WO2013128845A1

WO2013128845A1 - Refrigerator

Info

Publication number: WO2013128845A1
Application number: PCT/JP2013/000926
Authority: WO
Inventors: 境　寿和
Original assignee: パナソニック株式会社
Priority date: 2012-02-29
Filing date: 2013-02-20
Publication date: 2013-09-06
Also published as: JP6074596B2; JP2013210180A; CN104160224A

Abstract

A refrigerator comprises a refrigeration cycle having at least a compressor (19), an evaporator (20), and a condenser (21); and the refrigerator has the condenser (21) as the main component of a forced air cooling system, a flow channel switching valve (40) connected to the downstream side of the main component condenser (21), and a plurality of anti-moisture pipes (44, 41) downstream of the flow channel switching valve (40). When the refrigeration cycle is operating under normal conditions, refrigerant is channeled alternately to the plurality of anti-moisture pipes (44, 41), and when the refrigeration cycle is operating under overload conditions, refrigerant is channeled to the plurality of anti-moisture pipes (44, 41) in parallel.

Description

refrigerator

The present invention has a damper that has a damper that blocks cold air in a freezing room and a refrigerating room, respectively, and uses a single evaporator to individually cool the freezing room and the refrigerating room, thereby improving the efficiency of the refrigerating cycle. It is about.

From the viewpoint of energy saving, there are refrigerators for homes that have improved the efficiency of the refrigeration cycle by cooling each of the freezer compartment and the refrigerator compartment using a single evaporator. This enhances the efficiency of the refrigeration cycle by cooling the refrigerator compartment having a relatively high air temperature at an evaporation temperature higher than that of the freezer compartment.

Furthermore, it has been proposed to cool the refrigerating chamber using a cooler of the evaporator, which is at a low temperature while the compressor is stopped, using dampers provided in each of the freezing chamber and the refrigerating chamber to block cold air (for example, , See Patent Document 1). This saves energy by reducing the operating rate of the refrigeration cycle necessary for cooling the refrigerator compartment while reducing the heater power during defrosting by reusing the heat of sublimation or melting of frost adhering to the evaporator. It aims to make it easier.

Hereinafter, a conventional refrigerator will be described with reference to the drawings.

5 is a longitudinal sectional view of a conventional refrigerator, FIG. 6 is a configuration diagram of a refrigeration cycle of the conventional refrigerator, FIG. 7 is a schematic diagram of the front of the conventional refrigerator, and FIG. 8 is a state transition and switching in the cooling control of the conventional refrigerator. It is a figure showing conditions.

5 to 7, the refrigerator 11 is disposed on the housing 12, the door 13, the legs 14 that support the housing 12, the lower machine room 15 provided in the lower portion of the housing 12, and the upper portion of the housing 12. The refrigerating room 17 and the freezing room 18 disposed in the lower part of the housing 12 are provided. The refrigerator 11 is housed in the lower machine room 15 as a component constituting the refrigeration cycle, the compressor 56 housed in the lower machine room 15, the evaporator 20 housed on the back side of the freezer room 18, and the lower machine room 15. The main condenser 21 is provided. The refrigerator 11 includes a partition wall 22 that partitions the lower machine room 15, a fan 23 that is attached to the partition wall 22 to air-cool the main condenser 21, an evaporating dish 57 installed on the upper part of the compressor 56, and the lower machine room 15. The bottom plate 25 is provided.

The refrigerator 11 includes a plurality of air intakes 26 provided on the bottom plate 25, an exhaust port 27 provided on the back side of the lower machine room 15, an exhaust port 27 of the lower machine room 15, and an upper part of the housing 12. The communication air passage 28 is connected. Here, the lower machine chamber 15 is divided into two chambers by the partition wall 22, and the main condenser 21 is housed on the windward side of the fan 23, and the compressor 56 and the evaporating dish 57 are housed on the leeward side.

In addition, the refrigerator 11 is located on the downstream side of the main condenser 21 as a component constituting the refrigeration cycle, and a dew-proof pipe 37 that is thermally coupled to the outer surface of the housing 12 around the opening of the freezer compartment 18; It has a dryer 38 for drying the circulating refrigerant, and a throttle 39 for connecting the dryer 38 and the evaporator 20 and depressurizing the circulating refrigerant.

The refrigerator 11 also includes an evaporator fan 50 that supplies cold air generated in the evaporator 20 to the refrigerator compartment 17 and the freezer compartment 18, a freezer compartment damper 51 that blocks the cold air supplied to the freezer compartment 18, and the refrigerator compartment 17. A cold room damper 52 for shutting off cool air supplied to the vehicle is provided. Further, the refrigerator 11 includes a duct 53 that supplies cold air to the refrigerator compartment 17, an FCC temperature sensor 54 that detects the temperature of the freezer compartment 18, a PCC temperature sensor 55 that detects the temperature of the refrigerator compartment 17, and the evaporator 20. A DEF temperature sensor 58 for detecting temperature is included.

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

In FIG. 8, conditions M1 to M11 indicate mode switching in the conventional cooling control of the refrigerator.

