KR19990043745A - Defrost control method in the refrigerator - Google Patents

Abstract

The present invention relates to a defrosting control method in a refrigerator to remove the frost on the surface of the evaporator while minimizing the temperature rise of the refrigerating chamber during defrosting, the compressor is driven on the refrigerator for a predetermined time when switching to the defrost mode Controlling the fan for discharging the cold air in response to the refrigerating chamber temperature, turning off the compressor and driving on the defrost heater installed inside the evaporator after a predetermined time elapses, and the internal temperature of the evaporator is the first reference temperature. Controlling the fan until abnormality and stopping the normal control of the fan when the evaporator internal temperature is above the first reference temperature and driving off the defrost heater when the evaporator internal temperature is above the second reference temperature; In the refrigerator, a fan for discharging cold air from the refrigerator to the refrigerating compartment or, optionally, the freezing compartment. When the evaporator surface temperature is below the first reference temperature (for example, 2 ° C.), which is an appropriate temperature zone inside the refrigerating compartment, the fan is normally controlled to prevent weak cooling of the refrigerating compartment and the freezing compartment. For example, since about 2 ° C. and the cold air around the evaporator (eg, −27 ° C.) before driving the heater are mixed by driving the fan, the heat generation time of the heater may be shortened to reduce power consumption during defrosting.

Description

Defrost control method in the refrigerator

The present invention relates to a method for controlling defrost in a refrigerator, and more particularly, to a method for controlling defrost in a refrigerator to prevent defrost on the surface of an evaporator while minimizing a temperature rise in the refrigerating compartment.

In general, a refrigeration cycle of a refrigerator includes a compressor for compressing and outputting a low-temperature, low-pressure gaseous refrigerant, and a condenser and a condenser for cooling and condensing the high-temperature, high-pressure gaseous refrigerant from the compressor by external air. It is circulated through a capillary tube for depressurizing and outputting a refrigerant in a high pressure liquid state and an evaporator for absorbing and cooling heat by evaporating to a low temperature in a low pressure state. The fan-cooling refrigerator includes a fan for discharging cold air, and discharges cold air around the evaporator into the freezer compartment and the refrigerating compartment to cool the inside of the refrigerator, and performs temperature control as a driving / stop control of the fan and the compressor. .

On the other hand, among these fan-cooling refrigerators, which convectively cool the air around the evaporator by a fan, the refrigerator that controls the temperature centered on the temperature of the refrigerator compartment has one fan in the freezer compartment and detects it in the refrigerator compartment. In order to liquefy a fan and a gaseous refrigerant that discharge cold air based on the set temperature, a compressor for converting a low pressure low temperature refrigerant gas into a high pressure high temperature refrigerant gas is driven on / off to control the cold air around the evaporator in the freezer compartment and the refrigerator compartment. To keep the refrigerator at the proper temperature.

In other words, if the detected temperature in the refrigerating compartment is above the predetermined upper limit temperature, the fan and the compressor are simultaneously driven on to cool the freezer compartment and the refrigerating compartment, and if the detected temperature in the refrigerating compartment is lower than the preset lower limit temperature, the fan and compressor are The drive is stopped at the same time to stop cooling.

On the other hand, moisture in the air inside the refrigerator and water that evaporates from the food freezes, causing frost on the surface of the evaporator. If not, there is a lot of adhesion to the evaporator. The low heat transfer rate results in lower cooling efficiency and higher compressor operation rate, resulting in increased power consumption. Therefore, defrosting is necessary to keep the refrigerator's cooling function at its best at all times.

Therefore, when a defrost heater is conventionally used to perform defrosting of the evaporator, a defrost heater is installed inside the evaporator to energize the defrost heater during defrosting to remove defrost of the evaporator.

However, there has been a problem in that the temperature of the refrigerating chamber is increased while the defrost heater is driven by keeping the fan discharging cold air into the refrigerating chamber when the defrost heater is driven.

An object of the present invention is to selectively control the driving of the fan to discharge the cold air to the refrigerating chamber when the defrost heater is removed when the evaporator surface defrosting of the refrigerator to prevent weak cooling of the refrigerating chamber and reduce the power consumption by reducing the drive time of the defrost heater. It is to provide a defrost control method in a refrigerator.

