JP2000230768A - Refrigerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To contrive the reduction of amount of refrigerant for a cooling system as well as the improvement of efficiency of the cooling system by switching the cooling of a refrigerating chamber and a freezing chamber. SOLUTION: In a refrigerator, a closed loop is formed of a compressor 1, a condenser 2, a first flow passage control means 10, a first capillary 7 and a first evaporator 3 while a second flow passage control means 11, a second capillary 8, a second evaporator 5 and a non-return valve 20 are connected in parallel to a first flow passage control means 10, the first capillary 7 and the first evaporator 3, to switch the flow of refrigerant by the first and second flow passage control means. When the cooling of a freezing chamber 6 is switched into the cooling of the refrigerating chamber 4, the compressor 1 is operated under a condition that both of the first and second flow passage control means are closed for a predetermined period of time and, thereafter, the cooling of the refrigerating chamber 4 is started. According to this method, the refrigerant, stayed in the second evaporator 5, can be purged quickly to the side of the compressor 1 whereby the refrigerating chamber 4 can be cooled efficiently.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling system for cooling a freezer compartment and a refrigerator compartment independently of each other, to reduce the amount of refrigerant, increase efficiency, and improve safety.

[0002]

2. Description of the Related Art FIG. 13 is a schematic view of a refrigerator disclosed in Japanese Patent Publication No. 62-22396 as an example of a conventional cooling cycle and a refrigerator.

[0003] 1 is a constant speed compressor, 2 is a condenser, 3 is a first evaporator disposed in a refrigerator compartment 4, 5 is a second evaporator disposed in a freezer compartment 6 It is an evaporator.

[0004] Reference numeral 7 denotes a first capillary disposed on the upstream side of the refrigerant circuit of the first evaporator 3 for cooling the refrigerator compartment,
Reference numeral 8 denotes a second capillary arranged on the upstream side of the refrigerant circuit of the second evaporator 5 for cooling the freezing room, and 9 is provided on the downstream side of the second evaporator 5 for cooling the freezing room. It is a check valve.

[0005] Reference numeral 10 denotes a first opening / closing valve disposed downstream of the first evaporator 3 in the refrigerant circuit, and 11 denotes a second opening / closing valve provided upstream of the second capillary 8 in the refrigerant circuit. It is.

The operation of the conventional refrigerator configured as described above will be described below.

[0007] The operation of the refrigeration cycle is performed as follows. First, the refrigerant compressed by the compressor 1 is condensed and liquefied in the condenser 2. The condensed refrigerant is decompressed by the first capillary 7 or the second capillary 8, flows into the first evaporator 3 and the second evaporator 5, respectively, is evaporated and vaporized, and then returns to the compressor 1 again. Inhaled.

[0008] The first evaporator 3 and the second evaporator 5 and the refrigerating chamber 4, which have a relatively low temperature due to evaporation and vaporization of the refrigerant,
Each room is cooled by the heat exchange of the air in the freezing room 6.

The cooling operation of the refrigerator is performed as follows by temperature detecting means and control means of each room (not shown).

When each of the temperature detecting means in the refrigerator compartment 4 and the freezer compartment 6 detects a temperature rise above a predetermined value, the compressor 1 is started and the refrigeration cycle is operated. The first on-off valve 10 is opened and the second on-off valve 11 is closed until the temperature detecting means of the refrigerator compartment 4 becomes lower than a predetermined value.

As a result, the refrigerant does not flow into the second evaporator 5 but flows only into the first evaporator 3. At this time, the evaporating temperature of the refrigeration cycle is set at -5 to 0 ° C. with respect to the temperature of the refrigerating room 4 of about 5 ° C.
The compressor can be operated with a coefficient of performance of 2-2.5 times the evaporation temperature of -25C.

When the temperature of the refrigerating compartment 4 is lowered by cooling, and the temperature detecting means detects the temperature below a predetermined value, the first on-off valve 10 is opened.
Is closed, and the second on-off valve 11 is opened.

As a result, the refrigerant flows into the second evaporator 5, and the freezing chamber 6 is cooled. The evaporating temperature of the refrigerating cycle at this time is cooled at a normal evaporating temperature while the temperature of the freezing room is set at about -18 ° C.

As described above, the refrigerating compartment 4 and the freezing compartment 6 are alternately cooled by distributing the refrigerant supply time to the evaporator and alternately cooling the refrigerant. By circulating through the compressor, a low-pressure pressure regulating valve is not required, and a high evaporation temperature (-5 to 0 ° C) is possible, the compression ratio of the compressor 1 can be reduced, and the efficiency is improved by operating with a high coefficient of performance. Things.

Further, the check valve 9 prevents the refrigerant from flowing into the second evaporator 5 because the evaporation temperature during the cooling of the refrigerator compartment 4 is high.

When the freezing compartment 6 is cooled, the amount of the refrigerant is smaller than that during the cooling of the refrigerator compartment 4, so that the amount of the refrigerant is usually excessive. However, the first on-off valve 10 is provided downstream of the first evaporator 3 and is closed, so that the refrigerant can be stored in the first evaporator 3 and the amount of the refrigerant can be adjusted.

[0017]

In the above-mentioned conventional refrigerator, the refrigerating compartment 4 and the freezing compartment 6 are alternately and repeatedly cooled by distributing the refrigerant supply time to the evaporator.
The refrigeration cycle at the time of cooling can be operated at a relatively high evaporation temperature (−5 to 0 ° C.) where the coefficient of performance of the compressor 1 is good.

However, when the refrigerator compartment 4 is cooled, the freezer compartment 6
Is low, for example, about −18 ° C., the pressure of the second evaporator 5 disposed in the freezing chamber 6 becomes low, and the refrigerant retained in the second evaporator 5 is removed by the second evaporation. It is difficult to flow out of the container 5. As a result, sufficient refrigerant is not supplied to the first evaporator 3, and the amount of circulating refrigerant becomes insufficient, resulting in a decrease in efficiency.

