KR100913144B1 - Time divided multi-cycle type cooling apparatus - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a differential division multicycle type cooling device, and to optimize the cooling temperature of each cooling chamber by controlling the refrigerating chamber cooling and the freezing chamber cooling at a time difference. In the case of the refrigerator, the refrigerator compartment is cooled to the target temperature and the freezer compartment is cooled at the same time. When the refrigerator compartment is completed, the freezer compartment alone is cooled to obtain an appropriate cooling temperature for each of the refrigerator compartment and the freezer compartment.

Description

TIME DIVIDED MULTI-CYCLE TYPE COOLING APPARATUS}

1 is a side cross-sectional view of a refrigerator according to an embodiment of the present invention.

2 is a view showing a refrigerant circuit of the refrigerator shown in FIG.

3 is a block diagram of a control system centered on the control unit of the refrigerator illustrated in FIG. 1.

4 is a timing chart illustrating cooling mode control and natural defrost control of a refrigerator according to an embodiment of the present invention.

5 is a timing chart showing control when the ambient temperature of the refrigerator according to the embodiment of the present invention is a low temperature condition (eg, 15 ° C. or less).

Figure 6 is a flow chart showing a refrigerator compartment high humidity operation method when the ambient temperature of the refrigerator according to an embodiment of the present invention at a high temperature.

7 is a flowchart illustrating a defrosting method of a refrigerator compartment evaporator according to an operating time of a full cooling mode in a refrigerator according to an embodiment of the present invention.

8 is a timing chart illustrating defrost control of a refrigerator compartment evaporator and a freezer compartment evaporator in consideration of restarting of a compressor in a refrigerator according to an embodiment of the present invention.

9 is a timing chart showing the defrost control of the freezer compartment evaporator of the refrigerator according to the embodiment of the present invention.                 

* Description of the symbols for the main parts of the drawings *

102: compressor

104a, 104b: Defrost Heater

106: refrigerator compartment evaporator

108: freezer evaporator

110: refrigerator

120: freezer

202: condenser

204, 206, 208: capillary

210: 3-way valve

The present invention relates to a cooling device, comprising a cooling device having two or more cooling chambers, each cooling chamber is cooled independently.

In a cooling device having two or more cooling chambers, each cooling chamber is partitioned by an intermediate partition and opened and closed by a door. In addition, an evaporator for generating cold air and a fan for blowing the generated cold air into the cooling chamber are provided for each cooling chamber. Since all cooling chambers are cooled independently by the action of each evaporator and fan, such a cooling method is called an independent cooling method.                         

Typical cooling devices to which the independent cooling method is applied include a refrigerator having a freezer compartment and a refrigerating compartment. The freezer compartment of the refrigerator is mainly for storing frozen food, and a typical freezer compartment has a suitable temperature of about -18 ° C. In contrast, the refrigerating chamber is for storing general foods that do not require refrigeration at room temperature of 0 ℃ or more is about 3 ℃ is known to be appropriate.

Although the refrigerating compartment and the freezer compartment proper temperature are different from each other, in the conventional refrigerator, the evaporation temperatures of the refrigerating compartment evaporator and the freezer compartment evaporator are the same. For this reason, the freezer compartment fan is continuously operated, and the refrigerating compartment fan is intermittently operated to blow cold air into the refrigerating compartment whenever necessary so that the internal temperature of the refrigerating compartment is not lowered more than necessary.

Thus, even if the refrigerant evaporates continuously in the refrigerating compartment evaporator, the operation of the refrigerating compartment fan is intermittent, so that frost generated during the rest period of the refrigerating compartment fan is not supplied to the refrigerating compartment, but frost is formed on the surface of the refrigerating compartment evaporator. Cause. As frost is formed on the surface of the refrigerating chamber evaporator, the evaporation efficiency of the refrigerating chamber evaporator is lowered, and thus the cooling efficiency of the refrigerating chamber is lowered. In addition, even in the case where only cooling of the refrigerating compartment is required, the load of the compressor is unnecessarily large because the refrigerant must be compressed in consideration of the evaporation temperature required by the freezer compartment evaporator.

The differential jet multi-cycle cooling apparatus according to the present invention has an object to optimize the temperature of the freezer compartment and the refrigerating compartment by controlling the refrigerating compartment cooling and freezer compartment cooling with time difference.

