JP2000266444A - Refrigerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a cooling system for cooling a refrigeration compartment and a freezing compartment independently in which the quantity of refrigerant is reduced while enhancing the efficiency and the reliability is enhanced by preventing extremely low pressure operation of a compressor. SOLUTION: Immediately before switching the cooling operation from a freezing compartment 6 to a refrigeration compartment 4 and immediately before the refrigeration compartment 4 is cooled after starting a compressor 1, the compressor 1 is operated (pump down) for a predetermined time while closing both first and second on/off valves 10, 11 to purge a refrigerant standing in a second evaporator 5 to the condenser 2 side (high pressure side). Subsequently, the first on/off valve 10 is opened and cooling operation of the refrigeration compartment 4 is started.

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. 19 is a schematic view of a refrigerator disclosed in Japanese Patent Publication No. 62-22396 as an example of a conventional cooling cycle and a refrigerator.

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

[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 ° C to 0 ° C when the temperature of the refrigerating compartment 4 is set at about 5 ° C, and 2 to 2.5 ° C for the normal evaporating temperature of -30 to -25 ° C. The compressor 1 can be operated with a double 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 on-off valve 10 is provided downstream of the first evaporator 3 and is closed, so that the refrigerant can be stored in the first evaporator 3 and the amount of the refrigerant can be adjusted.

[0017]

In the above-mentioned conventional refrigerator, the refrigerating compartment 4 and the freezing compartment 6 are divided in the supply time of the refrigerant to the first evaporator 3 and the second evaporator 5, and By alternately cooling repeatedly, the refrigeration cycle at the time of cooling the refrigerator compartment 4 is set to a relatively high evaporation temperature (−5 to 0) having a good coefficient of performance of the compressor 1.
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. The refrigerant is not supplied, and the circulation amount of the refrigerant becomes insufficient, and the cooling efficiency 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.
Is not supplied, and the amount of circulating refrigerant is insufficient, and the cooling efficiency 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 extremely low pressure operation of a compressor.

[0022]

According to the present invention, there is provided a refrigerator comprising a compressor, a condenser, a first on-off valve, a first capillary, and a refrigerator. A first evaporator, a second on-off valve, a second capillary, and a second evaporator disposed in a freezing chamber, the compressor, the condenser, and the first capillary. While forming a closed loop with the first evaporator, the second capillary, the second evaporator, and a check valve so as to be in parallel with the first capillary and the first evaporator. Connected to each other to perform cooling of the refrigerator and the freezer independently of each other by switching the flow of the refrigerant by the first and second on-off valves. Immediately before switching to cooling, and when starting the compressor, the refrigerator compartment is cooled. In, characterized by comprising control means for operating (pump down) of the compressor in a state wherein the first, which together close the second on-off valve for a predetermined time.

Further, the apparatus is provided with an evaporating temperature detecting means for detecting the evaporating temperature of the second evaporator, and immediately before switching from cooling of the freezing room to cooling of the refrigerating room, and immediately before cooling of the refrigerating room when the compressor is started. And control means for operating the compressor with both the first and second on-off valves closed until the evaporation temperature of the second evaporator detected by the evaporation temperature detection means reaches a predetermined temperature. It is characterized by the following.

Immediately before switching from cooling of the freezing compartment to cooling of the refrigerating compartment, the first and the second evaporators for a predetermined period of time set by the evaporation temperature of the second evaporator immediately before the switch is detected by the evaporating temperature detecting means. Control means for operating the compressor in a state in which both the second on-off valves are closed is provided.

Further, the compressor is a variable capacity type compressor, and immediately before switching from cooling of the freezing room to cooling of the refrigerator compartment, the evaporating temperature of the second evaporator immediately before the switching is detected by the evaporating temperature detecting means. Control means for operating the compressor for a predetermined time at a separately set operation frequency is provided.

Further, immediately before switching from cooling of the freezing compartment to cooling of the refrigerating compartment, at a predetermined time and an operating frequency set for each evaporation temperature of the second evaporator immediately before the switching detected by the evaporation temperature detecting means. Control means for operating the compressor with both the first and second on-off valves closed is provided.

Further, low pressure detecting means for detecting the pressure of the refrigerant flowing into the compressor 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 at the start of the compressor. And a control unit for operating the compressor with both the first and second on-off valves closed until the pressure detected by the low-pressure detection unit reaches a predetermined pressure.

Further, immediately before switching from cooling of the freezing compartment to cooling of the refrigerator compartment, both the first and second opening / closing valves are set together for a predetermined time set for each pressure immediately before the switching detected by the low pressure detecting means. Control means for operating the compressor in a closed state is provided.

Further, the compressor is a variable capacity compressor, and immediately before switching from cooling of the freezing room to cooling of the refrigerating room, a certain operating frequency set for each pressure immediately before the switching detected by the low pressure detection means. And a control means for operating the compressor for a predetermined time.

Further, immediately before switching from cooling of the freezing compartment to cooling of the refrigerating compartment, the first and second opening / closing valves are operated for a predetermined time and operating frequency set for each pressure immediately before the switching detected by the low pressure detecting means. And a control means for operating the compressor in a state where both are closed.

Further, an outside air temperature detecting means for detecting the outside air temperature is provided. Immediately before switching from the cooling of the freezing room to the cooling of the refrigerating room, a predetermined time set by the outside air temperature detected by the outside air temperature detecting means is set. Meanwhile, control means for operating the compressor with both the first and second on-off valves closed is provided.

Further, the compressor is a variable capacity type compressor, and immediately before switching from cooling of the freezing room to cooling of the refrigerator compartment, at a certain operating frequency set for each outside air temperature detected by the outside air temperature detecting means. Control means for operating the compressor for a predetermined time is provided.

Further, immediately before switching from cooling of the freezer compartment to cooling of the refrigerator compartment, both the first and second on-off valves are operated for a predetermined time and an operating frequency set for each outside air temperature detected by the outside air temperature detecting means. Control means for operating the compressor in a closed state is provided.

Further, the compressor is a variable capacity type compressor, and immediately before switching from cooling of the freezing room to cooling of the refrigerator compartment,
And control means for operating the compressor at the lowest operating frequency with both the first and second on-off valves closed for a predetermined time immediately before cooling the refrigerator compartment when the compressor is started. It is characterized by having.

Further, a flammable natural refrigerant (such as isobutane or propane) is used as a refrigerant in the cooling cycle.

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 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.

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 isobutane 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 preventing extremely low pressure operation of the compressor at the time of pump down, it is possible to provide a refrigerator which can reduce the load on the compressor and improve the reliability of the cooling system.

[0039]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is directed to a compressor, a condenser, a first on-off valve, a first capillary, and a first capillary disposed in a refrigerator compartment. An evaporator, a second on-off valve, a second capillary, and a second evaporator disposed in a freezing chamber, wherein the compressor, the condenser, the first capillary, and the first A closed loop is formed with the evaporator, and the second capillary, the second evaporator, and the check valve are connected in parallel with the first capillary and the first evaporator, The cooling of the refrigerating compartment and the freezing compartment is performed independently of each other by switching the flow of the refrigerant by the first and second on-off valves, and immediately before switching from the cooling of the freezing compartment to the cooling of the refrigerating compartment. ,
And control means for operating (pump-down) the compressor with both the first and second on-off valves closed for a predetermined period of time immediately before cooling the refrigerator compartment when the compressor is started. It is characterized by having.

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.

Further, since the refrigerant can be used efficiently from the above results, the amount of the refrigerant can be reduced.

In the above description, the first and second on-off valves are used as means for switching the flow of the refrigerant. However, the flow paths to the first and second capillaries 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.

