DE102017221865A1 - Single-circuit refrigerating appliance - Google Patents

Abstract

A refrigeration device, in particular household refrigerating appliance, comprises a first cooling compartment (4), a second cooling compartment (3), a third cooling compartment (2) and a refrigerant circuit, in which a first evaporator (9) of the first cooling compartment (4) a second evaporator (8 ) of the second cooling compartment (3) via a first capillary (14) is connected in series. The third evaporator (7) in the refrigerant circuit upstream of the second evaporator (8) via a second capillary (13) in series.

Description

The present invention relates to a single-circuit refrigeration device. Such refrigerators are particularly in demand in countries with low purchasing power, since they can be offered inexpensively due to their simple structure. They usually comprise a normal refrigerator compartment and a freezer compartment, with an evaporator of the freezer compartment connected in series with the normal refrigerator compartment, so that the evaporator of the standard refrigerator compartment is cooled essentially only by the liquid refrigerant residue which has not been consumed in the freezer compartment evaporator. The temperature of the normal refrigeration compartment evaporator is therefore at least locally similar to that of the freezer compartment evaporator, and the large difference between the operating temperature of the normal refrigeration compartment and the evaporator temperature leads to a strong drying out of the normal refrigeration compartment. Therefore, the normal refrigeration compartment is not suitable to be contained therein e.g. Store vegetables without packaging that protects against dehydration.

It is known per se to set different evaporation temperatures in the evaporator of the normal refrigerator and freezer by the evaporator of the normal refrigeration compartment in the refrigerant circuit upstream of the evaporator of the freezer and between both an expansion valve is inserted, with the different pressures in the two evaporators can be maintained. However, the expansion valves are expensive and their control consuming, so they largely negate the cost advantage of the conventional single-circuit refrigeration device.

Out DE 10 2015 218 452 A1 a single-circuit refrigeration device is known in which the expansion valves are replaced by capillaries and the lack of controllability of the capillaries is compensated by the evaporators fans are assigned, which allow to modulate the cooling capacity of the evaporator respectively according to the cooling requirements of the individual compartments.

Object of the present invention is to provide a cost-effective refrigeration appliance with extended applications.

The object is achieved by a third cooling compartment with a third cooling compartment having a first cooling compartment, a second cooling compartment and a refrigerant circuit, in which a first evaporator of the first cooling compartment is connected downstream of a second evaporator of the second cooling compartment via a first capillary Evaporator is provided and the third evaporator in the refrigerant circuit is connected upstream of the second evaporator via a second capillary in series. Thus, three different temperature ranges can be provided, among which a user can select the most appropriate for a given chilled goods, and excessive, useless cooling power consuming dehydration can be avoided in all temperature ranges.

Preferably, the first cooling compartment is a freezer compartment and the second compartment is a normal refrigeration compartment. For the third evaporator is then characterized in that it is upstream of the evaporator of the normal refrigeration compartment, a higher evaporation temperature than in the latter, so that the operating temperature of the third compartment is higher than that of the normal refrigeration compartment. Such a compartment is well-suited, especially in countries with a warm climate, to accommodate drinks or delicate foods, such as tropical fruits, which deteriorate when stored in a standard normal refrigeration compartment, but can not be stored at ambient temperature without being quickly stored to spoil.

For the above purposes, an operating temperature of the third compartment above 10 ° C, especially above 12 ° C, is preferred. The refrigerant demand for the temperature of such a compartment is low, so that the presence of the third compartment on the operation of normal refrigerator and freezer compartment hardly affects.

In a conventional single-circuit refrigerator, the compressor is controlled by the temperature of the warmer compartment, as its refrigeration demand varies more than that of the colder compartment with ambient temperature. In the apparatus according to the invention, the compressor is controlled by a temperature sensor, which is arranged on the second cooling compartment, ie the one with medium operating temperature, as caused by changing ambient temperature fluctuations in the third compartment only slightly affect the shelf life of the food and therefore there rather than in the second Compartment can be tolerated.

In order to keep the cost of the device low, it is preferred to use coldwall evaporators, i. plate-shaped evaporator, which are embedded between a cooling container defining an inner container and a surrounding inner container insulating material layer.

A defrost heater may be provided on the second evaporator, since defrosting of ice which precipitates there is possible with little use of heating energy and in particular without heating the second compartment beyond its intended operating temperature.

It is also conceivable to provide a temperature sensor on the second evaporator, which prevents a start of the compressor, as long as the temperature of the second evaporator is below 0 ° C. Thus it can be ensured that the second evaporator does not cool again until defrosted frost has completely defrosted in a preceding cooling phase; the defrost heater is then superfluous.

