Refrigerator With Humidity-Optimized Storage Compartment

Abstract

A refrigeration appliance includes a coolant circuit in which a speed-controlled compressor, an adjustable restrictor and a forced-air cooled first evaporator are connected in series. An evaporator chamber receives the first evaporator, a first storage compartment communicates with the evaporator chamber and a second storage compartment communicates with the evaporator chamber. A control unit or controller is configured to distribute cold air from the evaporator between the first and second storage compartments according to desired temperatures which can be adjusted differently for the first and the second storage compartments.

Claims

1.-15. (canceled)

16. A refrigeration appliance, comprising: a speed-controlled compressor, an adjustable restrictor and a forced-air cooled first evaporator connected in series in a coolant circuit; an evaporator chamber receiving said first evaporator; a first storage compartment communicating with said evaporator chamber; a second storage compartment communicating with said evaporator chamber; and a control unit configured to distribute cold air from said evaporator between said first and second storage compartments according to desired temperatures being adjustable differently for said first and second storage compartments.

17. The refrigeration appliance according to claim 16, wherein said control unit is configured to limit a temperature difference to a maximum of 7 C. between an evaporation temperature in said first evaporator and a desired temperature of said second storage compartment.

18. The refrigeration appliance according to claim 16, wherein said control unit is configured to maintain a temperature difference of a minimum of 20 C. between an evaporation temperature in said first evaporator and a desired temperature of said second storage compartment.

19. The refrigeration appliance according to claim 16, which further comprises at least one passage between said evaporator chamber and said storage compartments, and a flap disposed at said at least one passage, said flap being adjustable by said control unit.

20. The refrigeration appliance according to claim 19, wherein: said flap has two stable positions; in one of said positions said passage between said evaporator chamber and said first storage compartment is open and said passage between said evaporator chamber and said second storage compartment is closed; and in another of said positions said passage between said evaporator chamber and said first storage compartment is closed and said passage between said evaporator chamber and said second storage compartment is open.

21. The refrigeration appliance according to claim 19, which further comprises: a first fan accommodated in said passage between said evaporator chamber and said first storage compartment; and a second fan accommodated in said passage between said evaporator chamber and said second storage compartment; said fans having throughputs being controllable by said control unit.

22. The refrigeration appliance according to claim 21, wherein said fans do not operate simultaneously.

23. The refrigeration appliance according to claim 16, which further comprises a second evaporator disposed in said coolant circuit downstream of said first evaporator, and a restrictor disposed between said first and second evaporators.

24. The refrigeration appliance according to claim 23, wherein said restrictor is an adjustable restrictor and another restrictor is connected upstream of said first evaporator.

25. The refrigeration appliance according to claim 23, which further comprises a third storage compartment, said second evaporator cooling at least said third storage compartment.

26. The refrigeration appliance according to claim 25, wherein said evaporator chamber is separate from said third storage compartment, and said second evaporator is forced-air cooled and is accommodated in said evaporator chamber.

27. The refrigeration appliance according to claim 26, which further comprises: a fourth storage compartment; said control unit being configured to use desired temperatures of said third and fourth storage compartments to control: an exchange of air between said evaporator chamber and said third storage compartment, and an exchange of air between said evaporator chamber and said fourth storage compartment.

28. The refrigeration appliance according to claim 27, wherein said second and fourth storage compartments are identical.

29. The refrigeration appliance according to claim 27, which further comprises an adjustable partition provided between said second and fourth storage compartments.

30. The refrigeration appliance according to claim 16, wherein said control unit is configured to continuously operate said speed-controlled compressor.

Description

[0025] Further features and advantages of the invention result from the following description of exemplary embodiments with reference to the accompanying figures. In the drawings:

[0026] FIG. 1-4 show block diagrams of refrigeration appliances according to different embodiments of the invention.

[0027] FIG. 1 shows a block diagram of a refrigeration appliance according to a first embodiment of the invention. The refrigeration appliance is a combination appliance having warm, intermediate and cold compartments 1, 2 and 3, respectively, typically a standard refrigeration compartment, a chill compartment and a freezer compartment, which are cooled by a compression refrigeration machine 4. The compression refrigeration machine 4 comprises a speed-controlled compressor 5 and, in turn, a coolant line 8 running from a pressure connection 6 of the compressor 5 to its intake connection 7, a condenser 9, a first restrictor 10, a first evaporator 11, a second restrictor 12 and a second evaporator 13.

[0028] The evaporators 11, 13 are accommodated in evaporator chambers 14, 15. The evaporator chamber 14 communicates via feed lines 16, 17 and return lines 18, 19 with the standard refrigeration compartment 1 and the chill compartment 2. The two evaporator chambers 14, 15 each contain a fan 20, 21 for driving the exchange of air between the evaporator chambers 14, 15 and the connected storage compartments 1, 2, 3.