Due to the above factors, the required amount of refrigerant increases, and when a flammable refrigerant is used, there is a large risk of refrigerant leakage and a problem.

The present invention solves the above-mentioned conventional problems, and it is possible to save energy by reducing the amount of refrigerant and improving the efficiency of a cooling system that switches between the refrigerator compartment and the freezer compartment. It is intended to provide a refrigerator.

[0021]

In order to achieve this object, a refrigerator according to the present invention comprises a refrigerator box comprising a refrigerator compartment and a freezer compartment, a first evaporator and a freezer compartment in the refrigerator compartment. A second evaporator is disposed, a variable capacity compressor, a condenser, a first flow path control means, a first capillary, the first evaporator, a second flow path control means, and a second evaporator. A second capillary, the second evaporator, and a check valve are provided, and a closed loop is formed by the compressor, the condenser, the first flow path control means, the first capillary, and the first evaporator. And the second flow path control means, the second capillary, and the second capillary so as to be parallel to the first flow path control means, the first capillary, and the first evaporator. An evaporator is connected to the check valve, and the flow of the refrigerant is switched by the first and second flow path control means. When switching from freezer compartment cooling to refrigerator compartment cooling, the compressor is operated in a state in which both the first and second flow path control means are closed for a predetermined time, and then the refrigerator compartment cooling is started. Features.

According to the present invention, after the freezer compartment cooling is completed, the compressor is operated in a state where the first flow path control means and the second flow path control means are closed for a predetermined time and the flow of the refrigerant is completely shut off. As a result, the pressure in the compressor becomes lower than that during normal operation, so that the refrigerant that has accumulated in the second evaporator can be expelled from the second evaporator to the compressor side.

As a result, sufficient refrigerant for cooling the refrigerator compartment is supplied to the first evaporator when the mode is switched to the refrigerator compartment cooling, so that the refrigerant circulation amount is not insufficient, and the refrigerator compartment is efficiently cooled. Becomes possible.

Further, since the refrigerant can be used efficiently, the amount of the refrigerant can be reduced, and when a flammable refrigerant is used, the risk of leakage of the refrigerant can be reduced.

Further, at the time of switching from freezing compartment cooling to refrigerator compartment cooling, the compressor is operated at a higher speed than during normal operation with both the first and second flow path control means closed for a predetermined time. It is characterized in that the refrigerator compartment cooling is started at a normal rotation speed.

According to the present invention, after the freezer compartment cooling is completed, the first flow control means and the second flow control means are closed for a predetermined time and the compressor is normally operated in a state in which the flow of the refrigerant is completely shut off. By operating at a higher speed than when the pressure in the compressor becomes considerably lower than in normal operation, the refrigerant that has accumulated in the second evaporator is transferred from the second evaporator to the compressor side. It will be possible to drive out quickly. as a result,
Since the time for operating the compressor with both the first and second flow path control means closed can be reduced, the temperature rise of the refrigerator compartment can be reduced, and the refrigerator compartment can be more efficiently cooled. Becomes

The fins are arranged in parallel with each other, and fins through which the gas flows and a heat transfer tube penetrating through the fins and having a structure in which the refrigerant does not flow from the inlet to the outlet in the direction opposite to the direction of gravity. It is characterized by having a second evaporator.

According to the present invention, the heat transfer tube of the second evaporator has a structure in which the refrigerant does not flow from the inlet to the outlet in the direction opposite to the direction of gravity. Since the resistance is reduced and the refrigerant remaining in the second evaporator can be smoothly expelled to the compressor side, the compressor is operated with both the first and second flow path control means closed. The time can be further reduced, and the refrigerator compartment can be cooled more efficiently.

Also, during cooling of the freezing chamber, the flow resistance in the second evaporator is small, so that the oil returns to the compressor is improved. Oil accumulation can be prevented.

Further, the freezer compartment is disposed below the refrigerating compartment.

According to the present invention, the pipe length of the second suction line can be shortened, and as a result, the flow resistance of the second suction line decreases, and the refrigerant that has accumulated in the second evaporator can be removed. Since it is possible to drive the compressor more smoothly to the compressor side, it is possible to further reduce the time for operating the compressor with both the first and second flow path control means closed, and to cool the refrigerator compartment more efficiently. It is possible to do.

Further, after exiting the second evaporator, the piping structure is such that the second suction line is not raised along the back of the refrigerator and the bottom surface of the refrigerator is crawled and then connected to the compressor. And

According to the present invention, since the suction line, which has conventionally raised the back of the refrigerator for heat exchange with the capillary, has a piping structure that does not start by effectively utilizing the bottom of the refrigerator, the second suction line has the following structure. Since the flow path resistance can be reduced and the refrigerant remaining in the second evaporator can be expelled more smoothly to the compressor side, the compression can be performed with both the first and second flow path control means closed. The time to drive the machine can be further reduced,
Further, the refrigerator compartment can be cooled more efficiently.

[0034] The second suction line is characterized in that heat is exchanged with the condenser in a machine room arranged below the refrigerator.

According to the present invention, the relatively high-temperature refrigerant passing through the condenser can be cooled by the relatively low-temperature refrigerant passing through the second suction line, so that the degree of supercooling at the second capillary inlet is large. The refrigerating capacity can be improved, and the freezing room can be efficiently cooled.

The refrigerant having a relatively low temperature in the second suction line absorbs heat by exchanging heat with the condenser having a relatively high temperature, and the refrigerant which has not been completely evaporated in the second evaporator is removed. Since evaporation takes place in the second suction line, it is possible to reduce liquid return, which causes an increase in power consumption and damage to the compressor.

Further, an evaporating dish is provided below the second suction line which crawls in the machine room provided below the refrigerator.

