JPH07120130A - Refrigerator - Google Patents

Abstract

PURPOSE:To prevent liquid compression due to flow of liquid refrigerant from a compressor to an evaporator at the time of starting the compressor after defrosting of a refrigerant is finished. CONSTITUTION:The refrigerator comprises a body 1 having a cold storage chamber 3 and a refrigerating chamber 4 formed by dividing its interior by a partition 2 by installing a refrigerating cycle in which a compressor 9, a condenser 10, a capillary tube 11 and an evaporator 12 are sequentially annularly connected, and an indoor fan 16 for heat exchanging the evaporator 12 with the air in the body 1. Further, the refrigerator comprises a defrosting heater 14 installed near an air suction side of the evaporator 12, defrost end sensing means for sensing defrost end of the evaporator 12, and defrost control means for starting the fan 16 simultaneously upon stopping energization of the heater 14 according to an output of the sensing means, starting the compressor 9 after a predetermined time and starting an ordinary operation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerator, and more particularly, to defrost control of an evaporator.

[0002]

2. Description of the Related Art A conventional refrigerator is disclosed in JP-A-64-6758.
It has a configuration known from Japanese Patent Publication No. Less than,
The configuration of a conventional refrigerator will be described with reference to FIG.

Reference numeral 1 denotes a body of a refrigerator, which is partitioned by a partition wall 2 into a refrigerating room 3 and a freezing room 4. Further, a refrigerating compartment door 5 and a freezing compartment door 6 are individually installed in the refrigerating compartment 3 and the freezing compartment 4, respectively. A machine room 7 is located in the lower back of the main body 1.
Is installed. A cooling chamber 8 which is separated from the freezing chamber 4 is installed on the back side of the freezing chamber 4. A compressor 9 is installed in the machine room 7, and a condenser 10, a capillary tube 11, an evaporator 12 installed in the cooling room 8 and a suction pipe 13 are sequentially connected in an annular shape to form a cooling system. The capillary tube 11 and the suction pipe 1
3 are installed in close contact with each other by heat exchange, for example, by soldering. A defrosting heater 14 is installed near the evaporator 12 and starts defrosting.
A defrost detecting means 15 for detecting the end is installed. Also,
A blow-out air passage 17 and a suction air passage 1 for communicating the air cooled by the evaporator 12 to the refrigerating compartment 3 and the freezing compartment 4, which communicates the inside fan 16 with the refrigerating compartment 3, and the freezing compartment 4 and the cooling compartment 8.
Have eight.

Further, inside the freezing compartment 4, a freezing compartment temperature adjusting means 19 for controlling the temperature of the freezing compartment 4 by stopping the operation of the compressor 9 is installed. At the opening 20 of the refrigerating compartment 3 of the blowing air passage 17, a refrigerating compartment temperature control means 21 for controlling the temperature inside the refrigerating compartment 3 is installed.

Next, the operation of the above configuration will be described with reference to FIG. While operating the compressor 9, the internal fan 1
6 is operated, and the cooling system starts cooling the refrigerating chamber 3 and the freezing chamber 4.

The high-temperature and high-pressure refrigerant discharged from the compressor 4 exchanges heat with the outside air in the condenser 10 to be condensed and liquefied, and then flows into the capillary tube 11. Capillary tube 1
In 1, the refrigerant is decompressed and evaporated in the evaporator 12, and the internal fan 16 exchanges heat with the air in the refrigerator compartment 3 and the freezer compartment 4. Here, the evaporated and vaporized refrigerant directly passes through the suction pipe 13 and returns to the compressor 9. At this time, since the capillary tube 11 and the suction pipe 13 are arranged in a heat exchange manner, the vaporized low-temperature gas refrigerant in the suction pipe and the liquefied high-temperature liquid refrigerant in the capillary tube 11 are By exchanging heat, the enthalpy of the liquid refrigerant decreases and increases in the supercooling direction, and the gas refrigerant decreases and increases in the overheating direction. This increases the refrigeration effect and improves the refrigeration capacity of the cooling system.

The temperature of the refrigerating compartment 3 is a predetermined temperature (for example, 3
C.), the refrigerating compartment temperature control means 21 closes the opening of the blowing air passage 17 in the refrigerating compartment 3 to prevent the air cooled in the cooling compartment 8 from flowing into the refrigerating compartment 3.