The cooling device according to the present invention for this purpose includes a first and a second refrigerant circuit, a flow path switching device, and a control unit. The first refrigerant circuit is configured such that the refrigerant discharged from the compressor flows to the suction side of the compressor via the condenser, the first expansion device, the first evaporator, the second expansion device, and the second evaporator. The second refrigerant circuit is configured to allow the refrigerant passing through the condenser to flow to the suction side of the compressor via the third expansion device and the second evaporator to bypass the first expansion device, the first evaporator, and the second expansion device. The flow path switching device is installed on the discharge side of the condenser, and the flow path of the refrigerant is changed so that the refrigerant passing through the condenser flows through at least one refrigerant circuit of the first and second refrigerant circuits. The controller selectively opens and closes the flow path switching device to control the flow path of the refrigerant, and when the cooling device is powered on to supply power, the refrigerant flows through the first refrigerant circuit, and when the cooling through the first refrigerant circuit is completed, The flow path switching device is controlled to flow the refrigerant through the second refrigerant circuit.
In addition, the above-mentioned first to third expansion devices are capillaries.
In addition, the inner diameter of the above-mentioned second expansion device is smaller than the inner diameter of the suction side refrigerant pipe of the compressor.
In addition, the inner diameter of the above-mentioned second expansion device is 2 to 4 mm.
In addition, the flow path switching device is controlled to allow the refrigerant to flow through the above-described first refrigerant circuit, thereby allowing two different in each of the first and second evaporators through independent expansion of the refrigerant in each of the first expansion device and the second expansion device. A first cooling mode for obtaining two evaporation temperatures; And a second cooling mode for controlling the flow path switching device to flow the refrigerant through the second refrigerant circuit to obtain a single evaporation temperature in the second evaporator through expansion of the refrigerant by the third expansion device.
In addition, the decompression degree of the refrigerant formed in the above-described second and third expansion devices is a size for obtaining the evaporation temperature required by the second evaporator.
The first refrigerant circuit described above cools the refrigerating chamber and the freezing chamber, and the second refrigerant circuit cools only the freezing chamber.
The control method of the cooling apparatus according to the present invention includes a first refrigerant circuit configured to allow the refrigerant discharged from the compressor to flow to the suction side of the compressor via the condenser, the first expansion device, the first evaporator, the second expansion device, and the second evaporator; And a second refrigerant circuit configured to bypass the first expansion device, the first evaporator, and the second expansion device by passing the refrigerant passing through the condenser through the third expansion device and the second evaporator to the suction side of the compressor, and the discharge side of the condenser. A flow path switching device for switching the flow path of the refrigerant so as to flow through at least one of the first and second refrigerant circuits and the refrigerant passing through the condenser, and to control the flow path of the refrigerant by selectively opening and closing the flow path switching device. A control room of a cooling apparatus including a first cooling chamber cooled by a first evaporator and a second cooling chamber cooled by a second evaporator In the first through the refrigerant circuit controls the flow channel switching device, the refrigerant to flow, and cooling both the first and second cooling chamber; When the internal temperature of the first cooling chamber reaches the target temperature, the flow path switching device is controlled to flow the refrigerant through the second refrigerant circuit to cool the second cooling chamber alone; When the cooling device is powered on and power supply is started, the refrigerant flows through the first refrigerant circuit, and when the cooling through the first refrigerant circuit is completed, the flow path switching device is controlled to flow through the second refrigerant circuit.
In addition, when the internal temperature of the second cooling chamber reaches the target temperature, the compressor is stopped.
In addition, when the above-described operation of the compressor is stopped, the flow path switching device is controlled to close the second refrigerant circuit and open the first refrigerant circuit so that the compressed refrigerant already discharged from the compressor is supplied to the first refrigerant circuit.
And further comprising a first evaporator fan for blowing air around the first evaporator as described above into the first cooling chamber; When the temperature of the first cooling chamber is lower than or equal to the preset temperature in the state where the first refrigerant circuit is opened, the first evaporator fan is operated for a first set time to remove frost on the surface of the first evaporator.
In addition, the above-mentioned cooling apparatus removes the first defrost heater for removing defrost on the surface of the first evaporator, the first evaporator fan for blowing air around the first evaporator into the first cooling chamber, and the air around the second evaporator. A second evaporator fan for blowing into the cooling chamber; If the external temperature of the cooling device is lower than the preset temperature after opening the first refrigerant circuit, operating the first defrost heater for the first set time reduces the internal temperature of the first cooling chamber to be lower than the target temperature by the external temperature. prevent.
Further, when the above-described first refrigerant circuit is closed, if the external temperature of the cooling device is higher than or equal to a preset temperature, the first evaporator fan is operated for a second set time to remove frost on the first evaporator surface; At the same time, the humidity of the first cooling chamber is increased by operating the first evaporator fan to blow moisture generated during defrosting into the first cooling chamber.
In addition, the set temperature mentioned above is 15 degreeC.
In addition, when the cooling time through the first refrigerant circuit exceeds a preset time in a state where the temperature of the first cooling chamber does not reach the target temperature, the first refrigerant circuit is closed and the second refrigerant circuit is opened after a predetermined time. Operating the first evaporator fan for a period of time to defrost the first evaporator surface;
The control method of the cooling apparatus which closes a 2nd refrigerant circuit, reopens a 1st refrigerant circuit, and resumes cooling through a 1st refrigerant circuit after a predetermined time elapses.
In addition, the above-mentioned cooling apparatus further includes a second defrost heater and a condenser fan provided in the condenser for removing defrost on the surface of the second evaporator; When simultaneously removing the frost on the surfaces of the first and second evaporators after the compressor is stopped, the flow path switching device is controlled to open both the first and second refrigerant circuits and to operate the first and second defrost heaters to perform defrost. do.
In addition, the first and second evaporator fans are not operated while the above-mentioned first and second defrost heaters are operated.
In addition, when the frost on the surface of the second evaporator is removed alone after the compressor described above is stopped, the second refrigerant circuit is closed and the second refrigerant circuit is opened to allow the heated refrigerant of the condenser to flow into the second evaporator while the second compressor is removed. Start the defrost heater.
In addition, when the above alone defrosting of the second evaporator is completed, both of the first and second refrigerant circuits are opened to allow pressure equalization of the refrigerant over the entire first and second refrigerant circuits.
In addition, the heating temperature of the defrost heater described above is limited to within the target temperature of the first cooling chamber so that the temperature of the first cooling chamber does not exceed the target temperature.
In addition, when the above-described first setting time elapses, both the first and second refrigerant circuits are opened so that the pressure balance of the refrigerant is achieved over the entire first and second refrigerant circuits.
In addition, when the above-described defrost is completed and the operation of the first and second defrost heaters is stopped, the pressure of the refrigerant raised by the operation of the first and second defrost heaters is lowered by operating the first and second evaporator fans and the condenser fan. Smooth restart of the compressor.

