JP2006189209A - Cooling storage - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cooling storage capable of forming two kinds of freezing chambers of a very low temperature of minus 40°C or less, and an ordinary freezing temperature zone of about minus 18°C by utilizing cold produced by a sterling freezing machine without needing a special mechanism. <P>SOLUTION: This cooling storage 1 cools the inside of the storage by using the sterling freezing machine 50 as its cold source. A refrigerating compartment 20, a first freezing compartment 30L and a second freezing compartment 30R are formed inside of the storage. A heat absorbing portion 52 of the sterling freezing machine 50 is connected with a low temperature-side evaporator 72 through a secondary refrigerant circulating circuit 70, and the cold air produced by the cold of the low temperature-side evaporator 72 is directly supplied to the first freezing compartment 30L by a cooing fan device 83. The second freezing compartment 30R is cooled by the cold of the first freezing compartment 30L transmitted through a partitioning wall 32. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a refrigerator that cools the inside of the refrigerator with the cold generated in the heat absorption part of the Stirling refrigerator. “Refrigerator” is a concept that refers to all devices for lowering the temperature of food and other articles, and may be named as a product such as “refrigerator”, “freezer”, “freezer refrigerator”, and “showcase”.

  Specific chlorofluorocarbons (CFC: chlorofluorocarbon) and alternative chlorofluorocarbons (HCFC: hydrochlorofluorocarbon, HFC: hydrofluorocarbon) are used as refrigerants in the refrigeration cycle of the refrigerator. Among these refrigerants, CFCs and HCFCs are subject to international regulations for their production and use because they are, to some extent, lead to the destruction of the ozone layer. Another problem is that HFCs that do not destroy the ozone layer also have a significant contribution to global warming.

  Therefore, Stirling refrigerators that do not use ozone-depleting substances as a refrigerant are in the spotlight. The Stirling refrigerator uses an inert gas such as helium as the working medium, and the piston and displacer are operated by external power to repeatedly compress and expand the working medium to increase the temperature of the heat dissipating part (worm head) and the heat absorbing part ( Reduce the temperature of the cold head. Then, the heat radiating part radiates heat to the surrounding environment, and the heat absorbing part radiates heat from the interior.

  In recent years, a vacuum heat insulating material is often used as a heat insulating layer of a refrigerator. When a vacuum heat insulating material is used, since the heat intrusion is small, the internal temperature can be kept lower than before. When such a heat insulating material is combined with a Stirling refrigerator, a cryogenic temperature that has not been conceived in the past can be easily obtained even in a domestic refrigerator. This is also the reason why Stirling refrigerators attract attention.

Examples of the refrigerator that cools the inside with the cold generated by the Stirling refrigerator can be seen in Patent Documents 1 and 2. In Patent Document 2, the heat of the heat radiating part is transmitted to the opening of the cooling chamber through the refrigerant pipe to prevent condensation from occurring, and further, the heat is used to promote drain evaporation and remove the heat exchanger for cooling the inside of the cabinet. A configuration for use in frost is also shown. Patent Document 3 discloses a configuration of a refrigerator that discharges cold heat of cold air flowing through a cooling passage from a member that forms the cooling passage.
Japanese Patent Application Laid-Open No. 2002-221384 (pages 4-5, FIGS. 1-2) Japanese Patent Laying-Open No. 2004-20056 (pages 5 to 12, FIGS. 1 to 7) JP 2001-66040 A (pages 4 to 6, [0031], FIGS. 1 to 9)

  When a Stirling refrigerator is used, a freezing temperature of minus 40 ° C. or less can be obtained. When frozen and stored at such a low temperature for a long period of time, the quality of food can be kept much lower than when the refrigerator is stored frozen at minus 18 ° C. as a general refrigerator temperature. However, not all frozen foods need to be so cold. If frozen foods purchased at supermarkets and convenience stores can be stored for one or two days before being placed on the table, a general freezing room at minus 18 ° C is sufficient.

  The present invention has been made in view of the above points, and utilizes the cold generated by the Stirling refrigerator, and has two types of temperatures: an extremely low temperature of minus 40 ° C. or less and a normal freezing temperature zone of about minus 18 ° C. It is an object of the present invention to provide a refrigerator that can form a freezing chamber and that does not require any special device for its formation. It is another object of the present invention to provide a refrigerator that can solve the problem of frosting associated with a cryogenic freezer.

  In order to achieve the above object, the present invention provides a cooler that cools the inside of the refrigerator by cooling the heat absorbing portion of the Stirling refrigerator, and the refrigerator is adjacent to the upper compartment with a refrigerating chamber and a lower compartment separated by a partition wall. A freezer compartment and a second freezer compartment are provided, and the first freezer compartment is provided with a cooling fan device that directly blows cold air generated by the cold heat of the heat absorption part of the Stirling refrigerator, and the second freezer compartment has the above-mentioned The cooling heat of the first freezer compartment is transmitted through the partition wall.