Starting from a cooling stop state in which the fan 23, the compressor 56, and the evaporator fan 50 are all stopped (hereinafter, this operation is referred to as “OFF mode”). In the “OFF mode”, the temperature detected by the FCC temperature sensor 54 rises to a predetermined FCC_ON temperature, or the temperature detected by the PCC temperature sensor 55 rises to a predetermined PCC_ON temperature (that is, the condition M1 is set). Satisfied). Then, the freezer compartment damper 51 is closed, the refrigerator compartment damper 52 is opened, and the compressor 56, the fan 23, and the evaporator fan 50 are driven (hereinafter, this operation is referred to as “PC cooling mode”).

In the “PC cooling mode”, when the fan 23 is driven, the main condenser 21 side of the lower machine chamber 15 partitioned by the partition wall 22 has a negative pressure, and external air is sucked from the plurality of intake ports 26, The evaporating dish 57 side becomes positive pressure, and the air in the lower machine chamber 15 is discharged to the outside from the plurality of discharge ports 27.

On the other hand, the refrigerant discharged from the compressor 56 is condensed while leaving a part of the gas while exchanging heat with the outside air in the main condenser 21 and then supplied to the dewproof pipe 37. The refrigerant that has passed through the dew-proof pipe 37 radiates heat through the housing 12 and condenses while warming the opening of the freezer compartment 18. The liquid refrigerant that has passed through the dew-proof pipe 37 is dehydrated by the dryer 38, depressurized by the throttle 39, and is evaporated by the evaporator 20, while exchanging heat with the air in the refrigerator compartment 17 and cooling the refrigerator compartment 17. Then, it returns to the compressor 56 as a gaseous refrigerant.

During the “PC cooling mode”, the temperature detected by the FCC temperature sensor 54 decreases to a predetermined FCC_OFF temperature, and the temperature detected by the PCC temperature sensor 55 decreases to a predetermined PCC_OFF temperature (that is, the condition M2 ), Transition to the “OFF mode”.

Further, during the “PC cooling mode”, the temperature detected by the FCC temperature sensor 54 is higher than a predetermined FCC_OFF temperature, and the temperature detected by the PCC temperature sensor 55 is lowered to the predetermined PCC_OFF temperature (ie, And satisfies the condition M5). Then, the freezer compartment damper 51 is opened, the refrigerator compartment damper 52 is closed, and the compressor 56, the fan 23, and the evaporator fan 50 are driven. Thereafter, by operating the refrigeration cycle in the same manner as PC cooling, the freezer compartment 18 is heat-exchanged with the inside air of the freezer compartment 18 and the evaporator 20 to cool the freezer compartment 18 (this operation is hereinafter referred to as “FC cooling mode”). .

During the “FC cooling mode”, the temperature detected by the FCC temperature sensor 54 falls to a predetermined FCC_OFF temperature, and the temperature detected by the PCC temperature sensor 55 is equal to or higher than the predetermined PCC_ON temperature (that is, the condition M6 is satisfied). If satisfied, the PC cooling mode is entered.

Further, during the “FC cooling mode”, the temperature detected by the FCC temperature sensor 54 decreases to a predetermined FCC_OFF temperature, and the temperature detected by the PCC temperature sensor 55 is lower than the predetermined PCC_ON temperature (ie, , The condition M4 is satisfied), and a transition is made to the OFF mode.

Next, a cooling operation using frost attached to the evaporator 20 will be described.

The defrost heater (not shown) installed in the vicinity of the evaporator 20 is energized, the compressor 56 is stopped, the freezer damper 51 is closed, the refrigerator compartment damper 52 is opened, and the evaporator fan 50 is driven. (Hereinafter, this operation is referred to as “defrost mode”), the frost adhering to the evaporator 20 is melted and removed, and the refrigerator compartment 17 is cooled using the sublimation heat or heat of fusion of the frost being removed.

Further, without supplying power to a defrosting heater (not shown) installed in the vicinity of the evaporator 20, the compressor 56 is stopped, the freezer compartment damper 51 is closed, the refrigerator compartment damper 52 is opened, and the evaporator fan 50 is opened. (Hereinafter, this operation is referred to as “off-cycle cooling mode”), and the refrigerator 20 uses the low-temperature sensible heat of the frost and the sublimation heat or melting heat of the frost adhering to the evaporator 20. 17 is cooled. At this time, the frost attached to the evaporator 20 is not completely thawed and removed. However, by reusing the frost attached to the evaporator 20, the power of the heater (not shown) in the “defrost mode” is used. Thus, the refrigerator compartment 17 can be cooled.

In order to cool the freezer compartment 18 to a temperature lower than usual when the power is turned on or when a predetermined time Tx2 has elapsed from the end of the previous defrost (that is, the condition M7 is satisfied) during the “FC cooling mode”. FC cooling is continued for a predetermined time (hereinafter, this operation is referred to as “precool mode”). Next, when the predetermined time Tx3 has elapsed from the start of the precool (that is, the condition M8 is satisfied), the operation shifts to the defrost operation. Then, during defrosting, the temperature detected by the DEF temperature sensor 58 attached to the evaporator 20 indicates a temperature higher than a predetermined value of DEF_OFF temperature, or a predetermined time Tx4 has elapsed from the start of defrosting (that is, the condition M9 is satisfied). Satisfied), transition to “off-cycle cooling mode”.

Also, during the “OFF mode”, when a predetermined time Tm has elapsed from the start of OFF (that is, the condition M10 is satisfied), the state transits to the “off cycle cooling mode”.

