KR101677635B1 - Device for defrosting of refrigerator and method for defrosting thereof - Google Patents

Abstract

The present invention relates to a defrosting apparatus for a refrigerator and a defrosting method thereof. The present invention is characterized in that a valve for limiting the flow of the refrigerant is provided between the evaporator and the condenser before the defrosting operation is started so that the defrosting operation is performed for the evaporator in a state where the refrigerant is not left in the evaporator It is possible to shorten the time, thereby preventing the rise of the internal load temperature, thereby reducing power consumption. In addition, the refrigerant in the evaporator is prevented from being heated and expanded during the defrosting operation, thereby preventing the suction loss in the compressor, thereby improving the efficiency of the refrigerator.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a defrosting apparatus and a defrosting apparatus using the defrosting apparatus,

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a refrigerator, and more particularly, to a defrosting device for a refrigerator that removes gasses formed in an evaporator and a defrosting method using the same.

As is well known, a refrigerator is a device that allows food to be kept fresh by refrigeration or freezing. The refrigerator may include a refrigerator body having a plurality of cooling chambers formed therein, doors for opening and closing the respective cooling chambers, and a refrigeration cycle device for providing cool air to the cooling chambers.

The refrigeration cycle apparatus generally includes a compressor for compressing refrigerant, a condenser for condensing the refrigerant by radiating heat, an expansion device for expanding the refrigerant under reduced pressure, and an evaporator for evaporating the refrigerant by absorbing the latent heat of the surrounding refrigerant Device.

A cool air circulation channel is formed on the rear wall of the cooling chamber so that the cool air can circulate in the cooling chamber. An evaporator can be installed in the cool air circulation channel so that the cooling fan and the air can be cooled while allowing air to flow therethrough . The evaporator may be provided in each of a plurality of cooling chambers.

On the other hand, when the use time has elapsed, moisture in the air may condense (congeal) on the surface of the evaporator, the wall around the evaporator, the cooling fan, and the like. In the case of water condensation, not only the heat exchange between the air and the refrigerant is interrupted but also the flow resistance of the air is increased. Also, the moving parts of the cooling fan may freeze and the cooling fan may be restricted.

In the above conventional refrigerator, a so-called defrosting operation is performed in which the defrost heater is disposed on one side (for example, the lower side) of the evaporator to remove the defrosting. In the defrosting operation, power is applied to the defrost heater while the refrigeration cycle apparatus is stopped, and the impurities cast on the surface of the evaporator or around the evaporator are removed by using the heat generated from the defrost heater.

However, in the conventional defrosting method as described above, since the defrosting operation is performed in the state that the evaporator is filled with the refrigerant, the low temperature refrigerant filled in the evaporator as well as the evaporator is heated together with the defrosting operation. Not only the power consumption is increased but also the defrosting operation is longer and the temperature of the cooling chamber is increased and the power consumption of the refrigeration cycle device is increased as the load of the refrigerator is increased.

Further, as the defrost heater is operated in a state where the evaporator is filled with the refrigerant, the temperature of the evaporator refrigerant rises and the expanded refrigerant is sucked into the compressor through the recovery of the refrigerating cycle device, thereby lowering the initial performance of the compressor, There was also a problem.

It is an object of the present invention to provide a refrigerator which can prevent a refrigerant from remaining in the evaporator during a defrosting operation to shorten the defrosting operation time thereby to reduce power consumption and prevent the refrigerant from being re- And to provide a defrosting device and a defrosting method of the refrigerator which can enhance the defrosting performance of the refrigerator.

In order to achieve the object of the present invention, there is provided a defrosting apparatus for a refrigerator which defrosts by heating an evaporator, wherein a defrosting of the refrigerator is provided between the evaporator and the condenser, Device.

In order to accomplish the object of the present invention, there is provided a method for controlling a defrost operation, Closing the inlet side of the evaporator to block the inflow of the refrigerant; Heating the evaporator to perform defrosting; Stopping heating of the evaporator; And opening the inlet side of the evaporator to allow inflow of the refrigerant.

The defrosting device and the defrosting method of the refrigerator according to the present invention can reduce the defrosting operation time for the evaporator by performing the defrosting operation without leaving the refrigerant in the evaporator, The power consumption can be reduced.

