JP6846599B2 - refrigerator - Google Patents

Description

The present invention relates to a refrigerator that reduces the output of an electric heater for defrosting by heating the evaporator by flowing high-pressure refrigerant in the refrigeration cycle into the evaporator due to a pressure difference after the compressor is stopped. is there.

From the viewpoint of energy saving, in household refrigerators, the high-pressure refrigerant in the refrigeration cycle flows into the evaporator due to the pressure difference and uses the energy to heat the evaporator to reduce the output of the electric heater for defrosting. There is. This is because the high-pressure refrigerant stored inside the condenser of the refrigeration cycle is maintained near the outside air temperature even after the compressor is stopped, while the evaporator is in a low temperature state of -30 to -20 ° C. By increasing the amount of heat flowing into the evaporator due to the pressure difference, or by increasing the enthalpy of the inflowing high-pressure refrigerant to increase the amount of heat flowing in, the output of the defrosting electric heater is positively reduced to save energy. It is intended.

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

FIG. 4 is a vertical cross-sectional view of a conventional refrigerator, FIG. 5 is a refrigerating cycle configuration diagram of the conventional refrigerator, and FIG. 6 is a diagram showing control during defrosting of the conventional refrigerator.

In FIGS. 4 and 5, the refrigerator 11 includes a housing 12, a door 13, legs 14 that support the housing 12, a lower machine room 15 provided at the bottom of the housing 12, and refrigeration arranged above the housing 12. It has a freezing room 18 arranged at the bottom of the room 17 and the housing 12. Further, as parts constituting the freezing cycle, a compressor 56 housed in the lower machine room 15, an evaporator 20 housed on the back side of the freezing room 18, and a main condenser 21 housed in the lower machine room 15 are included. Have. Further, it has a partition wall 22 for partitioning the lower machine room 15, a fan 23 attached to the partition wall 22 for air-cooling the main condenser 21, an evaporating dish 57 installed above the compressor 56, and a bottom plate 25 for the lower machine room 15. There is.

Further, a plurality of intake ports 26 provided on the bottom plate 25, a discharge port 27 provided on the back side of the lower machine room 15, and a communication air passage 28 connecting the discharge port 27 of the lower machine room 15 and the upper part of the housing 12 are provided. Have. Here, the lower machine room 15 is divided into two chambers by a partition wall 22, and the main condenser 21 is housed on the leeward side of the fan 23, and the compressor 56 and the evaporating dish 57 are housed on the leeward side.

Further, as a component constituting the refrigeration cycle, the dew-proof pipe 60 and the dew-proof pipe 60 located on the downstream side of the main condenser 21 and thermally coupled to the outer surface of the housing 12 around the opening of the freezing chamber 18 It is located on the downstream side and has a dryer 37 that dries the circulating refrigerant, and a throttle 62 that combines the dryer 37 and the evaporator 20 to reduce the pressure of the circulating refrigerant. Then, when the evaporator 20 is defrosted, it has a two-way valve 61 that closes the outlet of the dew-proof pipe 60 and a defrost heater (not shown) that heats the evaporator 20.

Further, the evaporator fan 50 that supplies the cold air generated by the evaporator 20 to the refrigerating chamber 17 and the freezing chamber 18, the freezing chamber damper 51 that shuts off the cold air supplied to the freezing chamber 18, and the cold air supplied to the refrigerating chamber 17 The temperature of the refrigerating chamber damper 52 to shut off, the duct 53 for supplying cold air to the refrigerating chamber 17, the FCC temperature sensor 54 for detecting the temperature of the refrigerating chamber 18, the PCC temperature sensor 55 for detecting the temperature of the refrigerating chamber 17, and the temperature of the evaporator 20. It has a DEF temperature sensor 58 to detect.

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

In the cooling stop state (hereinafter, this operation is referred to as "OFF mode") in which the fan 23, the compressor 56, and the evaporator fan 50 are all stopped, the temperature detected by the FCC temperature sensor 54 rises to a predetermined value of the FCC_ON temperature. Or, when the temperature detected by the PCC temperature sensor 55 rises to the predetermined PCC_ON temperature, the freezer compartment damper 51 is closed, the refrigerating chamber damper 52 is opened, and the compressor 56, the fan 23, and the evaporator fan 50 are opened. (Hereinafter, this operation is referred to as "PC cooling mode").