In the “off cycle cooling mode”, when the predetermined time Td elapses from the start of the off cycle cooling (that is, the condition M11 is satisfied), the state transits to the “OFF mode”.

Here, the cooling operation under an overload condition will be described.

In the conventional refrigerator, since cooling control is performed by switching between PC cooling for cooling the refrigerator compartment 17 alone and FC cooling for cooling the freezer compartment 18 alone, high-temperature foods or the like are stored in the refrigerator compartment 17 or the refrigerator compartment 18. When an excessive load that is thrown in is generated, there is a concern that either the refrigerator compartment 17 or the freezer compartment 18 is not cooled for a long time.

Therefore, as described in the condition M5, when the temperature detected by the FCC temperature sensor 54 exceeds the predetermined FCC_ON temperature during the “PC cooling mode”, or as described in the condition M6, “FC A case will be described in which the temperature detected by the PCC temperature sensor 55 exceeds the PCC_ON temperature of a predetermined value during the “cooling mode”. In this case, until the temperature detected by the PCC temperature sensor 55 reaches a predetermined PCC_OFF temperature, or until the temperature detected by the FCC temperature sensor 54 reaches the predetermined FCC_OFF temperature, the PC for a predetermined time Txr. Cooling and FC cooling for a predetermined time Txf are alternately repeated (hereinafter, this operation is referred to as “alternate cooling”). As a result, it is possible to avoid a state in which one of the refrigerator compartment 17 and the freezer compartment 18 is not cooled for a long time.

By the operation described above, the efficiency of the refrigeration cycle can be increased by keeping the temperature of the evaporator 20 in the “PC cooling mode” higher than that in the “FC cooling mode”. Furthermore, by reusing the melting latent heat of frost adhering to the evaporator 20 in the “off cycle cooling mode”, the refrigeration necessary for cooling the refrigerator compartment 17 while reducing heater power (not shown) at the time of defrosting. Energy saving can be achieved by reducing the cycle operating rate.

However, in the conventional refrigerator configuration, since the refrigerant always flows through the dew prevention pipe 37 regardless of the installation environment and the operating state of the refrigerator, the refrigerator is caused by the heat load entering the freezer compartment 18 from the dew prevention pipe 37. This causes an increase in power consumption.

Also, the dew-proof pipe 37 composed of long thin pipes has a large pressure loss, which causes a rise in the condensation temperature especially in an overload condition in which the amount of refrigerant circulation increases, leading to an increase in power consumption of the refrigerator.

Therefore, it has been a problem to suppress the pressure loss and heat load caused by the dew-proof pipe depending on the installation environment and operation state of the refrigerator.

JP-A-9-236369

The refrigerator of the present invention has a plurality of dew prevention pipes connected in parallel via a flow path switching valve on the downstream side of the main condenser.

This makes it possible to suppress a pressure loss caused by the dew prevention pipe by using a plurality of dew prevention pipes in parallel at the time of an overload particularly when the refrigerant circulation amount is large. Here, the time of overload is assumed, for example, when the door is frequently opened and closed in summer when the temperature and humidity of the outside air are relatively high, or when food with a high temperature is stored. In such a case, the operating rate of the refrigeration cycle increases and the amount of refrigerant circulation increases, and it is necessary to prevent condensation around the refrigerator casing in which the dew-proof pipe is provided. At this time, the pressure loss resulting from the dew-proof pipe can be suppressed by simultaneously using the dew-proof pipe in parallel to reduce the amount of refrigerant circulation per bottle.

FIG. 1 is a longitudinal sectional view of a refrigerator in the first embodiment of the present invention. FIG. 2 is a cycle configuration diagram of the refrigerator in the first embodiment of the present invention. FIG. 3 is a schematic view of the back surface of the refrigerator in the first embodiment of the present invention. FIG. 4 is a diagram showing state transitions and switching conditions in cooling control of the refrigerator in the first embodiment of the present invention. FIG. 5 is a longitudinal sectional view of a conventional refrigerator. FIG. 6 is a cycle configuration diagram of a conventional refrigerator. FIG. 7 is a schematic front view of a conventional refrigerator. FIG. 8 is a diagram showing state transition and switching conditions in the conventional refrigerator cooling control.

Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the same components as those in the conventional example are denoted by the same reference numerals, and detailed description thereof will be omitted. The present invention is not limited to the embodiments.

(First embodiment)
1 is a longitudinal sectional view of a refrigerator according to the first embodiment of the present invention, FIG. 2 is a cycle configuration diagram of the refrigerator according to the first embodiment of the present invention, and FIG. 3 is a first embodiment of the present invention. FIG. 4 is a diagram showing the state transition and the switching conditions in the cooling control of the refrigerator in the first embodiment of the present invention.

1 to 3, the refrigerator 11 is provided with a housing 12, a door 13, legs 14 that support the housing 12, a lower machine room 15 provided at the lower portion of the housing 12, and an upper portion of the housing 12. The upper machine room 16 is provided, the refrigerator room 17 is disposed at the upper part of the housing 12, and the freezer room 18 is disposed at the lower part of the housing 12. The refrigerator 11 is housed in a compressor 19 housed in the upper machine room 16, an evaporator 20 housed on the back side of the freezer room 18, and a lower machine room 15 as components constituting the refrigeration cycle. The main condenser 21 is provided. The refrigerator 11 includes a partition wall 22 that partitions the lower machine room 15, a fan 23 that is attached to the partition wall 22 to air-cool the main condenser 21, an evaporating dish 24 installed on the leeward side of the partition wall 22, and the lower machine room 15. The bottom plate 25 is provided.