Further, when the temperature of the freezer compartment 4 reaches a predetermined temperature (for example, -19 ° C.), the freezer compartment temperature control means 19
Stops the compressor 9 and stops cooling. Then, the temperature of the freezer compartment 4 rises and reaches a second predetermined temperature (for example,-).
(17 ° C.), the freezer compartment temperature control means 19 restarts the compressor 9 and starts cooling.

By performing the operation, the evaporator 12 is gradually defrosted, and when the predetermined amount of frost is reached, the defrosting detection means 15
Detects frost formation and starts defrosting operation. With the start of the defrosting operation, the compressor 9 and the internal fan 16 are stopped, and at the same time, the energization of the defrosting heater 14 is started. The heat generated by the defrosting heater 14 heats the evaporator 12 to melt the frost.

When the defrosting detecting means 15 detects that the frost has been melted, the defrosting heater 14 is deenergized, and after a predetermined time,
The operation of the compressor 9 and the internal fan 16 is started, and then the cooling of the refrigerating room 3 and the freezing room 4 is started again.

[0011]

However, in the above-mentioned conventional configuration, the refrigerant in the evaporator 12 at the end of defrosting is re-condensed in the evaporator 12 after the energization of the defrosting heater is completed, and then the compressor is discharged. At the time of starting 9, the recondensed liquid refrigerant is sucked into the compressor 9 without evaporating, the compressor 9 performs liquid compression, and the compressor 9 is damaged.
Was a major issue in terms of reliability.

[0012]

Therefore, the refrigerator of the present invention is provided with a refrigeration cycle in which a compressor, a condenser, a capillary tube, and an evaporator are sequentially connected in an annular shape, and the inside is divided by a partition wall. A formed body of a refrigerator provided with a refrigerating room and a freezing room, an internal fan for exchanging heat between the evaporator and air in the refrigerator main body, a heater for defrosting the evaporator, and a defrosting end of the evaporator Defrosting end detecting means for detecting the, and the operation of the internal fan is started at the same time when the defrosting heater is stopped by the output of the defrosting ending detection means,
The defrosting control means starts the compressor after a predetermined time and starts the normal operation.

Further, an air passage for circulating the air cooled by the evaporator to the refrigerating compartment and the freezing compartment, a freezing compartment of the air passage, a freezer compartment damper provided at an opening of the refrigerating compartment, a refrigerating compartment damper, and an evaporator. Cooler temperature detecting means provided near the air outlet of the refrigerator, freezing room temperature detecting means provided in the freezing room, and a freezer compartment damper for opening and closing the freezing room damper by the outputs of the cold air temperature detecting means and the freezing room temperature detecting means. Control means installed.

Further, after the defrosting is completed, a defrosting heater control means for repeating energization and de-energization of the defrosting heater at a predetermined cycle is provided until the compressor is activated.

[0015]

With the above structure, the refrigerator according to the present invention operates only the internal fan after the defrosting, and heat-exchanges the air in the refrigerating room and the freezing room with the refrigerant in the evaporator. Prevented recondensation of the refrigerant. Furthermore, a freezer compartment damper is provided at the opening of the blowing air path to the freezer compartment, and after defrosting is completed, the circulation of the air to the freezer compartment is closed so that only the air in the refrigerating compartment with a higher temperature is provided. By exchanging heat, the refrigerant in the evaporator was prevented from being recondensed and the temperature inside the freezing chamber was prevented from rising.

Further, after the defrosting is finished, the defrosting heater is energized at a predetermined cycle to prevent the recondensation of the refrigerant in the evaporator.

By these actions, the amount of liquid refrigerant sucked from the evaporator to the compressor at the time of starting the compressor is significantly reduced,
The risk of liquid compression is very small.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. 1 and 2, but the same components as those of the prior art will be designated by the same reference numerals and detailed description thereof will be omitted.

Reference numeral 22 is a defrost control means, 23 is a defrost end detection means, and 24 is a timer. The defrost control means is 22
Is input to the defrost detection means 15, the defrost end detection means 23,
Each output of the timer 24 is provided, and as an output, the compressor 9,
It has a defrosting heater 14 and an internal fan 16. The defrosting completion detection means 23 is installed in the evaporator 12.

Next, the operation will be described with reference to FIGS. The frost formation on the evaporator 12 progresses, and the defrost detection means 15
However, when frost is detected (STEP 1), this output causes the defrost control means 22 to cause the compressor 9 and the internal fan 1 to operate.
6 is stopped, the defrosting heater 14 is energized to start defrosting (STEP 2).

