JP3410408B2 - refrigerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a refrigerator in which energy can be saved and the quantity of refrigerant can be reduced by cooling a refrigeration compartment and a freezing compartment while switching thereby enhancing the efficiency of a cooling system. SOLUTION: In a cooling cycle where the quantity of refrigerant required for cooling a refrigeration compartment 4 is lower as compared with the quantity of refrigerant required for cooling a freezing compartment 6, a compressor 1 is operated (pump down) under a state where the outlet side of a condenser 2 is closed by a channel control means 12 for a predetermined time immediately before cooling is switched from the freezing compartment 6 to the refrigeration compartment 4 and cooling of the refrigeration compartment 4 is started after refrigerant standing in a second evaporator 5 is purged to the condenser 2 side.

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 refrigerating compartment independently of each other, to improve efficiency, reduce the amount of refrigerant, and improve safety.

[0002]

2. Description of the Related Art FIG. 19 shows a cooling cycle diagram of a refrigerator disclosed in Japanese Patent Publication No. 62-22396, as an example of a conventional cooling cycle and a refrigerator.

Reference numeral 1 is a compressor, 2 is a condenser, 3 is a first evaporator arranged in a refrigerating compartment 4, and 5 is a second evaporator arranged in a freezing compartment 6. .

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

Reference numeral 10 is a first on-off valve provided on the downstream side of the refrigerant circuit of the first evaporator 3, and 11 is a second on-off valve provided on the upstream side of the refrigerant circuit of the second capillary 8. Is.

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

The operation of the refrigeration cycle is performed as follows. First, the refrigerant compressed by the compressor 1 is condensed and liquefied by 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, and is evaporated and vaporized, and then again flows into the compressor 1. Inhaled.

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

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

When the temperature detecting means of the refrigerating room 4 and the freezing room 6 detect a temperature increase of a predetermined value or more, the compressor 1 is started and the refrigerating cycle is operated. The first opening / closing valve 10 is opened and the second opening / closing valve 11 is closed until the temperature detecting means of the refrigerating chamber 4 becomes equal to or 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. The setting of the evaporation temperature of the refrigerating cycle at this time is -5 to 0 ° C. with respect to the temperature setting of the refrigerating chamber 4 of about 5 ° C.
The compressor can be operated with a coefficient of performance of 2 to 2.5 times the evaporation temperature of -25 ° C.

When the refrigerating chamber 4 is cooled and the temperature drops, and the temperature detecting means detects a temperature below a predetermined value, the first opening / closing valve 10
Is closed and the second on-off valve 11 is opened.

As a result, the refrigerant flows into the second evaporator 5, and the freezer compartment 6 is cooled. The evaporation temperature of the refrigerating cycle at this time is cooled at a normal evaporation temperature (-30 to -25 ° C) with respect to the temperature setting of the freezing chamber of about -18 ° C.

As described above, the refrigerating chamber 4 and the freezing chamber 6 are alternately cooled repeatedly by distributing the refrigerant supply time to the evaporator. Therefore, when the refrigerating chamber 4 is cooled, the first refrigerant is independently evaporated. By circulating it to the reactor, 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 made small, and operation is performed with a high coefficient of performance to improve efficiency. It is a thing.

Further, since the check valve 9 has a high evaporation temperature during cooling of the refrigerating chamber 4, it prevents the refrigerant from flowing into the second evaporator 5.

Further, when the freezing chamber 6 is cooled, the amount of the refrigerant is smaller than that during the cooling of the refrigerating chamber 4, so that the amount of the refrigerant is usually excessive. However, since the first opening / closing valve 10 is provided on the downstream side of the first evaporator 3 and is closed, it is possible to store the refrigerant in the first evaporator 3 and adjust the amount of the refrigerant.

[0017]

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

However, the evaporation temperature (−30 to −25 ° C.) of the second evaporator 5 arranged in the freezing chamber 6 is equal to that of the first evaporator 3 arranged in the refrigerating chamber 4. Temperature (-5 to 0 ° C)
Compared with, the temperature is considerably lower and the pressure is also lower.

While the refrigerating compartment 4 is being cooled, the temperature of the first evaporator 3 arranged in the refrigerating compartment 4 is -5 to 0 ° C.
Since the temperature in the freezer compartment 6 is as low as about -18 ° C, the temperature of the second evaporator 5 arranged in the freezer compartment 6 is also about -18 ° C.
Since the temperature of the second evaporator 5 is considerably lower than the temperature of the first evaporator 3, the pressure is also low, so that the refrigerant accumulated in the second evaporator 5 is It is difficult for the second evaporator 5 to flow out. As a result, a sufficient amount of refrigerant is not supplied to the first evaporator 3, the amount of refrigerant circulation becomes insufficient, and the cooling efficiency of the refrigerating chamber 4 decreases.

In particular, when the required refrigerant amount for cooling the refrigerating chamber 4 is equal to or larger than the required refrigerant amount for cooling the freezing chamber 6, the refrigerating chamber 4 is cooled when the refrigerating chamber 4 is cooled. Since the refrigerant accumulated in the low-temperature, low-pressure second evaporator 5 disposed inside 6 must be completely recovered from the first evaporator 3, sufficient refrigerant is supplied to the first evaporator 3. However, the refrigerant circulation amount becomes insufficient, and the cooling efficiency of the refrigerating chamber 4 tends to decrease.

Further, as a measure for preventing the cooling efficiency from decreasing due to the shortage of the circulating amount of the refrigerant when the refrigerating chamber 4 is cooled, the refrigerant is stored at the outlet side of the first evaporator 3 or the outlet side of the second evaporator 5. A method of providing a means and enclosing the refrigerant more than necessary is conceivable, but since the amount of the refrigerant existing in the cooling cycle increases in this method, when a flammable natural refrigerant is used, the risk of refrigerant leakage is high. There's a problem.

The present invention solves the above-mentioned conventional problems, and provides a refrigerator capable of energy saving by improving the efficiency of a cooling system which switches between cooling of a refrigerating room and a freezing room. The purpose is to

Further, from the above results, since the refrigerant can be efficiently used, the amount of the refrigerant can be reduced, and particularly when a flammable natural refrigerant (isobutane, propane, etc.) is used, the refrigerant leakage is caused by the reduction of the refrigerant amount. It is an object of the present invention to provide a refrigerator that can improve the safety of time.

[0024]

To achieve this object, a refrigerator according to the present invention comprises a low-pressure container type compressor, a condenser, a flow path control means, a first pressure reducing means, and a refrigerating chamber. A first evaporator provided, a first blower, a second depressurizer, a second evaporator provided in the freezer compartment, a second blower, and a check valve . A refrigeration cycle consisting of
A refrigerating-room-side cooling circuit is formed by the compressor, the condenser, the flow path control unit, the first decompression unit, and the first evaporator, which includes a flammable natural refrigerant enclosed in a refrigeration cycle. In addition, the second pressure reducing means and the second evaporator and the check valve are connected in parallel to the first pressure reducing means and the first evaporator, and the compressor and the A freezer compartment cooling circuit is formed by a condenser, the flow path control means, the second pressure reducing means, the second evaporator, and the check valve,
Independently of each other row Umono cooling of the freezing chamber and the refrigerating chamber by switching the flow of refrigerant to the cooling circuit by the flow path control means, the said first evaporator
The volume in the pipe is the volume in the pipe forming the second evaporator.
The amount of refrigerant required for the refrigerating compartment cooling circuit for cooling the refrigerating compartment is smaller than that for the refrigerating compartment side cooling circuit for cooling the refrigerating compartment. small comb as compared to, and retained in the second evaporator
If some of the refrigerant is recovered, it will be recovered by the first evaporator.
To ensure the required amount of refrigerant to cool the refrigerator compartment
Characterized in that the.

Further, from the cooling circuit on the freezing room side to the cooling on the refrigerating room side.
Just before switching to the circuit, the flow path control
Operate the compressor with the outlet side of the condenser closed by stages
Characterized in that it.

