JP2013019598A - Refrigerator - Google Patents

Abstract

An object of the present invention is to provide a refrigerator-freezer having high power saving performance by performing defrosting of an evaporator with high efficiency.
In a refrigerator in which a compressor, a first condenser, a heat radiating pipe, a dryer, a first throttling device, and a first evaporator are sequentially connected, a second condenser provided in the vicinity of the first evaporator from the compressor. And a pipe connecting to the downstream of the heat radiating pipe through the second condenser, and a first switching valve for switching the refrigerant flow to the second condenser side, the high-temperature refrigerant discharged from the compressor during defrosting is It flows to a 2 condenser, and the frost adhering to a 1st evaporator is melt | dissolved by the heat conduction of a refrigerant | coolant.
[Selection] Figure 3

Description

  The present invention relates to a refrigerator.

  Generally, in a refrigerator, during cooling, moisture from outside air entering the cabinet by opening and closing the door and moisture from stored foods adheres to the surface of the evaporator at a low temperature to form frost. When the amount of frost adhesion increases, the heat exchange performance of the evaporator deteriorates, and the performance of the refrigerator-freezer decreases. For this reason, it is necessary to remove and reduce frost adhering to the evaporator, such as performing a defrosting operation at predetermined time intervals.

  In order to remove the frost adhering to this evaporator, in patent document 1, it has the structure provided with the heating means for a defrost in an evaporator. Direct heating means and indirect heating means have been proposed as the heating means. Defrosting with hot gas has been proposed as a direct heating means, and defrosting with an IH heater or electric heater as indirect means.

  Patent Document 2 discloses a configuration in which a bypass circuit is provided in the refrigeration cycle. When a large amount of frost adheres to the surface of the heat exchanger, the refrigerant is passed through the bypass circuit for defrosting.

JP 2000-121233 A JP 2005-249254 A

  The refrigerator-freezer disclosed in Patent Document 1 includes a four-way valve in the refrigeration cycle, switches the four-way valve at the time of defrosting, and causes the refrigerant to flow in the direction opposite to that during normal operation. The low-temperature and low-pressure refrigerant is sent to the condenser.

  However, in the above refrigeration cycle configuration, the specifications of the capillary tube are fixed, and the operating efficiency during defrosting is worse than that during normal operation.

  The refrigerator-freezer disclosed in Patent Document 2 has a three-way valve disposed in the refrigeration cycle, and at the time of defrosting, the three-way valve is switched to bypass the high-temperature and high-pressure refrigerant from the compressor to the evaporator and defrost. It has become.

  However, in the above refrigeration cycle configuration, a heat pump cannot be used during defrosting. Therefore, the coefficient of performance (= heating capacity / compressor power) is low and there is a problem in energy saving.

  The present invention has been made to solve the above-described problems of the prior art, and an object of the present invention is to provide a refrigerator-freezer having high power saving performance by performing defrosting of an evaporator with high efficiency.

  In order to solve the above problems, for example, the configuration described in the claims is adopted. The present application includes a plurality of means for solving the above-mentioned problems. For example, a refrigerator in which a compressor, a first condenser, a heat radiating pipe, a dryer, a first throttle device, and a first evaporator are connected in order. A second condenser provided in the vicinity of the first evaporator from the compressor, a pipe that passes through the second condenser and is connected to the downstream side of the heat radiating pipe, and a refrigerant flow that switches the refrigerant flow to the second condenser side. A high-temperature refrigerant discharged from the compressor during defrosting to the second condenser, and frost adhering to the first evaporator is melted by heat conduction of the refrigerant.

  ADVANTAGE OF THE INVENTION According to this invention, the defrost of an evaporator can be performed with high efficiency and the refrigerator refrigerator with high power saving performance can be provided.

The front external view of the refrigerator which concerns on embodiment of this invention. Sectional drawing of the refrigerator which concerns on embodiment of this invention. The figure showing an example of the refrigerating cycle structure of the refrigerator which concerns on 1st embodiment of this invention. The figure showing an example of the refrigerating cycle structure of the refrigerator which concerns on 2nd embodiment of this invention. The figure showing an example of the refrigerating cycle structure of the refrigerator which concerns on 3rd embodiment of this invention. The figure showing an example of the evaporator periphery of the refrigerator which concerns on embodiment of this invention. The flowchart figure of the refrigerant | coolant collection | recovery control before the defrost operation in 1st, 2nd embodiment of this invention. The flowchart figure of the refrigerant | coolant collection | recovery control at the time of completion | finish of the defrost operation in 1st, 2nd embodiment of this invention. The flowchart figure of the refrigerant | coolant collection | recovery control before the defrost operation in 3rd embodiment of this invention. The flowchart figure of the refrigerant | coolant collection | recovery control at the time of completion | finish of the defrost operation in 3rd embodiment of this invention.

