KR19990048872A - How to defrost the refrigerator - Google Patents

Abstract

The present invention stores the defrost heating time according to the outside temperature and the number of door opening and closing times during normal operation of the refrigerator in the memory of the microcomputer, and when the defrosting sensor of the refrigerator generates a characteristic defect having a constant resistance value corresponding to the low temperature, The purpose of the present invention is to provide a defrosting method of the refrigerator that improves the convenience of use of the refrigerator and resolves the complaints of consumers by allowing defrost heating to be performed according to the stored defrost heating time according to the outdoor temperature and the number of door opening and closing times. .

The present invention for this purpose, the step of recording and storing the outside temperature and the number of door opening and closing during normal operation of the refrigerator; Recording and storing a defrost heating time corresponding to the outside temperature and the number of door opening and closing times; Determining whether the defrost sensor has a characteristic defect having a constant resistance value regardless of ambient temperature change; And a defrosting step of performing defrost by heating the defrost heater according to the defrost heating time corresponding to the recorded outside air temperature and the number of door opening and closing times when the defrost sensor has a characteristic defect.

Description

How to defrost the refrigerator

The present invention relates to a method of defrosting a refrigerator. More specifically, the defrost heating time according to the outdoor temperature and the number of door opening and closing times during normal operation of the refrigerator is stored and stored in the memory of the microcomputer, and the defrosting sensor of the refrigerator corresponds to a low temperature. When deterioration of characteristic with resistance value occurs, defrost heating is performed as much as defrost heating time stored according to the outside temperature at the time of defrosting and the number of door opening and closing times to improve the convenience of use of the refrigerator and resolve consumer complaints. A method of defrosting a refrigerator.

As is well known, in the evaporator of a refrigerator, cooling is performed by the heat of evaporation which the liquid refrigerant takes from the surroundings when it evaporates. At this time, the frost is pinched by the freezing of moisture around the evaporator. In such a castle, it is necessary to remove the frost because it is a main factor that greatly reduces the evaporator efficiency. Therefore, the refrigerator is provided with a defrost heater which is electrically heated to melt frost attached to the evaporator, and means for appropriately controlling the defrost heater.

1 schematically shows a hardware circuit for defrosting in a typical refrigerator. Referring to FIG. 1, reference numeral 1 is a defrost heater installed in an evaporator, 2 is a relay for intermitting a power applied to the defrost heater, 3 is overheating of the defrost heater 1 or an overcurrent to the defrost heater. The temperature fuse to prevent the failure of the heater 1 by the 10, the microcomputer for the defrost control of the refrigerator and the refrigerator, 100 is a defrost sensor installed in the evaporator to sense the temperature, reference numeral IV is the microcomputer of the Inverter to excite the coil of the relay (2) according to the control to turn the contact on / off, R1 is a voltage distribution resistor that is connected in series with the defrost sensor 100 to distribute the voltage, R2 is applied to the microcomputer 10 A current limiting resistor, C, which limits the current, is a capacitor that removes noise that can be applied to the microcomputer 10. Here, the defrost sensor 100 is a thermistor having a property that the resistance of the defrosting sensor 100 is high when the temperature is high, and the resistance of the defrosting sensor is large when the temperature is low. In FIG. 1, there is one defrost sensor 100, but when there are two evaporators, for example, two defrost sensors are installed when the evaporator for a refrigerator compartment and the evaporator for a freezer compartment are installed independently. Will be self explanatory. The same applies to the following.

In the refrigerator defroster configured as described above, since the resistance value of the defrost sensor 100 varies according to temperature, the signal input to the microcomputer 10 also changes. The microcomputer 10 generates heat of the heater 1 according to a preset defrosting condition to perform defrosting of the evaporator. That is, when the above defrosting condition is reached, the microcomputer 10 applies a high signal to the inverter IV to excite the coil of the relay 2 so that its contact is turned on. When the relay 2 contact is turned on, power is applied to the heater 1. When power is applied to the heater 1, the heater 1 generates heat, and defrost is generated by the heat of heating. During the defrosting, the temperature of the heater 1 increases, which is detected by the defrost sensor 100 and input to the microcomputer 10. When the heating temperature of the heater 1 sensed by the defrost sensor 100 is greater than or equal to a predetermined temperature, the microcomputer 10 terminates the defrosting by preventing power from being applied to the heater 1.

In the defrosting operation of the refrigerator as described above, the resistance value of the sensor is not changed, corresponding to the ambient temperature, rather than an open or short failure of the defrost sensor 100, and the constant resistance value is always changed. Defective operation of the sensor when it occurs, defrosting operation is not made properly, which will be described as follows.

That is, when the defrost sensor 100 always has a resistance value corresponding to a low temperature irrespective of the ambient temperature, the microcomputer 10 generates the heater 1 in accordance with the defrost cycle to defrost the evaporator. However, since the defrosting sensor 100 is fixed at a resistance corresponding to a low temperature even though the heater 1 continues to generate heat and the evaporator temperature is considerably high, the microcomputer 10 has significantly increased the temperature of the evaporator as described above. Since the state is not recognized, the heater 1 is continuously heated. The exothermic state of the heater 1 lasts for about 2 to 8 hours when the temperature fuse 3 is disconnected. This also raises the temperature in the refrigerator.