In addition, the refrigerant in the evaporator is prevented from being heated and expanded during the defrosting operation, thereby preventing the suction loss in the compressor, thereby improving the efficiency of the refrigerator.

1 is a perspective view schematically showing a refrigerator having a defrosting device of the present invention,
FIG. 2 is a system diagram showing a refrigeration cycle apparatus of a refrigerator according to FIG. 1;
FIG. 3 is a front view showing the evaporators according to FIG. 1;
FIG. 4 is a schematic view showing a control unit of the refrigerator according to FIG. 1;
FIG. 5 is a block diagram showing a defrosting process in the refrigerator according to FIG. 1;
6 and 7 are a systematic diagram showing an example in which an oil pump or an oil separator is installed on the front and rear sides of the compressor in the refrigeration cycle apparatus according to FIG.
FIG. 8 is a schematic view showing another embodiment of the control unit of the refrigerator according to FIG. 1; FIG.

Hereinafter, a defrosting apparatus and a defrosting method of a refrigerator according to the present invention will be described in detail with reference to an embodiment shown in the accompanying drawings.

FIG. 1 is a perspective view schematically showing a refrigerator having a defrost apparatus according to the present invention, FIG. 2 is a system diagram showing a refrigeration cycle apparatus of a refrigerator according to FIG. 1, FIG. 3 is a front view showing evaporators according to FIG. 1, 4 is a schematic view showing a control unit of the refrigerator according to FIG. 1, and FIG. 5 is a block diagram showing a defrosting process in the refrigerator according to FIG.

1, a refrigerator having a defrosting device according to the present invention includes a refrigerator main body 1 having a cooling chamber formed therein, a refrigerator door 2 coupled to the refrigerator main body 1 to open and close a cooling chamber, And a refrigeration cycle device 3 provided in the refrigerator main body 1 for generating cold air.

Although the refrigeration cycle apparatus 3 can be variously classified according to an actual model of a refrigerator, a so-called '2-eva' type refrigeration cycle apparatus having an evaporator in each of the freezing and refrigerating chambers, as shown in FIG. 1, Take an example.

The refrigeration cycle apparatus includes a compressor 31 for compressing a refrigerant, a condenser 32 connected to the compressor 31 for condensing the compressed refrigerant, and a condenser 32 branched from the condenser 32, A second inflator (34) installed in the middle of the first inflator (33) and the second branch pipe (L2) for expanding the refrigerant and expanding the refrigerant; and a second inflator A first evaporator 35 for evaporating the refrigerant and a second evaporator 36 connected to the second inflator 34 for evaporating the refrigerant. The first evaporator (35) and the second evaporator (36) are integrated again and connected to the suction side of the compressor (31).

The flow direction of the refrigerant is controlled in the direction of the first evaporator 35 or the second evaporator 36 at the outlet of the condenser 32, that is, at the branch point divided into the first branch tube L1 and the second branch tube L2. A refrigerant switching valve 37 is provided.

The refrigerant switching valve 37 may be a three-way valve or a four-way valve. Of course, the refrigerant switching valve 37 may not be provided at the branch point but may be independently installed in the middle of each of the branch pipes L1 and L2. In this case, the refrigerant switching valve 37 is a one- Lt; / RTI >

The refrigerant switching valve 37 is electrically connected to a control unit, that is, a microcomputer 4, which controls the entire refrigeration cycle so as to determine the opening and closing direction of the refrigerant switching valve 37 or fully open or close the refrigerant switching valve 37. I will explain about the microcomputer later.

The first evaporator 35 and the second evaporator 36 may be installed in the rear wall of the cooling chamber, that is, the freezer compartment and the refrigerating compartment, and the first evaporator 35 and the second evaporator 36 The cooling air inlets and the cold air outlets may be formed so as to communicate with the respective evaporation chambers in which the cooling air is introduced.

The first evaporator 35 and the second evaporator 36 may be formed in a tube-fin shape having a heat transfer tube and a heat transfer fin, respectively. For example, as shown in FIG. 3, the first evaporator 35 may include a heat transfer tube 351 through which refrigerant flows, and a plurality of heat transfer fins 352 inserted into the heat transfer tube 351.