  The first aspect of the present invention is a refrigerator in which a compressor, a first condenser, a heat radiating pipe, a dryer, a first throttling device, and a first evaporator are connected in order, and is provided in the vicinity of the first evaporator from the compressor. A second condenser, a pipe that passes through the second condenser and is connected to the downstream side of the heat radiating pipe, and a first switching valve that switches a refrigerant flow to the second condenser side. The discharged high-temperature refrigerant is caused to flow to the second condenser, and frost adhering to the first evaporator is melted by heat conduction of the refrigerant.

  A second evaporator provided between the downstream of the first throttle device and the downstream of the first evaporator; and a second switch for switching the refrigerant flow from the first evaporator side or the second evaporator side. The refrigerant that has radiated heat from the second condenser during the defrosting is depressurized by the throttling device, and then flows to the second evaporator.

  Further, the degree of aperture by the aperture device is variable.

  Further, the first switching valve is switched so that the refrigerant flows from the compressor to the first condenser, and the second switching valve is switched to flow from the first throttling device to the first evaporator. At the time of defrosting rather than during operation, the degree of throttling of the first throttling device is lowered to reduce the reduced pressure range of the refrigerant.

  In addition, after the compressor is stopped before the start of the defrosting and the refrigerant amount of the first evaporator is increased, the first switching valve is switched to the second condenser side, and the second switching is performed. The compressor was operated with a valve shutting off the flow path to the first evaporator side and the second evaporator side, and the amount of the refrigerant in the piping around the first evaporator was reduced. Thereafter, the second switching valve is switched to the second evaporator side.

  Further, when the defrosting is finished, the flow path to the first evaporator side and the second evaporator side is blocked by the second switching valve while the compressor is operated, and the second evaporation is performed. After reducing the refrigerant amount existing in the pipe on the condenser side, the first switching valve is switched to the first condenser side, and the second switching valve is switched to the first evaporator side.

  Second, in the refrigerator in which the compressor, the first condenser, the heat radiating pipe, the dryer, the two-way valve, the first throttling device, and the first evaporator are connected in order, the compressor is provided in the vicinity of the first evaporator. A second condenser, a second expansion device provided downstream of the second condenser, piping connected to the downstream of the first evaporator through the second evaporator, and to the second condenser side A first switching valve for switching a refrigerant flow, and a high-temperature refrigerant discharged from the compressor at the time of defrosting flows to the second condenser and adheres to the first evaporator by heat conduction of the refrigerant. While the frost is melted, the periphery of the second evaporator is cooled by flowing a low-temperature and low-pressure refrigerant through the second evaporator.

  Further, before starting the defrosting, the flow to the first condenser side and the second condenser side is blocked by the first switching valve while the compressor is operating, and the first After reducing the amount of the refrigerant existing in the pipe from the condenser to the first evaporator, the first switching valve is switched to control the refrigerant to flow to the second condenser side.

  Further, when ending the defrosting, the first switching valve is switched to the first condenser side while the compressor is operating, the two-way valve is closed, and the second evaporation is performed from the second condenser. After the refrigerant amount in the pipe to the vessel is reduced, control is performed to open the two-way valve.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

  FIG. 1 is an external view of a refrigerator-freezer according to an embodiment of the present invention, FIG. 2 is a longitudinal sectional view taken along line XX in FIG. 1, and FIGS. 3, 4, and 5 are refrigeration cycle diagrams according to an embodiment of the present invention. 6 is an external view of a second evaporator according to an embodiment of the present invention, FIG. 7 is a flowchart of refrigerant recovery control before the defrosting operation in Examples 1 and 2, and FIG. 8 is in Examples 1 and 2. FIG. 9 is a flowchart of refrigerant recovery control before the defrosting operation in the third embodiment. FIG. 10 is a flowchart of refrigerant recovery control at the end of the defrosting operation in the third embodiment. FIG.