According to a second aspect of the present invention, there is provided an evaporating temperature detecting means for detecting an evaporating temperature of the second evaporator. Immediately before cooling the refrigerating compartment, the compressor is closed in a state where both the first and second on-off valves are closed until the evaporation temperature of the second evaporator detected by the evaporation temperature detecting means reaches a predetermined temperature. And a control means for driving the vehicle.

By regulating the low pressure operation of the compressor at the time of pump down by the evaporation temperature of the second evaporator detected by the evaporating temperature detecting means, it is possible to prevent the extremely low pressure operation of the compressor, and The burden on the machine can be reduced, and the reliability of the cooling system can be improved.

Although the description has been given of the example in which the evaporating temperature detecting means is used as the means for detecting the evaporating temperature of the second evaporator,
The same effect can be obtained by using a defrost end temperature detecting means which is generally used to detect the defrost end temperature of the evaporator.

According to a third aspect of the present invention, the temperature is set for each evaporation temperature of the second evaporator immediately before switching from cooling of the freezing compartment to cooling of the refrigerator compartment, which is detected by the evaporation temperature detecting means. Control means for operating the compressor with both the first and second on-off valves closed for a predetermined time is provided.

When the compressor is operating under a light load, such as at low outside air temperature or when the temperature in the refrigerator is sufficiently cooled, the evaporation temperature of the second evaporator becomes relatively low. If pump down is performed in this state, the tendency of low pressure operation becomes stronger than in the normal case. Therefore, when the evaporation temperature of the second evaporator immediately before the pump down detected by the evaporation temperature detecting means is relatively low, the time for performing the pump down is made shorter than that in the normal case, so that the extreme Low pressure operation can be prevented, reducing the load on the compressor,
The reliability of the cooling system can be improved.

Further, when the compressor is operated under a high load state, for example, at a high outside air temperature or when the temperature in the refrigerator is high, the evaporation temperature of the second evaporator becomes relatively high, and The tendency of the shortage of the circulation amount of the refrigerant to the first evaporator when switching from the cooling of the refrigerator to the cooling of the refrigerator compartment becomes stronger than in the normal case. Therefore, when the evaporation temperature of the second evaporator immediately before the pump down detected by the evaporation temperature detection means is relatively high,
By making the pump down time longer than usual, it is possible to supply sufficient refrigerant to the first evaporator and increase the cooling efficiency of the refrigerator.

According to a fourth aspect of the present invention, the compressor is a variable capacity type compressor, and the compressor is switched just before switching from cooling the freezing compartment to cooling the refrigerating compartment and immediately before the switching detected by the evaporating temperature detecting means. Control means for operating the compressor for a predetermined time at a certain operation frequency set for each evaporation temperature of the two evaporators is provided.

When the compressor is operating under a light load, such as at low outside air temperature or when the temperature in the refrigerator is sufficiently cooled, the evaporation temperature of the second evaporator becomes relatively low. If pump down is performed in this state, the tendency of low pressure operation becomes stronger than in the normal case. Therefore, when the evaporation temperature of the second evaporator immediately before the pump down detected by the evaporation temperature detecting means is relatively low, the operating frequency of the inverter compressor at the time of pump down is reduced, so that the refrigerant due to the pump down is reduced. By reducing the suction force, 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.

Further, when the compressor is operated under a high load condition, for example, at a high outside air temperature or when the temperature in the refrigerator is high, the evaporation temperature of the second evaporator becomes relatively high, and The tendency of the shortage of the circulation amount of the refrigerant to the first evaporator when switching from the cooling of the refrigerator to the cooling of the refrigerator compartment becomes stronger than in the normal case. Therefore, when the evaporation temperature of the second evaporator immediately before the pump down detected by the evaporation temperature detection means is relatively high,
By increasing the operating frequency of the inverter compressor at the time of pump down, it is possible to supply sufficient refrigerant to the first evaporator and increase the cooling efficiency of the refrigerator by increasing the suction force of the refrigerant due to the pump down. .

According to a fifth aspect of the present invention, immediately before switching from cooling of the freezing compartment to cooling of the refrigerator compartment, the temperature is set for each evaporation temperature of the second evaporator immediately before the switching detected by the evaporation temperature detecting means. At a given time and operating frequency,
Control means for operating the compressor in a state in which both the second on-off valves are closed is provided.

When the compressor is operating under a light load, such as at low outside air temperature or when the temperature in the refrigerator is sufficiently cooled, the evaporation temperature of the second evaporator becomes relatively low. If pump down is performed in this state, the tendency of low pressure operation becomes stronger than in the normal case. Therefore, when the evaporation temperature of the second evaporator immediately before the pump down detected by the evaporation temperature detecting means is relatively low, the time for performing the pump down is shortened as compared with the normal case, and the inverter at the time of the pump down is set. By lowering the operating frequency of the compressor, weakening the suction power of the refrigerant due to pump down can prevent extremely low pressure operation of the compressor, reducing the load on the compressor and improving the reliability of the cooling system. It becomes possible.

Further, when the compressor is operated under a high load condition, for example, at a high outside air temperature or when the temperature in the refrigerator is high, the evaporation temperature of the second evaporator becomes relatively high, and The tendency of the shortage of the circulation amount of the refrigerant to the first evaporator when switching from the cooling of the refrigerator to the cooling of the refrigerator compartment becomes stronger than in the normal case. Therefore, when the evaporation temperature of the second evaporator immediately before the pump down detected by the evaporation temperature detection means is relatively high,
By making the pump down time longer than usual and increasing the operating frequency of the inverter compressor at the time of pump down to increase the suction power of the refrigerant due to the pump down, a sufficient amount for the first evaporator is obtained. Supply refrigerant,
The cooling efficiency of the refrigerator can be improved.

According to a sixth aspect of the present invention, there is provided a low pressure detecting means for detecting the pressure of the refrigerant flowing into the compressor, immediately before switching from cooling of the freezing compartment to cooling of the refrigerator compartment, and at the time of starting the compressor. Immediately before cooling the refrigerating chamber, the control means for operating the compressor with both the first and second on-off valves closed until the pressure detected by the low pressure detection means reaches a predetermined pressure. It is characterized by having.

By regulating the low pressure operation of the compressor at the time of pump down by the pressure detected by the low pressure detection means, it is possible to prevent the extremely low pressure operation of the compressor,
The load on the compressor can be reduced, and the reliability of the cooling system can be improved.

According to a seventh aspect of the present invention, the first and second pressures are set for a predetermined time set immediately before switching from cooling of the freezing compartment to cooling of the refrigerating compartment for a predetermined time immediately before the switching detected by the low pressure detection means. Control means for operating the compressor in a state in which both the second on-off valves are closed is provided.

When the compressor is operating under a light load condition, such as at low outside air temperature or when the temperature in the refrigerator is sufficiently cooled, the pressure of the refrigerant flowing into the compressor becomes relatively low. If pump down is performed in this state, the tendency of low pressure operation becomes stronger than in the normal case. Therefore, when the pressure immediately before the pump down detected by the low-pressure pressure detecting means is relatively low, it is possible to prevent an extremely low-pressure operation of the compressor by shortening the time for performing the pump-down compared to the normal case. Thus, the load on the compressor can be reduced, and the reliability of the cooling system can be improved.

Further, when the compressor is operating under a high load condition, such as at a high outside temperature or when the temperature in the refrigerator is high, the pressure of the refrigerant flowing into the compressor becomes relatively high, and The tendency of the shortage of the circulation amount of the refrigerant to the first evaporator when switching from the cooling of the refrigerator to the cooling of the refrigerator compartment becomes stronger than in the normal case. Therefore, when the pressure immediately before the pump down detected by the low pressure detection means is relatively high, the time for performing the pump down is set longer than in the normal case, so that sufficient refrigerant is supplied to the first evaporator. In addition, the cooling efficiency of the refrigerator can be improved.