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A preferred embodiment of the cooling apparatus and the control method according to the present invention made as described above will be described with reference to FIGS. 1 to 9. 1 is a side cross-sectional view of a refrigerator according to an embodiment of the present invention. As shown in FIG. 1, inside the refrigerator compartment 110, the refrigerator compartment evaporator 106, the refrigerator compartment fan motor 106a, the refrigerator compartment fan 106b, and the defrost heater 104a are provided. Inside the freezer compartment 120, a freezer compartment evaporator 108, a freezer compartment motor 108a, a freezer compartment fan 108b, and a defrost heater 104b are provided. The defrost heaters 104a and 104b are for melting and removing frost formed on the surfaces of the refrigerating chamber evaporator 106 and the freezing chamber evaporator 108, respectively.

Cold air generated in the refrigerator compartment evaporator 106 is blown into the refrigerator compartment 110 by the refrigerator compartment fan 106b. The cold air generated in the freezer compartment evaporator 108 is also blown into the freezer compartment 120 by the freezer compartment fan 108b. In addition, expansion devices (not shown) are installed at the inlet side of the refrigerator compartment evaporator 106 and the inlet side of the freezer compartment evaporator 108, and a condenser (not shown) is provided at the outlet side of the compressor 102. do.

FIG. 2 is a view illustrating a refrigerant circuit of the refrigerator illustrated in FIG. 1. As shown in FIG. 2, the compressor 102 and the condenser 202, the first capillary tube 204, the refrigerating chamber evaporator 106, the second capillary tube 206, and the freezing chamber evaporator 108 are connected through a refrigerant tube. A closed loop refrigerant circuit of is provided. That is, the refrigerator compartment evaporator 106 and the freezer compartment evaporator 108 are connected through the second capillary tube 206. The refrigerant passing through the condenser 202 passes through the third capillary tube 208 between the condenser 202 and the freezer compartment evaporator 108 such that the refrigerant is expanded under reduced pressure by the third capillary tube 208 and flows into the freezer compartment evaporator 108. Another closed loop refrigerant circuit is provided. Refrigerant flow control between the two refrigerant circuits is achieved through the three-way valve 210, which is a flow path switching device. In addition, a condenser fan motor 202a for driving the condenser fan 202b, a refrigerating chamber fan motor 106a for driving the refrigerating chamber fan 106b, and a freezer compartment fan motor 108a for driving the freezing chamber fan 108b are further provided. .

If the two evaporators 106 and 108 are connected only by the refrigerant pipe having the same inner diameter as the suction side refrigerant pipe of the compressor 102, the evaporation temperatures of the refrigerator compartment evaporator 106 and the freezer compartment evaporator 108 are the same in all cooling modes. In this case, when the evaporation temperature of the freezer compartment evaporator 108 is lowered in consideration of the cooling of the freezer compartment 120, frost is formed on the surface of the refrigerating compartment evaporator 106, and the evaporation temperature of the freezer compartment evaporator 108 is reduced to prevent frost. If the height of the freezer compartment 120 is not sufficiently cooled. This problem is solved by connecting the freezer compartment evaporator 108 and the refrigerator compartment evaporator 106 to the second capillary tube 206 as shown in FIG. 2.