  As shown in FIG. 1, the refrigerator main body 1 of 1st embodiment has the refrigerator compartment 2, the ice making room 3, the upper freezer compartment 4, the lower freezer compartment 5, and the vegetable compartment 6 from upper direction. The ice making chamber 3 and the upper freezing chamber 4 are provided side by side between the refrigerator compartment 2 and the lower freezing chamber 5. As an example, the refrigerator compartment 2 and the vegetable compartment 6 are storage rooms in a refrigerator temperature zone of approximately 3 to 5 ° C. Further, the ice making room 3, the upper freezing room 4 and the lower freezing room 5 are storage rooms in a freezing temperature zone of approximately −18 ° C.

  The refrigerating room 2 includes, on the front side, refrigerating room doors 2a and 2b with double doors (so-called French type) divided into left and right. The ice making room 3, the upper freezing room 4, the lower freezing room 5, and the vegetable room 6 include a drawer type ice making room door 3a, an upper freezing room door 4a, a lower freezing room door 5a, and a vegetable room door 6a. Further, a seal member (not shown) is provided on the surface of each door on the storage chamber side along the outer edge of each door. When each door is closed, outside air enters the storage chamber, and the storage chamber. Controls cool air leakage.

  As shown in FIG. 2, the outside of the refrigerator main body 1 and the inside of the refrigerator are separated by a heat insulating box 10 formed by filling a foam heat insulating material (foamed polyurethane) between the inner box 1a and the outer box 1b. It has been. Moreover, the heat insulation box 10 of the refrigerator main body 1 is mounted with a plurality of vacuum heat insulating materials 25.

  In the refrigerator main body 1, the refrigerator compartment 2, the upper freezer compartment 4 and the ice making chamber 3 (see FIG. 1, the ice making chamber 3 is not shown in FIG. 2) are adiabatically separated by the upper heat insulating partition wall 51. The lower freezing compartment 5 and the vegetable compartment 6 are separated from each other by the lower heat insulating partition wall 52. Further, as shown in FIG. 5, a horizontal partition 53 is provided in the upper part of the lower freezer compartment 5. The horizontal partition 53 partitions the ice making chamber 3 and the upper freezing chamber 4 and the lower freezing chamber 5 in the vertical direction. In addition, a vertical partition 54 that partitions the ice making chamber 3 and the upper freezing chamber 4 in the left-right direction is provided above the horizontal partition 53.

  The horizontal partition 53 receives a seal member (not shown) provided on the storage room side surface of the lower freezer compartment door 5a together with the front surface of the lower heat insulating partition wall 52 and the front surfaces of the left and right side walls, and receives the lower freezer room 5 and the lower stage. The movement of gas between the freezer compartment door 5a is suppressed. Further, a seal member (not shown) provided on the surface of the ice making room door 3a and the upper freezing room door 4a on the storage room side is provided with a horizontal partition 53, a vertical partition 54, an upper heat insulating partition wall 51, and a refrigerator body 1. By contacting the front surfaces of the left and right side walls, gas movement between each storage chamber and each door is suppressed.

  Since the ice making chamber 3, the upper freezing chamber 4 and the lower freezing chamber 5 are all in the freezing temperature zone, the horizontal partition portion 53 and the vertical partition portion 54 are provided at least for the refrigerator main body 1 in order to receive the seal member of each door. It only needs to be on the front side (see FIG. 2). That is, there may be a movement of gas between the storage chambers in the freezing temperature zone, and there may be a case where the heat insulation section is not provided. On the other hand, in the case where the upper freezer compartment 4 is a temperature switching chamber, it is necessary to make a heat insulation compartment, so the horizontal partition 53 and the vertical partition 54 extend from the front side of the refrigerator body 1 to the rear wall.

  A plurality of door pockets 32 are provided on the storage room side of the refrigerator compartment doors 2a and 2b (see FIG. 2). The refrigerator compartment 2 is provided with a plurality of shelves 36. By the shelf 36, the refrigerator compartment 2 is partitioned into a plurality of storage spaces in the vertical direction.

  As shown in FIG. 2, the upper freezer compartment 4, the lower freezer compartment 5, and the vegetable compartment 6 move in the front-rear direction together with a door provided in front of each storage compartment. Storage containers 3b, 4b, 5b, and 6b are provided, respectively. The ice making room door 3a, the upper freezing room door 4a, the lower freezing room door 5a, and the vegetable room door 6a are each put on a handle portion (not shown) and pulled out to the front side, whereby the storage containers 3b, 4b, 5b, 6b can be pulled out.

