JP2018185054A - Cooling storage - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cooling storage capable of eliminating frost attached to a heat exchange for cooling, while suppressing increase of power consumption.SOLUTION: A cooling storage includes a compressor 201, a first heat exchanger 202, a second heat exchanger 205 including an upstream-side heat exchange portion 206 and a downstream-side heat exchange portion 207, a first expander 203 connected to the first exchanger and the upstream-side heat exchange portion, a second expander 204 connected to the upstream-side heat exchange portion and the downstream-side heat exchange portion, and a switching portion 208, and cools a storage chamber by the second heat exchanger. A fist flow channel is configured by the compressor, the first heat exchanger, the first expander, the upstream-side heat exchange portion, and the downstream-side heat exchange portion, a second flow channel is configured by the compressor, the first heat exchanger, the upstream-side heat exchange portion, the second expander, and the downstream-side heat exchange portion, and the switching portion switches the first flow channel and the second flow channel.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a refrigerator that cools the inside of a storage room such as a refrigerator or a freezer and that can defrost a heat exchanger.

  Some conventional refrigerators include a refrigerator room, an ice making room, an upper freezer room, a lower freezer room, and a vegetable room from above. In the conventional refrigerator, a cooler is provided in a cooler housing chamber provided substantially at the back of the lower freezer compartment. The cooler that has exchanged heat with the cooler by the internal fan provided above the cooler passes through the refrigerator compartment, the upper freezer compartment cooler duct, the lower freezer compartment air duct, and the ice making compartment blower duct through the refrigerator compartment, upper stage It is sent to the freezer compartment, the lower freezer compartment, and the ice compartment. The refrigerator is provided with a cooler and a defrosting heater that defrosts the frost that has grown in the cooler storage chamber in the periphery thereof (for example, Patent Document 1).

Japanese Patent Laying-Open No. 2015-007510

  However, in the conventional refrigerator, in addition to the electric power for generating the cold air exchanged with the cooler, the electric power for operating the defrost heater is also necessary, and it is difficult to save power.

  Then, this invention solves the above subjects, and it aims at providing the refrigerator which can suppress the increase in power consumption and can remove the frost adhering to the heat exchanger for cooling.

  Exemplary embodiments of the present invention include a compressor, a first heat exchanger, a second heat exchanger including an upstream heat exchanger and a downstream heat exchanger, the first heat exchanger, and the upstream. A first expander connected to the side heat exchange unit, a second expander connected to the upstream heat exchange unit and the downstream heat exchange unit, and a switching unit. A refrigerator that is cooled by a second heat exchanger, wherein a first flow path is formed by the compressor, the first heat exchanger, the first expander, the upstream heat exchange unit, and the downstream heat exchange unit. And the compressor, the first heat exchanger, the upstream heat exchange unit, the second expander, and the downstream heat exchange unit form a second flow path, and the switching unit is the first flow A path and the second flow path are switched.

  According to an exemplary embodiment of the present invention, heating the second heat exchanger used as an evaporator at the time of the first flow path can be performed only by switching the switching unit without using an electric heater. it can. Thereby, the increase in power consumption can be suppressed and the frost adhering to the heat exchanger for cooling can be removed.

FIG. 1 is a cross-sectional view of a refrigerator according to the present invention. FIG. 2 is a piping diagram during the cooling operation of the cooling device provided in the refrigerator according to the present invention. FIG. 3 is a schematic perspective view of an example of a second heat exchanger used in the cooling device according to the present invention. FIG. 4 is a schematic side view of an example of the upstream heat exchange unit provided in the second heat exchanger shown in FIG. 3. FIG. 5 is a piping diagram during a defrosting operation of the cooling device provided in the refrigerator according to the present invention. FIG. 6 is a perspective view of another example of the second heat exchanger used in the cooling device according to the present invention. FIG. 7 is a perspective view of still another example of the second heat exchanger used in the cooling device according to the present invention. FIG. 8 is a perspective view of still another example of the second heat exchanger used in the cooling device according to the present invention. FIG. 9 is a perspective view of still another example of the second heat exchanger used in the cooling device according to the present invention. FIG. 10 is a piping diagram during cooling operation of another example of the cooling device according to the present invention. FIG. 11 is a piping diagram during the defrosting operation of the cooling device shown in FIG. 10. FIG. 12 is a piping diagram during cooling operation of still another example of the cooling device according to the present invention. FIG. 13 is a piping diagram during the defrosting operation of the cooling device shown in FIG. 12.

Hereinafter, exemplary embodiments of the present invention will be described with reference to the drawings.
<Overall configuration of refrigerator>
FIG. 1 is a cross-sectional view of a refrigerator according to the present invention. In the following description, the front side (left side in FIG. 1) of the refrigerator Rf shown in FIG. Moreover, right and left are defined with respect to the front of the refrigerator Rf shown in FIG. In addition, with respect to the refrigerator Rf shown in FIG. In the following description, the shape and positional relationship of each part will be described using the front-rear direction, the left-right direction, and the up-down direction. However, the definition of this direction is not intended to limit the direction of the refrigerator according to the present invention.

  The refrigerator Rf shown in FIG. 1 includes a box 1 and a cooling device 2. The box 1 is a heat insulating box whose wall is filled with a heat insulating material. The front side of the box 1 is open. The cooling device 2 is disposed inside the box 1.

  In the box 1, a freezer compartment 102 and a refrigerator compartment 103 are formed by partitioning an internal space vertically by a plate-shaped partition shelf filled with a heat insulating material. A door 104 is provided in front of the freezer compartment 102. A door 105 is provided in front of the refrigerator compartment 103. Both the door 104 and the door 105 are filled with a heat insulating material as in the case of the box 1. The door 104 and the door 105 are one-sided doors in which the left and right ends in the left-right direction are rotatably supported when viewed from the front side. The door 104 and the door 105 open and close the freezer compartment 102 and the refrigerator compartment 103, respectively.

  The configuration of the doors 104 and 105 is not limited to this. For example, as a configuration of the doors 104 and 105, a door provided with a support portion that can be rotated at both ends, a door that rotates both left and right from the central portion, and a door that slides in the front-rear direction (so-called slide door) may be employed. . Furthermore, as a structure of the doors 104 and 105, the structure which can open and close the freezer compartment 102 and the refrigerator compartment 103 can be employ | adopted widely.

  The freezer compartment 102 is a storage compartment in which the stored items can be stored frozen (for example, stored at −18 ° C.). The refrigeration room 103 is a storage room for storing stored items in a refrigerator at a higher temperature (for example, 3 ° C. to 5 ° C.) than the freezing room 102. In addition, the temperature of each store room is not limited to this, You may set to the temperature which can suppress deterioration of the articles | goods stored in each store room. Further, the user may be able to set the temperature as required or according to his / her preference.

  A partition wall 106 is provided on the rear side of the freezer compartment 102 and the refrigerator compartment 103. A first duct 107 is provided on the opposite side of the freezer compartment 102 across the partition wall 106. A second duct 108 is provided on the opposite side of the refrigerator compartment 103. The first duct 107 and the second duct 108 are in communication. A first damper 109 is provided at the same height as the partition shelf 101. The first damper 109 opens and closes by rotating around the axis. When the first damper 109 is in the open state, the first duct 107 and the second duct 108 are in communication. When the first damper 109 is in the closed state, the first duct 107 and the second duct 108 are partitioned.

  The partition wall 106 is provided with a blowout port 112, a return port 113, and a return port 115. The blowout port 112 and the return port 113 are through holes that allow the freezer compartment 102 and the first duct 107 to communicate with each other. The outlet 112 communicates with the upper part of the freezer compartment 102. The return port 113 communicates with the lower part of the freezer compartment 102. Note that when the first damper 109 is in the open state, the return opening 113 is closed by the first damper 109. The return port 115 is a through hole that communicates between the refrigerator compartment 103 and the second duct 108, and communicates with the lower portion of the refrigerator compartment 103.

  The partition shelf 101 is provided with a ventilation duct 114 and a second damper 111. The ventilation duct 114 is a duct that allows the freezer compartment 102 and the refrigerator compartment 103 to communicate with each other. The second damper 111 is a damper that opens and closes the ventilation duct 114. When the second damper 111 is in the open state, the freezer compartment 102 and the refrigerator compartment 103 are in communication with each other via the ventilation duct 114. When the second damper 11 is in the closed state, the freezer compartment 102 and the refrigerator compartment 103 are partitioned.