The first capillary 204 reduces the pressure of the refrigerant passing through the condenser 202 so that the refrigerant can evaporate at the evaporation temperature required by the refrigerating chamber evaporator 106. The second capillary tube 206 further reduces the pressure of the refrigerant passing through the refrigerator compartment evaporator 106 to allow the refrigerant to evaporate at the evaporation temperature required by the freezer compartment evaporator 108. This is because the evaporation temperature required by the freezer compartment evaporator 108 is lower than the evaporation temperature required by the refrigerator compartment evaporator 106. The third capillary tube 208 reduces the pressure of the refrigerant passing through the condenser 202 to allow the refrigerant to evaporate at the evaporation temperature required by the freezer compartment evaporator 108. The third capillary tube 208 can evaporate the pressure of the refrigerant passing through the condenser 202 at the evaporation temperature required by the freezer evaporator 108, unlike once again reducing the pressure of the refrigerant depressurized by the primary pressure 204 once again. Immediately depressurize to the extent possible. To this end, the resistance of the third capillary tube 208 should be designed to be larger than the resistance of the second capillary tube 206. In conclusion, the degree of decompression of the refrigerant in each of the second capillary tube 206 and the third capillary tube 208 is determined in the freezer compartment. It must be to obtain the evaporation temperature required in the evaporator 108. In addition, the inner diameter of the second capillary tube 206 is designed to be smaller than the inner diameter of the suction side refrigerant tube of the compressor 102 (for example, about 2 to 4 mm) so that the refrigerant can be decompressed while passing through the second capillary tube 206. do. If the inner diameter of the second capillary tube 206 is too large, there is no significant difference in the evaporation temperatures of the two evaporators 106 and 108. On the contrary, if the inner diameter is too small, the refrigerant in the liquid phase and the gas phase are mixed in the refrigerating chamber evaporator 106. An excessively large resistance is generated in the flow, which slows down the cooling rate of the refrigerating chamber 110.

Such a refrigerator according to an embodiment of the present invention provides various cooling modes through control of a controller such as a microcomputer. 3 is a block diagram of a control system centering on the control unit 302 provided in the refrigerator according to the embodiment of the present invention. As shown in FIG. 3, a key input unit 304, a freezer compartment temperature detector 306, a refrigerator compartment temperature detector 308, and a refrigerator compartment evaporator temperature detector 322 are connected to an input port of the controller 302. The key input unit 304 is provided with a plurality of function keys, and these function keys include function keys related to setting of operating conditions of the refrigerator, such as setting a cooling mode or setting a desired temperature. The freezer compartment temperature detector 306 and the refrigerator compartment temperature detector 308 detect the temperatures in the freezer compartment 120 and the refrigerating compartment 110, respectively, and provide them to the controller 302. The refrigerator compartment evaporator temperature detector 322 detects and supplies the refrigerant evaporation temperature of the refrigerator compartment evaporator 106 to the controller 302.

The compressor driver 312, the freezer compartment fan driver 314, the refrigerator compartment fan driver 316, the three-way valve driver 318, the defrost heater driver 320, and the display 310 are connected to the output port of the controller 302. . The rest of the components except for the display unit 310 drives the compressor 102, the freezer compartment fan motor 108a, the refrigerating compartment fan motor 106a, the three-way valve 210, and the defrost heaters 104a and 104b, respectively. The display unit 310 displays an operating state of the cooling device, various set values, temperature, and the like.                     

The controller 302 controls the three-way valve 210 to circulate the refrigerant through at least one of the two refrigerant circuits shown in FIG. 2 to implement various cooling modes. Exemplary cooling modes that can be implemented in the refrigerator according to the embodiment of the present invention include a first cooling mode, a full cooling mode, and a second cooling mode, a freezer compartment cooling mode. The overall cooling mode is an operation mode in which both the refrigerating compartment 110 and the freezing compartment 120 are cooled. The control unit 302 opens only the first valve 210a of the three-way valve 210 to implement the full cooling mode, in which the discharge refrigerant of the condenser 202 is discharged from the first capillary tube 204 and the refrigerating chamber. Circulated through an evaporator 106, a second capillary 206, and a freezer compartment evaporator 108. The freezer compartment cooling mode is an operation mode in which only the freezer compartment 120 is cooled alone. The freezer compartment cooling mode is implemented by the control unit 302 opening only the second valve 210b of the three-way valve 210, in which the discharge refrigerant of the condenser 202 is discharged from the third capillary tube 208 and the freezer compartment evaporator. Circulating through 108 only.