Further, a defrost heater for periodically defrosting the second evaporator is provided, and immediately before the cooling of the freezing compartment is switched to the cooling of the refrigerating compartment, the flow passage control means is used for a predetermined period of time to control the condenser. The defrost heater is energized when the compressor is operated with the outlet side closed.

Further, immediately before the cooling of the freezer compartment is switched to the cooling of the refrigerating compartment, when the compressor is operated with the outlet side of the condenser closed by the flow path control means for a predetermined time, the defrost heater is used. It is characterized by intermittently energizing.

Further, immediately before the cooling of the freezer compartment is switched to the cooling of the refrigerating compartment, when the compressor is operated with the outlet side of the condenser closed by the flow path control means for a predetermined time, the second blower It is characterized by driving means.

Further, the pressure reduction amount by the first pressure reducing means is 0.
It is characterized by being 2 MPa to 0.5 MPa.

Further, immediately before the cooling of the freezer compartment is switched to the cooling of the refrigerating compartment, the compressor is operated for a predetermined time while the outlet side of the condenser is closed by the flow path control means, and then the refrigerating compartment is cooled. When starting, the compressor is characterized by operating at a rotational speed higher than a normal rotational speed for a predetermined time.

Immediately before switching from cooling of the freezing compartment to cooling of the refrigerating compartment, after the compressor is operated for a predetermined time while the outlet side of the condenser is closed by the flow path control means,
When the cooling of the refrigerating room is started, the defrosting heater is energized for a predetermined time.

Immediately before the cooling of the freezer compartment is switched to the cooling of the refrigerating compartment, the compressor is operated for a predetermined time while the outlet side of the condenser is closed by the flow path control means,
When the cooling of the refrigerating room is started, the defrosting heater is intermittently energized for a predetermined time.

Further, immediately before the cooling of the freezing compartment is switched to the cooling of the refrigerating compartment, the compressor is operated for a predetermined time while the outlet side of the condenser is closed by the flow path control means, and then the refrigerating compartment is cooled. When starting, the second air blowing means is operated for a predetermined time.

[0034]

According to the present invention, it is possible to provide a refrigerator capable of saving energy by reducing the amount of refrigerant and improving the efficiency of a cooling system which switches cooling between a refrigerating room and a freezing room.

Further, from the above results, the refrigerant can be used efficiently, so that the amount of the refrigerant can be reduced, and especially when a flammable natural refrigerant is used, the reduction of the amount of the refrigerant enhances the safety at the time of refrigerant leakage. It is possible to provide a refrigerator that can.

[0037]

BEST MODE FOR CARRYING OUT THE INVENTION The invention according to claim 1 of the present invention is arranged in a low pressure container type compressor, a condenser, a flow path control means, a first pressure reducing means, and a refrigerating chamber. a first evaporator, the first blowing means, and a second pressure reducing means, and a second evaporator disposed in the freezing chamber, the more the second blowing means, a check valve refrigeration Cycle and seal in the refrigeration cycle
With a flammable natural refrigerant entered, together with the compressor, the condenser, the flow path control means, the first pressure reducing means and the first evaporator to form a refrigerating compartment side cooling circuit,
The second pressure reducing means, the second evaporator and the check valve are connected so as to be in parallel with the first pressure reducing means and the first evaporator, and the compressor and the condenser are connected. A cooling chamber side cooling circuit is formed by the flow path control means, the second pressure reducing means, the second evaporator, and the check valve, and the flow of refrigerant to each cooling circuit is controlled by the flow path control means. row independently of one another a cooling of the freezing chamber and the refrigerating chamber by switching Umono
And the capacity in the pipe that constitutes the first evaporator is
Small volume compared to the capacity in the piping that makes up the second evaporator
The amount of the refrigerant compares the amount of refrigerant required for the refrigerating compartment cooling circuit for cooling the refrigerating compartment with the amount of refrigerant required for the freezing compartment side cooling circuit for cooling the freezing compartment. /> small comb, part of the refrigerant staying in the second evaporator times
Once collected, cool the refrigerating compartment with the first evaporator.
It is characterized in that the amount of refrigerant required for cooling is secured . Further, the invention according to claim 2 is the cooling on the freezer compartment side.
Just before switching from the circuit to the refrigerating room side cooling circuit, at a predetermined time
During that time, the outlet side of the condenser is closed by the flow path control means.
It is characterized in that the compressor is operated in a closed state.

With the above configuration, immediately before the cooling of the freezer compartment is switched to the cooling of the refrigerating compartment, the compressor is operated for a predetermined time while the outlet side of the condenser is closed by the flow path control means to forcefully operate the compressor. By performing pump down in which the refrigerant is moved from the low pressure side to the high pressure side, the refrigerant that has accumulated in the low temperature and low pressure second evaporator can be expelled to the condenser side (high pressure side). In the cooling of the refrigerating chamber after pumping down, the refrigerant is quickly supplied to the first evaporator, so that the refrigerant circulation amount does not become insufficient and the cooling efficiency of the refrigerating chamber can be improved.

If the required amount of refrigerant for cooling the refrigerating chamber is smaller than that required for cooling the freezing chamber,
By recovering a part of the refrigerant that has accumulated in the low-temperature, low-pressure second evaporator, it is possible to secure the required amount of refrigerant for cooling the refrigerating chamber, so that the efficiency of pump down can be improved and the refrigerating chamber Energy can be saved by improving the cooling efficiency.

Further, from the above results, since the refrigerant can be efficiently used, the amount of the refrigerant can be reduced, and particularly when a flammable natural refrigerant, that is, a refrigerant such as isobutane or propane is used, the reduction of the refrigerant amount causes It is possible to enhance the safety when the refrigerant leaks.

[0041]

In the cooling system, the smaller the capacity of the pipe forming the evaporator is, the more the amount of required refrigerant tends to decrease. Therefore, the capacity of the pipe forming the first evaporator is smaller than that of the second evaporator. When the capacity is small compared to the capacity in the piping that constitutes the, the amount of refrigerant required to cool the refrigerating compartment tends to be smaller than the amount of refrigerant required to cool the freezing compartment, By recovering a part of the refrigerant that has accumulated in the low-pressure second evaporator, it is possible to secure the required amount of refrigerant for cooling the refrigerating chamber, which can improve the efficiency of pump down and the cooling efficiency of the refrigerating chamber. It is possible to save energy by improving.

According to a third aspect of the present invention, a defrosting heater for periodically defrosting the second evaporator is provided, and the flow is performed for a predetermined time immediately before switching from cooling the freezing chamber to cooling the refrigerating chamber. The defrost heater is energized when the compressor is operated (pump down) with the outlet side of the condenser closed by the path control means.

By energizing the defrost heater for defrosting the second evaporator at the time of pump down, it is possible to suppress the decrease in temperature and pressure of the second evaporator during pump down. It is possible to improve efficiency.

According to the fourth aspect of the invention, immediately before the cooling of the freezer compartment is switched to the cooling of the refrigerating compartment, the compressor is operated for a predetermined time while the outlet side of the condenser is closed by the flow passage control means ( When the pump is down), the defrost heater is intermittently energized.

By energizing the defrosting heater for defrosting the second evaporator at the time of pump down, it is possible to suppress the decrease in temperature and pressure of the second evaporator during pump down. It is possible to improve efficiency, but when the pump down works effectively without continuous energization during the pump down depending on the load condition, for example, when the temperature difference between the freezing room and the refrigerating room is small. There is. In such a case, it is possible to reduce power consumption by the defrost heater during pump down by intermittently energizing the defrost heater during pump down by, for example, duty control.

According to the fifth aspect of the invention, immediately before the cooling of the freezer compartment is switched to the cooling of the refrigerating compartment, the compressor is operated for a predetermined time while the outlet side of the condenser is closed by the flow passage control means ( The second blowing means is operated when the pump is down).

By operating the second blowing means during the pump down, it is possible to suppress the temperature and pressure drop of the second evaporator during the pump down, so that the efficiency of the pump down can be improved. Become.

The invention according to claim 6 is characterized in that the pressure reduction amount by the first pressure reducing means is 0.2 MPa to 0.5 MPa.