  As shown in FIG.2 and FIG.3, the refrigerator of 1st embodiment is provided with the 1st evaporator 7 as a cooling means. The first evaporator 7 (as an example, a fin tube type heat exchanger) is provided in an evaporator storage chamber 8 provided substantially at the back of the lower freezing chamber 5. Further, a blower 9 (propeller fan as an example) is provided as a blowing means in the evaporator storage chamber 8 and above the first evaporator 7. The air cooled by the heat exchange with the first evaporator 7 (hereinafter, the low-temperature air heat-exchanged by the first evaporator 7 is referred to as “cold air”) is blown by the blower 9 into the refrigerator compartment air duct 11 and the freezer compartment. Via the duct 12, it is sent to the respective storage rooms of the refrigerator compartment 2, the vegetable compartment 6, the upper freezer compartment 4, the lower freezer compartment 5, and the ice making room 3. The blown air to each storage room is a first blown air volume control means (refrigerating room damper 20) for controlling the blown air volume to the refrigerated temperature zone chamber, and the second blown air volume for controlling the blown air volume to the freezing temperature zone chamber. It is controlled by the control means (freezer compartment damper 50).

  The air ducts to the refrigerator compartment 2, the ice making room 3, the upper freezer room 4, the lower freezer room 5, and the vegetable room 6 are provided on the back side of each storage room of the refrigerator body 1.

  Specifically, when the refrigerator compartment damper 20 is in the open state and the freezer compartment damper 50 is in the closed state, the cold air is sent to the refrigerator compartment 2 from the outlets 2c provided in multiple stages via the refrigerator compartment air duct 11.

  Note that the cold air that has cooled the refrigerator compartment 2 is blown out from the refrigerator compartment return port 2d provided in the lower part of the refrigerator compartment 2 through the refrigerator compartment return duct 16 and the vegetable compartment provided on the lower right rear side of the lower heat insulating partition wall 52. The air is blown from the mouth 6c to the vegetable compartment 6.

  The return cold air from the vegetable compartment 6 passes through the vegetable compartment return duct 18 from the vegetable compartment return duct inlet 18b provided in front of the lower heat insulating partition wall 52, and passes through the vegetable compartment return duct outlet 18a. Return to the bottom.

  As another configuration, the refrigeration chamber return duct 16 may be returned to the lower right side when viewed from the front of the evaporator storage chamber 8 without communicating with the vegetable chamber 6. As an example in this case, a vegetable room air duct (not shown) is arranged at the front projection position of the refrigerator compartment return duct 16, and the cold air heat-exchanged by the first evaporator 7 is transferred from the vegetable room outlet 6c to the vegetable room. Direct blow to 6

  As shown in FIG. 2, a partition member 13 that partitions each storage chamber and the evaporator storage chamber 8 is provided in front of the evaporator storage chamber 8. The partition member 13 is formed with air outlets 3c, 4c, 5c. When the freezer damper 50 is in the open state, the cold air heat-exchanged by the first evaporator 7 is blown by an air blower 9 into an ice making chamber (not shown). The air is blown from the outlets 3c and 4c to the ice making chamber 3 and the upper freezer compartment 4 through the duct and the upper freezer compartment air duct 12. Further, the air is blown from the outlet 5 c to the lower freezer compartment 5 through the freezer compartment air duct 12.

  Generally, cold air having a low temperature with respect to the ambient temperature forms a downward flow from the upper side to the lower side. Therefore, by supplying more cold air to the upper side of the storage chamber, the storage chamber can be favorably cooled by the action of the downward flow. In the first embodiment, the freezer compartment damper 50 is provided. However, by installing the freezer damper 50 above the blower 9, the air from the blower 9 can be smoothly blown to the ice making chamber 3 and the upper freezer compartment 4. Consideration. If the ice making chamber 3, the upper freezing chamber 4, and the lower freezing chamber 5 are configured to communicate with each other, the cooling effect by the downflow can be enhanced.

  The partition member 13 is provided with a freezer compartment return port 17 at a position in the lower part of the lower freezer compartment 5, and the cold air that has cooled the upper freezer compartment 4, the lower freezer compartment 5, and the ice making chamber 3 is supplied to the freezer compartment return port. It flows into the evaporator storage chamber 8 through 17. The freezer compartment return port 17 has a width dimension substantially equal to the width of the first evaporator 7.

