KR20110086345A - A method for controlling a refrigerator with two evaporators - Google Patents

Abstract

PURPOSE: A method of controlling the operation of a refrigerator with two evaporators is provided to minimize increase in power consumption by rapidly lowering temperature of load in a refrigerating compartment and a freezing compartment to a predetermined value even right after defrosting operation. CONSTITUTION: A defrosting heater in an evaporator for a refrigerating compartment or another defrosting heater in an evaporator for a freezing compartment operates. After defrosting, the inner temperatures of the refrigerating compartment or the freezing compartment are measured by sensors. A cooling cycle is repeated by operation of a compressor. In the cooling cycle, a cooling operation for cooling the refrigerating compartment within a range of upper and lower limits around each reference temperature according to temperatures of the refrigerating and freezing compartments and a freezing operation for cooling the freezing compartment are made.

Description

A control method for a refrigerator having two evaporators {A METHOD FOR CONTROLLING A REFRIGERATOR WITH TWO EVAPORATORS}

The present invention relates to a method for controlling the operation of a refrigerator, and more particularly, in a refrigerator having two evaporators, a reference load according to the defrosting operation by adjusting the standard of the initial operation of the compressor after defrosting and the refrigeration operation during the defrosting of the refrigerator evaporator. The present invention relates to a method for controlling operation of a refrigerator capable of minimizing an increase in power consumption due to an increase in temperature.

In general, a refrigerator is a device that puts food in a freezer or a refrigerating compartment and keeps it fresh for a long time.

The refrigerator may be classified into a refrigerator having one evaporator installed in one freezer, and a refrigerator provided with two evaporators installed in the freezer compartment and a refrigerating compartment, respectively.

The refrigerator provided with the two evaporators respectively installs an evaporator in the freezing compartment and the refrigerating compartment to independently cool the refrigerating compartment and the freezing compartment.

The refrigerator selectively supplies the refrigerant to any one of two evaporators, and stops the operation of the compressor when the freezer compartment or the refrigerator compartment satisfies a preset condition in the controller.

The refrigerant flows selectively from the compressor to the refrigerating chamber evaporator and the freezing chamber evaporator through the three-way valve, the operation of the compressor is generally performed alternately between the refrigerating operation and the freezing operation.

The shift operation is to alternately repeat the refrigerating operation for cooling the refrigerating compartment and the freezing operation for cooling the freezing compartment in the range of the upper limit and the lower limit around the reference temperature according to the temperature of the refrigerating compartment and the freezing compartment. That is, the compressor is started when the temperature of the refrigerating chamber or the freezing chamber is equal to or higher than the upper limit, and the operation is stopped when the temperature is lower than the lower limit.

It is the compressor input that accounts for most of the input during the refrigeration cycle operation of the refrigerator.

On the other hand, when the refrigerating chamber evaporator and the freezing chamber evaporator perform the cooling operation by the refrigerating operation and the freezing operation for a long time, each of the evaporator is defrosted and the heat exchange efficiency of the evaporator is reduced, so that each evaporator is defrosted at regular intervals. Drive.

Defrosting operation is a series of processes to remove frost generated on the outer surface of the evaporator by using a defrost heater installed in each evaporator.

When the defrost of the evaporator is completed, the cooling operation must be performed again after passing a certain rest period.

However, in the defrosting operation, the stable load temperature increases with the cold air temperature around the heater as the defrost heater is heated. As a result, the load temperatures of the freezing compartment and the refrigerating compartment are increased.

When the load temperature is higher than the load temperature of the stable state before defrosting, power consumption increases.

In the related art, power consumption increases due to failure to quickly lower the elevated load temperature to a stable set temperature by continuing general operation before and after defrosting.

The present invention has been made to solve the above-described problems, and provides a refrigerator operation control method that can minimize the increase in power consumption by quickly lowering the load temperature of the refrigerator compartment and the freezer compartment to a stable set temperature even immediately after the defrosting operation. Its purpose is to.

Operation control method of the refrigerator according to the present invention for achieving the above object is to operate a compressor to compress the refrigerant flowing to each evaporator in a refrigerator including a compressor, a condenser, an expansion device and a refrigerator compartment evaporator and a freezer compartment evaporator. A method for controlling operation of a refrigerator, the method comprising: operating a defrost heater provided in the refrigerator compartment evaporator or a defrost heater provided in the freezer compartment evaporator; Measuring the internal temperature of the refrigerating compartment or the freezing compartment after the defrosting with a sensor; After the defrosting, the compressor is operated to alternately repeat a cooling cycle of refrigerating operation for cooling the refrigerating compartment and a freezing operation for cooling the refrigerating compartment, based on the temperature of the refrigerating compartment and the freezing compartment, based on the respective reference temperatures. Starting the compressor when the refrigerating or freezing compartment temperature reaches each reference temperature in the first and second cycles after defrosting; Starting the compressor when the temperature of the refrigerating chamber or the freezing compartment temperature becomes higher than the upper limit value after the third cycle after the defrosting, and stopping the operation of the compressor when the temperature becomes lower than the lower limit value.