Defrost control method in the refrigerator according to the present invention, a method for removing the frost attached to the refrigerator evaporator, when switching to the defrost mode to drive a compressor for a predetermined time and discharge the cold air to the refrigerator compartment corresponding to the refrigerator compartment temperature Controlling normally, turning off the compressor after a predetermined time, driving on the defrost heater installed inside the evaporator, controlling the fan normally until the evaporator internal temperature is equal to or greater than the first reference temperature, and Stopping the normal control of the fan when the temperature is above the first reference temperature and driving off the defrost heater when the evaporator internal temperature is above the second reference temperature.

1 is a schematic block diagram of a refrigerator employed according to a preferred embodiment of the present invention.

2 is a flowchart illustrating a defrost control process in a refrigerator according to a preferred embodiment of the present invention.

<Explanation of symbols for main parts of the drawings>

10,70: first and second temperature detection unit 20: microcomputer

30: fan drive unit 40: fan

50: compressor drive unit 60: compressor

80: heater driving unit 90: heater

The above objects and various advantages of the present invention will become more apparent from the preferred embodiments of the invention described below with reference to the accompanying drawings by those skilled in the art.

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

1 is a schematic block diagram of a refrigerator employed according to the present invention, the first and second temperature detectors 10 and 70, the microcomputer 20, the fan driver 30, the fan 40, and the compressor driver 50. ), A compressor 60, a heater driver 80, and a heater 90.

In this configuration, the first temperature detection unit 10 is installed at a predetermined position in the refrigerating chamber to detect the room temperature of the refrigerating chamber and apply the detection signal to an A / D (Analog to Digital) port of the microcomputer 20 which will be described later. .

In addition, the microcomputer 20 controls the compressor 60 to be driven on for a predetermined time when switching to the defrost mode, and normally controls the fan 40. That is, the fan 40 which will be described later when the refrigerating chamber detection temperature applied to the A / D port through the first temperature detecting unit 10 and converted into a digital signal is equal to or lower than an appropriate lower limit temperature (for example, 2 ° C.) of the predetermined refrigerating chamber. Drive stop control, and if the detected temperature is equal to or higher than a predetermined upper limit temperature (for example, 2.35 ° C) of the predetermined refrigerating chamber, the fan 40 is driven on and controlled to switch to the pre-cool mode.

In addition, after performing the above-described precooling mode for a predetermined time, the microcomputer 20 drives the heater 90 to turn on the first reference temperature at which the evaporator detection temperature from the second temperature detecting unit 70 is preset. For example, the fan 40 is normally controlled until the temperature is 2 ° C or higher, and then the normal control of the fan 40 is stopped, and the evaporator detection temperature is equal to or higher than the preset second reference temperature (eg, 10 ° C). When the heater 90 is turned off, the heater 90 is switched to the idle mode for a predetermined time and the defrost mode is terminated.

On the other hand, the fan driver 30 outputs a predetermined drive signal to the fan 40 based on the control from the microcomputer 20 using a drive element, a relay, or the like, and the fan 40 is connected to the fan driver 30 from the fan driver 30. Driven based on the drive signal, the cold air around the evaporator (not shown) is discharged to the freezing compartment and the refrigerating compartment.

In addition, the compressor driving unit 50 outputs a predetermined driving signal to the compressor 60 based on the product from the microcomputer 20 by using a driving element, a relay, or the like, and the compressor 60 is in the refrigeration cycle described above. As a preparation step for re-liquefying the vaporized refrigerant to be reused, the refrigerant gas of low temperature and low pressure from the evaporator, not shown, is compressed and converted into a refrigerant gas of high temperature and high pressure, and outputted to a condenser, not shown.

On the other hand, the second temperature detector 70 is installed inside the evaporator detects the surface temperature of the evaporator and applies it to the A / D port of the microcomputer 20.

The heater driver 80 outputs a predetermined driving signal to the heater 90 based on the control of the microcomputer 20 using a driving element and a relay, and the heater 90 removes frost attached to the evaporator. As a defrost heater for heating, it is mounted on an evaporator to generate heat based on a drive signal from the heater driver 80 to melt and remove frost attached to the evaporator.

Next, the defrost control process in the refrigerator according to the preferred embodiment of the present invention including the above-described component will be described in detail with reference to the flowchart of FIG. 2.