The decompression amount by the first decompression means is 0.2 MPa, which is smaller than the ordinary decompression amount (about 0.6 MPa).
By setting the pressure to 0.5 MPa, the resistance when the refrigerant passes through the first pressure reducing means is small, the refrigerant easily flows, and when the refrigerating chamber is cooled after the pump is down, the high pressure side (condenser side) is caused by the pump down. ), The refrigerant expelled to (4) rapidly moves to the first evaporator via the first pressure reducing means having a small resistance, so that the refrigerant circulation amount does not become insufficient and the cooling efficiency of the refrigerating chamber can be improved.

In the seventh aspect of the invention, immediately before the cooling of the freezer compartment is switched to the cooling of the refrigerating compartment, the compressor is operated for a predetermined time while the outlet side of the condenser is closed by the flow path control means ( When the cooling of the refrigerating chamber is started after the pump down), the compressor is operated at a rotation speed higher than the normal rotation speed for a predetermined time.

When cooling the refrigerating chamber after pumping down,
By operating the compressor at a higher rotational speed than the normal rotational speed for a specified time, a large amount of the refrigerant displaced to the high pressure side (condenser side) due to pump down is pushed out to the first evaporator with a strong force. As a result, it is possible to improve the cooling efficiency of the refrigerating compartment without causing a shortage of the refrigerant circulation amount.

In the eighth aspect of the invention, immediately before the cooling of the freezing compartment is switched to the cooling of the refrigerating compartment, the compressor is operated for a predetermined time while the outlet side of the condenser is closed by the flow path control means ( After the pump is down), when the cooling of the refrigerating chamber is started, the defrost heater is energized for a predetermined time.

When the amount of refrigerant required to cool the refrigerating compartment by pump down cannot be recovered from the low-temperature, low-pressure second evaporator, when the refrigerating compartment is cooled after pump down,
By energizing the defrost heater for a predetermined time, the temperature and pressure of the second evaporator can be increased during cooling of the refrigerating chamber, thus improving the efficiency of collecting the refrigerant accumulated in the second evaporator. Therefore, it is possible to provide the refrigerator in which the time for which the refrigerant circulation amount of the first evaporator is insufficient can be shortened and the cooling efficiency of the refrigerating room can be improved.

According to the ninth aspect of the present invention, immediately before the cooling of the freezer compartment is switched to the cooling of the refrigerating compartment, the compressor is operated for a predetermined time while the outlet side of the condenser is closed by the flow passage control means ( When the cooling of the refrigerating chamber is started after the pump down), the defrosting heater is energized intermittently for a predetermined time.

When the amount of refrigerant required to cool the refrigerating compartment by pumping down cannot be recovered from the low-temperature, low-pressure second evaporator, when cooling the refrigerating compartment after pumping down,
By energizing the defrost heater, the temperature and pressure of the second evaporator can be increased during the cooling of the refrigerating chamber, so that the efficiency of collecting the refrigerant staying in the second evaporator can be improved. , It is possible to shorten the time of the refrigerant circulation amount shortage of the first evaporator, but when cooling the refrigerating chamber after pump down depending on the load condition, for example, when the temperature difference between the freezing chamber and the refrigerating chamber is small. Even if the electricity is not continuously applied for a predetermined time, the time of insufficient circulation of the refrigerant may be sufficiently short. In such a case, it is possible to reduce power consumption by the defrost heater by intermittently energizing the defrost heater during cooling of the refrigerating chamber after pump down, for example, by duty control. .

According to the tenth aspect of the invention, immediately before the cooling of the freezer compartment is switched to the cooling of the refrigerating compartment, the compressor is operated for a predetermined time while the outlet side of the condenser is closed by the flow passage control means ( When the cooling of the refrigerating chamber is started after the pump down), the second blowing means is operated for a predetermined time.

When the amount of refrigerant required to cool the refrigerating compartment by pumping down cannot be recovered from the low-temperature, low-pressure second evaporator, when cooling the refrigerating compartment after pumping down,
By operating the second blowing means for a predetermined time, the temperature and pressure of the second evaporator can be increased during the cooling of the refrigerating chamber, so that the efficiency of collecting the refrigerant accumulated in the second evaporator can be improved. It is possible to provide a refrigerator in which the cooling efficiency of the refrigerating compartment can be improved by shortening the time for which the refrigerant circulation amount of the first evaporator is insufficient.

[0059]

[0060]

Embodiments of the present invention will be described below with reference to FIGS. 1 to 18. The same components as those of the conventional example are designated by the same reference numerals, and detailed description thereof will be omitted.

(Embodiment 1) FIG. 1 is a cooling cycle diagram of a refrigerator according to an embodiment of the present invention, FIG. 2 is a schematic sectional view of a flow path control means according to the embodiment, and FIG. 3 is the same embodiment. 5 is a characteristic diagram of the amount of refrigerant enclosed in the first evaporator according to FIG. 4, FIG. 4 is a characteristic diagram of the amount of enclosed refrigerant in the second evaporator according to the same embodiment, FIG.
3 is an operation time chart of the refrigerator according to the same embodiment.

Compressor 1, condenser 2, flow path control means 1
2, the first decompression means 7, the first evaporator 3 arranged in the refrigerating compartment 4, the first air blowing means 13, the second decompression means 8, and the freezing compartment 6. The second evaporator 5 provided, the second blowing means 14, and the check valve 9 are provided, and the compressor 1, the condenser 2, the first pressure reducing means 7, and the first evaporator 3 are provided. A refrigerating chamber side cooling circuit is formed and the second pressure reducing means 8, the second evaporator 5 and the check valve 9 are connected so as to be in parallel with the first pressure reducing means 7 and the first evaporator 3. Then, the compressor 1, the condenser 2, the second pressure reducing means 8, the second evaporator 5, and the check valve 9 form a freezer compartment cooling circuit.

A refrigerator box 15 has a refrigerating compartment 4 which is a relatively high temperature compartment in the upper part and a freezing compartment 6 which is a relatively low temperature compartment in the lower part, such as urethane. It is configured to insulate the surroundings with a heat insulating material. Items such as foods are taken in and out via a heat insulating door (not shown).

The compressor 1, the condenser 2, and the flow path control means 12 are used in the machine room 1 to reduce the number of pipe connection points in the refrigerator box 15 from the viewpoint of improving safety when using a flammable natural refrigerant.
6 are arranged.

The refrigerating chamber 4 and the freezing chamber 6 are respectively provided with temperature detecting means (not shown) for detecting the temperature inside the compartment, and the compressor 1, the flow path controlling means 12, the first air blowing means 13 and the second air blowing are provided. The control means (not shown) for controlling the means 14 is provided.

As shown in FIG. 2, the flow path control means 12 is a three-way valve, which shuts off the flow of the refrigerant from the condenser 2 to the second pressure reducing means 8 and allows the refrigerant to flow to the first pressure reducing means 7. The flow is opened (first state) to shut off the flow of the refrigerant from the condenser 2 to the first pressure reducing means 7 and the first position 17 forming the refrigerating chamber side cooling circuit, and the second pressure reducing means. The second position 18 which forms the freezer compartment side cooling circuit by opening the flow of the refrigerant to 8 (the second state) and the outlet side of the condenser 2 to close the first decompression means 7 and the first decompression means 7. It is provided with a third position 19 that shuts off both the flow of the refrigerant to the second pressure reducing means 8 and shuts off the high pressure side and the low pressure side of the cooling cycle (the third state). The seal member 21, which is eccentrically fixed to the rotary shaft 20, has a cylinder 2
The pipes connected to the respective positions are closed by rotationally moving in 2 and stopping at the first, second, and third positions, respectively. The rotation is performed by drive means and transmission means (not shown). Positioning at each position is controlled by, for example, a drive pulse of a pulse motor.

The required amount of refrigerant in the refrigerating compartment side cooling circuit for cooling the refrigerating compartment 4 will be described with reference to FIG.

