JP2015094536A - Refrigerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate loss of recovering a refrigerant staying in a dew-proofing pipe when lowering temperature by intermittently using the dew-proofing pipe connected to a downstream side of a main condenser.SOLUTION: A refrigerator includes a refrigeration cycle at least including a compressor 19, an evaporator 20, a main condenser 21, a dew-proofing pipe 41, and a throttle 44. The refrigerator includes: the main condenser 21; the dew-proofing pipe 41 located on a downstream side of the main condenser 21; and a resistance switching mechanism which is connected between the main condenser 21 and the dew-proofing pipe 41 and which changes flow passage resistance of a refrigerant. When the refrigeration cycle operates under a normal condition, by increasing the resistance of the resistance switching mechanism, the temperature of the dew-proofing pipe 41 can be made to be lower than that of the main condenser 21. Thus, reduction in an amount of invasion heat due to the dew-proofing pipe 41 is achieved, a recovery operation of the refrigerant staying in the dew-proofing pipe 41 can be eliminated, and an amount of power consumption of the refrigerator can be reduced.

Description

  The present invention relates to a refrigerator that reduces a heat load caused by a dew-proof pipe by operating a refrigeration cycle while intermittently using the dew-proof pipe.

  From the viewpoint of energy saving, there are refrigerators for household use that reduce the heat load caused by the dew-proof pipe by operating the refrigeration cycle while intermittently using the dew-proof pipe. This is because some dew-proof pipes are intermittently used under light load conditions where the temperature and humidity around the refrigerator are relatively low, and the temperature of the dew-proof pipe and its surroundings is lowered to the extent that the surface of the housing does not sweat. In this way, the amount of intrusion heat transferred to the inside of the casing is reduced, and as a result, the heat load of the refrigerator is reduced to save energy.

  Furthermore, a configuration has been proposed in which a plurality of dew-proof pipes that are temporarily unused are connected to an evaporator via capillary tubes, respectively (see, for example, Patent Document 1). This is to keep the inside of the dew protection pipe, which is temporarily not used, at a low pressure, thereby recovering the refrigerant staying inside during use, and as a result, avoiding a decrease in the circulation rate of the refrigerant Thus, a decrease in the refrigeration cycle efficiency is suppressed.

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

  FIG. 8 is a longitudinal sectional view of a conventional refrigerator, FIG. 9 is a configuration diagram of a refrigeration cycle of the conventional refrigerator, and FIG. 10 is a diagram showing the operation of the flow path switching valve of the conventional refrigerator.

  8 and 9, the refrigerator 11 includes a housing 12, a door 13, legs 14 that support the housing 12, a lower machine room 15 provided in the lower part of the housing 12, and a refrigerator that is disposed in the upper part of the housing 12. It has the freezer compartment 18 arrange | positioned at the chamber 17 and the lower part of the housing | casing 12. FIG. 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 21 housed in the lower machine room 15 are provided. Have. Further, it has a partition wall 22 that partitions the lower machine chamber 15, a fan 23 that is attached to the partition wall 22 to air-cool the main condenser 21, an evaporating dish 57 installed on the top of the compressor 56, and a bottom plate 25 of the lower machine chamber 15. Yes.

  Also, a plurality of air intakes 26 provided in 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 exhaust port 27 of the lower machine room 15 and the upper part of the housing 12 are provided. Have. Here, the lower machine chamber 15 is divided into two chambers by the partition wall 22, and the main condenser 21 is housed on the windward side of the fan 23, and the compressor 56 and the evaporating dish 57 are housed on the leeward side.

  Further, as the components constituting the refrigeration cycle, the dew-proof pipe 60 and the dew-proof pipe 60 which are located on the downstream side of the main condenser 21 and are thermally coupled to the outer surface of the housing 12 around the opening of the freezer compartment 18. It is located downstream, and has a dryer 37 that dries the circulating refrigerant, and a throttle 44 that combines the dryer 37 and the evaporator 20 and depressurizes the circulating refrigerant. Further, in order to temporarily disable the dew proof pipe 60, the dew proof pipe 60 is connected between the flow path switching valve 40, the flow path switching valve 61 and the evaporator 20, which branches upstream of the dew proof pipe 60. A bypass 46, a dryer 39, and an aperture 47 are connected in parallel.

In addition, an evaporator fan 50 that supplies cold air generated in the evaporator 20 to the refrigerator compartment 17 and the freezer compartment 18, a freezer damper 51 that shuts off the cold air supplied to the freezer compartment 18, and cold air supplied to the refrigerator compartment 17 The refrigerator compartment damper 52 to be shut off, the duct 53 for supplying cold air to the refrigerator compartment 17, the FCC temperature sensor 54 for detecting the temperature of the freezer compartment 18, the PCC temperature sensor 55 for detecting the temperature of the refrigerator compartment 17, and the temperature of the evaporator 20 are set. It has a DEF temperature sensor 58 for detection.

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

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

  In the PC cooling mode, when the fan 23 is driven, the main condenser 21 side of the lower machine chamber 15 partitioned by the partition wall 22 has a negative pressure, and external air is sucked from the plurality of air inlets 26, and the compressor 56 and the evaporating dish 57 side becomes a positive pressure, and the air in the lower machine room 15 is discharged to the outside through the plurality of discharge ports 27.