Here, the compressor 19 is a variable speed compressor and uses six stages of rotation speed selected from 20 to 80 rps. This is because the refrigerating capacity is adjusted by switching the rotational speed of the compressor 19 to six stages from low speed to high speed while avoiding resonance of piping and the like. The compressor 19 operates at a low speed at the time of startup, and increases as the operation time for cooling the refrigerator compartment 17 or the freezer compartment 18 becomes longer. This is because the most efficient low speed is mainly used, and an appropriate relatively high rotational speed is used against an increase in load of the refrigerator compartment 17 or the freezer compartment 18 due to high outside air temperature, door opening / closing, or the like. . At this time, the rotation speed of the compressor 19 is controlled independently of the cooling operation mode of the refrigerator 11, but the rotation speed at the start of the “PC cooling mode” with a high evaporation temperature and a relatively large refrigerating capacity is set to “FC cooling”. It may be set lower than “mode”. Further, the refrigeration capacity may be adjusted while decelerating the compressor 19 as the temperature of the refrigerator compartment 17 or the freezer compartment 18 decreases.

The refrigerator 11 connects the plurality of air intakes 26 provided on the bottom plate 25, the exhaust port 27 provided on the back side of the lower machine room 15, and the exhaust port 27 of the lower machine room 15 and the upper machine room 16. A communication air passage 28 is provided. Here, the lower machine chamber 15 is divided into two chambers by a partition wall 22, and a main condenser 21 is housed on the windward side of the fan 23 and an evaporating dish 24 is housed on the leeward side.

The refrigerator 11 is a first dew-proof pipe that is located on the downstream side of the main condenser 21 as a component constituting the refrigeration cycle and is thermally coupled to the outer surface of the housing 12 around the opening of the freezer compartment 18. 44, a dryer 38 for drying the circulating refrigerant, and a throttle 39 for connecting the dryer 38 and the evaporator 20 to depressurize the circulating refrigerant. .

Here, in order to branch the refrigerant flow path of the first dew-proof pipe 44, a flow path switching valve 40, a second dew-proof pipe 41, and a junction 42 are provided. The first dew proof pipe 44 and the second dew proof pipe 41 connect the flow path switching valve 40 and the junction 42 in parallel, and the flow path switching valve 40 includes the first dew proof pipe 44 and the second dew proof pipe 44. It is possible to control the opening and closing of the single refrigerant flow of each of the dew prevention pipes 41. Further, the second dew-proof pipe 41 has substantially the same internal volume and heat-dissipation capacity as the first dew-proof pipe 44 and radiates heat in contact with the back surface of the housing 12, and overlaps with the vacuum heat insulating material 43. By doing so, heat transfer to the inside of the housing 12 is suppressed.

In addition, the refrigerator 11 includes an evaporator fan 30 that supplies cold air generated in the evaporator 20 to the refrigerator compartment 17 and the freezer compartment 18, a freezer damper 31 that blocks cold air supplied to the freezer compartment 18, and the refrigerator compartment 17. The refrigerator has a refrigerator compartment damper 32 for shutting off the cold air supplied thereto. Further, the refrigerator 11 includes a duct 33 that supplies cold air to the refrigerator compartment 17, an FCC temperature sensor 34 that detects the temperature of the freezer compartment 18, a PCC temperature sensor 35 that detects the temperature of the refrigerator compartment 17, and the evaporator 20. It has a DEF temperature sensor 36 for detecting temperature. Here, the duct 33 is formed along a wall surface where the refrigerator compartment 17 and the upper machine room 16 are adjacent to each other, and a part of the cold air passing through the duct 33 is discharged from the vicinity of the center of the refrigerator compartment, and most of the cold air is in the upper machine. After passing through the wall 16 while cooling the adjacent wall surface, it is discharged from the upper part of the refrigerator compartment 17.

The operation of the refrigerator according to the first embodiment of the present invention configured as described above will be described below.

In FIG. 4, conditions L1 to L15 indicate mode switching in the cooling control of the refrigerator in the first embodiment of the present invention. Here, detailed description of the same cooling operation mode and mode switching condition as those of the conventional refrigerator is omitted.

First, the “off-cycle cooling mode” will be described.

When the condition L10 (that is, the condition M10) is satisfied during the “OFF mode”, the state transits to the “off cycle cooling mode”.

Then, during the “off cycle cooling mode”, the condition L1 (that is, the condition M1) is satisfied, or the temperature detected by the DEF temperature sensor 36 rises to a predetermined OSR_OFF temperature (that is, the condition L11 is satisfied). ) And transition to the “OFF mode”.

Thereby, using the DEF temperature sensor 36 installed in the evaporator 20, the time of the “off cycle cooling mode” can be adjusted appropriately. Since the conventional refrigerator always performs off-cycle cooling for a certain time Td, there is a concern that the temperature of the evaporator 20 rises more than necessary and heat is transferred to the adjacent freezer compartment 18 to increase the heat load. The OSR_OFF temperature, which is the reference temperature for ending the “off cycle cooling mode”, is desirably set to about −15 to −5 ° C. If it is less than −15 ° C., the effect of off-cycle cooling cannot be obtained sufficiently, and if it exceeds −5 ° C., the heat load of the freezer compartment 18 may increase.