In the PC cooling mode, by driving the fan 23, the main condenser 21 side of the lower machine room 15 partitioned by the partition wall 22 becomes a negative pressure, and external air is sucked from a plurality of intake ports 26, and the compressor 56 and the evaporating dish are sucked. The pressure on the 57 side 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 condensed by leaving a part of the gas while exchanging heat with the outside air in the main condenser 21, and then supplied to the dew-proof pipe 60. The refrigerant passing through the dew-proof pipe 60 dissipates heat and condenses through the housing 12 while warming the opening of the freezing chamber 18. After passing through the two-way valve 61, the liquid refrigerant condensed by the dew-proof pipe 60 is dehydrated by the dryer 37, depressurized by the throttle 62, and evaporates by the evaporator 20 while exchanging heat with the air inside the refrigerator compartment 17. While cooling the refrigerating chamber 17, it is returned to the compressor 56 as a gaseous refrigerant.

During the PC cooling mode, when the temperature detected by the FCC temperature sensor 54 drops and rises to the predetermined value of FCC_OFF temperature and the temperature detected by the PCC temperature sensor 55 drops to the predetermined value of PCC_OFF temperature, the mode shifts to the OFF mode.

Further, during the PC cooling mode, when the temperature detected by the FCC temperature sensor 54 indicates a temperature higher than the predetermined value of the FCC_OFF temperature and the temperature detected by the PCC temperature sensor 55 drops to the predetermined value of the PCC_OFF temperature, the freezer damper. 51 is opened, the refrigerator damper 52 is closed, and the compressor 56, the fan 23, and the evaporator fan 50 are driven. Hereinafter, by operating the refrigeration cycle in the same manner as PC cooling, the air inside the freezing chamber 18 and the evaporator 20 exchange heat to cool the freezing chamber 18 (hereinafter, this operation is referred to as “FC cooling mode”). ..

During the FC cooling mode, when the temperature detected by the FCC temperature sensor 54 drops to the predetermined value of FCC_OFF temperature and the temperature detected by the PCC temperature sensor 55 indicates the predetermined value of PCC_ON temperature or higher, the mode shifts to the PC cooling mode. ..

Further, during the FC cooling mode, when the temperature detected by the FCC temperature sensor 54 drops to the FCC_OFF temperature of a predetermined value and the temperature detected by the PCC temperature sensor 55 indicates a temperature lower than the PCC_ON temperature of the predetermined value, the OFF mode is used. Transition to.

Here, the control at the time of defrosting of the conventional refrigerator will be described with reference to FIG.

When the cumulative operating time of the compressor 56 reaches a predetermined time, the mode shifts to the defrosting mode in which the frost formation of the evaporator 20 is heated and melted. In the defrosting mode section p, first, in order to suppress the temperature rise of the freezing chamber 18, the freezing chamber 18 is cooled for a predetermined time in the same manner as in the FC cooling mode. Next, in the section q, the refrigerant staying in the dryer 37 and the evaporator 20 is recovered to the main condenser 21 and the dew-proof pipe 60 by closing the two-way valve 61 while operating the compressor 56. Then, in the 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 separates the high-pressure side and the low-pressure side inside the compressor 56 by stopping the compressor 56. By flowing the recovered high-pressure refrigerant back into the evaporator 20, the evaporator 20 is heated by using the high-pressure refrigerant further heated by the waste heat of the compressor 56. Then, in the section s, the defrost heater (not shown) attached to the evaporator 20 is energized to complete the defrosting. Then, in the section t, the two-way valve 61 is opened to equalize the pressure in the refrigeration cycle, and the normal operation is restarted from the section u.