  On the other hand, the refrigerant discharged from the compressor 56 is condensed while leaving a part of the gas while exchanging heat with the outside air in the main condenser 21 and then supplied to the dewproof pipe 60. The refrigerant that has passed through the dewproof pipe 60 dissipates heat through the housing 12 and condenses while warming the opening of the freezer compartment 18. The liquid refrigerant that has passed through the dew-proof pipe 60 is dehydrated by the dryer 37, depressurized by the throttle 44, and is evaporated by the evaporator 20 while exchanging heat with the air in the refrigerator compartment 17 to cool the refrigerator compartment 17. Then, it returns to the compressor 56 as a gaseous refrigerant.

  Here, the operation of the flow path switching valve 61 will be described.

  In FIG. 10, p1, p2, and p3 indicate operating sections of the refrigeration cycle, and q1 and q2 indicate stop sections of the refrigeration cycle. In each of the sections p1, p2, and p3, the compressor 56 is operated, and the flow path switching valve 61 is switched to intermittently use the dew-proof pipe 60. Moreover, the representative temperature of the opening part of the freezer compartment 18 heated by the dewproof pipe 60 is shown as the surface temperature of the housing. The operation “open / close” of the flow path switching valve 61 opens the flow path on the dew prevention pipe 60 side and closes the flow path on the bypass 46 side, thereby allowing the refrigerant in the main condenser 21 to flow through the dew prevention pipe 60. Similarly, “closed open” closes the flow path on the dew-proof pipe 60 side and opens the flow path on the bypass 46 side, thereby allowing the refrigerant in the main condenser 21 to flow into the bypass 46 and the dew-proof pipe 60. The refrigerant staying inside is collected into the evaporator 20. “Closed” means that the flow path on the dewproof pipe 60 side is closed and the flow path on the bypass 46 side is closed, so that the refrigerant of the main condenser 21 in the sections q1 and q2 where the compressor 56 stops. Is prevented from flowing into the evaporator 20 due to a pressure difference.

  As described above, in the conventional refrigerator, the surface temperature of the casing heated by the dew prevention pipe 60 is lowered by alternately switching the dew prevention pipe 60 and the bypass 46 during the operation of the refrigeration cycle, thereby reducing the amount of intrusion heat. . At this time, by fixing the time r during which the dew proof pipe 60 is used and the time s during which the dew proof pipe 60 is not used, by performing switching several times in one section, the non-use ratio of the dew proof pipe 60 is controlled, and The average value of the surface temperature of the casing heated by 60 is adjusted to a predetermined level. For example, when the humidity is high by adjusting the ratio between the time r when the dew-proof pipe 60 is used and the time s when it is not used based on the humidity around the refrigerator detected by a humidity sensor (not shown). By increasing the time r for using the dew-proof pipe 60 to increase the surface temperature of the housing, and when the humidity is low, the time r for using the dew-proof pipe 60 is decreased to lower the surface temperature of the housing to prevent sweating. And energy saving.

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

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

  During the FC cooling mode, 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 indicates the PCC_ON temperature of the predetermined value or more, the PC cooling mode is entered. .

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

  By the operation described above, by alternately switching between the dew-proof pipe 60 and the bypass 46 during the operation of the refrigeration cycle, the surface temperature of the casing warmed by the dew-proof pipe 60 is lowered to reduce the amount of intrusion heat. As a result, it is possible to save energy while maintaining perspiration prevention performance.

Japanese Patent Laid-Open No. 8-189533

  However, in the conventional refrigerator configuration, when the dew-proof pipe 60 and the bypass 46 are alternately switched, the refrigerant is accumulated in the dew-proof pipe 60 by switching to the bypass 46 after the dew-proof pipe 60 is used. In doing so, the refrigerant evaporated inside the dew-proof pipe 60 flows into the evaporator 20, thereby reducing the efficiency of the refrigeration cycle and increasing the power consumption of the refrigerator.

  Accordingly, it has been a problem to reduce the number of times of switching between the dew-proof pipe 60 and the bypass 46 and to suppress fluctuations in the amount of refrigerant that stays inside the dew-proof pipe 60 during use.

  The present invention solves the conventional problem, and by adjusting the temperature of the dew prevention pipe when operating the refrigeration cycle, the fluctuation of the amount of refrigerant staying in the dew prevention pipe is suppressed, and the dew prevention pipe The purpose is to eliminate the operation of collecting the refrigerant inside.

  In order to solve the conventional problems, the refrigerator of the present invention is characterized in that the temperature of the dew prevention pipe is lowered than that of the main condenser by a resistance switching mechanism provided between the main condenser and the dew prevention pipe. Is.

As a result, it is possible to reduce the amount of intrusion heat caused by the dew prevention pipe and to eliminate the operation of collecting the refrigerant staying in the dew prevention pipe.

  The refrigerator of the present invention can reduce the amount of intrusion heat caused by the dew prevention pipe by reducing the temperature of the dew prevention pipe from that of the main condenser, and can eliminate the recovery operation of the refrigerant staying in the dew prevention pipe. This can reduce the power consumption of the refrigerator.

  In addition, by combining the flow resistance of the resistance switching mechanism provided between the main condenser and the dew-proof pipe and the flow resistance of the throttle mechanism of the refrigeration cycle composed of capillary tubes, the compressor is driven at a low speed. Since the loss due to insufficient throttling of the refrigeration cycle that occurs during the operation can be suppressed, further energy saving of the refrigerator can be realized by improving the refrigeration cycle efficiency during normal operation.

