JP2000230767A - Refrigerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To permit the improvement of reliability by a method wherein the amount of refrigerant for a cooling system for cooling a refrigerating chamber and a freezing chamber independently mutually is reduced and the efficiency of the cooling system is improved while the extreme low-pressure operation of a compressor is prevented. SOLUTION: In a refrigerator, a compressor 1 is operated (pump down) and a second fan 15 is operated immediately before switching from the cooling of a freezing chamber 6 into the cooling of a refrigerating chamber 4 and immediately before cooling the refrigerating chamber 4 upon starting the compressor 1 for a predetermined period of time under a condition that both of a first opening and closing valve 10 and a second opening and closing valve 11 are closed. According to this method, refrigerant, staying in a second evaporator 5, is purged into the side (high pressure side) of a condenser 2 and, thereafter, the first opening and closing valve 10 is opened to start the cooling of the refrigerating chamber 4.

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 and increase the efficiency thereof, and to improve the reliability by preventing extremely low pressure operation of the compressor. It is.

[0002]

2. Description of the Related Art FIG. 10 shows a schematic diagram 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 low-speed compressor, 2 is a condenser, 3 is a first evaporator disposed in a refrigerator 4, 5 is a freezer 6
A second evaporator disposed therein.

[0004] Reference numeral 7 denotes a first capillary arranged upstream of the refrigerant circuit of the first evaporator 3 for cooling the refrigerator compartment 4, and 8 denotes a second evaporator for cooling the freezer compartment 6. A second capillary 9 is provided on the upstream side of the refrigerant circuit of the vessel 5, and 9 is a check valve provided on the downstream side of the second evaporator 5 for cooling the freezing compartment.

[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. Inhaled.

[0008] The first evaporator 3 and the second evaporator 5 and the refrigerating compartment 4, which have become relatively low in temperature by evaporating and evaporating the refrigerant,
Each room is cooled by the heat exchange of the air in the freezing room 6.

[0009] The cooling operation of the refrigerator-freezer 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 refrigerator compartment 6 detects a temperature rise of a predetermined value or more, the compressor 1 is started and the refrigeration 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 freezing compartment 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. At this time, the evaporating temperature is set at -5 to 0 ° C. when the temperature of the refrigerating compartment 4 is about 5 ° C., and 2 to 2.5 times the normal evaporating temperature of −30 to −25 ° C. The operation of the compressor 1 is possible with the coefficient of performance.

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. At this time, the evaporating temperature of the refrigerating cycle is cooled at a normal evaporating temperature (-30 to -25 ° C) while the set temperature of the freezing compartment 6 is about -18 ° C.

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

Furthermore, 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 opening / closing 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 refrigerator 4 and the freezer compartment 6 are alternately arranged by distributing the refrigerant supply time to the first evaporator 3 and the second evaporator 5. Refrigeration cycle at the time of cooling the refrigerating compartment 4 is relatively high, so that a relatively high evaporation temperature (−5 to
C).

However, compared to the evaporation temperature (-5 to 0 ° C.) of the first evaporator 3 provided in the refrigerator compartment 4, the evaporation of the second evaporator 5 provided in the freezer compartment 6. Temperature (-30 to -25
° C) is considerably low, so that when switching from cooling the freezing compartment 6 to cooling the refrigerator compartment 4, the refrigerant staying in the low-temperature second evaporator 5 is unlikely to flow out, and sufficient refrigerant is supplied to the first evaporator 3. Since the refrigerant is not supplied, the amount of circulating refrigerant becomes insufficient, and the cooling effect of the refrigerator compartment 4 is reduced.

When the compressor 1 is stopped, the refrigerant stays in the second evaporator 5 because the second evaporator 5 disposed in the freezing chamber 6 has the lowest temperature in the refrigeration cycle. When cooling the refrigerator compartment 4 when the compressor 1 is started, the refrigerant retained in the low-temperature second evaporator 5 hardly flows out, and the first evaporator 3 is cooled.
Not enough refrigerant is supplied, the refrigerant circulation amount becomes insufficient, and the cooling effect of the refrigerator compartment 4 is reduced.

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.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problems, and makes it 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 an object of the present invention to provide a refrigerator capable of improving the reliability of a cooling system by preventing extreme low pressure operation of a compressor.

[0022]

In order to achieve this object, a refrigerator according to the present invention comprises a compressor having a low-pressure container type, a condenser, a first on-off valve, a first capillary, a refrigerator, and the like. A first evaporator, a first blower fan, a second on-off valve, a second capillary, a second evaporator arranged in the freezing chamber, and a second air blower A fan is provided, and the compressor, the condenser, the first capillary, and the first evaporator form a closed loop, and are arranged in parallel with the first capillary and the first evaporator. The second capillary, the second evaporator, and a check valve are connected to each other, and the flow of the refrigerant is switched by the first and second on-off valves, thereby cooling the refrigerator compartment and the freezer compartment to each other. It is performed independently, and switches from cooling the freezer compartment to cooling the refrigerator compartment. When the compressor is operated (pump-down) for a predetermined period of time before and immediately before the refrigerator is cooled when the compressor is started up and the first and second on-off valves are closed, A control means for operating the second blower fan is provided.

The state where both the first and second on-off valves are closed for a predetermined time immediately before switching from cooling of the freezing compartment to cooling of the refrigerator compartment, and immediately before cooling of the refrigerator compartment at the start of the compressor. When the compressor is operated by using the control means, a control means for operating the second blower fan at a high rotation speed is provided.