Changes in the pressure of the refrigerant occurring in the overall cooling mode and the freezer compartment cooling mode of the refrigerator according to the embodiment of the present invention, and thus the change of the evaporation temperature in each of the evaporators 106 and 108 are as follows. When the first valve 210a of the three-way valve 210 is opened (the second valve 210b is closed) in the full cooling mode, the discharged refrigerant of the condenser 202 is firstly decompressed in the first capillary tube 204. First evaporate in the refrigerating compartment evaporator 106. The refrigerant evaporated first in the refrigerating compartment evaporator 106 is secondly depressurized while passing through the second capillary tube 206 and then secondly evaporated in the freezer compartment evaporator 108.

The evaporation temperature of the refrigerating chamber evaporator 106, as the inherent evaporation temperature required for each evaporator 106, 108 can be obtained through the stepwise depressurization of the refrigerant through the first and second capillary tubes 204, 206 in the full cooling mode. The overcooling of the refrigerating compartment evaporator 106 and the consequent defrosting of the resulting refrigerating compartment evaporator 106 caused when is equal to the evaporation temperature of the freezer compartment evaporator 108 is significantly reduced.

As mentioned above, the proper temperature of a general freezer compartment is about -18 ° C, and the optimum temperature of the refrigerator compartment is about 3 ° C. Since the difference between the proper temperature of the freezer compartment and the refrigerating compartment is large, if the evaporator temperature of each evaporator is increased to suppress overcooling of the refrigerating compartment, the freezer compartment may not be sufficiently cooled. In the cooling apparatus according to the present invention, when the cooling of the freezer compartment 120 is insufficient, only the freezer compartment 120 except for the freezer compartment 110 is cooled through a low evaporation temperature so that the internal temperature of the freezer compartment 120 quickly reaches a target temperature. Do it.

The freezer compartment cooling mode is for cooling the freezer compartment 120 alone. In this operation mode, when the second valve 210b of the three-way valve 210 is opened (the first valve 210a is closed), the condenser 202 Discharged refrigerant flows only through the third capillary tube 208 to the freezer compartment evaporator 108. In the freezer compartment cooling mode the refrigerant is depressurized to a lower pressure in the third capillary 208 and then evaporated in the freezer compartment evaporator 108. Further evaporation of the refrigerant by the third capillary tube 208 causes the evaporation temperature of the freezer compartment evaporator 108 to be lower than the evaporation temperature of the refrigerating compartment evaporator 106.

In the refrigerator according to an embodiment of the present invention, frost may accumulate on the surface of the refrigerating compartment evaporator 106 by operating for a long time even if the evaporation temperatures of the two evaporators 106 and 108 are minimized to minimize frosting. Differential-division multicycle type cooling apparatus according to the present invention removes the accumulated frost through the following control, and increases the humidity of the refrigerating chamber 110 by supplying the moisture generated in the defrosting process to the refrigerating chamber 110.

4 is a timing chart illustrating a cooling mode control and a natural defrost control of a refrigerator according to an embodiment of the present invention. As shown in FIG. 4, the first valve 210a is opened and the second valve 210b is closed at the initial stage of operation of the refrigerator in which the refrigerator in the power-off state is powered on to start power supply. Then, the first valve 210a is closed and the second valve 210b is opened to perform the freezer compartment cooling mode. That is, the refrigerator according to the embodiment of the present invention always performs the entire cooling mode first when power is supplied and starts operation, and then switches to the freezer compartment cooling mode. If the freezer compartment cooling mode is performed first, since the cooling of the refrigerating compartment 110 is delayed, the entire cooling mode is first performed in consideration of the cooling rate of the refrigerating compartment 110. It is also possible to carry out a full cooling mode and a freezer compartment cooling mode at the same time, but in this case the load on the compressor is greatly increased while the cooling rate is almost the same as the full cooling mode, which is not efficient.

When the operation of the compressor 102 is stopped after the freezer compartment cooling mode, the first valve 210a of the three-way valve 210 is opened and the second valve 210b is closed for t1 time shown in FIG. After the elapse of time, the second valve 210b is opened again. In the freezer compartment cooling mode, the refrigerating compartment evaporator 106 is close to a vacuum in which there is almost no refrigerant. Therefore, when the first valve 210a is opened while the compressor 102 is stopped, the refrigerator compartment evaporator 106 is compressed and discharged from the compressor 102. The high temperature refrigerant flows into the refrigerating chamber evaporator 106 which is like vacuum. As a result, the refrigerant flowing into the refrigerating chamber evaporator 106 is decompressed to some extent by the first capillary tube 204 for a predetermined time t1 immediately after the operation of the compressor 102 is stopped, thereby lowering the refrigerant evaporating temperature of the refrigerating chamber evaporator 106. . When the refrigerating compartment fan 106b is operated for such t1 hours, the refrigerating compartment 110 may be additionally cooled.