In addition, after the defrosting of the freezer compartment evaporator, preferably further comprising the step of stopping the operation of the compressor when the freezer compartment temperature reaches 1 ° C lower than the lower limit in the first cycle and the second cycle after defrosting. Do.

The defrosting operation of the compressor during the defrosting of the refrigerating compartment evaporator is applied by changing the reference temperature of the cooling cycle to a temperature lower than 4 ° C., and the temperature of the freezing compartment is lower than the lower limit lower than the lower limit by the deviation from the changed reference temperature. It is further preferred to further comprise the step of stopping the operation of the compressor when a lower temperature is reached.

In addition, refrigeration operation of the compressor during defrosting the freezer compartment evaporator is applied by changing the reference temperature of the cooling cycle to a temperature lower than 4 ° C., and the temperature of the refrigerator compartment is lower than the lower limit lower by a deviation from the changed reference temperature. It is further preferred to further comprise the step of stopping the operation of the compressor when a lower temperature is reached.

According to the refrigerator operation control method of the present invention, even after the defrosting operation, the load temperature of the refrigerating compartment and the freezing compartment is quickly lowered to a stable set temperature, thereby minimizing an increase in power consumption.

1 is a schematic view showing the configuration of a cooling system of a refrigerator to which a control method according to the present invention is applied.
FIG. 2 is a graph showing a change in freezer load temperature when the freezer compartment temperature is greater than and smaller than that based on −18 ° C. when the ISO power test is performed in the refrigerator, and when the freezer compartment is alternately operated until the next defrost. .
Figure 3 is a graph showing the load temperature and power consumption of the freezer compartment when applying the control method according to the present invention.
4 is a graph showing the load temperature and power consumption of the refrigerating chamber when the control method according to the present invention is applied.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a schematic view showing the configuration of a cooling system of a refrigerator to which a control method according to the present invention is applied.

The refrigerator to which the control method according to the present invention can be applied includes a refrigerator compartment 40 and a freezer compartment 50 inside the body, and a refrigerator compartment evaporator 40 and a freezer compartment evaporator 50 at the rear of the refrigerator compartment and the freezer compartment, respectively. do.

As shown in FIG. 1, the cooling system of the refrigerator includes: a compressor (10) for sucking and compressing a low-temperature, low-pressure gaseous refrigerant to form a high-temperature, high-pressure gaseous refrigerant; A condenser 20 for dissipating heat into water or air from the high temperature and high pressure gaseous refrigerant discharged from the compressor and converting the heat into a high pressure saturated liquid refrigerant; A three-way valve 30 for allowing the refrigerant discharged from the condenser to selectively flow toward the refrigerating chamber evaporator 44 or the freezing chamber evaporator 54; A refrigerating compartment expansion device 42 and a freezing compartment expansion device 52 connected in parallel with the three-way valve 30; And a freezer compartment evaporator 44 connected to the expansion device 42 and installed at the rear of the refrigerating chamber and a freezer compartment evaporator 54 connected to the expansion device 52 and installed at the rear of the freezer compartment.

The condenser 20 is provided with a condenser fan 25 to promote heat exchange.

The three-way valve 30 allows the liquid refrigerant discharged from the condenser 20 to selectively flow to the refrigerating chamber evaporator 44 or the freezing chamber evaporator 54 connected in parallel.

The expansion devices 42 and 52 expand the high pressure liquid refrigerant discharged from the condenser 20 into a low temperature low pressure refrigerant.

The evaporator 44 is a refrigerator evaporator, which sucks and evaporates a low temperature low pressure refrigerant that has passed through the expansion device 42, and discharges cold air that has cooled down by heat exchange with ambient air. The evaporator 44 is provided with an evaporator fan 45 to promote heat exchange.

The evaporator 54 is a freezer compartment evaporator, while sucking and evaporating the low temperature low pressure refrigerant that has passed through the expansion device 52, and exchanging cold air by heat exchange with ambient air to the freezer compartment. Similarly, the evaporator 54 is provided with an evaporator fan 55 to promote heat exchange.

In addition, defrost heaters 47 and 57 are installed in the vicinity of the refrigerator compartment evaporator 44 and the freezer compartment evaporator 54 to remove frost generated on the surface of each evaporator during operation.

