WO2019107066A1

WO2019107066A1 - Refrigerator

Info

Publication number: WO2019107066A1
Application number: PCT/JP2018/040791
Authority: WO
Inventors: 堀尾　好正; 境　寿和; 克則堀井; 文宣高見
Original assignee: パナソニックＩｐマネジメント株式会社
Priority date: 2017-11-30
Filing date: 2018-11-02
Publication date: 2019-06-06
Also published as: JP2019100585A; JP6872689B2

Abstract

The present invention has: a flow channel switching valve (40) connected to a downstream side of a main condenser (21); a dew-proofing pipe (41) connected to a downstream side of the flow channel switching valve (40); and a bypass passage (43) connected in parallel to the dew-proofing pipe (41). When an evaporator (20) is defrosted, residual refrigerant in the evaporator (20) and the dew-proofing pipe (41) is collected through an operation of closing a freezing chamber damper, by fully closing the flow channel switching valve (40) and opening a refrigeration chamber damper at the same time during the operations of a compressor (19) and an evaporator fan (30). Thereafter, the collectged high-pressure refrigerant is supplied to the evaporator (20) by stopping the compressor (19) and opening the flow channel switching valve (40) toward the bypass passage (43). After a predetermined period of time, a defrosting heater is electrically energized.

Description

refrigerator

The present invention relates to a refrigerator that reduces the output of a defrost heater.

From the viewpoint of energy saving, in a household refrigerator, a refrigerator that reduces the output of the defrosting electric heater by using energy that heats the evaporator by the high pressure refrigerant in the refrigeration cycle flowing into the evaporator due to the pressure difference. There is. In such a refrigerator, even after the compressor is stopped, the high pressure refrigerant stored inside the condenser of the refrigeration cycle is maintained near the outside air temperature. On the other hand, since the evaporator is at a low temperature of -30 ° C to -20 ° C, the amount of high pressure refrigerant flowing into the evaporator is increased due to the pressure difference, or the enthalpy of the high pressure refrigerant flowing therein is increased to Increase it. With such a configuration, in such a refrigerator, energy saving can be achieved by actively reducing the output of the defrosting electric heater.

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

FIG. 6 is a longitudinal sectional view of a conventional refrigerator. FIG. 7 is a configuration diagram of a refrigeration cycle of a conventional refrigerator. FIG. 8 is a view showing control at the time of defrosting of the conventional refrigerator.

As shown in FIGS. 6 and 7, the refrigerator 11 includes a housing 12, a door 13, a leg 14 for supporting the housing 12, a lower machine room 15 provided in the lower part of the housing 12, and the housing 12. And a freezer compartment 18 disposed at the lower part of the housing 12. Further, as components constituting the refrigeration cycle, a compressor 56 housed in the lower machine room 15, an evaporator 20 housed on the back side of the freezer room 18, and a main condenser housed in the lower machine room 15 It has 21. The refrigerator 11 includes a main condenser 21 disposed in the lower machine room 15, a partition 22 partitioning the lower machine room 15, a fan 23 attached to the partition 22 to cool the main condenser 21, and a compressor 56. An evaporation pan 57 installed at the top and a bottom plate 25 of the lower machine room 15 are provided.

Further, the refrigerator 11 has a plurality of air inlets 26 provided on the bottom plate 25, an outlet 27 provided on the back side of the lower machine room 15, an outlet 27 of the lower machine room 15, and an upper portion of the housing 12. A communicating air passage 28 is provided to connect. Here, the lower machine room 15 is divided into two rooms by the partition wall 22, and the main condenser 21 is accommodated on the windward side of the fan 23, and the compressor 56 and the evaporation plate 57 are accommodated on the windward side.

Moreover, the refrigerator 11 is a dew protection pipe 60 located downstream of the main condenser 21 and thermally coupled to the outer surface of the housing 12 around the opening of the freezing chamber 18 as a component constituting a refrigeration cycle, A dryer 137 located on the downstream side of the dewproof pipe 60 for drying the circulating refrigerant, and a throttle 45 for connecting the dryer 137 and the evaporator 20 and reducing the pressure of the circulating refrigerant are provided. Furthermore, the refrigerator 11 includes a two-way valve 61 for closing the outlet of the dew protection pipe 60, which operates when defrosting the evaporator 20, and a defrost heater (not shown) for heating the evaporator 20. There is.

Further, the refrigerator 11 includes an evaporator fan 50 for supplying cold air generated by the evaporator 20 to the refrigerator compartment 17 and the freezer compartment 18, a freezer compartment damper 51 for shutting off the cold air supplied to the freezer compartment 18, and a refrigerator compartment 17 And a duct 53 for supplying cold air to the cold storage room 17. Furthermore, the refrigerator 11 includes an FCC temperature sensor 54 that detects the temperature of the freezing chamber 18, a PCC temperature sensor 55 that detects the temperature of the refrigerating chamber 17, and a DEF temperature sensor 58 that detects the temperature of the evaporator 20. .

The operation of the conventional refrigerator 11 configured as described above will be described below.

First, the refrigerator 11 is in the cooling stop state (hereinafter, this operation is referred to as the “OFF mode”) in which the fan 23, the compressor 56, and the evaporator fan 50 are all stopped. In this OFF mode, when the temperature detected by the FCC temperature sensor 54 is lower than the predetermined value FCC_ON temperature, and the temperature detected by the PCC temperature sensor 55 rises to the predetermined value PCC_ON temperature, the following operation is performed. That is, 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, the main condenser 21 side of the lower machine room 15 partitioned by the partition 22 is negative pressure driven by the fan 23 and the external air is sucked from the plurality of intake ports 26 formed in the bottom plate 25. The pressure on the side of the compressor 56 and the evaporation plate 57 becomes positive, and the air in the lower machine room 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 supplied to the anti-dew pipe 60 after condensing while leaving part of the gas in the main condenser 21 while exchanging heat with the outside air. The refrigerant passing through the dew protection pipe 60 radiates heat through the housing 12 and condenses while warming the opening of the freezing chamber 18. The liquid refrigerant condensed by the dewproof pipe 60 passes through the two-way valve 61, then the water is removed by the dryer 137, the pressure is reduced by the throttle 45, and it exchanges heat with the air in the refrigerator compartment 17 while evaporating by the evaporator 20. Then, while cooling the refrigerating chamber 17, the refrigerant is returned to the compressor 56 as a gaseous refrigerant.

When the temperature detected by the FCC temperature sensor 54 falls to the predetermined value FCC_OFF temperature and the temperature detected by the PCC temperature sensor 55 falls to the predetermined value PCC_OFF temperature during the PC cooling mode, the mode is shifted to the OFF mode.