  Inside the first duct 107, an upstream heat exchange unit 206, which will be described later, of the cooling device 2 and a second heat exchanger 205 including a downstream heat exchange unit 207 are arranged. A fan 110 is disposed above the second heat exchanger 205. The fan 110 is disposed on the upper part of the second heat exchanger 205. The fan 110 causes the airflow that flows above the inside of the first duct 107 to flow to the second heat exchanger 205 side. In addition, the fan 110 is arrange | positioned above the 2nd heat exchanger 205, and the flooding to the electrical equipment part of the fan 110 by the defrost water (namely, drain water) generate | occur | produced at the time of the defrost operation mentioned later is suppressed. be able to. Furthermore, failure and breakage of the fan 110 can be suppressed.

  In addition, the cooling device 2 includes a machine room 116 formed between the refrigerator compartment 103 and a heat insulating wall (not shown) below the back side of the refrigerator Rf. Inside the machine room 116, a part of members constituting the cooling device 2 such as the compressor 201 is disposed.

<About cooling the inside of the refrigerator>
Next, cooling of the freezer compartment 102 and the refrigerator compartment 103 will be described. Although details will be described later, the cooling device 2 includes a cooling operation for cooling only the freezer compartment 102 or both the freezer compartment 102 and the refrigerator compartment 103, and a defrosting operation for removing frost adhering to the second heat exchanger 205. It can be carried out. Here, the case where the cooling device 2 is cooled and the freezer compartment 102 and the refrigerator compartment 103 are cooled will be described.

  In the refrigerator Rf, the second heat exchanger 205 is used as a cooler. A low-temperature refrigerant flows inside the second heat exchanger 205. The refrigerant exchanges heat with the air outside the second heat exchanger 205 to cool the outside air. By flowing this cooled air (hereinafter sometimes referred to as cold air), the freezer compartment 102 and the refrigerator compartment 103 are cooled. In the refrigerator Rf, only the freezer compartment 102 can be cooled, and the freezer compartment 102 and the refrigerator compartment 103 can be cooled. In the following description of cooling, it is assumed that the cooling device 2 performs a cooling operation using the second heat exchanger 205 as a cooler (that is, an evaporator).

  A case where only the freezer compartment 102 is cooled will be described. In order to allow cold air to flow only in the freezer compartment 102, first, the first damper 109 and the second damper 111 are closed. By closing the first damper 109, the first duct 107 and the second duct 108 are partitioned, and the return port 113 is opened. Moreover, the freezer compartment 102 and the refrigerator compartment 103 are partitioned by making the 2nd damper 111 into a closed state. When the fan 110 is driven in this state, the cold air generated by the second heat exchanger 205 ascends the first duct 107 and blows out from the outlet 112 to the freezer compartment 102.

  The cold air that has flowed into the freezer compartment 102 flows inside the freezer compartment 102. At this time, the inflowing cool air takes heat from the air and stored items inside the freezer compartment 102 and cools the inside of the freezer compartment 102. The cold air flowing through the freezer compartment 102 returns from the return port 113 to the first duct. The temperature of the cold air is raised by the heat taken when cooling the air and stored items in the freezer compartment 102 and is cooled again by the second heat exchanger 205.

  As described above, the cooling device 2 operates using the second heat exchanger 205 as a cooler, and closes the first damper 109 and the second damper 111 and drives the fan 110, so that only the freezer compartment 102 is placed. Can be cooled.

  When cooling the freezer compartment 102 and the refrigerator compartment 103, the 1st damper 109 and the 2nd damper 111 are made into an open state. By opening the 1st damper 109, the 1st duct 107 and the 2nd duct 108 will be in a communication state. Further, the return port 113 is closed by opening the first damper 109. By opening the 2nd damper 111, the ventilation duct 114 opens and the freezer compartment 102 and the refrigerator compartment 103 will be in a communication state.

  When the fan 110 is driven in this state, the cold air generated by the second heat exchanger 205 flows through the inside of the freezer compartment 102 from the outlet 112 and cools the air and stored items inside the freezer compartment 102. To do. Then, the cold air flows into the refrigerator compartment 103 through the ventilation duct 114. The cold air flows through the refrigerating chamber 103 to cool the air and stored items inside the refrigerating chamber 103.

  Note that switching between cooling of only the freezer compartment 102 and cooling of the freezer compartment 102 and the refrigerator compartment 103 is performed by, for example, the indoor temperature or the outside air temperature detected by the temperature sensor provided in the freezer compartment 102 and the refrigerator compartment 103, the door This is performed based on information such as opening / closing frequency. However, switching between cooling only the freezer compartment 102 and cooling both the freezer compartment 102 and the refrigerator compartment 103 is not limited to this.

  The freezer compartment 102 and the refrigerator compartment 103 are provided with a door 104 and a door 105. When a user stores an article in at least one of the freezer compartment 102 and the refrigerator compartment 103, or when taking out an article stored from at least one of the refrigerator compartment 102 or the refrigerator compartment 103, At least one of the door 104 and the door 105 is opened and closed. When the door 104 is opened and closed, air that is hotter than the air inside the freezer compartment 102 flows into the freezer compartment 102. When the door 105 is opened and closed, air having a temperature higher than that of the air inside the refrigerator compartment 103 flows into the refrigerator compartment 103. In general, the higher the temperature, the greater the amount of water vapor contained in air. Therefore, when external air having a high temperature flows into at least one of the freezer compartment 102 and the refrigerator compartment 103, moisture also flows in together, and the humidity (relative humidity) of the air inside the refrigerator compartment 102 and the refrigerator compartment 103 is increased. Rises.

  When air with high humidity comes into contact with the second heat exchanger 205 during the cooling operation, moisture contained in the air condenses on the second heat exchanger 205, and the condensation is further cooled and frozen to form the second heat as frost. It adheres to the exchanger 205. When frost adheres to the second heat exchanger 205, the efficiency of heat exchange performed between the refrigerant of the second heat exchanger 205 and the surrounding air decreases. Therefore, the cooling device 2 performs a defrosting operation for melting the frost of the second heat exchanger 205. Although details will be described later, when the defrosting operation is performed in the cooling device 2, the second heat exchanger 205 is heated with the heat of the refrigerant to melt and remove the frost. In addition, a drainage part is provided in the lower part of the 2nd heat exchanger 205 of the refrigerator Rf (illustration omitted). The drainage part drains defrost water (drain water) generated by melting of frost to the outside of the box 1.

(First embodiment)
<Configuration of cooling device>
Next, the cooling device 2 provided in the refrigerator Rf will be described with reference to the drawings. FIG. 2 is a piping diagram during the cooling operation of the cooling device provided in the refrigerator according to the present invention. The refrigerator Rf has a cooling device 2. More specifically, the cooling device 2 includes a compressor 201, a first heat exchanger 202, a second heat exchanger 205, a first expander 203, a second expander 204, and a switching unit 208. In the cooling device 2, the compressor 201, the first heat exchanger 202, the first expander 203, the second expander 204, the second heat exchanger 205, and the switching unit 208 are connected by piping. The cooling device 2 is a heat pump that encloses a refrigerant and takes out cold heat (that is, generates cold air) by changing the phase of the refrigerant into a gas or a liquid.

  The second heat exchanger 205 includes an upstream heat exchange unit 206 and a downstream heat exchange unit 207. Detailed structures of the upstream heat exchange unit 206 and the downstream heat exchange unit 207 will be described later. As shown in FIG. 2, in the cooling device 2, the compressor 201, the first heat exchanger 202, the first expander 203, the upstream heat exchange unit 206, the second expander 204, and the downstream heat exchange unit 207 They are connected in series by piping. That is, the refrigerator Rf is connected to the first expander 203 connected to the first heat exchanger 202 and the upstream heat exchange unit 206, and to the upstream heat exchange unit 206 and the downstream heat exchange unit 207. A second inflator 204.

  The switching unit 208 includes a first on-off valve 209 and a second on-off valve 210. A branch b11 is provided in the pipe between the first heat exchanger 202 and the first expander 203. A branch b <b> 12 is provided in the pipe between the first expander 203 and the upstream heat exchange unit 206. A pipe that connects these branches b11 and b12, that is, bypasses the first expander 203 is provided, and a first on-off valve 209 is provided to open and close the pipe.