The defrost heaters 47 and 57 are not operated during the operation of the general cooling system but are only activated and heated when in the defrosting operation mode.

In addition, temperature sensors 41 and 51 are respectively installed in the refrigerator compartment and the freezer compartment of the refrigerator to measure the room temperature. The current room temperature measured by the temperature sensors 41 and 51 is sent to the control unit, and based on this, the control unit operates the cooling system to control the temperature of the refrigerating compartment and the freezing compartment to be in the proper temperature range.

On the other hand, the refrigerator has a top mount type in which a freezer compartment is disposed above the refrigerator compartment, a bottom freezer type in which the freezer compartment is disposed below the refrigerator compartment, and a freezer compartment and a refrigerator compartment according to the arrangement of the refrigerator compartment and the freezer compartment. It can be divided into a side by side type partitioned into left and right sides by the partition wall.

The control method of the present invention may be applied to all three types of refrigerators provided that the refrigerator and the freezer are each provided with an evaporator and a cooling system in which two evaporators are connected in parallel.

First, in the cooling system of the refrigerator including the refrigerator compartment evaporator 44 and the freezer compartment evaporator 54, the refrigerant is selectively flowed to each of the evaporators 44 and 54 through the three-way valve 30 while operating the compressor 10. A general operation control method of the refrigerator will be described.

In the refrigerator, the refrigerator compartment and the freezer compartment are controlled to a constant temperature by the operation of the cooling system. For example, the refrigerating compartment may be controlled to be maintained at about 5 ° C. and the freezer compartment may be controlled to be maintained at about −18 ° C.

To this end, when the target temperature is reached as the reference temperature and reaches a higher temperature (upper limit) by a deviation of 2 ° C., the three-way valve 30 is operated by the refrigerator compartment evaporator 44 or the freezer compartment evaporator while the compressor 10 is operated. 54 to be selectively connected to cool the refrigerating compartment 40 or the freezing compartment 50. Operating the cooling system while flowing the refrigerant to the refrigerating chamber evaporator 44 by the operation of the three-way valve 30 is called a refrigeration operation, and operating the cooling system while flowing the refrigerant to the freezing chamber evaporator 54 is refrigeration. It is called driving. Since the cooling system cools the refrigerating compartment or the freezing compartment through two evaporators 44 and 54 connected in parallel using one compressor 10, the refrigerating operation and the freezing operation are controlled to be alternately performed.

When the temperature of the refrigerating compartment or the freezing compartment becomes lower by 2 ° C. than the reference temperature (by reaching the lower limit) by the operation of the cooling system, the operation of the compressor 10 is stopped, and again by 2 ° C. above the reference temperature. If higher (the upper limit is reached), the same next cycle is performed again.

The deviation between the reference temperature and the reference temperature at which the cooling system is operated and stopped may vary depending on the capacity of the refrigerator, the use environment, or the presence of a special compartment maintained at a different temperature from other parts of the refrigerating or freezing compartment.

The operation control method of the refrigerator according to the present invention includes a compressor 10, a condenser 20, expansion devices 42 and 52, and a refrigerator including a refrigerator compartment evaporator 44 and a freezer compartment evaporator 54 to each evaporator. In the operation control method of the refrigerator operating the compressor 10 to compress the flowing refrigerant, the compressor 10 during the defrosting operation of the refrigerator compartment evaporator 44 or the freezer compartment evaporator 54 or immediately after the defrosting operation. The starting or stopping temperature is controlled differently from the control standard in normal shift operation.

In the defrosting operation, the defrost heater 47 installed near the evaporator 44 for the refrigerating compartment and the defrost heater 57 installed near the freezer evaporator 54 are heated to melt and remove frost attached to the surface of each evaporator. During the defrosting operation, the air temperature around the evaporator rises, so that the cooling system including the evaporator and the compressor is not operated or at least the refrigerant is not flowed toward the evaporator in which the defrost heater is operating.

The defrosting operation is controlled to be performed at regular intervals in consideration of the amount of frost generated in the evaporator while the cooling system alternately repeats the refrigerating operation and the freezing operation.

Figure 2 is a measure of the amount of power consumed by operating a refrigerator equipped with two evaporators for up to 72 hours in a state in which the load of the ice package (ice package) in the freezer in accordance with the ISO (International Organization for Standardization) according to the conditions according to the conditions Is a graph showing the change in freezer temperature during such a test.

As shown, in the case of the ISO power consumption test, as the defrost heater 57 is heated for a predetermined time during the defrosting operation, the freezer compartment load temperature, that is, the indoor temperature increases.