  According to this structure, in the 1st freezer compartment, the cryogenic temperature of minus 40 degrees C or less can be easily obtained by directly blowing in cold air generated by the cold heat of the heat absorption part of the Stirling refrigerator. On the other hand, in the second freezer compartment, the cooling air is not blown in, but is cooled by the cold heat transmitted from the adjacent first freezer compartment via the partition wall. Since the temperature is extremely low, a normal freezing temperature of about minus 18 ° C. can be easily reached.

  According to the present invention, in the refrigerator having the above-described configuration, a duct having an inlet and an outlet that are open into the second freezer compartment is provided on the side of the partition wall facing the second freezer compartment. Is characterized in that a fan device for generating an air flow from the inlet to the outlet is provided.

  According to this configuration, by actively forming an airflow that flows along the wall surface of the partition wall, the cold heat of the first freezer compartment is transmitted to the airflow through the partition wall, and the second freezer compartment is It can be cooled quickly.

  Further, the present invention provides the cooler having the above-described configuration, wherein a cooler to which cold heat is supplied from the heat absorption part of the Stirling refrigerator is installed on the back side of the first freezer compartment, and the cooler, the refrigerator compartment, A cold air return duct connecting the two is installed on the back side of the second freezer compartment.

  According to this configuration, the thickness of the heat insulating material between the cold air return duct and the second freezer compartment can be reduced.

  Further, the present invention is characterized in that the refrigerator having the above-described configuration includes a secondary refrigerant circulation circuit that prevents the second freezer compartment from being overcooled by the heat generated by the Stirling refrigerator.

  According to this configuration, it is possible to mitigate overcooling of the second freezer compartment using the heat generated by the Stirling refrigerator.

  If a circulation pump is provided in the secondary refrigerant circulation circuit and this circulation pump is controlled based on a detection result of a temperature sensor provided in the second freezer compartment, the temperature of the second freezer compartment is accurately set to the target value. Can match.

  According to the present invention, in the cooler configured as described above, the fan rotation speed of the cooling fan device is maintained higher than usual for a predetermined time after the door opening / closing of the first freezer compartment.

  When moisture is brought into the first freezer compartment, the moisture immediately becomes frost and adheres to the inside of the first freezer compartment. According to the configuration of the present invention, when the door of the first freezer compartment is opened and moisture is brought in from the outside, the cooling fan device sends more wind than usual and enhances the sublimation capacity. It can return early.

  If the duct that feeds cold air to the refrigerator compartment is closed by a damper while the number of rotations of the cooling fan device is kept high, the duct goes to the refrigerator compartment when the sublimation capacity in the first freezer compartment needs to be increased. Since the cold air stops and the cold air concentrates in the first freezer compartment, the sublimation ability can be improved as intended.

  In addition, if it is assumed that the blower that sends cold air to the refrigerator compartment is stopped while the fan rotation speed of the cooling fan device is kept high, the refrigerator compartment is required when the sublimation capacity in the first freezer compartment needs to be increased. Since the distribution of the cold air stops and the cold air concentrates in the first freezer compartment, the sublimation capacity can be improved as intended.

  Further, if a defrost heater is built in the door of the first freezer compartment and the defrost heater is energized for a predetermined time after opening and closing the door of the first freezer compartment, frost adhering to the door of the first freezer compartment is removed. It can be removed reliably.

  In addition, if a temperature sensor for measuring the outside air temperature and a humidity sensor for measuring the outside humidity are provided and the length of the predetermined time is adjusted based on the measurement results of the temperature sensor and the humidity sensor, frost formation occurs. It is possible to perform a defrosting operation without waste by changing the control parameters in consideration of whether the environment is easy.

  According to the present invention, an extremely low temperature of minus 40 ° C. or less can be easily obtained by directly blowing cold air generated by the cold heat of the heat absorption part of the Stirling refrigerator into the first freezer. The second freezer compartment adjacent to the first freezer compartment is not blown with cold air, but is cooled by transmitting cold heat from the first freezer compartment via the partition wall. Since the chamber temperature is extremely low, it can be cooled to a normal freezing temperature of about minus 18 ° C. Therefore, even a refrigerator for home use can provide an extremely low temperature freezing room of minus 40 ° C. or less and a normal freezing room of around minus 18 ° C. at a low cost, and the user can use it for the kind of food or for storage purposes. The frozen storage can be performed accordingly.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 is a vertical sectional view of the refrigerator, FIG. 2 is a schematic front view of the refrigerator with the door removed, FIG. 3 is a horizontal sectional view of the refrigerator, FIG. 4 is a schematic configuration diagram of the cooling cycle, and FIG. FIG. 6 is a perspective view for explaining the piping path of the forced circulation circuit, and FIG. 7 is an operation timing chart.