  Further, a branch b <b> 21 is provided in the pipe between the upstream heat exchange unit 206 and the second expander 204. A pipe b between the second expander 204 and the compressor 201 is provided with a branch b22. A pipe that connects these branches b21 and b22, that is, bypasses the second expander 204 is provided, and a second on-off valve 210 is provided to open and close the pipe. Although details will be described later, the switching unit 208 is a refrigerator Rf that switches between the first flow path Cp1 and the second flow path Cp2.

  The compressor 201 includes an electric motor, compresses the refrigerant, and sends the compressed refrigerant to a first heat exchanger 202 connected in series with a pipe. The compressor 201 is disposed inside the machine room 116. The first heat exchanger 202 is used as a condenser. In other words, the first heat exchanger 202 cools and liquefies (that is, condenses) by exchanging heat with the external air from the refrigerant sent from the compressor 201. The 1st heat exchanger 202 is comprised by piping routed facing the outer surface of the side wall of the box 1 of the refrigerator Rf. As the refrigerant passes through the pipe, the heat of the refrigerant is discharged to the outside of the refrigerator Rf.

  By setting it as such a structure, the dew condensation on the wall surface of the refrigerator Rf can be prevented. The first heat exchanger 202 is preferably made of a metal such as copper having a high thermal conductivity. Thereby, in the 1st heat exchanger 202, the efficiency of the heat exchange performed between a refrigerant | coolant and external air can be improved. Moreover, as a metal used for the 1st heat exchanger 202, metals with high heat conductivity, such as aluminum (alloy), may be used besides copper. In addition, as a structure of the 1st heat exchanger 202, it is not limited to this structure, An air cooling type or a water cooling type heat exchanger may be sufficient.

  The first expander 203 and the second expander 204 adiabatically expand the liquid refrigerant. In the present embodiment, capillary tubes are used as the first expander 203 and the second expander 204. However, the first expander 203 and the second expander 204 are not limited to this, an expansion valve may be used, and other devices that can expand the refrigerant may be used. . Note that both the first expander 203 and the second expander 204 may have the same configuration (for example, a configuration having the same throttle amount), or may have different configurations.

  For example, the first expander 203 is mainly used when cooling the storage chamber, and is preferably capable of generating a large pressure difference with respect to the refrigerant, that is, having a large throttle amount. Further, the second expander 204 only needs to be able to generate a pressure difference necessary for evaporating (that is, vaporizing) the refrigerant returning to the compressor 201. The pressure difference with respect to the refrigerant may be smaller than that of the first expander 203. In other words, the throttle amount of the second expander 204 may be smaller than the throttle amount of the first expander 203. In a capillary tube, examples of a method for adjusting the expansion capacity include, but are not limited to, changing the inner diameter and changing the length.

  The switching unit 208 will be described. In the drawings in the following description, a white open / close valve is shown open, and a black filled open / close valve is shown closed. That is, in the cooling device Rf shown in FIG. 2, the black-colored first on-off valve 209 is closed, and the white second on-off valve 210 is open.

  When the first on-off valve 209 is closed, no refrigerant flows through the first on-off valve 209. The first on-off valve 209 has smaller flow resistance (that is, pressure loss of the flow path through which the refrigerant flows) than the first expander 203, and the refrigerant flows through the first on-off valve 209 when the first on-off valve 209 is open. . That is, when the first on-off valve 209 is closed, the refrigerant flows into the first expander 203 from the branch b11. On the other hand, when the first on-off valve 209 is opened, all or most of the refrigerant flows from the branch b11 into the first on-off valve 209 having a small flow path resistance. That is, the first on-off valve 209 is opened and closed to control the refrigerant to flow into the first expander 203 from the first heat exchanger 202, or the first heat expander 203 is bypassed and the upstream heat exchange unit 206 is bypassed. Can be controlled.

  Similarly, when the second on-off valve 210 is closed, no refrigerant flows into the second on-off valve 210. The second on-off valve 210 has a smaller flow resistance (that is, pressure loss of the flow path through which the refrigerant flows) than the second expander 204, and the refrigerant flows through the second on-off valve 210 when the second on-off valve 210 is open. . That is, when the second on-off valve 210 is closed, the refrigerant flows into the second expander 204 from the branch b21. On the other hand, when the second on-off valve 210 is opened, all or most of the refrigerant flows from the branch b21 into the second on-off valve 210 having a small flow path resistance. That is, the second on-off valve 210 is opened and closed to control the refrigerant to flow into the second expander 204 from the upstream heat exchange unit 206, or the second expander 204 is bypassed and the downstream heat exchange unit 207 is bypassed. Can be controlled.

  Further, in the refrigerator Rf, the switching unit 208 is arranged in parallel with the first expander 203 and has a first on-off valve 209 having a flow path resistance lower than that of the first expander 203 and a second open valve 209 when in the open state. The second on-off valve 210 is disposed in parallel with the expander 204 and has a lower flow path resistance than the second expander 204 when in the open state.

  The opening / closing control of the first opening / closing valve 209 and the second opening / closing valve 210 is performed based on a control signal from a control circuit (not shown).

<Configuration of second heat exchanger>
Next, the details of the second heat exchanger will be described. As shown in FIG. 2, in the cooling device 2 according to the present invention, the second heat exchanger 205 is configured by combining an upstream heat exchange unit 206 and a downstream heat exchange unit 207. Here, the second heat exchanger 205 will be described with reference to the drawings. FIG. 3 is a schematic perspective view of an example of a second heat exchanger used in the cooling device according to the present invention. FIG. 4 is a schematic side view of an example of the upstream heat exchange unit provided in the second heat exchanger shown in FIG. 3.

  As shown in FIG. 3, the second heat exchanger 205 includes an upstream heat exchange unit 206 and a downstream heat exchange unit 207 disposed above the upstream heat exchange unit 206. That is, the downstream heat exchange unit 207 is disposed above the upstream heat exchange unit 206. In the cooling device 2 of the present embodiment, the configuration of the upstream heat exchange unit 206 is the same as the configuration of the downstream heat exchange unit 207. Here, the upstream heat exchange unit 206 will be described as a representative. In addition, the magnitude | size of the upstream heat exchange part 206 may be the same as the magnitude | size of the downstream heat exchange part 207, and may differ.

  As shown in FIG. 4, the upstream heat exchange unit 206 is a plate fin tube type heat exchanger. The upstream heat exchange unit 206 includes a refrigerant pipe 260 and a plurality of fins 261 that are parallel to each other and extend in the vertical direction (V direction in the drawing). The refrigerant pipe 260 has a straight part and a curved part. The refrigerant pipe 260 has a shape in which a straight portion and a curved portion are combined, that is, a meandering shape. Thus, since the shape of the refrigerant | coolant pipe | tube 260 is a meandering shape, the volume in which the refrigerant | coolant flows in in the refrigerant | coolant pipe | tube 260 can be enlarged.

  The refrigerant pipe 260 penetrates the fin 261 at a straight portion and is fixed to the fin 261. The refrigerant pipe 260 and the fins 261 are formed of a material having high thermal conductivity (for example, copper, aluminum, or an alloy thereof). Since the shape of the refrigerant pipe 260 is a meandering shape, it is possible to ensure a wide area (that is, an area in contact) where the refrigerant pipe 260 is fixed to the fins 261. Thereby, the amount of heat transfer between the refrigerant pipe 260 and the fin 261 can be increased, and the refrigerant pipe 260 and the fin 261 have the same or substantially the same temperature.

  Therefore, when heat exchange is performed between the refrigerant in the refrigerant pipe 260 and the external air, the air exchanges heat not only in the part in contact with the refrigerant pipe 260 but also in the part in contact with the fins 261 (that is, Cooling). For these reasons, the upstream heat exchanging unit 206 can increase the area in contact with the air, and the heat exchange performed between the refrigerant flowing inside the upstream heat exchanging unit 206 and the external air is efficient. Can be done well. That is, during the cooling operation of the cooling device 2, the upstream heat exchange unit 206 can generate a large amount of cold air.

  The refrigerant pipe 260 includes an inlet 262 into which refrigerant flows and an outlet 263 from which refrigerant flows out. As shown in FIGS. 3 and 4, in the upstream heat exchange unit 206, the inflow port 262 is provided in the lower part of the upstream heat exchange unit 206. In addition, the outlet 263 is provided at the upper part of the upstream heat exchange unit 206.