  Next, the refrigeration cycle in the first embodiment will be described. FIG. 3 shows an example of the configuration of the refrigeration cycle in the present invention. The compressor 24, the first three-way valve 14 (first switching valve), the first condenser 23, the heat radiating pipe 26, the dryer 38, and the first capillary tube 40 ( The pressure reducing means, the first throttle device), the second three-way valve 15 (second switching valve), the first evaporator 7, the second condenser 37, and the second evaporator 41 are configured.

  The check valves 28, 29 and 30 prevent the refrigerant from flowing into the unused pipe when switching between the normal operation and the defrosting operation.

  The first three-way valve 14 performs an operation of switching the flow path of the high-temperature and high-pressure refrigerant discharged from the compressor 24 to either the first condenser 23 or the second condenser 37. The second three-way valve 15 performs an operation of switching the flow path of the low-temperature and low-pressure refrigerant that has passed through the first capillary tube 40 to either the first evaporator 7 or the second evaporator 41. Here, the first three-way valve 14 is switched so that the refrigerant flows from the compressor 24 to the first condenser 23 side, and at the same time, the second three-way valve 15 is switched to transfer the refrigerant from the first capillary tube 40 to the first evaporator 7. The case where the compressor 24 is operated by switching is referred to as “normal operation”.

  During normal operation, the refrigerant compressed by the compressor 24 enters a high temperature and high pressure state and flows into the first condenser 23 via the first three-way valve 14. At this time, the flow path to the second condenser 37 side of the first three-way valve 14 is blocked. In the first condenser 23 and the heat radiating pipe 26, the refrigerant exchanges heat with the outside of the refrigerator, is cooled and condensed, and becomes a low temperature state. Thereafter, moisture in the refrigerant is removed by the dryer 38 and flows into the first capillary tube 40. In the first capillary tube 40, the refrigerant exchanges heat with the heat absorption pipe while being decompressed, adiabatically expands to a low temperature and low pressure state, and flows to the first evaporator 7. The refrigerant in the low temperature and low pressure state absorbs heat from the air inside the refrigerator by the first evaporator 7 and evaporates to cool the air inside the refrigerator.

  The refrigerant returns from the first evaporator 7 to the compressor 24 and is compressed again.

  Here, during normal operation, moisture from outside air that enters the cabinet by opening and closing the door and moisture from stored food or the like adheres to the surface of the first evaporator 7 at a low temperature to form frost. When the amount of frost attached increases, the heat exchange performance of the evaporator 5 decreases, and the performance of the refrigerator-freezer is impaired. For this reason, for example, it becomes necessary to remove the frost adhered to the first evaporator 7 by performing defrosting at predetermined time intervals or according to the accumulated time of normal operation.

  The first three-way valve 14 is switched so that the high-temperature high-pressure refrigerant discharged from the compressor 24 flows to the second condenser 37 side, and at the same time, the low-temperature low-pressure refrigerant that has passed through the first capillary tube 40 is changed to the second evaporator. The case where the compressor 24 is operated by switching the second three-way valve 15 so as to flow to the 41 side is referred to as “defrosting operation”.

  During the defrosting operation, the high-temperature and high-pressure refrigerant discharged from the compressor 24 flows to the second condenser 37 side by the first three-way valve 14 and passes through the vicinity of the first evaporator 7. At this time, the flow path to the first condenser 23 side of the first three-way valve 14 is blocked.

  FIG. 4 is an example of the second condenser 37, 16 is a fin of the first evaporator 7, 17 is a pipe of the second condenser 37, and 18 is a pipe of the first evaporator 7. The piping 16 of the second condenser 37 is provided so as to be in contact with the fins of the first evaporator 7.

  The high-temperature and high-pressure refrigerant flows through the second condenser 37 in contact with the fins of the first evaporator 7 and performs defrosting by exchanging heat with the frost. The heat exchange performance is recovered by melting the frost attached to the first evaporator 7.

  At this time, the refrigerant is cooled by frost and becomes liquid. The length and position of the pipe 17 may be adjusted in consideration of the heat radiation amount in the second condenser 37.

  In addition, only the heat radiation from the second condenser 37 takes time for defrosting due to the amount of energy supplied by the compressor 24. Therefore, a heater for defrosting is prepared and used together. At that time, it is efficient to provide the second condenser 37 in a place where it is difficult for the heater heat to reach and defrost. For example, when the defrosting heater is installed at the lower part of the first evaporator 7, if the second condenser 37 is provided at the upper part of the first evaporator 7, the upper part of the first evaporator 7 that is difficult to melt only with the defrosting heater alone. Frost can be melted by the heat radiation of the second condenser 37.