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

Japanese Unexamined Patent Publication No. 4-194564

However, in the conventional refrigerator configuration, by stopping the compressor 56, the recovered high-pressure refrigerant flows back to the evaporator 20 via the compressor 56, so that the waste heat of the compressor 56 is used by using the high-pressure refrigerant. Can be used to heat the compressor 20 by collecting the refrigerant. On the other hand, the refrigerant flowing into the compressor 20 uses the backflow due to the leakage of the seal portion such as the valve that separates the high pressure side and the low pressure side inside the compressor 56. The amount is reduced, which causes the power amount of the defrosting heater to be insufficiently reduced.

Therefore, when the recovered high-pressure refrigerant is used for defrosting the evaporator 20, it has been an issue to maintain the flow path resistance when the high-pressure refrigerant flows into the evaporator 20.

The present invention solves the conventional problems, and an object of the present invention is to suppress fluctuations in flow path resistance when the recovered high-pressure refrigerant is used for defrosting the evaporator 20.

In order to solve the conventional problems, in the refrigerator of the present invention, in addition to the evaporator, the refrigerant staying in the dew-proof pipe heat-bonded to the vicinity of the opening of the freezer is also recovered at the same time and recovered in the main condenser. At the same time, when the recovered high-pressure refrigerant is used for defrosting the evaporator, it is characterized in that it is supplied to the evaporator via a bypass circuit.

As a result, when the recovered high-pressure refrigerant is used for defrosting the evaporator, the amount of electric power of the defrost heater can be reduced by suppressing the fluctuation of the flow path resistance.

In the refrigerator of the present invention, the amount of electric power of the defrost heater can be reduced by collecting the refrigerant in the refrigeration cycle in the main condenser and using it for heating the evaporator, thereby saving energy in the refrigerator. Can be done.

Longitudinal sectional view of the refrigerator according to the first embodiment of the present invention. Cycle configuration diagram of the refrigerator according to the first embodiment of the present invention The figure which showed the control at the time of defrosting of the refrigerator in Embodiment 1 of this invention. Longitudinal section of a conventional refrigerator Cycle configuration diagram of a conventional refrigerator The figure which showed the operation of the flow path switching valve of the conventional refrigerator

The first 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 and a flow path switching valve downstream of the flow path switching valve. By having a dew-proof pipe connected to the side and a bypass connected to the downstream side of the flow path switching valve in parallel with the dew-proof pipe, the flow path switching valve is fully closed while the compressor is in operation. After recovering the retained refrigerant in the evaporator and the dew-proof pipe, the recovered refrigerant is supplied to the evaporator by stopping the compressor and opening the flow path switching valve to the bypass side. The defrosting heater is energized after a predetermined time.

As a result, when the refrigerant in the refrigeration cycle is recovered in the main condenser and used for heating the evaporator, the fluctuation of the flow path resistance is suppressed, thereby stably reducing the electric energy of the defrost heater. It is possible to save energy in the refrigerator.

The second invention has, in the first invention, a flow path resistance connected between the outlet of the bypass and the outlet of the dew-proof pipe, and the flow path switching valve is opened to the bypass side to provide a high-pressure refrigerant. When defrosting the evaporator while supplying the evaporator, the pressure in the bypass is maintained at a higher pressure than in the dew-proof pipe.

As a result, when the refrigerant in the refrigeration cycle is recovered in the main condenser and used for heating the evaporator, fluctuations in flow path resistance and high-pressure pressure are suppressed, thereby stabilizing the electric energy of the defrost heater. It is possible to reduce the energy consumption of the refrigerator.

The third invention is the resistance provided between the heat exchange section that thermally couples a part of the bypass path and the housing, and the heat exchange section and the flow path switching valve in either the first or second invention. When the evaporator is defrosted while supplying the high-pressure refrigerant to the evaporator by opening the flow path switching valve to the bypass side, the high-pressure refrigerant is heated by utilizing the heat storage of the housing. It is a thing.

As a result, when the refrigerant in the refrigeration cycle is recovered in the main condenser and used for heating the evaporator, the temperature of the refrigerant is lowered from that of the main condenser by passing through a resistor, and then the casing close to the ambient temperature. By recovering the heat storage of the body to increase the enthalpy of the refrigerant and then using it for heating the evaporator, the electric energy of the defrost heater can be further reduced, and the energy saving of the refrigerator can be achieved.