The evaporator 1 is heated by the heat generated by the defrosting heater 14.
2 The frost adhering to the surface is radiated from the defrosting heater, convection of air in the vicinity, and heat transfer by evaporation and condensation of the internal refrigerant heated in the evaporator 14 near the defrosting heater 14 , Thaw.

As a result, the frost on the surface of the evaporator 12 is completely melted. At this time, the defrosting completion detecting means 23 detects the completion of defrosting and outputs a signal to the defrosting controlling means 22.

Upon receipt of this signal, the defrost control means 22
At the same time when the power supply to the defrosting heater 14 is stopped, the operation of the internal fan 16 and the integration of the timer 24 are started (S
TEP3). As a result, air begins to circulate in the freezer compartment 4 and the refrigerator compartment 3. At this time, the refrigerator compartment temperature control means 21
Since the temperature of the refrigerating compartment 3 is rising due to a long stop due to the defrosting operation, the opening of the blowing air passage 17 in the refrigerating compartment 3 is opened. no problem.

As a result, the refrigerant in the evaporator 12 does not condense due to the forced convection heat exchange with the air in the cold storage and cannot exist in the evaporator 12 as a supercooled liquid, and in addition, it does not exist. Evaporation is also promoted in the phase part.

The timer 24 integrates the time, and the predetermined time T
When the second has passed, the timer 24 outputs a signal. In response to this signal, the defrost control means 22 starts the operation of the compressor 9 and the cooling operation (STEP 4).

Next, a second embodiment will be described with reference to FIGS. Reference numeral 25 denotes a freezer compartment damper installed at the opening of the freezer compartment of the blowing air passage 17, and 26 denotes the blowing air passage 17
, A refrigerating compartment damper installed at the refrigerating compartment opening of the refrigerating compartment, and 27 a cold air temperature detecting means installed near the air outlet of the evaporator 12,
28 is a freezing room temperature detecting means provided in the freezing room 4, 29 is a refrigerating room temperature detecting means installed in the refrigerating room 3, 30 is a cold air temperature detecting means 27, a freezing room temperature detecting means 28, and a defrost control means. It is a freezer compartment damper control means for opening and closing the freezer compartment damper 25 by the output of 22.

Next, the operation will be described with reference to FIGS. The frost formation on the evaporator 12 progresses, and the defrost detecting means 15
When frost formation is detected (STEP 1), this output causes the defrost control means 22 to output a defrost start signal to the freezer compartment damper control means 30 and to stop the compressor 9 and the internal fan 16 as well. , Energize the defrosting heater 14,
Defrosting is started (STEP 2). At this time, the temperature Ter of the cooling chamber 8 rises due to the energization of the defrosting heater 14. Then, from the outputs of the cold air temperature detecting means 27 and the freezing room temperature detecting means 28, the cooling room 8 is lower than the temperature Tf of the freezing room 4.
The freezer compartment damper control means 30 detects that the temperature Ter has risen (STEP 3) and closes the freezer compartment damper 25 (STEP 4).

Due to the heat generated by the defrosting heater 14, the evaporator 1
2 The frost adhering to the surface is radiated from the defrosting heater, convection of air in the vicinity, and heat transfer by evaporation and condensation of the internal refrigerant heated in the evaporator 14 near the defrosting heater 14 , Thaw.

As a result, the frost on the surface of the evaporator 12 is completely melted. At this time, the defrosting completion detecting means 23 detects the completion of defrosting and outputs a signal to the defrosting controlling means 22 (STEP).
5).

Upon receiving this signal, the defrost control means 22
The energization of the defrosting heater 14 is stopped, and at the same time, the operation of the internal fan 16 and the addition of the timer 24 are started. At this time, the freezer compartment damper 25 is in the closed state, so that air begins to circulate in the refrigerating compartment 3. At this time,
Since the temperature Tp of the refrigerating room 3 has risen due to the refrigerating room damper 26 being stopped for a long time due to the defrosting operation, the refrigerating room temperature detecting means 29 detects this and the refrigerating room damper 26 is in an open state. Therefore, there is no problem with the circulation of air.

As a result, the refrigerant in the evaporator 12 does not condense and cannot exist in the evaporator 12 as a supercooled liquid due to forced convection heat exchange with the air in the refrigerating chamber 3 having a high temperature. Not only will evaporation be accelerated in the liquid phase. Further, since the freezer compartment damper 25 is closed, the temperature inside the freezer compartment 3 does not rise due to the operation of the internal fan 16.