When the temperature detected by the FCC temperature sensor 54 rises to the predetermined value FCC_ON temperature and the temperature detected by the PCC temperature sensor 55 falls to the predetermined value PCC_OFF temperature in the PC cooling mode, the following operation is performed. That is, 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. Hereinafter, the freezer compartment 18 is cooled by heat exchange between the air in the freezer compartment 18 and the evaporator 20 by operating the refrigeration cycle in the same manner as PC cooling (hereinafter, this operation is referred to as “FC cooling mode”) .

When the temperature detected by the FCC temperature sensor 54 falls to the predetermined value FCC_OFF temperature and the temperature detected by the PCC temperature sensor 55 falls to the predetermined value PCC_OFF temperature during the FC cooling mode, the mode transitions to the OFF mode.

When the temperature detected by the FCC temperature sensor 54 falls to the FCC_OFF temperature of the predetermined value and the temperature detected by the PCC temperature sensor 55 rises to the PCC_ON temperature of the predetermined value or higher during the FC cooling mode, the PC cooling mode is set. Transition.

Here, the control at the time of defrosting of the conventional refrigerator will be described based on FIG.

When the integrated operation time of the compressor 56 reaches a predetermined time, the mode shifts to a defrost mode in which the frost attached to the evaporator 20 is heated and melted. In the section p of the defrosting mode, first, in order to suppress the temperature rise of the freezing room 18, the freezing room 18 is cooled for a predetermined time as in the FC cooling mode. Next, in the section q, by closing the two-way valve 61 while operating the compressor 56, the refrigerant remaining in the dryer 137 and the evaporator 20 is recovered to the main condenser 21 and the dew proof pipe 60. Then, in section r, the main condenser 21 and the dew proof pipe 60 are connected to the main condenser 21 and the dew proof pipe 60 via a seal portion such as a valve (not shown) that divides the high pressure side and the low pressure side inside the compressor 56 by stopping the compressor 56 By making the recovered high pressure refrigerant flow back to the evaporator 20, the evaporator 20 is heated using the high pressure refrigerant further heated by the waste heat of the compressor 56. Thereafter, in the section s, the defrost heater (not shown) attached to the evaporator 20 is energized to complete defrosting when the DEF temperature sensor 58 reaches a predetermined temperature. Then, in the section t, the two-way valve 61 is opened to equalize the inside of the refrigeration cycle, and the normal operation is resumed from the section u.

By heating the evaporator using the high pressure refrigerant of the refrigeration cycle and the waste heat of the compressor by the operation described above, the electric energy of the defrost heater can be reduced, and energy saving in the refrigerator can be achieved. Can be

Unexamined-Japanese-Patent No. 4-194564

However, in the conventional refrigerator configuration, when using the high pressure refrigerant collected in the main condenser 21 and the dew proof pipe 60 for defrosting of the evaporator 20, the heat protection with the periphery of the opening of the freezer compartment 18 is prevented. As the temperature of the dew pipe 60 decreases, the high pressure refrigerant in the main condenser 21 maintained at almost the outside air temperature condenses inside the dew protection pipe 60. As a result, the high pressure decreases and the amount of refrigerant flowing from the dew protection pipe 60 into the evaporator 20 decreases, which causes the power consumption of the defrost heater not to be sufficiently reduced.

Therefore, when using the recovered high pressure refrigerant for defrosting of the evaporator 20, it has been a problem to maintain a high pressure.

Moreover, in the conventional refrigerator configuration, although the compressor 56 is operated when recovering the refrigerant, the temperature of the evaporator 20 is excessively lowered due to the operation of the compressor 56, so that sufficient refrigerant recovery can not be performed. .

Therefore, when using the recovered high-pressure refrigerant for defrosting of the evaporator 20, the amount of high-pressure refrigerant flowing into the evaporator 20 is small, and the temperature rise of the evaporator 20 is small, and the electric power of the defrost heater is sufficient It was a problem that it could not be reduced.

Further, in order to increase the amount of high-pressure refrigerant flowing into the evaporator 20 as much as possible, the temperature around the evaporator 20 is low even if the time for recovering the refrigerant is extended, so the refrigerant is inside the evaporator 20. It tends to stay and the recovery time of the staying refrigerant becomes long. The fact that the recovery time of the staying refrigerant is long means that the whole defrosting time for energizing the heater for raising the temperature of the evaporator 20 to a predetermined temperature is longer, that is, the inside of the cold room 17 and the freezing room 18. The internal temperature of the refrigerator tends to rise because the non-cooling time of Therefore, not only the cooling operation time after defrosting becomes long, but there is also a problem that the temperature of the stored food also rises and the freshness maintenance property is deteriorated.

The present invention, when utilizing the recovered high-pressure refrigerant for defrosting of the evaporator, shortens the recovery time of the staying refrigerant while suppressing an excessive decrease in the evaporator temperature, and saves energy by shortening the defrosting time. To provide a refrigerator capable of improving food preservation by suppressing the temperature rise inside the storage unit.

The refrigerator according to the present invention comprises a refrigeration cycle having at least a compressor, an evaporator, a main condenser, and a dew proof pipe, and a flow path switching valve connected to the downstream side of the main condenser; A dew protection pipe connected downstream, and a bypass path connected in parallel to the dew protection pipe and having a heat exchange portion that thermally couples a part with the compressor. In addition, the refrigerator of the present invention is provided with a freezer compartment damper and a refrigerator compartment damper which respectively control cold air supplied to the freezer compartment and the refrigerator compartment which are sectioned by the heat insulation wall. When defrosting the evaporator, the refrigerator according to the present invention fully closes the flow path switching valve and opens the refrigerator compartment damper during operation of the evaporator fan and compressor provided in the vicinity of the evaporator, and the freezer compartment damper Is closed, the stagnant refrigerant in the evaporator and the dew protection pipe is recovered. Thereafter, the compressor is stopped and the flow path switching valve is opened to the bypass path side to supply the recovered high pressure refrigerant to the evaporator. After the predetermined time, the defrost heater provided in the vicinity of the evaporator is energized.

With this configuration, it is possible to recover a sufficient amount of refrigerant without excessively lowering the evaporator temperature at the time of refrigerant recovery, and also shorten the recovery time, so the whole defrosting time, that is, the non-cooling time is shortened and only power consumption is reduced. Not only that, the temperature rise of the food itself stored in the refrigerator is also mitigated. Furthermore, when utilizing the recovered high pressure refrigerant for defrosting of the evaporator, the power amount of the defrost heater can be stably reduced by suppressing the fluctuation of the pressure.

In addition, when the recovered high pressure refrigerant is used for defrosting of the evaporator, the high pressure refrigerant is supplied to the evaporator via the bypass path, and the bypass path and the compressor are thermally coupled. By collecting the waste heat of the compressor at the time of supply and using it for heating the evaporator, the amount of electric power of the defrost heater can be further reduced.