However, when the ambient temperature of the refrigerator is lower than the preset temperature (eg, 15 ° C. or less) at the time when the entire cooling mode is completed, the internal temperature of the refrigerator compartment 110 may be lowered below the target temperature. 5 is a timing chart illustrating control when the ambient temperature of the refrigerator according to the embodiment of the present invention is low (eg, 15 ° C. or less). As shown in FIG. 5, when the compressor 102 is stopped after the freezer cooling mode, when the temperature around the refrigerator is lower than a preset temperature (eg, 15 ° C. or lower), the first valve 210a is opened and the second The defrost heater 104a of the refrigerating compartment evaporator 106 is operated for the 1st set time t2 in the state which closed the valve 210b. In this case, even when the ambient temperature of the refrigerator drops below 0, the target temperature of the refrigerating chamber 110 may be maintained. At this time, the heating temperature of the defrost heater 104a is limited to below the set temperature of the refrigerating chamber 110 so that the internal temperature of the refrigerating chamber 110 does not exceed the target temperature by the heat of the defrost heater 104a. After the time t2 has elapsed, the defrost heater 104a is stopped while the second valve 210b is opened again, and the refrigerating compartment fan 106b is operated for the time t3. Here, the closing and reopening of the second valve 210b is to open the first and second valves 210a and 210b so that the pressure of the refrigerant is balanced throughout the refrigerant circuit.

In the refrigerator according to the embodiment of the present invention, when the entire cooling mode is completed, if the ambient temperature of the refrigerator is equal to or higher than a predetermined temperature (for example, 15 ° C.), the refrigerator compartment fan 106b is operated for a predetermined time to the refrigerator compartment evaporator 106. At the same time to remove the frost that is implanted at the same time the moisture generated during the defrosting in the refrigerating chamber 110 to perform a high humidity operation to increase the humidity of the refrigerating chamber (110). However, if the high humidity operation of the refrigerating chamber 110 is performed while the ambient temperature is too low, condensation may occur inside the refrigerating chamber 110, and the high humidity operation is performed only at a predetermined temperature or more. 6 is a flowchart illustrating a method of operating a refrigerator compartment high humidity when the ambient temperature of the refrigerator is high temperature according to an embodiment of the present invention. As shown in FIG. 6, when the entire cooling mode is completed (702 to 704), it is determined whether the external temperature of the refrigerator exceeds a preset temperature (706). If the outside temperature of the refrigerator exceeds the preset temperature, the refrigerator compartment fan 106b is operated for a predetermined time to perform the high humidity operation of the refrigerator compartment 110 (708), and then switch to the freezer compartment cooling mode (710).

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If the load of the refrigerating chamber is continuously increased due to frequent door opening in the entire cooling mode cooling both the refrigerating compartment 110 and the freezing compartment 120, the operation time of the full refrigerating mode 110 is maintained to maintain the target temperature of the refrigerating compartment 110. It must be long. If the operation time of the entire cooling mode is too long, the frost on the surface of the refrigerating chamber evaporator 106 accumulates and the cooling efficiency of the refrigerating chamber 110 is greatly lowered. Therefore, when the continuous operation time of the entire cooling mode is longer than the preset time, the refrigerator compartment fan 106b is operated to defrost the refrigerator compartment evaporator 106. 7 is a flowchart illustrating a defrosting method of a refrigerating compartment evaporator according to an operating time of a full cooling mode in a refrigerator according to an exemplary embodiment of the present invention. As shown in Fig. 7, the progress time of the entire cooling mode is counted while the entire cooling mode is performed (802 to 804 using a counter built in the control unit). If the progress time of the all-cooling mode exceeds the preset time (806), after switching from the all-cooling mode to the freezer compartment cooling mode (808), the refrigerator compartment fan 106b is operated to defrost the refrigerator compartment evaporator 106 (810). ). When the operation time of the refrigerating compartment fan 106b has elapsed in advance (812), the freezer compartment cooling mode is switched to the entire cooling mode again to perform cooling (814).

8 is a timing chart illustrating the defrost control of the refrigerator compartment evaporator 106 and the freezer compartment evaporator 9108 in consideration of restarting of the compressor in the refrigerator according to the embodiment of the present invention. Simultaneous defrosting of the refrigerator compartment evaporator 106 and the freezer compartment evaporator 108 during the idle period of the compressor 102 stops the operation of the compressor 102 and the fans 106b and 108b and the first of the three-way valves 210. And defrost heaters 104a and 104b provided for each of the evaporators 106 and 108 in a state where both the second valves 210a and 210b are opened. In this simultaneous defrosting process, the pressure of the refrigerant rises due to the heating of the defrost heaters 104a and 104b. If the pressure of the refrigerant is too high, restart of the compressor 102 after the completion of defrosting is not performed smoothly. Therefore, as shown in FIG. 8, defrost heaters 104a and 104b provided for each evaporator 106 and 108 are operated to remove frost formed, and when the defrost heaters 104a and 104b are finished, the condenser fan 202b is operated. ) And the freezer compartment 108b for a predetermined time to lower the temperature of the refrigerant heated by the defrost heaters 104a and 104b so that the pressure of the refrigerant is lowered. As the pressure of the refrigerant is lowered as described above, restart of the compressor 102 may be performed more smoothly. While the defrost heaters 104a and 104b are operating, the condenser fan 202b and the freezer compartment 108b are not operated to increase the heating effect of the defrost heaters 104a and 104b.