According to the present invention, the amount of circulating refrigerant in the system becomes excessive during cooling of the freezing room, and the relatively low-temperature refrigerant that has not completely evaporated in the first and second evaporators returns to the compressor. The return reduces the temperature of the pipe in the second suction line, and the dew can be accumulated in the evaporating dish when dew occurs on the pipe surface. As a result, it is possible to prevent water leakage from the refrigerator installation portion and prevent electric leakage, thereby improving safety particularly when a flammable refrigerant is used.

[0039]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is directed to a refrigerator box composed of a refrigerator compartment and a freezer compartment, a first evaporator in the refrigerator compartment and a second evaporator in the freezer compartment. And a variable capacity compressor, a condenser, a first flow path control means, a first capillary, the first evaporator, a second flow path control means, and a second capillary. And the second evaporator and a check valve, forming a closed loop with the compressor, the condenser, the first flow path control means, the first capillary, and the first evaporator. The second flow path control means, the second capillary, and the second evaporator so as to be in parallel with the first flow path control means, the first capillary, and the first evaporator. The check valve is connected, and the flow of the refrigerant is switched by the first and second flow path control means. When switched to the refrigerating compartment cooling from a predetermined time first, after driving the compressor while closed together second flow path control means and to start the refrigerating compartment cooling.

According to the present invention, after the freezer compartment cooling is completed, the compressor is operated in a state where the first flow path control means and the second flow path control means are closed for a predetermined time and the flow of the refrigerant is completely shut off. As a result, the pressure in the compressor becomes lower than that during normal operation, so that the refrigerant that has accumulated in the second evaporator can be expelled from the second evaporator to the compressor side. As a result, when the mode is switched to the refrigerator compartment cooling, sufficient refrigerant for cooling the refrigerator compartment is supplied to the first evaporator, so that the refrigerant circulation amount is not insufficient, and the refrigerator compartment can be efficiently cooled. Become.

Further, since the refrigerant can be used efficiently, the amount of the refrigerant can be reduced, and when a flammable refrigerant is used, the risk of leakage of the refrigerant can be reduced.

According to a second aspect of the present invention, when switching from freezer compartment cooling to refrigerator compartment cooling, the first and second predetermined time periods are set.
After the compressor is operated at a higher rotation speed than in the normal operation with both the second flow path control means closed, cooling of the refrigerator compartment is started at the normal rotation speed.

According to the present invention, after the freezer compartment cooling is completed, the first flow control means and the second flow control means are closed for a predetermined time and the compressor is normally operated in a state in which the flow of the refrigerant is completely shut off. By operating at a higher speed than when the pressure in the compressor becomes considerably lower than in normal operation, the refrigerant that has accumulated in the second evaporator is transferred from the second evaporator to the compressor side. It will be possible to drive out quickly.

As a result, the time for operating the compressor with both the first and second flow path control means closed can be reduced, so that the temperature rise in the refrigerator compartment can be reduced, and the refrigerator compartment can be more efficiently used. Can be cooled.

According to a third aspect of the present invention, a fin is arranged in parallel, and a gas flows between the fin and the fin.
A second evaporator comprising a heat transfer tube having a structure in which the refrigerant does not flow in the direction opposite to the direction of gravity from the inlet to the outlet in the inside is provided.

According to the present invention, the heat transfer tube of the second evaporator has a structure in which the refrigerant does not flow from the inlet to the outlet in the direction opposite to the direction of gravity, so that the flow path in the second evaporator is reduced. Since the resistance is reduced and the refrigerant remaining in the second evaporator can be smoothly expelled to the compressor side, the compressor is operated with both the first and second flow path control means closed. The time can be further reduced, and the refrigerator compartment can be cooled more efficiently.

Further, during cooling of the freezing chamber, the flow resistance in the second evaporator is small, so that the return of oil to the compressor is improved, so that the amount of refrigerant circulating in the second evaporator is reduced. Oil accumulation can be prevented.

The invention according to a fourth aspect is characterized in that the freezing compartment is disposed below the refrigerating compartment.

According to the present invention, the pipe length of the second suction line can be shortened, and as a result, the flow resistance of the second suction line decreases, and the refrigerant that has accumulated in the second evaporator can be removed. Since it is possible to drive the compressor more smoothly to the compressor side, it is possible to further reduce the time for operating the compressor with both the first and second flow path control means closed, and to cool the refrigerator compartment more efficiently. It is possible to do.

According to a fifth aspect of the present invention, after exiting the second evaporator, the second suction line is not set up along the back of the refrigerator, and the bottom of the refrigerator is crawled, and then connected to the compressor. It is characterized by a piping structure.

According to the present invention, since the suction line, which conventionally raised the back of the refrigerator for heat exchange with the capillary, has a piping structure that does not start by effectively utilizing the bottom surface of the refrigerator, the second suction line has Since the flow path resistance can be reduced and the refrigerant remaining in the second evaporator can be expelled more smoothly to the compressor side, the first and second flow path control means are both closed. The operation time of the compressor can be further reduced, and the refrigerator compartment can be cooled more efficiently.

The invention according to claim 6 is characterized in that the second suction line exchanges heat with a condenser in a machine room arranged below the refrigerator.

According to the present invention, since the relatively high-temperature refrigerant passing through the condenser can be cooled by the relatively low-temperature refrigerant passing through the second suction line, the degree of supercooling at the second capillary inlet is increased. The refrigerating capacity can be improved, and the freezing room can be efficiently cooled.

The refrigerant having a relatively low temperature in the second suction line absorbs heat by exchanging heat with the condenser having a relatively high temperature, and the refrigerant which has not been completely evaporated in the second evaporator is removed. Since evaporation takes place in the second suction line, it is possible to reduce liquid return, which causes an increase in power consumption and damage to the compressor.