  Further, during the defrosting operation, the low-temperature and low-pressure refrigerant that has passed through the first expansion device 42 flows to the second evaporator 41 side by the second three-way valve 15 and absorbs heat when flowing through the second evaporator 41. At this time, the flow path to the first evaporator 7 side of the second three-way valve 15 is blocked.

  The refrigerant flowing through the second evaporator 41 is in a low-temperature and low-pressure gas-liquid two-phase state and absorbs heat so that the inside of the refrigerator can be cooled. The structure of the second evaporator 41 may be determined by the position and length of the pipe and the presence or absence of aluminum fins depending on the amount of heat released from the second condenser 37.

  Note that when the liquid refrigerant does not sufficiently evaporate in the second evaporator 41, the liquid refrigerant is sucked into the compressor 24, so it is necessary to use a gas-liquid separation tank or the like.

  In addition, since a low-temperature refrigerant flows through the second evaporator 41, dew and frost adhere around the pipe. Therefore, measures against attached dew and frost are necessary. In this embodiment, the piping of the second evaporator 41 is installed on the evaporating dish 12. Since the ambient temperature rises due to the exhaust heat of the compressor 24 and the heat dissipation of the compressor 24 can be assisted, the cooling power in the second evaporator 41 can be used efficiently.

  However, in this embodiment, the second evaporator 41 is installed around the compressor 24. However, the present invention is not limited to this. For example, the second evaporator 41 may be installed in the refrigerator room 2 or the vegetable room 6 and the like. It can also be used for cooling inside.

  Here, before starting the defrosting operation, it is necessary to remove the refrigerant flowing in the pipe from the first three-way valve 14 to the heat radiating pipe 26.

  If the refrigerant remains, the amount of refrigerant flowing in the cycle during the defrosting operation is reduced, the heat release amount in the second condenser 11 and the heat absorption amount in the second evaporator 41 are reduced, and the defrosting capacity is lowered.

  Therefore, first, before starting the defrosting operation, the compressor 24 is stopped, and the refrigerant is concentrated in the first evaporator 7 having a low temperature.

  Next, the first three-way valve 14 is switched to the second condenser 37 side, and compression is performed with the second three-way valve 15 blocking the flow path to the first evaporator 7 side and the second evaporator 10 side. The machine 24 is operated and the refrigerant in the piping around the first evaporator 7 is removed.

  By performing the above operation before the defrosting operation, the refrigerant does not remain outside the cycle during the defrosting operation, so that it is possible to prevent a decrease in the refrigerant amount during the defrosting operation.

  Also, when the defrosting operation is terminated, if the refrigerant remains in the pipes of the second condenser 37 and the second evaporator 41, the efficiency during the normal operation is lowered due to a decrease in the amount of refrigerant in the refrigeration cycle.

  Therefore, when ending the defrosting operation, first, the flow path to the first evaporator 7 side and the second evaporator 41 side is blocked by the second three-way valve 15 while the compressor 24 is operating, and the second The refrigerant present in the pipe on the evaporator 41 side is removed.

  Next, the first three-way valve 14 is switched to the first condenser 23 side, and the second three-way valve 15 is switched to the first evaporator 7 side.

  By performing the above operation at the end of the defrosting operation, the refrigerant does not remain outside the cycle during the normal operation, and thus it is possible to prevent the refrigerant amount from being insufficient during the normal operation.

  The end of the defrosting operation may be determined by providing temperature detection means in the first evaporator 7 and ending the defrosting operation when the first evaporator 7 reaches the set temperature.

  By performing the above control, in the defrosting operation, the frost adhering to the first evaporator 7 is melted by the heat conduction from the high-temperature refrigerant discharged from the compressor 24, and at the same time, the refrigerant after the heat radiation by the second condenser 37. Since it passes through the first capillary tube 40 and enters a low-temperature and low-pressure state as in normal operation and absorbs heat in the second evaporator 41, the periphery of the second evaporator 41 can be cooled while defrosting. Moreover, the defrosting time can be further shortened by using together with the defrosting heater. Since the defrosting time is shortened, less heat energy enters from the outside during defrosting, so less energy is required for cooling the inside when the defrosting operation is completed and the normal operation is started. Therefore, it is possible to provide a highly efficient refrigerator-freezer with power saving and superior defrosting capacity as compared with the prior art.