In FIG. 3, for example, when the outside air temperature is about 30 ° C., the flow path control means 12 is set to the first state, a refrigerating compartment side cooling circuit for cooling the refrigerating compartment 4 is formed, and the compressor 1 and the first refrigerating compartment are formed. The refrigerant inlet temperature of the first evaporator 3 at the time of stability when the amount of refrigerant to be enclosed in the refrigerating chamber-side cooling circuit (refrigerant enclosure amount) is changed in a state in which one blower 13 is continuously operated, The relationship between the refrigerant outlet temperature and the temperature inside the refrigerator compartment 4 is shown.

When the refrigerant charge amount is 40 g, the refrigerant outlet temperature of the first evaporator 3 is higher than the refrigerant inlet temperature, and the refrigerant circulation amount is insufficient, so that the cooling efficiency of the refrigerating chamber 4 is low. The inside temperature of the refrigerating compartment 4 is also high.

When the refrigerant charge amount is 50 g, the refrigerant inlet temperature and the refrigerant outlet temperature of the first evaporator 3 are equal to each other, the refrigerant circulation amount is in a proper state, and the cooling efficiency of the refrigerating chamber 4 is good. The temperature inside the refrigerator compartment 4 is also low.

Generally, in order to prevent the liquid back phenomenon to the compressor 1 in a transient operation state such as when the compressor 1 is started, a refrigerant storage means is provided on the refrigerant outlet side of the first evaporator 3. It is provided. While the amount of refrigerant enclosed is 60g-80g,
Although the amount of refrigerant to be filled is in an overfilled state, the refrigerant inlet temperature and the refrigerant outlet temperature of the first evaporator 3 maintain the same temperature due to the storage effect (margin) by this refrigerant storage means.
The cooling efficiency of the refrigerating compartment 4 is good, and the temperature inside the refrigerating compartment 4 is kept low. When the amount of the refrigerant filled exceeds 90 g, there exists a refrigerant having a storage effect (margin) of the refrigerant storage means or more, and a liquid back phenomenon that the liquid refrigerant is sucked into the compressor 1 occurs, resulting in the first evaporation. The evaporation temperature of vessel 3 rises,
The cooling efficiency of the refrigerating compartment 4 also deteriorates.

The amount of enclosed refrigerant (50 g in this case) in a state where there is no excess or deficiency of the refrigerant circulation amount in the refrigerating compartment side cooling circuit for cooling the refrigerating compartment 4 is set as the required refrigerant quantity for cooling the refrigerating compartment 4. .

In FIG. 4, for example, when the outside air temperature is about 30 ° C., the flow path control means 12 is set to the second state to form the freezing compartment side cooling circuit for cooling the freezing compartment 6, the compressor 1 and the first compartment. Refrigerant inlet temperature of the second evaporator 5 at the stable time when the amount of refrigerant to be enclosed in the freezer compartment cooling circuit (refrigerant enclosure amount) is changed in a state in which the second blowing means 14 is continuously operated, The relationship between the refrigerant outlet temperature and the temperature inside the freezer compartment 6 is shown.

When the refrigerant charge amount is 70 g, the refrigerant outlet temperature of the second evaporator 5 is higher than the refrigerant inlet temperature, and the refrigerant circulation amount is insufficient, so that the cooling efficiency of the freezer compartment 5 is low. The temperature inside the freezer compartment 5 is also high.

When the refrigerant charge amount is 80 g, the refrigerant inlet temperature and the refrigerant outlet temperature of the second evaporator 5 become equal to each other, the refrigerant circulation amount is not excessive, and the cooling efficiency of the freezer compartment 6 is good. The temperature inside the freezer compartment 6 is also low.

Generally, in order to prevent a liquid back phenomenon to the compressor 1 in a transient operation state such as when the compressor 1 is started, a refrigerant storage means is provided on the refrigerant outlet side of the second evaporator 5. It is provided. While the amount of enclosed refrigerant is between 90 g and 110 g, the amount of enclosed refrigerant is over-enclosed, but due to the storage effect (margin) of this refrigerant storage means, the refrigerant inlet temperature and the refrigerant outlet of the second evaporator 5 The same temperature is maintained, the cooling efficiency of the freezing compartment 6 is good, and the internal temperature of the freezing compartment 6 is kept low. When the amount of the filled refrigerant exceeds 120 g, there is more refrigerant than the storage effect (margin) by the refrigerant storage means, which causes a liquid back phenomenon in which the liquid refrigerant is sucked into the compressor 1 and the second evaporation. The evaporation temperature of the container 5 rises and the cooling efficiency of the freezer compartment 6 deteriorates.

The amount of enclosed refrigerant (80 g in this case) in a state in which there is no excess or deficiency of the refrigerant circulation amount in the freezing compartment side cooling circuit for cooling the freezing compartment 6 is the required amount of refrigerant for cooling the freezing compartment 6. .

As described above, the required refrigerant amount for cooling the refrigerating chamber 4 (50 g in this example) is smaller than the required refrigerant amount for cooling the freezing chamber 6 (80 g in this example). Characterize.

With respect to the refrigerator configured as described above,
The timing of cooling the refrigerating room 4 and the freezing room 6 will be described based on the time chart of FIG.

During cooling of the freezing compartment 6, the flow path control means 12 is in the second state, the refrigerant flows to the second evaporator 5, and the second blowing means 14 is operating.

The high-temperature and high-pressure refrigerant discharged by the operation of the compressor 1 is condensed and liquefied by the condenser 2, and the flow path control means 1
After being depressurized by the second depressurizing means 8 via 2, it flows into the second evaporator 5, and by exchanging heat with the air in the freezing compartment 6 by the operation of the second air blowing means 14, The refrigerant in the second evaporator 5 is vaporized and vaporized, and the heat-exchanged air becomes cooler air to cool the freezer compartment 6.

When the temperature detecting means of the refrigerating compartment 4 detects that the temperature exceeds the predetermined temperature set in advance during the cooling of the freezing compartment 6, the flow path controlling means 12 becomes the third state and the condenser 2
The exit side of is closed (T01).

At this time, the compressor 1 is operated so that the high pressure side and the low pressure side of the cooling cycle are cut off, and the first blower means 13 and the second blower means 1 are operated.
4 is stopped.

After pumping down for a predetermined time (Ta0), the flow path control means 12 enters the first state, the refrigerant flows into the first evaporator 3, and the first blowing means 13 is operated (T
02).

The refrigerant is decompressed by the first decompression means 7 via the compressor 1, the condenser 2 and the flow path control means 12, then flows into the first evaporator 3, and the first blowing means 13 is provided. By exchanging heat with the air in the refrigerating compartment 4, the refrigerant in the first evaporator 3 is evaporated and vaporized, and the heat-exchanged air becomes cooler air to cool the refrigerating compartment 4. .

When the temperature detecting means in the freezer compartment 6 detects that the temperature exceeds the preset temperature while the refrigerating compartment 4 is being cooled, the flow path control means 12 is in the second state and the second evaporator is set. Refrigerant flows in 5, the first air blower 13 is stopped, the second air blower 14 is operated, and cooling of the freezer compartment 6 is started (T03).

The refrigerant is decompressed by the second decompression means 8 via the compressor 1, the condenser 2 and the second on-off valve 11, and then flows into the second evaporator 5, where the second blowing means is provided. By performing heat exchange with the air in the freezer compartment 6 by the operation of 14, the refrigerant in the second evaporator 5 is vaporized and evaporated, and the heat-exchanged air becomes cooler air to cool the freezer compartment 6. To do.

The above operation is repeated to repeat the flow path control means 12
The flow of the refrigerant is switched to switch the refrigerating chamber 4 and the freezing chamber 6 alternately, and when the temperature detecting means of the refrigerating chamber 4 and the freezing chamber 6 detects that the temperature is lower than a preset predetermined temperature, the flow path control is performed. The means becomes the first state, both the first air blowing means 13 and the second air blowing means 14 are stopped, and the compressor 1 is stopped (T04).

As described above, immediately before the cooling of the freezer compartment 6 is switched to the cooling of the refrigerating compartment 4, the flow path control means 12 is set to the third state and the compressor 2 is closed with the outlet side of the condenser 2 closed. By driving pump 1 to forcibly move the refrigerant from the low pressure side to the high pressure side, the refrigerant accumulated in the second evaporator 5 is expelled to the condenser 2 side (high pressure side). Is possible. After pumping down, by setting the flow path control means 12 to the first state, the refrigerant is quickly supplied to the first evaporator 3, so that the refrigerant circulation amount does not become insufficient and the refrigerating chamber 4 is efficiently cooled. It becomes possible to do.

