JP6197176B2 - refrigerator - Google Patents

Description

  The present invention relates to a refrigerator having a switching valve for switching a dew proof pipe and reducing a heat load caused by the dew proof pipe by operating a refrigeration cycle while not using some of the dew proof pipe. is there.

  From the viewpoint of energy saving, household refrigerators have a switching valve that switches dew-proof pipes, and by operating the refrigeration cycle while not using some of the dew-proof pipes, the heat load caused by the dew-proof pipes There is a refrigerator to reduce the. This is because, in light load conditions where the temperature and humidity around the refrigerator are relatively low, some of the dew-proof pipes are temporarily disabled, and the temperature of the dew-proof pipes and their surroundings is set to such an extent that the housing surface does not sweat. By lowering, 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. 4 is a longitudinal sectional view of a conventional refrigerator, FIG. 5 is a configuration diagram of a refrigeration cycle of the conventional refrigerator, and FIG. 6 is a diagram showing the operation of the flow path switching valve of the conventional refrigerator.

  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 in a lower portion of the housing 12, and a refrigeration disposed in an upper portion 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. Then, in order to temporarily disable the dew proof pipe 60, the flow path switching valve 40 that branches upstream of the dew proof pipe 60, and the dew proof pipe 60 between the flow path switching valve 40 and the evaporator 20 are connected. A bypass circuit 61, a dryer 39, and a diaphragm 45 are connected in parallel.

Further, the evaporator fan 5 that supplies the cold air generated in the evaporator 20 to the refrigerator compartment 17 and the freezer compartment 18.
0, a freezer damper 51 that blocks cold air supplied to the freezer room 18, a refrigerator room damper 52 that blocks cold air supplied to the refrigerator room 17, a duct 53 that supplies cold air to the refrigerator room 17, and the temperature of the freezer room 18 FCC temperature sensor 54 for detecting the temperature, PCC temperature sensor 55 for detecting the temperature of the refrigerator compartment 17, and DEF temperature sensor 58 for detecting the temperature of the evaporator 20.

  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 40 will be described.

  In FIG. 6, 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 40 is switched to intermittently use the dew-proof pipe 60. Moreover, in FIG. 6, the representative temperature of the opening part of the freezer compartment 18 heated by the dew prevention pipe 60 is shown as the surface temperature of the housing. The operation “opening and closing” of the flow path switching valve 40 opens the flow path on the dew prevention pipe 60 side and closes the flow path on the bypass 61 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 61 side, so that the refrigerant in the main condenser 21 flows into the bypass 61 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 61 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 61 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 dew proof pipe 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 61 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 61 are alternately switched, the refrigerant that stays inside the dew-proof pipe 60 is recovered, particularly after the dew-proof pipe 60 is used and switched to the bypass 61. 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 61 and to suppress the amount of refrigerant staying inside the dew-proof pipe 60 during use.

  An object of the present invention is to solve the conventional problems, and while maintaining the antiperspiration performance while suppressing the number of switching during operation, it is an object of the present invention to suppress the amount of accumulated refrigerant by improving the dewproof pipe configuration. To do.

In order to solve the conventional problems, a refrigerator according to the present invention includes a refrigeration cycle having at least a compressor, an evaporator, a main condenser, a dew condensation pipe, and a throttle, and a flow path connected to the downstream side of the main condenser. A switching valve, a plurality of dew-proof pipes connected in parallel to the downstream side of the flow path switching valve, and a throttle connected to the downstream side of each of the dew-proof pipes, and the refrigeration cycle has an ambient temperature and humidity When operating under light load conditions lower than a predetermined value, the refrigerant flows alternately through the plurality of dew-proof pipes.When starting the compressor, the most intrusion heat amount is based on the most recent operation time and stop time of the compressor. The use time and non-use time of a large dew-proof pipe are determined, and whether to use the dew-proof pipe with the largest amount of intrusion heat at the start of the compressor is switched .

  This reduces the number of times the dew-proof pipe is switched, and adjusts the ratio between the time when the dew-proof pipe is used and the time when it is not used based on the humidity around the refrigerator. When the humidity is low, the surface temperature of the housing is lowered to reduce sweating and save energy.

  Moreover, in order to solve the conventional problem, the refrigerator of the present invention is characterized in that the flow in the dew-proof pipe is substantially ascending.

  As a result, it is possible to suppress the amount of refrigerant that stays inside the dew-proof pipe during use.