Further, immediately before switching from cooling of the freezing compartment to cooling of the refrigerator compartment, and immediately before cooling of the refrigerator compartment at the start of the compressor, the first and second on-off valves are both closed for a predetermined time. And a control means for operating the first blower fan when operating the compressor.

Further, a third blower fan for cooling the compressor and the condenser is provided, and immediately before switching from cooling of the freezing compartment to cooling of the refrigerating compartment, and immediately before cooling of the refrigerating compartment at the start of the compressor, the predetermined fan is provided. When the compressor is operated in a state where both the first and second on-off valves are closed for a period of time, control means for operating the third blower fan is provided.

An outside air temperature detecting means for detecting the outside air temperature is provided, and the compression is performed in a state where both the first and second on-off valves are closed for a predetermined time immediately before switching from cooling the freezing compartment to cooling the refrigerator compartment. When the air conditioner is operated, if the outside air temperature detected by the outside air temperature detecting means is high, a control means for operating the third blower fan at a high rotation speed is provided.

Further, when the compressor is operated with both the first and second on-off valves closed for a predetermined period of time immediately before switching from cooling of the freezing compartment to cooling of the refrigerator compartment, the outside air temperature detecting means is used. If the detected outside air temperature is low,
Control means for operating or stopping the third blower fan at low rotation is provided.

According to the present invention, the compressor is operated in a state where both the first and second on-off valves are closed, and the pump is forced down by moving the refrigerant from the low pressure side to the high pressure side. In addition, it is possible to expel the refrigerant remaining in the second evaporator to the condenser side (high pressure side). After pumping down, by opening the first on-off valve in the closed state of the second on-off valve, the refrigerant is supplied to the first evaporator quickly, so that the refrigerant circulation amount is not insufficient, and the efficiency is improved. By cooling the refrigerator compartment, an energy-saving refrigerator can be provided.

The above results show that the refrigerant can be used efficiently, so that the amount of the refrigerant can be reduced. In particular, when a flammable refrigerant (such as isoptan or propane) is used,
By reducing the amount of the refrigerant, it is possible to provide a refrigerator capable of improving safety at the time of refrigerant leakage.

Further, by controlling the first, second and third blower fans when the pump is down, the pump down can be promoted.
It is possible to provide a refrigerator capable of shortening the pump-down time (predetermined time) and improving the pump-down efficiency.

Further, by preventing extremely low pressure operation of the compressor when the pump is down, the load on the compressor can be reduced, and a refrigerator capable of improving the reliability of the cooling system can be provided.

[0032]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is arranged in a refrigerator having a low-pressure container type, a condenser, a first on-off valve, a first capillary, and a refrigerator. The first evaporator, the first blower fan, the second on-off valve, the second capillary, the second evaporator disposed in the freezing chamber, and the second blower fan Forming a closed loop with the compressor, the condenser, the first capillary, and the first evaporator, and forming the closed loop in parallel with the first capillary and the first evaporator. The second capillary, the second evaporator, and the check valve are connected to each other, and the cooling of the refrigerator compartment and the freezing compartment is independently performed by switching the flow of the refrigerant by the first and second on-off valves. Immediately before switching from cooling of the freezer compartment to cooling of the refrigerator compartment, and Immediately before the cooling of the refrigerating compartment at the time of startup, the first during the predetermined time, the operation of the compressor in a state that closes the second on-off valve (pump down)
And a control means for operating the second blower fan.

With the above configuration, the compressor is operated with both the first and second on-off valves closed and the pump is forced down to move the refrigerant from the low-pressure side to the high-pressure side. It is possible to expel the refrigerant remaining in the second evaporator to the condenser side (high pressure side). After pumping down, by opening the first on-off valve in the closed state of the second on-off valve, the refrigerant is supplied to the first evaporator quickly, so that the refrigerant circulation amount is not insufficient, and the efficiency is improved. It becomes possible to cool the refrigerator compartment.

In addition, the above results show that the refrigerant can be used efficiently, so that the amount of the refrigerant can be reduced. In particular, when a flammable refrigerant (such as isoptan or propane) is used,
By reducing the amount of the refrigerant, it becomes possible to enhance safety at the time of refrigerant leakage.

Further, when the pump down is started, the pressure (low pressure side pressure) of the refrigerant flowing into the compressor drops sharply, the refrigerant remaining in the second evaporator is evaporated and the evaporation temperature also drops rapidly. However, at this time, by operating the second blower fan to exchange heat between the second evaporator and the air in the freezing room, the evaporation temperature of the second evaporator is reduced and the low pressure side pressure is reduced. It is possible to suppress the decrease and promote the pump down.

Further, by suppressing the lowering of the low-pressure side pressure, an extremely low-pressure operation of the compressor can be prevented, the load on the compressor can be reduced, and the reliability of the cooling system can be improved.

By operating the second blower fan, pump down can be promoted, so that the pump down time (predetermined time) can be shortened, and the pump down efficiency can be improved. Become.

Further, since the air in the freezer compartment is cooled by heat exchange with the second evaporator whose evaporating temperature has temporarily decreased, the cooling efficiency of the freezer compartment can be improved.

In the above description, the example in which the first and second on-off valves are used as means for switching the flow of the refrigerant has been described. However, the flow paths to the first capillary and the second capillary are alternately opened and closed. The same effect can be obtained by using a three-way valve that can be closed simultaneously.