  The refrigerator 1 is for food preservation, and the heat insulating housing 10 constitutes the main body. The inside of the heat insulating housing 10 is partitioned into two upper and lower stages by a horizontal partition wall 11, and the upper stage is set as a refrigerator compartment and a thawing room, and the lower stage is set as a freezer compartment. The freezer compartment is divided into right and left when viewed from the front by a vertical partition wall 32, and the left side is the first freezer compartment 30L and the right side is the second freezer compartment 30R. In the refrigerator compartment 20, the thawing compartment 25, and the freezer compartments 30L and 30R, the front (left side in FIG. 1) is an opening for taking in and out food, and the openings are provided with heat insulating doors 21, 31L and 31R. Close.

  A plurality of shelf boards 22 are provided inside the refrigerator compartment 20. Adjacent to the lowermost part of the refrigerator compartment 20 is a thawing chamber 25 having a heat insulating structure. The thawing chamber 25 shares a heat insulating door 21 with the refrigerator compartment 20 and also has a unique heat insulating door 26.

  The first freezer compartment 30L and the second freezer compartment 30R are also provided with means for separating and holding food. The means may be a shelf board or a pull-out type freezing container.

  A machine room 40 is formed on the back surface of the heat insulating housing 10. The machine room 40 is a rectangular parallelepiped structure configured by combining sheet metal parts, and the back side is open. A Stirling refrigerator 50 is installed in the machine room 40. The machine room 40 is placed at a height between the refrigerator compartment 20, the first freezer room 30L, and the second freezer room 30R.

  After the Stirling refrigerator 50 is installed, the back side opening of the machine room 40 is closed with a lid 44. The lid 44 is formed with a ventilation port 45 for taking in air for cooling the high-temperature side condenser described later and an opening 47 for connecting an outlet of an air-cooling duct described later.

  A part of the Stirling refrigerator 50 becomes a heat radiating portion 51, and a high temperature side evaporator 61 is attached thereto (see FIG. 2). The heat radiation part 51 and the high temperature side evaporator 61 are in a state of transferring heat between them, that is, in a state of being thermally connected. Two systems of secondary refrigerant circulation circuits are connected to the high temperature side evaporator 61.

  The first secondary refrigerant circulation circuit on the high temperature side is a thermosiphon circulation configured by connecting a high temperature side condenser 62 and a high temperature side evaporator 61 installed on the Stirling refrigerator 50 with a secondary refrigerant pipe. Circuit 60. The second secondary refrigerant circulation circuit on the high temperature side is a forced circulation circuit 110 including a secondary refrigerant pipe disposed in the outer wall of the heat insulating housing 10. The thermosiphon circulation circuit 60 and the forced circulation circuit 110 are in a parallel relationship. The thermosiphon circulation circuit 60 and the forced circulation circuit 110 are sealed with water (including an aqueous solution) or a hydrocarbon-based refrigerant.

  The high temperature side evaporator 61 has a shape in which the hollow ring is divided into two, and the inside of each half of the ring is an evaporation chamber 61a independent of each other (see FIG. 5). The reason for this shape is as follows. That is, if the high-temperature side evaporator 61 has a single ring shape, it is necessary to strictly manage the shape and ensure the fitting accuracy in order to firmly contact the heat radiation part 51 of the Stirling refrigerator 50. If the high temperature side evaporator 61 is made into the shape which halved the hollow ring like this point this embodiment, the clamping pressure at the time of clamp | tightening the heat sink 51 of the Stirling refrigerator 50 between the half rings will be sufficient. Since the contact pressure can be controlled by adjusting the contact pressure, the contact pressure becomes insufficient due to the shape error, and the heat transfer rate with the heat radiating portion 51 is unlikely to fall. The same is true if the ring is divided into more blocks.

  The high-temperature side condenser 62 has a structure in which a pipe made of a metal having good heat conductivity such as copper, copper alloy, and aluminum is bent, and a plurality of heat radiation fins 63 made of a metal having good heat conductivity are attached thereto.

  As shown in FIG. 5, the outgoing side secondary refrigerant pipe 64 of the thermosiphon circulation circuit 60 is led out from the two evaporation chambers 61 a of the high temperature side evaporator 61. The two forward-side secondary refrigerant pipes 64 merge outside the high-temperature side evaporator 61 and are connected to the high-temperature side condenser 62 as one pipe. The return side secondary refrigerant pipe 65 returns from the high temperature side condenser 62, and the return side secondary refrigerant pipe 65 also branches before the high temperature side evaporator 61 to form two pipes. One by one is connected to the evaporation chamber 61a.

