, three-way switching valve 118 also blocks flow to fresh food evaporator 130. With this arrangement, hot gases from compressor 65 are delivered into icemaker evaporator 115 to melt ice at an ice/icemaker evaporator interface in connection with releasing the ice from an ice mold (not shown) of icemaker 50.
[0019] Based on the above, it should be readily apparent that refrigerator system 60 includes a common compressor 65 and common condenser 75 and, through the use of strategically placed valving, can selectively regulate flow to one or more of freezer evaporator 96, icemaker evaporator 115 and fresh food evaporator 130 in order to selectively establish at least freezer cooling, fresh food cooling and ice harvesting modes of operation. By providing control algorithms to establish the different modes of operation, the refrigeration system 60 effectively handles any surplus of cooling capacity and at least compressor 65 can be operated with a lower temperature differential, thereby enhancing the overall efficiency of refrigerator 2, while rapidly making ample amounts of ice in an energy efficient manner. In addition, the multi-evaporator arrangement establishes more effective temperature control for fresh food and freezer compartments 8 and 13 through the use of separated air zones, while also enhancing odor and humidity control, minimizing temperature swings and reducing defrosting based on a lower humidity load in freezer compartment 13.
[0020] Although the most preferred form of the fresh food cooling mode has refrigerant flowing serially through the icemaker evaporator and then the fresh food evaporator, additional valving could be employed to selectively direct refrigerant from the three-way switching valve into the fresh food evaporator for fresh food cooling, while also enabling a flow to the icemaker evaporator when the icemaker further demands cooling to produce ice. In another variation, the icemaker evaporator could follow the fresh food evaporator, instead of vise-versa.
a cabinet (4) within which is defined a fresh food compartment (8) and a freezer compartment (13);
an icemaker (50) mounted in the fresh food compartment (8);
a refrigeration system (60) including:
a compressor (65) connected to an intake line (70), said compressor being adapted to establish a flow of refrigerant through the refrigeration system (60);
a condenser (75) in fluid communication with the compressor (65) through an outlet line (72);
a freezer evaporator (96) for cooling the freezer compartment (13), said freezer evaporator being adapted to be placed in fluid communication with the condenser (75) through a first supply line (93) and to the intake line (70) through a first return line (103);
a fresh food evaporator (130) for cooling the fresh food compartment (8), said fresh food evaporator being adapted to be placed in fluid communication with the condenser (75) through a second supply line (110) and to the intake line (70) through a second return line (140);
an icemaker evaporator (115) provided in the fresh food compartment (8) for cooling the icemaker (50), said icemaker evaporator (115) also being adapted to be placed in fluid communication with the condenser (75) through the second supply line (110) and to the intake line (70) through a third return line (145); and
a bypass line (150) interconnecting the outlet line (72) and the icemaker evaporator (115); and
a controller (55) operatively coupled to the refrigeration system (60) for selectively operating the refrigeration system in a freezer cooling mode, a fresh food cooling mode and an ice harvesting mode wherein: in the freezer cooling mode, refrigerant is directed from the compressor (65) and through the condenser (75) to the freezer evaporator (96) before returning to the compressor (65) through the first return line (103) and the intake line (70), while bypassing the fresh food evaporator (130) and the icemaker evaporator (115); in the fresh food cooling mode, refrigerant is directed from the compressor (65) and through the condenser (75) to the fresh food evaporator (130) before returning to the compressor (65) through the second return line (140) and the intake line (70), while bypassing the freezer evaporator (96); and in the ice harvesting mode, hot gas from the compressor (65) is directed to the icemaker evaporator (115) through the bypass line (150) before returning to the compressor (65) through the third return line (145) and the intake line (70), while bypassing the condenser (75), the freezer evaporator (96) and the fresh food evaporator (130).
when in the freezer cooling mode, refrigerant is directed from a compressor (65) and through a condenser (75) to a freezer evaporator (96) before returning through a first return line (103) to an intake line (70) of the compressor (65), while bypassing a fresh food evaporator (130) and an icemaker evaporator (115);
when in the fresh food cooling mode, refrigerant is directed from the compressor (65) and through the condenser (75) to the fresh food evaporator (130) before returning to the compressor through a second return line (140) and the intake line (70), while bypassing the freezer evaporator (96); and
when in the ice harvesting mode, hot gas from the compressor (65) is directed to the icemaker evaporator (115) through a bypass line (150), extending from between the compressor (65) and condenser (75) to the icemaker evaporator (115), before returning to the compressor (65) through a third return line (145) and the intake line (70), while bypassing the condenser (65), the freezer evaporator (96) and the fresh food evaporator (130).
when in each of the freezer cooling and fresh food cooling modes, operating a first valve (74), located between the compressor (65) and the condenser (75), to direct refrigerant flow from the compressor to the condenser; and
controlling a second valve (90), located between the condenser (75) and each of the freezer and fresh food evaporators (96, 130), to be in: a first operational position permitting flow between the condenser (75) and the freezer evaporator (96) through a first supply line (93), while preventing flow to each of the fresh food and icemaker evaporators (130, 115), in the freezer cooling mode; a second operational position permitting flow between the condenser (75) and the fresh food evaporator (130) through a second supply line (110), while preventing flow to the freezer evaporator (96), in the fresh food cooling mode; and a third, closed position to prevent flow through each of the first and second supply (93, 110) lines when the refrigerator is in neither of the freezer nor fresh food cooling modes.