The refrigerator according to the present invention can stably reduce the amount of power of the defrost heater by recovering the refrigerant in the refrigeration cycle to the main condenser and using it for heating the evaporator, thereby saving energy in the refrigerator. Can be

FIG. 1 is a longitudinal sectional view of a refrigerator according to a 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. 3A is an enlarged schematic view of a main part of a heat exchange unit with the compressor of the refrigerator according to the first embodiment of the present invention. FIG. 3B is a schematic cross-sectional view of main parts of a heat exchange unit with a compressor of the refrigerator according to the first embodiment of the present invention. FIG. 4 is a configuration diagram showing a cooling chamber of the refrigerator in the first embodiment of the present invention. FIG. 5 is a diagram showing control at the time of defrosting of the refrigerator in the first embodiment of the present invention. FIG. 6 is a longitudinal sectional view of a conventional refrigerator. FIG. 7 is a block diagram of a conventional refrigerator. FIG. 8 is a diagram showing control at the time of defrosting of the conventional refrigerator.

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

First Embodiment
FIG. 1 is a longitudinal sectional view of a refrigerator according to a 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. 3A is an enlarged schematic view of a main part of a heat exchange unit with a compressor of the refrigerator according to the first embodiment of the present invention. FIG. 3B is a schematic cross-sectional view of main parts of a heat exchange unit with a compressor of the refrigerator according to the first embodiment of the present invention. FIG. 4 is a configuration diagram showing a cooling chamber of the refrigerator in the first embodiment of the present invention. FIG. 5 is a diagram showing control at the time of defrosting of the refrigerator in the first embodiment of the present invention.

As shown in FIGS. 1, 2 and 3A, 3B, the refrigerator 11 includes a housing 12, a door 13, a leg 14 for supporting the housing 12, a lower machine room 15 provided at the lower part of the housing 12, and a housing An upper machine room 16 provided at the upper part of the body 12, a refrigerating room 17 arranged at the upper part of the housing 12, and a freezing room 18 arranged at the lower part of the housing 12. Further, as a component constituting the refrigeration cycle, the refrigerator 11 is housed in the compressor 19 housed in the upper machine room 16, the evaporator 20 housed on the rear side of the freezer room 18, and the lower machine room 15. A main condenser 21 is provided. Further, the refrigerator 11 has a partition 22 for dividing the lower machine room 15, a fan 23 attached to the partition 22 for air cooling the main condenser 21, an evaporation tray 24 installed on the downwind side of the partition 22, and a bottom plate of the lower machine room 15. It has 25.

Here, the compressor 19 is a variable speed compressor, and uses six revolutions selected from 20 rps to 80 rps. This is to adjust the refrigeration capacity by switching the number of rotations of the compressor 19 from low speed to high speed in six stages while avoiding resonance of piping and the like. The compressor 19 operates at a low speed at start-up, and accelerates as the operation time for cooling the refrigerating chamber 17 or the freezing chamber 18 becomes longer. This is mainly to use the most efficient low speed, and to use a relatively high rotational speed appropriate to the increase in the load of the refrigerator compartment 17 or the freezer compartment 18 due to the high outside air temperature, the opening and closing of the door 13, etc. It is. At this time, although the rotational speed of the compressor 19 is controlled independently of the cooling operation mode of the refrigerator 11, the rotational speed at the start of the PC cooling mode having a high evaporation temperature and a relatively large refrigeration capacity is You may set it lower than time. In addition, as the temperature of the refrigerator compartment 17 or the freezer compartment 18 decreases, the refrigeration capacity may be adjusted while decelerating the compressor 19.

The refrigerator 11 also includes a plurality of intake ports 26 provided in the bottom plate 25, a discharge port 27 provided on the back side of the lower machine room 15, and a series connecting the upper machine room 16 with the discharge port 27 of the lower machine room 15. There is a ventilation passage 28. Here, the lower machine room 15 is divided into two rooms by the partition wall 22, and the main condenser 21 is accommodated on the windward side of the fan 23, and the evaporation pan 24 is accommodated on the windward side.

Moreover, as a component which comprises a refrigerating cycle, the refrigerator 11 is located in the downstream of the main condenser 21, and the dryer 38 which dries the refrigerant | coolant which circulates is located in the downstream of the dryer 38, and controls the flow of a refrigerant | coolant A flow path switching valve 40 and a dew protection pipe 41 located downstream of the flow path switching valve 40 and thermally coupled to the outer surface of the housing 12 around the opening of the freezing chamber 18 are provided. Furthermore, the refrigerator 11 connects the downstream side of the flow path switching valve 40 and the evaporator 20 in parallel with the dew protection pipe 41 and the throttle 42 connecting the dew protection pipe 41 and the evaporator 20 as parts constituting a refrigeration cycle And a heat exchange portion 44 thermally coupled to the compressor 19 in the path of the bypass path 43.

Here, the heat exchange portion 44 of the bypass passage 43 thermally coupled to the compressor 19 is installed on the surface of the closed container 70 forming the outer shell of the compressor 19 and thermally conductive to thermally couple the bypass passage 43 and the closed container 70. Butyl rubber 71 and an aluminum foil tape 72 for fixing the heat conductive butyl rubber 71 to the closed container 70. As shown in FIG. 3B, the thermally conductive butyl rubber 71 has a thermal conductivity of 2.1 W / mK and a thickness of 1 mm and a width of 10 mm, and is installed so as to sandwich a bypass path 43 which makes one round around the upper and lower center of the closed container 70. . As a result, a sufficient amount of heat exchange between the bypass passage 43 and the closed container 70 of the compressor 19 can be secured, and the high pressure refrigerant passing through the bypass passage 43 is heated by the heat exchange unit 44 to be substantially gaseous. It can be in the state. The same effect can be expected even if the bypass path 43 and the sealed container 70 are thermally coupled using a metal having a high thermal conductivity, such as solder or brazing material, instead of the thermally conductive butyl rubber 71. And the rustproofing treatment of the thermal joint is required. When the heat conductive butyl rubber 71 is used, there is an advantage that it can be used after rustproof coating is applied to the closed container 70, and an effect of suppressing transmission of the vibration of the compressor 19 to the bypass path 43 can also be expected. The closed container 70 has a mass ratio of about 40% of the compressor 19, and it is estimated that the compressor 19 holds about 40% of the waste heat stored in the sensible heat, and the refrigerant in the compressor 19 The heat exchange portion 44 is formed on the surface of the sealed container 70 because it is thermally coupled to the waste heat stored in the mechanical components inside the compressor 19 and the like via a refrigerator oil (not shown) and a refrigerator oil (not shown). For example, the waste heat that the compressor 19 stores sensible heat can be effectively used.