The fourth invention is the third invention in which a heat exchange portion for heat-bonding a part of the bypass path and the housing is provided on the back surface of the housing.

As a result, when the refrigerant in the refrigeration cycle is collected in the main condenser and used for heating the evaporator, the temperature of the refrigerant is lowered from that of the main condenser by passing through a resistor, and then the housing and the back surface are used. By exchanging heat with the wall in contact with the surrounding air and the surrounding air, the heat storage in the surroundings including the housing close to the ambient temperature is recovered to increase the enthalpy of the refrigerant, and then it is used to heat the evaporator to heat the defrost heater. The amount of electric power can be further reduced, and the energy saving of the refrigerator can be achieved.

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

(Embodiment 1)
FIG. 1 is a vertical cross-sectional view of the 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. It is a figure shown.

In FIGS. 1 and 2, the refrigerator 11 includes a housing 12, a door 13, legs 14 that support the housing 12, a lower machine room 15 provided at the lower part of the housing 12, and an upper portion provided at the upper part of the housing 12. It has a machine room 16, a refrigerating room 17 arranged in the upper part of the housing 12, and a freezing room 18 arranged in the lower part of the housing 12. The upper machine room 16 is composed of a base panel 16a, a cover panel 16b, and a reinforcing member 16c. Further, as parts constituting the freezing cycle, a compressor 19 housed in the upper machine room 16, an evaporator 20 housed on the back side of the freezing room 18, and a main condenser 21 housed in the lower machine room 15. have. Further, it has a partition wall 22 for partitioning the lower machine room 15, a fan 23 attached to the partition wall 22 for air-cooling the main condenser 21, an evaporating dish 24 installed on the leeward side of the partition wall 22, and a bottom plate 25 for the lower machine room 15. There is.

Here, the compressor 19 is a variable speed compressor, and uses six rotation speeds selected from 20 to 80 rps. This is to adjust the refrigerating capacity by switching the rotation speed of the compressor 19 in 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 starting, and increases in speed as the operation time for cooling the refrigerating chamber 17 or the freezing chamber 18 becomes longer. This is because the most efficient low speed is mainly used, and a relatively high rotation speed suitable for an increase in the load of the refrigerating chamber 17 or the freezing chamber 18 due to a high outside temperature or opening / closing of a door is used. .. 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 time of starting the PC cooling mode having a high evaporation temperature and a relatively large refrigerating capacity is higher than that of the FC cooling mode. It may be set low. Further, the refrigerating capacity may be adjusted while decelerating the compressor 19 as the temperature of the refrigerating chamber 17 or the freezing chamber 18 decreases.

Further, it has a plurality of intake ports 26 provided on the bottom plate 25, an exhaust port 27 provided on the back side of the lower machine room 15, and a communication air passage 28 connecting the discharge port 27 of the lower machine room 15 and the upper machine room 16. are doing. Here, the lower machine room 15 is divided into two chambers by a partition wall 22, and the main condenser 21 is housed on the leeward side of the fan 23 and the evaporating dish 24 is housed on the leeward side.