The longitudinal cross-sectional view of the refrigerator in Embodiment 1 of this invention Cycle configuration diagram of refrigerator in Embodiment 1 of the present invention The figure which showed operation | movement of the flow-path switching valve of the refrigerator in Embodiment 1 of this invention Cycle configuration diagram of refrigerator in embodiment 2 of the present invention The figure which showed operation | movement of the flow-path switching valve of the refrigerator in Embodiment 2 of this invention Cycle configuration diagram of refrigerator in embodiment 3 of the present invention The figure which showed operation | movement of the flow-path switching valve of the refrigerator in Embodiment 3 of this invention Vertical 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, a dew proof pipe, and a throttle, the main condenser, a dew proof pipe on the downstream side of the main condenser, It has a resistance switching mechanism that is connected between the main condenser and the dew-proof pipe and that changes the flow path resistance of the refrigerant.

  As a result, when the refrigeration cycle is operated under normal conditions, the resistance of the resistance switching mechanism is increased so that the temperature of the dew proof pipe can be made lower than that of the main condenser. While reducing the amount of intrusion heat, it is possible to eliminate the operation of collecting the refrigerant staying in the dew-proof pipe, and the power consumption of the refrigerator can be reduced. Loss due to insufficient throttling of the refrigeration cycle, especially when the compressor is driven at low speed, by combining the flow resistance of the resistance switching mechanism provided between the main condenser and the dew proof pipe and the flow resistance of the throttle. Therefore, further energy saving of the refrigerator can be realized by improving the refrigeration cycle efficiency during normal operation.

  According to a second invention, in the first invention, there is provided a resistance switching mechanism comprising a flow path switching valve that switches the flow path cross-sectional area steplessly using a needle valve, and is provided between the main condenser and the dew-proof pipe. The resistance switching mechanism is connected.

  As a result, the flow path configuration can be simplified and the space can be saved, and the flow path resistance can be adjusted to the optimum according to the operating conditions of the refrigeration cycle.

According to a third invention, in the first invention, the intermediate resistor comprises a small-diameter pipe, a bypass pipe that bypasses the intermediate resistor, and a flow path switching valve that switches the intermediate resistor and the bypass pipe. It has a resistance switching mechanism, and the resistance switching mechanism is connected between the main condenser and the dew-proof pipe.

  As a result, the temperature of the refrigerant passing through the flow path switching valve can be substantially equal to that of the main condenser, so that dew condensation on the flow path switching valve, which is a mechanical component, can be suppressed. In addition, since the flow path resistance is formed using a small-diameter tube, the flow path cross-sectional area can be increased as compared with the case where the flow path resistance is formed using a needle valve or the like. Thus, generation of refrigerant flow noise can be suppressed.

  The fourth invention is characterized in that, in the third invention, an intermediate resistor comprising a thin tube having an inner diameter of 0.8 mm or more is provided.

  Thereby, it is possible to suppress the refrigerant flow noise when the refrigerant at the outlet of the main condenser having a high dryness and a high flow velocity passes. The throttle of the refrigeration cycle of the refrigerator is usually constituted by a capillary tube made of a thin tube having an inner diameter of 0.5 to 0.8 mm, and the inner diameter of the intermediate resistor having a large dryness is larger than that of the refrigeration cycle. It is desirable to select an inner diameter.

  According to a fifth invention, in any one of the first to fourth inventions, when the refrigeration cycle is operated under normal conditions, the resistance of the resistance switching mechanism is increased so that the temperature of the dew-proof pipe is higher than that of the main condenser. It is also characterized by lowering.

  Accordingly, the amount of intrusion heat caused by the dew-proof pipe can be reduced, and the refrigeration cycle efficiency can be improved by combining the flow path resistance of the resistance switching mechanism and the flow path resistance of the throttle. In addition, since the temperature of the main condenser at the time of normal operation of a refrigerator is usually about 3-6 degreeC higher than ambient temperature, in order to adjust the temperature of a dew condensation pipe to ambient temperature-ambient dew point temperature, a dew prevention pipe It is desirable to lower the temperature of the main condenser by about 3 to 9 ° C. Also, if the temperature of the dew-proof pipe is lowered by 10 ° C or more from the main condenser, the refrigerant circulation rate of the refrigeration cycle is reduced due to the combination of the flow path resistance of the resistance switching mechanism and the flow path resistance of the throttle, resulting in insufficient refrigeration capacity This raises concerns.

  A sixth invention is the invention according to any one of the first to fifth inventions, wherein the resistance switching mechanism, the dew proof pipe and the throttle are connected in parallel, and the bypass pipe bypassing the resistance switching mechanism and the dew proof pipe, The bypass pipe and the evaporator are connected, the second throttle having a flow path resistance, the resistance switching mechanism and a flow path switching valve for switching the flow path of the bypass pipe, and the bypass pipe is connected at the start of the refrigeration cycle. It is characterized by being used.

  Thereby, particularly when the ambient temperature is low, the start-up characteristics of the refrigeration cycle can be improved by using a bypass pipe having a smaller internal volume than the dew-proof pipe. Normally, if the resistance switching mechanism is closed when the refrigeration cycle is stopped, the refrigerant in the dew proof pipe and the bypass pipe flows out due to a pressure difference. Therefore, when the refrigeration cycle starts, the inlet side of the throttle becomes insufficient and the refrigerant circulation rate rises. There is a concern that will be delayed. Therefore, by using a bypass pipe having a smaller internal volume than the dew-proof pipe at the start of the refrigeration cycle, it is possible to suppress a refrigerant shortage on the inlet side of the throttle and improve the rising characteristics of the refrigeration cycle.

  According to a seventh invention, in any one of the first to sixth inventions, an upper machine room and a lower machine room are provided, a compressor is disposed in the upper machine room, and a resistance switching mechanism is provided in the lower machine room. It is characterized by arranging.

  Thereby, the noise of the refrigerator can be reduced by suppressing the resonance between the connecting pipe of the resistance switching mechanism and the compressor.