In this case, the same effect can be obtained by disposing the three-way valve on either the inlet side or the outlet side of the first capillary and the second capillary.

[0041] The invention according to claim 2 is characterized in that the first and the second cooling units are cooled for a predetermined time immediately before switching from cooling of the freezing room to cooling of the refrigerator room and immediately before cooling of the refrigerator room when the compressor is started.
When the compressor is operated in a state where both the second on-off valves are closed, a control means for operating the second blower fan at a high speed is provided.

By operating the second blower fan at a high speed during the pump down, the heat exchange between the second evaporator and the air in the freezing room is positively performed. , And the pressure on the low pressure side can be further suppressed, and the pump down can be further promoted.

Further, by suppressing the lowering of the low-pressure side pressure, it is possible to further prevent the compressor from operating at an extremely low pressure, reduce the load on the compressor, and improve the reliability of the cooling system. .

Further, by operating the second blower fan at a high rotation speed, the pump down can be further promoted, so that the pump down time (predetermined time) can be further reduced, and the pump down efficiency can be further improved. It can be improved.

Further, since the air in the freezing room is actively cooled by heat exchange with the second evaporator whose evaporating temperature has temporarily dropped, the cooling efficiency of the freezing room can be further improved. Become.

The invention according to claim 3 is characterized in that the first and second cooling units are cooled for a predetermined time immediately before switching from cooling of the freezing room to cooling of the refrigerator room and immediately before cooling of the refrigerator room when the compressor is started.
When the compressor is operated with both the second on-off valves closed, control means for operating the first blower fan is provided.

When pump down is started, the pressure (low pressure side) of the refrigerant flowing into the compressor drops rapidly, and a small amount of the refrigerant remaining in the first evaporator is evaporated and vaporized, and the evaporation temperature also decreases. At that time, by operating the first blower fan, the air in the refrigerator compartment is cooled by heat exchange with the first evaporator whose evaporation temperature has temporarily decreased, so that the cooling efficiency of the refrigerator compartment is reduced. Can be further improved.

According to a fourth aspect of the present invention, a third blower fan for cooling the compressor and the condenser is provided, and the third fan is provided immediately before switching from cooling of the freezing room to cooling of the refrigerator room, and at the time of starting the compressor. Immediately before performing cooling, the first for a predetermined time,
When the compressor is operated with both the second on-off valves closed, control means for operating the third blower fan is provided.

When the pump down is started, the pressure of the refrigerant flowing into the compressor (low pressure side pressure) drops sharply, and the pressure of the refrigerant discharged from the compressor (high pressure side pressure) rises.
At this time, by operating the third blower fan, it is possible to suppress a rise in the temperature of the compressor and the condenser and a rise in the high-pressure side pressure, and to promote the pump down.

Further, by operating the third blower fan, the pump down can be promoted, so that the pump down time (predetermined time) can be shortened and the pump down efficiency can be improved. Become.

According to a fifth aspect of the present invention, an outside air temperature detecting means for detecting an outside air temperature is provided, and the first and second on-off valves are provided for a predetermined time immediately before switching from cooling of the freezing room to cooling of the refrigerator room. When operating the compressor with both closed,
When the outside air temperature detected by the outside air temperature detecting means is high, a control means for operating the third blowing fan at a high rotation speed is provided.

When the pump down is started, the pressure of the refrigerant flowing into the compressor (low pressure side pressure) drops sharply, and the pressure of the refrigerant discharged from the compressor (high pressure side pressure) rises.
In particular, when the outside air temperature is high, the pressure on the high pressure side increases, so that the efficiency of pump down decreases. Therefore, when the outside air temperature detected by the outside air temperature detecting means is higher than normal, by operating the third fan at a high rotation, the temperature rise of the compressor and the condenser and the rise of the high pressure side pressure are suppressed, It is possible to prevent a decrease in pump down efficiency at a high outside air temperature.

According to a sixth aspect of the present invention, the compressor is operated with both the first and second on-off valves closed for a predetermined period of time immediately before switching from cooling the freezing compartment to cooling the refrigerator compartment. When the outside air temperature detected by the outside air temperature detecting means is low, a control means for operating or stopping the third blower fan at a low speed is provided.

When the pump down is started, the pressure of the refrigerant flowing into the compressor (low pressure side pressure) drops sharply, and the pressure of the refrigerant discharged from the compressor (high pressure side pressure) rises.
In particular, when the outside air temperature is low, the low-pressure side pressure is low, so that the compressor may be operated at an extremely low pressure. Therefore, when the outside air temperature detected by the outside air temperature detecting means is lower than usual, the third fan is operated at a low rotation or stopped to reduce the temperature of the compressor and the condenser and to reduce the high-pressure side pressure. By suppressing the decrease and the decrease of the low pressure side pressure, it is possible to prevent the compressor from operating at extremely low pressure at low outside air temperature, reduce the load on the compressor and improve the reliability of the cooling system Becomes

Hereinafter, embodiments of the present invention will be described with reference to FIGS.
This will be described with reference to FIG. 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 schematic diagram of a refrigerator cooling system according to one embodiment of the present invention, and FIG. 2 is a time chart of the embodiment.