The invention according to claim 7 is characterized in that an evaporating dish is provided below a second suction line which crawls in a machine room provided below a refrigerator.

According to the present invention, the amount of circulating refrigerant in the system during cooling of the freezing chamber becomes excessive, and the relatively low-temperature refrigerant that has not been completely evaporated in the second evaporator returns to the compressor to return to the compressor. When the temperature of the pipe in the second suction line decreases and dew occurs on the pipe surface, dew can be accumulated in the evaporating dish. As a result, it is possible to prevent water leakage from the refrigerator installation portion and prevent electric leakage, thereby improving safety particularly when a flammable refrigerant is used.

[0057]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to FIGS. Detailed descriptions of the same components as those of the conventional example are omitted, and the same reference numerals are given.

(Embodiment 1) FIG. 1 is a longitudinal sectional view of a refrigerator according to Embodiment 1 of the present invention, and FIG. 2 is a time chart of the embodiment.

Numeral 21 denotes a refrigerator box in which a refrigerator compartment 4 which is a relatively high temperature compartment and a freezing compartment 6 which is a relatively low temperature compartment are arranged, and are insulated from the surroundings by a heat insulating material such as urethane. It is composed. Storage of foods and the like is carried out through an insulated door (not shown).

The refrigerator compartment 4 is usually at 3 to 5 ° C. for refrigerated storage.
However, the temperature may be set at a slightly lower temperature for improving freshness, for example, -3 to 0 ° C., so that the user can freely switch the temperature setting as described above depending on stored items. In some cases, the temperature may be set slightly higher, for example, about 10 ° C. for freshening wine, root vegetables, and the like.

The freezer compartment 6 is usually set at -22 to refrigerated storage.
Although it is set at -18 ° C, it may be set at a lower temperature, for example, -30 to -25 ° C, for improving freshness.

The refrigerating cycle 12 includes a compressor 1, a condenser 2, a first motor-operated valve 10 as first flow path control means, a first capillary 7, a first evaporator 3, and a first suction line 18 Are sequentially connected, and the second electric motor, which is the second flow path control means, is connected in parallel with the first electric valve 10, the first capillary 7, the first evaporator 3, and the first suction line 18. The check valve 20 is connected to the valve 11, the second capillary 8, the second evaporator 5, the second suction line 19, and the second suction line.

The first and second motor-operated valves are operated by, for example, a pulse motor, and are energized only during opening and closing operations.

The first evaporator 3 is disposed in the refrigerator compartment 4, for example, on the inner surface of the refrigerator compartment. In the vicinity, the air in the compartment of the refrigerator compartment 4 is passed through the first evaporator 3 and circulated. A first electric fan 13 is provided.

The second evaporator 5 is disposed in the freezing compartment 6, for example, at the back of the freezing compartment. In the vicinity, the air in the compartment of the freezing compartment 6 is passed through the second evaporator 5. A second electric fan 14 for circulation is provided.

The compressor 1, the condenser 2, the first motor-operated valve 10, the second motor-operated valve 11, and the check valve 20 are provided inside the refrigerator box 21 in view of improving safety when a flammable refrigerant is used. It is arranged in the machine room 15 to reduce the number of pipe connection points.

The refrigerant returning from each evaporator passes through the compressor suction pipe 16, is discharged into the internal space of the compressor 1, and is then discharged through the compressor discharge pipe 17.

The compressor 1 is of a variable capacity type that can change the refrigeration capacity by controlling the amount of circulating refrigerant by controlling the number of revolutions, for example.

The refrigerating compartment 4 and the freezing compartment 6 are provided with temperature detecting means, for example, a thermistor, for detecting the temperature in the compartment (not shown). The compressor 1, the first motor-operated valve 10, and the second electric motor A control unit (not shown) for controlling the valve 11, the first electric fan 13, and the second electric fan 14 is provided.

The refrigerator configured as described above
The cooling timing of the refrigerating compartment 4 and the freezing compartment 6 will be described based on the time chart of FIG.

While the compressor is stopped, the refrigerator compartment 4 and the freezer compartment 6
When either one of the temperature detecting means detects a temperature equal to or higher than a predetermined temperature, the control means receives this signal and, for example, the temperature detecting means of the freezing compartment 6 detects a temperature equal to or higher than the predetermined temperature (t2H). Upon detection, the compressor 1 and the second electric fan 14 are operated, the second electric valve 11 is opened, and the first electric valve is closed (T1).

The high-temperature and high-pressure refrigerant discharged by the operation of the compressor 1 radiates heat in the condenser 2 to be condensed and liquefied, and reaches the second capillary 8 via the second electric valve 11. Thereafter, the pressure is reduced while exchanging heat with the second suction line 19 in the second capillary 8 and reaches the second evaporator 5. The heat is actively exchanged with the air in the freezing compartment 6 by the operation of the second electric fan 14, the refrigerant evaporates and evaporates in the second evaporator 5, and the heat-exchanged air is discharged as lower-temperature air. Then, the freezing room 6 is cooled. The vaporized refrigerant is sucked into the compressor 1 via the second suction line 19.

When the temperature detecting means of the freezer compartment 6 detects a temperature lower than a predetermined temperature (t2L) during the cooling of the freezer compartment 6, the second electric valve 11 is closed, and the second electric fan 14 is closed.
Is stopped and cooling of the freezing compartment 6 is terminated (T2).

For a predetermined time, the compressor is operated with the first motor-operated valve 10 and the second motor-operated valve 11 closed and the flow of the refrigerant cut off (T2 to T3).

After a lapse of a predetermined time, the first electric valve 10 is opened and the first electric fan 13 is operated to start cooling the refrigerator compartment 4 (T3).