  Note that the upstream heat exchange unit 206 is not limited to this shape. For example, the refrigerant pipe 206 may be configured such that both the inlet and the outlet are provided at the upper part of the refrigerant pipe 206 and have a portion that is folded back at the lower part of the refrigerant pipe 206. The heat exchanger is not particularly limited as long as it can effectively exchange heat using a refrigerant.

  The configuration of the downstream heat exchange unit 207 is the same as the configuration of the upstream heat exchange unit 206. Although details are omitted, as shown in FIG. 3, the downstream heat exchange unit 207 includes a refrigerant pipe (not shown), a plurality of fins 271, an inlet 272, and an outlet 273.

<Operation of cooling device>
The cooling operation and defrosting operation of the cooling device 2 will be described with reference to the drawings. FIG. 5 is a piping diagram during a defrosting operation of the cooling device provided in the refrigerator according to the present invention. The cooling device 2 performs switching between a cooling operation for cooling the freezer compartment 102 and the refrigerator compartment 103 of the refrigerator Rf and a defrosting operation for removing frost attached to the second heat exchanger 205.

  First, the cooling operation will be described. When the cooling device 2 is cooled, as shown in FIG. 2, the cooling device 2 closes the first on-off valve 209 and opens the second on-off valve 210. Thereby, in the cooling device 2, the compressor 201, the first heat exchanger 202, the first expander 203, the upstream heat exchange unit 206, and the downstream heat exchange unit 207 are connected in order by piping. One flow path Cp1 is configured. In this embodiment, each of the upstream heat exchange unit 206 and the downstream heat exchange unit 207 is an evaporator.

  In the cooling device 2, when the first flow path Cp <b> 1 is configured, the gaseous refrigerant is compressed by the compressor 201 to become a high-temperature and high-pressure gaseous refrigerant (gas). The high-temperature and high-pressure gaseous refrigerant flows into the first heat exchanger 202. The first heat exchanger 202 functions as a condenser. The first heat exchanger 202 cools and condenses the high-temperature and high-pressure gaseous refrigerant. In other words, the first heat exchanger 202 exchanges heat of the refrigerant with the outside air, and condenses the gaseous refrigerant. In the first heat exchanger 202, the heat of the refrigerant is released to the outside of the refrigerator Rf.

  As described above, since the first on-off valve 209 is closed, the high-pressure liquid refrigerant condensed in the first heat exchanger 202 flows into the first expander 203 from the branch b11. The first inflator 203 uses a capillary tube. In the first expander 203, the high-pressure liquid refrigerant is decompressed to become a low-pressure liquid refrigerant. In the 1st expander 203, a refrigerant | coolant is pressure-reduced rapidly as it expand | swells rapidly. Then, the decompressed liquid refrigerant flows into the upstream heat exchange unit 206 from the inlet 262.

  The decompressed liquid refrigerant evaporates (that is, vaporizes) inside the upstream heat exchange unit 206. That is, when the 1st flow path Cp1 is comprised in the cooling device 2, the upstream heat exchange part 206 functions as an evaporator (namely, cooler). The liquid refrigerant takes heat of vaporization from the surrounding air when it evaporates (that is, vaporizes) in the upstream heat exchange unit 206, that is, the refrigerant exchanges heat with the air around the upstream heat exchanger 206. Thereby, cold air is generated in the upstream heat exchange unit 206. Then, air can be continuously sent to the upstream heat exchange unit 206 by generating an air flow with the fan 110. As a result, cool air is generated stably and continuously. From the above, the cold air generated by the second heat exchanger 205 enters the storage room, and the storage is cooled. That is, the storage room is cooled by the second heat exchanger 205.

  By adjusting at least one of the throttle amount of the first expander 203 and the refrigeration capacity of the upstream heat exchange unit 206, the temperature of the cold air generated in the upstream heat exchange unit 206 is It becomes the temperature which can be cooled. The temperature at which the freezer compartment 102 can be cooled is lower than the freezing temperature (eg, −18 ° C.) of the freezer compartment 102 (eg, −25 ° C.).

  As described above, the second on-off valve 210 is open. For this reason, all or most of the refrigerant that has flowed out of the upstream heat exchange unit 206 by opening the outlet 263 has a flow resistance (that is, pressure of the flow path through which the refrigerant flows) from the branch b21 rather than the second expander 204. Loss) is passed through the second on-off valve 210 and flows into the downstream heat exchange section 207 from the inlet 272. The gaseous refrigerant evaporated in the upstream heat exchange unit 206 passes through the downstream heat exchange unit 207 and returns to the compressor 201 from the outlet 273.

  The decompressed liquid refrigerant that has not evaporated in the upstream heat exchange unit 206 may flow into the downstream heat exchange unit 207. The reduced-pressure liquid refrigerant that has flowed in evaporates in the downstream heat exchange section 207. Even when the liquid refrigerant evaporates in the downstream heat exchange unit 207, the refrigerant exchanges heat with the air around the downstream heat exchange unit 207 as in the upstream heat exchange unit 206. In other words, heat is taken from the air around the downstream heat exchange unit 207. Thereby, cold air is generated in the downstream heat exchange section 207.

  The ratio of the gaseous refrigerant and the liquid refrigerant flowing into the downstream heat exchange unit 207 depends on the refrigeration capacity of the upstream heat exchange unit 206 (for example, capacity, fin size, number of fins, etc.). Change. Even if the ratio of the gaseous refrigerant and the liquid refrigerant is large, the downstream heat exchanging unit 207 has an evaporation capability capable of returning the gaseous refrigerant from the outlet 273 to the compressor 201.

  In the cooling device 2, when the first flow path Cp1 is configured, the second heat exchanger 205 functions as an evaporator, in other words, a cooler. That is, the upstream heat exchange unit 206 or the upstream heat exchange unit 206 and the downstream heat exchange unit 207 function as an evaporator (in other words, a cooler). That is, in the cooling device 2, when the first on-off valve 209 is closed and the second on-off valve 210 is opened to configure the first flow path Cp1, the compressor 201 is driven to perform the cooling operation. Become.

  During the cooling operation, air is passed between the fins 261 and 271 of the second heat exchanger 205 so that heat exchange between the refrigerant flowing inside the second heat exchanger 205 and the outside air (that is, Air cooling) is performed efficiently. In other words, in the second heat exchanger 205, cold air is efficiently generated by flowing air between the fins 261 and 271.

  Next, the defrosting operation will be described. As described above, in the refrigerator Rf, the humidity in the air in the refrigerator Rf increases due to the inflow of outside air due to the opening and closing of the door 104 and the door 105, evaporation from stored items, and the like. And if the operation period of the refrigerator Rf becomes long, the water | moisture content in air will adhere to the 2nd heat exchanger 205 as frost (namely, it forms frost).

  However, when the second heat exchange 205 is frosted, the fins 261 and 271 are clogged, and the amount of air flowing between the fins 261 and 271 is reduced. When the amount of air flowing between the fins 261 and 271 decreases, heat exchange (that is, cooling of the air) performed between the refrigerant and external air becomes difficult to be performed efficiently. That is, it is difficult for the second heat exchanger 205 to generate cold air.

  Therefore, the cooling device 2 can perform a defrosting operation for removing frost attached to the second heat exchanger 205. In addition, although frost formation mainly generate | occur | produces in the upstream heat exchange part 206, it may generate | occur | produce also in the downstream heat exchange part 207.

  When the cooling device 2 is defrosted, as shown in FIG. 5, the first on-off valve 209 is opened and the second on-off valve 210 is closed. Thereby, in the cooling device 2, the compressor 201, the 1st heat exchanger 202, the upstream heat exchange part 206, the 2nd expander 204, and the downstream heat exchange part 207 were connected in series in order by piping. A second flow path Cp2 is configured. In the cooling device 2, when the second flow path Cp <b> 2 is configured, the fan 110 is stopped, and no airflow is generated by the fan 110 in the first duct 107 and the cooling duct 108.

  In the cooling device 2, when the second flow path Cp2 is configured, the flow path from the compressor 201 to the first heat exchanger 202 is when the first flow path Cp1 is configured in the refrigerant flow path 2. The configuration is the same. That is, the high-temperature and high-pressure gaseous refrigerant compressed by the compressor 201 flows into the first heat exchanger 202. In the first heat exchanger 202, the high-temperature and high-pressure gaseous refrigerant is condensed by heat exchange and becomes a liquid refrigerant.