The freezer compartment load temperature rises by the heating of the defrost heater 57 when the control temperature is below -18 ° C (the lower one of the freezer compartment load temperature in FIG. 2), and a little more after the defrost heater stops heating. It rises to its maximum and then falls back below -18 ° C by the operation of the cooling system. It took about 4 hours from the point of passing -18 ° C (point B in the graph below) to the point of falling back to -18 ° C at a temperature lower than the reference temperature of -18 ° C.

Thereafter, the cooling system alternately performs the freezing operation and the cooling operation according to the room temperature of the freezing compartment and the refrigerating compartment. Normally, the compressor is stopped when the freezer load temperature drops below -18 ° C and passes the reference temperature to reach a temperature below -2 ° C below the reference temperature. Accordingly, the freezer compartment load temperature rises again to reach point A. In addition, when the temperature reaches 2 ° C. above the reference temperature, the compressor is started to start the cooling cycle of the cooling system. If the cooling cycle is repeated for some time, the freezer load temperature, like point C, is small and stabilized.

In FIG. 2, even when the freezer control temperature is -18 ° C. or higher, the freezer load temperature is increased by heating of the defrost heater, and then falls further below the control temperature of -18 ° C. or higher by the operation of the cooling system. When the load temperature reaches 2 ° C below the reference temperature, the compressor stops. When the temperature reaches 2 ° C above the reference temperature, the compressor is started and the cooling cycle of the cooling system begins.

However, in the present invention, when the defrost heater is heated at a predetermined cycle to defrost the refrigerating chamber evaporator or the freezing chamber evaporator, when the refrigerating chamber or freezing chamber temperature rising in the first cycle and the second cycle reaches each reference temperature + deviation (upper limit). The compressor is started even when the reference temperature is reached instead of starting the compressor.

Accordingly, by allowing the compressor to be started earlier than the original time in the first cycle and the second cycle after the defrosting operation, the reference load temperature after the defrosting can be lowered and stabilized.

After the third cycle, the compressor is started when the temperature of the refrigerating or freezing chamber reaches the upper limit as usual, and the compressor is stopped when the lower limit is reached.

In addition, the point of stopping the operation of the compressor in the first cycle and the second cycle of the cooling cycle after the defrost of the freezer compartment evaporator, unlike the usual case is to set when the freezer compartment temperature reaches 1 ° C lower than the lower limit. desirable.

Accordingly, the first cooling cycle and the second cooling cycle after the defrosting operation allow the operation of the compressor to start faster and stop later, so that it can quickly return to a stable load temperature state before the defrosting operation.

In the refrigerating operation of the compressor 10 during the defrosting of the refrigerating chamber evaporator 44, it is preferable to change the reference temperature of the cooling cycle to a temperature lower by 4 ° C.

Since the refrigerating chamber evaporator 44 and the freezing chamber evaporator 54 are connected in parallel, the three-way valve 30 connects the refrigerant flow path toward the freezing chamber evaporator 54 while the refrigerating chamber evaporator 44 is defrosted. The refrigerant does not flow toward the evaporator 44.

In this case, for example, when the reference temperature of the freezing operation is -18 ° C, the cooling system is operated by changing the reference temperature to -22 ° C, which is 4 ° C lower. If the deviation is 2 ° C, the compressor is started when the freezer temperature is -20 ° C and the compressor is stopped when -24 ° C.

In addition, it is more preferable to apply the cooling cycle by changing the operation stop time of the compressor from when the temperature reaches 0.5 ° C lower than the reference temperature.

As a result, the refrigeration operation during the defrost of the refrigerating chamber evaporator starts the compressor at -20 ° C in the above example and stops at -24.5 ° C. In other words, during refrigeration operation during defrost of the refrigerating compartment evaporator, the compressor is started at a lower temperature and its operation is stopped at a lower temperature.

Accordingly, it is possible to stabilize the freezer compartment temperature which is raised under the influence of the defrosting operation of the refrigerating compartment evaporator 44 quickly and stabilize, and minimize the increase in power consumption due to the increase in the reference load temperature of the freezer compartment.

Similarly, during the defrosting of the freezer compartment evaporator 54, the refrigeration operation of the compressor is preferably applied by changing the reference temperature of the cooling cycle to a temperature lower than 4 ° C.

In addition, it is more preferable to apply the cooling cycle by changing the operation stop time of the compressor from when the temperature reaches 0.5 ° C lower than the reference temperature.