According to an eighth invention, in the seventh invention, a confluence of a plurality of dew prevention pipes is disposed in the upper machine room, and a flow direction of the dew prevention pipe is set substantially upward.

  This makes it possible to reduce the amount of refrigerant staying in the dew prevention pipe by setting the flow direction of the plurality of dew prevention pipes to one direction, and to suppress the efficiency reduction of the refrigeration cycle accompanying the decrease in the amount of circulating refrigerant. it can.

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

(Embodiment 1)
1 is a longitudinal sectional view of a refrigerator according to Embodiment 1 of the present invention, FIG. 2 is a cycle configuration diagram of the refrigerator according to Embodiment 1 of the present invention, and FIG. 3 is an operation of a flow path switching valve of the refrigerator according to Embodiment 1. FIG.

  In FIG. 1 and FIG. 2, the refrigerator 11 includes a housing 12, a door 13, legs 14 that support the housing 12, a lower machine room 15 provided in the lower portion of the housing 12, and an upper portion provided in the upper portion of the housing 12. It has a machine room 16, a refrigeration room 17 disposed at the upper part of the casing 12, and a freezing room 18 disposed at the lower part of the casing 12. Further, as components constituting the refrigeration cycle, a compressor 19 housed in the upper machine chamber 16, an evaporator 20 housed on the back side of the freezer room 18, and a main condenser 21 housed in the lower machine chamber 15 are provided. Have. In addition, it has a partition wall 22 that partitions the lower machine chamber 15, a fan 23 that is attached to the partition wall 22 and cools the main condenser 21, an evaporating dish 24 installed on the leeward side of the partition wall 22, and a bottom plate 25 of the lower machine chamber 15. Yes.

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

  In addition, a plurality of air intakes 26 provided in 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 exhaust port 27 of the lower machine room 15 and the upper machine room 16 are provided. doing. Here, the lower machine chamber 15 is divided into two chambers by a partition wall 22, and a main condenser 21 is housed on the windward side of the fan 23 and an evaporating dish 24 is housed on the leeward side.

  Further, as components constituting the refrigeration cycle, the refrigerant is positioned on the downstream side of the main condenser 21, the dryer 38 for drying the circulating refrigerant, and the downstream of the dryer 38, the flow path switching valve 40 for controlling the refrigerant flow. , A dew-proof pipe 41 that is located downstream of the flow path switching valve 40 and is thermally coupled to the outer surface of the casing 12 around the opening of the freezer compartment 18, a throttle 44 that is a decompression mechanism of the refrigeration cycle, and the evaporator 20. have. The flow path switching valve 40 switches the flow path cross-sectional area steplessly using a needle valve mechanism to control the flow path resistance, so that the condensation temperature of the dew prevention pipe 41 is 0-10 compared to the main condenser 21. The temperature can be lowered. The flow path resistance of the flow path switching valve 40 that determines the condensation temperature difference between the dew proof pipe 41 and the main condenser 21 is “low resistance” with little difference in condensation temperature, and the difference in condensation temperature is 3 to 6 ° C. It is used with a default value in three stages: “High resistance” and “Closed” to fully close the flow path.

  Here, the flow path switching valve 40 is housed in the lower machine chamber 15 to suppress the resonance of the piping caused by the vibration of the compressor 19 in the upper machine chamber 16. In addition, the flow path switching valve 40 is disposed at the lower part of the casing 12, the compressor 19 is disposed at the upper part of the casing 12, and the flow path of the dew prevention pipe 41 is set to a substantially upward flow with almost no trap structure. Thus, the amount of refrigerant staying inside during use can be reduced. Further, the dew-proof pipe 41 is designed to have a heat radiation amount necessary for preventing condensation around the opening of the freezer compartment 18 when the periphery of the refrigerator 11 is in a high humidity environment.

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

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

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

  In the PC cooling mode, when the fan 23 is driven, the main condenser 21 side of the lower machine chamber 15 partitioned by the partition wall 22 has a negative pressure, and external air is sucked from the plurality of intake ports 26, and the evaporating dish 24 side has a positive pressure. Then, the air in the lower machine chamber 15 is discharged to the outside from the plurality of discharge ports 27.

  On the other hand, the refrigerant discharged from the compressor 19 is condensed while leaving a part of the gas while exchanging heat with the outside air in the main condenser 21. Then, the moisture is removed by the dryer 38, and the refrigerant is prevented via the flow path switching valve 40. Supplied to the dew pipe 41. The refrigerant passing through the dew-proof pipe 41 dissipates heat while condensing the opening of the freezer compartment 18, and is then decompressed by the throttle 44 and evaporated by the evaporator 20. At this time, heat is exchanged with the air in the refrigerator compartment 17 to cool the refrigerator compartment 17, and then it is returned to the compressor 19 as a gaseous refrigerant.

  Here, the operation of the flow path switching valve 40 will be described.

  In FIG. 3, g1, g2, and g3 indicate operating sections of the refrigeration cycle, and h1 and h2 indicate stop sections of the refrigeration cycle. In each of the sections g 1, g 2, and g 3, the compressor 19 is operated, and the flow path switching valve 40 is switched to “high resistance” so that the condensation temperature of the dew prevention pipe 41 is 3 as compared with the main condenser 21. Reduced by ~ 6 ° C before use. Further, in each of the sections h1 and h2, the flow path switching valve 40 is switched to “closed” to close the flow path, thereby preventing the refrigerant in the main condenser 21 from flowing into the evaporator 20 due to a pressure difference. . Further, during a predetermined time t immediately after the refrigeration cycle is stopped, the compressor 19 is operated with the flow path switching valve 40 in the “closed” state. As a result, the refrigerant staying in the dew prevention pipe 41 is recovered, and the high temperature refrigerant in the dew prevention pipe 41 is prevented from flowing into the evaporator 20 due to a pressure difference while the refrigeration cycle is stopped.