  Similarly, the forced circulation circuit 110 joins after being led out from the two evaporation chambers 61a, and when it returns, it branches before the high-temperature side evaporator 61 to form two pipes. Each is connected to the evaporation chamber 61a. The configuration of the forced circulation circuit 110 will be described in detail later.

  The Stirling refrigerator 50 is provided with a heat absorption part 52 that transmits cold heat to the outside in a pair with the heat radiation part 51. The low temperature side condenser 71 is attached to this heat absorption part 52 (refer FIG. 4). The heat absorption part 52 and the low temperature side condenser 71 are in a state of transferring heat between them, that is, in a state of being thermally connected.

A low-temperature evaporator 72 serving as a cooler that cools the interior of the refrigerator is disposed in the back of the first freezer compartment 30L and the second freezer compartment 30R. The low temperature side condenser 71 and the low temperature side evaporator 72 are connected by a secondary refrigerant pipe, and constitute a low temperature side secondary refrigerant circulation circuit 70. The secondary refrigerant circulation circuit 70 is filled with a natural refrigerant such as CO ₂ . The low temperature side condenser 71 is a single hollow ring shape, and the inside becomes the condensation chamber 71a (refer FIG. 5). 2 and 3, the low-temperature side evaporator 72 is biased toward the first freezer compartment 30L, and most of the low-temperature evaporator 72 overlaps the first freezer compartment 30L when viewed from the front. Only a little overlap.

  Similarly to the high temperature side condenser 62, the low temperature side evaporator 72 bends a pipe made of a metal having good heat conductivity such as copper, a copper alloy, and aluminum, and a plurality of heat radiation fins 73 also made of a metal having high heat conductivity. It is an attached structure.

  Cooling ducts 80 and 81 extending in the vertical direction along the inner wall on the back side are provided inside the heat insulating housing 10. The cooling duct 80 ends at a height halfway between the first freezer compartment 30L and the second freezer compartment 30R, and the cooling duct 81 extends to the ceiling of the refrigerator compartment 20 in a continuous manner.

  At the lower end of the cooling duct 80, an air inlet 82 for sucking the internal air from the freezer compartment 30 is provided. A low-temperature evaporator 72 is installed above the intake port 82, and a cooling fan device 83 for directly blowing cool air into the first freezer compartment 30L is provided above the intake port 82. The cooling duct 81 is provided with a cooling fan device that sends cold air from the cooling duct 80 and a damper (both not shown) that can arbitrarily block the flow of the cold air.

  The thawing room 25 is not only used for thawing frozen foods, but can also be switched to a refrigerated room or a freezer room. For this reason, the thawing chamber 25 communicates with the cooling duct 81 via a damper 86 (see FIG. 1). When used as a refrigeration chamber, the thawing chamber 25 takes in the amount of cold air necessary to obtain the refrigeration temperature from the cooling duct 81. When used as a freezing room, the cooling duct 81 takes in an amount of cold air necessary to obtain the freezing temperature.

  A cold air return duct 85 that collects air from the refrigerator compartment 20 and the thawing compartment 25 is also provided inside the heat insulating housing 10. The cold air return duct 85 connects the low-temperature side evaporator 72 and the refrigerator compartment 20, and is installed on the back side of the second freezer compartment 30R when viewed from the right side and the front side of the cooling duct 80. The air collected from the refrigerator compartment 20 and the thawing compartment 25 enters the cooling duct 80 from the cold return duct 85 and is supplied to the lower side of the low temperature evaporator 72. The cold air return duct 85 extends in close contact with the inner wall of the second freezer compartment 30R, and exchanges cold heat with the air in the second freezer compartment 30R.

  When the Stirling refrigerator 50 is operated, the heat dissipating part 51 becomes high temperature and the heat absorbing part 52 becomes low temperature. The heat of the heat radiating unit 51 is waste heat to be radiated to the outside, and this is absorbed by the secondary refrigerant of the thermosiphon circulation circuit 60 and then transmitted to the high temperature side condenser 62. The cold heat of the heat absorption part 52 is transmitted to the low temperature side evaporator 72 via the secondary refrigerant circulation circuit 70.

  When the cooling fan device 83 is operated here, the air in the first freezer compartment 30 </ b> L is sucked from the inlet 82 at the lower end of the cooling duct 80 and passes through the low temperature side evaporator 72. Further, air in the refrigerator compartment 20 and the thawing chamber 25 is sucked into the cooling duct 80 through the cold air return duct 85 and passes through the low temperature side evaporator 72. The air passing through the low temperature side evaporator 72 is cooled and becomes cold.