Despite the lower temperature there is expediently no defrost heating provided on the first evaporator, since this evaporator can not be defrosted without heating the first compartment above its operating temperature. To defrost the first evaporator, the unit should be turned off.

The defrost heater of the second evaporator may be associated with a manually operable switch on which a user may initiate a defrost operation. In order for such a defrosting process does not hinder the cooling operation, a control unit should also be provided, which activates the defrost heater only when the compressor is stopped when the switch is actuated when the compressor is running.

To compensate for fluctuating refrigerant demand, the refrigerant circuit should have an accumulator downstream of the first evaporator.

• 1 zeigt ein Blockdiagramm eines erfindungsgemäßen Kombinationskältegeräts.

Further features and advantages of the invention will become apparent from the following description of embodiments with reference to the accompanying drawings.

• 1 shows a block diagram of a combination refrigerator according to the invention.

The refrigeration device of 1 includes in a housing 1 three storage compartments, a slightly refrigerated compartment 2 , a standard refrigerator 3 and a freezer 4 , The housing 1 comprises one or more inner containers in a manner known per se 5 which the storage compartments 2 . 3 . 4 limit, and one the inner container 5 surrounding insulation material layer 6 , Evaporator 7 . 8th . 9 for cooling a compartment 2 . 3 or. 4 are each between the inner container 5 the relevant compartment and the insulating material layer 6 embedded. The evaporators 7 . 8th each extend only on a rear wall of the compartment 2 or. 3 , the evaporator 9 of the freezer compartment 4 can also be as shown on the side walls or on the floor and ceiling of the freezer 4 extend.

The evaporators are connected in series in a refrigerant circuit. Starting from a pressure connection of a compressor 10 follow each other in the refrigerant circuit: a condenser 11 , a capillary 12 , the evaporator 7 of the slightly cooled compartment 2 , a capillary 13 , the evaporator 8th of the standard refrigerator compartment 3 , a capillary 14 , the evaporator 9 of the freezer compartment 4 , an accumulator 15 and a suction port of the compressor 10 , Pressure drops in the capillaries 13 . 14 ensure as long as the compressor 10 is in operation, from the evaporator 7 to the evaporator 9 gradually decreasing pressures and evaporation temperatures. These evaporation temperatures are each a few degrees below those in the subjects 2 . 3 . 4 maintain operating temperatures, but preferably above the operating temperature of each next colder compartment 3 or 4 ,

The pressure drops in the capillaries 12 and 13 are dimensioned to be at normal ambient temperatures and one for the normal refrigeration compartment 3 set temperature of 5 ° C a temperature of about 15 ° C in the slightly cooled compartment 2 to achieve. Such a refrigerated compartment can significantly increase the shelf life of sensitive foods that are too cold for the standard refrigerator compartment, typically 3-8 ° C, especially when the only other alternative is storage at an ambient temperature well above that Operating temperature of the slightly cooled compartment 2 lies. Since, therefore, the field of application of the refrigerator according to the invention are preferably countries with a warm climate, the "normal ambient temperatures" for which the refrigerant circuit is designed, can be well above 20 ° C.

At the evaporator 8th is a defrost heater 16 provided, for example in the form of a film heater, between the evaporator 8th and the inner container 5 is inserted to that part of the wall of the inner container 5 to be able to heat, at which the evaporator 8th and therefore can form ice under its influence.

The proportion of the surface of the inner container 5 , which is covered by the evaporator and can therefore form ice on it, is at the normal refrigeration compartment 3 significantly smaller than the freezer compartment evaporator 9 , While the latter one or more walls of the inner container 5 of the freezer compartment 4 almost completely covered, takes the evaporator 8th only an upper part of a wall of the inner container 5 of the standard refrigerator compartment 3 a, and in the lower part of the same wall is a gutter 17 , If one at the level of the evaporator 8th on the inner container 5 Defeated ice layer under the influence of the defrost heater 16 Antaut, it can slip on the wall to its lower in operation not cooled below 0 ° C lower range. The amount of heat needed to make the evaporator 8th freeing them from ice is therefore much smaller than the amount of heat required to thaw the ice. Instead, carry the slipped ice by placing it in the gutter 17 slowly thaws, to cover the cooling requirements of the normal refrigeration compartment 3 and thus reduces the energy consumption of the device.

From the bottom of the gutter 17 extends in a conventional manner, a drain line 18 through the insulating material layer 6 into the open, over which the condensation water into a shell 19 can drain, in which it takes advantage of waste heat of the compressor 10 evaporates.

A control unit 20 controls the operation of the compressor 10 on the basis of a sensor 21 determined temperature of the normal refrigeration compartment 3 , This control can consist in that the compressor 10 is always turned on when one of a user at a user interface 22 set nominal temperature of the standard cooling compartment 3 is exceeded by more than a permissible level, and is switched off again when reaching a slightly below the set temperature switch-off.