  In FIG. 3, the representative temperature of the opening of the freezer compartment 18 heated by the dew proof pipe 41 is shown as the surface temperature of the housing. As described above, when the flow path switching valve 40 is switched to “large resistance”, the condensation temperature of the dew proof pipe 41 can be stably operated in a state of being reduced by 3 to 6 ° C. compared to the main condenser 21. As a result, the temperature of the dew prevention pipe 41 is also raised and lowered according to the rise and fall of the outside air temperature, so that dew prevention is achieved while suppressing condensation on the outer surface of the casing 12 around the opening of the freezer compartment 18 at a predetermined relative humidity. The amount of heat entering due to the pipe 41 can be reduced.

  Further, when the ambient relative humidity exceeds a predetermined value for a long time, for example, the flow path switching valve 40 is set to “low resistance” based on the relative humidity around the refrigerator detected by a humidity sensor (not shown). By switching, the condensation temperature of the dew proof pipe 41 can be maintained substantially equal to that of the main condenser 21, so that condensation on the outer surface of the casing 12 around the opening of the freezer compartment 18 can be avoided.

  Further, when there is no door opening / closing or high temperature food input, and the loads in the refrigerator compartment 17 and the freezer compartment 18 are small, the compressor 19 is operated at a low speed in order to operate the refrigerating cycle with high efficiency. At this time, by combining the flow path resistances of the flow path switching valve 40 and the throttle 44, loss due to insufficient throttling of the refrigeration cycle that occurs when the compressor 19 is operated at a low speed can be suppressed, thus further improving the refrigeration cycle efficiency. can do.

  In the first embodiment, the flow path switching valve 40 switches the flow path resistance at two levels of “low resistance” and “high resistance”. However, the intrusion heat amount due to the dew prevention pipe 41 is reduced and the refrigeration cycle is switched. In consideration of suppression of loss due to insufficient throttling, the flow path resistance value may be adjusted steplessly to the optimum operating conditions.

  In this way, by controlling the temperature of the dew prevention pipe 41 using the flow path switching valve 40, it is not necessary to perform the recovery operation of the refrigerant staying in the dew prevention pipe 41 during the operation of the refrigeration cycle. The amount of intrusion heat caused by the dew prevention pipe 41 can be reduced while suppressing an increase in the amount of electric power accompanying the recovery operation and condensation on the outer surface of the housing 12. Moreover, the flow path in the dew prevention pipe 41 is made substantially upward, and the amount of refrigerant that remains is reduced, so that the flow path switching valve 40 is closed and the compressor 19 is operated to reduce the load for refrigerant recovery. Can do.

  During the PC cooling mode, when the temperature detected by the FCC temperature sensor 34 rises to a predetermined value FCC_OFF temperature and the temperature detected by the PCC temperature sensor 35 falls to a predetermined value PCC_OFF temperature, a transition is made to the OFF mode.

  In addition, when the temperature detected by the FCC temperature sensor 34 is higher than the predetermined FCC_OFF temperature and the temperature detected by the PCC temperature sensor 35 falls to the predetermined PCC_OFF temperature during the PC cooling mode, the freezer damper 31 is opened, the refrigerator compartment damper 32 is closed, and the compressor 19, the fan 23, and the evaporator fan 30 are driven. Thereafter, by operating the refrigeration cycle in the same manner as PC cooling, the freezer compartment 18 is heat-exchanged with the inside air of the freezer compartment 18 and the evaporator 20 to cool the freezer compartment 18 (this operation is hereinafter referred to as “FC cooling mode”). .

  During the FC cooling mode, when the temperature detected by the FCC temperature sensor 34 falls to a predetermined FCC_OFF temperature and the temperature detected by the PCC temperature sensor 35 is equal to or higher than the predetermined PCC_ON temperature, the PC cooling mode is entered. .

  Further, when the temperature detected by the FCC temperature sensor 34 falls to a predetermined FCC_OFF temperature and the temperature detected by the PCC temperature sensor 35 indicates a temperature lower than the predetermined PCC_ON temperature during the FC cooling mode, the OFF mode Transition to.

(Embodiment 2)
FIG. 4 is a cycle configuration diagram of the refrigerator according to the second embodiment of the present invention, and FIG. 5 is a diagram illustrating the operation of the flow path switching valve of the refrigerator according to the second embodiment. Hereinafter, a second embodiment of the present invention will be described with reference to the drawings. The same components as those of the first embodiment will be denoted by the same reference numerals, and detailed description thereof will be omitted.

  In FIG. 4, the components constituting the refrigeration cycle are located downstream of the main condenser 21, the dryer 38 for drying the circulating refrigerant, the downstream of the dryer 38, and the flow path switching for controlling the refrigerant flow A dew-proof pipe 41 that is located downstream of the valve 42 and the flow path switching valve 42 and is thermally coupled to the outer surface of the casing 12 around the opening of the freezer 18, a throttle 44 that is a refrigeration cycle decompression mechanism, and evaporation A container 20 is provided. The flow path switching valve 42 switches whether the refrigerant flowing from the dryer 38 is supplied directly to the dew prevention pipe 41 or supplied to the dew prevention pipe 41 via the intermediate resistor 43. The intermediate resistor 43 is formed of a thin tube having an inner diameter of 0.9 mm and a length of 1200 mm, and has a flow path resistance, so that the condensation temperature of the dew prevention pipe 41 can be lowered by 3 to 6 ° C. compared to the main condenser 21. The flow path switching valve 42 that determines the flow path to the dew proof pipe 41 fully closes the “flow path A” that flows directly, the “flow path B” that flows via the intermediate resistor 43, and the flow path. It is possible to switch to three stages of “closed”.