In the present embodiment, the heat exchange unit 44 thermally coupled to the compressor 19 is provided outside the compressor 19, but may be thermally coupled to the inside of the compressor. Although not shown, the compressor 19 is installed inside the hermetic container 70 and is used to lubricate the compression mechanism, a piston that forms the compression mechanism, a cylinder, a shaft, a motor unit that drives the compression mechanism via the shaft, and the compression mechanism. Equipped with refrigeration oil. Here, in order to exchange heat inside the compressor 19, a part of the bypass path 43 penetrates the closed container 70 and is installed in the refrigeration oil staying in the lower part of the closed container 70. Form a heat exchange portion to be coupled. With this configuration, a sufficient amount of heat exchange between the bypass passage 43 and the sealed container 70 can be secured, and the high-pressure refrigerant passing through the bypass passage 43 is heated by the heat exchange unit inside the compressor 19 It can be in the state of In addition, since the heat exchange coupling between the bypass passage 43 and the closed container 70 is realized without impairing the heat release from the surface of the closed container 70, the heat release of the compressor 19 is lost during normal cooling operation and the temperature rises. The efficiency of the machine 19 does not decrease.

With this configuration, it is possible to secure a sufficient amount of heat exchange between the bypass passage 43 and the closed container 70 of the compressor 19 without impairing the heat radiation from the surface of the closed container 70, and further achieve energy saving in the refrigerator. .

In the present embodiment, the bypass path 43 uses a copper pipe having an outer diameter of 2 mm and an inner diameter of 1 mm, which is smaller than the diameter of the main condenser 21 and the pipe on the upstream side of 4 mm. As a result, in the heat exchange section 44 thermally coupled to the compressor 19 in the path of the bypass path 43, the pressure is slightly reduced from the main condenser 21, and heat exchange in the heat exchange section 44 is facilitated. The inner diameter of the bypass path 43 may be φ0.5 to φ3 in consideration of workability. In the present embodiment, the efficiency of heat exchange is improved by the diameter of the bypass passage 43. However, a restriction adjustment mechanism such as an expansion valve is provided between the heat exchange unit 44 thermally coupled to the compressor 19 and the main condenser 21. Even the same effect can be obtained.

Further, as shown in FIG. 2, the flow path switching valve 40 can control the flow of the refrigerant independently of the dew proof pipe 41 and the bypass path 43. Normally, the flow path switching valve 40 keeps the flow path from the main condenser 21 to the dew proof pipe 41 open and keeps the flow path from the main condenser 21 to the bypass path 43 closed. The flow path is opened and closed only at the time of defrosting, which will be described later.

As an air path configuration in the present embodiment, there is a cooling chamber 73 on the back of the freezing chamber 18, the evaporator 20 is disposed in the cooling chamber 73, and the evaporator 20 has an evaporation fan 30. It is covered with a vessel cover (not shown). The cold air generated in the evaporator 20 is blown into the refrigerating chamber 17 and the freezing chamber 18 by the evaporator fan 30 in the vicinity of the evaporator.

Cold air is blown through the evaporator cover into the inside of the freezer compartment 18 to circulate and cool the inside of the freezer compartment 18, and the circulation-cooled cold air is provided in the lower part of the evaporator cover (refrigeration room return port (illustrated Return to the cooling chamber 73). During this time, the freezer compartment damper 31 which shuts off the flow of the freezer compartment cold air is arranged. Further, an FCC temperature sensor 34 for detecting the temperature of the freezing chamber 18 is disposed in the freezing chamber 18.

On the other hand, the flow of cold air blown toward the refrigerator compartment 17 is controlled by opening and closing of the refrigerator compartment damper 32 for blocking the cold air supplied to the refrigerator compartment 17. The cold air flowing into the refrigerator compartment 17 is controlled while the refrigerator compartment damper 32 is opened and closed so that the refrigerator compartment temperature detected by the PCC temperature sensor 35 becomes equal to the target compartment temperature. Cold air having passed through the refrigerator compartment damper 32 is blown into the refrigerator compartment 17 through the duct 33 for supplying cold air to the refrigerator compartment 17 and is circulated in the refrigerator compartment 17 and then evaporated as shown in FIG. It returns to the cooling chamber 73 through the refrigerator compartment return duct 102 which passes the side of the vessel 20. The duct 33 is formed along the wall surface where the cold storage room 17 and the upper machine room 16 are adjacent, and discharges a part of the cold air passing through the duct 33 from near the center of the cold room, and the upper machine room 16 After passing while cooling adjacent wall surfaces, the air is discharged into the refrigerator compartment 17 from the outlet of the duct 33 provided at the upper part of the refrigerator compartment 17.

Next, the configuration around the evaporator in the present embodiment will be described.

A cooling chamber 73 is provided on the back of the refrigerator main body 11, and an evaporator 20 for generating cold air of fin and tube type as a representative is disposed on the back of the freezing chamber 18 in the cooling chamber 73. . Inside the front storage of the cooling chamber 73, an evaporator cover (not shown) is disposed which covers the evaporator 20 having a freezer compartment cold air return port for the cold air that has cooled the freezer compartment 18 to return to the evaporator 20. There is. Moreover, aluminum or copper is used as a material of the evaporator 20.

The evaporator cover is composed of an evaporator front side cover inside the storage and an evaporator rear side cover on the evaporator side, and on the evaporator side of the evaporator rear side cover, a metal heat transfer promotion member (shown in the figure) ) Is placed. In the present embodiment, an aluminum foil of t = 8 μm is attached for promoting heat transfer at the time of defrosting in consideration of the cost. The upper and lower dimensions of the aluminum foil are from the lower end to the upper end of the evaporator 20, and the left and right dimensions are larger from the end of the fin of the evaporator 20 to about +15 mm. By sticking this aluminum foil, heat transfer at the time of defrosting is promoted, and the shortening effect of defrosting time by defrosting efficiency improvement is acquired. In addition, you may arrange | position aluminum foil in the inner box of the back side of the evaporator 20, in order to acquire the further effect. Furthermore, when it comprises an aluminum plate plate having a thickness larger than that of aluminum foil, or a material having a thermal conductivity higher than that of aluminum (for example, copper), the effect of promoting heat transfer is further exhibited.

An evaporator fan 30 for blowing cold air generated by the evaporator 20 to the refrigerator compartment 17 and the freezer compartment 18 by forced convection is arranged in the vicinity of the evaporator 20 (for example, the upper space), and cooling is performed below the evaporator 20 A glass tube heater made of glass tube is provided as a defrost heater 37 for defrosting the frost adhering to the evaporator 20 and the evaporator fan 30 sometimes. A cover (not shown) covering the glass tube heater 37 is disposed above the glass tube heater 37. The cover covering the defrosting heater 37 prevents evaporation noise such as juice which may be generated when water droplets dropped from the evaporator 20 at the time of defrosting fall directly on the surface of the glass tube which has become hot due to defrosting. In addition, the dimensions and dimensions are equal to or greater than the glass tube diameter and width.