If the amount of refrigerant required for cooling the refrigerating chamber 4 is smaller than the amount of refrigerant required for cooling the freezing chamber 6, a part of the refrigerant accumulated in the low-temperature, low-pressure second evaporator 5 is recovered. By doing so, the required amount of refrigerant for cooling the refrigerating chamber 4 can be secured, so that the efficiency of pump down can be improved, and the cooling efficiency of the refrigerating chamber 4 can be improved, thus enabling energy saving.

Although the flow path control means 12 is a three-way valve, the same effect can be obtained by installing a two-way valve on the inlet side of each of the first pressure reducing means 7 and the second pressure reducing means 8.

(Second Embodiment) FIG. 6A is a front view of a first evaporator according to another embodiment, and FIG. 6B is a front view of a second evaporator according to the same embodiment. is there.

As shown in FIG. 6, the length of the pipe forming the first evaporator 3 is L1, the inner diameter is D1, the internal volume is V1, and the length of the pipe forming the second evaporator 5 is When L2, the inner diameter is D2, and the internal volume is V2, the internal volumes of the pipes forming the first evaporator 3 and the second evaporator 5 are V1 = 1, respectively.
/ 4πD1 ² L1, V2 = 1 / 4πD2 ² L2, and the internal volume V1 of the pipe of the first evaporator 3 and the internal volume V2 of the pipe of the second evaporator 5 are V1 <V2. Has been done.

In the cooling system, the smaller the capacity of the pipe forming the evaporator is, the more the amount of required refrigerant tends to decrease. Therefore, the capacity of the pipe forming the first evaporator 3 becomes smaller than that of the second evaporator 5. When the capacity is small compared to the capacity in the piping that constitutes, the amount of refrigerant required to cool the refrigerating chamber 4 tends to be smaller than the amount of refrigerant required to cool the freezing chamber 6, By recovering a part of the refrigerant that has accumulated in the low-temperature, low-pressure second evaporator 5, the amount of refrigerant necessary for cooling the refrigerating chamber 4 can be secured, and therefore the efficiency of pump down can be improved. Energy can be saved by improving the cooling efficiency of the refrigerator compartment 4.

Further, from the above results, since the refrigerant can be efficiently used, the amount of the refrigerant can be reduced. Especially when a flammable natural refrigerant (isobutane, propane, etc.) is used, the amount of the refrigerant can be reduced to prevent the refrigerant leakage. It is possible to improve the safety of time.

(Third Embodiment) FIG. 7 is a cooling cycle diagram of a refrigerator according to another embodiment of the present invention, and FIG. 8 is an operation time chart of the refrigerator according to the same embodiment.

Reference numeral 23 is a defrost heater for periodically defrosting the second evaporator 5.

With respect to the refrigerator configured as described above,
The timing of cooling the refrigerating room 4 and the freezing room 6 will be described based on the time chart of FIG.

When the temperature detecting means of the refrigerating compartment 4 detects that the temperature exceeds the preset predetermined temperature during the cooling of the freezing compartment 6, the flow path controlling means 12 becomes the third state and the condenser 2
The exit side of is closed (T11).

At this time, the compressor 1 is in operation (pump down) with the high pressure side and the low pressure side of the cooling cycle cut off, and the first blowing means 13 and the second blowing means 14 are stopped. The defrost heater 23 is energized.

After pumping down for a predetermined time (Ta1), energization of the defrost heater 23 is terminated, and the flow path control means 1
2 becomes the first state, the refrigerant flows into the first evaporator 3, the first blower 13 is operated, and cooling of the refrigerating chamber 4 is started (T12).

When the temperature detecting means in the freezer compartment 6 detects that the temperature exceeds the preset temperature while the refrigerating compartment 4 is being cooled, the flow path control means 12 is set to the second state and the second evaporator is set. Refrigerant flows in 5, the first blower 13 is stopped, the second blower 14 is operated, and cooling of the freezer compartment 6 is started (T13).

The above operation is repeated to repeat the flow path control means 12
The flow of the refrigerant is switched to switch the refrigerating chamber 4 and the freezing chamber 6 alternately, and when the temperature detecting means of the refrigerating chamber 4 and the freezing chamber 6 detects that the temperature is lower than a preset predetermined temperature, the flow path control is performed. The means becomes the first state, both the first blowing means 13 and the second blowing means 14 are stopped, and the compressor 1 is stopped (T14).

As described above, by energizing the defrost heater 23 at the time of pump down, it is possible to suppress a decrease in temperature and pressure of the second evaporator 5 during pump down, so that pump down efficiency is improved. Energy can be saved by improving the cooling efficiency of the refrigerating chamber 4.

Further, since the refrigerant can be efficiently used, the amount of the refrigerant can be reduced, and particularly when a flammable natural refrigerant (isobutane, propane, etc.) is used, the reduction of the amount of the refrigerant ensures safety at the time of refrigerant leakage. It becomes possible to raise.

(Embodiment 4) FIG. 9 is an operation time chart of a refrigerator according to another embodiment of the present invention.

The timing of cooling the refrigerating room 4 and the freezing room 6 will be described with reference to the time chart of FIG.

When the temperature detecting means in the refrigerating compartment 4 detects that the temperature exceeds the preset predetermined temperature while the freezing compartment 6 is being cooled, the flow path controlling means 12 enters the third state.
The exit side of is closed (T21).

At this time, the compressor 1 is in operation (pump down) with the high pressure side and the low pressure side of the cooling cycle cut off, and the first blower 13 and the second blower 14 are stopped. The defrosting heater 23 is energized intermittently by duty control or the like.

After the pump is down for a predetermined time (Ta2), the energization of the defrost heater 23 is terminated, and the flow path control means 1
2 becomes the first state, the refrigerant flows into the first evaporator 3, the first blower 13 is operated, and cooling of the refrigerating chamber 4 is started (T22).

When the temperature detecting means of the freezing compartment 6 detects that the temperature exceeds the preset temperature while the refrigerating compartment 4 is being cooled, the flow path controlling means 12 is set to the second state and the second evaporator is set. Refrigerant flows through 5, the first blower 13 is stopped, the second blower 14 is operated, and cooling of the freezer compartment 6 is started (T23).

The above operation is repeated to repeat the flow path control means 12
The flow of the refrigerant is switched to switch the refrigerating chamber 4 and the freezing chamber 6 alternately, and when the temperature detecting means of the refrigerating chamber 4 and the freezing chamber 6 detects that the temperature is lower than a preset predetermined temperature, the flow path control is performed. The means becomes the first state, both the first air blowing means 13 and the second air blowing means 14 are stopped, and the compressor 1 is stopped (T24).

By energizing the defrosting heater 23 when the pump is down, it is possible to suppress a decrease in the temperature and pressure of the second evaporator 5 during the pump down, so that it is possible to improve the efficiency of the pump down. However, for example, when the temperature difference between the freezer compartment 6 and the refrigerator compartment 4 is small,
Depending on the load condition, pump down may work effectively without continuous energization during pump down. In such a case, by energizing the defrost heater 23 during pump down intermittently by, for example, duty control, it is possible to reduce power consumption by the defrost heater 23 during pump down. .

Further, since the refrigerant can be efficiently used, the amount of the refrigerant can be reduced, and particularly when a flammable natural refrigerant (isobutane, propane, etc.) is used, the reduction of the amount of the refrigerant ensures safety at the time of refrigerant leakage. It becomes possible to raise.

(Fifth Embodiment) FIG. 10 is an operation time chart of a refrigerator according to another embodiment of the present invention.

The timing of cooling the refrigerator compartment 4 and the freezer compartment 6 will be described with reference to the time chart of FIG.

When the temperature detecting means of the refrigerating compartment 4 detects that the temperature exceeds the predetermined temperature set during the cooling of the freezing compartment 6, the flow path controlling means 12 becomes the third state and the condenser 2
The outlet side of is closed (T31).