  FIG. 3 shows a refrigeration cycle diagram of a refrigerator-freezer according to the present invention. This embodiment is different from FIG. 2 in the configuration of the refrigeration cycle. Below, it demonstrates centering on a different part from FIG. In FIG. 3, the same reference numerals as those shown in FIGS. 2 to 3 are the same parts, and perform the same functions.

  In FIG. 3, the first capillary tube 40 of FIG. 2 is used as an expansion valve so that the amount of pressure reduction can be adjusted.

  During the defrosting operation, the refrigerant temperature is lower when the pressure is reduced than during the normal operation, so the amount of pressure reduction is set low.

  Thereby, since the pressure reduction amount appropriately matched with the refrigerant temperature during the defrosting operation can be determined by using the expansion valve, it is possible to operate efficiently during the defrosting.

  FIG. 4 shows a refrigeration cycle diagram of a refrigerator-freezer according to the present invention. This embodiment is different from FIG. 2 in the configuration of the refrigeration cycle. Below, it demonstrates centering on a different part from FIG. In FIG. 4, the same reference numerals as those in FIGS. 2 to 4 are the same parts, and perform the same functions.

  4 does not connect the pipe after passing through the second condenser 37 from the first switching valve 2 of FIG. 2 after the heat radiating pipe 26 but connects the second capillary tube 43 (second throttle device), and then the second evaporation. This is a refrigeration cycle connected after the first evaporator 7 after passing through the vessel 41 and the check valve 30.

  A two-way valve 39 is provided in front of the dryer 38. When the compressor 24 performs intermittent operation, the high-temperature refrigerant in the heat radiating pipe 26 flows into the first evaporator 7 when the operation of the compressor 24 is stopped, thereby preventing an increase in the temperature in the warehouse.

  Here, the case where the first three-way valve is switched so that the refrigerant flows to the first condenser 23 side and the compressor 24 is operated is referred to as “normal operation”.

  The case where the compressor 24 is operated by switching the first three-way valve 14 so that the refrigerant flows to the second condenser 37 side is referred to as “defrosting operation”.

  Since the pressure when the refrigerant flows through the second capillary tube 43 during the defrosting operation is lower than the pressure when the refrigerant flows through the first capillary tube 40 during the normal operation, the second capillary tube 43 is throttled more than the first capillary tube 40. To reduce the amount of decompression.

  Further, like the first embodiment, before starting the defrosting operation, it is necessary to remove the refrigerant flowing in the pipe from the first three-way valve 14 to the first evaporator 7.

  Therefore, the flow path to the first condenser 23 side and the second condenser 37 side is blocked by the first three-way valve 14 while the compressor 24 is operated before defrosting is started, and the first condenser After sufficiently removing the refrigerant present in the piping from 23 to the first evaporator 7, the first three-way valve 14 is switched to the second condenser 37 side.

  By performing the above operation before the defrosting operation, the refrigerant does not remain outside the cycle during the defrosting operation, so that it is possible to prevent the refrigerant amount from being insufficient during the defrosting operation.

  In addition, when the defrosting operation is ended, the first three-way valve 14 is operated while the compressor 24 is operated in order to prevent the refrigerant from remaining in the pipe from the second condenser 37 to the second evaporator 41. After switching to the first condenser 23 side, the two-way valve 39 is closed and the refrigerant in the pipe from the second condenser 9 to the second evaporator 41 is sufficiently removed, and then the two-way valve 39 is opened.

  By performing the above operation at the end of the defrosting operation, the refrigerant does not remain outside the cycle during the normal operation, and thus it is possible to prevent the refrigerant amount from being insufficient during the normal operation.

  By performing the above control, in the defrosting operation, the frost adhering to the first evaporator 7 is melted by the heat conduction from the high-temperature refrigerant discharged from the compressor 24, and at the same time, the refrigerant after the heat radiation by the second condenser 37. Passes through the second capillary tube 43 and enters a low-temperature and low-pressure state and absorbs heat in the second evaporator 41, so that the periphery of the second evaporator 41 can be cooled while defrosting. Moreover, the defrosting time can be further shortened by using together with the defrosting heater. Since the defrosting time is shortened, less heat energy enters from the outside during defrosting, so less energy is required for cooling the inside when the defrosting operation is completed and the normal operation is started. Therefore, it is possible to provide a highly efficient refrigerator-freezer with power saving and superior defrosting capacity as compared with the prior art.