Next, the cooling operation under normal conditions will be described.

During the “PC cooling mode”, the temperature detected by the FCC temperature sensor 34 is higher than a predetermined FCC_OFF temperature, and the temperature detected by the PCC temperature sensor 35 falls to the predetermined PCC_OFF temperature (that is, the condition) When L5 is satisfied), the mode is changed to the FC cooling mode. In addition, as described in the condition L5, the difference between the temperature detected by the FCC temperature sensor 34 and the FCC_OFF temperature of the predetermined value is the temperature detected by the PCC temperature sensor 35 after the predetermined time Tx1 has elapsed during the PC cooling mode. Transition to the “FC cooling mode”.

In the “FC cooling mode”, the refrigerant discharged from the compressor 19 is condensed while leaving a part of the gas while exchanging heat with the outside air in the main condenser 21, and then the first refrigerant via the flow path switching valve 40. The dew-proof pipe 44 or the second dew-proof pipe 41 is supplied. At this time, the flow path switching valve 40 is controlled to supply the refrigerant alternately to either the first dew-proof pipe 44 or the second dew-proof pipe 41. As a result, the amount of heat load that enters the freezer compartment 18 from the first dewproof pipe 44 through the opening of the freezer compartment 18 can be reduced.

Thereafter, the liquid refrigerant that has passed through the junction 42 is subjected to moisture removal by the dryer 38 as in the prior art, reduced in pressure by the throttle 39 and heat-exchanged with the air in the refrigerator compartment 17 while evaporating in the evaporator 20. While cooling 17, the refrigerant is returned to the compressor 19 as a gaseous refrigerant.

In addition, since the 1st dew-proof pipe 44 and the 2nd dew-proof pipe 41 have substantially the same internal volume and heat dissipation capability, the amount of liquid refrigerant held in the unused state and the amount of heat released in the used state are the same. Thus, there is no significant change in the cooling state accompanying switching, and cooling can be performed efficiently.

During the “FC cooling mode”, the temperature detected by the FCC temperature sensor 34 falls to a predetermined FCC_OFF temperature, and the temperature detected by the PCC temperature sensor 35 is equal to or higher than the predetermined PCC_ON temperature (that is, the condition L6 is satisfied). Satisfied), transition to “PC cooling mode”. In addition, as described in the condition L6, the difference between the temperature detected by the FCC temperature sensor 34 and the FCC_OFF temperature of the predetermined value is detected by the PCC temperature sensor 35 after the predetermined time Tx1 has elapsed during the “FC cooling mode”. When the temperature becomes equal to or less than the difference between the temperature to be measured and the PCC_OFF temperature of a predetermined value, the mode is changed to “PC cooling mode”.

In the “PC cooling mode”, the refrigerant discharged from the compressor 19 is condensed while leaving a part of the gas while exchanging heat with the outside air in the main condenser 21, and then the first refrigerant via the flow path switching valve 40. The dew-proof pipe 44 or the second dew-proof pipe 41 is supplied. At this time, the flow path switching valve 40 is controlled to supply the refrigerant alternately to either the first dew-proof pipe 44 or the second dew-proof pipe 41. As a result, the amount of heat load that enters the freezer compartment 18 from the first dewproof pipe 44 through the opening of the freezer compartment 18 can be reduced.

In addition, since the 1st dew-proof pipe 44 and the 2nd dew-proof pipe 41 have substantially the same internal volume and heat dissipation capability, the amount of liquid refrigerant held in the unused state and the amount of heat released in the used state are the same. Thus, there is no significant change in the cooling state accompanying switching, and cooling can be performed efficiently. In the “PC cooling mode”, the cold air does not flow into the freezer compartment 18 and the temperature in the freezer compartment 18 is relatively higher than in the “FC cooling mode”. The ratio may be kept lower than in the “FC cooling mode”.

Next, the cooling operation under overload conditions will be described.

Under the overload conditions, such as when the power is turned on, where both the refrigerator compartment 17 and the freezer compartment 18 are hot due to the control of the normal conditions described above, the “PC cooling mode” and the “FC cooling mode” are alternated every predetermined time Tx1. In addition, it is possible to preferentially cool the one having a larger divergence from the OFF temperature, which is a guide for ending the cooling. As a result, the cooling operation time can be distributed more flexibly than the time-fixed alternating cooling performed in the conventional refrigerator.

However, even if alternate cooling is performed with a degree of freedom in the cooling operation time, the freezer compartment 18 is intermittently cooled, and there is a concern that the upper limit of the storage temperature of frozen food such as ice cream may be exceeded. Therefore, an operation of cooling the refrigerator compartment 17 and the freezer compartment 18 at the same time (hereinafter, this operation is referred to as “simultaneous cooling mode”) is added only under an overload condition.

In the “simultaneous cooling mode”, the freezer damper 31 is opened and the refrigerator compartment damper 32 is opened to drive the compressor 19, the fan 23, and the evaporator fan 30. In the “simultaneous cooling mode”, when the fan 23 is driven, the main condenser 21 side of the lower machine chamber 15 partitioned by the partition wall 22 has a negative pressure, and external air is sucked from the plurality of intake ports 26, The evaporating dish 57 side becomes positive pressure, and the air in the lower machine chamber 15 is discharged to the outside from the plurality of discharge ports 27.