At this time, the compressor 1 is in operation (pump down) with the high pressure side and the low pressure side of the cooling cycle cut off, the first blowing means 13 is stopped, and the second blowing means 14 is operated. Is driving.

After pumping down for a predetermined time (Ta3), the flow path control means 12 enters the first state, the refrigerant flows into the first evaporator 3, the first blower means 13 is operated, and the second The air blowing means 14 is stopped and cooling of the refrigerating compartment 4 is started (T32).

When the temperature detecting means in the freezer compartment 6 detects that the temperature exceeds the preset temperature while the refrigerating compartment 4 is being cooled, the flow path control means 12 is in the second state and the second evaporator is set. Refrigerant flows into 5, the first air blower 13 is stopped, the second air blower 14 is operated, and cooling of the freezer compartment 6 is started (T33).

The above operation is repeated to repeat the flow path control means 12
The flow of the refrigerant is switched to switch the refrigerating chamber 4 and the freezing chamber 6 alternately, and when the temperature detecting means of the refrigerating chamber 4 and the freezing chamber 6 detects that the temperature is lower than a preset predetermined temperature, the flow path control is performed. The means becomes the first state, both the first air blowing means 13 and the second air blowing means 14 are stopped, and the compressor 1 is stopped (T34).

When the pump is down, the second blowing means 14 is operated so that the second evaporator 5 during the pump down is operated.
Since it is possible to prevent the temperature and pressure from decreasing, the efficiency of pump down can be improved, and the cooling efficiency of the refrigerating chamber 4 can be improved to save energy.

Further, since the refrigerant can be efficiently used, the amount of the refrigerant can be reduced. Particularly, when a flammable natural refrigerant (isobutane, propane, etc.) is used, the reduction of the refrigerant amount reduces the safety at the time of refrigerant leakage. It becomes possible to raise.

(Sixth Embodiment) FIG. 11 is a cooling cycle diagram of a refrigerator according to another embodiment of the present invention, and FIG. 12 is an operation time chart of the refrigerator according to the same embodiment.

As shown in FIG. 11, the pressure reduction amount R1 by the first pressure reduction means 7 is 0.2 MPa to 0.5 MPa, and the pressure reduction amount R2 by the second pressure reduction means 8, which is a normal pressure reduction amount, is 0.
The pressure is about 6 MPa, and R1 <R2.

The timing of cooling the refrigerator compartment 4 and the freezer compartment 6 will be described with reference to the time chart of FIG.

When the temperature detecting means of the refrigerating compartment 4 detects that the temperature exceeds the predetermined temperature set during the cooling of the freezing compartment 6, the flow path controlling means 12 enters the third state.
The exit side of is closed (T41).

At this time, the compressor 1 is in operation (pump down) with the high pressure side and the low pressure side of the cooling cycle cut off, and the first blower 13 and the second blower 14 are stopped. ing.

After pumping down for a predetermined time (Ta4), the flow path control means 12 enters the first state, the refrigerant flows into the first evaporator 3, the first air blowing means 13 is operated, and the refrigerating chamber is operated. The cooling of No. 4 is started (T42).

When the temperature detecting means in the freezer compartment 6 detects that the temperature exceeds the preset temperature while the refrigerating compartment 4 is being cooled, the flow path control means 12 is in the second state and the second evaporator is set. Refrigerant flows through 5, the first blower 13 is stopped, the second blower 14 is operated, and cooling of the freezer compartment 6 is started (T43).

The above operation is repeated to repeat the flow path control means 12
The flow of the refrigerant is switched to switch the refrigerating chamber 4 and the freezing chamber 6 alternately, and when the temperature detecting means of the refrigerating chamber 4 and the freezing chamber 6 detects that the temperature is lower than a preset predetermined temperature, the flow path control is performed. The means becomes the first state, both the first air blowing means 13 and the second air blowing means 14 are stopped, and the compressor 1 is stopped (T4).

By setting the decompression amount by the first decompression means 7 to 0.2 MPa to 0.5 MPa which is smaller than the usual decompression amount (about 0.6 MPa) like the second decompression means 8, the first refrigerant is made to flow. The resistance when passing through the pressure reducing means 7 is small,
When the refrigerating chamber 4 is cooled after the pump down because the refrigerant easily flows, the refrigerant driven to the high pressure side (condenser side) by the pump down passes through the first pressure reducing means 7 having a low resistance to the first pressure reducing means 7. Since the refrigerant quickly moves to the evaporator 3, the refrigerant circulation amount does not become insufficient, and the energy efficiency can be saved by improving the cooling efficiency of the refrigerating chamber 4.

Further, since the refrigerant can be efficiently used, the amount of the refrigerant can be reduced. Especially, when a flammable natural refrigerant (isobutane, propane, etc.) is used, the reduction in the amount of the refrigerant ensures safety at the time of refrigerant leakage. It becomes possible to raise.

The decompression amount of the decompression means here is 1.2 MPa (12 kgf) by nitrogen gas at the inlet of the decompression means.
-The pressure difference (differential pressure) between the inlet and the outlet of the pressure reducing means when a pressure of cm ² G) is applied.

Further, the pressure reduction amount is 0.2 MPa to 0.5 MP.
In the state of a, the flow rate of nitrogen gas by the pressure reducing means is 12 L.
/ Min to 30 L / min.

(Embodiment 7) FIG. 13 is a cooling cycle diagram of a refrigerator according to another embodiment of the present invention, and FIG. 14 is an operation time chart of the refrigerator according to the embodiment.

Reference numeral 24 is a variable capacity compressor.

When the temperature detecting means of the refrigerating compartment 4 detects that the temperature exceeds the predetermined temperature set during the cooling of the freezing compartment 6, the flow path controlling means 12 becomes the third state and the condenser 2
The exit side of is closed (T51).

At this time, the compressor 1 is in operation (pump down) with the high pressure side and the low pressure side of the cooling cycle cut off, and the first blower 13 and the second blower 14 are stopped. ing.

After pumping down for a predetermined time (Ta5), the flow path control means 12 is in the first state, the refrigerant flows into the first evaporator 3, the first air blowing means 13 is operated, and the refrigerating chamber is operated. The cooling of No. 4 is started (T52).

At the same time when the cooling of the refrigerating chamber is started, the compressor 1 is rotated at a rotational speed higher than the normal rotational speed for a predetermined time (Tb
Drive during 0).

When the temperature detecting means of the freezer compartment 6 detects that the temperature exceeds the preset temperature while the refrigerating compartment 4 is being cooled, the flow path control means 12 is in the second state and the second evaporator is set. Refrigerant flows through 5, the first air blower 13 is stopped, the second air blower 14 is operated, and cooling of the freezer compartment 6 is started (T53).

The above operation is repeated to repeat the flow path control means 12
The flow of the refrigerant is switched to switch the refrigerating chamber 4 and the freezing chamber 6 alternately, and when the temperature detecting means of the refrigerating chamber 4 and the freezing chamber 6 detects that the temperature is lower than a preset predetermined temperature, the flow path control is performed. The means becomes the first state, both the first air blowing means 13 and the second air blowing means 14 are stopped, and the compressor 1 is stopped (T54).

When the refrigerating chamber 4 is cooled after the pump is down, the compressor 1 is driven to a high speed side (condenser side) by pumping down by operating the compressor 1 at a higher speed than the normal speed for a predetermined time. Since a large amount of the refrigerant can be pushed out to the first evaporator 3 with a strong force, the refrigerant circulation amount does not become insufficient, and the cooling efficiency of the refrigerating chamber 4 is improved, so that energy can be saved.

Further, since the refrigerant can be efficiently used, the amount of the refrigerant can be reduced. Particularly, when a flammable natural refrigerant (isobutane, propane, etc.) is used, the reduction of the amount of the refrigerant ensures safety at the time of refrigerant leakage. It becomes possible to raise.

(Embodiment 8) FIG. 15 is an operation time chart of a refrigerator according to another embodiment of the present invention.

The timing of cooling the refrigerator compartment 4 and the freezer compartment 6 will be described with reference to the time chart of FIG.