The user interface 22 further includes a switch 23 A user can press to defrost the evaporator 8th trigger. The control unit 20 responds to an actuation of the switch by the defrost heater 16 energized until the ice layer in front of the evaporator 8th is thawed from the back and on the between her and the inner container 5 slips off formed layer of water. The time required for this is largely independent of the thickness of the ice layer, therefore, the shutdown of the heating can be timed after a predetermined period of operation.

If, at the time of actuation of the switch, the compressor 10 is in operation, the control unit waits 20 before switching on the defrost heater 16 at least turning off the compressor 10 from. Expediently, in addition, a further waiting time can be maintained, or switching on the defrost heater can be delayed until the set temperature of the normal refrigeration compartment 3 is reached again. Thus, before the start of the defrost still a temperature balance between the evaporator 8th and the compartment he cooled 3 take place, which further reduces the energy required for defrosting.

According to an alternative embodiment, the defrost heater 16 replaced by a second temperature sensor 24 , which is directly at the evaporator 8th arranged, for example between the evaporator 8th and the insulating material layer 6 embedded and with the control unit 20 connected to a start of the compressor 10 to lock as long as the temperature of the evaporator 8th is below 0 ° C. As long as this is the case, heat flows from the compartment 3 to the evaporator 8th off, so even if that from the sensor 21 detected temperature of the compartment 3 well above the setpoint temperature, the cooling requirement of the compartment 3 despite standing compressor 10 at least partially covered. A frost layer, resulting in the previous phase of operation of the compressor 10 on the evaporator 8th Thus, even without the use of a heater, it completely defrosts before the compressor 10 starts up again.

The relative duty cycle of the compressor 10 depends on the heat flow to that of the temperature sensor 21 supervised compartment 3 and therefore also from the ambient temperature. The likelihood that due to low outside temperature, this relative duty cycle becomes too low, to a temperature of -18 ° C or below in the freezer compartment 4 to be able to maintain, is low, since the slightly cooled compartment 2 is primarily useful at high ambient temperatures and therefore is to be expected that the device is used primarily in a warm climate zone.

LIST OF REFERENCE NUMBERS

1

casing

2

slightly refrigerated compartment

3

Normal refrigeration compartment

4

freezer

5

inner container

6

Insulating material layer

7

Evaporator

8th

Evaporator

9

Evaporator

10

compressor

11

condenser

12

capillary

13

capillary

14

capillary

15

accumulator

16

defrost heater

17

collecting channel

18

drain line

19

Bowl

20

control unit

21

sensor

22

User interface

23

counter

24

temperature sensor

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102015218452 A1 [0003]

Claims (10)

Refrigerating appliance, in particular domestic refrigerator, comprising a first cooling compartment, a second cooling compartment and a refrigerant circuit, in which a first evaporator (9) of the first refrigerating compartment is connected downstream of a second evaporator (8) of the second cooling compartment via a first capillary (14) in series, characterized characterized in that it has a third cooling compartment (2) with a third evaporator (7) and the third evaporator (7) in the refrigerant circuit upstream of the second evaporator (8) via a second capillary (13) in series. Refrigeration device after Claim 1 , characterized in that the third evaporator (7) is preceded by a third capillary (12). Refrigeration device after Claim 1 or 2 , characterized in that the first cooling compartment is a freezer compartment (4) and the second compartment is a normal refrigeration compartment (3). Refrigerating appliance according to one of the preceding claims, characterized in that the operating temperature of the third cooling compartment (2) above 10 ° C, in particular above 12 ° C, is located. Refrigerating appliance according to one of the preceding claims, characterized in that a compressor (10) of the refrigerant circuit is controlled by a temperature sensor (21) arranged on the second cooling compartment. Refrigerating appliance according to one of the preceding claims, characterized in that the evaporators (7, 8, 9) are coldwall evaporators. Refrigerating appliance according to one of the preceding claims, characterized in that a defrost heater (16) is provided on the second evaporator (8). Refrigeration device after Claim 7 , characterized in that the defrost heater (16) is associated with a manually operable switch (23) and a control unit (20), which, when the switch (23) is operated with the compressor (10), the defrost heater (16) after Standstill of the compressor (10) activated. Refrigerating appliance according to one of the preceding claims, characterized in that on the second evaporator (8), a temperature sensor is provided which prevents the start of a compressor (10) as long as the temperature of the second evaporator (8) is below 0 ° C. Refrigerating appliance according to one of the preceding claims, characterized in that the refrigerant circuit has an accumulator (15) downstream of the first evaporator (9).

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