Further, as a component constituting the refrigeration cycle, a flow path switching valve 40 located on the downstream side of the main condenser 21 and drying the circulating refrigerant, and on the downstream side of the dryer 38 to control the flow of the refrigerant. A throttle that connects the dew-proof pipe 41, which is located on the downstream side of the flow path switching valve 40 and is heat-bonded to the outer surface of the housing 12 around the opening of the freezer chamber 18, and the dew-proof pipe 41 and the evaporator 20. Flow path resistance) 42, bypass 43 connecting the downstream side of the flow path switching valve 40 and the evaporator 20 in parallel with the dew-proof pipe 41, heat exchange unit 44 that thermally couples with the housing 12 in the path of the bypass 43, heat It has a resistor 45 that is upstream of the exchange section 44 and reduces the pressure of the refrigerant passing through the path of the bypass 43. Here, the heat exchange portion 44 is attached to the back surface of the housing 12 with aluminum foil tape, and the peripheral structure (not shown) in which the housing 12 and the back surface of the housing 12 are in contact with each other via the back surface of the housing 12. ) Or the heat storage of the ambient air (not shown) can be recovered. This is because when the refrigerant in the main condenser 21 maintained at a substantially outside air temperature passes through the bypass 43, the pressure is reduced by the resistor 45 to be lower than the outside air temperature, so that the housing is at a substantially outside air temperature. A temperature difference occurs between the peripheral structure (not shown) or the ambient air (not shown) in contact with the back surface of the housing 12 and the housing 12, and the heat storage can be recovered by the heat capacity thereof. Further, the flow path switching valve 40 can control the opening and closing of the flow of the refrigerant independently of the dew-proof pipe 40 and the bypass 43. Normally, the flow path switching valve 40 opens the flow path from the main condenser 21 to the dew-proof pipe 40 and keeps the flow path from the main condenser 21 to the bypass 43 closed, and defrosting will be described later. The flow path is opened and closed only when.

Further, the evaporator fan 30 that supplies the cold air generated by the evaporator 20 to the refrigerating chamber 17 and the freezing chamber 18, the freezing chamber damper 31 that shuts off the cold air supplied to the freezing chamber 18, and the cold air supplied to the refrigerating chamber 17 The temperature of the refrigerating chamber damper 32 to shut off, the duct 33 for supplying cold air to the refrigerating chamber 17, the FCC temperature sensor 34 for detecting the temperature of the refrigerating chamber 18, the PCC temperature sensor 35 for detecting the temperature of the refrigerating chamber 17, and the temperature of the evaporator 20. It has a DEF temperature sensor 36 for detecting. Here, the duct 33 is formed along the wall surface where the refrigerating chamber 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 refrigerating chamber, and most of the cold air is the upper machine. After the chamber 16 passes through the adjacent wall surface while cooling, it is discharged from the upper part of the refrigerating chamber 17.

The operation of the refrigerator of the first embodiment configured as described above will be described below, but the same components as those of the conventional example are designated by the same reference numerals, and detailed description thereof will be omitted.

In the cooling stop state (hereinafter, this operation is referred to as "OFF mode") in which the fan 23, the compressor 19, and the evaporator fan 30 are all stopped, the temperature detected by the FCC temperature sensor 34 rises to a predetermined value of the FCC_ON temperature. Or, when the temperature detected by the PCC temperature sensor 35 rises to the predetermined PCC_ON temperature, the freezer compartment damper 31 is closed, the refrigerating chamber damper 32 is opened, and the compressor 19, fan 23, and evaporator fan 30 are closed. (Hereinafter, this operation is referred to as "PC cooling mode").

In the PC cooling mode, by driving the fan 23, the main condenser 21 side of the lower machine room 15 partitioned by the partition wall 22 becomes a negative pressure, external air is sucked from a plurality of intake ports 26, and the evaporating dish 24 side has a positive pressure. Next, 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 by leaving a part of the gas while exchanging heat with the outside air in the main condenser 21, and then the moisture is removed by the dryer 38 and prevented via the flow path switching valve 40. It is supplied to the dew pipe 41. The refrigerant that has passed through the dew-proof pipe 41 dissipates heat and condenses through the housing 12 while warming the opening of the freezer chamber 18, and then is depressurized by the throttle (flow path resistance) 42 and evaporated by the evaporator 20. While exchanging heat with the air inside the refrigerator chamber 17 to cool the refrigerator chamber 17, it returns to the compressor 19 as a gaseous refrigerant.

During the PC cooling mode, when the temperature detected by the FCC temperature sensor 34 drops and rises to the predetermined value of FCC_OFF temperature and the temperature detected by the PCC temperature sensor 35 drops to the predetermined value of PCC_OFF temperature, the mode shifts to the OFF mode.