According to an eighth aspect of the present invention, the compressor is a variable capacity compressor, and the pressure detected by the low pressure detection means immediately before switching from cooling of the freezing room to cooling of the refrigerator compartment is detected. Control means for operating the compressor for a predetermined time at a separately set operation frequency is provided.

When the compressor is operating at a light load, such as at low outside air temperature or when the temperature in the refrigerator is sufficiently cooled, the pressure of the refrigerant flowing into the compressor becomes relatively low. If pump down is performed in this state, the tendency of low pressure operation becomes stronger than in the normal case. Therefore, when the pressure immediately before the pump down detected by the low-pressure pressure detecting means is relatively low, the operating frequency of the inverter compressor at the time of the pump down is reduced to weaken the suction force of the refrigerant due to the pump down, thereby reducing the compression. 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.

When the compressor is operating under a high load, such as at a high outside temperature or when the temperature in the refrigerator is high, the pressure of the refrigerant flowing into the compressor becomes relatively high, and The tendency of the shortage of the amount of refrigerant circulated to the first evaporator when switching from the cooling of the refrigerator to the cooling of the refrigerator compartment becomes stronger. Therefore, when the pressure immediately before the pump down detected by the low pressure pressure detecting means is relatively high, the operating frequency of the inverter compressor at the time of pump down is increased to increase the suction power of the refrigerant due to the pump down. A sufficient refrigerant can be supplied to one evaporator, and the cooling efficiency of the refrigerator can be increased.

According to a ninth aspect of the present invention, immediately before switching from cooling of the freezing compartment to cooling of the refrigerator compartment, the low frequency pressure detection means detects a predetermined time and operating frequency set for each pressure immediately before the switching. Control means for operating the compressor with both the first and second on-off valves closed is provided.

When the compressor is operating under a light load, such as at low outside air temperature or when the temperature in the refrigerator is sufficiently cooled, the pressure of the refrigerant flowing into the compressor becomes relatively low. If pump down is performed in this state, the tendency of low pressure operation becomes stronger than in the normal case. Therefore, when the pressure immediately before the pump down detected by the low pressure pressure detecting means is relatively low, the time for performing the pump down is made shorter than usual, and the operating frequency of the inverter compressor at the time of the pump down is reduced. Thus, by weakening the suction force of the refrigerant due to the pump down, 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.

Further, when the compressor is operated under a high load condition, such as at a high outside air temperature or when the temperature in the refrigerator is high, the pressure of the refrigerant flowing into the compressor becomes relatively high, and The tendency of the shortage of the amount of refrigerant circulated to the first evaporator when switching from the cooling of the refrigerator to the cooling of the refrigerator compartment becomes stronger. Therefore, when the pressure immediately before the pump down detected by the low pressure detecting means is relatively high, the time for performing the pump down is made longer than usual, and the operating frequency of the inverter compressor at the time of the pump down is increased. Thus, by increasing the suction power of the refrigerant due to the pump down, a sufficient refrigerant is supplied to the first evaporator, and the cooling efficiency of the refrigerator can be increased.

According to a tenth aspect of the present invention, there is provided an outside air temperature detecting means for detecting an outside air temperature, and the outside air temperature detected by the outside air temperature detected by the outside air temperature detecting means immediately before switching from cooling of the freezing compartment to cooling of the refrigerator compartment. Control means for operating the compressor in a state where both the first and second on-off valves are closed for a set predetermined time period is provided.

When the compressor is operating under a light load condition, such as at a low outside air temperature, the pressure of the refrigerant flowing into the compressor becomes relatively low. The tendency of low pressure operation becomes stronger than that. Therefore, when the outside air temperature detected by the outside air temperature detecting means is low, by making the pump down time shorter than usual, it is possible to prevent an extremely low pressure operation of the compressor. This burden can be reduced, and the reliability of the cooling system can be improved.

Further, when the compressor is operated under a high load condition such as at a high outside air temperature, the pressure of the refrigerant flowing into the compressor becomes relatively high. The tendency of the shortage of the refrigerant circulation amount to the first evaporator at the time of switching to is increased. Therefore, when the outside air temperature detected by the outside air temperature detecting means is high, the pump down time is made longer than in the normal case, thereby increasing the suction power of the refrigerant due to the pump down, thereby achieving the first evaporation. It becomes possible to supply sufficient refrigerant to the vessel and increase the cooling efficiency of the refrigerator compartment.

According to an eleventh aspect of the present invention, the compressor is a variable capacity compressor, and is set for each outside air temperature detected by the outside air temperature detecting means immediately before switching from cooling of the freezing room to cooling of the refrigerator compartment. Control means for operating the compressor at a given operating frequency for a predetermined time.

When the compressor is operating under a light load condition, such as at a low outside air temperature, the pressure of the refrigerant flowing into the compressor is relatively low. The tendency of low pressure operation becomes stronger than that. Therefore, when the outside air temperature detected by the outside air temperature detecting means is low, the operating frequency of the inverter compressor at the time of pump down is reduced to weaken the suction force of the refrigerant due to the pump down, thereby reducing the extremely low pressure of the compressor. Operation can be prevented, the load on the compressor can be reduced, and the reliability of the cooling system can be improved.

Further, when the compressor is operating under a high load condition, such as at a high outside air temperature, the pressure of the refrigerant flowing into the compressor becomes relatively high. The tendency of the shortage of the refrigerant circulation amount to the first evaporator at the time of switching to is increased. Therefore, when the outside air temperature detected by the outside air temperature detecting means is high, the operating frequency of the inverter compressor at the time of pump down is increased to increase the suction power of the refrigerant due to the pump down, thereby allowing the first evaporator to operate. It is possible to supply sufficient refrigerant and increase the cooling efficiency of the refrigerator compartment.

According to the twelfth aspect, immediately before switching from cooling of the freezing compartment to cooling of the refrigerating compartment, the first and the second predetermined times and operating frequencies set by the outside air temperature detected by the outside air temperature detecting means are set. Control means for operating the compressor in a state in which both the second on-off valves are closed is provided.

When the compressor is operating under a light load condition, such as when the outside air temperature is low, the pressure of the refrigerant flowing into the compressor becomes relatively low. The tendency of low pressure operation becomes stronger than that. Therefore, when the outside air temperature detected by the outside air temperature detecting means is low, the pump down time is made shorter than in the normal case and the operating frequency of the inverter compressor at the time of pump down is reduced, so that the pump down time is reduced. By reducing the suction power of the refrigerant by the above, 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.

When the compressor is operating under a high load, such as at a high outside air temperature, the pressure of the refrigerant flowing into the compressor becomes relatively high. The tendency of the shortage of the refrigerant circulation amount to the first evaporator at the time of switching to is increased. Therefore, when the outside air temperature detected by the outside air temperature detecting means is high, the pump down time is made longer than in the normal case, and the pump down time is increased by increasing the operating frequency of the inverter compressor at the time of pump down. By increasing the suction force of the refrigerant by the above, it is possible to supply a sufficient refrigerant to the first evaporator and to increase the cooling efficiency of the refrigerator compartment.

According to a thirteenth aspect of the present invention, the compressor is a variable capacity compressor, and the cooling of the refrigerator compartment is performed immediately before switching from cooling the freezing compartment to cooling the refrigerator compartment, and when the compressor is started. Immediately before the operation, the control means is provided for operating the compressor at an operation frequency at which the speed becomes the lowest when the first and second on-off valves are both closed for a predetermined time.

By operating the compressor at the lowest operating frequency when the pump is down, the compressor is operated at the lowest operating frequency to reduce the suction power of the refrigerant due to the pump down, thereby preventing the compressor from operating at an extremely low pressure. Thus, the load on the compressor can be reduced, and the reliability of the cooling system can be improved.