First, when the microcomputer 20 is switched to the defrost mode (step 200), the compressor 60 is continuously driven on for a predetermined time, and the fan 40 is normally controlled in response to the temperature in the refrigerating chamber as described above. The precool mode is switched to (step 202).

In detail, the compressor 60 is continuously driven on irrespective of the temperature of the refrigerating chamber, and the appropriate refrigerating chamber temperature detected based on the first temperature detection unit 10 has a predetermined lower limit temperature (for example, 2 ° C.). The fan 40 is driven off, and when the detected refrigerator compartment temperature is higher than a predetermined upper limit temperature (for example, 2.35 ° C), the fan 40 is driven on to control the fan 40 normally. .

In the precool mode, the refrigerator is cooled as much as possible before entering the defrost mode, that is, before the heater 90 for defrosting is operated in order to prevent the weak cooling of the refrigerator to the maximum as the temperature of the evaporator increases due to the heater during defrosting. It is for.

Next, the microcomputer 20 performs the precool mode for a predetermined time and then stops driving the compressor 60 and drives the heater 90 for defrosting on (step 204).

Then, the heater 90 is energized based on the drive signal of the heater driver 80 to start the heat generation, and thus the temperature of the evaporator rises to remove the frost attached to the evaporator.

On the other hand, after the heater 90 is driven, the microcomputer 20 recognizes the evaporator surface (internal) temperature based on the second temperature detector 70, and the detected evaporator surface temperature is a preset second reference temperature (eg, 2 ° C) or higher (step 206).

At this time, if the detected evaporator surface temperature is lower than the second reference temperature, defrost is performed while controlling the fan 40 normally to prevent the temperature of the refrigerating chamber from rising as much as possible (step 208).

On the other hand, when the evaporator surface temperature detected in step 206 described above becomes equal to or greater than the second reference temperature, normal control of the fan 40 is stopped (step 210).

This is because, when the evaporator surface temperature is equal to or higher than the second reference temperature, it is difficult to obtain a cooling effect even when the fan 40 is driven, but rather the refrigerator compartment temperature is increased.

Next, the microcomputer 20 determines whether the detected evaporator surface temperature is equal to or greater than the second preset reference temperature (eg, 10 ° C.) (step 212).

At this time, when the detected evaporator surface temperature is lower than the second reference temperature, defrosting is continued by driving the heater 90, and when the detected evaporator surface temperature is higher than the second reference temperature, frost attached to the evaporator is removed. It recognizes and stops driving of the heater 90 for defrosting (step 214).

That is, when the surface temperature of the evaporator is lower than the first criterion when driving the heater 90 for defrosting, the fan 40 is normally controlled so that the weak cooling phenomenon of the refrigerating compartment or the freezing compartment (the refrigerator controlling the temperature in the center of the refrigerating compartment) is maximized. It is to remove the frost attached to the evaporator while preventing.

On the other hand, it will be understood by those skilled in the art that various changes and modifications can be made without departing from the spirit of the present invention.

As described above, according to the present invention, the fan 40 for discharging cold air from the refrigerator to the refrigerating compartment or optionally the freezing compartment at the time of defrosting has a first reference temperature (eg, 2 ° C.) at which the evaporator surface temperature is an appropriate temperature band inside the refrigerating compartment. ), The fan 40 is normally controlled to prevent weak cooling of the refrigerating compartment and the freezing compartment, and also to prevent cold air in the refrigerating compartment (for example, about 2 ° C.) and cold air around the evaporator before driving the heater 90. For example, since −27 ° C.) is mixed by the driving of the fan 40, the heat generation time of the heater 90 may be shortened to reduce power consumption during defrosting.

Claims (1)

A method of removing frost attached to a refrigerator evaporator, Normally controlling the fan 40 for driving the compressor 60 for a predetermined time when switching to the defrost mode and discharging cold air into the refrigerating chamber in response to the refrigerating chamber temperature; Turning off the driving of the compressor (60) and driving on a heater (90) installed in the evaporator after the predetermined time elapses; Normally controlling the fan 40 until the detected evaporator internal temperature is equal to or greater than the first preset reference temperature. If the detected evaporator internal temperature is equal to or greater than the first reference temperature, the normal control of the fan 40 is stopped. Steps; Driving off the heater (90) if the detected evaporator internal temperature is equal to or greater than a second preset reference temperature.