  In the cooling device 2, when the second flow path Cp2 is configured, the first on-off valve 209 is open. Therefore, all or most of the refrigerant flows into the first on-off valve 209 from the branch b11. And a refrigerant | coolant flows in into the upstream heat exchange part 206 with a liquid state. The liquid refrigerant flowing into the upstream heat exchange unit 206 has a high pressure because it does not pass through the expander. Therefore, the liquid refrigerant does not evaporate even when it flows into the upstream heat exchange unit 206. The refrigerant is cooled and condensed by the first heat exchanger 202. However, the temperature of the refrigerant is higher than the melting point of water.

  Liquid refrigerant is supplied directly from the first heat exchanger 202 to the upstream heat exchange unit 206 via the first on-off valve 209. Thereby, a liquid refrigerant performs heat exchange with the frost adhering to the refrigerant | coolant pipe | tube 260 and the fin 261 of the upstream heat exchange part 206, ie, heats frost and melts frost.

  That is, in the refrigerator Rf, the first flow path Cp1 is configured during cooling, and the second flow path Cp2 is configured during defrosting. When the first flow path Cp1 is configured, the first on-off valve 209 is closed and the second on-off valve 210 is opened. Further, when the second flow path Cp2 is configured, the first on-off valve 209 is opened and the second on-off valve 210 is closed.

  In the refrigerant pipe 260 and the fin 261 of the upstream heat exchange unit 206, defrost water (that is, drain water) due to frost melting is generated. In the upper heat exchanger 206, the fins 261 extend in the vertical direction and are arranged in parallel in the horizontal direction. Therefore, the drain water flows downward along the fins 261. A drainage unit (not shown) is provided below the upstream heat exchange unit 206. The drain water is discharged to the outside of the refrigerator Rf through the drainage part.

  Further, in the upstream heat exchange unit 206, the liquid refrigerant exchanges heat with frost attached to the refrigerant pipe 260 and the fins 261, and also exchanges heat with external air. Thereby, the air around the upstream heat exchange unit 206 is heated. Even if the fan 110 is stopped, the air heated by the upstream heat exchange unit 206 flows upward. Even when the heated air flows upward, the fins 261 are unlikely to obstruct the air flow. Note that the heated air (hot air) flows toward the downstream heat exchange unit 207 disposed above the upstream heat exchange unit 206.

  In the downstream heat exchange unit 207, when high-temperature air flows between the fins 271, the attached frost is heated to melt the frost. The drain water generated at this time also flows downward through the fins 271. The drain water generated in the downstream heat exchange unit 207 may further flow through the fins 261 of the upstream heat exchange unit 206 and flow into the drainage unit, or may be directly drained by another structure. It may come to flow into.

  The high-temperature air that has flowed into the downstream heat exchange section 207 is deprived of heat when frost is melted, and the temperature is lowered. Thereby, in the downstream heat exchange part 207, the further raise of air is suppressed. And it is suppressed that air flows into the freezer compartment 102 from the blower outlet 112.

  Further, in the upstream heat exchange unit 206, the liquid refrigerant does not evaporate and flows out from the outlet 263 to the outside of the upstream heat exchange unit 206 as a liquid refrigerant. As described above, since the second on-off valve 210 is closed, the refrigerant flows into the second expander 204 from the branch b21. The second expander 204 uses a capillary tube. The liquid refrigerant is decompressed as it is expanded in the second expander 204. At this time, the liquid refrigerant becomes a decompressed liquid refrigerant and flows into the downstream heat exchange unit 207 from the inlet 272. The decompressed refrigerant flows into the downstream heat exchange unit 207 and is evaporated (that is, vaporized) by heat exchange to become a gaseous refrigerant. Then, the gaseous refrigerant evaporated in the downstream heat exchange unit 207 returns from the outlet 273 to the compressor 201 through the piping.

  A downstream heat exchange unit 207 is disposed above the upstream heat exchange unit 206. Even during the defrosting operation, the refrigerant evaporates (that is, vaporizes) in the downstream heat exchange section 207. The refrigeration capacity of the downstream heat exchange unit 207 is lower than the refrigeration capacity of the upstream heat exchange unit 206.

  In addition, high-temperature air heated by the upstream heat exchange unit 206 flows into the downstream heat exchange unit 207. In the downstream heat exchange unit 207, heat exchange between the evaporated refrigerant and the inflowing high-temperature air (that is, cooling of the inflowing air) is performed. The temperature of the air cooled by the downstream heat exchange unit 207 is higher than the freezing point of water. That is, the temperature of the cooled air does not become lower than the freezing point of water by the amount of expansion of the second expander 204 and the refrigeration capacity of the downstream heat exchange unit 207. Thereby, even if a refrigerant | coolant evaporates inside the downstream heat exchange part 207 at the time of a defrost operation, the frost formation in the downstream heat exchange part 207 is suppressed.

  And in the downstream heat exchange part 207, the high temperature air from the upstream heat exchange part 206 is cooled, and the temperature of air falls. At this time, since the fan 110 is stopped, air convection is generated inside the first duct 107. Thereby, even when performing the defrosting operation, it is possible to suppress the heated air generated in the defrosting operation from flowing into the freezer compartment 102. From this, it is possible to suppress deterioration of stored items due to a decrease in cooling efficiency of the refrigerator Rf and a temperature increase in the freezer compartment 102, the refrigerator compartment 103, and the like.

  That is, in the cooling device 2, during the defrosting operation, the refrigerant is decompressed by the second expander 204, and the refrigerant decompressed by the downstream heat exchange unit 207 is evaporated. At this time, the throttle amount of the second expander 204 is smaller than the throttle amount of the first expander 203, and the refrigeration capacity of the downstream heat exchange unit 207 is smaller than the refrigeration capacity of the upstream heat exchange unit 206. Thereby, the temperature of the cool air generated in the downstream heat exchanger 207 is a temperature at which the downstream heat exchanger 207 is not frosted. In addition, the air heated in the upstream heat exchange unit 206 is cooled by the cold air generated in the downstream heat exchange unit 207.

  The refrigerator Rf includes a control circuit (not shown). The control circuit controls the start and stop timings of the cooling operation of the cooling device 2, the start and stop timings of the defrosting operation, and the like. Note that the start and stop timing of the cooling operation is performed based on, for example, the internal temperature detected by the temperature sensors provided in the freezer compartment 102 and the refrigerator compartment 103. In addition, the start and stop timings of the defrosting operation are controlled based on, for example, the time from the end of the previous defrosting operation, the outside air temperature, the number of times the door is opened and closed, and the like. The control circuit switches between the cooling operation (first flow path Cp1) and the defrosting operation (second flow path Cp2) by controlling the opening and closing of the first on-off valve 209 and the second on-off valve 210.

  By using the cooling device 2 configured as described above, it is possible to perform a defrosting operation without using a heater. In addition, the liquid refrigerant can be prevented from flowing into the compressor 201, and the compressor 201 can be prevented from being broken or damaged.

<Modification 1>
A modification of the second heat exchanger will be described with reference to the drawings. FIG. 6 is a perspective view of another example of the second heat exchanger used in the cooling device provided in the refrigerator according to the present invention. 6, the configurations of the upstream heat exchange unit 206 and the downstream heat exchange unit 207 are the same as the configurations of the upstream heat exchange unit 206 and the downstream heat exchange unit 207 shown in FIG. Are denoted by the same reference numerals, and detailed description of the same parts is omitted. In the following description, the horizontal direction may be described as the H direction and the vertical direction as the V direction.

  As shown in FIG. 6, in the second heat exchanger 205b, the upstream heat exchange unit 206 and the downstream heat exchange unit 207 are arranged in the horizontal direction (H direction). In such a case, it is difficult to cause the air heated by the upstream heat exchange unit 206 to flow into the downstream heat exchange unit 207 only by air convection. Therefore, by disposing the fan 110, it is possible to cause an air flow to flow from the upstream heat exchange unit 206 to the downstream heat exchange unit 207 in the horizontal direction (H direction).