The invention according to claim 14 is characterized in that a flammable natural refrigerant (such as isobutane or propane) is used as the refrigerant in the cooling cycle.

From the above results, it is possible to reduce the amount of the refrigerant because the refrigerant can be used efficiently by performing the pump-down operation. In particular, when a flammable refrigerant (such as isobutane or propane) is used, the amount of the refrigerant is reduced. It is possible to increase the safety at the time of leakage.

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 an 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, and a second on-off valve 1
1, a second capillary 8, and a second evaporator 5 disposed in the freezer 6, 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.

Reference numeral 12 denotes a refrigerator box, in which a refrigerator compartment 4 which is a relatively high-temperature compartment is disposed in an upper portion, and a freezing compartment 6 which is a relatively low-temperature compartment is disposed in a lower portion. 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 13.

The refrigerating compartment 4 and freezing compartment 6 are provided with temperature detecting means (not shown) for detecting the temperature in the compartment, respectively, and control the compressor 1, the first on-off valve 10 and the second on-off valve 11. Control means (not shown).

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.

During the cooling of the freezing compartment 6, the first on-off valve 10 is in a closed state, and the second on-off valve 11 is in an open state. The high-temperature and high-pressure refrigerant discharged by the operation of the compressor 1 is condensed and liquefied by the condenser 2, reduced in pressure by the second capillary 8 through the second on-off valve 11, and then to the second evaporator 5. The freezing compartment 6 is cooled by flowing in and evaporating.

When the temperature detecting means of the refrigerator 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 both the first on-off valve 10 and the second on-off valve 11 are closed.

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 is released (T2).

The refrigerant is decompressed by the first capillary 7 through the compressor 1, the condenser 2, and the first on-off valve 10, and then flows into the first evaporator 3, where it is refrigerated by evaporating and evaporating. The cooling of the chamber 4 is performed.

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 opening / closing valve 10 is closed and the second opening / closing valve 11 is closed.
Is released (T3).

The refrigerant is decompressed by the second capillary 8 via the compressor 1, the condenser 2, the second on-off valve 11, and then flows into the second evaporator 5, where the refrigerant is evaporated and vaporized to be frozen. The cooling of the chamber 6 is performed.

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 on-off valve 10 and the second on-off valve 11 are both opened, and the compressor 1 is stopped (T4).

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), and the compressor 1 is operated (pump down) (T5).

After the pump down, the first on-off valve 10 is opened while the second on-off valve 11 is closed to cool the refrigerator compartment 4 (T6).

Further, while the compressor 1 is stopped, the temperature inside the freezer compartment 6 rises sharply, and before the temperature detecting device of the refrigerator compartment 4 reaches a predetermined temperature, the temperature detecting device of the freezer compartment 6 is cooled. If the control means detects that the temperature exceeds a predetermined temperature, the control means receives this signal, closes the first on-off valve 10 with the second on-off valve 11 opened, and sets the compressor 1
Is performed to cool the freezing room 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 where both the on-off valves 11 are closed, and the pressure in the compressor 1 is compared with that in the normal operation by performing a pump-down in which the refrigerant is forcibly moved from the low pressure side to the high pressure side. As a result, the pressure becomes low, and the refrigerant remaining in the second evaporator 5 can be expelled 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 is quickly supplied to the first evaporator 3, 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.

(Embodiment 2) FIG. 3 is a schematic diagram of a refrigerator cooling system according to a second embodiment of the present invention, and FIG. 4 is a time chart of the embodiment.

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

Reference numeral 14 denotes an evaporating temperature detecting means for detecting the evaporating temperature of the second evaporator 5.

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.

When the temperature detecting means of the refrigerator 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 both the first on-off valve 10 and the second on-off valve 11 are closed, and stays in the second evaporator 5. The evaporated refrigerant is evaporated and vaporized, the pressure of the refrigerant flowing into the compressor 1 rapidly decreases, and the evaporation temperature of the second evaporator 5 detected by the evaporation temperature detecting means 14 decreases to a predetermined temperature (t1). Reach

When the evaporating temperature reaches a predetermined temperature (t1), the first on-off valve 1 is kept closed with the second on-off valve 11 closed.
0 is released, and the refrigerator compartment 4 is cooled (T2).

When the temperature detecting means of the freezer compartment 6 detects that the temperature has exceeded 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 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 on-off valve 10 and the second on-off valve 11 are both opened, and the compressor 1 is stopped (T4).

While the compressor 1 is stopped, the refrigerant stays in the second evaporator 5 because the second evaporator 5 disposed in the freezer 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 on-off valve 10 and the second on-off valve 11 are closed, and the compressor 1 is operated (pump down) (T
5).

By performing the pump-down operation, the refrigerant retained in the second evaporator 5 is evaporated and vaporized, and the pressure of the refrigerant flowing into the compressor 1 is rapidly reduced.
, The evaporation temperature of the second evaporator 5 reaches a predetermined temperature (t1) while decreasing.

When the evaporating temperature reaches a predetermined temperature (t1), the first on-off valve 1 is closed with the second on-off valve 11 closed.
0 is released, and the refrigerator compartment 4 is cooled (T6).

Further, while the compressor 1 is stopped, the temperature inside the freezer compartment 6 rises sharply, and before the temperature detecting device of the refrigerator compartment 4 reaches a predetermined temperature, the temperature detecting device of the freezer compartment 6 is cooled. If the control means detects that the temperature exceeds a predetermined temperature, the control means receives this signal, closes the first on-off valve 10 with the second on-off valve 11 opened, and sets the compressor 1
Is performed to cool the freezing room 6.

The low pressure operation of the compressor 1 at the time of pump down is regulated by the evaporation temperature of the second evaporator 5 detected by the evaporation temperature detecting means 14 to prevent the extremely low pressure operation of the compressor 1. Thus, the load on the compressor 1 can be reduced, and the reliability of the cooling system can be improved.

(Embodiment 3) FIG. 5 is a time chart of an embodiment 3 of the present invention.

The detailed description of the same components as those in the second 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 in a closed state, and the second on-off valve 11 is in an open state.

When the temperature detecting means of the refrigerator 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) with both the first on-off valve 10 and the second on-off valve 11 closed.

The time for performing the pump-down is set by the control means for each evaporation temperature of the second evaporator 5 immediately before the pump-down detected by the evaporation temperature detecting means 14.

For example, when the evaporation temperature of the second evaporator 5 immediately before the pump down detected by the evaporation temperature detecting means 14 is lower than the evaporation temperature during the normal operation, the pump down time (Te2) during the normal operation. Shorter time (Te1)
If it is high, it is a long time (Te3) (Te1 <
Te2 <Te3).

When the pump down set as described above is completed, the first on-off valve 10 is opened with the second on-off valve 11 closed, and the refrigerator compartment 4 is cooled (T2).

When the compressor 1 is operating under a light load, such as at low outside air temperature or when the temperature in the refrigerator is sufficiently cooled, the evaporation temperature of the second evaporator 5 becomes relatively low. If the pump is down in that state, the tendency of the low pressure operation becomes stronger than in the normal case. Therefore, when the evaporating temperature of the second evaporator 5 immediately before the pump down detected by the evaporating temperature detecting means 14 is relatively low, the time for performing the pump down is shortened as compared with the normal case, so that the compressor 1 can be prevented from operating at extremely low pressure, the load on the compressor 1 can be reduced, and the reliability of the cooling system can be improved.

Further, when the compressor 1 is operated under a high load state, for example, at a high outside air temperature or when the temperature in the refrigerator is high, the evaporation temperature of the second evaporator 5 becomes relatively high. When switching from cooling the freezer compartment 6 to cooling the refrigerator compartment 4, the tendency of the shortage of the refrigerant circulation amount to the first evaporator 3 becomes stronger than in the normal case. Therefore, when the evaporating temperature of the second evaporator 5 immediately before the pump down detected by the evaporating temperature detecting means 14 is relatively high, the time for performing the pump down is made longer than in the normal case, so that the first Thus, it is possible to supply sufficient refrigerant to the evaporator 3 to increase the cooling efficiency of the refrigerator compartment 4.