The refrigerant reaches the first capillary 7 via the first electric valve 10. Thereafter, the pressure is reduced while exchanging heat with the first suction line 18 in the first capillary 7, and reaches the first evaporator 3. The operation of the first electric fan 13 actively exchanges heat with the air in the refrigerator compartment 4, the refrigerant evaporates and evaporates in the first evaporator 3, and the heat-exchanged air becomes relatively low-temperature air. The discharged refrigerator cools the refrigerator compartment 4. The vaporized refrigerant passes through the first suction line 18 and passes through the compressor 1
Inhaled.

When the temperature detecting means of the freezer compartment 6 detects a temperature equal to or higher than a predetermined temperature (t2H) during the cooling of the refrigerator compartment 4, the first electric valve 10 is closed and the first electric fan 13 is stopped at the same time. At the same time, the second electric valve 11 is opened, the second electric fan 14 is operated, and the cooling of the freezing compartment 6 is started (T4).

By repeating the above operation and switching the flow of the refrigerant, the refrigerating compartment 4 and the freezing compartment 6 are alternately cooled, and the temperature detecting means of the refrigerating compartment 4 and the freezing compartment 6 are both set to a predetermined temperature. When it is detected that it is lower than (t1 and t2L), the compressor 1 is stopped (T5).

After cooling the freezer compartment, the first motor-operated valve 10 and the second motor-operated valve 11 are closed for a predetermined time, and the compressor is operated in a state in which the flow of the refrigerant is completely shut off. Since the pressure is lower than that during the operation, the refrigerant that has accumulated in the second evaporator can be expelled from the second evaporator to the compressor side. As a result, when the mode is switched to the refrigerator compartment cooling, sufficient refrigerant for cooling the refrigerator compartment is supplied to the first evaporator, so that the refrigerant circulation amount is not insufficient, and the refrigerator compartment can be efficiently cooled. Become.

Further, since the refrigerant can be used efficiently, the amount of the refrigerant can be reduced, and when a flammable refrigerant is used, the risk of leakage of the refrigerant can be reduced.

Similarly, when switching from the cooling of the refrigerator compartment 4 to the cooling of the freezer compartment 6, the compressor 1 is operated for a predetermined time with both the first motor-operated valve 10 and the second motor-operated valve 11 closed. When the cooling of the freezing compartment 6 is started, the freezing compartment 6 can be quickly expelled to the refrigerant compressor 1 staying in the first evaporator 3, so that the freezing compartment can be efficiently cooled.

The first flow path control means 10 and the second flow path control means 11 are installed on the inlet side of the first capillary 7 and the second capillary 8 respectively. Since the circuit is switched after the refrigerant is depressurized, the operating pressure difference of the flow path control means is small, and a small torque is sufficient, so that the size can be reduced and the power consumption can be reduced.

Although the first flow path control means 10 and the second flow path control means 11 are motorized valves controlled by a pulse motor, similar effects can be obtained by using electromagnetic valves.

Although the first flow control means 10 and the second flow control means 11 have been described as means for switching the flow of the refrigerant, the flow to the first and second capillaries has been described. The same effect can be obtained and the storage ability can be improved by using an electric three-way valve having a structure that can alternately open and close the passage and close the passage similarly.

(Embodiment 2) FIG. 3 is a time chart of the embodiment.

The description of the same control as in the first embodiment will be omitted.

When the temperature detecting means of the freezing room 6 detects a temperature lower than a predetermined temperature (t2L) during cooling of the freezing room 6, the second motor-operated valve 11 is closed, and the second electric fan 14
To stop the freezing room 6 cooling, and increase the rotation speed of the compressor 1 (T6).

For a predetermined period of time, the compressor is operated at a higher speed than during normal operation with the first motor-operated valve 10 and the second motor-operated valve 11 closed and the flow of refrigerant is shut off (T6 to T7).

After a lapse of a predetermined time, the first electric valve 10 is opened and the first electric fan 13 is operated to return the compressor to the normal rotation speed and start cooling the refrigerator compartment 4 (T7).

When the temperature detecting means of the freezer compartment 6 detects a temperature equal to or higher than a predetermined temperature (t2H) during the cooling of the refrigerator compartment 4, the first electric valve 10 is closed and the first electric fan 13 is stopped at the same time. At the same time, the second electric valve 11 is opened, the second electric fan 14 is operated, and the cooling of the freezing compartment 6 is started (T8).

By repeating the above operation and switching the flow of the refrigerant, the refrigerating compartment 4 and the freezing compartment 6 are alternately cooled, and the temperature detecting means of the refrigerating compartment 4 and the freezing compartment 6 are both set to a predetermined temperature. When it is detected that it is lower than (t1 and t2L), the compressor 1 is stopped (T9).

After the cooling of the freezing compartment 6, the first motor-operated valve 10 and the second motor-operated valve 11 are closed for a predetermined period of time, and the compressor 1 is operated at a higher speed than in the normal operation with the flow of the refrigerant completely shut off. As a result, the pressure in the compressor 1 becomes considerably lower than that in the normal operation, and the refrigerant remaining in the second evaporator 5 is quickly expelled from the second evaporator 5 to the compressor 1 side. It becomes possible. As a result, the first motor-operated valve 1
The time for operating the compressor 1 with both the 0 and the second motor-operated valves 11 closed can be shortened, the temperature rise in the refrigerator compartment 4 can be reduced, and the refrigerator compartment 4 can be cooled efficiently. It becomes possible.

A temperature detecting means for detecting the temperature of the pipe of the second evaporator 5 is provided. When the temperature detecting means detects a temperature equal to or lower than a predetermined temperature at the time of switching from freezing room cooling to refrigerating room cooling, the first electric valve 10 is activated. By providing a control means that opens and starts cooling the refrigerator compartment, an excessive pressure drop can be prevented, and the load on the compressor 1 can be reduced.

(Embodiment 3) The detailed description of the same components as in Embodiment 1 is omitted, and the same reference numerals are given.