On the other hand, the refrigerant discharged from the compressor 19 is condensed while leaving a part of the gas while exchanging heat with the outside air in the main condenser 21, and then the first dew-proof pipe 44 or the like via the flow path switching valve 40. Supplied to the second dewproof pipe 41. At this time, the flow path switching valve 40 is controlled to supply the refrigerant to both the first dew-proof pipe 44 and the second dew-proof pipe 41 simultaneously. As a result, the pressure loss caused by the first dew-proof pipe 44 and the second dew-proof pipe 41 can be suppressed by reducing the refrigerant circulation amount per bottle.

Thereafter, the liquid refrigerant that has passed through the confluence 42 is dehydrated by the dryer 38, depressurized by the throttle 39 and evaporated by the evaporator 20, and exchanges heat with the air in the refrigerator compartment 17 and the freezer compartment 18 to store the refrigerator. While cooling 17 and the freezer compartment 18, the refrigerant is returned to the compressor 19 as a gaseous refrigerant.

At this time, the evaporator fan 30 is rotated at a high speed to secure an air volume necessary for cooling the refrigerator compartment 17 and the freezer compartment 18 in parallel. As a result, as compared with the “FC cooling mode”, air that has a high wind speed at a high temperature flows into the evaporator 20 and the temperature of the blown air from the evaporator 20 tends to rise. It is desirable to operate the machine 19 to ensure proper refrigeration capacity. When the compressor 19 is operated at a low speed in the “simultaneous cooling mode”, there is a concern that the temperature of the air blown from the evaporator 20 increases and the freezer compartment 18 cannot be cooled to a low temperature.

Therefore, when the rotation speed of the compressor 19 is equal to or higher than the predetermined rotation speed during the “PC cooling mode” (that is, the condition L12 is satisfied), the mode is changed to the “simultaneous cooling mode” and the “simultaneous cooling mode” is being performed. On the other hand, when the rotation speed of the compressor 19 is less than the predetermined rotation speed (that is, the condition L13 is satisfied), the state transits to the “PC cooling mode”. The mode switching between the conditions L12 and L13 is performed with priority over other state transitions. This is because the rotation speed of the compressor 19 is increased to a predetermined rotation speed or more, and it is detected that the refrigerator 11 is in an overload condition and transitions to the “simultaneous cooling mode”. This is to avoid that the temperature of the blown air from the evaporator 20 rises and the freezer compartment 18 cannot be cooled to a low temperature when the rotational speed is less than the predetermined rotational speed.

Further, during the “simultaneous cooling mode”, the temperature detected by the PCC temperature sensor 35 falls below a predetermined value of the PCC_OFF temperature, or the temperature detected by the FCC temperature sensor 34 exceeds the FCC_ON temperature after a predetermined time Tx5 has elapsed. Transition to the “FC cooling mode” when the FCC_LIM temperature is higher than the predetermined value (that is, the condition L14 is satisfied). This is to continue the simultaneous cooling mode up to the upper temperature limit at which the freezer compartment 18 is allowed in order to suppress the temperature rise of the refrigerator compartment 17 that is not cooled during the “FC cooling mode”. Therefore, it is desirable that the FCC_LIM temperature detected by the FCC temperature sensor 34 is a predetermined value corresponding to weak cooling that is 2 to 5 ° C. higher than the FCC_ON temperature that is the upper limit temperature during normal cooling.

In the present embodiment, the condition L12 for transitioning to the “simultaneous cooling mode” corresponding to the overload condition is defined by the number of revolutions of the compressor 19. However, when the power is turned on at high outside air temperature and the door is frequently opened and closed. May be detected and a transition to the “simultaneous cooling mode” may be made. If it is clear that the refrigerator 19 is in an overload condition without increasing the speed of the compressor 19, it is possible to shift to the “simultaneous cooling mode” earlier. In this case, the condition L13 may be changed so that the simultaneous cooling mode is canceled by detecting that the temperature of the refrigerator compartment 17 or the freezer compartment 18 is lowered to some extent. As a result, like the present embodiment, the most efficient PC cooling mode can be used for a longer time.

Next, defrosting when the evaporator 20 is frosted during the “simultaneous cooling mode” will be described.

When the temperature detected by the FCC temperature sensor 34 is lower than the FCC_LIM temperature during the “simultaneous cooling mode”, the opening degree of the freezer damper 31 is lowered. This prioritizes cooling of the refrigerating room 17 when the freezing room 18 reaches a weak cooling level, and therefore suppresses the air volume distribution to the freezing room 18. Then, after the elapse of a predetermined time Tx6 from the start of the “simultaneous cooling mode”, when the temperature detected by the PCC temperature sensor 35 exceeds the PCC_OFF temperature (that is, the condition L15 is satisfied), the mode is changed to the defrost mode.