When the temperature detecting means of the refrigerating compartment 4 detects that the temperature exceeds the preset temperature while the freezing compartment 6 is being cooled, the flow path controlling means 12 becomes the third state and the condenser 2
The outlet side of is closed (T61).

At this time, the compressor 1 is operating (pump down) with the high pressure side and the low pressure side of the cooling cycle disconnected, and the first blower 13 and the second blower 14 are stopped. ing.

After pumping down for a predetermined time (Ta6), the flow path control means 12 enters the first state, the refrigerant flows into the first evaporator 3, the first blower means 13 is operated, and the refrigerating chamber is operated. The cooling of No. 4 is started (T62).

At the same time when the cooling of the refrigerating chamber is started, the defrosting heater 23 is energized for a predetermined time (Tb1).

When the temperature detecting means of the freezer compartment 6 detects that the temperature exceeds the preset predetermined temperature while the refrigerating compartment 4 is being cooled, the flow path control means 12 becomes the second state and the second evaporator. Refrigerant flows into 5, the first blower 13 is stopped, the second blower 14 is operated, and cooling of the freezer compartment 6 is started (T63).

The above operation is repeated to repeat the flow path control means 12
The flow of the refrigerant is switched to switch the refrigerating chamber 4 and the freezing chamber 6 alternately, and when the temperature detecting means of the refrigerating chamber 4 and the freezing chamber 6 detects that the temperature is lower than a preset predetermined temperature, the flow path control is performed. The means becomes the first state, both the first blower 13 and the second blower 14 are stopped, and the compressor 1 is stopped (T64).

When the amount of refrigerant required to cool the refrigerating compartment 4 by pumping down cannot be completely recovered from the low-temperature, low-pressure second evaporator 5, when the refrigerating compartment 4 is cooled after the pumping down, a predetermined time is required. By energizing the defrost heater 23 during that period, the temperature and pressure of the second evaporator 5 can be increased during the cooling of the refrigerating chamber 4, so that the efficiency of collecting the refrigerant accumulated in the second evaporator 5 can be improved. Can be improved, the time for which the refrigerant circulation amount of the first evaporator 3 is insufficient and the cooling efficiency of the refrigerating chamber 4 are improved, and energy can be saved.

Further, since the refrigerant can be efficiently used, the amount of the refrigerant can be reduced. Especially, when a flammable natural refrigerant (isobutane, propane, etc.) is used, by reducing the amount of the refrigerant, safety at the time of refrigerant leakage can be improved. It becomes possible to raise.

(Ninth Embodiment) FIG. 16 is an operation time chart of a refrigerator according to another embodiment of the present invention.

The timing of cooling the refrigerator compartment 4 and the freezer compartment 6 will be described with reference to the time chart of FIG.

When the temperature detecting means of the refrigerating compartment 4 detects that the temperature exceeds the preset temperature during the cooling of the freezing compartment 6, the flow path controlling means 12 becomes the third state and the condenser 2
The exit side of is closed (T71).

At this time, the compressor 1 is in operation (pump down) with the high pressure side and the low pressure side of the cooling cycle cut off, and the first blowing means 13 and the second blowing means 14 are stopped. ing.

After pumping down for a predetermined time (Ta7), the flow path control means 12 enters the first state, the refrigerant flows into the first evaporator 3, the first air blowing means 13 is operated, and the refrigerating chamber is operated. The cooling of No. 4 is started (T72).

At the same time when the cooling of the refrigerating chamber is started, the defrosting heater 23 is intermittently energized by a duty control or the like for a predetermined time (Tb2).

When the temperature detecting means in the freezer compartment 6 detects that the temperature exceeds the preset temperature while the refrigerating compartment 4 is being cooled, the flow path control means 12 is in the second state and the second evaporator is set. Refrigerant flows into 5, the first blower 13 is stopped, the second blower 14 is operated, and cooling of the freezer compartment 6 is started (T73).

The above operation is repeated to repeat the flow path control means 12
The flow of the refrigerant is switched to switch the refrigerating chamber 4 and the freezing chamber 6 alternately, and when the temperature detecting means of the refrigerating chamber 4 and the freezing chamber 6 detects that the temperature is lower than a preset predetermined temperature, the flow path control is performed. The means becomes the first state, both the first blower 13 and the second blower 14 are stopped, and the compressor 1 is stopped (T74).

When the amount of refrigerant required to cool the refrigerating compartment 4 by pumping down cannot be recovered from the low-temperature, low-pressure second evaporator 5, defrosting is performed when cooling the refrigerating compartment 4 after pumping down. By energizing the heater 23, the refrigerator compartment 4
Since the temperature and the pressure of the second evaporator 5 can be increased during the cooling of the second evaporator, the efficiency of collecting the refrigerant accumulated in the second evaporator 5 can be improved, and the refrigerant circulation of the first evaporator can be improved. It is possible to shorten the time of the amount shortage, but depending on the load condition, for example, when the temperature difference between the freezing compartment 6 and the refrigerating compartment 4 is small, the refrigerating compartment 4 may be cooled for a predetermined time depending on the load condition. Even if the electricity is not continuously applied, the shortage time of the refrigerant circulation amount may be sufficiently short. In such a case, the defrost heater 2 when cooling the refrigerating chamber 4 after pump down
It is possible to reduce the power consumption by the defrost heater 23 by intermittently energizing 3 by, for example, duty control.

Further, since the refrigerant can be efficiently used, the amount of the refrigerant can be reduced, and particularly when a flammable natural refrigerant (isobutane, propane, etc.) is used, the reduction in the amount of the refrigerant ensures safety at the time of refrigerant leakage. It becomes possible to raise.

(Embodiment 10) FIG. 17 is an operation time chart of a refrigerator according to another embodiment of the present invention.

Timing of cooling the refrigerating room 4 and the freezing room 6 will be described with reference to the time chart of FIG.

When the temperature detecting means of the refrigerating compartment 4 detects that the temperature exceeds the preset temperature during cooling of the freezing compartment 6, the flow path controlling means 12 enters the third state.
The exit side of is closed (T81).

At this time, the compressor 1 is in operation (pump down) with the high pressure side and the low pressure side of the cooling cycle cut off, and the first blower 13 and the second blower 14 are stopped. ing.

After pumping down for a predetermined time (Ta8), the flow path control means 12 enters the first state, the refrigerant flows into the first evaporator 3, the first air blowing means 13 is operated, and the refrigerating chamber is operated. The cooling of No. 4 is started (T82).

At the same time when the cooling of the refrigerating room is started, the second blowing means 14 is operated for a predetermined time (Tb3).

When the temperature detecting means of the freezer compartment 6 detects that the temperature exceeds the preset predetermined temperature while the refrigerating compartment 4 is being cooled, the flow path control means 12 becomes the second state and the second evaporator. Refrigerant flows into 5, the first blower 13 is stopped, the second blower 14 is operated, and cooling of the freezer compartment 6 is started (T83).

The above operation is repeated to repeat the flow path control means 12
The flow of the refrigerant is switched to switch the refrigerating chamber 4 and the freezing chamber 6 alternately, and when the temperature detecting means of the refrigerating chamber 4 and the freezing chamber 6 detects that the temperature is lower than a preset predetermined temperature, the flow path control is performed. The means becomes the first state, both the first blowing means 13 and the second blowing means 14 are stopped, and the compressor 1 is stopped (T84).

When the amount of refrigerant required to cool the refrigerating compartment 4 by pumping down cannot be completely recovered from the low-temperature, low-pressure second evaporator 5, when the refrigerating compartment 4 is cooled after the pumping down, a predetermined time is required. By operating the second blower 14 during that period, the temperature and pressure of the second evaporator 5 can be increased during the cooling of the refrigerating chamber 4, so that the refrigerant accumulated in the second evaporator 5 is recovered. Efficiency can be improved, the time for which the circulation amount of the refrigerant in the first evaporator 5 is insufficient can be shortened, and the cooling efficiency of the refrigerating chamber 4 can be improved, whereby energy can be saved.