FIG. 9 is a timing chart illustrating a control method of defrosting a freezer compartment evaporator alone during a rest period of a compressor in a refrigerator according to an embodiment of the present invention. As shown in FIG. 9, the single defrost of the freezer compartment evaporator 108 closes the first valve 210a of the three-way valve 210 while the compressor 102 and the evaporator fans 106b and 108b are stopped. 2 is carried out with the valve 210b open. When the second valve 210b is opened, the high temperature refrigerant of the condenser 202 flows into the freezer compartment evaporator 108 through the third capillary tube 208 to increase the temperature. In this case, the load of the defrost heater 104b of the freezer compartment 120 is reduced, so that the defrost heater 104b may be operated less. Therefore, power consumption according to the operation of the defrost heater 104b may be reduced by that amount. When the defrost of the freezer compartment evaporator 108 is completed, the first and second valves 210a and 210b of the three-way valve 210 are opened for a predetermined time t5 before the compressor 102 is restarted, so that Allow the pressure of the refrigerant to equilibrate. When the time t5 has elapsed and the pressure balance of the refrigerant circuit has been achieved to some extent, the compressor 102 is restarted.

Through the cooling device and the control method according to the invention it is possible to obtain the following effects. First, in the case of a refrigerator, an appropriate cooling temperature for each of the refrigerator compartment and the freezer compartment can be obtained by cooling the refrigerating compartment and the freezer compartment through independent evaporation temperatures or by cooling only the freezer compartment alone, and suppressing overcooling of the refrigerating compartment. The operation of the refrigerator compartment fan and (or additionally) the defrost heater may be performed to defrost the refrigerating compartment evaporator in an operation mode in which only the freezing compartment is cooled alone, and the humidity generated in the defrosting process may be blown into the refrigerating compartment to increase the humidity of the refrigerating compartment. In addition, by eliminating frost on the surface of the refrigerating chamber evaporator by driving the refrigerating chamber fan for a predetermined time immediately after the compressor is stopped, the problem of frost caused by the refrigerant evaporation in the refrigerating chamber evaporator immediately after the compressor is stopped can be solved.

In addition, in the case of an air conditioner system having a plurality of indoor units, efficient air conditioning can be achieved by providing independent evaporation temperatures for each indoor unit requiring different cooling capabilities.

Claims (27)