(Embodiment 4) FIG. 6 is a schematic diagram of a refrigerator cooling system according to an embodiment 4 of the present invention, and FIG. 7 is a time chart of the embodiment.

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

An inverter compressor 15 is a variable capacity compressor.

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.

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 15 is operating (pump down) with both the first on-off valve 10 and the second on-off valve 11 closed.

The operating frequency of the inverter compressor 15 during pump down is set by the control means for each evaporation temperature of the second evaporator 5 immediately before pump down detected by the evaporation temperature detection means 14.

For example, when the evaporation temperature of the second evaporator 5 immediately before the pump down detected by the evaporation temperature detecting means 14 is lower than the evaporation temperature in the normal operation, the inverter compressor 15 operates the pump in the normal operation. The pump-down operation is performed at an operation frequency (H1) lower than the operation frequency (H2) during the down operation, and when it is higher, the pump operation is performed at a high operation frequency (H3) (H1 <H2 <H3).

When the pump down set as described above is completed, the first on-off valve 10 is opened with the second on-off valve 11 closed, and the refrigerator compartment 4 is cooled (T2).

When the compressor 15 is operated with a light load, such as at low outside air temperature or when the temperature in the refrigerator is sufficiently cooled, the evaporation temperature of the second evaporator 5 becomes relatively low. If the pump is down in that state, the tendency of the low pressure operation becomes stronger than in the normal case. Therefore, the evaporating temperature detecting means 14
When the evaporation temperature of the second evaporator 5 immediately before the pump down detected by the above is relatively low, the operating frequency of the inverter compressor 15 at the time of the pump down is reduced to weaken the suction power of the refrigerant due to the pump down. Compressor 1
5 can be prevented from operating at an extremely low pressure, the load on the compressor 15 can be reduced, and the reliability of the cooling system can be improved.

Further, when the compressor 15 is operated under a high load state, for example, at a high outside air temperature or when the temperature in the refrigerator is high,
The evaporation temperature of the second evaporator 5 becomes relatively high, and the tendency of the shortage of the amount of the refrigerant circulated to the first evaporator 3 when switching from cooling the freezing compartment 6 to cooling the refrigerator compartment 4 is higher than usual. Also become stronger. Therefore, when the evaporation temperature of the second evaporator 5 immediately before the pump down detected by the evaporation temperature detecting means 14 is relatively high, the operating frequency of the inverter compressor 15 at the time of the pump down is increased to thereby reduce the pump down. By increasing the suction power of the refrigerant by the above, a sufficient refrigerant can be supplied to the first evaporator 3 and the cooling efficiency of the refrigerator compartment 4 can be increased.

(Embodiment 5) FIG. 8 is a time chart of a fifth embodiment of the present invention.

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

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.

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 15 is in operation (pump down) while the first on-off valve 10 and the second on-off valve 11 are both closed.

The operating frequency of the inverter compressor 15 during the pump down and the pump down time are set by the control means for each evaporation temperature of the second evaporator 5 immediately before the pump down detected by the evaporation temperature detection means 14. ing.

For example, when the evaporation temperature of the second evaporator 5 immediately before the pump down detected by the evaporation temperature detecting means 14 is lower than the evaporation temperature in the normal operation, the inverter compressor 15 operates the pump in the normal operation. At an operation frequency (H1) lower than the operation frequency (H2) during the down time, a time (Te) shorter than the pump down time (Te2) during the normal operation.
1) Pump down is performed, and if high, the pump down is performed at a high operating frequency (H3) for a long time (Te3) (H1 <H2 <H3, Te1 <Te2 <Te3).

When the pump down set as described above is completed, the first on-off valve 10 is opened with the second on-off valve 11 closed, and the refrigerator compartment 4 is cooled (T2).

When the compressor 15 is operating under a light load, such as at low outside air temperature or when the temperature in the refrigerator is sufficiently cooled, the evaporation temperature of the second evaporator 5 becomes relatively low. If the pump is down in that state, the tendency of the low pressure operation becomes stronger than in the normal case. Therefore, the evaporating temperature detecting means 14
When the evaporation temperature of the second evaporator 5 immediately before the pump down detected by the above is relatively low, the operating frequency of the inverter compressor 15 at the time of pump down is reduced and the time for performing the pump down is shortened. Extremely low pressure operation of the compressor 15 can be prevented by weakening the suction force of the refrigerant due to the pump down, the load on the compressor 15 can be reduced, and the reliability of the cooling system can be improved.

When the compressor 15 is operating under a high load, such as at a high outside temperature or when the temperature in the refrigerator is high,
The evaporation temperature of the second evaporator 5 becomes relatively high, and the tendency of the shortage of the amount of the refrigerant circulated to the first evaporator 3 when switching from cooling the freezing compartment 6 to cooling the refrigerator compartment 4 is higher than usual. Also become stronger. Therefore, when the evaporation temperature of the second evaporator 5 immediately before the pump down detected by the evaporation temperature detecting means 14 is relatively high, the operation frequency of the inverter compressor 15 at the time of pump down is increased and the pump down is performed. By increasing the time, a sufficient refrigerant is supplied to the first evaporator 3 by increasing the suction power of the refrigerant due to the pump down, and the cooling efficiency of the refrigerator compartment 4 can be increased.

(Embodiment 6) FIG. 9 is a schematic diagram of a refrigerator cooling system according to a sixth embodiment of the present invention, and FIG. 10 is a time chart of the sixth embodiment of the present invention.

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

Reference numeral 16 denotes a low pressure detecting means for detecting the pressure of the refrigerant flowing into the compressor 1. While cooling the freezer 6,
The first on-off valve 10 is in a closed state, and the second on-off valve 11 is in an open state. The high-temperature and high-pressure refrigerant discharged by the operation of the compressor 1 is condensed and liquefied by the condenser 2,
After the pressure is reduced by the second capillary 8 via the second on-off valve 11, the second capillary 8 flows into the second evaporator 5, where the freezing chamber 6 is cooled by evaporating.

When the temperature detecting means of the refrigerator 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 both the first on-off valve 10 and the second on-off valve 11 are closed, and stays in the second evaporator 5. The refrigerant thus evaporated is vaporized, and the pressure of the refrigerant flowing into the compressor 1 detected by the low pressure detection means 16 rapidly decreases to reach a predetermined pressure (p1).

When a predetermined pressure (p1) is reached, the first on-off valve 10 is opened with the second on-off valve 11 closed,
The refrigerator compartment 4 is cooled (T2).

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 to cool the freezing compartment 6 (T3).

The refrigerant is depressurized by the second capillary 8 via the compressor 1, the condenser 2, the second on-off valve 11, and then flows into the second evaporator 5, where the refrigerant is evaporated and vaporized to be frozen. The cooling of the chamber 6 is performed.

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 on-off valve 10 and the second on-off valve 11 are both opened, and the compressor 1 is stopped (T4).

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 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 on-off valve 10 and the second on-off valve 11 are closed, and the compressor 1 is operated (pump down) (T
5).

By performing the pump-down operation, the refrigerant retained in the second evaporator 5 is evaporated and vaporized, and the pressure of the refrigerant flowing into the compressor 1 detected by the low-pressure pressure detecting means 16 is reduced rapidly to a predetermined pressure. Is reached (p1).

When a predetermined pressure (p1) is reached, the first on-off valve 10 is opened with the second on-off valve 11 closed,
The refrigerator compartment 4 is cooled (T6).