The timer 24 integrates the time, and the predetermined time T
When the second has passed, the timer 24 outputs a signal. By this signal, the defrost control means 22 starts the operation of the compressor 9 (STEP 6) and starts the cooling operation. The cold air temperature detecting means 27 detects the cold air temperature Ter flowing out from the evaporator 12 by the freezing room temperature detecting means 28.
When the freezer compartment damper control means 30 determines that the air temperature has become lower than the air temperature Tf (STEP 7), the freezer compartment damper 25
Is opened and cooling of the freezer compartment 4 is started (STEP 8).

Next, a third embodiment will be described with reference to FIG. Reference numeral 31 denotes a defrosting heater control means, which disconnects the defrosting heater 14 at a predetermined cycle by the output of the defrosting control means 22.

Next, the operation will be described with reference to FIGS. The frost formation on the evaporator 12 progresses, and the defrost detection means 1
When 5 detects frost formation (STEP 1), this output causes the defrosting control means 22 to output a defrosting start signal to the freezer compartment damper control means 30, and to turn on the compressor 9 and the internal fan 16. While stopping, the defrosting heater 14 is energized to start defrosting (STEP 2). At this time, the temperature Ter of the cooling chamber 8 rises due to the energization of the defrosting heater 14. The freezer damper control means 30 detects that the temperature Ter of the cooling chamber 8 is higher than the temperature Tf of the freezer 4 from the outputs of the cool air temperature detector 27 and the freezer temperature detector 28 (STEP 3). , The freezer damper 25 is closed (STEP 4).

The evaporator 1 is heated by the heat generated by the defrosting heater 14.
2 The frost adhering to the surface is radiated from the defrosting heater, convection of air in the vicinity, and heat transfer by evaporation and condensation of the internal refrigerant heated in the evaporator 14 near the defrosting heater 14 , Thaw.

As a result, the frost on the surface of the evaporator 12 is completely melted. At this time, the defrosting completion detecting means 23 detects the completion of defrosting and outputs a signal to the defrosting controlling means 22 (STEP).
5).

In response to this signal, the defrost control means 22 outputs it to the defrost heater control means 31, and the defrost heater control means 31 causes the defrost heater 14 to move in a predetermined cycle (for example, O
Intermittent at N3 seconds and OFF 7 seconds (STEP 6). At the same time, the operation of the internal fan 16 and the integration of the timer 24 are started. At this time, the freezer compartment damper 25 is in the closed state, so that air begins to circulate in the refrigerating compartment 3. At this time, since the temperature Tp of the refrigerating compartment 3 has risen due to the refrigerating compartment damper 26 being stopped for a long time due to the defrosting operation, the refrigerating compartment temperature detecting means 29 detects this and the refrigerating compartment damper 26 is opened. Since it is in a state, there is no problem with the circulation of air.

As a result, the refrigerant inside the evaporator 12 is condensed by the forced convection heat exchange with the hot air, because the air inside the refrigerating chamber 3 having a high temperature is further heated by the intermittent energization of the defrosting heater 14. In addition, not only the supercooled liquid cannot exist in the evaporator 12, but also the liquid phase part is accelerated. Further, since the freezer compartment damper 25 is closed, the temperature inside the freezer compartment 3 does not rise due to the operation of the internal fan 16.

The timer 24 integrates the time, and the predetermined time T
When the second has passed, the timer 24 outputs a signal. By this signal, the defrost control means 22 stops the output to the defrost heater control means 31 (STEP 7), starts the operation of the compressor 9, and starts the cooling operation (STEP 8).

Then, the cool air temperature detecting means 27 confirms that the cool air temperature Ter flowing out from the evaporator 12 becomes lower than the air temperature Tf of the freezing compartment 4 detected by the freezing compartment temperature detecting means 28. 30 judges (STE
P9), the freezer compartment damper 25 is opened, and cooling of the freezer compartment 4 is started (STEP 10).

[0041]

With the above structure, the refrigerator of the present invention has
Install a refrigeration cycle in which a compressor, a condenser, a capillary tube, and an evaporator are sequentially connected in an annular shape, and divide the inside by a partition to form a refrigerating room and a refrigerator body having a freezing room, and the evaporation. A fan inside the refrigerator and heat exchange between the air in the refrigerator body, a defrosting heater for the evaporator, a defrosting end detecting means for detecting the defrosting end of the evaporator, and a defrosting end detecting means. Defrost control means for stopping the energization of the defrosting heater by the output and at the same time starting the operation of the internal fan, starting the compressor after a predetermined time, and starting the normal operation.