  The refrigerator of the present invention can reduce the number of times of switching of the dew-proof pipe and suppress the amount of refrigerant that stays inside the dew-proof pipe during use, thereby achieving further energy saving while maintaining anti-perspiration performance. it can.

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 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

A first aspect of the present invention includes a refrigeration cycle having at least a compressor, an evaporator, a main condenser, a dew proof pipe, and a throttle, and a flow path switching valve connected to the downstream side of the main condenser, and the flow path switching valve A plurality of dew-proof pipes connected in parallel to the downstream side of the dewatering pipe and a throttle connected to the downstream side of each of the dew-proof pipes, and the refrigeration cycle is operated under light load conditions where the ambient temperature and humidity are lower than predetermined. If you intended to flow refrigerant alternately to the plurality of anti-condensation pipe, when starting the compressor, the use of large anti-condensation pipe of the most entering heat based on the most recent operating time and stop time of the compressor time and not It determines the usage time and switches whether or not to use the dew-proof pipe with the largest amount of intrusion heat when starting up the compressor .

  In this way, by adjusting the ratio between the time when the specified dew-proof pipe is used and the time when it is not used, while maintaining anti-perspiration performance, the amount of heat entering the dew-proof pipe is suppressed to save energy. Can do.

In addition , every time the compressor is started, whether or not to use the dew-proof pipe with the largest amount of intrusion heat is switched at the time of starting the compressor.

  As a result, even if the number of times of switching is reduced, the perspiration prevention performance can be maintained by adjusting the ratio between the time when the predetermined dew-proof pipe is used and the time when it is not used. It is possible to save energy by suppressing a reduction in cycle efficiency.

  Usually, in order to maintain perspiration prevention performance, it is necessary to adjust the time ratio of using a dew-proof pipe with a large amount of intrusion heat according to the temperature and humidity environment around the refrigerator. In conventional refrigerators, the order of switching the dew-proof pipes is fixed, and the time to use and not to use the dew-proof pipes with a large amount of intrusion heat is set to be significantly shorter than the compressor operation time. By switching frequently, the time ratio for using a dew-proof pipe with a large amount of intrusion heat is adjusted.

However, if the dew-proof pipe with a large amount of intrusion heat is switched frequently during operation of the compressor, the efficiency of the refrigeration cycle is reduced when the refrigerant staying in the dew-proof pipe is recovered, and the intrusion heat amount is suppressed. This will offset the energy saving effect. Therefore, in the second invention, every time the compressor is started, by switching whether or not to use the dew-proof pipe with the largest amount of intrusion heat at the time of starting the compressor, The unused time can be set to the same level as the operation time of the compressor, and the number of switching times can be reduced.

Further , when the compressor is started, the usage time and non-use time of the dew-proof pipe having the largest amount of intrusion heat are determined based on the latest operation time and stop time of the compressor.

  As a result, the total usage time and non-use time of the dew-proof pipe can be adjusted to the same level as the most recent operation time and stop time of the compressor according to fluctuations in the operating state of the refrigerator, and the anti-perspiration performance can be improved. A minimum number of switching times can be realized while maintaining.

According to a second invention, in the first invention, an upper machine room and a lower machine room are provided, the compressor is arranged in the upper machine room, and the flow path switching valve is arranged in the lower machine room. It is.

  Thereby, the noise of the refrigerator can be reduced by suppressing the resonance between the connecting pipe of the flow path switching valve and the compressor.

According to a third invention, in the second invention, the confluence of a plurality of dew prevention pipes is arranged in the upper machine room, and the flow direction of the dew prevention pipes is substantially upward.

  This makes it possible to reduce the amount of refrigerant that stays in the dew prevention pipe by making the flow direction of the plurality of dew prevention pipes one direction, and the refrigeration cycle that occurs when collecting the refrigerant that stays in the dew prevention pipe The efficiency drop can be suppressed.