Further, since the refrigerant can be efficiently used, the amount of the refrigerant can be reduced. Particularly, when a flammable natural refrigerant (isobutane, propane, etc.) is used, the reduction in the amount of the refrigerant ensures safety at the time of refrigerant leakage. It becomes possible to raise.

(Embodiment 11) FIG. 18 is a cooling cycle diagram of a refrigerator according to another embodiment of the present invention.

Reference numeral 25 is a low-pressure container type compressor.

An unillustrated flammable natural refrigerant (isobutane, propane, etc.) is used as the refrigerant of the cooling cycle.

The amount of refrigerant can be reduced by improving the efficiency of pump down and the cooling efficiency of the refrigerating chamber 4, and particularly when a flammable natural refrigerant (isobutane or propane) is used, the amount of refrigerant can be reduced. As a result, it is possible to enhance the safety when the refrigerant leaks.

[0181]

As described above, according to the present invention, it is possible to provide a refrigerator capable of saving energy by reducing the amount of refrigerant and improving the efficiency of a cooling system which switches between cooling of a refrigerating room and a freezing room. You can

Further, from the above results, since the refrigerant can be efficiently used, the amount of the refrigerant can be reduced. Especially, when a flammable natural refrigerant (isobutane, propane, etc.) is used, the refrigerant leakage is reduced by reducing the amount of the refrigerant. It is possible to provide a refrigerator that can improve the safety of time.

[Brief description of drawings]

FIG. 1 is a cooling cycle diagram of a refrigerator according to an embodiment of the present invention.

FIG. 2 is a schematic sectional view of a flow path control means according to the same embodiment.

FIG. 3 is a characteristic diagram of the amount of refrigerant enclosed in the first evaporator according to the same embodiment.

FIG. 4 is a characteristic diagram of the amount of refrigerant enclosed in the second evaporator according to the same embodiment.

FIG. 5 is an operation time chart of the refrigerator according to the same embodiment.

FIG. 6 is a front view of first and second evaporators according to another embodiment of the present invention.

FIG. 7 is a cooling cycle diagram of a refrigerator according to another embodiment of the present invention.

FIG. 8 is an operation time chart of the refrigerator according to the same embodiment.

FIG. 9 is an operation time chart of a refrigerator according to another embodiment of the present invention.

FIG. 10 is an operation time chart of a refrigerator according to another embodiment of the present invention.

FIG. 11 is a cooling cycle diagram of a refrigerator according to another embodiment of the present invention.

FIG. 12 is an operation time chart of the refrigerator according to the same embodiment.

FIG. 13 is a cooling cycle diagram of a refrigerator according to another embodiment of the present invention.

FIG. 14 is an operation time chart of the refrigerator according to the same embodiment.

FIG. 15 is an operation time chart of a refrigerator according to another embodiment of the present invention.

FIG. 16 is an operation time chart of a refrigerator according to another embodiment of the present invention.

FIG. 17 is an operation time chart of a refrigerator according to another embodiment of the present invention.

FIG. 18 is a cooling cycle diagram of a refrigerator according to another embodiment of the present invention.

FIG. 19 is a cooling cycle diagram of a conventional refrigerator.

[Explanation of symbols]

1 compressor 2 condenser 3 first evaporator 4 Refrigerator 5 Second evaporator 6 freezer 7 First decompression means 8 Second decompression means 9 Check valve 10 First on-off valve 11 Second on-off valve 12 Flow path control means 13 First blower 14 Second blowing means 15 Refrigerator box 16 Machine room 17 First position 18 Second position 19 Third position 20 rotation axis 21 Seal member 22 cylinders 23 Defrost heater 24 Variable capacity compressor 25 Low pressure container type compressor

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-58-108376 (JP, A) JP-A-4-43262 (JP, A) JP-A-7-190582 (JP, A) JP-A-7- 120130 (JP, A) JP 58-88561 (JP, A) JP 9-113103 (JP, A) JP 11-148761 (JP, A) JP 10-148413 (JP, A) JP-A-11-237162 (JP, A) JP-A-11-248271 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) F25D 11/02

Claims (10)

(57) [Claims] 1. A low-pressure container type compressor, a condenser, a flow path control means, a first pressure reducing means, a first evaporator arranged in a refrigerating chamber, and a first air blowing means. A second refrigeration cycle including a second decompression means, a second evaporator provided in the freezing chamber, a second blowing means, and a check valve ;
A refrigerating chamber side cooling circuit is formed by the compressor, the condenser, the flow path control means, the first pressure reducing means, and the first evaporator. Together with the first pressure reducing means and the first evaporator, the second pressure reducing means, the second evaporator, and the check valve are connected in parallel to each other, and the compressor and the condenser are connected. Forming a refrigerating compartment side cooling circuit with the cooler, the flow path control means, the second decompression means, the second evaporator and the check valve, and the flow path control means of the refrigerant to each cooling circuit. independently of each other row Umono cooling of the freezing chamber and the refrigerating chamber by switching the flow, the pipe constituting the first evaporator
The capacity of the second evaporator and the capacity in the piping that constitutes the second evaporator
Compared with the amount of refrigerant required for the refrigerating compartment cooling circuit for cooling the freezing compartment, the amount of refrigerant required for the refrigerating compartment cooling circuit for cooling the refrigerating compartment is small by comparison. small comb and the refrigerant staying in the second evaporator
If a part of the
A refrigerator characterized in that an amount of refrigerant required to cool a room is ensured . 2. A freezer compartment cooling circuit to a refrigerator compartment cooling circuit
Just before switching to the
Operate the compressor with the outlet side of the condenser closed
The refrigerator according to claim 1, wherein the refrigerator is a refrigerator. 3. A defrost heater for periodically defrosting the second evaporator is provided, and immediately before the cooling of the freezing compartment is switched to the cooling of the refrigerating compartment, the condenser of the condenser is controlled by the flow path control means for a predetermined time. The refrigerator according to claim 2 , wherein the defrost heater is energized when the compressor is operated with the outlet side closed. 4. The defrost heater is used when the compressor is operated with the outlet side of the condenser closed by the flow path control means for a predetermined time immediately before switching from cooling of the freezer compartment to cooling of the refrigerating compartment. 3. The power is applied intermittently.
Refrigerator described in. 5. When the compressor is operated with the outlet side of the condenser closed by the flow path control means for a predetermined time immediately before the cooling of the freezer compartment is switched to the cooling of the refrigerating compartment, the second blower is provided. From the claim 2 , characterized in that it drives the means.
The refrigerator according to claim 4 . 6. The decompression amount by the first decompression means is 0.2M.
Claims characterized in that it is not less than Pa and not more than 0.5 MPa
The refrigerator according to any one of claims 2 to 5 . 7. The compressor has a variable capacity type, and the compressor is operated in a state in which the outlet side of the condenser is closed by the flow path control means for a predetermined time immediately before the cooling of the freezer compartment is switched to the cooling of the refrigerating compartment. 7. When the cooling of the refrigerating compartment is started after the operation, the compressor is operated at a rotational speed higher than a normal rotational speed for a predetermined time, and the compressor is operated according to any one of claims 2 to 6. Refrigerator. 8. The cooling of the refrigerating compartment is performed immediately after the cooling of the freezing compartment is switched to the cooling of the refrigerating compartment, after the compressor is operated for a predetermined time while the outlet side of the condenser is closed by the flow passage control means. The refrigerator according to any one of claims 2 to 7 , wherein when starting, the defrost heater is energized for a predetermined time. 9. Immediately before switching from cooling of the freezing compartment to cooling of the refrigerating compartment, the compressor is operated for a predetermined time while the outlet side of the condenser is closed by the flow path control means, and then the refrigerating compartment is cooled. when starting, claim claim 2, wherein the intermittently energized during defrosting heater for a predetermined time
The refrigerator according to 7 any one of. 10. The cooling of the refrigerating compartment is performed immediately after the cooling of the freezing compartment is switched to the cooling of the refrigerating compartment, after the compressor is operated for a predetermined time while the outlet side of the condenser is closed by the flow path control means. When starting, the 2nd ventilation means is operated for a predetermined time, The Claim 2 to Claim 9 characterized by the above-mentioned.
The refrigerator according to any one of 1.