A compressor 1 of a low pressure vessel type and a condenser 2
A first on-off valve 10, a first capillary 7, a first evaporator 3 disposed in the refrigerator compartment 4, a first blower fan 14, a second on-off valve 11, Second capillary 8
, A second evaporator 5 disposed in the freezing compartment 6, and a second blower fan 15, and the compressor 1, the condenser 2, the first capillary 7, the first evaporator 3, And a second capillary 8, a second evaporator 5, and a check valve 9 are connected so as to be in parallel with the first capillary 7 and the first evaporator 3.

The first on-off valve 10 and the second on-off valve 11 are provided on the upstream side (outlet side) of the first capillary 7 and the second capillary 8, respectively, and the check valve 9 is provided on the second evaporator. 5 is provided on the downstream side.

Numeral 12 denotes a refrigerator box, in which a refrigerator compartment 4 which is a relatively high temperature compartment is arranged in an upper part, and a freezer compartment 6 which is a relatively low temperature compartment is arranged in a lower part. It is configured to insulate the surroundings with heat insulating material. Storage of foods and the like is carried out through an insulated door (not shown).

The compressor 1, the condenser 2, the first on-off valve 10 and the second on-off valve 11 reduce the number of pipe connection points in the refrigerator box 12 from the viewpoint of improving safety when a flammable refrigerant is used. Is disposed in the machine room 15.

The refrigerating compartment 4 and the freezing compartment 6 are provided with temperature detecting means (not shown) for detecting the temperature in the compartment, respectively. The compressor 1, the first on-off valve 10, the second on-off valve 11, and the first A control unit (not shown) for controlling the blower fan 14 and the second blower fan 15 is provided.

With respect to 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 freezing compartment 6 is being cooled, the first on-off valve 10 is closed and the second on-off valve 11 is open. Further, the first blower fan 14 is stopped, and the second blower fan 15 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, decompressed by the second capillary 8 via the second on-off valve 11, and then to the second evaporator 5. The refrigerant in the second evaporator 5 evaporates by flowing in and exchanging heat with the air in the refrigerator compartment 6 by the operation of the second blower fan 15, and the heat-exchanged air has a lower temperature. It becomes air and cools the freezing room 6.

When the temperature detecting means of the refrigerator compartment 4 detects that the temperature exceeds the predetermined temperature while the freezing compartment 6 is being cooled, the second on-off valve 11 is closed (T1).

At this time, the compressor 1 is operating (pump down) and the second blower fan 15 is operating with both the first on-off valve 10 and the second on-off valve 11 closed. State.

After the pump down is performed for a predetermined time (Ta), the first on-off valve 1 is closed with the second on-off valve 11 closed.
0 is released, the first blower fan 14 is operated, and the second blower fan 15 is stopped (T2).

The refrigerant is depressurized by the first capillary 7 through the compressor 1, the condenser 2, and the first on-off valve 10, then flows into the first evaporator 3, and the first blower fan 14 By performing the heat exchange with the air in the refrigerator compartment 4 by the operation, the refrigerant in the first evaporator 3 evaporates and evaporates, and the heat-exchanged air becomes lower-temperature air to cool the refrigerator compartment 4. .

When the temperature detecting means of the freezer compartment 6 detects that the temperature exceeds a predetermined temperature while the refrigerator compartment 4 is being cooled, the first on-off valve 10 is closed and the second on-off valve 11 is closed.
Is released, the first blower fan 14 is stopped, and the second blower fan 15 is operated (T3).

The refrigerant is decompressed by the second capillary 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 blower fan 15 By performing the heat exchange with the air in the refrigerator compartment 6, the refrigerant in the second evaporator 5 evaporates, and the heat-exchanged air becomes lower-temperature air to cool the freezer compartment 6. .

The above operation is repeated, and the first on-off valve 10
The refrigerating compartment 4 and the freezing compartment 6 are alternately cooled by switching the flow of the refrigerant with the second on-off valve 11 and the temperature detecting means of the refrigerating compartment 4 and the freezing compartment 6 are lower than a predetermined temperature. Is detected, the first open / close valve 10 and the second open / close valve 11 are both opened, the first blower fan 14 and the second blower fan 15 are stopped, and the compressor 1 is stopped (T
4).

While the compressor 1 is stopped, the refrigerant stays in the second evaporator 5 because the second evaporator 5 disposed in the freezing chamber 6 has the lowest temperature in the refrigeration cycle.

When the temperature in the refrigerator compartment 4 rises while the compressor 1 is stopped, the temperature detecting means of the refrigerator compartment 4 detects that the temperature exceeds a predetermined temperature. When the control means receives this signal, the first opening / closing valve 10 and the second opening / closing valve 11 are closed for a predetermined time (Ta), the compressor 1 is operated (pump down), and the second ventilation is performed. The operation of the fan 15 is performed (T5).

After the pump down, the first on-off valve 10 is opened with the second on-off valve 11 closed, the first blower fan 14 is operated, the second blower fan 15 is stopped, and the refrigerator is refrigerated. The cooling of the chamber 4 is performed (T6).

Further, while the compressor 1 is stopped, the temperature in the freezing compartment 6 rises sharply, and before the temperature detecting means in the refrigerator compartment 4 reaches a predetermined temperature, the temperature detecting means in the freezing compartment 6 is increased. If the control means detects that the temperature exceeds a predetermined temperature, the control means receives this signal, opens the second on-off valve 11, closes the first on-off valve 10, and connects the compressor 1 with the second on-off valve. Is operated to cool the freezing compartment 6.