For example, when the refrigeration operation has a reference temperature of 5 ° C., the reference system is changed to 1 ° C. lower than 4 ° C. to operate the cooling system. If the deviation is 2 ° C., the compressor is started when the refrigerator compartment temperature is 3 ° C. and the compressor is stopped when the temperature is 0.5 ° C., which is 0.5 ° C. smaller than 1 ° C.

Accordingly, it is possible to quickly lower and stabilize the refrigerator compartment temperature which is raised under the influence of the defrosting operation of the freezer compartment evaporator 54, and minimize the increase in power consumption due to the increase in the reference load temperature of the refrigerator compartment.

Figure 3 is a graph showing the load temperature and power consumption of the freezer compartment when applying the control method according to the invention, Figure 4 is a graph showing the load temperature and power consumption of the refrigerating compartment when applying the control method according to the present invention.

In the drawing, a line representing power located mainly below is indicated by a brown line, which is completely the same in FIGS. 3 and 4 since it represents power consumption of the refrigerator in the present invention.

In the graph, the time is displayed in minutes on the horizontal axis, and you can see that the power consumption spikes from 0 minutes and slightly after 800 minutes. This is when defrosting is performed by heating the defrost heater.

The rest of the cycle shows that power is repeatedly consumed when the compressor is operating as the cooling system alternates.

In FIG. 3, the freezer compartment load temperature was measured at six positions in the freezer compartment and the measured freezer compartment temperatures are indicated by TF1 to TF6.

In FIG. 4, the refrigerating compartment load temperature was also measured at three positions in the refrigerating compartment, and the measured refrigerating compartment temperatures are represented by TR1 to TR6.

According to the control method of the refrigerator according to the present invention, it can be confirmed that the freezer compartment temperature and the refrigerating compartment temperature are rapidly lowered and stabilized to a temperature when the stable state before defrosting or after the defrosting operation is performed after the defrosting operation.

According to the conventional control method before and after defrosting operation in a refrigerator having two evaporators, the power consumption increases by 2% when the reference load temperature rises by 1 ° C after defrosting the freezer evaporator, and the reference load temperature is 0.5 after defrosting the evaporator for the refrigerator compartment. When the power consumption increases by 1 ° C, the power consumption increases by 1 to 2%. According to the control method of the present invention, such an increase in power consumption can be virtually eliminated.

Although the preferred embodiment of the present invention has been described above, the scope of the present invention is not limited only to this specific embodiment, and those skilled in the art are appropriately within the scope described in the claims of the present invention. Changes will be possible.

10: compressor
20: condenser
25: condenser fan
30: three way valve
40: refrigerator
42: inflator
44: refrigerator evaporator
45: evaporator fan
47: Defrost heater
50: freezer
52: inflator
54: evaporator for freezer
55: evaporator fan
57: defrost heater

Claims (4)

In the operation control method of the refrigerator for operating the compressor to compress the refrigerant flowing to each evaporator in a refrigerator including a compressor, a condenser, an expansion device and a refrigerator compartment evaporator and a freezer compartment evaporator,
Defrosting by operating a defrost heater provided in the refrigerator compartment evaporator or a defrost heater provided in the freezer compartment evaporator;
Measuring the internal temperature of the refrigerating compartment or the freezing compartment after the defrosting with a sensor;
After the defrosting, the compressor is operated to alternately repeat a cooling cycle of refrigerating operation for cooling the refrigerating compartment and a freezing operation for cooling the refrigerating compartment, based on the temperature of the refrigerating compartment and the freezing compartment, based on the respective reference temperatures. Starting the compressor when the refrigerating or freezing compartment temperature reaches each reference temperature in the first and second cycles after defrosting;
Starting the compressor when the temperature of the refrigerating chamber or the freezing chamber becomes higher than the upper limit value after the third cycle after the defrosting, and stopping the operation of the compressor when the temperature becomes lower than the lower limit value. Way. The method of claim 1,
After defrosting the freezer evaporator,
And stopping the operation of the compressor when the freezer compartment temperature reaches 1 ° C. lower than the lower limit in the first and second cycles after defrosting. The method of claim 2,
The refrigeration operation of the compressor during the defrost of the refrigerating chamber evaporator,
Change the reference temperature of the cooling cycle to 4 ° C. and lower,
And stopping the operation of the compressor when the temperature of the freezer compartment reaches a temperature lower by 0.5 DEG C than the lower limit lowered by the deviation from the changed reference temperature. The method of claim 2,
The refrigeration operation of the compressor during the defrost of the freezer compartment evaporator,
Change the reference temperature of the cooling cycle to 4 ° C. and lower,
And stopping the operation of the compressor when the temperature of the refrigerating chamber reaches a temperature lower by 0.5 DEG C than the lower limit lowered by the deviation from the changed reference temperature.

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