Further, during the PC cooling mode, when the temperature detected by the FCC temperature sensor 34 indicates a temperature higher than the predetermined value of the FCC_OFF temperature and the temperature detected by the PCC temperature sensor 35 drops to the predetermined value of the PCC_OFF temperature, the freezer damper. 30 is opened, the refrigerator damper 32 is closed, and the compressor 19, the fan 23, and the evaporator fan 30 are driven. Hereinafter, by operating the refrigeration cycle in the same manner as PC cooling, the air inside the freezing chamber 18 and the evaporator 20 exchange heat to cool the freezing chamber 18 (hereinafter, this operation is referred to as “FC cooling mode”). ..

During the FC cooling mode, when the temperature detected by the FCC temperature sensor 34 drops to the predetermined value of FCC_OFF temperature and the temperature detected by the PCC temperature sensor 35 indicates the predetermined value of PCC_ON temperature or higher, the mode shifts to the PC cooling mode. ..

Further, during the FC cooling mode, when the temperature detected by the FCC temperature sensor 34 drops to the FCC_OFF temperature of a 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, the OFF mode is used. Transition to.

Here, the control at the time of defrosting the refrigerator of the first embodiment will be described.

In FIG. 3, 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 43 is closed. means. Further, the state "closed / opened" 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 43 is opened. To do. The state "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 43 is closed.

When the cumulative operating time of the compressor 19 reaches a predetermined time, the mode shifts to the defrosting mode in which the frost formation of the evaporator 20 is heated and melted. In the defrosting mode section a, first, in order to suppress the temperature rise of the freezing chamber 18, the freezing chamber 18 is cooled for a predetermined time in the same manner as in the FC cooling mode. Next, in section b, by fully closing the flow path switching valve 40 while operating the compressor 19, the flow path from the main condenser 21 to the dew-proof pipe 41 and the bypass 43 is closed together to block the dew-proof pipe. The refrigerant staying in the 41, the evaporator 20, and the bypass 43 is collected in the main condenser 21. Then, in the 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 43, so that the main condensation is performed via the resistor 45 and the bypass 43. The high-pressure refrigerant recovered in the vessel 21 is supplied to the evaporator 20. At this time, the heat exchanged portion 44 is passed by the heat storage of the peripheral structure (not shown) or the ambient air (not shown) in which the housing 12 and the back surface of the housing 12 are in contact with each other via the back surface of the housing 12. The refrigerant is heated, and the dryness of the refrigerant is increased. This is because when the high-pressure refrigerant is recovered in the main condenser 21 in the section b, it dissipates heat to the outside air and most of it condenses. Therefore, as compared with the case where the high-pressure refrigerant is supplied to the evaporator 20 without being heated by the heat exchange unit 44 in the section c, the amount of heat due to the latent heat of condensation is evaporated in addition to the sensible heat of the high-pressure refrigerant maintained at the outside air temperature. It can be added to the vessel 20. Next, in section d, a defrost heater (not shown) attached to the evaporator 20 is energized to complete defrosting. The completion of defrosting is determined when the DEF temperature sensor 36 reaches a predetermined temperature. Then, in the section e, the flow path switching valve 40 is switched to block the flow path from the main condenser 21 to the bypass 43, and the flow path from the main condenser 21 to the dew-proof pipe 41 is opened to enter the refrigeration cycle. Is equalized, and normal operation is restarted from the section f.

As described above, the refrigerator of the first embodiment collects the refrigerant staying in the evaporator 20 and the dew-proof pipe 41 at the time of defrosting in the main condenser 21, and heat-bonds the refrigerant to the compressor 19 in the heat exchange unit 44. By supplying a high-pressure refrigerant to the evaporator 20 via the bypass 43 having the above to heat the evaporator 20, the amount of power of the defrost heater (not shown) can be reduced, and the energy saving of the refrigerator can be reduced. Can be planned.

In the refrigerator of the first embodiment, the main condenser 21 is a forced air-cooled type condenser, but a dew-proof pipe that is heat-bonded to the side surface or the back surface of the housing 12 may be used. Unlike the dew-proof pipe that is heat-bonded to the periphery of the openings of the refrigerating chamber 17 and the freezing chamber 18, the dew-proof pipe that is heat-bonded to the side surface and the back surface of the housing 12 is maintained near the outside air temperature even when the compressor 19 is stopped. Therefore, the same effect can be expected even if it is used as the main condenser 21.