As described above, immediately before switching from the cooling of the freezing compartment 6 to the cooling of the refrigerator compartment 4 and immediately before the cooling of the refrigerator compartment 4 when the compressor 1 is started, the first on-off valve 10 and the second The compressor 1 is operated in a state in which both the on-off valves 11 are closed, and the refrigerant is forced to move from the low-pressure side to the high-pressure side, thereby performing a pump-down operation. To the condenser 2 side (high pressure side). After the pump is down, the first on-off valve 10 is opened while the second on-off valve 11 is closed,
Since the refrigerant of the first evaporator 3 is quickly supplied, the amount of circulating refrigerant does not become insufficient, and the refrigerator compartment 4 can be efficiently cooled.

Further, since the refrigerant can be used efficiently from the above results, the amount of the refrigerant can be reduced. Particularly when a flammable refrigerant (such as isoptan or propane) is used,
By reducing the amount of the refrigerant, it becomes possible to enhance safety at the time of refrigerant leakage.

Further, when the pump-down is started, the pressure of the refrigerant flowing into the compressor 1 (low pressure side pressure) drops sharply, the refrigerant remaining in the second evaporator 5 is evaporated and evaporated, and the evaporation temperature also rises rapidly. At this time, by operating the second blower fan 15, heat exchange between the second evaporator 5 and the air in the freezing room 6 is performed, so that the evaporation temperature of the second evaporator 5 is reduced. , And the pressure on the low pressure side can be suppressed, and pump down can be promoted.

Further, by suppressing the lowering of the low pressure side pressure, an extremely low pressure operation of the compressor 1 can be prevented.
The load on the compressor 1 can be reduced, and the reliability of the cooling system can be improved.

By operating the second blower fan 15, pump down can be promoted.
The pump down time (predetermined time (Ta)) can be reduced, and the pump down efficiency can be improved.

Further, since the air in the freezing room 6 is cooled by heat exchange with the second evaporator 5 whose evaporation temperature has been temporarily lowered, the cooling efficiency of the freezing room 6 can be improved. Become.

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

The detailed description of the same components as in the first embodiment is omitted, and the same reference numerals are given.

During the cooling of the freezing compartment 6, the first on-off valve 10 is closed and the second on-off valve 11 is open. Further, the first blower fan 14 is stopped, and the second blower fan 15 is operating at a normal rotation speed.

When the temperature detecting means of the refrigerating compartment 4 detects that the temperature exceeds a predetermined temperature while the freezing compartment 6 is being cooled, the second on-off valve 11 is closed and the second blower fan 15 is closed. Is operated at a higher speed than usual (T1).

At this time, the compressor 1 is operating (pump down) while both the first on-off valve 10 and the second on-off valve 11 are closed, and the second blower fan 15 is operated at a high speed. It is in the state of doing.

After the pump down has been performed for a predetermined time (Ta), the first on-off valve 1 is closed with the second on-off valve 11 closed.
0, the first fan 14 is operated, the second fan 15 is stopped, and the refrigerator 4 is cooled (T
2).

When the temperature detecting means of the freezing compartment 6 detects that the temperature exceeds a predetermined temperature while the refrigerator compartment 4 is being cooled, the first opening / closing valve 10 is closed and the second opening / closing valve 11 is closed.
Is released, the first blower fan 14 is stopped, and the second blower fan 15 is operated at a normal rotation speed to cool the freezing compartment 6 (T3).

The above operation is repeated, and the first on-off valve 10
The refrigerating compartment 4 and the freezing compartment 6 are alternately cooled by switching the flow of the refrigerant with the second on-off valve 11 and the temperature detecting means of the refrigerating compartment 4 and the freezing compartment 6 are lower than a predetermined temperature. Is detected, the first open / close valve 10 and the second open / close valve 11 are both opened, the first blower fan 14 and the second blower fan 15 are stopped, and the compressor 1 is stopped (T
4).

When the temperature in the refrigerator compartment 4 increases while the compressor 1 is stopped, the temperature detecting means of the refrigerator compartment 4 detects that the temperature exceeds a predetermined temperature. When the control means receives this signal, the first opening / closing valve 10 and the second opening / closing valve 11 are closed for a predetermined time (Ta), the compressor 1 is operated (pump down), and the second ventilation is performed. The operation is performed at a high speed of the fan 15 (T5).

After pump down, the first on-off valve 10 is opened with the second on-off valve 11 closed, the first blower fan 14 is operated, the second blower fan 15 is stopped, and refrigeration is performed. The cooling of the chamber 4 is performed (T6).

By operating the second blower fan 15 at a high speed during the pump down, the second evaporator 5 and the air in the freezer 6 are actively exchanged with each other, so that the second evaporation It is possible to further suppress a decrease in the evaporating temperature of the vessel 5 and a decrease in the low-pressure side pressure, and to further promote the pump down.

Further, by further suppressing the lowering of the low pressure side pressure, extremely low pressure operation of the compressor 1 can be further prevented, the load on the compressor 1 can be reduced, and the reliability of the cooling system can be improved. Becomes

Also, by operating the second blower fan at a high rotation speed, the pump down can be further promoted, so that the pump down time (predetermined time (Ta)) can be further reduced, and the pump down time can be reduced. Efficiency can be further improved.