[0029] FIG. 1 shows a flap 22 at the connection point of the feed lines 16, 17 with the evaporator chamber 14; the flap 22 can be swiveled between two positions, in which it blocks one of the feed lines 16, 17 and unblocks the other one respectively. It is shown in an intermediate position, in which the two feed lines 16, 17 are open. Alternatively the flap could be arranged at the connection point between the return lines 18, 19 and the evaporator chamber 14 in order to block one of the return lines 18, 19 and unblock the other one respectively. According to further alternatives, two flaps could also be distributed among the feed lines 16, 17 or the return lines 18, 19, or the fan 20 could be replaced by two fans in the feed lines 16, 17 or the return lines 18, 19, which can be operated at speeds that are regulated independently of each other or, preferably, at different times respectively in order to control the exchanges of air between the evaporator chamber 14 and the compartments 1, 2 independently of each other respectively.

[0030] A temperature sensor (not shown in FIG. 1 for the sake of clarity) is provided on each storage compartment 1, 2, 3. The temperature sensors are connected to an electronic control unit 23. A desired temperature can be adjusted at the control unit 23 for each storage compartment 1, 2, 3. Using the measured values and the desired temperatures supplied by the temperature sensors, the control unit 23 controls the speed of the compressor 5, the position of the flap 22 as well as the degree of opening of at least one of the two restrictors 10, 12 or of both. If one of the two restrictors cannot be controlled, then this is preferably the first restrictor 10.

[0031] To cool standard refrigeration compartment 1 and chill compartment 2 simultaneously, the flow of cold air from the evaporator 11 must be distributed between the two compartments. This can be done by the flap 22 being in an intermediate position, in which it does not completely block any of the feed lines 16 and 17 and cold air flows from the evaporator 11 simultaneously to the two compartments 1, 2. However, this leads to mixing of the air masses, with different moisture levels in the compartments 1 and 2, in the evaporator chamber 14 and therefore ultimately to an outflow of humidity from the chill compartment 2. To minimize this it is preferred, in order to cool standard refrigeration compartment 1 and chill compartment 2, to switch the flap 22 between its two stop positions at regular intervals, so thatirrespective of the times at which the flap moves from one stop position into the otherof the two feed lines 16 and 17, one is always blocked.

[0032] Each switchover of the flap 22 leads to a quantity of air, which corresponds to the volume of the evaporator chamber 14, being exchanged between the compartments 1 and 2. To keep the effects of this exchange to a minimum, the period between two switchovers of the flap 22 should be greater than the quotient of volumes of the evaporator chamber 14 and throughput of the fan 20, preferably greater than ten times this quotient.

[0033] If the temperature of the chill compartment 2, but not that of the standard refrigeration compartments 1, is above the desired temperature, the control unit 23 extends the period, which the flap 22 spends in the position blocking the feed line 16, and reduces the time spent in the position blocking the feed line 17 accordingly, in order to intensify the exchange of air between the evaporator chamber 14 and the chill compartment 2. This can suffice as a correction measure if the cooling output of the evaporator 11 is sufficient for the two compartments 1, 2. If it is not, sooner or later both compartments 1, 2 are heated above their desired temperature. If this occurs, but the freezer compartment 3 does not exceed its desired temperature, then the restrictors 10, 12 or at least the restrictor 12 are triggered to reduce the pressure differential between the evaporators 11, 13 and thereby lower the evaporation temperature in the evaporator 11. If this leads to the desired temperature in the freezer compartment 3 being exceeded, then the speed of the compressor 5 has to be increased.

[0034] In this way, over the course of time, a temperature is established at the evaporator 11, which is just sufficiently below that of the chill compartment 2 to keep it at the desired temperature. Moisture from the air in the chill compartment 2 is only deposited on the evaporator 11 if the humidity in the chill compartment 2 is so high and the temperature difference from the evaporator 11 is so great that the air exceeds the dew point on cooling at the evaporator 11. The quantity of water vapor saturated in air reduces with a temperature decrease by 5 C. by about one third. Only if the relative humidity in the chill compartment 2 exceeds 67% can cooling by 5 C. at the evaporator 11 consequently lead to condensation, and it is not possible to fall below a relative humidity of 67%.

[0035] The temperature difference between the standard refrigeration compartment 1 and the evaporator 11 is significantly greater; the air in the standard refrigeration compartment 1 is correspondingly dried to a much greater degree by the evaporator 11. The user can take account of this by using the chill compartment 2 for chilled goods that are susceptible to drying out, and, in contrast, by using the standard refrigeration compartment 1 for chilled goods that are not sensitive to dry storage conditions or for packaged chilled goods.