As described above, when the defrost sensor 100 always has a resistance value corresponding to a low temperature, a method of checking the rising width of the internal temperature to terminate defrost heating is applied, which is according to the refrigerator load. There is a problem of raising the internal temperature higher than the temperature. This problem is also a strong claim for consumers.

The present invention was created in order to solve the above problems, and the defrost heating time according to the outside temperature and the number of door opening and closing times in normal operation is stored and stored in the memory of the microcomputer, and the defrost sensor of the refrigerator corresponding to a low temperature A refrigerator that improves the convenience of use of the refrigerator and resolves consumer complaints by allowing defrost heating to be performed as much as the stored defrost heating time according to the outside temperature at the time of defrosting and the number of door opening and closing times when defrosting occurs. The purpose is to provide a defrosting method.

1 is a hardware circuit diagram of a refrigerator for implementing a defrosting method of a conventional refrigerator;

2 is a hardware circuit diagram of a refrigerator for implementing a defrosting method of the refrigerator according to the present invention;

3 and 4 are a flow chart of a defrosting method of the refrigerator according to the present invention.

<Description of the symbols for the main parts of the drawings>

1: defrost heater 3: temperature fuse

10 microcomputer 100 defrost sensor

110: outside temperature sensor 120: door switch

Defrosting method of the refrigerator according to the present invention to achieve the above object,

In the defrosting method of the refrigerator,

Measuring and storing the outside air temperature and the number of door opening and closing times during normal defrosting operation of the refrigerator;

Recording and storing a defrost heating time corresponding to the outside temperature and the number of door opening and closing times;

Determining whether the defrost sensor has a characteristic defect having a constant resistance value regardless of ambient temperature change;

If the defrost sensor is a characteristic defect, the step of heating the defrost heater according to the defrost heating time corresponding to the recorded outside air temperature and the number of door opening and closing;

In a preferred embodiment of the present invention, the deficient characteristic of the defrost sensor is a state that will always have a resistance value corresponding to a low temperature regardless of the ambient temperature.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the defrosting method of the refrigerator according to the present invention. For convenience of description, the same reference numerals are used for constituent members that have the same function as those used in the prior art.

2 is a hardware circuit diagram of a general refrigerator for implementing the defrosting method of the refrigerator according to the present invention, Figures 3 and 4 are a flow chart of the defrosting method of the refrigerator of the present invention. It will be apparent to those skilled in the art that the flowchart algorithm of the present invention defrosting method shown in FIGS. 3 and 4 can be programmed and stored in the microcomputer 10. It will be apparent to those skilled in the art that when the flowchart algorithm of the method of the present invention is performed by the microcomputer 10, the flowchart algorithm of FIGS. 3 and 4 will be programmed and executed as a sub-routine.

Referring to FIG. 2, in order to implement the defrosting method of the refrigerator of the present invention, the microcomputer 10 further receives a corresponding signal from the outside temperature sensor 110 and the door switch 120.

Referring to FIG. 3, in the defrosting method of the refrigerator of the present invention, it is determined whether the refrigerator performs normal defrosting operation, and measuring and storing the outside temperature and the number of door opening and closing at this time, and storing the same in the memory of the microcomputer 10 (S1). (S2) is provided. The measurement of the outside air temperature and the number of door opening and closing is achieved by the outside air temperature sensor 110 and the door switch 120. In addition, the defrosting method of the present invention includes a step S3 of recording and storing the defrost heating time T corresponding to the outside temperature and the number of door opening and closing times in the memory of the microcomputer 10 after step S2.

In the defrosting method of the present invention, it is determined whether the defrosting condition (S10), and if the defrosting condition, the defrosting sensor 100 determines whether there is always a characteristic defect having a constant resistance value regardless of ambient temperature change (S11). And, if the defrost sensor 100 is a characteristic failure, select the defrost heating time (T) corresponding to the stored outside temperature and the number of door opening and closing in step S3 and generates the defrost heater (1) according to the selected defrost heating time And defrosting (S12) (S13). In step S13, a step of generating (heating) the heater 1 for defrosting (S14), determining whether the heating of the heater 1 is performed for the predetermined time (S15), and the heater 1 If the heating has been made for the predetermined time, and the step (S16) for terminating the defrost heating. Defect characteristic of the defrost sensor 100 in step S11 is to be in a state that always has a resistance value corresponding to a low temperature regardless of the ambient temperature (hereinafter, abbreviated as "low temperature characteristic defect"), the defrost sensor 100 is The high signal (substantially 5 volts) or the low signal (substantially 0 volts) is input to the microcomputer 10 due to disconnection or short circuit.

The operation of the defrosting method of the present invention refrigerator configured as described above will be described with reference to FIGS. 2 to 4. It will be apparent to those skilled in the art that the illustrated flow diagram algorithm of the defrosting method of the present invention can be programmed and stored in the microcomputer 20.

First, when the defrost sensor 1 is normal, the microcomputer 10 determines whether normal defrosting operation is performed according to the defrosting condition (S1). At this time, the microcomputer 10 measures the outside temperature and the number of door opening and closing until the defrost condition is achieved.