Further, since the air in the freezing chamber 6 is actively cooled by heat exchange with the second evaporator 5 whose evaporation temperature has temporarily decreased, the cooling effect of the freezing chamber 6 can be further improved. Becomes possible.

(Embodiment 3) FIG. 4 is a time chart of an embodiment 3 of the present invention.

The same components as those of the first embodiment are not described in detail, and are denoted by the same reference numerals.

While the freezing compartment 6 is being cooled, the first on-off valve 10 is closed and the second on-off valve 11 is open. Further, the first blower fan 14 is stopped, and the second blower fan 15 is operating.

When the temperature detecting means of the refrigerating compartment 4 detects that the temperature exceeds a predetermined temperature while the freezing compartment 6 is being cooled, the second opening / closing valve 11 is closed and the second blowing fan 14 Is driven (T1).

At this time, the compressor 1 is operating (pump down) with both the first on-off valve 10 and the second on-off valve 11 closed, and the first blower fan 14 and the second blower The fan 15 is operating.

After the pump-down has been performed for a predetermined time (Ta), the first on-off valve 1 is closed with the second on-off valve 11 closed.
0, the second blower fan 15 is stopped, and the refrigerator compartment 4
Is cooled (T2).

When the temperature detecting means of the freezing compartment 6 detects that the temperature exceeds a predetermined temperature while the refrigerator compartment 4 is being cooled, the first opening / closing valve 10 is closed and the second opening / closing valve 11 is closed.
Is released, the first blower fan 14 is stopped, and the second blower fan 15 is operated (T3).

By repeating the above operation, the first on-off valve 10
The refrigerating compartment 4 and the freezing compartment 6 are alternately cooled by switching the flow of the refrigerant with the second on-off valve 11 and the temperature detecting means of the refrigerating compartment 4 and the freezing compartment 6 are lower than a predetermined temperature. Is detected, the first open / close valve 10 and the second open / close valve 11 are both opened, the first blower fan 14 and the second blower fan 15 are stopped, and the compressor 1 is stopped (T
4).

When the temperature in the refrigerator compartment 4 rises while the compressor 1 is stopped, the temperature detecting means of the refrigerator compartment 4 detects that the temperature exceeds a predetermined temperature. When the control means receives this signal, the first opening / closing valve 10 and the second opening / closing valve 11 are closed for a predetermined time (Ta), the compressor 1 is operated (pump down), and the first ventilation is performed. The operation of the fan 14 and the second blower fan 15 is performed (T5).

After the pump down, the first on-off valve 10 is opened with the second on-off valve 11 closed, the second blower fan 15 is stopped, and the refrigerator compartment 4 is cooled (T6).

When pump down is started, the pressure (low pressure side) of the refrigerant flowing into the compressor 1 drops sharply, and a small amount of the refrigerant remaining in the first evaporator 3 evaporates and the evaporation temperature also drops. However, at this time, by operating the first blower fan 3, the air in the refrigerator compartment 4 is cooled by heat exchange with the first evaporator 3 whose evaporation temperature has temporarily decreased, The cooling efficiency of the refrigerator compartment 4 can be further improved.

Fourth Embodiment FIG. 5 is a schematic diagram of a refrigerator cooling system according to a fourth embodiment of the present invention, and FIG. 6 is a time chart of the fourth embodiment.

The detailed description of the same components as those in the first embodiment is omitted, and the same reference numerals are given.

A compressor 16 is disposed in the machine room 13 and
And a third blower fan for cooling the condenser 12.

During the cooling of the freezing compartment 6, the first on-off valve 10 is closed and the second on-off valve 11 is open. Further, the first blower fan 14 is stopped, and the second blower fan 15 and the third blower fan 16 are operating.

When the temperature detecting means of the refrigerating compartment 4 detects that the temperature exceeds a predetermined temperature while the freezing compartment 6 is being cooled, the second on-off valve 11 is closed (T1).

At this time, the compressor 1 is operating (pump down) while the first on-off valve 10 and the second on-off valve 11 are both closed, and the second blower fan 15 and the third blower The fan 16 is operating.

After the pump has been down for a predetermined time (Ta), the first on-off valve 1 is closed with the second on-off valve 11 closed.
0, the first fan 14 is operated, the second fan 15 is stopped, and the refrigerator 4 is cooled (T
2).

When the temperature detecting means of the freezer compartment 6 detects that the temperature exceeds a predetermined temperature while the refrigerator compartment 4 is being cooled, the first on-off valve 10 is closed and the second on-off valve 11 is closed.
Is released, the first blower fan 14 is stopped, and the second blower fan 15 is operated (T3).

The above operation is repeated, and the first on-off valve 10
The refrigerating compartment 4 and the freezing compartment 6 are alternately cooled by switching the flow of the refrigerant with the second on-off valve 11 and the temperature detecting means of the refrigerating compartment 4 and the freezing compartment 6 are lower than a predetermined temperature. Is detected, the first open / close valve 10 and the second open / close valve 11 are both opened, the first blower fan 14, the second blower fan 15, and the third blower fan 16 are stopped, and the compressor 1
Is stopped (T4).

When the temperature in the refrigerator compartment 4 rises while the compressor 1 is stopped, the temperature detecting means of the refrigerator compartment 4 detects that the temperature exceeds a predetermined temperature. When the control means receives this signal, the first opening / closing valve 10 and the second opening / closing valve 11 are closed for a predetermined time (Ta), the compressor 1 is operated (pump down), and the second ventilation is performed. The operation of the fan 15 and the third blower fan 16 is performed (T5).