1 Refrigerator body 2 Refrigerated room (refrigerated temperature zone)
3 Ice making room (freezing temperature zone)
4 Upper freezer room (freezing temperature room)
5 Lower freezer compartment (freezing temperature zone)
6 Vegetable room (refrigerated temperature room)
7 First evaporator 9 Blower (Blower unit)
14 First three-way valve (first switching valve)
15 Second three-way valve (second switching valve)
19 Machine room 20 Cold room damper (first air flow control means)
22 Defrost heater 23 First condenser 24 Compressor 26 Radiation pipes 28, 29, 30 Check valve 31 Control board 37 Second condenser 38 Dryer 39 Two-way valve 40 First capillary tube (pressure reducing means, first throttle device) )
41 2nd evaporator 42 1st expansion device 43 2nd capillary tube (pressure reduction means, 2nd expansion device)
50 Freezer compartment damper (second air flow control means)

Claims (9)

  In the refrigerator in which the compressor, the first condenser, the heat radiating pipe, the dryer, the first squeezing device, and the first evaporator are connected in order, the second condenser provided in the vicinity of the first evaporator from the compressor, A pipe connected to the downstream of the heat radiating pipe through the second condenser, and a first switching valve for switching the refrigerant flow to the second condenser side, and the high-temperature refrigerant discharged from the compressor at the time of defrosting A refrigerator which flows into the second condenser and melts frost attached to the first evaporator by heat conduction of the refrigerant.   A second evaporator provided between the downstream of the first throttling device and the downstream of the first evaporator; and a second switching valve for switching the refrigerant flow to the first evaporator side or the second evaporator side 2. The refrigerator according to claim 1, wherein the refrigerant radiated by the second condenser during the defrosting is depressurized by the throttling device and then flowed to the second evaporator.   The refrigerator according to claim 1, wherein a degree of squeezing by the squeezing device is variable.   During normal operation, the first switching valve is switched so that the refrigerant flows from the compressor to the first condenser, and the second switching valve is switched to flow from the first expansion device to the first evaporator. 4. The refrigerator according to claim 3, wherein, when the defrosting is performed, the squeezing degree of the first throttling device is lowered to reduce the decompression width of the refrigerant.   Before the start of the defrosting, the compressor is stopped, and after the refrigerant amount of the first evaporator is increased, the first switching valve is switched to the second condenser side, and the second switching valve is switched to the second switching valve. After operating the compressor in a state where the flow path to the first evaporator side and the second evaporator side is cut off, and reducing the amount of the refrigerant in the pipe around the first evaporator, The refrigerator according to claim 2, wherein the second switching valve is switched to the second evaporator side.   When ending the defrosting, the flow path to the first evaporator side and the second evaporator side is blocked by the second switching valve while the compressor is operating, and the second evaporator side The first switching valve is switched to the first condenser side and the second switching valve is switched to the first evaporator side after reducing the amount of the refrigerant present in the pipe. The refrigerator according to claim 2 or 5.   In a refrigerator in which a compressor, a first condenser, a heat radiating pipe, a dryer, a two-way valve, a first throttling device, and a first evaporator are connected in this order, the second condenser provided in the vicinity of the first evaporator from the compressor And a second expansion device provided downstream of the second condenser, a pipe connected to the downstream of the first evaporator through the second evaporator, and switching the refrigerant flow to the second condenser side A high-temperature refrigerant discharged from the compressor during defrosting to the second condenser, and frost adhering to the first evaporator is melted by heat conduction of the refrigerant. In addition, the refrigerator around the second evaporator is cooled by flowing a low-temperature and low-pressure refrigerant through the second evaporator.   Before starting the defrosting, the flow to the first condenser side and the second condenser side is blocked by the first switching valve while the compressor is operating, and the first condenser After reducing the amount of the refrigerant existing in the pipe from the first evaporator to the first evaporator, the first switching valve is switched to control the refrigerant to flow to the second condenser side. The refrigerator according to claim 7.   When ending the defrosting, the first switching valve is switched to the first condenser side while the compressor is operating, the two-way valve is closed, and the second condenser to the second evaporator. 9. The refrigerator according to claim 7, wherein control is performed to open the two-way valve after reducing the amount of the refrigerant in the pipe.