  The cold air is directly blown into the first freezer compartment 30L by the cooling fan device 83, and cools the first freezer compartment 30L. A part of the cool air is sent to the cooling duct 81 through the above-described cooling fan and damper (not shown), and further blown into the refrigerator compartment 20 through the outlet 84 provided in the cooling duct 81 to cool the refrigerator compartment 20. If the damper 86 is open, cold air is also sent to the thawing chamber 25. In this way, a predetermined amount of cold air is sent (or not sent) to the refrigerator compartment 20, the thawing compartment 25, and the freezer compartment 30, respectively, and the refrigerator compartment 20, the thawing compartment 25, and the freezer compartment 30 are each set to a predetermined temperature. To be cooled. The control unit 15 installed at the upper back of the heat insulating housing 10 governs the operation control.

  The high-temperature-side thermosiphon circulation circuit 60 is sufficiently circulated only by natural circulation, but the low-temperature-side secondary refrigerant circulation circuit 70 may not be able to obtain necessary circulation only by natural circulation. In such a case, a circulation pump is arranged in the secondary refrigerant circulation circuit 70 to perform forced circulation.

  In order to improve the operation efficiency of the Stirling refrigerator 50, it is necessary to efficiently release the condensation heat from the high temperature side condenser 62. For this purpose, an air cooling duct 90 is combined with the high temperature side condenser 62. The air cooling duct 90 is a synthetic resin molded product having a rectangular cross section of the ventilation path, and its inlet portion is applied to the upper surface of the high temperature side condenser 62 and its outlet portion is applied to the opening 47 of the lid 44. When viewed from the side, the air cooling duct 90 extends obliquely upward from the entrance to the exit at an angle of 45 ° with respect to the horizontal.

  A blower 91 for forcibly cooling the high temperature side condenser 62 is inserted into the air cooling duct 90. The blower 91 has two propeller fans arranged in the depth direction of FIG. 1, and the blowing direction coincides with the axis of the air cooling duct 90. The blower 91 can be taken in and out from the outlet of the air cooling duct 90, and is fixed to a mounting protrusion 93 that protrudes from the inner surface of the air cooling duct 90 in a form perpendicular to the duct axis with screws (not shown).

  When the blower 91 is operated, external air is sucked from the vent 45 of the lid 44. The air that has entered the machine room 40 passes through the high temperature side condenser 62 and takes away the heat of condensation released by the high temperature side condenser 62. The air deprived of heat is sucked into the air-cooling duct 90, further sucked into the blower 91, and discharged from there to the outside obliquely upward.

  The lid 44 of the machine room 40 is not a simple flat plate, but has a shape in which the center protrudes toward the back side and the four circumferences are inclined. Out of these slope portions, the outlet of the air cooling duct 90 opens to the slope portion facing obliquely upward. For this reason, a gap of a certain level or more is generated between the outlet of the air cooling duct 90 and the wall surface of the room in which the refrigerator 1 is installed, so that air flows smoothly. In order to air-cool the high temperature side condenser 62, a large amount of air is required, but the Stirling refrigerator 50 can always be operated efficiently by securing the air discharge path in this way.

  The waste heat radiated from the heat radiating unit 51 is also used to prevent dew condensation at the openings of the refrigerator compartment 20, the first freezer compartment 30L, and the second freezer compartment 30R. This is realized by the forced circulation circuit 110 disposed in the outer wall of the heat insulating housing 10. Both ends of the forced circulation circuit 110 serve as an inlet portion 110 a and an outlet portion 110 b connected to the high temperature side evaporator 61. Each of the inlet portion 110a and the outlet portion 110b is configured by two pipes led out from the two evaporation chambers 61a of the high temperature side evaporator 61 one by one. In the illustrated embodiment, the return-side secondary refrigerant pipe 65 is also used as the outlet 110b.

  The two pipes constituting the inlet portion 110a merge soon after leaving the evaporation chamber 61a to form one forced circulation circuit 110. The single forced circulation circuit 110 is connected to a circulation pump 111 (see FIG. 6) disposed near the bottom of the heat insulating housing 10. The circulation pump 111 is for forcibly circulating the secondary refrigerant in the forced circulation circuit 110.

  The forced circulation pipe 110 exiting the pump 111 passes through the lower edge of the opening of the first freezer compartment 30L and the second freezer compartment 30R, and then reaches the branch point 112 at the back of the heat insulating housing 10. After the branch point 112, the forced circulation piping 110 is divided into two paths. That is, it is the 1st piping part 110c and the 2nd piping part 110d. The first piping portion 110c is lower than the Stirling refrigerator 50, specifically, the left and upper edges of the openings of the first freezer compartment 30L and the second freezer compartment 30R, and the lower edge of the opening of the refrigerator compartment 20 Is the main piping area. 110 d of 2nd piping parts make the main piping area | region the part higher than the Stirling refrigerator 50, specifically, the right edge of the opening part of the refrigerator compartment 20, an upper edge, and a left edge.