Further, while the compressor 1 is stopped, the temperature inside the freezing compartment 6 rises sharply, and before the temperature detecting means of the refrigerating compartment 4 reaches a predetermined temperature, the temperature detecting means of the freezing compartment 6 is increased. When the control means detects that the temperature exceeds a predetermined temperature, the control means receives this signal, closes the first on-off valve 10 with the second on-off valve 11 opened, and sets the compressor 1
Is performed to cool the freezing room 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 where 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 is quickly supplied to the first evaporator 3, the amount of circulating refrigerant does not become insufficient, and the refrigerator compartment 4 can be efficiently cooled.

Further, since the refrigerant can be efficiently used based on the above results, the amount of the refrigerant can be reduced.

Further, the compressor 1 at the time of pump down
Is regulated by the pressure of the refrigerant flowing into the compressor 1 detected by the low pressure detection means 16, it is possible to prevent an extremely low pressure operation of the compressor 1, and to reduce the load on the compressor 1. And the reliability of the cooling system can be improved.

(Embodiment 7) FIG. 11 shows a seventh embodiment of the present invention.
6 is a time chart of the embodiment.

Detailed description of the same components as those of the sixth 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.

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.

[0170] The pump down time is determined by the compressor 1 immediately before the pump down detected by the low pressure detection means 16.
Is set by the control means for each pressure of the refrigerant flowing into the air.

For example, when the pressure of the refrigerant flowing into the compressor 1 immediately before the pump down detected by the low pressure pressure detecting means 16 is lower than the pressure during the normal operation, the pump down time (Te2) during the normal operation is used. Is also short (Te1)
If it is high, it is a long time (Te3) (Te1 <
Te2 <Te3).

When the pump down set as described above is completed, the first on-off valve 10 is opened with the second on-off valve 11 closed, and the refrigerator compartment 4 is cooled (T2).

When the compressor 1 is operated with a light load, such as at low outside air temperature or when the temperature in the refrigerator is sufficiently cooled, the pressure of the refrigerant flowing into the compressor 1 becomes relatively low. ,
If pump down is performed in that state, the tendency of low pressure operation becomes stronger than in a normal case. Therefore, the low pressure detection means 1
When the pressure of the refrigerant flowing into the compressor 1 immediately before the pump-down detected by the step 6 is relatively low, the time for performing the pump-down is made shorter than in the normal case, so that the extremely low-pressure operation of the compressor 1 is performed. Can be prevented, the load on the compressor 1 can be reduced, and the reliability of the cooling system can be improved.

Further, when the compressor 1 is operated under a high load condition, for example, at a high outside air temperature or when the temperature in the refrigerator is high, the pressure of the refrigerant flowing into the compressor 1 becomes relatively high. When switching from cooling the freezer compartment 6 to cooling the refrigerator compartment 4, the tendency of the shortage of the refrigerant circulation amount to the first evaporator 3 becomes stronger than in the normal case. Therefore, when the pressure of the refrigerant flowing into the compressor 1 immediately before the pump-down detected by the low-pressure pressure detecting means is relatively high, the time for performing the pump-down is made longer than in the normal case, so that the first It is possible to supply sufficient refrigerant to the evaporator 3 to increase the cooling efficiency of the refrigerator compartment 4.

(Embodiment 8) FIG. 12 shows an eighth embodiment of the present invention.
6 is a time chart of the embodiment.

The detailed description of the same components as those of the sixth 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.

When the temperature detecting means of the refrigerator 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 inverter compressor 15 is in operation (pump down) while both the first on-off valve 10 and the second on-off valve 11 are closed.

The operating frequency of the inverter compressor 15 during the pump down is set by the control means for each pressure detected by the low pressure detection means 16 and flowing into the compressor 15 immediately before the pump down.

For example, when the pressure of the refrigerant flowing into the compressor 15 immediately before the pump-down detected by the low-pressure pressure detecting means 16 is lower than the pressure during the normal operation, the inverter compressor 15 starts the pump-down during the normal operation. Pump-down is performed at an operation frequency (H1) lower than the middle operation frequency (H2), and if higher, pump-down is performed at a higher operation frequency (H3) (H1 <H2 <H3).

When the pump down set as described above is completed, the first on-off valve 10 is opened with the second on-off valve 11 closed, and the refrigerator compartment 4 is cooled (T2).

When the compressor 15 is operated with a light load, such as at low outside air temperature or when the temperature in the refrigerator is sufficiently cooled, the pressure of the refrigerant flowing into the compressor 15 becomes relatively low. If the pump is down in that state, the tendency of the low pressure operation becomes stronger than in the normal case. Therefore, the compressor 15 immediately before the pump down detected by the low pressure detection means 16
When the pressure of the refrigerant flowing into the compressor is relatively low, the operating frequency of the inverter compressor 15 at the time of pump down is reduced, thereby weakening the suction force of the refrigerant due to the pump down, thereby performing extreme low pressure operation of the compressor 15. Thus, the load on the compressor 15 can be reduced, and the reliability of the cooling system can be improved.

Further, when the compressor 15 is operated under a high load state, for example, at a high outside air temperature or when the temperature in the refrigerator is high,
The pressure of the refrigerant flowing into the compressor 15 becomes relatively high, and the tendency of the shortage of the refrigerant circulation amount to the first evaporator 3 when switching from the cooling of the freezing room 6 to the cooling of the refrigerating room 4 is higher than usual. Also become stronger. Therefore, when the pressure of the refrigerant flowing into the compressor 15 immediately before the pump down detected by the low-pressure pressure detecting means 16 is relatively high, the operating frequency of the inverter compressor 15 at the time of pump down is increased to thereby reduce the pump down. By increasing the suction power of the refrigerant by the above, a sufficient refrigerant can be supplied to the first evaporator 3 and the cooling efficiency of the refrigerator compartment 4 can be increased.

(Embodiment 9) FIG. 13 shows a ninth embodiment of the present invention.
6 is a time chart of the embodiment.

The detailed description of the same components as those of the eighth 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.

When the temperature detecting means of the refrigerator 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 inverter compressor 15 is operating (pump down) while the first on-off valve 10 and the second on-off valve 11 are both closed.

The operating frequency of the inverter compressor 15 during the pump down and the time for performing the pump down are determined by the compressor 15 immediately before the pump down detected by the low pressure detection means.
Are set by the control means according to the pressure flowing into the air.

For example, when the pressure of the refrigerant flowing into the compressor 15 immediately before the pump-down detected by the low-pressure pressure detecting means 16 is lower than the pressure during the normal operation, the inverter compressor 15 starts the pump-down during the normal operation. The operation frequency (H1) lower than the medium operation frequency (H2), and the time (Te) shorter than the pump down time (Te2) in the normal operation.
1) Pump down is performed, and if high, the pump down is performed at a high operating frequency (H3) for a long time (Te3) (H1 <H2 <H3, Te1 <Te2 <Te3).

When the pump down set as described above is completed, the first on-off valve 10 is opened while the second on-off valve 11 is closed, and the refrigerator compartment 4 is cooled (T2).

When the compressor 15 is operating under a light load, such as at low outside air temperature or when the temperature in the refrigerator is sufficiently cooled, the pressure of the refrigerant flowing into the compressor 15 becomes relatively low. If the pump is down in that state, the tendency of the low pressure operation becomes stronger than in the normal case. Therefore, the compressor 15 immediately before the pump down detected by the low pressure detection means 16
When the pressure of the refrigerant flowing into the pump is relatively low, the pump down time is made shorter than in the normal case, and the operating frequency of the inverter compressor 15 at the time of pump down is reduced, so that the refrigerant is pumped down. By reducing the suction force, extremely low pressure operation of the compressor 15 can be prevented, the load on the compressor 15 can be reduced, and the reliability of the cooling system can be improved.