When the evaporator 20 is frosted during the “simultaneous cooling mode” and the refrigerating chamber 17 tends to be slowly cooled, normal defrosting performed every predetermined time Tx2 is carried out earlier. The cooling capacity of the refrigerator compartment 17 can be recovered early by shortening the defrosting interval of the container 20. In the “simultaneous cooling mode”, the evaporator fan 30 is rotated at a high speed to secure the amount of air sent in parallel to both the refrigerator compartment 17 and the freezer compartment 18, but a large amount of frost is generated in the evaporator 20. In such a case, a sufficient air volume cannot be secured. At this time, compared with the freezer compartment 18 formed just before the evaporator 20, the air volume of the refrigerator compartment 17 with the comparatively long path | route which ventilates from the evaporator 20 falls significantly. Therefore, in order to give priority to the cooling of the refrigerator compartment 17 when the freezer compartment 18 reaches a weak cooling level, the air volume distribution amount to the refrigerator compartment 18 is suppressed, and the refrigerator compartment 17 is still cooled after the predetermined time Tx6 has elapsed. When it is determined as insufficient, the cooling capacity of the refrigerator compartment 17 can be recovered early by shortening the defrosting interval of the evaporator 20.

As described above, the refrigerator of the present invention flows in the downstream side of the main condenser 21 in the refrigerator having the “simultaneous cooling mode” only in the overload condition in addition to the “FC cooling mode” and the “PC cooling mode”. The first dew-proof pipe 44 and the second dew-proof pipe 41 are connected in parallel via the path switching valve 40 and arbitrarily selected. Thus, during normal operation, the first dew proof pipe 44 and the second dew proof pipe 41 are switched alternately and used to suppress the thermal load caused by the first dew proof pipe 44, and During an overload operation, the first dew proof pipe 44 and the second dew proof pipe 41 can be used simultaneously in parallel to reduce the refrigerant circulation rate and suppress the pressure loss.

In the refrigerator in the present embodiment, the operation of fully closing the flow path switching valve 40 is not performed, but the flow path switching valve 40 is fully closed during the “OFF mode” and the liquid in the main condenser 21 is If the refrigerant is not allowed to flow downstream, the amount of the high-temperature liquid refrigerant flowing into the evaporator 20 during the “OFF mode” can be suppressed, and the heat load of the refrigerator can be reduced.

As described above, the present invention includes a refrigeration cycle having at least a compressor, an evaporator, and a condenser, and the condenser is a forced air-cooled main condenser and a flow path switching valve connected to the downstream side of the main condenser. And a sub-condenser connected to the downstream side of the flow path switching valve, and the sub-condenser includes a plurality of dew-proof pipes connected in parallel. When the refrigeration cycle is operated under normal conditions, the refrigerant is alternately supplied to the plurality of dew prevention pipes, and when operated under an overload condition, the refrigerant is supplied in parallel to the plurality of dew prevention pipes.

As a result, the heat load caused by the dew proof pipe is normally suppressed, and the pressure loss caused by the dew proof pipe is simultaneously reduced by using a plurality of dew proof pipes in parallel at the time of overload with a large amount of refrigerant circulation. Can do. Here, the time of overload is assumed, for example, when the door is frequently opened and closed in summer when the temperature and humidity of the outside air are relatively high, or when food with a high temperature is stored. In such a case, the operating rate of the refrigeration cycle increases and the amount of refrigerant circulation increases, and it is necessary to prevent condensation around the refrigerator casing in which the dew-proof pipe is provided. At this time, the pressure loss resulting from the dew-proof pipe can be suppressed by simultaneously using the dew-proof pipe in parallel to reduce the amount of refrigerant circulation per bottle.

In addition, the present invention includes a refrigerator compartment and a freezer compartment, and allows the refrigerant to flow in parallel to the plurality of dew-proof pipes when the refrigerator compartment and the freezer compartment are both higher than a predetermined temperature.

This makes it possible to perform energy saving by performing the operation according to each condition by dividing the case into operation under normal conditions and operation under overload conditions. Furthermore, after accurately grasping the overload when the refrigerant circulation amount is large, it is possible to suppress the pressure loss caused by the dew prevention pipe by using multiple dew prevention pipes in parallel at the same time. Temperature rise can be suppressed.

The present invention also includes a refrigerator compartment, a freezer compartment, a refrigeration cycle, an evaporator that is a component of the refrigeration cycle, an evaporator fan that supplies cold air generated in the evaporator to the refrigerator compartment and the freezer compartment, A refrigerator compartment damper for shutting off cool air supplied from the evaporator to the refrigerator compartment, and a freezer compartment damper for shutting off cool air supplied from the evaporator to the freezer compartment. Furthermore, it has the FCC temperature sensor which detects the temperature of a freezer compartment, and the PCC temperature sensor which detects the temperature of a refrigerator compartment. And, opening the freezer damper, closing the refrigerator compartment damper, supplying the cool air generated in the evaporator while operating the refrigeration cycle to cool the freezer compartment, and closing the freezer damper, It has a PC cooling mode in which the cold room damper is opened and cold air generated in the evaporator is supplied while the refrigeration cycle is operated to cool the cold room. In addition, the freezing room damper is opened, the freezing room damper is opened, and the freezing room damper is operated to supply the cold air generated in the evaporator while operating the refrigerating cycle to simultaneously cool the freezing room and the refrigerating room, and the freezing room damper Is closed, the refrigerator compartment damper is opened, and the evaporator fan is operated while stopping the refrigeration cycle, thereby having an off-cycle cooling mode for exchanging heat between the evaporator and the air in the refrigerator compartment. Under normal conditions, the cooling is performed by combining the FC cooling mode, the PC cooling mode, and the off-cycle cooling mode, and under the overload condition, the simultaneous cooling mode and the FC cooling mode are combined.