After the pump down, the first on-off valve 10 is opened with the second on-off valve 11 closed, the first blower fan 14 is operated, the second blower fan 15 is stopped, and the refrigerator is refrigerated. The cooling of the chamber 4 is performed (T6).

Further, while the compressor 1 is stopped, the temperature in the freezing compartment 6 rises sharply, and before the temperature detecting means in the refrigerator compartment 4 reaches a predetermined temperature, the temperature detecting means in the freezing compartment 6 is increased. If the control means detects that the temperature exceeds a predetermined temperature, the control means receives this signal, opens the second on-off valve 11, closes the first on-off valve 10, and connects the compressor 1 with the second on-off valve. Operation of the blower fan 15 and the third blower fan 16,
The freezing room 6 is cooled.

When the pump down is started, the pressure of the refrigerant flowing into the compressor 1 (low pressure side) drops sharply, and the pressure of the refrigerant discharged from the compressor 1 (high pressure side pressure) rises. By operating the third blower fan 16,
It is possible to suppress a rise in the temperature of the compressor 1 and the condenser 2 and a rise in the high-pressure side pressure, and to promote pump-down.

By operating the third blower fan 16, pump down can be promoted.
The pump down time (predetermined time (Ta)) can be reduced, and the pump down efficiency can be improved.

(Embodiment 5) FIG. 7 is a schematic diagram of a refrigerator cooling system according to a fifth embodiment of the present invention, and FIG. 8 is a time chart of the embodiment.

The same components as those in the first embodiment are not described in detail, and are denoted by the same reference numerals.

17 is installed outside the refrigerator box 12,
It is an outside air temperature detecting means for detecting the outside air temperature.

During the cooling of the freezing compartment 6, the first on-off valve 10 is closed and the second on-off valve 11 is open. Further, the first blower fan 14 is stopped, and the second blower fan 15 and the third blower fan 16 are operating at a normal rotation speed.

When the temperature detecting means of the refrigerating compartment 4 detects that the temperature exceeds a predetermined temperature while cooling the freezing compartment 6, the second on-off valve 11 is closed (T1).

At this time, the compressor 1 is operating (pump down) while the first on-off valve 10 and the second on-off valve 11 are both closed, and the second blower fan 15 and the third blower The fan 16 is operating.

When the outside air temperature detected by the outside air temperature detecting means 17 is higher than usual at the time of pump down, the third blower fan 16 is set by the control means to operate at a high speed.

After the pump down set as described above is performed for a predetermined time (Ta), the first on-off valve 10 is opened with the second on-off valve 11 closed, and the first blower fan 14 is opened. Is operated, the second blower fan 15 is stopped, and the refrigerator compartment 4 is cooled (T2).

When the pump down is started, the pressure of the refrigerant flowing into the compressor 1 (low pressure side pressure) drops sharply, and the pressure of the refrigerant discharged from the compressor 1 (high pressure side pressure) rises. When the outside air temperature is high, the high-pressure side pressure increases, so that the efficiency of pump down decreases. Therefore, when the outside air temperature detected by the outside air temperature detecting means 17 is higher than usual, the third fan 16 is operated at a high speed to increase the temperature of the compressor 1 and the condenser 2 and increase the high-pressure side pressure. It is possible to suppress the rise and prevent a decrease in pump down efficiency at a high outside temperature.

(Embodiment 6) FIG. 9 is a time chart of an embodiment 6 of the present invention.

The detailed description of the same components as those in the first embodiment is omitted, and the same reference numerals are given.

While the freezing compartment 6 is being cooled, the first on-off valve 10 is closed and the second on-off valve 11 is open. Further, the first blower fan 14 is stopped, and the second blower fan 15 and the third blower fan 16 are operating at a normal rotation speed.

When the temperature detecting means of the refrigerator compartment 4 detects that the temperature exceeds the predetermined temperature while the freezing compartment 6 is being cooled, the second on-off valve 11 is closed (T1).

At this time, the compressor 1 is operating (pump down) while the first on-off valve 10 and the second on-off valve 11 are both closed, and the second blower fan 15 and the third blower The fan 16 is operating.

When the outside air temperature detected by the outside air temperature detecting means 17 is lower than normal at the time of pump down, the third blower fan 16 is set by the control means to operate at a low speed or to stop. .

After the pump down set as described above is performed for a predetermined time (Ta), the first on-off valve 10 is opened with the second on-off valve 11 closed, and the first blower fan 14 is opened. Is operated, the second blower fan 15 is stopped, and the refrigerator compartment 4 is cooled (T2).

When the pump down is started, the pressure of the refrigerant flowing into the compressor 1 (low pressure side pressure) drops sharply, and the pressure of the refrigerant discharged from the compressor 1 (high pressure side pressure) rises. When the outside air temperature is high, the low-pressure side pressure is low, so that the compressor 1 may be operated at an extremely low pressure. Therefore, when the outside air temperature detected by the outside air temperature detecting means 17 is lower than usual, the third fan 16 is operated at a low rotation or stopped to reduce the temperature of the compressor 1 and the condenser 2 and reduce the temperature. By suppressing the decrease in the high-pressure side pressure and the decrease in the low-pressure side pressure, it is possible to prevent an extremely low pressure operation of the compressor 1 at the time of a low outside air temperature, reduce the load on the compressor 1, and reduce the cooling system. Reliability can be improved.