A first refrigerant circuit configured to flow the refrigerant discharged from the compressor to the suction side of the compressor via the condenser, the first expansion device, the first evaporator, the second expansion device, and the second evaporator; A second refrigerant circuit configured to flow through the condenser to the suction side of the compressor via a third expansion device and the second evaporator to bypass the first expansion device, the first evaporator, and the second expansion device; ; A flow path switching device installed at a discharge side of the condenser and switching a flow path of the refrigerant so that the refrigerant passing through the condenser flows through at least one refrigerant circuit of the first and second refrigerant circuits; Selectively opening and closing the flow path switching device to control the flow path of the refrigerant, and when the cooling device is powered on to start supplying power, the refrigerant flows through the first refrigerant circuit, and the cooling through the first refrigerant circuit is completed. And a controller for controlling the flow path switching device to allow the refrigerant to flow through the second refrigerant circuit. delete delete delete The method of claim 1, And the first to third expansion devices are capillaries. The method of claim 1, And an inner diameter of the second expansion device is smaller than an inner diameter of the suction side refrigerant pipe of the compressor. The method of claim 6, Cooling device of the inner diameter of the second expansion device is 2 ~ 4mm. A first refrigerant circuit configured to flow the refrigerant discharged from the compressor to the suction side of the compressor through the condenser, the first expansion device, the first evaporator, the second expansion device, and the second evaporator; A second refrigerant circuit configured to flow through the expansion device and the second evaporator to the suction side of the compressor to bypass the first expansion device, the first evaporator, and the second expansion device; A flow path switching device for switching the flow path of the refrigerant so that the refrigerant passing through the condenser flows through at least one of the first and second refrigerant circuits, a control unit for selectively opening and closing the flow path switching device to control the flow path of the refrigerant; A first cooling chamber cooled by the first evaporator, and a second cooling chamber cooled by the second evaporator; In the control method of a cooling device, Cooling the first and second cooling chambers by controlling the flow path switching device to allow the refrigerant to flow through the first refrigerant circuit; Cooling the second cooling chamber alone by controlling the flow path switching device so that the refrigerant flows through the second refrigerant circuit when the internal temperature of the first cooling chamber reaches a target temperature; When the cooling device is powered on and power supply is started, the refrigerant flows through the first refrigerant circuit, and when the cooling through the first refrigerant circuit is completed, the flow path switching device such that the refrigerant flows through the second refrigerant circuit. Control method of the cooling device to control the. The method of claim 8, The control method of the cooling apparatus which stops operation of the said compressor when the temperature in the high temperature of the said 2nd cooling chamber reaches a target temperature. delete The method of claim 9, A cooling device which controls the flow path switching device to close the second refrigerant circuit and opens the first refrigerant circuit when the compressor stops operating so that the compressed refrigerant already discharged from the compressor is supplied to the first refrigerant circuit. Control method. delete The method of claim 11, A first evaporator fan for blowing air around the first evaporator into the first cooling chamber; A cooling device configured to remove frost on the surface of the first evaporator by operating the first evaporator fan for a first set time when the temperature of the first cooling chamber is lower than or equal to a predetermined temperature in the state where the first refrigerant circuit is opened. Control method. The method of claim 11, A first defrost heater for defrosting the surface of the first evaporator, a first evaporator fan for blowing air around the first evaporator into the first cooling chamber, and air around the second evaporator; A second evaporator fan for blowing into the second cooling chamber; After the first refrigerant circuit is opened, if the external temperature of the cooling device is lower than or equal to a preset temperature, the internal temperature of the first cooling chamber is increased by the external temperature by operating the first defrost heater for the first set time. A control method of the cooling device which prevents it from lowering below target temperature. The method of claim 8, Defrosting the surface of the first evaporator by operating the first evaporator fan for a second set time if the external temperature of the cooling device is above the preset temperature when the first refrigerant circuit is closed; And simultaneously operating the first evaporator fan to blow moisture generated in the defrosting into the first cooling chamber to increase the humidity of the first cooling chamber. The method according to claim 14 or 15, The control method of the cooling apparatus whose said set temperature is 15 degreeC. The method of claim 8, If the cooling time through the first refrigerant circuit exceeds a preset time in a state where the temperature of the first cooling chamber does not reach a target temperature, the first refrigerant circuit is closed and the second refrigerant circuit is opened after a predetermined time. Operating the first evaporator fan for a period of time to defrost the first evaporator surface; And closing the second refrigerant circuit, reopening the first refrigerant circuit, and resuming cooling through the first refrigerant circuit when the predetermined time elapses. The method of claim 9, The cooling device further comprises a second defrost heater for removing defrost on the surface of the second evaporator and a condenser fan provided in the condenser; When the frost on the surfaces of the first and second evaporators is simultaneously removed after the compressor is stopped, the flow path switching device is controlled to open both the first and second refrigerant circuits and the first and second defrost heaters. The control method of the cooling apparatus which moves and defrosts. The method of claim 18, And the first and second evaporator fans are not operated while the first and second defrost heaters are operating. The method of claim 9, When the frost on the surface of the second evaporator alone is removed after the compressor is stopped, the first refrigerant circuit is closed and the second refrigerant circuit is opened to flow heated refrigerant of the condenser into the second evaporator. The control method of the cooling device which operates the said 2nd defrost heater. The method of claim 20, And when the single defrost of the second evaporator is completed, open the first and second refrigerant circuits so that the pressure balance of the refrigerant is achieved throughout the first and second refrigerant circuits. The method of claim 1, The flow path switching device is controlled to allow the refrigerant to flow through the first refrigerant circuit so that the first and second evaporators are different from each other through independent expansion of the refrigerant in each of the first expansion device and the second expansion device. A first cooling mode for obtaining two evaporation temperatures; And a second cooling mode in which the flow path switching device is controlled to flow the refrigerant through the second refrigerant circuit to obtain a single evaporation temperature in the second evaporator through expansion of the refrigerant by the third expansion device. Device. The method of claim 1, And a depressurization degree of the refrigerant formed in the second and third expansion devices is a size for obtaining the evaporation temperature required by the second evaporator. The method of claim 14, And controlling the heating temperature of the defrost heater to be within the target temperature of the first cooling chamber so that the temperature of the first cooling chamber does not exceed the target temperature. The method according to claim 13 or 14, And the first and second refrigerant circuits are opened so that the pressure balance of the refrigerant is achieved over the entire first and second refrigerant circuits when the first set time elapses. The method of claim 18, When the defrost is completed and the operation of the first and second defrost heaters is stopped, the first and second evaporator fans and the condenser fan are operated to increase the pressure of the refrigerant raised by the operation of the first and second defrost heaters. A control method of the cooling device which lowers and makes restart of the said compressor smooth. The method of claim 1, And the first refrigerant circuit cools the refrigerating compartment and the freezing compartment, and the second refrigerant circuit cools only the freezing compartment.

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