Further, when the compressor 15 is operated under a high load state, for example, when the outside air temperature is high or the temperature in the refrigerator is high,
The pressure of the refrigerant flowing into the compressor 15 becomes relatively high, and the tendency of the shortage of the refrigerant circulation amount to the first evaporator 3 when switching from the cooling of the freezing room 6 to the cooling of the refrigerating room 4 is higher than usual. Also become stronger. Therefore, when the pressure of the refrigerant flowing into the compressor 15 immediately before the pump-down detected by the low-pressure pressure detection means 16 is relatively high, the operating frequency of the inverter compressor 15 at the time of the pump-down is increased and the pump-down is performed. By increasing the time, a sufficient refrigerant is supplied to the first evaporator 3 by increasing the suction power of the refrigerant due to the pump down, and the cooling efficiency of the refrigerator compartment 4 can be increased.

(Embodiment 10) FIG. 14 is a schematic diagram of a refrigerator cooling system according to a tenth embodiment of the present invention, and FIG. 15 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.

Reference numeral 17 denotes an outside air temperature detecting means installed outside the refrigerator box 12 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.

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 both the first on-off valve 10 and the second on-off valve 11 are closed.

The time for performing the pump down is set by the control means for each of the outside air temperatures detected by the outside air temperature detecting means 17.

For example, when the outside air temperature detected by the outside air temperature detecting means 17 is low, the time is shorter (Te1) than the pump down time (Te2) during normal operation, and when it is higher, it is long (Te3) ( Te1 <Te2 <Te
3).

When the pump down set as described above is completed, the first on-off valve 10 is opened with the second on-off valve 11 closed, and the refrigerator compartment 4 is cooled (T2).

When the compressor 1 is operating under a light load condition, such as at a low outside air temperature, the pressure of the refrigerant flowing into the compressor 1 becomes relatively low.
The tendency of low-pressure operation becomes stronger than usual. Therefore,
When the outside air temperature detected by the outside air temperature detecting means 17 is low, an extremely low pressure operation of the compressor 1 can be prevented by shortening the time for performing the pump down as compared with a normal case. This burden can be reduced, and the reliability of the cooling system can be improved.

Further, when the compressor 1 is operated under a high load condition such as when the outside air temperature is high, the pressure of the refrigerant flowing into the compressor 1 becomes relatively high, When switching to the cooling of the chamber 4, the tendency of the shortage of the refrigerant circulation amount to the first evaporator 3 increases. Therefore, when the outside air temperature detected by the outside air temperature detection means 17 is high, the pump down time is made longer than in the normal case to enhance the suction power of the refrigerant due to the pump down, thereby achieving the first It is possible to supply a sufficient refrigerant to the evaporator 3 and increase the cooling efficiency of the refrigerator compartment 4.

(Embodiment 11) FIG. 16 is a time chart of an embodiment according to claim 11 of the present invention.

The detailed description of the same components as those of the tenth 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.

When the temperature detecting means of the refrigerator 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 inverter compressor 15 is in operation (pump down) while both the first on-off valve 10 and the second on-off valve 11 are closed.

The operating frequency of the inverter compressor 15 during the pump down is set by the control means for each outside air temperature detected by the outside air temperature detection means 17.

For example, when the outside air temperature detected by the outside air temperature detecting means 17 is low, the inverter compressor 15 pumps down at the operation frequency (H1) lower than the operation frequency (H2) during the pump down during normal operation. And if it is high, pump down is performed at a high operating frequency (H3) (H1 <H2 <H3).

When the pump down set as described above is completed, the first on-off valve 10 is opened with the second on-off valve 11 closed, and the refrigerator compartment 4 is cooled (T2).

When the compressor 15 is operating under a light load, such as when the outside air temperature is low, the pressure of the refrigerant flowing into the compressor 15 becomes relatively low. The tendency of low pressure operation becomes stronger than in the case of. Therefore, when the outside air temperature detected by the outside air temperature detecting means 17 is low, the inverter compressor 15
By lowering the operating frequency of the compressor, by weakening the suction force of the refrigerant due to the pump down, extremely low pressure operation of the compressor 15 can be prevented, the load on the compressor 15 can be reduced, and the reliability of the cooling system can be improved. It becomes possible.

Further, when the compressor 15 is operated under a high load condition, such as when the outside air temperature is high, the pressure of the refrigerant flowing into the compressor 15 becomes relatively high. When switching to the cooling of the chamber 4, the tendency of the shortage of the refrigerant circulation amount to the first evaporator 3 increases. Therefore, when the outside air temperature detected by the outside air temperature detecting means 17 is high, the operating frequency of the inverter compressor 15 at the time of pump down is increased to increase the suction power of the refrigerant due to the pump down, thereby achieving the first evaporation. It is possible to supply a sufficient refrigerant to the vessel 3 and increase the cooling efficiency of the refrigerator compartment 4.

(Embodiment 12) FIG. 17 is a time chart of a twelfth embodiment of the present invention.

A detailed description of the same components as those of the fourth 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.

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

At this time, the inverter compressor 15 is operating (pump down) while both the first on-off valve 10 and the second on-off valve 11 are closed.

The operating frequency of the inverter compressor 15 during the pump down and the time for performing the pump down are set by the control means for each outside air temperature detected by the outside air temperature detection means 17.

For example, when the outside air temperature detected by the outside air temperature detecting means 17 is low, the inverter compressor 15 operates at the operating frequency (H1) lower than the operating frequency (H2) during the pump down during the normal operation, and Pump down is performed for a time (Te1) shorter than the pump down time (Te2) during operation, and when higher, pump down is performed at a higher operation frequency (H3) for a longer time (Te3) (H1 <H2 <H).
3, Te1 <Te2 <Te3).

When the pump down set as described above is completed, the first on-off valve 10 is opened with the second on-off valve 11 closed, and the refrigerator compartment 4 is cooled (T2).

When the compressor 15 is operating under a light load condition, such as at low outside air temperature, the pressure of the refrigerant flowing into the compressor 15 becomes relatively low. The tendency of low pressure operation becomes stronger than in the case of. Therefore, when the outside air temperature detected by the outside air temperature detecting means 17 is low, the pump down time is made shorter than usual and the operating frequency of the inverter compressor 15 at the time of pump down is reduced. Extremely low pressure operation of the compressor 15 can be prevented by weakening the suction force of the refrigerant due to the pump down, the load on the compressor 15 can be reduced, and the reliability of the cooling system can be improved.

Further, when the compressor 15 is operated under a high load condition, for example, at a high outside air temperature, the pressure of the refrigerant flowing into the compressor 15 becomes relatively high, When switching to the cooling of the chamber 4, the tendency of the shortage of the refrigerant circulation amount to the first evaporator 3 increases. Therefore, when the outside air temperature detected by the outside air temperature detecting means 17 is high, the pump down time is made longer than usual, and the operating frequency of the inverter compressor 15 at the time of pump down is increased. By increasing the suction power of the refrigerant due to the pump down, a sufficient refrigerant is supplied to the first evaporator 3 and the cooling efficiency of the refrigerator compartment 4 can be increased.

(Embodiment 13) FIG. 18 is a time chart of the embodiment 13 of the present invention.

The same components as those in the fourth 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.

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 inverter compressor 15 is in operation (pump down) while both the first on-off valve 10 and the second on-off valve 11 are closed.

During the pump down, the inverter compressor 15 is operated at the lowest operating frequency.

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 is released, and the refrigerator compartment 4 is cooled (T2).

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 to cool the freezing compartment 6 (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 on-off valve 10 and the second on-off valve 11 are both opened and closed, and the compressor 15 is stopped (T4).

While the compressor 15 is stopped, the refrigerant stays in the second evaporator 5 because the second evaporator 5 disposed in the freezing room 6 has the lowest temperature in the refrigeration cycle.