Below the defrost heater 37, the evaporation dish 24 which receives the defrost water which the frost adhering to the evaporator 20 melt | dissolves and falls falls is arrange | positioned.

As shown in FIG. 4, the right side surface of the evaporator 20 is provided with a cold storage room return duct 102 in which cold air obtained by cooling the cold storage room 17 is returned to the evaporator 20, and cold air introduced by the cold storage room return duct 102 is At the lower part of the evaporator 20, it joins with the freezer compartment cold air from the freezer compartment return port, and flows to the evaporator 20 to exchange heat again.

Here, as a refrigerant of the recent refrigeration cycle, isobutane which is a flammable refrigerant having a small global warming potential is used from the viewpoint of global environmental protection. This hydrocarbon, isobutane, has a specific gravity about twice that of air at room temperature and atmospheric pressure (at 2.04 and 300 K). As a result, the amount of refrigerant charged can be reduced as compared with the prior art, and at the same time the cost is low, the amount of leakage when the flammable refrigerant should leak by any chance is reduced, and safety can be further improved.

In the present embodiment, isobutane is used as the refrigerant, and the maximum temperature of the surface of the glass tube, which is an outer shell of the defrost heater 37 at the time of defrosting, is regulated as an explosion proof. Therefore, in order to reduce the temperature of the surface of the glass tube, a double glass tube heater in which the glass tube is formed in double is adopted. Besides, as a configuration for reducing the temperature of the surface of the glass tube, a member with high heat dissipation (for example, aluminum fins) can be wound around the surface of the glass tube. At this time, the outer dimensions of the defrost heater 37 can be reduced by making the glass tube single-layered.

In addition to the defrost heater 37, you may use together the pipe heater closely_contact | adhered to the evaporator 20 as a structure which improves the efficiency at the time of a defrost. In this case, defrosting of the evaporator 20 is efficiently performed by direct heat transfer from the pipe heater, and the frost adhering to the evaporating dish 24 and the evaporator fan 30 around the evaporator 20 is removed by the defrosting heater 37 Since the melting can be performed, the defrosting time can be shortened, and the energy saving and the rise in the temperature in the refrigerator during the defrosting time can be suppressed.

Among them, the evaporator 20 in the present embodiment is a typical fin-and-tube evaporator 20 as in the commonly used evaporator 20, and the refrigerant pipe having fins is vertically Is stacked on. The evaporator 20 has a configuration in which 30 refrigerant pipes are provided by arranging 10 stages of refrigerant pipes generally in the vertical direction and arranging 3 rows of refrigerant pipes in the front-rear direction. In addition, the refrigerant pipe in the evaporator 20 in the present embodiment has a configuration in which the width dimension of the lower portion is shorter than that of the upper portion.

Here, as the configuration around the evaporator of the refrigeration cycle in the present embodiment, at the inlet of the evaporator 20, the outlet of the throttle 42 and the outlet of the bypass passage 43 are connected by joining a Y-shaped joint pipe, The evaporator outlet of the evaporator 20 is connected to a pipe leading to the compressor 19. The evaporator 20 has a DEF temperature sensor 36 for detecting the temperature of the evaporator 20 as shown in FIG. 1, and the DEF temperature sensor 36 is disposed at the inlet pipe portion of the evaporator 20.

The temperature detected by the FCC temperature sensor 34 is lower than the predetermined value of the FCC_ON temperature in the cooling stop state where the air cooling fan 23, the compressor 19, and the evaporator fan 30 are all stopped (hereinafter, this operation is referred to as "OFF mode"). When the temperature is low and the temperature detected by the PCC temperature sensor 35 rises to the PCC_ON temperature of a predetermined value, the following operation is performed. That is, the freezer compartment damper 31 is closed, the refrigerator compartment damper 32 is opened, and the air cooling fan 23, the compressor 19, and the evaporator fan 30 are driven (hereinafter, this operation is referred to as "PC cooling mode").

In the PC cooling mode, the main condenser 21 side of the lower machine room 15 partitioned by the partition wall 22 becomes negative pressure by the driving of the air cooling fan 23, and external air is sucked from the plurality of intake ports 26. The evaporation dish 24 side becomes positive pressure, and the air in the lower machine room 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 part of the gas in the main condenser 21 while exchanging heat with the outside air, and then the water is removed by the dryer 38. The dew pipe 41 is supplied. The refrigerant having passed through the anti-dew pipe 41 dissipates heat through the casing 12 while warming the opening of the freezing chamber 18 and then condenses, and then the pressure is reduced by the throttle 42 and evaporated in the evaporator 20. While exchanging heat with the internal air to cool the refrigerating chamber 17, the refrigerant is returned to the compressor 19 as a gaseous refrigerant.

When the temperature detected by the FCC temperature sensor 34 falls to the predetermined value FCC_OFF temperature and the temperature detected by the PCC temperature sensor 35 falls to the predetermined value PCC_OFF temperature during the PC cooling mode, the mode transitions to the OFF mode.

When the temperature detected by the FCC temperature sensor 34 rises to the predetermined value FCC_ON temperature and the temperature detected by the PCC temperature sensor 35 decreases to the predetermined value PCC_OFF temperature during the PC cooling mode, the following operation is performed. That is, the freezer compartment damper 31 is opened, the refrigerator compartment damper 32 is closed, and the compressor 19, the air cooling fan 23, and the evaporator fan 30 are driven. Hereinafter, the freezer compartment 18 is cooled by heat exchange between the air in the freezer compartment 18 and the evaporator 20 by operating the refrigeration cycle in the same manner as PC cooling (hereinafter, this operation is referred to as “FC cooling mode”) .

When the temperature detected by the FCC temperature sensor 34 falls to the FCC_OFF temperature of the predetermined value and the temperature detected by the PCC temperature sensor 35 indicates a temperature lower than the PCC_ON temperature of the predetermined value during the FC cooling mode, transition to the OFF mode Do.

In the FC cooling mode, when the temperature detected by the FCC temperature sensor 34 falls to the FCC_OFF temperature of the predetermined value and the temperature detected by the PCC temperature sensor 35 indicates the PCC_ON temperature or more of the predetermined value, the PC cooling mode is set. Transition.