If the normal defrosting operation is performed in step S1, the microcomputer 10 stores the measured outside temperature and the number of door opening and closing times in its own memory (S2), and generates heat of the heater 1 according to the defrosting condition. (T) is also stored and stored in the memory (S3). While the defrost sensor 100 is normal and normal defrosting operation is performed, the microcomputer 10 repeats steps S1, S2, and S3.

When the steps S1, S2, and S3 are repeatedly performed, the outside air temperature, the number of door opening and closing times, and the corresponding defrost heating time T are stored and stored in the memory of the microcomputer 10 as shown in Table 1.

Outside temperature (℃) Door open / close frequency (per hour) 33 or more 32-18 17 or less 5 or more times 26 minutes 20 minutes 14 minutes 2-4 times 24 minutes 18 minutes 12 minutes 1 time or less 22 minutes 16 minutes 10 minutes

Defrost heating time T of Table 1 is set by the step S20 of FIG. 4, the step S20 is also achieved by a general refrigerator defrosting method. That is, in the normal defrosting operation, if the temperature detected by the defrosting sensor 1 is a predetermined temperature, for example, 0 ° C. or less (S21), defrost heating is performed (S22), otherwise it is not necessary to defrost heating. Therefore, the microcomputer 10 performs another operation control of the refrigerator. During the defrost heating in step S22, the microcomputer 10 determines whether the detected temperature of the defrost sensor is above a predetermined set temperature (for example, 10 ° C.), and if the detected temperature is equal to or greater than the set temperature, this indicates that sufficient defrost is obtained. Defrost heating is determined to be determined, otherwise defrost heating is continued (S23) (S24).

As described above, the defrost heating time T according to the outside temperature and the number of door opening and closing times as shown in Table 1 are stored in the memory of the microcomputer 10 through the normal defrosting operation in the normal state of the defrost sensor 100 as described above. If this is established, the microcomputer 10 determines whether the defrost sensor 100 is a characteristic defect or substantially a low temperature characteristic defect (S10) (S11).

If the defrost sensor 100 is not in the characteristic defect state in step S11, the microcomputer 10 performs the step S20 normally, as described above, and if the defrost sensor 100 is the low temperature characteristic defect, the microcomputer 10 is Defrost heating is performed by the defrost heating time T corresponding to the outside air temperature and the number of door opening and closing times until the defrosting condition is established, thereby preventing defrost heating until the temperature fuse 3 is disconnected as in the related art.

When the above description is given by way of example, if the defrosting condition is established, and the defrosting sensor 100 has a low temperature characteristic defect (S10) (S11), the microcomputer 10 will keep the outside temperature and the door until the defrosting condition is established. Select defrost heating time (T) corresponding to the number of opening and closing. That is, when the outside temperature and the number of door opening and closing times until the defrosting condition is established are 32 ° C.-18 ° C., two times four times as shown in Table 1, the microcomputer 10 sets the defrost heating time T. 18 minutes is selected so that defrost heating is performed (S12) (S13). While the defrost heating is performed, the microcomputer 10 checks whether the defrost heating time has elapsed 18 minutes, and if 18 minutes has elapsed, the defrost heating is terminated. Otherwise, the microcomputer 10 continues defrost heating until 18 minutes have elapsed (S14) ( S15) (S16).

That is, in the present invention, when the defrosting sensor 100 has a low temperature characteristic defect, the defrosting sensor 100 performs defrosting by the defrost heating time corresponding to the outside temperature and the door opening / closing frequency until the low temperature characteristic defect occurs. The problem of defrost heating until the fuse 3 is disconnected is solved.

As described above, the defrosting method of the refrigerator according to the present invention stores the defrost heating time according to the outside temperature and the number of door opening and closing operations during normal operation in the memory of the microcomputer, and then when the low temperature characteristic defect occurs in the defrost sensor of the refrigerator, Defrost heating as much as the defrost heating time stored in accordance with the outside air temperature and the number of door opening and closing at is made to improve the convenience of use of the refrigerator and provides an advantage to resolve the complaints of consumers.

Claims (3)

In the defrosting method of the refrigerator, Measuring and storing the outside air temperature and the number of door opening and closing times during normal operation of the refrigerator; Recording and storing a defrost heating time corresponding to the outside temperature and the number of door opening and closing times; Determining whether the defrost sensor has a characteristic defect having a constant resistance value regardless of ambient temperature change; Defrosting method of the refrigerator comprising: a defrosting step of performing a defrost by heating the defrost heater according to the defrost heating time corresponding to the recorded outside air temperature and the number of door opening and closing times if the defrost sensor is poor characteristics; . 2. The method of claim 1, wherein the deficient characteristic of the defrost sensor has a resistance value corresponding to a low temperature at all times regardless of the ambient temperature. According to claim 1, The defrosting step, Selecting the defrost heating time, generating the heater for defrosting, determining whether the heater generates heat during the selected heating time, and generating heat of the heater during the selected heating time. If it is done, the defrosting method of the refrigerator characterized in that it comprises the step of terminating the defrost heating.