  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. The dew pipe A41, which is located downstream of the flow path switching valve 40 and is thermally coupled to the outer surface of the housing 12 around the opening of the freezer compartment 18, and the flow path switching valve 40 in parallel with the dew prevention pipe A41. It has a dew-proof pipe B42 that is located on the downstream side and radiates heat in contact with the back surface of the housing 12. The flow path switching valve 40 can control the opening and closing of the flow of a single refrigerant for each of the dew prevention pipe A41 and the dew prevention pipe B42. The dew-proof pipe B42 has substantially the same internal volume and heat dissipation capability as the dew-proof pipe A41, radiates heat in contact with the back surface of the housing 12, and is disposed overlapping the vacuum heat insulating material 43 to enter the interior of the housing 12. Heat transfer, that is, the amount of intrusion heat is suppressed. Further, the dew-proof pipe A41 and the dew-proof pipe B42 are connected to the evaporator 20 via a throttle A44 and a throttle B45, respectively.

  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. Further, the flow path switching valve 40 is arranged at the lower part of the casing 12, the compressor 19 is arranged at the upper part of the casing 12, and the flow paths in the dew-proof pipe A41 and the dew-proof pipe B42 have almost no trap structure. By setting it as a substantially upward flow, the amount of refrigerant staying inside during use can be reduced. Further, the dew-proof pipe A41 has a larger amount of intrusion heat than the dew-proof pipe B42 and increases the heat load of the housing 12, but the freezer compartment 18 is adapted to the case where the periphery of the refrigerator 11 is in a high humidity environment. It is designed with a heat dissipation amount necessary to prevent condensation around the opening of the.

  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. It is supplied to the dew pipe A41 or the dew prevention pipe B42. The refrigerant that has passed through the dew-proof pipe A41 radiates and condenses to the outside through the housing 12 while warming the opening of the freezer compartment 18 and is then decompressed by the throttle 44 and evaporated by the evaporator 20 while being stored in the refrigerator compartment 17. While refrigerating the refrigeration chamber 17 by exchanging heat with the internal air, the refrigerant is returned to the compressor 19 as a gaseous refrigerant. On the other hand, the refrigerant that has passed through the dew-proof pipe B42 radiates and condenses to the outside through the rear surface of the housing 12, and is then decompressed by the throttle 45 and evaporated in the evaporator 20 while being heated in the refrigerator compartment air and heat. While being exchanged and cooling the refrigerator compartment 17, the refrigerant 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 g1, g2, and g3, the compressor 19 is operated, and the flow switching valve 40 is switched to alternately use the dew-proof pipe A41 or the dew-proof pipe B42. The operation “opening / closing” of the flow path switching valve 40 opens the flow path on the dew-proof pipe A41 side and closes the flow path on the dew-proof pipe B42 side so that the refrigerant in the main condenser 21 enters the dew-proof pipe A41. While flowing, the refrigerant staying in the dew proof pipe B42 is recovered to the evaporator 20. Similarly, “closed open” closes the flow path on the dew prevention pipe A41 side and opens the flow path on the dew prevention pipe B42 side, so that the refrigerant of the main condenser 21 flows into the dew prevention pipe B42, The refrigerant staying in the dew-proof pipe A41 is recovered to the evaporator 20. “Closed” means that the refrigerant on the main condenser 21 in the sections q1 and q2 where the compressor 19 is stopped by closing the flow path on the dew prevention pipe A41 side and closing the flow path on the dew prevention pipe B42 side. Is prevented from flowing into the evaporator 20 due to a pressure difference.

  Moreover, in FIG. 3, the representative temperature of the opening part of the freezer compartment 18 heated by dew-proof pipe A41 is shown as the surface temperature of the housing. The dew-proof pipe used at the beginning of the operating section of the refrigeration cycle is switched for each operating section, and the time K for using the dew-proof pipe A41 and the time L for using the dew-proof pipe B42 are controlled to control the dew-proof pipe A41. Is adjusted so that the average value of the surface temperature of the casing heated by the above becomes a predetermined level. For example, when the humidity is high by adjusting the ratio between the time K and the time L based on the humidity around the refrigerator detected by a humidity sensor (not shown), the time K when the dew-proof pipe A41 is used. Is increased to increase the surface temperature of the housing, and when the humidity is low, the time L for using the dew-proof pipe B42 is increased to lower the surface temperature of the housing, thereby making it possible to achieve both sweat prevention and energy saving.

  Thus, by switching the dew-proof pipe used at the beginning of the operating section of the refrigeration cycle for each operating section, the time K and the time L can be set to the same level as the operating section of the refrigeration cycle. It is possible to reduce the number of times of switching during the operation section to about once. In order to reduce the number of times of switching in the operating section of the refrigeration cycle, it is desirable to adjust so that the sum of time K and time L is approximately the same as or larger than the operating section of the refrigeration cycle. In addition, while starting the compressor, by determining the time K and time L based on the operation section and the stop section of the most recent refrigeration cycle, while maintaining the anti-perspiration performance according to the fluctuation of the operation rate of the refrigeration cycle A minimum number of switching times can be realized.