In the PC cooling mode, the temperature detected by the FCC temperature sensor 34 indicates a temperature higher than the predetermined value FCC_ON temperature due to the opening / closing of the door 13 of the freezer compartment 18 or the like, or the refrigerator compartment 17 in the FC cooling mode. When the temperature detected by the PCC temperature sensor 35 indicates a temperature higher than the PCC_ON temperature of the predetermined value due to the opening and closing of the door 13, the freezer compartment damper 31 is opened and the refrigerator compartment damper 32 is also opened. The freezer compartment can be cooled (hereinafter, this operation is referred to as “PC + FC cooling mode”).

Next, the driving operation at the time of defrosting of the refrigerator of the present embodiment will be described.

As shown in FIG. 5, there are three types of states of the flow path switching valve 40: “open / close”, “closed / opened” and “closed / closed”. The state “open / close” of the flow path switching valve 40 means that the flow path from the main condenser 21 to the dew proof pipe 41 is opened and the flow path from the main condenser 21 to the bypass path 43 is blocked. The state “closed and open” of the flow path switching valve 40 means that the flow path from the main condenser 21 to the dew proof pipe 41 is closed and the flow path from the main condenser 21 to the bypass path 43 is opened. The state “closed / closed” of the flow path switching valve 40 means that the flow path from the main condenser 21 to the dew proof pipe 41 is closed and the flow path from the main condenser 21 to the bypass path 43 is closed. .

The time chart of FIG. 5 shows control at the time of defrosting of this embodiment.

When the integrated operation time of the compressor 19 or the time elapsed after the previous defrosting operation reaches a predetermined time, the mode shifts to a defrost mode in which the frost on the evaporator 20 is heated and melted.

In the defrosting mode section a, first, in order to suppress the temperature rise of the refrigerator compartment 17, the refrigerator compartment 17 and the freezer compartment 18 are cooled for a predetermined time as in the PC + FC cooling mode. Then, in order to suppress the temperature rise of the freezer compartment 18 which is easily affected by the temperature rise at the time of defrosting, the freezer compartment 18 is cooled for a predetermined time as in the FC cooling mode. In addition, since there is a possibility that the stored food may freeze when the temperature in the cold storage room 17 becomes 0 ° C. or lower, depending on the case, the PC + FC cooling mode may be omitted and only the FC cooling mode may be set.

Next, in section b, the flow from the main condenser 21 to the dewproof pipe 41 and the bypass path 43 is achieved by setting the flow passage switching valve 40 to be fully closed while the flow passage switching valve 40 is fully closed while operating the compressor 19. The passages are closed together, and the refrigerant remaining in the dewproof pipe 41 and the evaporator 20 and the bypass passage 43 is recovered to the main condenser 21.

Then, in section c, the compressor 19 is stopped, and the flow path switching valve 40 is switched to open the flow path from the main condenser 21 to the bypass path 43, thereby bypassing the bypass path 43. The high pressure refrigerant collected in the main condenser 21 is supplied to the evaporator 20 via the. At this time, the high-pressure refrigerant is heated by the waste heat of the stopped compressor 19 in the heat exchange unit 44 provided in the bypass path 43, and the dryness is increased. This is because when the high pressure refrigerant is recovered by the main condenser 21 in the section b, the heat is dissipated to the outside air and most of the refrigerant condenses. Therefore, in addition to the sensible heat of the high pressure refrigerant maintained at the outside air temperature, the heat due to the latent heat of condensation is evaporated in comparison with the case where the high pressure refrigerant is supplied to the evaporator 20 without being heated by the heat exchange unit 44 in section c. Can be added to the vessel 20.

Next, in the section d, the defrost heater 37 attached to the evaporator 20 is energized to complete the defrosting. The completion of the defrosting is judged by the DEF temperature sensor 36 reaching a predetermined temperature.

Then, in the section e, the flow path switching valve 40 is switched to close the flow path from the main condenser 21 to the bypass path 43, and the flow path from the main condenser 21 to the dewproof pipe 41 To equalize the inside of the refrigeration cycle, and resume normal operation from section f.

In this series of operations, in section b, the evaporator fan 30 is also operating while the compressor 19 is operating. As a result, the quality of the compressor can be improved by suppressing an excessive temperature drop of the evaporator 20, and the time for collecting the staying refrigerant can be shortened, so that the time can be shortened. Furthermore, since a sufficient amount of refrigerant can be supplied when supplying the refrigerant from the main condenser 21 to the evaporator 20 in the section c after the section b, the temperature raising effect in the evaporator 20 is enhanced, and the defrosting in the section c Energy saving can be achieved by shortening the defrosting time by the heater 37. If the defrosting time is short, the non-cooling time for stopping the compressor 19 is also short, so that the temperature rise of the food itself can be suppressed. This is also a favorable condition for food storability that is degraded by temperature fluctuations.

Note that operating the evaporator fan 30 in section b makes it possible to use heat of sensible heat change and latent heat change in which the refrigerant changes phase in the evaporator 20, and open the refrigerator compartment damper 32, and the freezer compartment damper 31 The cold air blown into each chamber is also heated by the influence of the temperature rise of the evaporator 20 due to the operation of the evaporator fan 30. However, since the freezer compartment damper 31 is closed, air can not be blown to the freezer compartment 18 and only the refrigeration compartment 17 can be cooled because only the refrigerating compartment 17 can be ventilated. The temperature rise in 17 can be suppressed, and the deterioration of the food stored in the refrigerator can be suppressed. Further, the temperature of the evaporator itself is also raised by the return air that has passed through the refrigerator compartment return duct 102 from the refrigerator compartment 17 by the operation of the evaporator fan 30, so that the start temperature at the time of heater defrosting in section c also becomes high. It also saves energy and saves time.

In addition, the second DFC temperature sensor 110 is provided near the evaporator outlet of the evaporator 20, and the temperature of the second DFC temperature sensor 110 is a predetermined temperature during the refrigerant recovery operation to the main condenser 21 in section b. The refrigerant recovery operation may be ended when In this case, when the refrigerant in the refrigeration cycle is recovered to the main condenser 21, the temperature of the evaporator 20 starts to rise from the evaporator inlet side, and the temperature on the outlet side of the evaporator 20 rises with a delay. By detecting the temperature near the outlet of the evaporator 20, the refrigerant remaining in the evaporator 20 can be reliably recovered. Therefore, the power amount of the defrost heater 37 in the section d can be stably reduced by stably securing the supplied refrigerant when using for heating in the section c, and energy saving in the refrigerator can be achieved. .