Further, an air passage for circulating the air cooled by the evaporator to the refrigerating compartment and the freezing compartment, a freezing compartment of the air passage, a freezing compartment damper provided at an opening of the refrigerating compartment, a refrigeration compartment damper, and an evaporator. Cooler temperature detecting means provided near the air outlet of the refrigerator, freezing room temperature detecting means provided in the freezing room, and a freezer compartment damper for opening and closing the freezing room damper by the outputs of the cold air temperature detecting means and the freezing room temperature detecting means. Control means installed.

Further, after the defrosting is completed, a defrosting heater control means for repeating energization and de-energization of the defrosting heater at a predetermined cycle is provided until the compressor is activated.

With these constructions, the refrigerant in the evaporator is vaporized and vaporized at the end of defrosting to prevent the compressor from sucking the liquid refrigerant at the time of starting the compressor and prevent the liquid compression at the time of starting. Therefore, it has a great effect on reliability.

Furthermore, in the second embodiment, since the freezer compartment damper is closed, the refrigerant in the evaporator is vaporized at the end of defrosting while preventing the temperature rise in the freezer compartment due to the internal fan operation. Since it prevents the compressor from sucking the liquid refrigerant at the time of starting the compressor and prevents the liquid compression at the time of starting, it has a great effect on the reliability.

Furthermore, in the third embodiment, the defrosting heater is intermittently operated to further promote the evaporation and vaporization of the refrigerant, which prevents the compressor from sucking the liquid refrigerant at the time of starting the compressor and starts the operation. Since it prevents liquid compression at the time, it has a great effect on reliability.

[Brief description of drawings]

FIG. 1 is a refrigeration cycle diagram of a refrigerator according to a first embodiment of the present invention.

FIG. 2 is a block diagram of an electric circuit of the refrigerator of the embodiment.

FIG. 3 is a flowchart of the operation of the embodiment.

FIG. 4 is a timing chart of the operation of the embodiment.

FIG. 5 is a refrigeration cycle diagram of the refrigerator according to the second embodiment of the present invention.

FIG. 6 is a block diagram of an electric circuit of the embodiment.

FIG. 7 is a flowchart of the operation of the embodiment.

FIG. 8 is a timing chart of the operation of the embodiment.

FIG. 9 is a block diagram of an electric circuit of a refrigerator according to a third embodiment of the present invention.

FIG. 10 is a flowchart of the operation of the embodiment.

FIG. 11 is a timing chart of the operation of the embodiment.

FIG. 12: Refrigeration cycle diagram of a conventional refrigerator

FIG. 13 is a timing chart of the operation of the conventional example.

[Explanation of symbols]

 1 Main Body 2 Partition 3 Refrigerator 4 Freezer 9 Compressor 10 Condenser 11 Capillary Tube 12 Evaporator 14 Defrost Heater 16 Internal Fan 22 Defrost Control Means 23 Defrost End Detector 25 Freezer Chamber Damper 26 Refrigerator Chamber Damper 27 Cold air temperature detecting means 28 Freezing room temperature detecting means 30 Freezing room damper control means 31 Defrost heater control means

Claims (3)

[Claims] 1. A compressor, a condenser, a capillary tube,
A refrigerating cycle in which evaporators are sequentially connected in a ring is installed, and a refrigerator body provided with a refrigerating room and a freezing room formed by dividing the inside by partition walls, and the evaporator and the air in the refrigerator body are heated. An in-compartment fan to be replaced, a heater for defrosting the evaporator, a defrosting end detecting means for detecting the end of defrosting of the evaporator, and a defrosting heater powered by the output of the defrosting end detecting means. A refrigerator provided with defrost control means for starting the operation of the internal fan at the same time as stopping, starting the compressor after a predetermined time, and starting normal operation. 2. An air passage for circulating air cooled by an evaporator to a refrigerating compartment and a freezing compartment, a freezing compartment of the air passage, a freezing compartment damper provided at an opening of the refrigerating compartment, a refrigeration compartment damper, and an evaporator. Cooler temperature detecting means provided near the air outlet of the refrigerator, freezing room temperature detecting means provided in the freezing room, and a freezer compartment damper for opening and closing the freezing room damper by the outputs of the cold air temperature detecting means and the freezing room temperature detecting means. The refrigerator according to claim 1, further comprising a control means. 3. The defrosting heater control means for repeating energization and de-energization of the defrosting heater at a predetermined cycle until the compressor is activated after the defrosting is completed. Refrigerator described.