FIG. 4A is a schematic diagram of a second evaporator according to the third embodiment of the present invention, and FIG. 4B is a schematic diagram of a fin used in the second evaporator.

The second evaporator 5 has a structure in which fins 23 are arranged in parallel and gas flows between the fins 23, and the refrigerant does not flow in the interior from the inlet to the outlet in the direction opposite to the direction of gravity. And a heat transfer tube 22.

Reference numeral 24 denotes a hole provided in the fin, through which the heat transfer tube 22 passes.

Since the heat transfer tube 22 of the second evaporator 5 has a structure in which the refrigerant does not flow from the inlet to the outlet in the direction opposite to the direction of gravity, the flow path resistance in the second evaporator 5 is reduced. Become. As a result, when the compressor 1 is operated at a higher speed than during the normal operation with the first motor-operated valve 10 and the second motor-operated valve 11 closed for a predetermined time after the freezing chamber 6 is cooled,
The refrigerant staying in the second evaporator 5 is removed from the second evaporator 5.
From the compressor 1 to the compressor 1 side, the time for operating the compressor 1 with both the first motor-operated valve 10 and the second motor-operated valve 11 closed can be further reduced, and the efficiency can be further improved. The refrigerator compartment 4 can be cooled well.

During the cooling of the freezing chamber 6, the flow resistance in the second evaporator 5 is small, so that the return of oil to the compressor 1 is improved. It is possible to prevent oil accumulation in the vessel 5.

As shown in FIG. 4, in order to improve the heat transfer coefficient on the air side, the heat transfer tube 22 has a piping structure in which the heat transfer tube 22 is alternately lowered from above to below in the direction of gravity. Alternatively, the pipe structure may be vertically lowered. In this embodiment, the pipe structure in which the heat transfer tubes 22 are not arranged in a horizontal direction as shown in FIG. 4 has been described. As shown in (2), the same effect can be obtained even if the pipe structure does not allow the flow of the refrigerant to flow from the inlet to the outlet in the direction opposite to the direction of gravity even if the pipe structure has the heat transfer tubes arranged in the horizontal direction.

When the heat transfer tube 22 of the second evaporator 5 is inclined in the weight direction as shown in FIG.
Since the flow path resistance inside the first motor-operated valve 10 can be more smoothly driven to the compressor 1 side,
And the second motor-operated valve 11 are closed.
Can be further reduced, and the refrigerator compartment 4 can be cooled more efficiently.

(Embodiment 4) Detailed descriptions of the same components as those in Embodiment 1 are omitted, and the same reference numerals are given.

FIG. 7 is a longitudinal sectional view of a refrigerator according to Embodiment 4 of the present invention.

Reference numeral 21 denotes a refrigerator box, in which a refrigerator compartment 4 which is a relatively high-temperature section is disposed in an upper portion, and a freezing compartment 6 which is a relatively low-temperature portion is disposed in a lower portion. 15 are short. As a result, the pipe length of the second suction line 19 is shorter than before.

Since the pipe length of the second suction line 19 is shorter than the conventional one, the flow resistance of the second suction line 19 becomes smaller. As a result, when the compressor 1 is operated with the first motor-operated valve 10 and the second motor-operated valve 11 closed for a predetermined period of time after the freezing chamber 6 has been cooled, the compressor 1 stays in the second evaporator 5. Refrigerant can be expelled from the second evaporator 5 to the compressor 1 more smoothly,
The time for operating the compressor 1 with both the first motor-operated valve 10 and the second motor-operated valve 11 closed can be further reduced, and the refrigerator compartment 4 can be cooled more efficiently.

(Embodiment 5) The same components as those in Embodiment 1 are not described in detail, and are denoted by the same reference numerals.

FIG. 8 is a longitudinal sectional view of a refrigerator according to the fifth embodiment of the present invention.

In FIG. 8, after exiting the second evaporator 5,
The second suction line 19 has a piping structure in which the bottom of the refrigerator is crawled without rising along the back of the refrigerator and then connected to the compressor.

Further, the second capillary 8 and the second suction line 19 exchange heat inside the heat insulating material on the bottom of the refrigerator.

A piping structure in which the second suction line 19 is not set up along the back of the refrigerator by effectively utilizing the space on the bottom of the refrigerator instead of the suction line that has set up the back of the refrigerator to exchange heat with the capillary. And the second suction line 1
9 becomes smaller.

As a result, when the compressor 1 is operated with the first motor-operated valve 10 and the second motor-operated valve 11 closed for a predetermined time after the freezing compartment 6 has been cooled, the inside of the second evaporator 5 is Since the staying refrigerant can be more smoothly expelled from the second evaporator 5 to the compressor 1 side, the compressor 1 is operated with both the first electric valve 10 and the second electric valve 11 closed. The operation time can be further reduced, and the refrigerator compartment 4 can be cooled more efficiently.

(Embodiment 6) The same components as those in Embodiment 1 are not described in detail, and are denoted by the same reference numerals. FIG. 9 is a longitudinal sectional view of a refrigerator according to the sixth embodiment of the present invention.
FIG. 13 is a cross-sectional view of a refrigerator according to a sixth embodiment of the present invention.

In FIG. 9, reference numeral 2 denotes a condenser provided in a machine room 15 provided below the refrigerator, and reference numeral 19 denotes a second suction line connected to the compressor 1 without standing up along the back of the refrigerator. It is.

In FIG. 10, the condenser 2 and the second suction line 19 exchange heat.

The operation of the refrigerator having the above-described configuration will be described below with the freezer compartment 6 being cooled as an example.