Further, the end of the refrigerant recovery operation in the section b is ended when the temperature detected by the DFC temperature sensor 36 or the second DFC temperature sensor 110 shown in FIG. The refrigerant in the refrigeration cycle including the evaporator 20 can be reliably recovered to the main condenser 21. Furthermore, by using the second DFC temperature sensor 110 disposed at the evaporator outlet of the evaporator 20, it is possible to detect an outlet side temperature at which the temperature rise is slow because there is an accumulator at the time of refrigerant recovery. . Furthermore, it is possible to finish in the optimal refrigerant recovery time. Therefore, since the time for the defrosting operation is shortened, the time required for defrosting, that is, the non-cooling time for not cooling the interior is shortened, energy saving in the refrigerator is achieved, and the rise in the interior temperature is also suppressed. Can be suppressed. In addition, the time taken for defrosting is shortened and the internal temperature is less likely to rise, so that the cooling time after defrosting can be shortened, and the heat load to which defrost heater 37 is energized is also taken into consideration as a whole. Energy saving in

Further, in the present embodiment, the outlet of the bypass path 43 is connected to the inlet side of the evaporator 20. Thus, in the refrigeration cycle of the refrigerator, the outlet of the throttle 42, that is, the inlet of the evaporator 20 is not likely to rise in temperature during defrosting, and a DFC temperature sensor 36 for detecting the temperature is disposed. It is judged that the defrosting is completed by detecting the temperature of. Then, the temperature of the inlet of the evaporator 20 is raised in advance by connecting the outlet of the bypass passage 43 so as to supply the high-pressure refrigerant from the inlet side of the evaporator 20 where the temperature does not easily rise. Is promoting.

Since the outlet of the bypass path 43 is connected to the inlet side of the evaporator 20, the temperature rise can be detected using the DFC temperature sensor 36 already provided. This makes it possible to provide a refrigerator with high cost performance without the need for cost increase.

Note that the section d may be started before the end of the section c. In this case, in section c, the compressor 19 is stopped, the flow path switching valve 40 is switched, and the flow path from the main condenser 21 to the bypass path 43 is opened, whereby the high pressure refrigerant recovered in the main condenser 21 Is supplied to the evaporator 20, and the refrigerant supplied inside the evaporator 20 is condensed to increase the evaporator temperature due to the heat of condensation. At this time, by shifting to section d and starting energization of the defrost heater 37 before the temperature of the evaporator 20 reaches the maximum temperature, a temperature drop loss after exceeding the maximum temperature in the section c occurs. Instead, the temperature of the evaporator 20 can be effectively raised. In the present embodiment, the temperature of the evaporator 20 in the section c is detected by the DFC temperature sensor 36. However, a method of detecting the temperature of the evaporator 20 by the second DFC temperature sensor 110 may be used. It is good also as time control to decide. Alternatively, switching control may be performed by both temperature and time. In this case, even if the amount of frost adhering to the evaporator 20 changes due to, for example, the opening and closing of the door 13, the heat loss to be supplied at the time of defrosting due to the section switching does not occur.

Further, in the present embodiment, the state of the refrigerant in section c is grasped by detecting the temperature of the evaporator 20 using the DFC temperature sensor 36 which is a temperature sensor, and thereafter the defrost heater 37 is energized in the section d. However, instead of the temperature sensor, a pressure sensor may be used to shift to section d when the high pressure and the low pressure in the evaporator 20 are balanced and balanced.

In the present embodiment, the main condenser 21 is a forced air-cooling type condenser, but a second dew protection pipe thermally coupled to the side surface or the back surface of the housing 12 may be used. Unlike the dew protection pipe 41 thermally coupled to the periphery of the opening of the refrigerator compartment 17 and the freezing compartment 18, the second dew protection pipe thermally coupled to the side surface and the back surface of the housing 12 has an outside air temperature even while the compressor 19 is stopped. The same effect can be expected even when used as the main condenser 21 since it is maintained in the vicinity.

In the present embodiment, although the flow path switching valve 40 and the evaporator 20 are connected by the bypass path 43, the flow velocity of the high pressure refrigerant supplied to the evaporator 20 at the time of defrosting is too fast and the flow noise is generated. In this case, a flow path resistance for adjusting the flow rate may be connected in series with the bypass path 43.

In the present embodiment, when the compressor 19 is stopped, the high pressure refrigerant is directly supplied to the evaporator 20 without passing through the dew protection pipe 41 and the throttle 42 at the time of defrosting. It prevented that the temperature of the high pressure refrigerant decreased due to the influence of the dew protection pipe 41 which is lower in temperature than that of the refrigerant. However, if the temperature of the evaporator 20 becomes higher than the dew proof pipe 41 due to the progress of the defrosting, the high pressure refrigerant may flow back from the evaporator 20 to the dew proof pipe 41 through the throttle 42. A non-return valve or a two-way valve may be provided to prevent backflow from the outlet 41 into the path of the inlet of the evaporator 20.

In the present embodiment, a glass tube heater is used as the defrost heater 37 at the time of defrosting, but in the case where a pipe heater is combined with the glass tube heater, glass is optimized by optimizing the respective heater capacities. It is possible to reduce the capacity of the tube heater. Since the outer temperature of the glass tube heater at the time of defrosting can also be lowered when the heater capacity is lowered, red heat at the time of defrosting can also be suppressed.

Furthermore, the ability to reduce the input time of the glass tube heater at the time of defrosting means that the temperature rise is suppressed by shortening the non-cooling operation time, and the temperature rise is suppressed due to the heat generation of the glass tube heater itself. There is also an impact on the food being eaten. Frozen food stored in the refrigerator may be frost-burned due to temperature rise during non-cooling operation time during defrosting, heat transfer from the temperature of the glass tube heater itself, inflow of warm air during defrosting, etc. Although it will deteriorate due to the influence of heat fluctuation, in the present embodiment, the deterioration of the food can be suppressed even when stored for a long time.

As described above, the refrigerator in the first disclosure includes a refrigerant switching cycle having at least a compressor, an evaporator, a main condenser, and a dewproof pipe, and a flow path switching valve connected to the downstream side of the main condenser; A dew protection pipe connected to the downstream side of the flow path switching valve, and a bypass path connected in parallel to the dew protection pipe and having a heat exchange portion that thermally couples a part with the compressor. The refrigerator in the first disclosure is provided with a freezer compartment damper and a refrigerator compartment damper which respectively control cold air supplied to a freezer compartment and a refrigerator compartment partitioned by the heat insulation wall. In the refrigerator in the first disclosure, when defrosting the evaporator, the evaporator fan provided in the vicinity of the evaporator and the flow path switching valve are fully closed during operation of the compressor and the refrigerator compartment damper is opened to open the freezer compartment Close the damper. By this operation, after the operation of collecting the stagnant refrigerant in the evaporator and the dew proof pipe, the compressor is stopped and the flow path switching valve is opened to the bypass path side to supply the collected high pressure refrigerant to the evaporator. After a predetermined time, the defrost heater provided in the vicinity of the evaporator is energized.