  Here, the flow path switching valve 42 is housed in the lower machine chamber 15 and suppresses the resonance of the piping caused by the vibration of the compressor 19 in the upper machine chamber 16. In addition, the flow path switching valve 42 is disposed at the lower part of the casing 12, the compressor 19 is disposed at the upper part of the casing 12, and the flow path of the dew proof pipe 41 is set to a substantially upward flow having almost no trap structure. Thus, the amount of refrigerant staying inside during use can be reduced. Further, the dew-proof pipe 41 is designed to have a heat radiation amount necessary for preventing condensation around the opening of the freezer compartment 18 when the periphery of the refrigerator 11 is in a high humidity environment.

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

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

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

  In the PC cooling mode, when the fan 23 is driven, the main condenser 21 side of the lower machine chamber 15 partitioned by the partition wall 22 has a negative pressure, and external air is sucked from the plurality of intake ports 26, and the evaporating dish 24 side has a positive pressure. Then, the air in the lower machine chamber 15 is discharged to the outside from the plurality of discharge ports 27.

  On the other hand, the refrigerant discharged from the compressor 19 is condensed while leaving a part of the gas while exchanging heat with the outside air in the main condenser 21. Then, the moisture is removed by the dryer 38 and is prevented through the flow path switching valve 42. Supplied to the dew pipe 41. The refrigerant passing through the dew-proof pipe 41 dissipates heat while condensing the opening of the freezer compartment 18, and is then decompressed by the throttle 44 and evaporated by the evaporator 20. At this time, heat is exchanged with the air in the refrigerator compartment 17 to cool the refrigerator compartment 17, and then it is returned to the compressor 19 as a gaseous refrigerant.

  Here, the operation of the flow path switching valve 42 will be described.

  In FIG. 5, g1, g2, and g3 indicate operating sections of the refrigeration cycle, and h1 and h2 indicate stop sections of the refrigeration cycle. In each of the sections g 1, g 2, and g 3, the compressor 19 is operated, and the flow path switching valve 42 is switched to “flow path B” so that the condensation temperature of the dew prevention pipe 41 is compared with that of the main condenser 21. Reduce the temperature by 3-6 ° C and use. In each of the sections h1 and h2, the flow path switching valve 42 is switched to “closed” to close the flow path, thereby preventing the refrigerant in the main condenser 21 from flowing into the evaporator 20 due to a pressure difference. . Further, during a predetermined time t immediately after the refrigeration cycle is stopped, the compressor 19 is operated with the flow path switching valve 42 in the “closed” state. As a result, the refrigerant staying in the dew prevention pipe 41 is recovered, and the high temperature refrigerant in the dew prevention pipe 41 is prevented from flowing into the evaporator 20 due to a pressure difference while the refrigeration cycle is stopped.

  In FIG. 5, the representative temperature of the opening of the freezer compartment 18 heated by the dew proof pipe 41 is shown as the surface temperature of the housing. As described above, when the flow path switching valve 42 is switched to “flow path B”, the condensation temperature of the dew proof pipe 41 can be stably operated in a state in which the condensation temperature is lowered by 3 to 6 ° C. compared to the main condenser 21. . As a result, the temperature of the dew prevention pipe 41 is also raised and lowered according to the rise and fall of the outside air temperature, so that dew prevention is achieved while suppressing condensation on the outer surface of the casing 12 around the opening of the freezer compartment 18 at a predetermined relative humidity. The amount of heat entering due to the pipe 41 can be reduced.

  Further, when the ambient relative humidity exceeds a predetermined value for a long time, for example, based on the relative humidity around the refrigerator detected by a humidity sensor (not shown), the channel switching valve 42 is set to “channel A”. By switching to, the condensation temperature of the dew proof pipe 41 can be maintained substantially the same as that of the main condenser 21, so that condensation on the outer surface of the casing 12 around the opening of the freezer compartment 18 can be avoided. .

  Further, when there is no door opening / closing or high temperature food input, and the loads in the refrigerator compartment 17 and the freezer compartment 18 are small, the compressor 19 is operated at a low speed in order to operate the refrigerating cycle with high efficiency. At this time, by combining the flow resistance of the intermediate resistor 43 and the throttle 44, loss due to insufficient throttling of the refrigeration cycle that occurs when the compressor 19 is operated at a low speed can be suppressed, so that the refrigeration cycle efficiency is further improved. be able to.

  In the second embodiment, the intermediate resistor 43 made of a thin tube having an inner diameter of 0.9 mm and a length of 1200 mm is used. However, the inner diameter and the length may be adjusted in order to obtain the same flow path resistance. . However, since the dryness of the outlet of the intermediate resistor 43 is larger than that of the inlet of the throttle 44, the flow path cross-sectional area larger than that of the throttle 44, preferably a flow path cross-sectional area similar to that of a small diameter pipe having an inner diameter of 0.8 mm or more. It is desirable to ensure.

  In this way, by controlling the temperature of the dew prevention pipe 41 using the flow path switching valve 42, it is not necessary to perform a recovery operation of the refrigerant staying in the dew prevention pipe 41 during the operation of the refrigeration cycle. The amount of intrusion heat caused by the dew prevention pipe 41 can be reduced while suppressing an increase in the amount of electric power accompanying the recovery operation and condensation on the outer surface of the housing 12. Further, by reducing the amount of refrigerant that stays in the flow path in the dew-proof pipe 41 and reducing the amount of refrigerant that remains, the load that collects the refrigerant by operating the compressor 19 by closing the flow path switching valve 42 is reduced. Can do.