The high-temperature and high-pressure refrigerant discharged by the operation of the compressor 1 releases heat by heat exchange with the air and the second suction line 19 at a relatively low temperature in the condenser 2 to be condensed and liquefied. The second capillary 8 through the electric valve 11
Leads to. After that, the pressure is reduced by the second capillary 8 and reaches the second evaporator 5. The operation of the second electric fan 14 actively exchanges heat with the air in the freezing chamber 6, and the refrigerant is removed by the second evaporator 5. The air that has been evaporated and heat-exchanged in the chamber 5 is discharged as lower-temperature air to cool the freezing compartment 6. The vaporized refrigerant reaches the second suction line 19. The relatively low temperature refrigerant absorbs heat by heat exchange with the relatively high temperature condenser 2 and is sucked into the compressor 1.

Since the relatively high-temperature refrigerant passing through the condenser can be cooled by the relatively low-temperature refrigerant passing through the second suction line, the amount of heat released from the condenser 2 increases, and the excess of the second capillary inlet is exceeded. The degree of cooling is increased, the refrigerating capacity can be improved, and the freezing room can be cooled more efficiently.

The refrigerant having a relatively low temperature in the second suction line 19 absorbs heat due to heat exchange with the condenser 2 which has a relatively high temperature, and cannot be completely evaporated in the second evaporator 5. Since the refrigerant evaporates in the second suction line 19, it is possible to reduce the liquid return that causes an increase in power consumption and damage to the compressor 1.

In this embodiment, the improvement of the cooling efficiency of the freezer compartment in the specification in which the second suction line 19 exchanges heat with the condenser 2 has been described. The same effect can be obtained when the refrigerating compartment 4 is cooled even in the replaced specification.

(Embodiment 7) The detailed description of the same components as those in Embodiment 1 is omitted, and the same reference numerals are given.

FIG. 11 is a longitudinal sectional view of a refrigerator according to the seventh embodiment of the present invention, and FIG. 12 is a transverse sectional view of the refrigerator according to the seventh embodiment of the present invention.

In FIGS. 11 and 12, reference numeral 25 denotes the machine room 15.
This is, for example, a resin-molded evaporating dish provided below the second suction line crawling inside.

In FIG. 11, reference numeral 26 denotes a resin-molded tub having a drain port 27 provided below the second evaporator 5, and the drain port 27 is connected to the evaporating dish 25.

With the above configuration, the frost adhering to the second evaporator 5 is defrosted, becomes defrost water, and is stored in the evaporating dish 25 through the drain port 27.

If the amount of circulating refrigerant in the system during cooling of the freezing chamber becomes excessive, the refrigerant that has not been completely evaporated in the second evaporator 5 returns to the compression state. When liquid return occurs, the piping temperature of the second suction line 19 decreases,
Dew condensation occurs on the surface of the pipe, causing water leakage at the refrigerator installation part, causing not only a quality problem but also a possibility of electric leakage, which is dangerous particularly when a flammable refrigerant is used. Therefore, by providing an evaporating dish below the second suction line 19, dew at the time of liquid return can be accumulated in the evaporating dish, and safety can be improved.

[0126]

The present invention is implemented in the state described above, and has the following effects.

A refrigerator box composed of a refrigerator compartment and a freezer compartment, a first evaporator in the refrigerator compartment, a second evaporator in the freezer compartment, a compressor, a condenser and a first evaporator are provided. A flow path control means, a first capillary, a first evaporator, a second flow path control means, a second capillary, a second evaporator, and a check valve are provided. A closed loop is formed by the flow path control means, the first capillary, and the first evaporator, and the second flow path control means, the first capillary, and the second evaporator are arranged in parallel with the first evaporator. The flow path control means, the second capillary, the second evaporator, and the check valve are connected, and the flow of the refrigerant is switched by the first and second flow path control means. , The compressor is operated in a state where both the first and second electric valves are closed for a predetermined time, and then the cooling of the refrigerator compartment is started. Than it is.

According to the present invention, after the freezer compartment cooling is completed, the compressor is operated in a state where the first flow path control means and the second flow path control means are closed for a predetermined time and the flow of the refrigerant is completely shut off. As a result, the pressure in the compressor becomes lower than that during normal operation, so that the refrigerant that has accumulated in the second evaporator can be expelled from the second evaporator to the compressor side. As a result, when the mode is switched to the refrigerator compartment cooling, sufficient refrigerant for cooling the refrigerator compartment is supplied to the first evaporator, so that the refrigerant circulation amount is not insufficient, and the refrigerator compartment can be efficiently cooled. Become.

In addition, since the refrigerant can be used efficiently, the amount of the refrigerant can be reduced, and when a flammable refrigerant is used, the risk of leakage of the refrigerant can be reduced.

When switching from freezing compartment cooling to refrigerating compartment cooling, the compressor is operated at a higher speed than during normal operation with both the first and second flow path control means closed for a predetermined time. Since the pressure inside the device becomes considerably lower than that during normal operation, the refrigerant that has accumulated in the second evaporator can be quickly expelled from the second evaporator to the compressor side. As a result, the time for operating the compressor with both the first and second flow path control means closed can be reduced, so that the temperature rise in the refrigerator compartment can be reduced, and the refrigerator compartment can be cooled more efficiently. It becomes possible.

[0131] The fins are arranged in parallel, and the heat transfer tubes have a structure in which a gas flows between the fins and the fins penetrate the fins so that the refrigerant does not flow from the inlet to the outlet in the direction opposite to the direction of gravity. Since it is equipped with a second evaporator, the flow path resistance in the second evaporator is reduced, and the refrigerant remaining in the second evaporator can be smoothly expelled to the compressor side, The time for operating the compressor with both the first and second flow path control means closed can be further reduced, and the refrigerator compartment can be cooled more efficiently.

During cooling of the freezing compartment, the flow resistance in the second evaporator is small, so that the oil returns to the compressor is improved. Oil accumulation can be prevented.

Further, the freezing compartment is disposed below the refrigerating compartment, and the pipe length of the second suction line can be shortened. As a result, the flow resistance of the second suction line decreases, Since the refrigerant remaining in the second evaporator can be more smoothly expelled to the compressor side,
The time for operating the compressor with both the first and second flow path control means closed can be further reduced, and the refrigerator compartment can be cooled more efficiently.