  After leaving the branch point 112, the first piping part 110c proceeds to the left in the back side wall of the heat insulating housing 10. After reaching the left side wall, change direction and proceed to the front. When it reaches the opening of the first freezer compartment 30L, the direction is changed upward to the partition wall 11. When the partition wall 11 is reached, the direction is changed to the right, and the front edge of the partition wall 11 is advanced to the right. When it reaches the right end of the partition wall 11, it turns to the left and proceeds to the left on the route that has just come. When returning to the left end of the partition wall 11, change the direction and proceed upward. When it rises a little, the direction is changed to the back side, and the inside of the left side wall of the refrigerator compartment 20 is advanced in the back direction. Then, the machine room 40 is entered.

  After exiting the branch point 112, the second piping part 110d advances in the right side wall of the heat insulating housing 10 in the front direction. When it reaches the opening of the second freezer compartment 30R, the direction is changed upward, and the right edge of this opening is slightly raised. Then, the direction is changed to the back, and the auxiliary radiator 66 provided in the right side wall of the second freezer compartment 30R is connected. As with the high-temperature side condenser 62, the auxiliary radiator 66 bends a pipe made of a metal having good heat conductivity such as copper, copper alloy, and aluminum, and a plurality of heat radiation fins 63 made of a metal having good heat conduction are attached thereto. Structure. The second piping part 110d exiting the auxiliary radiator 66 returns to the right edge of the opening of the second freezer compartment 30R and rises to the ceiling wall of the refrigerator compartment 20. The direction is changed, and the upper edge of the opening of the refrigerator compartment 20 is moved to the left. When it reaches the left side wall of the refrigerator compartment 20, it changes direction and proceeds downward. When approaching the first piping part 110c, the direction is changed, and the inside of the left side wall of the refrigerator compartment 20 proceeds in the back direction. Then, the machine room 40 is entered.

  The first piping part 110c and the second piping part 110d join together after entering the machine room 40 to form one forced circulation piping 110. The forced circulation pipe 110 after the merge is branched again at the outlet 110b and becomes two pipes connected to the two evaporation chambers 61a. In this manner, the forced circulation circuit 110 is completed, starting from the high-temperature side evaporator 61 and making a round of the heating target portions of the refrigerator 1 and returning to the high-temperature side evaporator 61.

  The controller 15 drives the circulation pump 111 at all times or at a predetermined timing during the operation of the Stirling refrigerator 50. When the circulation pump 111 is driven, the secondary refrigerant that has absorbed the waste heat of the Stirling refrigerator 50 flows through the forced circulation circuit 110 and heats the outer wall of the casing in the piping region to prevent condensation.

  The forced circulation circuit 110 is held in a state in which the cushioning material 113 is interposed at an important point with respect to the inner surface of the outer wall of the refrigerator 1. The buffer material 113 surrounds the forced circulation circuit 110 as shown in FIG. 1, and the forced circulation circuit 110 is directly attached to the inner surface of the outer wall of the heat insulating housing 10 no matter how the forced circulation circuit 110 is displaced. There is no contact.

  In this way, even if the forced circulation circuit 110 vibrates, the vibration is not transmitted to the heat insulating housing 10 of the refrigerator 1, and vibration and noise are not amplified by the heat insulating housing 10. . Since the shock absorbing material 113 needs to achieve both vibration absorption and heat conduction, a material and a shape satisfying it are selected.

  If the operation of the refrigerator 1 is continued, moisture in the air in the refrigerator becomes frost and adheres to the low temperature side evaporator 72. Since frost lowers the heat exchange efficiency of the low temperature side evaporator 72, the control unit 15 energizes a defrost heater (not shown) at an appropriate timing to defrost the low temperature side evaporator 72. The defrosted water in which the frost has melted is received by the defrosted water receiver 120 at the bottom of the cooling duct 80, and is drained from the storage through the drain pipe 121.

  A defrost water storage container 130 for storing defrost water dripped from the drain pipe 121 is installed under the bottom wall of the heat insulating housing 10. The defrost water storage container 130 has a shallow dish shape, and the defrost water that has been drawn out from the front side of the refrigerator 1 and accumulated therein can be discarded.

  A part of the forced circulation circuit 110 is piped under the defrost water storage container 130. The defrost water accumulated in the defrost water storage container 130 is heated by the warm heat carried by the secondary refrigerant in the forced circulation circuit 110, and the temperature rises. For this reason, evaporation of defrost water is accelerated | stimulated and the effort which throws away defrost water can be reduced.

  Now, the air passing through the low temperature side evaporator 72 becomes cold air of minus 40 ° C. or less. The first freezing chamber 30L into which a large amount of this cold air is blown becomes an extremely low temperature of minus 40 ° C. or lower. The cryogenic cold in the first freezer compartment 30L is transmitted to the second freezer compartment 30R via the partition wall 32. By appropriately setting the heat transfer coefficient of the partition wall 32, the freezing temperature of the second freezer compartment 30R can easily reach the normal freezing temperature range of minus 18 ° C. without blowing cold air.