With this configuration, when the refrigerant in the refrigeration cycle is recovered to the main condenser, the recovery of the refrigerant can be facilitated and the recovery time can be shortened while suppressing an excessive decrease in the evaporator temperature, so that heating of the evaporator can be achieved. In the case of using it, a sufficient amount of refrigerant can be supplied. In addition, the quality of the compressor can also be improved in order to suppress a drop in the evaporator temperature. Therefore, the electric energy of the defrost heater can be stably reduced, and energy saving can be achieved in the refrigerator.

In the first disclosure, the refrigerator in the second disclosure includes the temperature sensor in the vicinity of the outlet of the evaporator, and the recovery operation of the staying refrigerant is performed when the temperature of the temperature sensor reaches a predetermined temperature during the recovering operation of the staying refrigerant. It may be configured to end.

With this configuration, when the refrigerant in the refrigeration cycle is recovered to the main condenser, the temperature of the evaporator starts to rise from the evaporator inlet side, and the temperature on the outlet side of the evaporator is delayed and rises, but the evaporator By detecting the temperature in the vicinity of the outlet, it is possible to reliably recover the staying refrigerant. Therefore, the electric energy of a defrost heater can be stably reduced by securing stably the refrigerant at the time of using for heating, and energy saving in a refrigerator can be aimed at.

In the first disclosure, the refrigerator in the third disclosure includes the temperature sensor in the vicinity of the outlet of the evaporator, and the temperature of the temperature sensor rises from the lowest point by a predetermined value at the time of recovery operation of the staying refrigerant. It is good also as composition which ends operation of recovery.

According to this configuration, the refrigerant in the refrigeration cycle can be reliably recovered to the main condenser, and the refrigerant recovery operation can be completed in an optimal refrigerant recovery time. Therefore, the time for defrosting operation is shortened, the time required for defrosting, that is, the non-cooling time for not cooling the inside of the refrigerator is shortened, energy saving in the refrigerator is achieved, and the temperature rise in the refrigerator is suppressed, and the quality deterioration of food is suppressed. can do. In addition, since the time required for defrosting is shortened and the temperature in the cold storage is difficult to increase, the cooling time after defrosting can be shortened, and the heat load to which the defrost heater is energized is also taken into consideration in the refrigerator as a whole. Energy saving can be achieved.

In the first disclosure, the refrigerator in the fourth disclosure may be configured to connect the outlet of the bypass path to the evaporator inlet side.

In the refrigeration cycle of the refrigerator, the throttle outlet, that is, the evaporator inlet, has a sensor that detects the temperature because temperature increase is difficult during defrosting, and the sensor detects a predetermined temperature to determine the end of defrosting. ing. However, by connecting the outlet of the bypass path to the evaporator inlet side in this way, detection of temperature rise can be performed using an existing temperature sensor, so there is no need for cost increase and cost performance is high. . Furthermore, since the high-pressure refrigerant is supplied from the inlet portion where temperature rise is difficult, the evaporator temperature can be uniformly raised without waste when the defrost heater is energized after a predetermined time. Therefore, energy saving can be further achieved in the refrigerator.

The refrigerator in the fifth disclosure may be configured to connect the outlet of the bypass path to the evaporator inlet side in any one of the second disclosure and the third disclosure.

According to this configuration, by connecting the outlet of the bypass path to the evaporator inlet side, detection of temperature rise can be performed using an existing temperature sensor, so there is no need for cost increase and cost performance is high. Furthermore, since the high-pressure refrigerant is supplied from the inlet portion where temperature rise is difficult, the evaporator temperature can be uniformly raised without waste when the defrost heater is energized after a predetermined time. Therefore, energy saving can be further achieved in the refrigerator.

As described above, the refrigerator according to the present invention recovers the refrigerant remaining in the evaporator and the dew protection pipe in the main condenser, and the high-pressure refrigerant in the refrigeration cycle flows into the evaporator due to the pressure difference to add the evaporator. Since the output of the electric heater for defrosting can be reduced using the energy to warm, it is applicable also to other refrigeration application goods, such as a commercial refrigerator.

11 refrigerator 12 housing 13 door 14 legs 15 lower machine room 16 upper machine room 17 cold room 18 freezer room 19 compressor 20 evaporator 21 main condenser 22 partition 23 fan (air cooling fan)
24 evaporation dish 25 bottom plate 26 air intake 27 exhaust 28 communication air passage 30 evaporator fan 31 freezer compartment damper 32 cold storage room damper 33 duct 34 FCC temperature sensor 35 PCC temperature sensor 36 DEF temperature sensor 37 defrost heater (glass tube heater)
Reference Signs List 38 dryer 40 flow path switching valve 41 dew protection pipe 42 throttle 43 bypass path 44 heat exchange unit 70 closed container 71 heat conductive butyl rubber 72 aluminum foil tape 73 cooling chamber 102 refrigerating chamber return duct 110 temperature sensor (second DFC temperature sensor )

Claims

A refrigeration cycle comprising at least a compressor, an evaporator, a main condenser, and a dew proof pipe, a flow path switching valve connected to the downstream side of the main condenser, and a dew protection connected to the downstream side of the flow path switching valve Cold air supplied to a freezer compartment and a refrigerator compartment, which has a pipe and a bypass passage connected in parallel with the dewproof pipe and having a heat exchange part thermally coupled to the compressor, and partially separated by a heat insulating wall In a refrigerator having a freezer compartment damper and a refrigerator compartment damper for controlling the air conditioner, when the evaporator is defrosted, the evaporator fan provided in the vicinity of the evaporator and the flow during operation of the compressor The refrigerant stored in the evaporator and the dewproof pipe is recovered by fully closing the passage switching valve and opening the refrigerating chamber damper and closing the freezing chamber damper, and then the compression is performed. The high pressure refrigerant recovered is supplied to the evaporator by stopping the flow path switching valve and opening the flow path switching valve to the bypass path side, and after a predetermined time, the defrost heater provided in the vicinity of the evaporator is energized. Refrigerator to do.
The refrigerator according to claim 1, further comprising: a temperature sensor in the vicinity of an outlet of the evaporator, wherein the operation of collecting the staying refrigerant ends when the temperature of the temperature sensor reaches a predetermined temperature during the operation of collecting the staying refrigerant.
The temperature sensor is provided in the vicinity of the outlet of the evaporator, and the recovery operation of the staying refrigerant is ended when the temperature of the temperature sensor rises from the lowest point by a predetermined temperature at the time of the recovering operation of the staying refrigerant. refrigerator.
The refrigerator according to claim 1, wherein an outlet of the bypass path is connected to the evaporator inlet side.
The refrigerator according to any one of claims 2 or 3, wherein an outlet of the bypass path is connected to the evaporator inlet side.