Also, after leaving the second evaporator, the second suction line is not raised along the back of the refrigerator, and the bottom of the refrigerator is crawled, and then connected to the compressor. The suction line that raised the back of the refrigerator for heat exchange with the piping structure that does not start by effectively using the bottom of the refrigerator can reduce the flow resistance of the second suction line, and the second evaporator Since the refrigerant staying in the inside can be more smoothly expelled to the compressor side, the time for operating the compressor with both the first and second flow path control means closed can be further reduced. Thus, the refrigerator compartment can be cooled more efficiently.

In addition, the second suction line exchanges heat with the condenser in the machine room disposed below the refrigerator, and the comparatively low temperature refrigerant passing through the second suction line passes through the condenser. Since a very high-temperature refrigerant can be cooled, the degree of supercooling at the entrance of the second capillary is increased, the refrigeration capacity can be improved, and the freezing chamber can be cooled more efficiently.

The refrigerant having a relatively low temperature in the second suction line absorbs heat by exchanging heat with the condenser having a relatively high temperature, and the refrigerant that cannot be completely evaporated in the second evaporator is the second refrigerant. Since evaporation takes place in the second suction line, it is possible to reduce liquid return, which causes an increase in power consumption and damage to the compressor.

Further, an evaporating dish is provided below the second suction line crawling in the machine room disposed below the refrigerator, and the amount of circulating refrigerant in the system becomes excessive when the freezing room is cooled. The relatively low-temperature refrigerant that could not evaporate completely in the evaporator returned to the compressor and returned to the compressor. Can be stored. As a result, it is possible to prevent water leakage from the refrigerator installation portion and prevent electric leakage, thereby improving safety particularly when a flammable refrigerant is used.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a refrigerator according to the first and second embodiments of the present invention.

FIG. 2 is a time chart of the refrigerator according to the first embodiment of the present invention.

FIG. 3 is a time chart of the refrigerator according to the second embodiment of the present invention.

FIG. 4 (a) is a schematic front view of a second evaporator according to a third embodiment of the present invention.

FIG. 5 is a schematic perspective view of a second evaporator in the embodiment.

FIG. 6 is a front view of a second evaporator in the embodiment.

FIG. 7 is a longitudinal sectional view of a refrigerator according to a fourth embodiment of the present invention.

FIG. 8 is a longitudinal sectional view of a refrigerator according to a fifth embodiment of the present invention.

FIG. 9 is a longitudinal sectional view of a refrigerator according to a sixth embodiment of the present invention.

FIG. 10 is a cross-sectional view of a refrigerator according to a sixth embodiment of the present invention.

FIG. 11 is a longitudinal sectional view of a refrigerator according to a seventh embodiment of the present invention.

FIG. 12 is a cross-sectional view of a refrigerator according to a seventh embodiment of the present invention.

FIG. 13 is a schematic diagram of a conventional refrigerator.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Compressor 2 Condenser 3 First evaporator 4 Refrigerating room 5 Second evaporator 6 Freezing room 7 First capillary 8 Second capillary 10 First flow control means 11 Second flow control means Reference Signs List 12 Refrigeration cycle 13 First electric fan 14 Second electric fan 15 Machine room 16 Compressor suction pipe 17 Compressor discharge pipe 18 First suction line 19 Second suction line 20 Check valve 21 Refrigerator box

Continued on the front page (72) Inventor Yasuki Hamano 4-2-5 Takaidahondori, Higashiosaka-shi, Osaka Matsushita Refrigerator Co., Ltd. F-term (reference) 3L045 AA03 BA01 BA03 CA02 CA03 DA02 EA01 GA07 HA02 HA07 JA14 JA16 LA05 LA09 LA17 MA02 PA01 PA04 PA05

Claims (7)

[Claims] A refrigerator box comprising a refrigerator compartment and a freezer compartment; a first evaporator disposed in the refrigerator compartment and a second evaporator disposed in the freezer compartment; And a condenser, a first flow path control means, a first capillary, the first evaporator, a second flow path control means, a second capillary, the second evaporator and a check valve, A closed loop is formed by the compressor, the condenser, the first flow path control means, the first capillary, and the first evaporator, and the first flow path control means and the first flow path Connect the second flow path control means, the second capillary, the second evaporator and the check valve so as to be in parallel with the capillary and the first evaporator,
The flow of the refrigerant is switched by the first and second flow path control means. When switching from freezing room cooling to refrigerator storage cooling, the first and second flow path control means are closed for a predetermined time. A refrigerator, wherein the refrigerator starts cooling after the compressor is operated. 2. When the compressor is switched from freezer compartment cooling to refrigerator compartment cooling, the compressor is operated at a higher speed than during normal operation while the first and second flow path control means are both closed for a predetermined period of time. 2. The refrigerator according to claim 1, wherein the refrigerator starts cooling at a rotation speed. 3. A fin in which a gas flows between the fins and a heat transfer tube which penetrates the fins and has a structure in which the refrigerant does not flow from the inlet to the outlet in the direction opposite to the direction of gravity. The refrigerator according to claim 1 or 2, further comprising a second evaporator. 4. The refrigerator according to claim 1, wherein the freezer compartment is provided below the refrigerator compartment. 5. A piping structure in which after leaving the second evaporator, the second suction line is not raised along the back of the refrigerator and the bottom of the refrigerator is crawled, and then connected to the compressor. The refrigerator according to any one of claims 1 to 4, wherein 6. The refrigerator according to claim 1, wherein the second suction line exchanges heat with a condenser in a machine room provided below the refrigerator. 7. The refrigerator according to claim 6, wherein an evaporating dish is provided below a second suction line that crawls in a machine room disposed below the refrigerator.