(Embodiment 3)
6 is a cycle configuration diagram of the refrigerator in the third embodiment of the present invention, and FIG. 7 is a diagram showing the operation of the flow path switching valve of the refrigerator in the third embodiment. Hereinafter, Embodiment 3 of the present invention will be described with reference to the drawings. The same components as those in Embodiment 1 or Embodiment 2 are given the same reference numerals, and detailed description thereof will be omitted.

  In FIG. 6, the components constituting the refrigeration cycle are located on the downstream side of the main condenser 21 and are located on the downstream side of the dryer 38 for drying the circulating refrigerant and the flow path switching for controlling the flow of the refrigerant. A dew pipe 41 that is located downstream of the valve 45, the flow path switching valve 45, and is thermally coupled to the outer surface of the housing 12 around the opening of the freezing chamber 18, a throttle 44 that is a decompression mechanism of the refrigeration cycle, and evaporation A container 20 is provided. The flow path switching valve 45 supplies the refrigerant flowing from the dryer 38 directly to the dew prevention pipe 41, or supplies the refrigerant to the dew prevention pipe 41 through the intermediate resistor 43, or a bypass composed of a bypass 46 and a restriction 47. It is to switch whether to supply to the circuit. The intermediate resistor 43 is formed of a thin tube having an inner diameter of 0.9 mm and a length of 1200 mm, and has a flow path resistance, so that the condensation temperature of the dew prevention pipe 41 can be lowered by 3 to 6 ° C. compared to the main condenser 21.

  The bypass 46 is a pipe that connects the flow path switching valve 45 and the throttle 47 in the shortest distance, and has a smaller internal volume than the dew proof pipe 41 and is insulated from the outside. The restrictor 47 is a pipe having a flow path resistance equivalent to that of the restrictor 44 and connecting the bypass 46 and the evaporator 20.

  In addition, the flow path switching valve 45 includes a “flow path A” that flows directly to the dew prevention pipe 41, a “flow path B” that flows to the dew prevention pipe 41 via the intermediate resistor 43, and the bypass 46 to the throttle 47. It is possible to switch to four stages of “flow path C” that circulates and “closed” that fully closes the flow path.

  Here, the flow path switching valve 45 is housed in the lower machine chamber 15 to suppress the resonance of the piping caused by the vibration of the compressor 19 in the upper machine chamber 16. In addition, the flow path switching valve 45 is disposed at the lower part of the casing 12, the compressor 19 is disposed at the upper part of the casing 12, and the flow path of the dew proof pipe 41 is set to a substantially upward flow with almost no trap structure. Thus, the amount of refrigerant staying inside during use can be reduced. Further, the dew-proof pipe 41 is designed to have a heat radiation amount necessary for preventing condensation around the opening of the freezer compartment 18 when the periphery of the refrigerator 11 is in a high humidity environment.

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

  The operation of the refrigerator according to the third embodiment configured as described above will be described below, but the same reference numerals are given to the same components as those of the first or second embodiment, and the detailed description thereof is omitted. To do.

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

  In the PC cooling mode, when the fan 23 is driven, the main condenser 21 side of the lower machine chamber 15 partitioned by the partition wall 22 has a negative pressure, and external air is sucked from the plurality of intake ports 26, and the evaporating dish 24 side has a positive pressure. Then, the air in the lower machine chamber 15 is discharged to the outside from the plurality of discharge ports 27.

  On the other hand, the refrigerant discharged from the compressor 19 is condensed while leaving a part of the gas while exchanging heat with the outside air in the main condenser 21, and then moisture is removed by the dryer 38 and is prevented via the flow path switching valve 45. Supplied to the dew pipe 41. The refrigerant passing through the dew-proof pipe 41 dissipates heat while condensing the opening of the freezer compartment 18, and is then decompressed by the throttle 44 and evaporated by the evaporator 20. At this time, heat is exchanged with the air in the refrigerator compartment 17 to cool the refrigerator compartment 17, and then it is returned to the compressor 19 as a gaseous refrigerant.

  Here, the operation of the flow path switching valve 45 will be described.

  In FIG. 7, g1, g2, and g3 indicate operating sections of the refrigeration cycle, and h1 and h2 indicate stop sections of the refrigeration cycle. In each of the sections g1, g2, and g3, the compressor 19 is operated, and the flow path switching valve 45 is switched to “flow path C” for a predetermined time s immediately after the start of the refrigeration cycle. Drive 19. Accordingly, the use of the bypass 46 having a smaller internal volume than the dew proof pipe 41 can improve the rising characteristics of the refrigeration cycle. Thereafter, the flow path switching valve 45 is switched to “flow path B”, and the condensation temperature of the dew proof pipe 41 is lowered by 3 to 6 ° C. compared to the main condenser 21.

  Further, in each of the sections h1 and h2, the flow path switching valve 45 is switched to “closed” to close the flow path, thereby preventing the refrigerant in the main condenser 21 from flowing into the evaporator 20 due to a pressure difference. . Further, during a predetermined time t immediately after the refrigeration cycle is stopped, the compressor 19 is operated with the flow path switching valve 45 in the “closed” state. As a result, the refrigerant staying in the dew prevention pipe 41 is recovered, and the high temperature refrigerant in the dew prevention pipe 41 is prevented from flowing into the evaporator 20 due to a pressure difference while the refrigeration cycle is stopped.