The heat transfer tubes 351 may include a plurality of straight tube portions 355 arranged in parallel to each other and a plurality of curved connecting tube portions 356 connecting the straight tube portions 355 to each other. Each of the heat conductive fins 352 may be spaced at a predetermined pitch along the longitudinal direction of the straight pipe portion 255. The pitch of the heat conductive fins 352 is formed such that the pitch on the upstream side is larger than the pitch on the downstream side, thereby preventing the flow resistance of the air from increasing due to the sex. A defrost heater 353 may be disposed below the heat transfer pipe 351.

A temperature sensor 354 for detecting the temperature of the evaporator is installed in the heat transfer pipe 351 or the heat transfer fin 352 to determine whether the defroster is defrosted, 354 may be electrically connected to the microcomputer 4 for controlling the defrosting operation of the evaporator.

4, the microcomputer 4 includes an input unit 41 for receiving the evaporator temperature from the temperature sensor 354, and a controller 41 for comparing the detected temperature of the evaporator delivered by the input unit 41 with the set temperature, A control unit for controlling the operation of the compressor and controlling the operation of the defrost heater 353 according to the contents determined by the determination unit 42, And a command section 43 for instructing the command.

A first defrost heater 353 and a second defrost heater (not shown) are respectively installed below the first evaporator 35 and the second evaporator 36. The first defrost heater 353 and the second defrost heater The heater 353 may be electrically connected to the command unit 43 of the microcomputer 4.

The defrost heater 353 (not shown) may be provided with a heat ray inside a pipe formed of a material such as aluminum that is easy to transfer heat and easily deformed by plastic deformation.

L3, which is not shown in the figure, is a hot line.

The defroster of the refrigerator according to the present invention as described above is operated as follows.

That is, the temperature sensor 354 (not shown) detects temperature changes of the evaporators 35 and 36 in real time or periodically and inputs them to the input unit 41 of the microcomputer 4. Then, the determination unit 42 of the microcomputer 4 compares the input detected temperature and the preset temperature in real time or periodically, and determines that the defrosting operation is necessary when the difference is equal to or greater than a predetermined value. Then, the command unit 43 completely disconnects the refrigerant switching valve 37 or cuts the branch pipe direction toward the evaporator (for example, the first evaporator) according to the determination of the determination unit 42, It is prevented from flowing into the corresponding first evaporator 35.

Next, the compressor 31 continues to operate for a predetermined time by the command unit 43. Then, the refrigerant remaining in the first evaporator (35) is sucked into the compressor (31), so that the refrigerant does not remain or remains in the first evaporator (35).

Next, the first defrost heater 353 operated by the command unit 43 is operated. And the compressor (31) is stopped by the command unit (43). However, since the refrigerant does not flow into the first evaporator 35, the compressor may be continued to operate and the cold air may be continuously supplied to the corresponding cooling chamber through the second evaporator 36.

Next, when the detected temperature of the evaporator detected by the temperature sensor 354 installed in the first evaporator 35 becomes lower than the set temperature by a certain value, the judging unit 42 of the microcomputer 4 judges that the defrosting It is judged that the operation is completed. Then, the command unit 43 stops power supply to the first defrost heater 353 to stop defrosting operation.

Next, the refrigerant switching valve 37 opens the branch pipe of the first evaporator 35 by the command unit 43 of the microcomputer 4, So that a cool air is generated in the air. The second evaporator can also perform the defrosting operation through the same process as the first evaporator.

In the case where the refrigerant switching valve 37 is a three-way valve, even when both the first evaporator 35 and the second evaporator 36 require defrosting operation, as in the above-described operation process, shall. In this case, it is preferable that the defrosting operation for the refrigerating side evaporator having a relatively short defrosting time is performed promptly, and then the defrosting operation is performed for the refrigerating chamber side evaporator having a relatively long defrosting time.

On the other hand, when the refrigerant switching valve 37 is a four-way valve and both the first evaporator 35 and the second evaporator 36 require defrosting operation, the four-way valve completely blocks the flow of the refrigerant, 1 defroster 25 and the second evaporator 26 at the same time. However, in this case, the refrigerant can not circulate in the refrigeration cycle apparatus, and oil shortage may occur in the compressor. Accordingly, in this case, it is preferable to provide an oil circulation unit at the inlet or the outlet of the compressor so that the oil can be forcedly circulated. For example, as shown in FIG. 6, an oil pump 38 may be installed at the inlet of the compressor 31 to pump the oil remaining in the evaporator or the branch pipe to the compressor. Alternatively, as shown in FIG. 7, It is preferable that the oil separator 39 is installed at the outlet of the compressor 31 to separate the oil from the refrigerant discharged from the compressor 31 and to carry it into the compressor 31 again.