[0137]

According to the present invention, the compressor is operated with both the first and second on-off valves closed, and the pump is forced down to move the refrigerant from the low pressure side to the high pressure side. This makes it possible to expel the refrigerant remaining in the second evaporator to the condenser side (high-pressure side). After pumping down, by opening the first on-off valve in the closed state of the second on-off valve, the refrigerant is supplied to the first evaporator quickly, so that the refrigerant circulation amount is not insufficient, and the efficiency is improved. By cooling the refrigerator compartment, an energy-saving refrigerator can be provided.

Further, since the refrigerant can be used efficiently from the above results, the amount of the refrigerant can be reduced. In particular, when a flammable refrigerant (such as isoptan or propane) is used,
By reducing the amount of the refrigerant, it is possible to provide a refrigerator capable of improving safety at the time of refrigerant leakage.

Further, at the time of pump down, the pump down can be promoted by controlling the first blower fan, the second blower fan, and the third blower fan.
It is possible to provide a refrigerator capable of shortening the pump-down time (predetermined time) and improving the pump-down efficiency.

Further, by preventing the compressor from operating at an extremely low pressure when the pump is down, a load on the compressor can be reduced, and a refrigerator capable of improving the reliability of the cooling system can be provided.

[Brief description of the drawings]

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

FIG. 2 is a time chart showing a first embodiment of the present invention.

FIG. 3 is a time chart showing a second embodiment of the present invention;

FIG. 4 is a time chart showing a third embodiment of the present invention.

FIG. 5 is a schematic diagram of a refrigerator cooling system according to a fourth embodiment of the present invention.

FIG. 6 is a time chart showing a fourth embodiment of the present invention.

FIG. 7 is a schematic diagram of a refrigerator cooling system according to a fifth embodiment of the present invention.

FIG. 8 is a time chart showing a fifth embodiment of the present invention.

FIG. 9 is a time chart showing a sixth embodiment of the present invention.

FIG. 10 is a schematic diagram of a conventional refrigerator cooling system.

[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 9 Check valve 10 First on-off valve 11 Second on-off valve 12 refrigerator box 13 machine room 14 first blower fan 15 second blower fan 16 third blower fan 17 outside air temperature detecting means

Continuation of the front page (72) Inventor Tetsuya Saito 4-5-2-5 Takaida Hondori, Higashiosaka-shi, Osaka Matsushita Refrigerator Co., Ltd. F term (reference) 3L045 AA02 AA03 BA01 CA02 DA02 EA01 HA02 HA07 JA14 JA16 LA05 LA09 LA10 MA04 MA05 MA12 NA03 PA01 PA05

Claims (6)

[Claims] 1. A low-pressure container type compressor, a condenser, a first on-off valve, a first capillary, a first evaporator disposed in a refrigerator, and a first blower fan A second on-off valve, a second capillary, a second evaporator disposed in the freezing chamber, and a second blower fan, the compressor, the condenser, and the first Forming a closed loop between the capillary and the first evaporator, and the second capillary, the second evaporator, and the check valve so as to be in parallel with the first capillary and the first evaporator; And by switching the flow of the refrigerant by the first and second on-off valves, the cooling of the refrigerating room and the freezing room is performed independently of each other. From the cooling of the freezing room to the refrigerating room, Immediately before switching to cooling, and immediately before cooling the refrigerator compartment when starting the compressor. The first during the predetermined time, the refrigerator operate the compressor in a state that closes the second on-off valve to (pump down), characterized by comprising control means for operating the second blow fan. 2. A state in which both the first and second on-off valves are closed for a predetermined time immediately before switching from cooling of the freezing compartment to cooling of the refrigerator compartment, and immediately before cooling of the refrigerator compartment when starting the compressor. 2. The refrigerator according to claim 1, further comprising control means for operating the second blower fan at a high rotation speed when the compressor is operated in the refrigerator. 3. A state in which both the first and second on-off valves are closed for a predetermined time immediately before switching from cooling of the freezing compartment to cooling of the refrigerator compartment, and immediately before cooling of the refrigerator compartment when starting the compressor. The refrigerator according to claim 1 or 2, further comprising control means for operating the first blower fan when operating the compressor in (1). 4. A third blower fan for cooling the compressor and the condenser is provided, which is provided immediately before switching from cooling of the freezing compartment to cooling of the refrigerator compartment, and immediately before cooling of the refrigerator compartment when the compressor is started. When operating the compressor in a state where both the first and second on-off valves are closed for a period of time, control means for operating the third blower fan is provided.
3. The refrigerator according to any one of the three items. 5. An outside air temperature detecting means for detecting an outside air temperature, wherein the compression is performed in a state where both the first and second on-off valves are closed for a predetermined time immediately before switching from cooling of the freezing compartment to cooling of the refrigerator compartment. And a control means for operating the third blower fan at a high speed when the outside air temperature detected by the outside air temperature detection means is high when the machine is operated. Item. 6. When the compressor is operated with both the first and second on-off valves closed for a predetermined time immediately before switching from cooling of the freezing compartment to cooling of the refrigerator compartment, the outside air temperature detecting means detects the temperature. The refrigerator according to any one of claims 1 to 5, further comprising control means for operating or stopping the third blower fan at a low rotation when the outside air temperature is low.