  In the second heat exchanger 205b, a connecting member 264 that connects the fin 261 of the upstream heat exchange unit 206 and the fin 271 of the downstream heat exchange unit 207 is provided. That is, the second heat exchanger 205b has a plurality of fins 261 and 271 fixed to the refrigerant pipe, and connects the fin 261 of the upstream heat exchange unit 206 and the fin 271 of the downstream heat exchange unit 207. A member 264 is provided.

  The connecting member 264 is a plate-like member formed of a member having high thermal conductivity (for example, the same material as the fins 261 and 271). The connecting member 264 can transfer the heat of the fins 261 heated by the upstream heat exchange unit 206 during the defrosting operation to the fins 271 of the downstream heat exchange unit 207.

  The air heated by the upstream heat exchanging unit 206 flows to the downstream heat exchanging unit 207 by the airflow generated by driving the fan 110. That is, the second heat exchanger 205 b includes the fan 110 that blows air to the upstream heat exchange unit 206 and the downstream heat exchange unit 207, and the downstream heat exchange unit 207 is connected to the upstream heat exchange unit 206. And disposed downstream of the air flow generated by the fan 110.

  Further, the connecting member 264 connects the fin 261 and the fin 271, whereby the heat of the fin 261 can be transmitted to the fin 271. Thereby, the downstream heat exchange part 207 can be heated at the time of defrosting, and when performing the defrosting of the upstream heat exchange part 206, it is possible to defrost the downstream heat exchange part 207 efficiently. .

  Note that the rotation of the fan 110 may be controlled so that the flow rate of the airflow may be less during the defrosting operation than during the cooling operation. Thereby, it can control that hot air flows into freezer compartment 102 at the time of defrosting operation. Moreover, although the connection member 264 connects the planes of the fins 261 and 271, the present invention is not limited to this. The connecting member 264 may be a member that connects the upper surface or the lower surface, for example. Further, all of the fins 261 and 271 may be connected by a connecting member, or one or several sets of fins 261 and fins 271 may be connected by a connecting member.

<Modification 2>
Another modification of the second heat exchanger will be described with reference to the drawings. FIG. 7 is a perspective view showing still another example of the second heat exchanger used in the cooling device provided in the refrigerator according to the present invention. In the second heat exchanger 205c illustrated in FIG. 7, the upstream heat exchange unit 206 and the downstream heat exchange unit 207 are arranged in the horizontal direction (H direction), and the fins 261 and 271 are in contact with each other. That is, the second heat exchanger 205c has a plurality of fins 261 and 271 fixed to the refrigerant pipe, and the fin 261 of the upstream heat exchange unit 206 and the fin 271 of the downstream heat exchange unit 207 are in contact with each other. doing. By arrange | positioning in this way, the heat of the fin 261 of the upstream heat exchange part 206 at the time of a defrost operation can be efficiently transmitted to the fin 271 of the downstream heat exchange part 207 efficiently.

  Thus, since it is the structure which the fin 261 and the fin 271 contact, even if it does not drive the fan 110 at the time of a defrost operation, the defrost of the downstream heat exchange part 207 can be performed efficiently. Note that, similarly to the second heat exchanger 205b, the fan 110 may be rotated during defrosting.

  The upstream heat exchange unit 206 and the downstream heat exchange unit 207 may be arranged in the vertical direction (V direction), and the fins may contact each other. Also at this time, the upstream heat exchange unit 206 is disposed below the downstream heat exchange unit 207.

<Modification 3>
Still another modification of the second heat exchanger will be described with reference to the drawings. FIG. 8: is a perspective view which shows the further another example in the 2nd heat exchanger used for the cooling device with which the refrigerator concerning this invention is equipped. As for the 2nd heat exchanger 220 shown in FIG. 8, the upstream heat exchange part 221 and the downstream heat exchange part 222 are arranged up and down. The second heat exchanger 220 includes a common fin 223. That is, the second heat exchanger 220 has a plurality of fins fixed to the refrigerant pipe, and the upstream heat exchange unit 221 and the downstream heat exchange unit 222 have a common fin 223.

  In the upstream heat exchange unit 221, a refrigerant pipe is fixed to the lower part of the plurality of arranged fins 223. The upstream heat exchange unit 221 includes an inflow port 224 and an outflow port 225. The downstream heat exchange unit 222 has a refrigerant pipe fixed to the upper part of the plurality of fins 223 arranged. The downstream heat exchange unit 222 includes an inflow port 226 and an outflow port 227. In addition, the 2nd heat exchanger 220 has a fan attached to the upper part similarly to the 2nd heat exchanger 205 shown in FIG.

  By using the common fin 223 for the upstream heat exchange unit 221 and the downstream heat exchange unit 222, the heat of the upstream heat exchange unit 221 can be quickly transferred to the downstream heat exchange unit 222 during the defrosting operation. Is possible. Thereby, it is possible to quickly defrost the downstream heat exchange unit 222.

  By adopting such a configuration, the defrosting operation of the second heat exchanger 220 can be performed in a short time, so that high-temperature air is prevented from flowing into the freezer compartment 102, the refrigerator compartment 103, or the like. Is possible. Moreover, the 2nd heat exchanger 220 can be integrated by using the fin 223 common to the upstream heat exchange part 221 and the downstream heat exchange part 222. FIG. Furthermore, it is possible to save troubles such as transportation and assembly during manufacturing of the cooling device. Further, the outer shape of the second heat exchanger 220 can be reduced in size as compared with the configuration in which the upstream heat exchange unit and the downstream heat exchange unit are separated.

  In the second heat exchanger 220, all the fins are common fins 223, but the present invention is not limited to this. If a common fin 223 is used for a part (or at least one), the remaining fins may be independent fins in the upstream heat exchange unit 221 and the downstream heat exchange unit 222 (for example, in FIG. The fins 261 and 271 of the second heat exchanger shown may be used. By using many fins as the common fin 223, the heat transfer effect can be enhanced and the strength of the second heat exchanger 220 can be increased.

<Modification 4>
Still another modification of the second heat exchanger will be described with reference to the drawings. FIG. 9 is a perspective view showing still another example of the second heat exchanger used in the cooling device provided in the refrigerator according to the present invention. In the second heat exchanger 230 shown in FIG. 9, the upstream heat exchange unit 231 and the downstream heat exchange unit 232 are arranged in the horizontal direction (H direction). The second heat exchanger 233 includes a common fin 233.

  In the upstream heat exchanger 231, a refrigerant pipe is fixed to the upstream side in the air flow direction of the plurality of arranged fins 233. The upstream heat exchange unit 231 includes an inflow port 234 and an outflow port 235. In the downstream heat exchange section 232, a refrigerant pipe is fixed to the downstream side in the airflow direction of the plurality of arranged fins 233. The downstream heat exchange unit 232 includes an inflow port 236 and an outflow port 237. Note that the fan 110 is attached to the side of the second heat exchanger 230 in the same manner as the second heat exchanger 205c shown in FIG.

  By using the common fin 233 for the upstream heat exchange unit 231 and the downstream heat exchange unit 232, the heat of the upstream heat exchange unit 231 can be quickly transferred to the downstream heat exchange unit 232 during the defrosting operation. Is possible. Thereby, it is possible to defrost the downstream heat exchange part 232 quickly.

  By adopting such a configuration, it is possible to perform the defrosting operation of the second heat exchanger 230 in a short time, so that high temperature air is prevented from flowing into the freezer compartment 102 or the refrigerator compartment 103. Is possible. In addition, since the fins 233 common to the upstream heat exchange unit 231 and the downstream heat exchange unit 232 are used, the second heat exchanger 230 can be integrated, and transportation and assembly during manufacturing of the cooling device can be performed. Can be saved.

  In the second heat exchanger 230, all fins are common fins 233, but the present invention is not limited to this. If a common fin 233 is used for a part (or at least one), the remaining fins may be independent fins in the upstream heat exchange unit 231 and the downstream heat exchange unit 232 (for example, FIG. The fins 261 and 271 of the second heat exchanger 205c may be used. By using many fins as the common fin 233, the heat transfer effect can be enhanced, and the strength of the second heat exchanger 230 can be enhanced.

  As described above, the configuration of the second heat exchanger has been described with a plurality of types (four types), but the present invention is not limited to these. If the 2nd heat exchanger concerning the present invention is the composition by which the downstream heat exchange part is provided in the downstream of the flow direction of the high temperature air (namely, warm air) which occurred in the upstream heat exchange part, It is not particularly limited. In addition to the above-described configuration, the second heat exchanger according to the present invention has a configuration in which the heat of the upstream heat exchange unit is quickly transferred to the downstream heat exchange unit during defrosting (for example, the connecting member described above) Or a common fin). In the following description of other embodiments of the cooling device, the description will be made assuming that the second heat exchanger 205 shown in FIG. 3 is used. Two coolers may be used.