In this way, the defrosting operation is performed in a state in which the refrigerant is not left in the evaporator, so that the defrosting operation time for the evaporator can be shortened, thereby preventing the internal load temperature from rising, thereby saving power consumption . In addition, the refrigerant in the evaporator is prevented from being heated and expanded during the defrosting operation, thereby preventing the suction loss in the compressor, thereby improving the efficiency of the refrigerator.

In the meantime, another embodiment of the criterion for determining whether defrosting is occurring in the defroster of the refrigerator according to the present invention is as follows.

That is, in the above-described embodiment, the temperature of the evaporator is detected to determine the evaporation point and the evaporation end point. However, in this embodiment, the defrosting operation for the evaporator is judged based on time .

To this end, the microcomputer 4 is provided with a timer (not shown) so that the defrosting operation can be performed periodically by checking the cooling operation time and defrosting operation time of the refrigerator. That is, it is preferable that the microcomputer 4 is inputted with the refrigerant switching valve 37 opening / closing time as well as the starting point of the refrigerating cycle device. In this case, it is effective that the timer is equipped with a function of resetting the detection time.

The microcomputer 4 may include an input unit 41, a determination unit 42, and a command unit 43 as described above. However, the input unit 41 and the determination unit 42 are different from the above-described embodiments in that the temperature is set as described above, and the operation time is input for comparison and determination. Other basic configurations and operation effects are similar to those of the above-described embodiments, and thus a detailed description thereof will be omitted.

Although not shown in the figure, whether or not the temperature sensor and the timer are installed together to determine whether the defrosting operation is necessary is determined through the temperature sensor, while the completion of defrosting operation may be determined using a timer.

1: refrigerator main body 2: refrigerator door
3: Refrigeration cycle device 4: Microcomputer
31: compressor 32: condenser
33, 34: expander 35, 36: evaporator
37: Refrigerant switch valve 38: Oil pump
39: Oil separator 41: Input part
42: Judgment section 43:
353: defrost heater

Claims (10)

1. A defrost apparatus for a refrigerator which defrosts by heating at least one evaporator connected to a compressor,
A valve is provided between the evaporator and the condenser for limiting the inflow of the refrigerant into the evaporator before starting the defrosting operation for the evaporator,
The valve being electrically connected to a control unit for controlling the operation of the compressor,
Wherein the control unit drives the compressor before starting the defrosting operation for the evaporator, and controls the operation of the compressor to recover the refrigerant to the compressor in the evaporator. delete The method according to claim 1,
Wherein the defrost heater is provided with a defrost heater and the defrost heater is electrically connected to the control unit so that the defrost heater is interlocked with the compressor and the valve. The method of claim 3,
Wherein the control unit is provided with a timer and controls the defrosting operation based on time. The method of claim 3,
Wherein the evaporator is provided with a temperature sensor and controls the defrosting operation based on the temperature. 6. The method according to any one of claims 1 to 5,
And an oil circulation unit for forcibly circulating oil is further provided at an inlet or an outlet of the compressor connected to the evaporator. A defrost operation for the evaporator is determined;
Closing the inlet side of the evaporator to block the inflow of the refrigerant;
Operating a compressor connected to the outlet of the evaporator to recover the refrigerant remaining in the evaporator to the compressor;
Heating the evaporator to perform defrosting;
Stopping heating of the evaporator; And
And opening the inlet side of the evaporator to allow the inflow of the refrigerant. 8. The method of claim 7,
And closing the inlet side of the evaporator, the method further comprising the step of inputting the closing timing into the timer. 9. The method of claim 8,
Further comprising the step of resetting the timer in the step of opening the inlet side of the evaporator. 8. The method of claim 7,
Wherein the step of heating the evaporator further comprises the step of measuring the temperature of the evaporator in real time and comparing the measured temperature with the set temperature.

Images