In the refrigerator of the first embodiment, the heat exchange unit 44 is provided on the back surface of the housing 12, and the heat storage contained in the peripheral structure (not shown) or the ambient air (not shown) in contact with the back surface of the housing 12. However, even if the heat exchange unit 44 is provided on the side surface or the top surface of the housing 12, the same effect can be expected in that the heat storage of the housing 12 is used. Further, in the refrigerator of the first embodiment, the heat exchange unit 44 is provided thermally independently of the main condenser 21, but a part of the main condenser 21 is thermally coupled to the side surface or the back surface of the housing 12. It may be replaced with a dew-proof pipe and may be thermally coupled to the heat exchange unit 44. By heat-bonding a part of the main condenser 21 and the heat exchange unit 44, the heat exchange unit 44, which becomes lower than the outside air temperature at the time of defrosting, can be quickly heated at the start of normal operation. It is possible to suppress the occurrence of dew condensation on 44 and the peripheral portion.

In the refrigerator of the first embodiment, the compressor 19 is stopped by directly supplying the high-pressure refrigerant to the evaporator 20 without passing through the dew-proof pipe 41 and the throttle (flow path resistance) 42 at the time of defrosting. Although it was avoided that the temperature of the high-pressure refrigerant was lowered due to the influence of the dew-proof pipe 41 which became lower than the main condenser 21 at the time of the defrosting, the temperature of the evaporator 20 was higher than that of the dew-proof pipe 41 due to the progress of defrosting. Then, the high-pressure refrigerant may flow back from the evaporator 20 to the dew-proof pipe 41 through the throttle (flow path resistance) 42, so that the backflow is caused from the outlet of the dew-proof pipe 41 into the path of the inlet of the evaporator 20. A check valve or a two-way valve for prevention may be provided.

As described above, in the refrigerator according to the present invention, the refrigerant staying in the evaporator and the dew-proof pipe is collected 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 by using the heating energy, it can be applied to other refrigerating and refrigerating applied products such as commercial refrigerators.

11 Refrigerator 12 Housing 15 Lower machine room 16 Upper machine room 16a Base panel 16b Cover panel 16c Reinforcing member 19 Compressor 20 Evaporator 30 Evaporator fan 31 Freezer room damper 32 Refrigerator room damper 33 Duct 34 FCC temperature sensor 35 PCC temperature sensor 40 Flow path switching valve 41 Dew-proof pipe 42 Throttle (flow path resistance)
43 Bypass 44 Heat Exchanger 45 Resistor

Claims (4)

A refrigeration cycle having at least a compressor, an evaporator, a main condenser, and a dew-proof pipe is provided, and a flow path switching valve connected to the downstream side of the main condenser and dew-proof connected to the downstream side of the flow path switching valve. It has a pipe and a bypass connected to the downstream side of the flow path switching valve in parallel with the dew-proof pipe, and by fully closing the flow path switching valve while operating the compressor, the evaporator and the flow prevention are prevented. After recovering the stagnant refrigerant in the dew pipe, the compressor is stopped and the flow path switching valve is opened to the bypass side to defrost the recovered refrigerant by supplying it to the evaporator. A refrigerator characterized in that the defrosting heater is energized after a predetermined time. It has a flow path resistance connected between the outlet of the bypass and the outlet of the dew-proof pipe, and defrosts the evaporator while opening the flow path switching valve to the bypass side and supplying a high-pressure refrigerant to the evaporator. The refrigerator according to claim 1, wherein the pressure in the bypass is maintained at a pressure higher than that in the dew-proof pipe. It has a heat exchange section that thermally couples a part of the bypass and the housing, and a resistor provided between the heat exchange section and the flow path switching valve, and opens the flow path switching valve to the bypass side. The invention according to claim 1 or 2, wherein when the evaporator is defrosted while supplying the high-pressure refrigerant to the evaporator, the high-pressure refrigerant is heated by utilizing the heat storage of the housing. refrigerator. The refrigerator according to claim 3, wherein the heat exchange unit is provided on the back surface of the housing.

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