As a result, the PC cooling mode with high efficiency can be maintained as much as possible under normal conditions, and the cooling amount of the freezer compartment and the refrigerator compartment can be automatically adjusted appropriately while continuing to cool the freezer compartment under overload conditions. Moreover, the temperature rise of a refrigerator compartment and a freezer compartment can be suppressed.

In the present invention, the compressor is a variable speed compressor, and during normal operation, the compressor is operated at less than a predetermined number of rotations while cooling by combining the FC cooling mode, the PC cooling mode, and the off-cycle cooling mode. Under the load condition, the compressor is cooled at a predetermined rotational speed or more by combining the simultaneous cooling mode and the FC cooling mode.

This makes it possible to suppress an increase in the temperature of the evaporator in the simultaneous cooling mode and to suppress a cooling capacity shortage in the freezer compartment.

Further, the present invention includes an upper machine room and a lower machine room, and a compressor is arranged in the upper machine room and a flow path switching valve is arranged in the lower machine room.

This can reduce the noise of the refrigerator by suppressing the resonance between the connecting pipe of the flow path switching valve and the compressor.

As described above, the refrigerator according to the present invention has a plurality of dew-proof pipes connected in parallel to the downstream side of the main condenser via the flow path switching valve, so that the dew-proof pipes can be used depending on the installation environment and operation state of the refrigerator. Since the resulting pressure loss and thermal load can be adjusted arbitrarily, it can be applied to other refrigeration application products such as commercial refrigerators.

DESCRIPTION OF SYMBOLS 11 Refrigerator 12 Case 15 Lower machine room 16 Upper machine room 19 Compressor 20 Evaporator 24 Evaporator 30 Evaporator fan 31 Freezer damper 32 Refrigerator damper 33 Duct 34 FCC temperature sensor 35 PCC temperature sensor 36 DEF temperature sensor 37 Prevention Dew pipe 38 Dryer 39 Restriction 40 Flow path switching valve 41 Second dew pipe (sub-condenser)
42 Junction point 43 Vacuum insulation 44 First dew-proof pipe (sub-condenser)
50 Evaporator Fan 51 Freezer Damper 52 Refrigerator Damper 53 Duct 54 FCC Temperature Sensor 55 PCC Temperature Sensor 56 Compressor 57 Evaporating Dish 58 DEF Temperature Sensor

Claims

A refrigeration cycle having at least a compressor, an evaporator, and a condenser, wherein the condenser is a forced air-cooled main condenser, a flow path switching valve connected to a downstream side of the main condenser, and the flow path switching valve A sub-condenser connected to the downstream side of the sub-condenser, and the sub-condenser includes a plurality of dew-proof pipes connected in parallel, and when the refrigeration cycle is operated under normal conditions, the plurality of dew-proof pipes In the refrigerator, the refrigerant is allowed to flow alternately, and the refrigerant is allowed to flow in parallel to the plurality of dew-proof pipes when operating under an overload condition.
2. The refrigerator according to claim 1, further comprising a refrigerator compartment and a freezer compartment, wherein the refrigerant flows in parallel to the plurality of dew-proof pipes when the refrigerator compartment and the freezer compartment are both higher than a predetermined temperature as an overload condition. .
Refrigeration room, freezing room, the refrigeration cycle, an evaporator fan that supplies cold air generated in the evaporator to the refrigerating room and the freezing room, and cold air supplied from the evaporator to the refrigerating room is shut off A refrigerating room damper, a freezing room damper for blocking cool air supplied from the evaporator to the freezing room, an FCC temperature sensor for detecting the temperature of the freezing room, and a PCC temperature sensor for detecting the temperature of the refrigerating room FC cooling mode in which the freezer compartment damper is opened, the refrigerator compartment damper is closed, and cold air generated in the evaporator is supplied while operating the refrigerating cycle to cool the freezer compartment And closing the freezer damper, opening the refrigerating chamber damper, and supplying the cool air generated by the evaporator while operating the refrigerating cycle to cool the refrigerating chamber PC cooling mode, open the freezer damper, open the refrigerator damper, supply the cool air generated by the evaporator while operating the refrigeration cycle, and cool the refrigerator and refrigerator at the same time Simultaneous cooling mode, and closing the freezer compartment damper, opening the refrigerator compartment damper, and operating the evaporator fan while stopping the refrigeration cycle, the air in the evaporator and the refrigerator compartment It has an off-cycle cooling mode for heat exchange. In normal conditions, it cools by combining FC cooling mode, PC cooling mode, and off-cycle cooling mode, and in overload conditions, it cools by combining simultaneous cooling mode and FC cooling mode. The refrigerator according to claim 1.
The compressor is a variable speed compressor, and during normal operation, the compressor is cooled at a combination of an FC cooling mode, a PC cooling mode, and an off-cycle cooling mode while operating at less than a predetermined number of revolutions. The refrigerator according to claim 3, wherein the refrigerator is cooled by combining the simultaneous cooling mode and the FC cooling mode while operating the compressor at a predetermined rotation speed or higher.
The refrigerator according to claim 1, further comprising an upper machine room and a lower machine room, wherein the compressor is disposed in the upper machine room, and the flow path switching valve is disposed in the lower machine room.