[0036] In the embodiment of FIG. 1 the evaporator 13 cools only the freezer compartment 3.

[0037] A crisper 24 is also provided in the embodiment of FIG. 2. The desired temperature thereof can be adjusted to a level similar to that of the chill compartment 2. The evaporator chamber 15 communicates with the freezer compartment 3 and the crisper 24 via feed and return lines 25, 26, 27, 28 in a manner similar to the evaporator chamber 14 with the standard refrigeration compartment 1 and the chill compartment 2. FIG. 2 shows a flap 22 at the connection point of the feed lines 16, 17 with the evaporator chamber 14 and the feed lines 25, 26 with the evaporator chamber 15 respectively. These flaps 22 can each be replaced by the same alternatives as described with reference to FIG. 1.

[0038] The temperature difference between the desired temperature of the crisper 24 and the evaporator 13 is even greater than that between the desired temperature of the standard refrigeration compartment 1 and the evaporator 11; the air, which flows back from the evaporator chamber 15 to the crisper 24, is correspondingly dry. With a temperature difference between crisper 24 and evaporator 13 of 20 C., the humidity in the crisper can be kept below 25%.

[0039] In the embodiment of FIG. 3 the evaporator chamber 15 is connected via the feed and return lines 26, 28 to the same chill compartment 2 as the evaporator chamber 14. All feed lines 16, 17, 25, 26 can in each case be blocked by a flap 29. In the illustration in FIG. 3 the flaps 29 of the feed lines 17, 25 are open and those of the feed lines 16, 26 are closed, so that the fan 20 drives an air flow over the chill compartment 3, while the standard refrigeration compartment 1 is cut off from the supply of cold air, and the fan 21 supplies the freezer compartment 2 with cold air. Since the temperature of the evaporator 11 is only slightly below that of the chill compartment 2, the relative humidity in the chill compartment 2 can be high.

[0040] If, instead, the user desires a low level of humidity in the chill compartment 2, he can make a corresponding adjustment at the control unit 23 (not shown in FIG. 3 for the sake of clarity); this reacts by permanently closing the flap 29 of the feed line 17 in order to separate the chill compartment 2 from the evaporator 11, and instead periodically switches over the flaps 29 of the feed lines 25, 26 to distribute the cold air from the evaporator 13 between the freezer compartment 3 and the chill compartment 2. Due to the low temperature of the evaporator 13 dry air thus passes into the chill compartment 2. The control unit 23 constricts the passage cross-section of the restrictor 12, moreover, in order to take into account the shift in refrigeration requirement from the evaporator 14 to the evaporator 15.

[0041] The embodiment in FIG. 4 combines features of the embodiments in FIGS. 2 and 3. As in the case of FIG. 2 there is the chill compartment 2, which shares the evaporator 14 with the standard refrigeration compartment 1, and the crisper 24, which shares the evaporator 15 with the freezer compartment 3. Chill compartment 2 and crisper 24 are surrounded by a shared inner container 30; the boundary between them is formed by a partition 31. The partition 31 can be mounted in various positions in the inner container 30, for example in the same way as conventional shelves, by resting on supporting projections 32 on the partitions of the inner container 30. Therefore, if required, by changing the position of the partition 31, one of the compartments 2, 24 can be enlarged and the other reduced in size.

[0042] The partition 31 can also be removed, so that just a single storage compartment remains in the inner container 30. As described with reference to FIG. 3, this can then optionally be operated as a chill compartment with a high or low level of humidity.

REFERENCE NUMERALS

[0043] 1 storage compartment (standard refrigeration compartment)

[0044] 2 storage compartment (chill compartment)

[0045] 3 storage compartment (freezer compartment)

[0046] 4 compression refrigeration machine

[0047] 5 compressor

[0048] 6 pressure connection

[0049] 7 suction connection

[0050] 8 coolant line

[0051] 9 liquefier

[0052] 10 restrictor

[0053] 11 evaporator

[0054] 12 restrictor

[0055] 13 evaporator

[0056] 14 evaporator chamber

[0057] 15 evaporator chamber

[0058] 16 feed line

[0059] 17 feed line

[0060] 18 return line

[0061] 19 return line

[0062] 20 fan

[0063] 21 fan

[0064] 22 flap

[0065] 23 control unit

[0066] 24 crisper

[0067] 25 feed line

[0068] 26 feed line

[0069] 27 return line

[0070] 28 return line

[0071] 29 flap

[0072] 30 inner container

[0073] 31 partition

[0074] 32 supporting projection