  In order to efficiently transmit cold heat to the air in the second freezer compartment 30R, a duct 33 is provided on the side of the partition wall 32 facing the second freezer compartment 30R. The duct 33 extends in the vertical direction along the partition wall 32, and an inlet 34 that opens into the second freezer compartment 30R is near the lower end, and an outlet 35 that also opens into the second freezer compartment 30R near the upper end. Are formed. A fan device 36 facing obliquely upward is provided at the outlet 35.

  When the fan device 36 is operated, the air in the second freezer compartment 30 </ b> R is sucked into the duct 33 from the inlet 34. The air that has entered the duct 33 rises toward the outlet 35, and in the process, the cold heat of the first freezer compartment 30 </ b> L is transmitted to the air via the partition wall 32. The sufficiently cooled air is blown obliquely upward by the fan device 36 to form a large air vortex in the second freezer compartment 30R. As a result, the air in the second freezer compartment 30R is agitated and becomes cold air having a uniform temperature distribution.

  As described above, the fan device 36 positively forms an airflow that flows along the wall surface of the partition wall 32, so that the cold heat of the first freezer compartment 30 </ b> L is transmitted to the airflow through the partition wall 32. The second freezer compartment 30R can be quickly cooled.

  The temperature of the second freezer compartment 30R may be lower than the target minus 18 ° C. when the environmental temperature is low or when the amount of food put inside is small. In order to prevent the second freezer compartment 30R from being too cold, the following temperature adjusting means is provided.

  The first temperature adjusting means is a cold air return duct 85 arranged so as to exchange cold heat with the air in the second freezer compartment 30R. The air in the second freezer compartment 30R transmits cold heat to the air passing through the cool air return duct 85, and the air passing through the cold air return duct 85 gives warm heat to the air in the second freezer compartment 30R. As described above, it is possible to prevent the second freezer compartment 30R from being overcooled by extracting the heat from the return air from the refrigerator compartment 20 having a higher temperature than the second freezer compartment 30R. The heat insulating material between the cold air return duct 85 and the second freezer compartment 30R is preferably thin to improve heat conduction.

  The second temperature adjusting means is an auxiliary radiator 66 disposed in the right side wall of the second freezer compartment 30R. The heat generated by the Stirling refrigerator 50 is transmitted to the auxiliary radiator 66 through the forced circulation circuit 110, and the auxiliary radiator 66 transmits the heat to the air in the second freezer compartment 30R, thereby cooling the second freezer compartment 30R. Overpass is prevented.

  The second freezer compartment 30R is provided with a temperature sensor 16 for measuring the room temperature (see FIG. 3). The control unit 15 controls the circulation pump 111 based on the temperature measurement result of the temperature sensor 16. That is, when the temperature measurement result of the temperature sensor 16 indicates that the second freezer compartment 30R is too cold, the operation is started if the circulation pump 111 is stopped, the rotational speed is increased if the operation is being performed, etc. Sufficient heat is supplied to the second freezer compartment 30R through the auxiliary radiator 66. Thereby, the temperature of 2nd freezer compartment 30R can be made to correspond with a target value correctly.

  As described above, since the internal temperature of the first freezing chamber 30L is an extremely low temperature of minus 40 ° C. or less, when moisture is brought into the first freezing chamber 30L, the moisture immediately becomes frost and becomes the first freezing chamber. It adheres to the inside of the chamber 30L. If the frost is thickly attached, it is difficult to remove the frost. Therefore, it is necessary to remove the frost before it occurs or to prevent the frost from adhering. Therefore, the following measures are taken.

  As a first countermeasure, the control unit 15 keeps the fan rotation speed of the cooling fan device 83 that blows cold air into the first freezer compartment 30L higher than usual for a predetermined time after opening and closing the door of the first freezer compartment 30L. That is, as seen in FIG. 7, the cooling fan device 83 is stopped while the heat insulating door 31L of the first freezer compartment 30L is open, but when the heat insulating door 31L is closed, the normal rotation speed (medium speed “ M ") at a higher rotational speed (high speed" H ") for a predetermined time T.

  The opening of the heat insulating door 31L means that the air outside the chamber has entered the first freezer compartment 30L, or the food to be frozen has been put into the first freezer compartment 30L. It means that new moisture has been brought into the freezer compartment 30L. Immediately after being brought into the first freezer compartment 30L, it becomes frost and adheres to the inside of the first freezer compartment. However, after the heat insulation door 31L is closed, the cooling fan device 83 rotates at a high speed and blows more air than usual into the first freezer compartment 30L to enhance the sublimation capability, so that it can be quickly returned to the non-frosting state.