  Moreover, in FIG. 7, the representative temperature of the opening part of the freezer compartment 18 heated by the dew prevention pipe 41 is shown as the surface temperature of the housing. As described above, when the flow path switching valve 45 is switched to “flow path B”, the condensation temperature of the dew proof pipe 41 can be stably operated in a state in which the condensation temperature is lowered by 3 to 6 ° C. compared to the main condenser 21. . As a result, the temperature of the dew prevention pipe 41 is also raised and lowered according to the rise and fall of the outside air temperature, so that dew prevention is achieved while suppressing condensation on the outer surface of the casing 12 around the opening of the freezer compartment 18 at a predetermined relative humidity. The amount of heat entering due to the pipe 41 can be reduced.

  Further, when the ambient relative humidity exceeds a predetermined value for a long time, for example, the channel switching valve 45 is set to “channel A” based on the relative humidity around the refrigerator detected by a humidity sensor (not shown). By switching to, the condensation temperature of the dew proof pipe 41 can be maintained substantially the same as that of the main condenser 21, so that condensation on the outer surface of the casing 12 around the opening of the freezer compartment 18 can be avoided. .

  In the third embodiment, the flow path resistance of the throttle 47 is equal to that of the throttle 44, but the flow path resistance of the throttle 47 is made smaller than that of the throttle 44 in order to further improve the startability of the refrigeration cycle. May be.

In this way, by controlling the temperature of the dew prevention pipe 41 using the flow path switching valve 45, it is not necessary to perform a recovery operation of the refrigerant staying in the dew prevention pipe 41 during the operation of the refrigeration cycle. The amount of intrusion heat caused by the dew prevention pipe 41 can be reduced while suppressing an increase in the amount of electric power accompanying the recovery operation and condensation on the outer surface of the housing 12. Further, by reducing the amount of refrigerant that stays in the flow path in the dew prevention pipe 41 and reducing the amount of refrigerant that remains, the load that collects the refrigerant by operating the compressor 19 by closing the flow path switching valve 45 is reduced. Can do.

  As described above, the refrigerator of the present invention has a resistance switching mechanism that varies the flow path resistance of the refrigerant between the main condenser 21 and the dew prevention pipe 41, and the condensation temperature of the dew prevention pipe 41 as necessary. Is lower than that of the main condenser 21, so that it is not necessary to perform the recovery operation of the refrigerant staying in the dew prevention pipe 41 during the operation of the refrigeration cycle. While suppressing dew condensation on the outer surface, the amount of intrusion heat caused by the dew prevention pipe 41 can be reduced, and energy saving of the refrigerator can be achieved.

  In addition, the refrigerator of the present invention can suppress the amount of refrigerant staying inside the dew prevention pipe 41 during use by making the flow in the dew prevention pipe 41 having the largest amount of intrusion heat a substantially upward flow. Further energy saving can be achieved by suppressing the refrigerant recovery operation during stoppage.

  As described above, the refrigerator according to the present invention uses the resistance switching mechanism to lower the condensation temperature of the dew proof pipe from the main condenser, thereby preventing the dew proof pipe sweating performance depending on the installation environment and operating state of the refrigerator. Energy conservation can be achieved while maintaining it, so it can also be applied to other refrigerated products such as commercial refrigerators.

DESCRIPTION OF SYMBOLS 11 Refrigerator 12 Case 15 Lower machine room 16 Upper machine room 19 Compressor 20 Evaporator 21 Main condenser 30 Evaporator fan 31 Freezer damper 32 Refrigerator damper 33 Duct 34 FCC temperature sensor 35 PCC temperature sensor 40, 42, 45 Flow path switching valve 43 Intermediate resistor 41 Dew proof pipe 44 Restriction 46 Bypass 47 Restriction

Claims (8)

A refrigeration cycle having at least a compressor, an evaporator, a main condenser, a dew proof pipe, and a throttle, the main condenser, a dew proof pipe downstream of the main condenser, the main condenser and the proof A refrigerator having a resistance switching mechanism that is connected to a dew pipe and varies a flow path resistance of the refrigerant. It has a resistance switching mechanism consisting of a flow path switching valve that switches the cross-sectional area of the flow path steplessly using a needle valve, and the resistance switching mechanism is connected between the main condenser and the dew-proof pipe. The refrigerator according to claim 1. A resistance switching mechanism comprising an intermediate resistor composed of a small-diameter tube, a bypass pipe that bypasses the intermediate resistor, and a flow path switching valve that switches between the intermediate resistor and the bypass pipe. The refrigerator according to claim 1, wherein the resistance switching mechanism is connected to a dew pipe. The refrigerator according to claim 3, further comprising an intermediate resistor made of a thin tube having an inner diameter of 0.8 mm or more. 5. The temperature of the dew proof pipe is made lower than that of the main condenser by increasing the resistance of the resistance switching mechanism when the refrigeration cycle is operated under normal conditions. Refrigerator. A resistance switching mechanism, a dew proof pipe and a throttle connected in parallel to each other, a bypass pipe bypassing the resistance switching mechanism and the dew proof pipe, the bypass pipe and the evaporator connected, and a second throttle having a flow path resistance And a flow path switching valve for switching the flow path of the resistance switching mechanism and the bypass piping, and the bypass piping is used at the start of the refrigeration cycle. The refrigerator described. An upper machine room and a lower machine room are provided, a compressor is arranged in the upper machine room, and a resistance switching mechanism is arranged in the lower machine room. The refrigerator described. 8. The refrigerator according to claim 7, wherein an outlet of the dew proof pipe is disposed in the upper machine room, and a flow direction of the dew proof pipe is set substantially upward.

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