Furthermore, by using alternately the dew-proof pipes B42 that have the same heat dissipation capability as the dew-proof pipes A41 and that are arranged overlapping with the vacuum heat insulating material 43 to suppress the intrusion heat amount, the dew-proof pipes A41 are used. While suppressing the amount of intrusion heat, the heat dissipating capacity can be maintained when the dew-proof pipe A41 is not used, and a decrease in refrigeration cycle efficiency due to a decrease in heat dissipating capacity can be avoided. Further, the flow paths in the dew-proof pipe A41 and the dew-proof pipe B42 are made substantially upward flow, and by reducing the amount of accumulated refrigerant, the flow-path switching valve 40 is switched to alternately switch the dew-proof pipe A41 or the dew-proof pipe B42. It is possible to reduce the load required for collecting the refrigerant in the unused pipe that occurs when the pipe is used.

  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.

  As described above, the refrigerator of the present invention connects the dew-proof pipe A41 and the dew-proof pipe B42 in parallel via the flow path switching valve 40 to the downstream side of the main condenser 21, and every time the compressor 19 is started. By switching whether or not to use the dew-proof pipe A41 with the largest amount of intrusion heat when starting the compressor 19, the number of switching of the dew-proof pipe A41 is reduced and the dew-proof based on the temperature and humidity environment around the refrigerator By adjusting the ratio between the time K when the pipe A41 is used and the time L when it is not used, for example, the surface temperature of the housing 12 is increased when the humidity is high, and the surface temperature of the housing 12 is increased when the humidity is low. By lowering, both sweat prevention and energy saving can be achieved.

  In addition, the refrigerator of the present invention can suppress the amount of refrigerant staying inside the dew prevention pipe A41 during use by making the flow in the dew prevention pipe A41 having the largest amount of intrusion heat a substantially upward flow. Further energy savings can be achieved while maintaining antiperspirant performance.

  As described above, in the refrigerator according to the present invention, a plurality of dew prevention pipes are connected in parallel via the flow path switching valve on the downstream side of the main condenser, so that the dew prevention pipe sweats depending on the installation environment and operation state of the refrigerator. Since energy conservation can be achieved while maintaining the prevention performance, it can also be applied to other refrigerated products such as commercial refrigerators.

DESCRIPTION OF SYMBOLS 11 Refrigerator 12 Case 13 Door 14 Leg 15 Lower machine room 16 Upper machine room 17 Refrigeration room 18 Freezing room 19 Compressor 20 Evaporator 21 Main condenser 22 Bulkhead 23 Fan 24 Evaporating dish 25 Bottom plate 30 Evaporator fan 31 Freezer compartment damper 32 Cold room damper 33 Duct 34 FCC temperature sensor 35 PCC temperature sensor 36 DEF temperature sensor 38 Dryer 40 Flow path switching valve 41 Dew prevention pipe A
42 Dew prevention pipe B
43 Vacuum insulation 44 Aperture A
45 Aperture B

Claims (3)

A refrigeration cycle having at least a compressor, an evaporator, a main condenser, a dew proof pipe, and a throttle, and a flow path switching valve connected to the downstream side of the main condenser and a downstream side of the flow path switching valve in parallel A plurality of dew-proof pipes connected to each other and a throttle connected to the downstream side of each of the dew-proof pipes, and when the refrigeration cycle is operated under light load conditions where ambient temperature and humidity are lower than predetermined, The refrigerant flows alternately to the dew-proof pipe.When the compressor is started, the use time and non-use time of the dew-proof pipe with the largest amount of intrusion heat are determined based on the most recent operation time and stop time of the compressor. A refrigerator characterized by switching whether or not to use a dew-proof pipe with the largest amount of intrusion heat when starting up the compressor . An upper machine room and the lower machine room, the refrigerator according to claim 1, wherein while disposing the compressor in the upper machine room, characterized by arranging the flow path switching valve in the lower machine room. The refrigerator according to claim 2 , wherein a confluence of a plurality of dew prevention pipes is arranged in the upper machine room, and a flow direction of the dew prevention pipes is set substantially upward.

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