  As a second countermeasure, the control unit 15 closes a damper (not shown) provided in the cooling duct 81 while keeping the rotation speed of the cooling fan device 83 high. The time for shutting off the damper is time T in FIG. Thereby, when it is necessary to increase the sublimation capacity in the first freezer compartment 30L, the cool air toward the refrigerating room 20 stops and the cool air concentrates in the first freezer room 30L, so that the sublimation capacity can be improved as intended. .

  As a third countermeasure, the control unit 15 stops a cooling fan device (not shown) that sends cold air to the refrigerator compartment 20 while keeping the rotation speed of the cooling fan device 83 high. The stop time of the cooling fan device is time T in FIG. Thereby, when it is necessary to increase the sublimation capacity in the first freezer compartment, the distribution of the cold air to the refrigerator compartment 20 is stopped and the cold air is concentrated in the first freezer compartment 30L, so that the sublimation capacity can be improved as intended. .

  As a fourth countermeasure, the defrost heater 17 is built in the heat insulating door 31L. The defrost heater 17 is arrange | positioned so that the location which faces the 2nd freezer compartment 30L may be surrounded. The controller 15 energizes the defrost heater 17 for a certain period after the door opening / closing of the heat insulating door 31L. The energization time is time T in FIG. Thereby, the frost adhering to the heat insulation door 31L can be removed reliably.

  As a fifth countermeasure, a temperature sensor 18 that measures the temperature outside the warehouse and a humidity sensor 19 that measures the external humidity are provided outside the heat insulating casing 10. In the embodiment, both the temperature sensor 18 and the humidity sensor 19 are arranged on the back surface of the heat insulating housing 10. The control unit 15 adjusts the length of time T in FIG. 7 based on the measurement results of the temperature sensor 18 and the humidity sensor 19. Specifically, T is lengthened when temperature or humidity is high. By changing the control parameters in consideration of whether or not the environment is likely to form frost in this way, a defrosting operation without waste can be performed.

    Although the embodiments of the present invention have been described above, the scope of the present invention is not limited to these embodiments, and various modifications can be made without departing from the spirit of the invention.

    The present invention is widely applicable to a refrigerator for home use or business use.

Vertical sectional view of the refrigerator according to the first embodiment of the present invention. Schematic front view of the refrigerator with the door removed Horizontal section of the refrigerator Schematic configuration diagram of cooling cycle Illustration of how the secondary refrigerant flows The perspective view explaining the piping route of a forced circulation circuit Operation timing chart

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cooling box 10 Heat insulation housing | casing 11 Partition wall 15 Control part 16 Temperature sensor 17 Defrost heater 18 Temperature sensor 19 Humidity sensor 20 Refrigeration room 30L 1st freezing room 30R 2nd freezing room 32 Partition wall 33 Duct 34 Inlet 35 Outlet 36 Fan Equipment 40 Machine room 50 Stirling refrigerator 51 Heat radiation part 52 Heat absorption part 60 Thermosiphon circulation circuit 61 High temperature side evaporator 62 High temperature side condenser 66 Auxiliary radiator 70 Secondary refrigerant circulation circuit 71 Low temperature side condenser 72 Low temperature side evaporator 80 Cooling duct 83 Cooling fan device 110 Forced circulation circuit 111 Circulation pump

Claims (5)

In the refrigerator that cools the interior by the cold heat of the heat absorption part of the Stirling refrigerator,
A refrigerator compartment is provided in the upper stage, and a first freezer compartment and a second freezer compartment are provided adjacent to each other with a partition wall in the lower stage, and the first freezer compartment generates cold air generated by the cold heat of the heat absorption part of the Stirling refrigerator. And a cooling fan device that directly blows air, and transmits the cold heat of the first freezer compartment to the second freezer compartment via the partition wall.   A duct having an inlet and an outlet opening in the second freezer compartment is provided on the side of the partition wall facing the second freezer compartment, and an air flow from the inlet to the outlet is generated in the duct. The refrigerator according to claim 1, further comprising a fan device.   A cooler to which cold heat is supplied from an endothermic part of the Stirling refrigerator is installed on the back side of the first freezer compartment, and a cold air return duct connecting the cooler and the refrigerator compartment is provided in the second freezer compartment. The cooler according to claim 1, wherein the refrigerator is installed on the back side of the refrigerator.   2. The refrigerator according to claim 1, further comprising a secondary refrigerant circulation circuit that prevents the second freezer compartment from being overcooled by the heat generated by the Stirling refrigerator.   2. The refrigerator according to claim 1, wherein the fan rotation speed of the cooling fan device is kept higher than usual for a predetermined time after opening and closing the door of the first freezer compartment.

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