If the temperature in the refrigerator compartment 4 rises while the compressor 15 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 on-off valve 10 for a predetermined time (Ta).
Then, the second on-off valve 11 is closed, and the compressor 15 is operated (pump down) (T5).

While the pump is down, the inverter compressor 15 is operated at the lowest operating frequency.

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

Further, while the compressor 15 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 and the second on-off valve 11
Is opened, the first on-off valve 10 is closed, the compressor 15 is operated, and the freezing compartment 6 is cooled.

The low pressure operation of the compressor 15 at the time of pump down is performed by operating the compressor 15 at the lowest operating frequency, thereby weakening the suction power of the refrigerant due to the pump down, thereby reducing the extremely low pressure operation of the compressor 15. Thus, the load on the compressor 15 can be reduced, and the reliability of the cooling system can be improved.

(Embodiment 14) A flammable natural refrigerant (such as isobutane or propane) not shown is used as the refrigerant in the cooling cycle.
Is used.

By performing the pump down, the refrigerant can be used efficiently, so that the amount of the refrigerant can be reduced. In particular, when a flammable refrigerant (such as isobutane or propane) is used, the reduction in the amount of the refrigerant enables the safety at the time of refrigerant leakage. Performance can be improved.

[0243]

According to the present invention, the compressor is operated in a state where the first and second on-off valves are both 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.

In addition, 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 isobutane 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 preventing extremely low pressure operation of the compressor at the time of pump 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 schematic diagram of a refrigerator cooling system according to a second embodiment of the present invention.

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

FIG. 5 is a time chart showing a third embodiment of the present invention.

FIG. 6 is a schematic diagram of a refrigerator cooling system according to a fourth embodiment of the present invention.

FIG. 7 is a time chart showing a fourth embodiment of the present invention.

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

FIG. 9 is a schematic diagram of a refrigerator cooling system according to a sixth embodiment of the present invention.

FIG. 10 is a time chart showing a sixth embodiment of the present invention.

FIG. 11 is a time chart showing a seventh embodiment of the present invention.

FIG. 12 is a time chart showing an embodiment of claim 8 of the present invention.

FIG. 13 is a time chart showing a ninth embodiment of the present invention.

FIG. 14 is a schematic diagram of a cooling system of a refrigerator according to the tenth embodiment of the present invention.

FIG. 15 is a time chart showing an embodiment according to claim 10 of the present invention.

FIG. 16 is a time chart showing an embodiment according to claim 11 of the present invention;

FIG. 17 is a time chart showing a twelfth embodiment of the present invention.

FIG. 18 is a time chart showing an embodiment according to claim 13 of the present invention.

FIG. 19 is a schematic view 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 evaporating temperature detecting means 15 inverter compressor 16 low pressure detecting means 17 outside air temperature detecting means

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F25B 5/02 530 F25B 5/02 530D (72) Inventor Tetsuya Saito 4-chome Takaida Motodori Higashi Osaka City, Osaka Prefecture No. 2-5 Matsushita Refrigeration Co., Ltd. F term (reference) 3L045 AA02 BA01 CA02 DA02 HA02 JA14 LA03 LA06 MA04 MA05 MA09 MA12 NA01 NA16 PA01 PA05

Claims (14)

[Claims] 1. A compressor, a condenser, a first on-off valve,
A first capillary, a first evaporator disposed in a refrigerator compartment, a second on-off valve, a second capillary, and a second evaporator disposed in a freezer compartment, Forming a closed loop with a compressor, the condenser, the first capillary, and the first evaporator, and forming the second capillary so as to be parallel to the first capillary and the first evaporator; And the second evaporator and the check valve are connected to each other,
The cooling of the refrigerating compartment and the freezing compartment is performed independently of each other by switching the flow of the refrigerant by a second on-off valve, immediately before switching from the cooling of the freezing compartment to the cooling of the refrigerating compartment, and the compression. A refrigerator comprising control means for operating the compressor with both the first and second on-off valves closed for a predetermined period of time immediately before cooling the refrigerator compartment at the time of starting the machine. . 2. An evaporating temperature detecting means for detecting an evaporating temperature of the second evaporator, which is provided immediately before switching from cooling of the freezing room to cooling of the refrigerating room and immediately before cooling of the refrigerating room when the compressor is started. Until the evaporation temperature of the second evaporator detected by the evaporation temperature detection means reaches a predetermined temperature,
A refrigerator comprising control means for operating the compressor with both the second on-off valves closed. 3. Immediately before switching from cooling of the freezing compartment to cooling of the refrigerating compartment, the first and the second evaporators for a predetermined period of time set by the evaporation temperature of the second evaporator immediately before the switching detected by the evaporating temperature detecting means. A refrigerator comprising control means for operating the compressor with both the second on-off valves closed. 4. The evaporation temperature of a second evaporator immediately before switching from cooling of a freezing compartment to cooling of a refrigerator compartment, wherein the compressor is a variable capacity type compressor. A refrigerator comprising control means for operating the compressor at a predetermined operating frequency for a predetermined time. 5. Immediately before switching from cooling of the freezing compartment to cooling of the refrigerating compartment, at a predetermined time and an operating frequency set for each evaporation temperature of the second evaporator immediately before the switching detected by the evaporation temperature detecting means. A refrigerator comprising control means for operating a compressor with both first and second on-off valves closed. 6. A low-pressure pressure detecting means for detecting a pressure of a refrigerant flowing into a compressor, wherein the refrigerator is cooled immediately before switching from cooling of a freezing room to cooling of a refrigerator, and when starting up the compressor. Immediately before, there is provided control means for operating the compressor with both the first and second on-off valves closed until the pressure detected by the low-pressure pressure detection means reaches a predetermined pressure. refrigerator. 7. Immediately before switching from cooling of the freezing compartment to cooling of the refrigerator compartment, the first and second on-off valves are both set for a predetermined time set for each pressure immediately before the switching detected by the low pressure detection means. A refrigerator comprising control means for operating a compressor in a closed state. 8. An operating frequency which is set for each pressure immediately before switching from cooling of a freezing compartment to cooling of a refrigerator compartment, wherein the compressor is a variable capacity type compressor. And a control means for operating the compressor for a predetermined time. 9. The first and second on-off valves immediately before switching from cooling of the freezing compartment to cooling of the refrigerating compartment at a predetermined time and operating frequency set for each pressure immediately before the switching detected by the low pressure detection means. A refrigerator comprising control means for operating a compressor with both of them closed. 10. An outside air temperature detecting means for detecting an outside air temperature, wherein immediately before switching from cooling of the freezing room to cooling of the refrigerator compartment, a predetermined time set for each of the outside air temperatures detected by the outside air temperature detecting means is provided. A refrigerator comprising control means for operating the compressor while the first and second on-off valves are both closed. 11. The compressor is a variable capacity type compressor,
Immediately before switching from cooling of the freezer compartment to cooling of the refrigerator compartment, control means is provided for operating the compressor for a predetermined time at a certain operating frequency set for each outside air temperature detected by the outside air temperature detecting means. And refrigerator. 12. Immediately before switching from cooling of the freezing room to cooling of the refrigerator compartment, the first and the second predetermined times and operating frequencies set by the outside air temperature detected by the outside air temperature detecting means are used.
A refrigerator comprising control means for operating the compressor with both the second on-off valves closed. 13. The compressor is a variable capacity compressor,
Immediately before switching from cooling of the freezing room to cooling of the refrigerator compartment, and immediately before cooling the refrigerator compartment at the time of starting the compressor,
A refrigerator comprising: control means for operating the compressor at an operation frequency at which the speed is lowest when both the first and second on-off valves are closed for a predetermined time. 14. The refrigerator according to claim 1, wherein a flammable natural refrigerant (such as isobutane or propane) is used as a refrigerant in the cooling cycle.