(Second Embodiment)
Another example of the refrigerator according to the present invention will be described with reference to the drawings. FIG. 10 is a piping diagram during cooling operation of another example of the cooling device provided in the refrigerator according to the present invention. FIG. 11 is a piping diagram during the defrosting operation of the cooling device shown in FIG. 10. In addition, in the refrigerator of this embodiment, it replaces with the cooling device 2 and the cooling device 2B is used. The configuration of the cooling device 2B is the same as the configuration of the cooling device 2 except that the switching unit 211 is different from the switching unit 208. Parts other than the cooling device have the same configuration, and a detailed description thereof will be omitted. Also, in the description of the cooling device 2B, parts other than the switching unit 211 are denoted by the same reference numerals, and detailed description of the same parts as described above is omitted.

  As shown in FIG. 10, in the cooling device 2B, a first bypass pipe 212 that connects the branch b11 and the branch b12 of the pipe is provided, and a second bypass pipe 214 that connects the branch b21 and the branch b22 is provided. Yes. That is, the refrigerator according to the present invention includes a first bypass passage 212 that bypasses the first expander 203 and a second bypass passage 214 that bypasses the second expander 204. The switching unit 211 includes a first switching valve 213 provided in the branch b11 and a second switching valve 215 provided in the branch b21.

  The first switching valve 213 is a switching valve that switches the flow direction of the refrigerant from the first heat exchanger 202 to either the first expander 203 or the first bypass pipe 212. The second switching valve 215 is a switching valve that switches the direction in which the refrigerant from the upstream heat exchange unit 206 flows to either the second expander 204 or the second bypass pipe 214. In FIG. 10 or FIG. 11, it is shown that the refrigerant does not flow through the pipe to which the black triangle is connected.

  That is, in the refrigerator according to the present invention, the switching unit 211 includes the first switching valve 214 that causes the refrigerant from the first heat exchanger 202 to flow to either the first expander 203 or the first bypass flow channel 212, and the upstream. And a second switching valve 215 that causes the refrigerant from the side heat exchange unit 206 to flow to either the second expander 204 or the second bypass flow path 214.

  In the cooling device 2 </ b> B, when the first switching valve 213 is switched, the refrigerant from the first heat exchanger 202 can flow to the first expander 203. Further, when the second switching valve 215 is switched, the refrigerant from the upstream heat exchange unit 206 can be caused to flow into the downstream heat exchange unit 207 via the second bypass pipe 214. As described above, by switching between the first switching valve 213 and the second switching valve 215, the cooling device 2B substantially has the compressor 201, the first heat exchanger 202, the first expander 203, and the upstream heat. A first flow path Cp11 is configured in which the exchange unit 206 and the downstream heat exchange unit 207 are sequentially connected in series by piping.

  That is, in the refrigerator according to the present invention, when the first flow path Cp11 is configured, the first switching valve 213 causes the refrigerant from the first heat exchanger 202 to flow to the first expander 203 and the second switching. The valve 215 allows the refrigerant from the upstream heat exchange unit 206 to flow into the second bypass flow path 214.

  In the cooling device 2B, when the first flow path Cp11 is configured, the second heat exchanger 205 including the upstream heat exchange unit 206 and the downstream heat exchange unit 207 evaporates by driving the compressor 201. Serves as a cooler, that is, a cooler. In the cooling device 2B, a cooling operation is performed.

  In the cooling device 2 </ b> B, when the first switching valve 213 is switched, the refrigerant from the first heat exchanger 202 can flow to the upstream heat exchange unit 206 via the first bypass pipe 212. Further, when the second switching valve 215 is switched, the refrigerant from the upstream heat exchange unit 206 can flow into the second expander 204. As described above, by switching between the first switching valve 213 and the second switching valve 215, in the cooling device 2B, the compressor 201, the first heat exchanger 202, the upstream heat exchange unit 206, the second A second flow path Cp21 is configured in which the expander 204 and the downstream heat exchange unit 207 are sequentially connected in series by piping.

  That is, in the refrigerator according to the present invention, when the second flow path Cp21 is configured, the first switching valve 213 causes the refrigerant from the first heat exchanger 202 to flow into the first bypass flow path 212 and the second flow path Cp21. The switching valve 215 allows the refrigerant from the upstream heat exchange unit 206 to flow to the second expander 204.

  When the second flow path Cp21 is configured in the cooling device 2B, by driving the compressor 201, the high-pressure liquid refrigerant flowing out from the first heat exchanger 202 flows into the upstream heat exchange unit 206. . The flowing high-pressure liquid refrigerant exchanges heat with frost in the upstream heat exchange unit 206. In addition, the refrigerant flowing out of the upstream heat exchange unit 206 is decompressed by the second expander 204 and flows into the downstream heat exchange unit 207, whereby the refrigerant evaporates in the downstream heat exchange unit 207 and becomes a gaseous refrigerant. Return to compressor. Thereby, the cooling device 2B performs a defrosting operation in which the attached frost is melted and removed.

  By using a valve (such as the first switching valve 213 and the second switching valve 215) that can switch the flow path as in the cooling device 2B, when the refrigerant flows to the bypass side, a part of the refrigerant is first. The flow into the expander 203 or the second expander 204 can be suppressed. Thereby, in a cooling device, cooling or defrosting can be performed efficiently. Thereby, the power consumption of the refrigerator Rf can be reduced.

  Features other than the structure of the cooling device 2B are the same as those in the first embodiment.

(Third embodiment)
Still another example of the refrigerator according to the present invention will be described with reference to the drawings. FIG. 12 is a piping diagram during the cooling operation of still another example of the cooling device provided in the refrigerator according to the present invention. FIG. 13 is a piping diagram during the defrosting operation of the cooling device shown in FIG. 12. In addition, in the refrigerator of this embodiment, it replaces with the cooling device 2 and 2C of cooling devices are used. The cooling device 2C includes a switching unit 216 different from the switching unit 208, and the first expander 217 also serves as the second expander. Parts other than the cooling device have the same configuration, and a detailed description thereof will be omitted. Also, in the description of the cooling device 2C, substantially the same portions are denoted by the same reference numerals, and detailed descriptions of the same portions as those described above are omitted.

  As shown in FIG. 12, in the cooling device 2C, a four-way valve (direction control valve) is used as the switching unit 216. The cooling device 2C includes a first expander 217 that also serves as a second expander. The first expander 217 and the upstream heat exchange unit 206 (that is, the inlet 262 of the upstream heat exchange unit 206) are connected in series. Further, the downstream heat exchange unit 207 (that is, the outlet 273 of the downstream heat exchange unit 207) is connected in series with the compressor 201.

  In the refrigerator according to the present embodiment, the first expander 217 also serves as the second expander, and the first expander 217 and the upstream heat exchange unit are connected in series. The switching unit 216 has a direction control valve (four-way valve).

  The switching unit 216 includes four connection ports. In the following description, for convenience, the four connection ports will be described with numbers 1-4. A pipe from the first heat exchanger 202 is connected to the first connection port of the switching unit 216. In addition, a pipe located on the opposite side of the pipe connected to the upstream heat exchange unit 206 of the first expander 217 is connected to the second connection port. A pipe located on the opposite side to the pipe connected to the first expander 217 of the upstream heat exchange unit 206 (that is, connected to the outlet 263) is connected to the third connection port. Further, a pipe located on the opposite side to the pipe connected to the compressor 201 of the downstream heat exchange section 207 (that is, connected to the inlet 272) is connected to the fourth connection port.

  In the refrigerator according to the present embodiment, the direction control valve of the switching unit 216 includes a first heat exchanger 202, a first expander 217, an upstream heat exchange unit 206, and a downstream heat exchange unit 207. It is connected.

  The switching unit 216 connects the first and second connection ports and connects the third and fourth connection ports (the state shown in FIG. 12) and the first and fourth connections. The connection state is switched to the second connection state (state shown in FIG. 13) in which the second and third connection ports are connected.

  As shown in FIG. 12, when the switching unit 216 is in the first connection state, the cooling device 2C substantially has the compressor 201, the first heat exchanger 202, the first expander 217, and the upstream heat exchange unit 206. And the downstream heat exchange part 207 is connected in series with piping in order, and the 1st flow path Cp12 is comprised. That is, in the refrigerator according to the present invention, when the first flow path Cp12 is configured, the directional control valve allows the first heat exchanger 202 and the first expander 217 to communicate with each other and the upstream heat exchange unit 206. And the downstream heat exchange section 207 are communicated with each other.

  In the cooling device 2C, when the first flow path Cp12 is configured, the second heat exchanger 205 including the upstream heat exchange unit 206 and the downstream heat exchange unit 207 is evaporated by driving the compressor 201. Serves as a cooler, that is, a cooler. In the cooling device 2C, a cooling operation is performed.

  As shown in FIG. 13, when the switching unit 216 is in the second connection state, the cooling device 2C substantially has the compressor 201, the first heat exchanger 202, the upstream heat exchange unit 206, and the first expander 217. And the downstream heat exchange part 207 is connected in series by piping in order, and the 2nd flow path Cp22 is comprised. That is, in the refrigerator according to the present invention, when the second flow path Cp22 is configured, the direction control valve allows the first heat exchanger 202 and the upstream heat exchange unit 206 to communicate with each other and the first expander 217. And the downstream heat exchange section 207 are communicated with each other.

  In the cooling device 2C, when the second flow path Cp22 is configured, by driving the compressor 201, the high-pressure liquid refrigerant flowing out from the first heat exchanger 202 flows into the upstream heat exchange unit 206. To do. The high-pressure liquid refrigerant exchanges heat with frost in the upstream heat exchange unit 206. In addition, the refrigerant flowing out from the upstream heat exchange unit 206 is decompressed by the first expander 217 and flows into the downstream heat exchange unit 207. Thereby, the decompressed refrigerant evaporates in the downstream heat exchange section 207 and returns to the compressor as a gaseous refrigerant. As a result, the cooling device 2C can perform a defrosting operation by melting and removing the attached frost.

  As described above, by using a four-way valve (direction control valve) as the switching unit 216, the configuration of the switching unit can be simplified. Further, since the second expander can be omitted and the expander can be one of the first expanders 217, the piping can be simplified and the configuration of the cooling device 2C can be simplified. Moreover, it is possible to increase the degree of freedom of the layout of the cooling device 2C.

  The configuration of the cooling device 2C is the same as that of the first embodiment and the second embodiment except for the configuration described above, and the description thereof is omitted.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to this content. The embodiments of the present invention can be variously modified without departing from the spirit of the invention.

  The refrigerator of this invention can be utilized as a refrigerator which can suppress the fall of the cooling efficiency inside a storage (refrigeration room and freezer compartment).

Rf ... refrigerator, 1 ... outer box, 101 ... partition shelf, 102 ... freezer compartment, 103 ... refrigerator compartment, 104 ... door, 105 ... door, 106 ... Partition wall 107 ... first duct 108 ... second duct 109 ... first damper 110 ... fan 111 ... second damper 112 ... outlet 113 ... Return port, 114 ... Communication duct, 115 ... Return port, 116 ... Machine room, 2, 2B, 2C ... Cooling device, 201 ... Compressor, 202 ... No. 1 heat exchanger (condenser), 203 ... 1st expander, 204 ... 2nd expander, 205, 205b, 205c ... 2nd heat exchanger, 206 ... upstream heat exchanger 260, refrigerant pipe, 261, fin, 262, inlet, 263, outlet, 264, connection part 207 ... downstream heat exchanger, 271 ... fin, 272 ... inflow port, 273 ... outflow port, 208 ... switching unit, 209 ... first on-off valve, 210 .. second on-off valve, 211... Switching unit, 212... First bypass piping, 213... First switching valve, 214... Second bypass piping, 215. b11 ... branch, b12 ... branch, b21 ... branch, b22 ... branch, 216 ... switch, 217 ... first expander, 220 ... second heat exchanger, 221 ... Upstream heat exchange section, 222 ... Downstream heat exchange section, 223 ... Fins, 224 ... Inlet, 225 ... Outlet, 226 ... Inlet, 227 ... -Outlet, 230 ... 2nd heat exchanger, 231 ... Upstream heat exchange part, 232 ... Downstream heat exchange part 233 ... Fin, 234 ... Inlet, 235 ... Outlet, 236 ... Inlet, 237 ... Outlet, Cp1, Cp11, Cp12 ... First flow path, Cp2, Cp21 , Cp22 ... second flow path

Claims (11)

A compressor,
A first heat exchanger;
A second heat exchanger including an upstream heat exchange section and a downstream heat exchange section;
A first expander connected to the first heat exchanger and the upstream heat exchange unit;
A second expander connected to the upstream heat exchange section and the downstream heat exchange section;
A cooler that cools the storage chamber with the second heat exchanger,
A first flow path is constituted by the compressor, the first heat exchanger, the first expander, the upstream heat exchange unit, and the downstream heat exchange unit,
A second flow path is constituted by the compressor, the first heat exchanger, the upstream heat exchange unit, the second expander, and the downstream heat exchange unit,
A refrigerator in which the switching unit switches between the first flow path and the second flow path.   The refrigerator according to claim 1, wherein the first flow path is configured during cooling, and the second flow path is configured during defrosting. The switching unit is disposed in parallel with the first expander, and is disposed in parallel with the first on-off valve having a flow path resistance lower than that of the first expander and the second expander when in the open state. A second on-off valve having a flow path resistance lower than that of the second expander in the open state;
When the first flow path is configured, the first on-off valve is closed and the second on-off valve is opened,
The refrigerator according to claim 1 or 2, wherein when the second flow path is configured, the first on-off valve is opened and the second on-off valve is closed. A first bypass channel that bypasses the first expander; and a second bypass channel that bypasses the second expander;
A first switching valve that causes the switching unit to flow the refrigerant from the first heat exchanger to either the first expander or the first bypass flow path; and the refrigerant from the upstream heat exchange unit to the first A second switching valve that flows to either one of the two expanders or the second bypass flow path,
When the first flow path is configured, the first switching valve causes the refrigerant from the first heat exchanger to flow to the first expander, and the second switching valve is a refrigerant from the upstream heat exchange unit. To the second bypass flow path,
When the second flow path is configured, the first switching valve causes the refrigerant from the first heat exchanger to flow into the first bypass flow path, and the second switching valve from the upstream heat exchange section. The refrigerator according to claim 1 or 2, wherein a refrigerant is allowed to flow through the second expander.   The refrigerator according to claim 3 or 4, wherein a throttle amount of the second expander is smaller than a throttle amount of the first expander. The first expander also serves as the second expander, and the first expander and the upstream heat exchange unit are connected in series,
The switching unit has a directional control valve,
The directional control valve is connected to the first heat exchanger, the first expander, the upstream heat exchange unit, and the downstream heat exchange unit,
When the first flow path is configured, the directional control valve allows the first heat exchanger and the first expander to communicate with each other, and allows the upstream heat exchange unit and the downstream heat exchange unit to communicate with each other. ,
When the second flow path is configured, the directional control valve communicates the first heat exchanger and the upstream heat exchange unit, and communicates the first expander and the downstream heat exchange unit. The refrigerator according to claim 1 or claim 2.   The refrigerator according to any one of claims 1 to 6, wherein the downstream heat exchange section is disposed above the upstream heat exchange section. The second heat exchanger has a plurality of fins fixed to the refrigerant pipe,
The refrigerator according to any one of claims 1 to 7, wherein the fin of the upstream heat exchange section and the fin of the downstream heat exchange section are in contact with each other. The second heat exchanger has a plurality of fins fixed to the refrigerant pipe,
The refrigerator in any one of Claims 1-7 which provided the connection member which connects the fin of the said upstream heat exchange part, and the fin of the said downstream heat exchange part. The second heat exchanger has a plurality of fins fixed to the refrigerant pipe,
The refrigerator according to any one of claims 1 to 7, wherein the upstream heat exchange section and the downstream heat exchange section have a common fin. A fan for blowing air to the upstream heat exchange section and the downstream heat exchange section,
The said downstream heat exchange part is a refrigerator in any one of Claims 1-10 arrange | positioned with respect to the said upstream heat exchange part in the downstream of the airflow which generate | occur | produces with the said fan.

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